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  1. Jul 2018
    1. On 2014 Dec 23, David Keller commented:

      Innovative antiviral delivery systems for patients non-compliant with pre-exposure prophylaxis

      Pre-exposure prophylaxis (PEP) is a reasonable option when adherence to condom use is imperfect. In order to improve compliance with PEP by reducing pill burden, antiviral medication could be incorporated into oral contraceptive pills prescribed to seronegative female partners in HIV-discordant couples. In cases where the discordant seronegative partner is male, other means of reducing the pill count required to deliver PEP could be used. For example, a seronegative older man with erectile dysfunction who engages in risky behaviors could be prescribed a phosphodiesterase inhibitor pill (such as sildenafil) which also includes the recommended antiviral PEP medications.


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    1. On 2015 Jul 24, Miguel Lopez-Lazaro commented:

      I agree with Dr. Baker that the SMT does not explain important aspects of the disease, and that new models of carcinogenesis should be explored. The “stem cell division theory of cancer” is a new model of carcinogenesis that integrates some features from existing theories (SMT, TOFT, and CSC model) and may provide a better framework for understanding the disease. It can explain, for instance, the cellular origin of cancer, the age distribution of the disease, the existence of metastatic cancers in the absence of primary tumors, or why a variety of factors that do not directly cause DNA alterations (e.g., mechanical, physical, chemical or neural factors) can induce cancer or modify cancer risk. http://www.ncbi.nlm.nih.gov/pubmed/26090957<br> http://www.ncbi.nlm.nih.gov/pubmed/26097879


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    1. On 2015 Jan 23, Donald Forsdyke commented:

      GC% DIFFERENCES NOT CAUSED BY CONVENTIONAL SELECTION

      Its average base composition (GC%) is a characteristic of a biological species. The present work questions the view that GC% differences between species reflect responses to conventional selective pressures on organism function. Thus, the result “challenges the causes and possible functional roles (if any) of GC content variations in grass and Monocot genomes” (1). Likewise, in earlier work, the authors noted that “it is not clear why GC content in introns should also be selected for. Thus, we think that selective hypotheses are not clearly established and are currently insufficient to explain all the data adequately” (2).

      To resolve this it would be interesting to examine the GC% values of sympatric, so-called “sibling species” (espèces jumelles, Geschwisterarten). Here phenotypic differences are minimal. Indeed, it has been shown that very small differences in GC% should suffice to spark speciation. These initiating GC% differences could later be obscured by pressures on the phenotype that affect GC%. But when such phenotypic differentiation was minimal, traces of these initiating events might remain (3).

      Speciation is still mainly studied in complex organisms. Virus species that infect the same host cell have less scope for developing phenotypic differences and can be construed as sibling species. Indeed, we might recall that the mid-20th century revolution in molecular biology owed much to physicists who studied the simplest living systems – viruses that infect bacteria.

      Considering the retroviruses HIV1 and HTLV1 that both infect CD4 T lymphocytes, we find that HIV1 has one of the lowest GC% values known and HTLV1 has one of the highest GC% values known. Large differences are also found when other related viral species share a host cell. Since minute GC% differences can initiate divergence into recombinationally isolated species, it can be assumed that, in the absence of major superceding phenotypic differences, these GC% differences have remained and expanded in HIV1 and HTLV1 (4).

      Viewed from a selective perspective, an ancestral retrovirus by virtue of avoiding recombinational blending with its cell-mates, should have been able to develop sufficient functional variation “in sympatry” to achieve full speciation while retaining phenotypic characters needed for the shared intracellular environment. All this harkens back to Romanes who in 1886 proposed that initiation of divergence into species could precede subsequent phenotypic changes (5).

      (1) Clément Y, Fustier M-A, Nabholz B, Glémin S. (2015) Genome Biology and Evolution. (In press) doi:10.1093/gbe/evu278

      (2) Glémin S, Clément Y, David J, Ressayre A. (2014) GC content evolution in coding regions of angiosperm genomes: a unifying hypothesis. Trends in Genetics 30, 263-270.

      (3) Forsdyke DR (2001) The Origin of Species Revisited. McGill-Queen’s University Press, Montreal.

      (4) Forsdyke DR (2014) Implications of HIV RNA structure for recombination, speciation, and the neutralism-selectionism controversy. Microbes and Infection 16, 96-103 doi: 10.1016/j.micinf.2013.10.017.

      (5) Romanes GJ (1886) Physiological selection: An additional suggestion on the origin of species. Journal of the Linnaean Society, Zoology 19, 337-411.


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    1. On 2016 Oct 03, Duke RNA Biology Journal Club commented:

      Overall, we were very impressed with the thoroughness of the paper - we rarely found an experiment that did not have orthogonal experimental validation along with the necessary controls. Leaving the discussion, we were convinced that NRAV plays a role in IAV host immune response and possibly a broader viral response, which control experiments hinted at.

      More critically, we felt the paper focused on creating a broad understanding of NRAV’s function in immunity while leaving many loose ends in mechanistic understanding. For instance, an undeveloped part of this paper was the role of ZONAB in NRAV transcriptional repression. While the pulldown assays in Fig 6 I and J suggest ZONAB acts as a transcription factor of MxA, it’s not clear how this is regulated in the presence of NRAV. Perhaps performing a mass spec analysis of all proteins interacting with NRAV, see Fig 6H, would help uncover the rest of the mechanism. Additionally, our group had concerns with Fig 7. The determination of such a long RNA with structure prediction software is risky since longer RNA is more likely to be predicted to fold into many different structures with similar free energy compared to a much smaller RNA, the general query molecules for these programs. We would prefer the authors confirm these predictions with biochemical assays such as RNAse protection and SHAPE-based assays. We were also curious why the NRAV truncation mutants were not used to determine the ZONAB interaction site using pulldown methods.

      To summarize, this paper scratches the surface of NRAV’s role in viral host immunity. We hope the authors continue to provide more depth to the story by determining how NRAV is regulated, how NRAV changes histone methylation patterns at ISG transcription sites and how ZONAB specifically fits into this response. We look forward to learning more about the role of lncRNA in the immune response and will be interested to see how the other lncRNAs from Fig 1A fit into this emerging field.


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    1. On 2015 Jan 06, IGSJC - The International General Surgery Journal Club commented:

      First author Adil Haider will be joining IGSJC to discuss "Incremental Cost of Emergency Versus Elective Surgery" on Twitter January 14-15, 2015. For the month of January, Annals of Surgery has opened access to the article (available at http://bit.ly/IGSJC_Jan15), and all are welcome to contribute to the discussion.

      For tips on getting started, read http://igsjc.wordpress.com/guide-for-new-twitter-users/. Then, read the article, and return to Twitter on January 14 to take part!

      Search on Twitter for #IGSJC (https://twitter.com/hashtag/igsjc) for the latest info and to join the chat.


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    1. On 2014 Dec 30, William Grant commented:

      Here are some papers not included in this review showing benefits of vitamin D testing. Peiris AN, Bailey BA, Grant WB, Mascitelli L. Vitamin D testing. Lancet 2012 May 5;379:1699-1701.

      Der T, Bailey BA, Youssef D, Manning T, Grant WB, Peiris AN.,Vitamin D and prostate cancer survival in veterans. Military Med. 2014;179 (1) :81–84.

      Peiris AN, Bailey BA, Manning T. Relationship of vitamin D monitoring and status to bladder cancer survival in veterans. South Med J. 2013 Feb;106(2):126-30.

      Bailey BA, Manning T, Peiris AN. Vitamin D testing patterns among six Veterans Medical Centers in the Southeastern United States: links with medical costs. Mil Med. 2012 Jan;177(1):70-6.

      Of course some may have been published after your literature search was completed. However, they do support the benefits of vitamin D testing among hospital patients.

      Also, this paper is supportive in that it found that patients in the ICU with very low 25OHD concentrations benefited from vitamin D supplementation. Amrein K, Schnedl C, Holl A, Riedl R, Christopher KB, Pachler C, Urbanic Purkart T, Waltensdorfer A, Münch A, Warnkross H, Stojakovic T, Bisping E, Toller W, Smolle KH, Berghold A, Pieber TR, Dobnig H. Effect of High-Dose Vitamin D3 on Hospital Length of Stay in Critically Ill Patients With Vitamin D Deficiency: The VITdAL-ICU Randomized Clinical Trial. JAMA. 2014 Oct 15;312(15):1520-30.

      One of the impediments to acceptance of vitamin D seems to be the lack of supportive trials. The trials have not supported the ecological and observational studies largely because the trials have not been properly designed. Too often, people with normal to high 25OHD concentrations are enrolled and given a small amount of vitamin D. The proper way to conduct such trials was outlined recently in this paper: Heaney RP. Guidelines for optimizing design and analysis of clinical studies of nutrient effects. Nutr Rev. 2014 Jan;72(1):48-54.

      Disclosure I receive funding from Bio-Tech Pharmacal (Fayetteville, AR) and Medi-Sun Engineering, LLC (Highland Park, IL).


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    1. On 2017 Feb 20, Stuart MacGregor commented:

      Thank you for the bug report Christoph. Following your bug report (January 2016), the bug was fixed on the VEGAS2 web-based version in January 2016 but unfortunately not until January 2017 on the VEGAS2 offline version. Users who ran the top % test (not the default option) using VEGAS2 prior to these dates (or using the now retired VEGAS1) should re-run their analysis using VEGAS2. There is an FAQ item on this at https://vegas2.qimrberghofer.edu.au


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    2. On 2017 Jan 18, CHRISTOPH LANGE commented:

      The VEGAS/VEGAS2 software can provide p-values for the top-percentage statistic that are anti-conservative, as the computation of the null-distribution is incorrect. In our technical report, we discuss the issue and provide code that, if included in VEGAS/VEGAS2, will provide correct p-values.

      http://biorxiv.org/content/early/2017/01/17/101014


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    1. On 2015 Feb 10, Diederik W J Dippel commented:

      Dear dr Radecki, in my view the best way to synthesize evidence is the Cochrane collaboration's approach. They have done this for IV thrombolytic treatment and will quite likely update the review of intra-arterial treatment. I would highly recommend reading that report which will undoubtedly offer more insight and detail. Diederik Dippel


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    2. On 2015 Feb 06, Ryan Radecki commented:

      Post-publication commentary: "MR-CLEAN & the New Golden Age"

      I, among many others, have been highly skeptical of thrombolytic therapy and its role in the treatment of acute ischemic stroke. As has been well-documented, a few trials were positive, many were neutral, and a few were stopped early for harm or futility. To most of us, this indicates a therapy for whom only a small subset of those treated are ideal candidates for benefit, and the margin between benefit and harm is razor thin.

      In my previous posts, I’ve sighed wistfully at the hope of The Next Big Thing in stroke treatment – local endovascular therapy, akin to percutaneous coronary intervention. However, each major endovascular trial published in the New England Journal last year failed to demonstrate benefit.

      MR-CLEAN is different. MR-CLEAN is rather unambiguously positive. To be zero or minimally disabled? The endovascular intervention is favored 12% to 6%. “Functionally independent”, a modified Rankin Scale of 0-2, favors endovascular intervention 33% to 19%. A number needed to treat of, apparently, ~8 for independence is nothing to scoff at.

      But why?...

      http://www.emlitofnote.com/2014/12/mr-clean-new-golden-age.html


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    1. On 2015 Feb 02, NephJC - Nephrology Journal Club commented:

      This study was discussed on Jan 20th and 21st in the open online nephrology journal club, #NephJC, on twitter.

      Introductory comments are available at the NephJC website. The discussion was quite detailed, with more than 45 participants, including nephrologists, fellows and residents with great insight provided by participation of the first author, Areef Ishani.

      A transcript and a curated (i.e. Storified) version of the tweetchat are available at the NephJC website.

      The highlights of the tweetchat were:

      • The authors have undertaken a meticulous and well conducted epidemiological study to explain the risks of parathyroidectomy in the dialysis population, with research funding from the manufacturer of cinacalcet (which is an alternative to surgical parathyroidectomy).

      • There were concerns raised about the lack of matched controls who did not undergo surgery (especially given the contrasting result from the previous study using USRDS data, generalizability of the post surgical hospitalization data and the lack of long term follow up. However, this study does represent a solid estimate of the immediate and 1-year mortality following parathroidectomy in this population. The discussion, and the comments from the author, also helped to explain the steps taken and the reasons behind these design decisions.

      • The final question of the optimal management of secondary hyperparathyroidism still remains unanswered. Opinion was widely divided on the ideal study: most likely a randomized trial of surgical versus medical treatment of uncontrolled secondary hyperparathyroidism with clinically relevant outcomes, but with possible comparator arms being calcimimetic therapy, surgical parathyroidectomy or even placebo, suggesting a lack of consensus.

      Interested individuals can track and join in the conversation by following @NephJC or #NephJC, or visit the webpage at NephJC.com.


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    1. On 2014 Dec 18, Tom Kindlon commented:

      The evidence is not there to recommend CBT and GET to improve employment outcomes in CFS

      For over a decade now, some individual patients with Chronic Fatigue Syndrome (CFS)* in Great Britain and Ireland (and probably elsewhere) have been pressurised by insurance companies and occupational health professionals into undertaking graded exercise therapy (GET) and the form of cognitive behaviour therapy (CBT) that is based on scheduling increases in activity. This seems to have been largely due to hype around the efficacy of GET and CBT and extrapolations from subjective measures, as the evidence that such interventions are efficacious in restoring the ability to work is week.

      Based on the information in Tables 1, 3 and the qualitative results from this paper, CBT and GET have again been recommended to occupational professionals in these workshops.

      A lot of the evidence regarding CBT and GET and their effect on occupational outcomes in CFS has been summarised in a review (1). For some reason this is quoted sometimes as justifying claims it is evidence-based to say that GET and CBT have been shown to restore the ability to work in CFS. However the data is far less impressive. It is summarised in table 6 of that paper. The accompanying text says: "Among the 14 interventional trials with work or impairment results after intervention, there were too few of any single intervention with any specific impairment domain to allow any assessment of association."

      The PACE Trial is by far the biggest trial of these therapies in the field. It shows neither CBT nor GET led to an improved rate of days of lost employment [Means (sds): APT: 148.6 (109.2); CBT: 151.0 (108.2); GET: 144.5 (109.4); SMC (alone): 141.7 (107.5)] (Table 2) (2). Neither CBT nor GET led to improvements in numbers receiving welfare benefits or other financial payments (Table 4). These results are in contrast to the self-reported improvements in fatigue, physical functioning and some other measures (3).

      A major audit of Belgian CFS rehabilitation (CBT & GET) centres also gives real-world data on the issue (4). The sample size was large, with over 600 patients with a confirmed diagnosis of CFS (using the Fukuda et al. criteria (5)) taking part. It "comprised on average per patient 41 to 62 hours of rehabilitation" It found that "physical capacity did not change; employment status decreased at the end of the therapy." Again improvements were found in some self-reported measures.

      It should be noted that a large assortment of abnormalities have been found in terms of the exercise response in CFS, with high rates of adverse reactions have been reported in patient surveys from CBT and GET, particularly with the latter, again putting in to question any recommendations of CBT and GET for CFS (6,7).

      All in all, I question suggestions that occupational health professionals should be recommending CBT and GET to individuals with CFS.

      • I'll use the term for consistency.

      References:

      (1) Ross SD, Estok RP, Frame D, Stone LR, Ludensky V, Levine CB. Disability and chronic fatigue syndrome: a focus on function. Arch Intern Med. 2004 May 24;164(10):1098-107. http://archinte.ama-assn.org/cgi/content/full/164/10/1098 or http://archinte.ama-assn.org/cgi/reprint/164/10/1098

      (2) McCrone P, Sharpe M, Chalder T, Knapp M, Johnson AL, et al. (2012) Adaptive Pacing, Cognitive Behaviour Therapy, Graded Exercise, and Specialist Medical Care for Chronic Fatigue Syndrome: A Cost-Effectiveness Analysis. PLoS ONE 7(8): e40808. doi:10.1371/journal.pone.0040808

      (3) White PD, Goldsmith KA, Johnson AL, Potts L, Walwyn R, et al. (2011) Comparison of adaptive pacing therapy, cognitive behaviour therapy, graded exercise therapy, and specialist medical care for chronic fatigue syndrome (PACE): a randomised trial. Lancet 377: 823-836.

      (4) [Fatigue Syndrome: diagnosis, treatment and organisation of care] KCE Reports 88. (with summary in English). Accessed: 6th August, 2012. https://kce.fgov.be/publication/report/fatigue-syndrome-diagnosis-treatment- and-organisation-of-care

      (5) Fukuda K, Straus SE, Hickie I, Sharpe MC, Dobbins JG, Komaroff A. The chronic fatigue syndrome: a comprehensive approach to its definition and study. International Chronic Fatigue Syndrome Study Group. Ann Intern Med. 1994 Dec 15;121(12):953-9.

      (6) Twisk FN, Maes M. A review on cognitive behavorial therapy (CBT) and graded exercise therapy (GET) in myalgic encephalomyelitis (ME) / chronic fatigue syndrome (CFS): CBT/GET is not only ineffective and not evidence-based, but also potentially harmful for many patients with ME/CFS. Neuro Endocrinol Lett. 2009;30(3):284-99. Review.

      (7) Kindlon T. Reporting of Harms Associated with Graded Exercise Therapy and Cognitive Behavioural Therapy in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Bulletin of the IACFS/ME. 2011;19(2):59-111. http://www.iacfsme.org/BULLETINFALL2011/Fall2011KindlonHarmsPaperABSTRACT/ta bid/501/Default.aspx


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    1. On 2016 Jun 02, David Keller commented:

      Information Theory versus FDA regulations governing colon cancer screening

      The ColoGuard colorectal cancer screening test is composed of 7 different sub-tests, including an assay for occult fecal hemoglobin, 5 assays for specific DNA changes associated with malignancy, and an assay for normal DNA to standardize the sample. The results of these seven subtests are combined using complex equations to yield a Composite Score ("CS") ranging from 0 to 1000 and directly related to the likelihood of colon neoplasia. A CS of 183 was established as the threshold for further screening with colonoscopy; If the CS is larger than or equal to 183, the patient is sent for colonoscopy, and if the CS is lower than 183, the patient is spared further testing. [1,2]

      The FDA prohibits the release of any of the test data generated by the ColoGuard system except the single bit of information in the final result: positive or negative, over or under the threshold, yes or no to colonoscopy, 1 or 0. This one bit of information represents the distillation of the combined results from the seven sub-tests, but much of the information in those test results is lost in the process of determining the value of that single bit.

      Now, consider the composite score, which can vary from 0 to 1000. How many bits of information does the CS convey? The answer is nearly 10 bits of information, because 10 bits can represent 0 through 1023 in decimal numeral, or 000000000 through 111111111 in binary. So, we start with a composite score which requires 10 bits of information to quantify the patient's risk of colon cancer, and we finish by distilling the result down to a single bit of information: positive or negative. In so doing, we have thrown away 9 perfectly good bits of information.

      A negative ColoGuard result conveys just one bit of information about the status of the patient's colon epithelium, informing us only that the composite score was in the range of 0 to 182, a range which requires almost 8 more bits to specify precisely. The FDA forces Exact Sciences to throw away almost 7 perfectly good bits of information about the patient's colon epithelium. These discarded 7 bits tell the patient whether his composite score was 0 or 182 or somewhere in between, given an overall negative screening result.

      The purpose of the FDA regulation is to force clinicians to adhere strictly to the decision threshold for colonoscopy of 183, which has been validated in a large clinical trial. But what of the patient who develops "soft" or borderline indications for colonoscopy some time later. The clinician may be undecided whether the patient's borderline signs and symptoms warrant a diagnostic colonoscopy or not. Knowing that the patient's recent composite score had been 17 or 170 could help tip the decision one way or the other.

      We may learn over time that composite scores can exhibit informative trends over time. What is the significance of a composite score rising from 15 to 160 over 3 years? We will never know if we throw away the 7 bits that let us quantify the composite score with precision.

      We have discussed the loss of clinical information which occurs when the ColoGuard composite score is distilled down to one bit. There is also substantial loss of information when the Cologuard sub-test results are crushed together to derive the composite score. In my next comment, I will discuss some effects of the loss of information which occurs related to ColoGuard's fecal hemoglobin concentration sub-test. [3] We will learn how the FDA's prohibition of patient access to Cologuard's internal sub-test results could be harmful to patients.

      References

      1: Imperiale TF, Ransohoff DF, Itzkowitz SH, Turnbull BA, Ross ME; Colorectal Cancer Study Group. Fecal DNA versus fecal occult blood for colorectal-cancer screening in an average-risk population. N Engl J Med. 2004 Dec 23;351(26):2704-14. PubMed PMID: 15616205.

      2: Imperiale TF et al. Online Supplement to the above print article, accessed on 4/18/2016. http://www.nejm.org/doi/suppl/10.1056/NEJMoa1311194/suppl_file/nejmoa1311194_appendix.pdf

      3: PubMed Commons comment: http://www.ncbi.nlm.nih.gov/pubmed/27235008#cm27235008_15979


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    1. On 2016 Mar 13, Tamir Tuller commented:

      We (and everyone) know that correlation on binning may be misleading if reported in a non-transparent way; specifically binning tends to increase the correlation (but usually has a much weaker effect on the p-value). However, we frankly do not understand why this ‘lecturing’ about the topic appears here (next to our study). Our study includes various sophisticated statistical tests, the binning procedure is described at the beginning in a coherent manner, the correlation for various bin sizes is also reported (one can learn about the relation between binning and correlation simply by looking at figure S5 without the need for this unnecessary correspondence :-)), etc. Thus, we believe that the nature of the signal and the challenging data should be very clear to readers who thoroughly read the paper (but we guess that it may be misleading, as any other paper would, if you do not bother to read all the details :-)).

      The statistical analysis in papers in our field (if they are performed accurately) should consider various aspects including non-trivial biases in the data, discretization, various confounding variables/explanations, various aspects of molecular evolution, huge datasets, etc. Thus, the reader and not only the author should consider them when evaluating the results; specifically, the strength of a correlation should be evaluated in the light of all these aspects. The aim of mentioning other papers and ‘top statisticians’ was to demonstrate that there are many people (as opposed to Plotkin/Shah/Cherry) that do understand this point.

      If the number of points in a typical systems biology study is ~300, the number of points analyzed in our study is 1,230,000-fold higher (!); a priori, a researcher with some minimal experience in the field should not expect to see similar levels of correlations in the two cases. Everyone also knows that increasing the number of points, specifically when dealing with non trivial NGS data, also tends to very significantly decrease the correlation. The aim of the binning was to align our signal to previously reported signals in the field (in terms of number of points), and as mentioned the paper includes many other analyses that give the reader a greater context for the signal (including an explicit graph reporting the relation between bin size and the correlation); in addition the non-binned correlation (0.02-0.07) is comparable to the level of correlation between two Hi-C measurements (~0.05) from different labs (!). It is clear that a typical signal in our field (e.g. higher than the correlation of 0.12 or even the “high” 0.38 mentioned in your paper Weinberg DE, 2016) if transferred via such a noisy/biased ‘channel’ with increased number of points will be order of magnitudes lower than our non-binned data.

      We, of course, do not expect that further back-and-forth will convince Plotkin and Shah of our points. But hopefully this exchange will at least have some value to the field for scientists who work to draw inferences from genomic datasets; specifically, we hope that other scientists will learn to thoroughly consider all the aspects mentioned above and below when reading/writing a scientific paper.

      BTW: regarding the correlation 0.12 that was improved to 0.38 in the new study. In the new study (Weinberg DE, 2016) you still did not perform many of the required statistical controls (among others control for Kozak sequence and AA bias) according to our review [http://www.cs.tau.ac.il/~tamirtul/Shah_et_al_review.pdf].

      Tamir Tuller & Alon Diament, Tel-Aviv University, March 13, 2016


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    2. On 2016 Mar 09, Joshua Plotkin commented:

      Hopefully this exchange now illustrates that correlations on binned data are terribly misleading. In the paper by Diament et al 2014, the authors never reported the actual correlation (r = 0.022) between two genomic measurements; instead they reported correlations on binned data (r = 0.86). As a result, the amount of variation in 3D position explained by codon usage, which is the central claim of the study, was inflated by 1,500-fold.

      There is no need to consult “top professional statisticians” to understand the obvious fact that binning data tends to inflate correlations, and that it has no scientific justification regardless of the size of a dataset.

      Diament and Tuller offer one non-scientific justification in their reply: that previous publications in “top journals” have done the same thing, citing Ghaemmaghami S, 2003 and Shah P, 2013 as examples. Even if this were true, appealing to journal name is not a strong justification for repeating statistical errors. Moreover, in fact, both cited studies used binning only to graph the data, showing also the variation within each bin, whereas the correlations were calculated on the unbinned data.

      We agree with Diament and Tuller that r = 0.12 should not have been described as a “strong” correlation by Shah P, 2013. (The same analysis on an improved experimental dataset yields r = 0.38, Weinberg DE, 2016). However, unlike Diament and Tuller, we maintain that scientists must nonetheless report the actual correlations between measured quantities, instead of inflating correlations by binning, which would have produced a misleading r = 0.62 in the case of Shah et al. 2013.

      We do not expect that further back-and-forth will convince Diament and Tuller of these points. But hopefully this exchange will have some value to the field of scientists who work to draw inferences from genomic datasets.

      --Joshua Plotkin & Premal Shah, University of Pennsylvania, March 9 2016


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    3. On 2016 Mar 05, Tamir Tuller commented:

      Plotkin couldn’t (and shouldn’t) be a reviewer of our paper simply since he was in our list of reviewers to exclude when the paper was submitted (unfortunately, indeed Plotkin’s & Shah’s comment here demonstrates that many of the details in our paper were completely overlooked by them in the biased ‘review’ they provide here, as all the raised issues were thoroughly answered in the original manuscript). Specifically in our data there were 369,000,000 initial points that were binned to up to 64,000 (!) bins (not 2 points! :-) ). The comment and answer to Cherry actually include all the important details regarding Plotkin’s & Shah’s comment. As noted, the other reviewers (and bio-statisticians that were presented the study) were, of course, aware of the binning process and found the paper interesting, correct and worthy of publication. We think that a discussion about binning (that it seems that Plotkin & Shah would like to promote) should actually include their own recent study (Shah P, 2013): there you can learn among others that in Shah P, 2013 Plotkin & Shah report in the abstract a correlation which is in fact very weak (according to their definitions here), r = 0.12, without controlling for relevant additional fundamental variables, and include a figure of binned values related to this correlation. This correlation (0.12) is reported in their study as “a strong positive correlation”. It is also important to mention that the number of points used for computing this correlation is more than one order of magnitude lower than the number of points/bins related to some of the correlations we report.

      Given their comment here, it is probable that Poltkin & Shah’s paper would not have been published (at least in its current form) had they reviewed it themselves. :-)

      Our full critical comment on (Shah et al., 2013) can be found here: Shah P, 2013 (or here http://www.cs.tau.ac.il/~tamirtul/Shah_et_al_review.pdf ).

      A point by point answer to Plotkin’s & Shah’s ‘review’ can be found here http://www.cs.tau.ac.il/~tamirtul/Plotkin__reply.pdf

      Our full answer to Cherry’s, Plotkin’s & Shah’s claims regarding binning can be found here: http://www.cs.tau.ac.il/~tamirtul/Cherry_reply.pdf

      Tamir Tuller & Alon Diament, Tel-Aviv University, March 5, 2016


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    4. On 2016 Feb 04, Joshua Plotkin commented:

      Weak effects made to appear strong by inflated correlation coefficients (reply)

      The titular claim of this paper is that codon usage and gene function are “strongly correlated” with physical proximity within the cell. To support this claim, the authors report correlations between various features of genes, such as codon usage, expression level etc, with 3D genomic organization data. Unfortunately, as Joshua Cherry has pointed out on PubMed commons (Nov 24, 2015), these correlations are all based on binned datasets. By systematically binning the data, the authors remove noise and artificially inflate the strength of the correlation, so that the resulting correlation coefficient does not reflect the actual strength of correlation in the data. In the extreme case of n=2 bins, for example, all the correlations would be r=1.

      We raised these concerns — the exact same ones Joshua Cherry expressed post-publication — in our original review of the submitted manuscript. We submitted our review to Nature Communications on May 21, 2014, and we never heard back from the journal or saw a revised version of the manuscript. It is now clear that our concerns were ignored both by the authors and by editors at Nature Communications.

      Artificially inflating correlations by binning data is a serious issue in ongoing biological studies. By posting our original review of this manuscript, alongside Cherry's post-publication critique, we hope to draw awareness and open discussion regarding this scientific issue.

      Joshua Plotkin & Premal Shah, University of Pennsylvania, February 4, 2016

      ----ORIGINAL REFEREE REPORT SUBMITTED May 21 2014----

      Remarks to the Author:

      The manuscript by Diament et al. aims to understand how the three dimensional arrangement of a eukaryotic genome is organized. The natural hypothesis is that functionally related genes are positionally closer to each other in space -- a hypothesis that has been proposed earlier but with limited empirical support. Here, the authors claim that earlier studies failed to identify a strong relationship between position and function due to lack of appropriate metrics to assess functional similarity between genes. The authors propose a "novel" metric based on patterns of codon usage and they demonstrate a putatively strong relationship between functionally related genes and their proximity in 3-D.

      The manuscript is severely flawed from both biological and statistical stand-points, and is not fit for publication. Following are my detailed comments:

      1) The "novel" CUBS method proposed by the authors is not novel at all. There is a rich literature of using Kullback-Liebler based distance metrics for studying patterns of codon usage, which the authors have completely ignored. Although, their metric is a symmetric version of KL-distance, the entire basis of this metric is not novel.

      2) The entire analysis is predicated on the assumption that functionally similar genes have similar patterns of codon usage. The only work cited in support of this notion is De Bivort et al 2009, where those authors found that amino acid metabolism might play a role in affecting protein composition for certain functionally related proteins in yeast. However, even there the extent of this effect was found to be limited to 20,000-60,000 residues, which constitutes less that 2% of the entire genome. To say that this pattern holds not only across the entire genome but also across four other species demands quite a stretch of imagination.

      3) More importantly, every single correlation reported in the paper is based on binned data. Although it is sometimes appropriate to bin the data for visualization purposes, it is entirely without merit to report correlation coefficients (and associated p-values) on binned data. This fact id demonstrated by comparing figures 3D and S2A, where changing the bin-size effects the apparent "correlation". All the correlation calculated should be based on the raw data and "improving statistical accuracy" is not a vlid justification for arbitrarily binning data. This problem of correlation-inflation due to binning the data is quite serious (eg Kenny & Montanari J Comput Aided Mol Des. 2013). Based on their own figures 3D and S2A, it seems clear that their results either have very small effect or do not at hold at all when analyzing the actual raw data.

      4) This statistical problem (#3) is further compounded by the fact that each data point in the correlations is based on a pair of genes, and hence the points are not independent of each other -- whereas t-tests used to assess significance assume independence. The standard way to deal with such data is to use Mantel's test or one of its several derivatives. The authors also need to take into account issues related to multiple regressions. Its likely that several of the gene features used as proxies for function are, again, highly correlated with each other. Once again, the nominal statistical significance of the results is inflated by failing to account for these dependencies.

      5) Finally, the authors make no attempt to explain why the data in their plots are so non-linear and even non-monotonic? Its clear that in several of the plots the relationship between CUBS and the predictor is highly non-linear, and that the linear fit is extremely poor. However, the authors make no effort to explain or even understand these patterns. Could they be an artifact of the data? If so, how does it affect the results?

      6) Moreover, the correlation coefficients reported in most of their plots make no sense whatsoever. For instance, in Fig1B, the best-fit regression line of CUBS vs PPI barely passes through the bulk of the data, and yet the authors report a perfect correlation of R=1.

      The issues above are so severe (starting from the unjustified assumption that similar codon usage implies similar gene function, which underlies the entire study) that revision cannot possible rectify these problems.

      Remarks to the Editor: none


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    5. On 2016 Mar 08, Joshua L Cherry commented:

      In their response to my comment, Diament and Tuller not only attempt to defend their use of a procedure that dramatically inflates correlation coefficients, but advocate for its wider use, which would be most unfortunate. Nothing in their response justifies this procedure or refutes the warnings against it that I cited. I address their points briefly below, and in more detail here.

      Statistical Significance vs. Effect Size

      The response makes much of the high statistical significance of the correlations. This does nothing to address my comment, which was about effect size. A weak correlation, however statistically significant, is not a strong correlation.

      Large Sample Size

      The response emphasizes the large number of data points in the authors’ data set, but this in no way justifies their correlation-inflating procedure. The large size of the dataset only allowed the authors to bin and average large numbers of data points, which only exacerbated the problem by leading to a more dramatic inflation of the correlation coefficients. The response also seems to imply that a large sample size will cause a strong correlation to yield a low correlation coefficient, which is incorrect.

      Other Evidence

      The response claims that "The conclusions of our paper have also been tested in a recent study (Diament A, 2015), where we showed that 3D distances predicted by CUFS can be employed to reconstruct an improved 3D model of the yeast genome." If CUFS data did improve estimates of 3D distance, this would not justify or vindicate the inflation of correlation coefficients by binning and averaging. Furthermore, as explained in my more detailed response, there is little evidence that the 3D distance estimates were actually improved.

      Measurement Errors

      The response repeats the article’s argument about measurement noise, but this argument is flawed. It is true that a strong underlying correlation coupled with sufficient measurement error could produce a weak apparent correlation with the observed properties. It does not follow that a weak correlation with these properties implies a strong underlying correlation. Counterexamples are common--probably the rule rather than the exception--and include Francis Galton’s classic studies of height among relatives. Galton and Pearson could easily have arrived at larger “correlation coefficients” through binning, but doing so would have defeated their purpose and been a great setback for statistics and quantitative genetics.

      Diament and Tuller claim, based on the low correlation coefficient between two sets of yeast 3D distances (r=0.05), that the maximum possible CUFS/3DGD correlation is 0.05. Were this correct, it would only argue for an underlying correlation of 0.022/0.05=0.44 for yeast, far short of the reported r=0.86. The claimed maximum is in fact incorrect, for several reasons:

      • If the correlation coefficient between replicate datasets were 0.05, the correct maximum would be sqrt(0.05)=0.22 (the inferred correlation of either replicate with reality), from which one can argue only for an underlying r=0.1.

      • Diament and Tuller did not analyze data from replicates, but compared the data that they used in the article to values derived from an older experiment based on a different technique. The low correlation between the datasets may be due mainly to noise in the other dataset.

      • The original response submitted by Diament and Tuller included two other comparisons that did not suffer from the above problem, and these yielded much higher estimates of reliability: r=0.39 and r=0.54. This information was omitted from the version of the response posted by Tuller.

      Diament and Tuller argue that r=0.05 for the two datasets, calculated as Spearman intended, absurdly implies that "any attempt to study 3D genomic organization using Hi-C...is futile”. In reality it implies only that these particular datasets are not very similar, which is not absurd, and undoubtedly true. Their apparently preferred alternative--binning the data to obtain a high correlation coefficient and concluding that the measurements are very similar--is clearly incorrect.

      Concluding Remarks

      The correlations between 3DGD and CUFS, though statistically significant, are quite weak, and should have been reported as such. The available information does not support the contention that they reflect strong correlations made weak by measurement noise. That others have committed or overlooked a "common error" is not an argument in its favor. That correlations coefficients in a field are often weak is no reason to inflate them or describe weak correlations as strong. It would be one thing to argue that a correlation coefficient of 0.022 tells us something important, but it is quite another to report an inflated correlation coefficient of 0.86 and describe the correlation as strong, as done by the authors.


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    6. On 2016 Feb 27, Tamir Tuller commented:

      We are happy to report that the paper, including the binning procedure, was presented to top professional statisticians who found the paper very interesting. The comment by Cherry was submitted to Nature Communications as a comment, and was reviewed by at least two professional reviewers. Based on the review the decision was that the comment is not required as it does not teach us anything new and is irrelevant/incorrect in this context. Specifically, it is known that binning tends to increase the correlation; however, the opposite is also true, when there are more points the correlations tend to be lower. In the analyzed data, the binning procedure was described very clearly and mentioned at the beginning of the paper; there were 369,000,000 initial points that were binned to up to 64,000 (!) bins (not 2 points!) so that the correlations will be comparable to correlations reported in all previous systems biology studies in recent years (actually the number of points is still orders of magnitudes (!) higher than previous systems biology studies that we know of). As described in the link to the detailed reply (see below) the obtained correlations with raw data are similar to the ones obtains between two Hi-C measurements, demonstrating that indeed given the nature of the data the correlations are very high. A detailed reply to Cherry’s comment can be found here: http://www.cs.tau.ac.il/~tamirtul/Cherry_reply.pdf. In this link, we further explain why Cherry’s claims were thoroughly addressed in the original manuscript, and that the methods and results were presented in a transparent manner. Most importantly, we reiterate that the relation between variables has been subject to stringent statistical tests, and that the observed signals are indeed strong with respect to expected and previously reported ones in large-scale genomic studies. In addition, we illustrate again that the reported correlations are comparable to the maximal correlation expected when comparing large scale noisy data after quantization. Finally, we show that the correlations reported in our study are similar to the correlations obtained between two Hi-C experiments; thus, if we follow Cherry’s line of thought, we actually should absurdly conclude that the Hi-C protocol in general is problematic. We discuss the generality of our conclusion to systems biology analysis of Next Generation Sequencing (NGS) data.


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    7. On 2015 Nov 24, Joshua L Cherry commented:

      Weak effects made to appear strong by inflated correlation coefficients

      Diament et al. claim that the three-dimensional distances between eukaryotic genes are strongly correlated with differences in codon usage and gene function. These claims are based on correlation coefficients calculated by an illegitimate procedure that grossly inflates their magnitude. The correlations are in reality very weak, and the article’s conclusions are therefore unjustified.

      Diament et al. report high values (0.74-0.96) for Spearman’s rank-order correlation between measures of codon usage dissimilarity (CUFS) and 3D distance between genes (3DGD). These impressive values, however, are not the true correlation coefficients between the variables. Rather, they are the correlation coefficients of average values for bins of thousands of data points with similar values of CUFS. This binning and averaging procedure can be expected to yield high values in the presence of very weak correlations. The authors describe the process as "reducing biological noise through averaging". In reality it suppresses much of the variation in one variable that is not explained (in the statistical sense) by the other, making it appear as though the explained variation is a larger fraction of the total, and inflating the correlation coefficient accordingly. A miniscule correlation can be made to look like a strong correlation with this procedure, so long as the expected value of one variable mainly increases with the value of the other. Computing correlations based on averages is described by one textbook [1] as a “common error” that “can easily lead to an inflated correlation coefficient”, and correlations inflated in this way have been criticized elsewhere [2,3].

      Supplementary Fig. 5 of the article suggests that the true correlations between CUFS and 3DGD, corresponding to one data point per bin, are quite weak. Using data provided by the authors, I have found that they are very weak indeed: the Spearman’s correlation coefficients are 0.019, 0.022, 0.025, 0.071, and 0.034 for S. pombe, S. cerevisiae, A. thaliana, M. musculus, and H. sapiens respectively. The central claims of the article are therefore unfounded, as the reported strong correlations are an artifact of the binning procedure.

      The weakness of the correlations is evident in the meager sensitivity of averaged 3DGD to CUFS, which is apparent in Fig. 2 of the article. For example, for S. cerevisiae, for which a correlation coefficient of 0.85 was reported, averaged values of 3DGD vary only from ~3.0 for the lowest CUFS values to ~3.1 for the highest (a few outliers approach 3.3, but, as the authors argue, these are not meaningful). This is only a small fraction of the variation in 3DGD values, which range from 1 to 13 with a standard deviation of 0.72.

      Another perspective is provided by the distributions of CUFS values for different 3D distances. Distributions in S. cerevisiae are shown in here for distances between 1 and 5, which encompass 99.8% of the gene pairs (for larger distances the distributions vary more widely but are dominated by pairs involving one or a few genes). These distributions are quite similar to one another. Indeed, for 3DGD < 5 (encompassing 98% of the gene pairs), the distributions are difficult to distinguish, and the only distinguishing feature for 3DGD = 5 is due to effects of just a few genes (see figure legend). Differences between the means of the distributions (shown graphically in the plot) are quite small compared to the variation of CUFS within each 3D distance category. Clearly CUFS is not strongly associated with 3D distance.

      The weakness of the correlations is in no way negated by the fact that the authors’ binning procedure yields high values. Most correlation coefficients will be inflated by this procedure, including the prototypical coefficients calculated by Galton and Pearson. For samples drawn from a bivariate normal distribution with a correlation coefficient of just 0.03, this procedure, with the relevant bin and sample sizes, yields Spearman’s correlation coefficients greater than 0.9. It would be absurd to describe such variables as strongly correlated, and reporting a Spearman’s correlation of >0.9 would be grossly misleading.

      Large data sets can give us the statistical power to detect very weak correlations, revealing what has been called the “crud factor”: that “everything correlates to some extent with everything else.”[4] Weak correlations are easily produced in the absence of a direct or otherwise interesting connection between the variables. Weak correlations are sometimes enlightening, but exaggerating their strength only obscures.

      References

      1. Triola, M. F. Elementary Statistics. Addison-Wesley, Reading, MA (1992)

      2. Kenny, P. W. & Montanari C. A. Inflation of correlation in the pursuit of drug-likeness. J. Comput. Aided Mol. Des. 27:1-13 (2013).

      3. Brand, A. & Bradley M. T. More voodoo correlations: when average-based measures inflate correlations. The Journal of General Psychology. 139(4):260-272 (2012).

      4. Meehl, P. E. Why summaries of research on psychological theories are often uninterpretable. Psychological Reports. 66:195-244 (1990).


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    1. On 2015 Jan 22, Yuriy Pankratov commented:

      This discussion could be more enlightening and even reach a consensus of some sort if our respected opponents, instead of making ungrounded accusations and avoiding inconvenient facts, tried to address the most serious issues, raised in our comments at PubMed Common and JNS website. These issues include: stark contradiction between the EGFP and LacZ expression phenotypes shown in Fujita et al. and data shown in previous publications (all of which went through rigorous peer review by the way); lack of direct evidence of notable impairment of synaptic transmission in dnSNARE mice and existence of clear evidence of the opposite; large pool of evidence supporting physiological role of astroglial exocytosis which does not rely on the dnSNARE mice at all. Neither paper itself nor Authors’ responses to comments (which basically repeats what was said in the article) address these issues.

      Still, we think that some consensus might be found. Before going to that point, we would like to clarify points raised by our opponents in their last post. 1) For the sake of unbiased discussion, citing one paper showing a lack of VAMP2 expression in astrocytes (Schubert et al.2011) one might mention at least one paper from the large pool showing the opposite (Martineau et al 2013).

      More importantly, one should not swap between quantitative and “all-or-none” kind of reasoning to one’s convenience. If we assume that level of astrocytic expression of VAMP2 of tenth of that in neurons is low enough to make VAMP2 non important for function of astrocyte, than we have to assume the existence of certain level of expression below which dnSNARE transgene will not significantly affect neuronal function as compared to astrocytes. OK, it may be not tenth but hundredth fraction, dose not matter.

      We thankful to our opponents for bringing up an example of tetanus and botulinum toxins. Even theses deadliest toxins act in dose-dependent manner. Both on the levels of whole organism and single presynaptic terminals, smaller doses of these toxins (as compared to LD50 and IC50) have milder effects. So, it is very likely that effects of dnSNARE expression are dose-dependent (if not to believe in homeopathy, of course).

      The same is applicable to the action of doxycycline, which is also dose-dependent. So one could not expect 100% inhibition of transgenes, especially at oral administration of Dox. To answer first part of opponents comment 2), the Figure 1O-R from Halassa et al. shows efficient, but incomplete suppression by Dox, rather than “leaky” EGFP expression. To what extent the same is applicable to Fig.2C of Fujita et al, let the reader to decide. Of course, non-complete suppression by Dox is a downside of tetO/tetA system but this can be easily remedied by comparing On-Dox and Off-Dox data.

      2) Theoretically speaking, concern that “neurons express the dnSNARE transgene at all “ may be applicable to any glia-specific transgenic mice. One could not a priori expect an absolute specificity of expression of neuronal and glial genes, the data of Cahoy et al. 2008 are the good illustration. This, rather philosophical, question goes far beyond the current discussion. There is no molecular genetic tool to ensure 100% glial specificity. On practice, one could only expect to obtain a negligible (again, in relative sense) level of neuronal transgene expression and verify the lack of significant impact on neuronal function.

      3) Regarding the putative “dramatic and unpredictable “ effects of neuronal dnSNARE expression, the TeNTx and BoNT give a good indication of what to expect. However, dnSNARE mice do not show any notable deficit of motor or respiratory function. On a level of synapses, there was no evidence of any significant decrease (not saying about complete inhibition) of vesicular release of main neurotransmitters (Pascual et al. 2005; Lalo et al. 2014). On contrary, our data show an impairment of signals triggered by activation of Ca2+-signalling selectively in astrocytes (Lalo et al. 2014; Rasooli-Nejad et al. 2014). Let it to the reader to decide, to what extent available functional data support the opponents’ notion that “synaptic transmission may directly be suppressed by dnSNARE expression in neurons “ and that “Even very low levels of expression of dnSNARE in neurons invalidate any conclusion based on this transgenic mouse “.

      One might argue that dnSNARE transgene could be expressed only in the certain subset of neurons or in some specific brain region thus strongly affecting some specific function rather than causing general, milder, functional deficit. However, this is unlikely for the supposed basal leakiness of the tet-off system and further experiments would be required to identify such regions/neuronal subsets.

      4) Addressing the second half of the point 2) – One can only wonder why, in 2012, already knowing that their results contradict to data presented by that time by several studies, our respected opponents did not contact authors of those publications to request mice from them? Again, one might only wonder why PCR data generated from 2 batches of mice have sample size of n = 3 – 4 (meaning 1-2 tissues per batch) ?

      5) Regarding the intrinsic limitations of dnSNARE mice, anyone working with them is aware of fact that EGFP, LacZ, and dnSNARE genes were inserted independently. However, their expression is controlled by the same factors so their expression probabilities depend on the same set of parameters and therefore are not truly independent, from mathematical point of view. The correlation in expression of these transgenes is supported by the co-inheritance. Furthermore, data of Halassa et al. show that 97% of cells expressing the dnSNARE, also express EGFP. We would like to emphasize that the opposite - the presence of true mosaic expression pattern in dnSNARE mice, i.e. existence of number of individual cells expressing dnSNARE and not expressing EGFP and number of EGFP-only cells, has not be shown so far; Fig.3 from Fujita et. al 2014 does not show this either.

      Thus, even assuming the leakiness of the “tet-off” system, one might expect probability of EGFP expression to be of the same order of magnitude as that of dnSNARE, this is also agrees with data of Fujita et al. So, in case of absence of EGFP expression in a large population of neurons, the presence of even small fraction of neurons expressing dnSNARE is very unlikely. From mathematical point of view, the probability of certain population of neurons to express only dnSNARE will fall exponentially with the expected size of population.

      Finally, one could hardly deny the large difference in the phenotype of the cohort of dnSNARE mice, described by Fujita et al. and the cohort of mice used by other groups. The point of some consensus could be that in some, still unidentified conditions, the tetA/tetO system may suddenly became leaky, causing some level of expression GFAP-driven transgenes dnSNARE, EGFP and lacZ genes in neurons. So, in experiments with dnSNARE mice extra care should be done to verify the lack of neuronal dnSNARE expression. This can be done by showing the absence of surrogate reporters EGFP or lacZ in neuronal populations of interest combined with electrophysiological data showing the lack of deficit of synaptic neurotransmitter release. This could be a good practice for any glia-specific inducible transgene.


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    2. On 2015 Jan 13, Maiken Nedergaard commented:

      With all respect to the commentator, the misleading posted arguments and evident lack of insight into the biology and construction of the dnSNARE mice underscores the danger of such unsolicited and unreviewed posting, not subject to peer review. That said, we have clarified several points below, and will leave it to the reader to evaluate our data as published in Fujita et al., J Neurosci, 2014 and to form an unbiased opinion.

      1) Our immunolabeling data does not show that astrocytes fail to express VAMP2, nor did we ever make such a claim. Rather, our analysis documents that astrocytes express VAMP2 at much lower levels than neurons, both in vitro and in vivo. Besides our own data, this notion is supported by independent sets of data – transcriptional analysis showed that astrocytic expression of Vamp2 is a tenth that of neurons (Cahoy JD, 2008), while an immunohistochemical analysis showing that VAMP2 is enriched in presynaptic terminals, and is not detectable in astrocytes (Schubert V, 2011).

      The dnSNARE mice express the 3 genes (EGFP, LacZ, and dnSNARE) independently of one another; their expression cassettes were injected in the oocyte as separate genes. Thus, a mosaic pattern of expression is to be expected, and that is what Fig. 3 documents. We certainly agree that astrocytes express all 3 transgenes at higher levels than neurons do; we documented precisely this point in Fig. 2D. However, the key element of our study is to demonstrate that leaky neuronal expression, and hence low levels of dnSNARE expression in neurons, may significantly impact synaptic transmission, since VAMP2 is essential for the fusion of synaptic vesicles with the presynaptic membrane.

      Incidentally, the best example of the damage that may be wrought by any neuronal expression of dnSNARE is the acute mortality associated with nanogram quantities of botulinum toxin. Botulinum toxin’s actions are analogous to those of dnSNARE; the functional consequences of both derive from the necessity of the SNARE complex to the release of synaptic vesicles.

      2) We will leave it to the reader to evaluate the immunohistochemical analysis, but will note that the leaky expression of EGFP was also displayed in Halassa MM, 2009, Fig. 1O-R. Unfortunately, EGFP expression has no predictive value for expression of the dnSNARE transcript, since as noted, the genes are independently expressed. We received the dnSNARE mice from Dr. McCarthy, rather than one of the groups using the mice, because Dr. McCarthy made the dnSNARE mice. We have analyzed two independent shipments (received in 2007 and 2012) and identified neuronal expression of EGFP in both sets of mice.

      3) This comment reveals a basic misunderstanding of the inherent limitation of the dnSNARE mice. Direct inhibition of vesicular fusion in neurons is expected to interfere - in dramatic and unpredictable ways - with neuronal activity in the intact animals. It is not a matter of the relative expression of dnSNARE expression in neurons versus astrocytes. Even very low levels of expression of dnSNARE in neurons invalidate any conclusion based on this transgenic mouse. Moreover, we document in Fig. 2H that neurons express the dnSNARE transgene in the presence of doxycycline, and that transgene expression is increased after removal of doxycycline. In other words, the expression of the dnSNARE transgene is also controlled by doxycycline in neurons.

      4) Again, it is not a matter of the relative leakiness of dnSNARE expression in neurons. The fact that neurons express the dnSNARE transgene at all is the fundamental concern. Interfering with synaptic release is one of the most powerful manipulations that may be executed upon a neuronal network.

      5) Once again, the point of our study is not to show predominant neuronal dnSNARE expression. We document that cortical neurons do express the dnSNARE transgene, and that the expression of dnSNARE in neurons is regulated by doxycycline. These observations invalidate the use of dnSNARE transgenic mice in the study of neuroglia signaling: It is not possible to attribute change in neuronal activity to gliotransmitter release, since synaptic transmission may directly be suppressed by dnSNARE expression in neurons.

      6) Unfortunately, exchange speaks as much to the deficiencies of the PubMed Comment mechanism as to the self-defensive but ultimately unsupportable arguments of the commentator, as it invites a Reddit-like forum, in which informed and uniformed commentary are admixed into an unenlightening whole.

      Commented by Maiken Nedergaard, Takumi Fujita, Michael J. Chen


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    3. On 2015 Jan 05, Yuriy Pankratov commented:

      Article by Fujita et al. aims to put under question an importance of SNARE-dependent vesicular gliotransmission basing on their observation of “widespread “ neuronal expression of dnSNARE transgene. However, there are several inconsistences and misinterpretations in the data which seriously undermines the main conclusion on the paper.

      1) The immunocitochemical analysis (Figure 3A-D), which is supposed to show “widespread neuronal expression” of b-Gal and EGFP in dnSNARE mice actually gives merely an anecdotal evidence of their expression in minor population of neurons. Neither Figure 3 nor the description of results in the text provides any statistical data. In Fig.3A, white arrows are used to draw attention to the correlation of green VAMP2- and orange MAP2-staining in neurons which is a trivial result. However, careful inspection of these images reveals a number of green puncta not associated with orange staining which might be as well located in astrocytes. To rule this out, the quantitative data on correlation of VAMP2 with neuronal and glial markers are essential. The lack of VAMP2 staining in cultured astrocytes (Fig3) is in controversy with data of Pascual et al (2005). This fast was ignored by the Authors, as well as other evidences of VAMP2 expression in astrocytes (Parpura 1995, Maienschein 1999, Montana 2004, Martineau 2013).

      Similarly, careful inspection of images shown in Fig 3C,D shows that most of cells stained for NeuN do not show b-Gal signal for and EGFP fluorescence; only few cells show co-localisation of the tetO transgenes with neuronal marker. As it is, Fig.3 does not strongly support the conclusion of “widespread neuronal expression” and I have a doubt that quantitative analysis of correlation of b-Gal and EGFP signal with neuronal and glial markers will show predominance of their neuronal localisation. Authors themselves admit this implicitly, saying about strong EGFP expression in astrocytes and “low to moderate level” of EGFP expression in neurons (p.16597). Also, there is no reproducibility in the shape of cells stained for NeuN across the four columns in Fig.3C which might be an indication for the lack of specificity of antibodies.

      2) Talking about reproducibility, the immunocytochemistry and EFGP data in Fig.3 are in striking controversy with previous data shown by the P. Haydon’s group (Pascual 2005; Halassa e2009, Lalo 2014). We observed more than hundred of brain slices from dn-SNARE mice and dnSNARE-negative littermates and did not see any neuronal EGFP fluorescence like that one shown in Fig3. Also, the pattern on astroglial EGFP-signals shown in Figure 3C (mainly diffuse staining with rare bright somata) is different from previous reports, showing numerous bright somata with bright bushy processes. Comparing EGFP-images shown by Fujita et al. with previous reports, one might wonder whether these images were obtained in the same strain of mice at all. The possible explanations of the discrepancy and reported “leakiness” of GFAP-tTA promoter might be a founder effect in the cohort of mice used by Fujita et al. or influence of epigenetic factors. It was reported that level of DNA methylation can strongly affect the GFAP expression in neurons and astrocytes (Barresi 1999; Hatada PLoS One 2008; Takizawa Dev Cell 2001). Again, one might only wonder why Authors imported the dn-SNARE mice not from P. Haydon’s lab, but from Ken McCarthy’s who did not publish any major paper on dn-SNAREs apart from his earlier collaboration with P. Haydon.

      3) Analysis of basal leakiness of tet-Off system in Figure 3E may be misleading since qPCR data on transgenes expression are compared to the “clear” wild-type mice. No wonder that such comparison showed large, statistically significant difference. However, in physiological and behavioural experiments data recorded in dnSNARE Dox-Off mice are usually compared to the data from dnSNARE Dox-On mice or from the dnSNARE-negative littermates (Pascual et al. 2005; Halassa et al. 2009; Lalo et al. 2014). When compared in such way, the data in Fig.3E shows a different picture. Firstly, expression of dnSNARE transgene in Dox-On and GFAP-tTA/dnSNARE negative mice is much less than in Dox-Off. Secondly, expression of dnSNARE transgene in GFAP-tTA/dnSNARE negative mice is much less than Lac-Z and EGFP transgenes. Also, one can see from Fig.3C that characteristic astrocytic EGFP staining patterns disappear in the Dox-On and GFAP-tTA/dnSNARE negative mice. Combined, these data suggest that putative leakiness of tet-Off system under GFAP promoter affects mainly basal neuronal expression of transgenes whereas level of glial dnSNARE expression is much less in non-dnSNARE mice as compared to dnSNARE-Dox Off. So, even if GFAP promoter can be leaky, it can be mitigated by using the dnSNARE-negative littermates as a control.

      4) Putting aside putative explanations of problems with cohort of dn-SNARE mice used by Authors, the data shown in Figures 2 and 3 are in some agreement that neuronal dnSNARE expression does not prevail even in that particular cohort. As shown in Fig.2E and stated in the Discussion, the cortical neuronal dn-SNARE expression reaches only 32% of glial level in 8-day old mice which is hardly big news since it is widely known that GFAP promoter can also be active in neurons as this stage of development. Furthermore, level of neuronal dn-SNARE expression was much less in the adult age. Although Authors do not provide a direct comparison of neuronal and glial fractions, estimation could be done using neuronal marker Rbfox3 as a reference. Comparing Figs.2 G-G, one could estimate the fraction of dn-SNARE expressing neurons as 1/16, i.e 8%. Even taking 20% as an “optimistic” estimate, one cannot draw a definitive conclusion about predominantly neuronal expression of dn-SNARE transgene in the adult mice without direct evidence of impairment of neurotransmitter release. Such evidence could be provided by demonstrating the significant decrease in the frequency of mIPSCs or mEPSCs or at least the decrease in the baseline fEPSPs in the neurons of off-DOX mice.

      5) So, the paper lacks crucial evidence of “the profound suppression of synaptic transmission in Off-Dox dnSNARE mice”. In contrast, previous works on dnSNARE mice showed up-regulation of excitatory synaptic transmission in hippocampus (Pascual 2005) and up-regulation of inhibitory synaptic transmission in the neocortex (Lalo 2014) of dnSNARE mice. Thus, the dnSNARE mice (at least used in the previous work) do not have a major deficit in presynaptic release of neurotransmitters, strongly arguing against abundant neuronal dnSNARE expression. This inconvenient fact was ignored.

      Authors show that removal of Dox induces the suppression of the EEG signal amplitude but attribute this effect to the neuronal expression of dnSNARE. Since Authors do no provide a convincing evidence of predominant dnSNARE expression in neurons as compared to glia (and show some evidence of the opposite) and do not provide any direct evidence of impaired synaptic signalling in neurons, this conclusion is unconvincing if not incorrect. One could argue that suppression of the EEG signal might be due to profound astrocytic dnSNARE expression, which was also observed in the present paper, causing an impairment of gliotransmitter release and changes in glial modulation of synaptic transmission. Actually, the up-regulation of GABAergic synaptic transmission, that we observed in dnSNARE mice (Lalo 2014) is an good agreement with this hypothesis.

      6) Lastly, I would like to stress that in the former article we provide a several lines of evidence of exocytotic gliotransmission which cannot be affected by putative neuronal expression of dnSNARE transgene at all, in particular “sniffer-cell” detection of ATP release from isolated astrocytes and perfusion of individual astrocytes in situ


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    1. On 2015 Feb 11, Radboudumc Psycho-Oncology Journal Club commented:

      A well-written, very informative and interesting paper with good clinical value. We believe it’s important to overcome barriers to accepting psychosocial services; not only for distress but other mental health problems as well. During the plenary discussion of this paper, our Journal Club generated the following comments:

      1) 3070 patients completed the QUICATOUCH assessment of whom 10% scored above the threshold for distress (n = 310). We know from literature that psychological distress affects around 30% of all cancer survivors*. This percentage is substantially higher than the 10% found in current sample. We are wondering if there’s an explanation for this finding.

      2) In the results section, table 1. Four of the big five cancer types (and Lymphoma are mentioned as seperate categories, complemented by a category named “other”. Because this “other” category is the largest one in actual number of patients, it would be interesting to know which cancer types it represents.

      3) In the results section, we believe that the percentages for ‘Prefer to manage myself’, as portrayed in figure 1, do not match with the percentages mentioned in text. The figure displays a higher % of patients with a self-management preference for distress score 8-10 (53%) than distress score 4-5 (43%). In text, it’s the other way round.

      *Mehnert A, 2014,Mitchell AJ, 2007,Zabora J, 2001


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    1. On 2015 Feb 15, William Grant commented:

      The effect of diet on risk of Alzheimer's disease is very strong; vitamin D also reduces risk

      The paper by Deckers and colleagues used the Delphi consensus approach to rank the target risk factors for dementia [1]. Diet was ranked 6th out of 11 factors in the Delphi ranking round 2, behind depression, diabetes, cognitive ability, physical activity, and midlife hypertension.

      Ref. 1 relied primarily on prospective observational studies. While such studies are valuable, they are not the only way to assess risk. Another way is through ecological studies, either geographical or temporal. The first study to identify diet as an important risk factor for Alzheimer's disease was a multi-country ecological study [2]. It was discussed in two subsequent papers [3,4]. The most dramatic application of the ecological approach to studying the effect of diet on risk of Alzheimer's disease was in analyzing trends of Alzheimer's disease rates in Japan. The increase in Alzheimer's disease rates for elderly people in Japan from 1% in 1985 to 7% in 2008 was attributed to the nutrition transition from the traditional Japanese diet to the Western diet [5]. In addition, dietary advanced glycation end products from food cooked at high temperatures or aged as in hard cheese have been identified as an important risk factor for Alzheimer's disease [6, 7]. Diet is also a well known risk factor for diabetes.

      A factor not mentioned but one that is gaining acceptance is low 25-hydroxyvitamin D [25(OH)D] concentrations [8]. Low 25(OH)D concentrations have been reported as a risk factor for Alzheimer's disease and dementia [9], diabetes mellitus [10], and cognitive dysfunction [11].

      References 1. Deckers K, van Boxtel MP, Schiepers OJ, de Vugt M, Muñoz Sánchez JL, Anstey KJ, Brayne C, Dartigues JF, Engedal K, Kivipelto M, Ritchie K, Starr JM, Yaffe K, Irving K, Verhey FR, Köhler S. Target risk factors for dementia prevention: a systematic review and Delphi consensus study on the evidence from observational studies. Int J Geriatr Psychiatry. 2015;30(3):234-46. 2. Grant WB. Dietary links to Alzheimer's disease. Alz Dis Rev. 1997;2:42-55. http://www.sunarc.org/JAD97.pdf) 3. Grant WB. Dietary links to Alzheimer’s disease: 1999 update. J Alz Dis. 1999;1197-201. 4. Grant WB, Campbell A, Itzhaki RF, Savory J, The significance of environmental factors in the etiology of Alzheimer’s disease. J Alz Dis. 2002;4:179-89. 5. Grant WB. Trends in diet and Alzheimer’s disease during the nutrition transition in Japan and developing countries. J Alzheimers Dis. 2014;38(3):611-20. 6. Cai W, Uribarri J, Zhu L, Chen X, Swamy S, Zhao Z, Grosjean F, Simonaro C, Kuchel GA, Schnaider-Beeri M, Woodward M, Striker GE, Vlassara H. Oral glycotoxins are a modifiable cause of dementia and the metabolic syndrome in mice and humans. Proc Natl Acad Sci U S A. 2014;111:4940-5. 7. Perrone L, Grant WB. Observational and ecological studies of dietary advanced glycation end products in national diets and Alzheimer’s disease incidence and prevalence. J Alzheimers Dis. 2015 Jan 29. [Epub ahead of print] 8. Grant WB. Does vitamin D reduce the risk of dementia? J Alzheimers Dis. 2009;17(1):151-9. 9. Littlejohns TJ, Henley WE, Lang IA, Annweiler C, Beauchet O, Chaves PH, Fried L, Kestenbaum BR, Kuller LH, Langa KM, Lopez OL, Kos K, Soni M, Llewellyn DJ. Vitamin D and the risk of dementia and Alzheimer disease. Neurology. 2014;83(10):920-8. 10. Song Y, Wang L, Pittas AG, Del Gobbo LC, Zhang C, Manson JE, Hu FB. Blood 25-hydroxy vitamin D levels and incident type 2 diabetes: a meta-analysis of prospective studies. Diabetes Care. 2013;36(5):1422-8. 11. Annweiler C, Dursun E, Féron F, Gezen-Ak D, Kalueff AV, Littlejohns T, Llewellyn DJ, Millet P, Scott T, Tucker KL, Yilmazer S, Beauchet O. 'Vitamin D and cognition in older adults': updated international recommendations. J Intern Med. 2015;277(1):45-57.


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    1. On 2015 Jan 11, Donald Forsdyke commented:

      CONTINUING SUPPORT FOR GRANTHAM'S GENOME HYPOTHESIS

      Richard Grantham (1980), after examination of a mere 160 short sequences, proposed his ‘genome hypothesis.’ For nucleic acids he envisaged ‘manifold constraints and adaptations, of both structural and functional natures.’ These ‘could exist, independently of protein coding.’ Thus, there was ‘protein-independent molecular evolution of a non-neutral character.’ The distinctive ‘coding strategy of an organism’ was ‘at the heart of the problem of molecular evolution,’ and was likely to prove of fundamental importance for ‘speciation and systematics in general’ (Grantham et al. 1986).

      These observations won extensive support when thousands of much longer sequences became available, even though many were incomplete (Forsdyke and Mortimer 2000; Mortimer and Forsdyke 2003; Lee et al. 2004). The data, consistent with the early base compositional studies of Chargaff, Sueoka and Szybalski, are now further affirmed by this comprehensive new work involving thousands of entirely complete sequences (Goncearenco and Berezovsky 2014).

      However, while there is little disagreement on data and the need for evolutionary trade-offs (‘mutual adjustment of the nucleotide and amino acid compositions’), readers should note that there remains disagreement over interpretations (see my comments on a previous paper and my textbook; Zeldovich et al. 2007, Forsdyke 2011). Readers should also note that the present text (p. 3) has proline (P) listed in both the high GC% saturation group and the low GC% saturation group. In error, phenylalanine (F) was replaced by P in the latter. The GC% low and medium groups have amino acids listed in order of increasing codon GC% saturation, but the GC% high group has amino acids listed (p. 3) in decreasing order of codon GC% saturation (see Fig. S3). And it is puzzling that Figures 1a and 1b appear the same, with just axis labels interchanged, yet some points seem incorrectly interchanged. The rectilinear interpretations of obvious curvilinear relationships (Figs. 8, S9) are also problematic, as noted by Reviewer 2.

      The notion that aspartate and glutamate (with purine-rich codons GAY and GAR) ‘cannot be used for the efficient tuning of the nucleotide composition,’ does not hold for the tuning of AG%. Furthermore, it should be noted that as GC% increases, the decline of A and T does not affect both bases equally. While G% and T% tend to remain constant, C increases at the expense of A. Likewise, when GC% decreases, A increases at the expense of C (Mortimer and Forsdyke 2003). This A-for-C transversional trading, most evident at extreme GC% values (Fig. S10), should decrease the probabilities of G-quadruplexes and thymine dimers. Finally, noting for example the high AG% in thermophiles, it may be premature to conclude that tradeoffs are a ‘purely compositional phenomenon, linking the realms of nucleic and amino acids in prokaryotes regardless of their life styles, environments, and phylogeny.’ Grantham’s admonition regarding speciation and systematics should not go unheeded.

      Forsdyke DR: Evolutionary Bioinformatics. 2nd edition. New York: Springer, 2011.

      Forsdyke DR, Mortimer JR: Chargaff’s legacy. Gene 2000, 261:127-137.Forsdyke DR, 2000

      Goncearenco A, Berezovsky IN: The fundamental trade-off in genomes and proteomes of prokaryotes established by the genetic code, codon entropy, and physics of nucleic acids and proteins. Biology Direct 2014, 9:29.Goncearenco A, 2014

      Grantham R: Workings of the genetic code. Trends Biochem Sci 1980, 5:327-331.

      Grantham R, Perrin P, Mouchiroud D: Patterns in codon usage of different kinds of species. Oxford Surv Evol Biol 1986, 3:48-81.

      Lee S-J, Mortimer JR, Forsdyke DR: Genomic conflict settled in favour of the species rather than of the gene at extreme GC% values. Applied Bioinformatics 2004, 3:219-228.Lee SJ, 2004

      Mortimer JR, Forsdyke DR: Comparison of responses by bacteriophage and bacteria to pressures on the base composition of open reading frames. Applied Bioinformatics 2003, 2:47-62.Mortimer JR, 2003

      Zeldovich KB, Berezovsky IN, Shakhnovich EI: Protein and DNA sequence determinants of thermophilic adaptation. PLoS Comput Biol 2007, 3(1):e5.Zeldovich KB, 2007


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    1. On 2015 Mar 29, Geriatric Medicine Journal Club commented:

      The full version of study of the American Geriatrics Society Clinical Practice Guideline for Postoperative Delirium in Older Adults was reviewed at the March 2015 Geriatric Medicine Journal Club (follow #GeriMedJC on Twitter). The full discussion can be found at: http://gerimedjc.blogspot.com/2015/03/gerimedjc-march-27-2015.html?spref=tw This is an important document as surgical specialists identified delirium as “essential" more than any other topic in the care of older adults. While the #GeriMedJC discussion noted there were no real surprises in this data synthesis, hopefully this guideline will serve to fill a knowledge gap.


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    1. On 2014 Dec 13, David Keller commented:

      The grandfathered internists had 20% more experience in practice than the MOC'ed internists

      The "grandfathered" internists in this study were certified in 1989, while the "MOC'ed" internists (those forced to undergo Maintenance of Certification) were certified in 1991. The study was conducted in 2001, so the grandfathered internists had 12 years in practice, while the MOC'ed internists had only 10 years in practice. The difference of 20 percent more practice experience could account for much of the difference between the two groups; for example, the fact that the more experienced internists spent more money on patient care might reflect their increased experience in billing Medicare and insurance companies, which is knowledge not taught during the MOC process; rather, skill at billing is acquired through years in practice.


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    1. On 2015 Jan 20, Donald Forsdyke commented:

      HYPOTHESES OF SPECIATION As hinted at by one of the reviewers, hypotheses on the initiation of speciation are broadly categorized as genic and chromosomal (Nevo, 2012). The possibility that their intriguing observations on putatively sterile hybrids between certain mouse subspecies might be explained in chromosomal (non-genic) terms is not considered by Turner and Harr. Yet, from studies of hybrids of the same subspecies, Bhattacharyya et al. (2013; 2014) infer that “meiotic asynapsis of heterospecific homologous chromosomes is the primary mechanistic basis of hybrid sterility.” This indicates a role for “a fast-evolving subset of the noncoding genomic sequence important for chromosome pairing and synapsis.” Thus, any observed genic differences would be secondary to this (Page and Orr-Weaver, 1997).

      Furthermore, it is incorrectly implied by Turner and Harr that the work of Bateson (1909) supports the genic viewpoint to which the names of Dobzhansky and Muller are attached (“DM incompatibilities”). This is not a minor point, since Bateson consistently favored a non-genic viewpoint that is today best equated with the chromosomal hypothesis (Nei and Nozawa, 2011; Forsdyke, 2011).

      Bhattacharyya T, Gregorova S, Mihola O, Anger M, Sebestova J, Denny P, Simecek P, Forejt J. 2013. Mechanistic basis of infertility of mouse intersubspecific hybrids. Proceedings of the National Academy of Sciences, U S A 110: E468–477. doi:10.1073/pnas.1219126110.

      Bhattacharyya T, Reifova R, Gregorova S, Simecek P, Gergelits V, Mistrik M, Martincova I, Pialek J, Forejt J. 2014. X chromosome control of meiotic chromosome synapsis in mouse inter-subspecific hybrids. PLoS Genetics 10: e1004088. doi:10.1371/journal.pgen.1004088

      Forsdyke DR. 2011. The ‘B’ in BDM. William Bateson did not advocate a genic speciation theory. Heredity 106:202. doi:10.1038/hdy.2010.15.

      Nei M, Nozawa M. 2011. Roles of mutation and selection in speciation: from Hugo de Vries to the modern genomic era. Genome Biology and Evolution 3,812–829. doi:10.1093/gbe/evr028.

      Nevo E. 2012. Speciation: chromosomal mechanisms. In: eLS. Chichester: John Wiley & Sons. doi: 10.1002/9780470015902.a0001757.pub3.

      Page AW, Orr-Weaver TL. 1997. Stopping and starting the meiotic cycle. Current Opinion in Genetics and Development 7:23–31. doi: 10.1016/S0959-437X(97)80105-0.


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    1. On 2016 Jun 29, Bill Noble commented:

      Hi Zhibin, thank you for your comment. Yes, as we describe on p. 1148 in the paragraph beginning "Our primary goal in this article ...", there are many methods described in the literature for obtaining approximately calibrated scores. These are variously referred to as E-values or p-values, though the precise semantics of any such score depends on the method used to generate it. One of the main points of our article is to introduce an independent method to help evaluate the calibration properties of these types of scores. For example, Figure 3 shows the calibration properties of the MS-GF+ E-value. --Bill Noble & Uri Keich


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    1. On 2014 Dec 11, David Keller commented:

      Congress gave health insurers the right to violate patient privacy - this must end

      Physicians insert “boilerplate text", defined as words which convey no meaningful medical information or insights, into their clinical notes mainly to satisfy documentation requirements imposed by the Medicare Evaluation and Management (E&M) Services Guide. Medicare and nearly all private health insurers adhere to the E&M Guide to determine their payments to physicians. These E&M service definitions largely dictate the format and content of physicians’ progress notes.

      There is a natural tension between physicians, who want to be paid in full for their efforts, and payers, who want to minimize payments to physicians. Payers enforce physician adherence to E&M documentation and billing regulations by hiring clerical employees called “coders” to audit patients’ clinical charts for documentation deficiencies. To avoid fines and prosecution, physician notes are usually generated first and foremost to fulfill the requirements of these coder audits, rather than the needs of their fellow clinicians.

      Coders determine whether a progress note meets the billing requirements mainly by checking how many elements of defined data are present. Most physicians are not completely familiar with the complex, confusing, and arcane E&M requirements, so they load up their notes with as much computer-generated boilerplate as they can, hoping it will include an overlooked element of data needed to satisfy a coder’s audit.

      This whole system must be discarded, or there can never be any hope of having progress notes that communicate clearly and concisely between clinicians. A quick and sure way to end this “tyranny of the coders” is for Congress to terminate the exemption granted to payers by the patient privacy laws, including HIPAA. This would eliminate inspection of the clinical chart by payers and their coders. Payers would no longer need battalions of coders, who could be relieved of their duties and retrained to perform more productive tasks.

      Payers should not be allowed to read, inspect, or audit patients’ clinical charts; this is a violation of patients’ medical privacy. It harms patients by causing physicians to spend more of their limited time generating progress notes, leaving less time for interacting with patients. Payers must verify physician billings in some way which does not violate the privacy of patient charts. Payments could be determined by the average amount of physician time required to treat the patient’s illnesses and manage their chronic conditions, as determined from the submitted diagnosis codes. Physicians could submit attestations for any required variations. In a world without E&M coding requirements, the clarity and efficiency of clinical documentation could be improved enormously, with more time for physicians to actually examine and treat patients.


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    1. On 2014 Dec 12, David Keller commented:

      Parkinsonian constipation & altered gut microbiota: suggestions for further study

      It has long been known that constipation due to autonomic dysfunction is an early pre-motor finding in Parkinson disease (PD). Other bowel motility disorders have been causally linked with alterations in gut flora; for example, opioid-induced constipation is a known risk factor for C. Difficile overgrowth (1,2), which in turn can cause diarrhea. If Parkinsonian constipation promotes changes in gut flora, it is reasonable to ask whether these changes in gut flora might alter the course of PD itself.

      Do toxins produced by gut microbes contribute to CNS neurodegeneration in susceptible individuals? The serum levels of these toxins should be tracked in a study designed to measure their effects in PD. If overgrowth of certain toxigenic bacterial species appears to cause accelerated neurodegeneration, then treatment with antibiotics or probiotics (or both) should be tested in selected individuals, in an attempt to slow the progression of their PD.

      References

      1: Keller DL. Opioid use and clostridium difficile infection. Am J Med. 2013 Apr;126(4):e13. doi: 10.1016/j.amjmed.2012.08.024. PubMed PMID: 23507210.

      2: Mora AL, Salazar M, Pablo-Caeiro J, Frost CP, Yadav Y, DuPont HL, Garey KW. Moderate to high use of opioid analgesics are associated with an increased risk of Clostridium difficile infection. Am J Med Sci. 2012 Apr;343(4):277-80. doi: 10.1097/MAJ.0b013e31822f42eb. PubMed PMID: 21934595.


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    1. On 2017 Mar 23, University of Kansas School of Nursing Journal Club commented:

      Team Members: Jason Tracy, Abigail Spare, Julia Damman, Laura Thompson, Sophie Bono, Maeve Markey. [Class of 2017]

      Background

      In our class, we took time to study shared governance in acute care organizations and looked at the importance of shared governance in regards to all nursing positions. This article not only touches on the importance of shared governance, but also explores the processes needed to help direct patient care nurses transition their knowledge, skills, and attitudes into the leadership role that would facilitate shared governance. Our team was especially interested in the idea of shared governance, and liked how this particular article discussed an intervention to increase shared governance by empowering nurses with leadership. This is an interesting, practical intervention that could be implemented with nurses.

      Methods

      This was a descriptive qualitative study that took place at a university medical center hospital with 300 adult beds in southeastern U.S. Through partnership, the CNO and CON faculty developed a Frontline Innovations (FI) group that help mentor frontline nurses with leadership skills, problem solving strategies, and evidence based to fix identified operational failures. The group included 12 frontline nurses from 4 different medical surgical units chosen by the CNO based on their leadership potential. Frontline nurses are extremely important to include in change process because they have direct impact to patients outcomes.

      Interviews were conducted to reveal the steps of process improvement, and analysis of interviews determine recurring themes which were divided into process and outcome measures describing staff, administration, and faculty interaction. Engagement was identified as a component of the process theme and was observed through both verbal and nonverbal communication with the CNO, as well as focused role playing activities with interprofessional groups. The nurses that engaged in these group activities were then responsible for sharing what they learned with their peers on the unit (Dearmon et al. 2015).

      The study ultimately affected nursing administration and executives as well because of their influence in the structures and processes of various units. This influence carried over to the care delivery of frontline nurses give. Shared governance distributes power, resources, and information as equally as possible, so it is important that both administration and frontline nurses work together (Dearmon et al. 2015).

      Findings

      Outcome measures included collaboration, empowerment, confidence, and lifelong learning. Collaboration was found to be important for the creation of the organization’s new shared governance model. It allowed members to work together to achieve a common goal, strengthen group morale, and improve the credibility of decisions making process. Nurses began to feel empowered when they felt their voices were heard by the CNO and changes were made. Nurses who were given the opportunity to visit other facilities that has shared governance model returned to their own organization feeling empowered to brought back shared governance model in their unit. In order to instill confidence that the new shared governance model would work for the organization, Frontline Innovations group members coached nurses through the new project and allowed them to use the process to see success for themselves (Dearmon et al. 2015).

      Creating the Frontline Innovations group proved to be an effective way to influence change at the bedside through the implementation of a shared governance model. All disciplines involved learned to trust each other and this transferred to practice, improving collaboration in patient care. Nurses became more enthusiastic about the care they provided because they felt their voices were being heard and thus began to realize they had the ability to change practice when gaps were seen. The transition from a culture of administrative decision-making to one of staff engagement and shared decision-making forged an organization with all members willing to take responsibility for workplace obstacles (Dearmon et al. 2015).

      Nursing Implications

      The healthcare industry continues to become more complex as new discoveries are made. As these complexities expand the nursing practice becomes more specialized, making it more difficult for the executives in charge to understand the needs of the individual environments. Only by including the nurses that work in direct patient care areas can executives get a full picture of the operations and needs of the units. The literature shows that although both executive and front line nurses desire to collaborate, there is a gap to be filled before this can occur. The literature shows that there are means by which this gap can be bridged by developing mentorship programs, from which front line nurses can gain the knowledge needed to participate in counsels that effect change within the organization. This also helps nurses find their voice and the desire to work independently with their executive mentors to make quality improvements within their units. The end result was better working relationships between the two groups and more productive initiatives in providing better patient care (Dearmon et al. 2015). This means the healthcare industry is able to provide more efficient services and better patient outcomes due to changes made by the people involved in doing the work. As new nurses getting ready to enter the healthcare system, it is reassuring to know that our point of view is just as important as that of a nurse executive. Stepping into a new organization, we bring a fresh set of eyes that can see things to which others have become accustomed to. Being able to affect change within an organization is an important factor when choosing a career, and this article helps support this initiative. The section that discussed nurses being able to work independently gave rise to the idea of working and improving within specific system. Individually both systems can do a certain amount of work, but without collaboration they can ultimately fail. However, this also requires leadership to be in place in both systems. This means that although the executive officers may be the faces of the organization, nurse leaders in each system are called to step up to the task of effecting change.

      If the literature is found to be valid and reliable, then many changes are sure to come. There is already a push for hospitals to obtain Magnet status. The evidence found in this article supports the Magnet program and the need for more nurses stepping into leadership roles. This may also change how nurses are integrated into an organization by mandating new employees to be trained in the organization's leadership development program. The end product would include more staff educated in how to effectively work within their unit’s structure and how their unit collaborates best with other units. This alone can provide a multitude of solutions to decrease expenses and the amount of waste, provide more efficient care, and increase employee morale.

      Reference

      Dearmon, V., Riley, H., Mestas, G., & Buckner, B. (2015). Bridge to shared governance: Developing leadership of frontline nurses. Nursing Administration Quarterly, 39(1), 69-77. doi: 10.1097/NAQ.0000000000000082


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    1. On 2015 Apr 02, University of Lausanne Genomics, Ecology and Evolution Journal Club commented:

      The article nicely highlights the need for a reference genome panel consisting of African variants and understanding African population history. This is a summary of the discussion at our journal club. Gurdasani et al. offer evidence for B the antu expansion, although the sample distribution came mostly from the coast rather then inside of the African continent where the Bantu expansion occurred. Moreover, the article lacks discussion of the gene flow effects other then the impact of Euroasian admixture on the differentiation among the African populations. It would be interesting to see are some effects due to allele surfing or allele fixation. In the article, the highest proportion of Euroasian ancestry is observed in the Ethiopian population. The authors hypothesize that Euroasian ancestry is responsible for the differentiation in African populations, rather than adaptation to selective forces. But, the highly differentiated SNPs between Euroasian and African populations showed evidence of differentiation within genes of malaria susceptibility and osmoregulation, which makes the previous statement imprecise. Also, the results of population admixture shows an overlap both in Euroasian and HG ancestry in East Africa without any further explanation of how it happened. The last part of the article is probably the most valuable one, since it shows the improvement of imputation accuracy of African populations variants by using different reference genome panel. Although finding the optimal array design for capturing most of African variation is admirable, in the current state of sequencing technology it might not be necessary anymore. A final remark is that the visualization of the results in extended and supplementary data was sometimes hard to decipher.


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    1. On 2014 Dec 04, Rafael Najmanovich commented:

      We predicted back in 2012 (Chartier M, 2012) as part of a large scale analysis of rare codon cluster that such clusters may play a role in molecular recognition whereby translational pauses in the nascent protein would permit its interaction with other proteins to permit intracellular targeting and membrane insertion. It is unfortunate that the authors were not aware of our publication.


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    1. On 2014 Dec 10, Jim Woodgett commented:

      There is no direct evidence in this paper that the effects of lithium on kidney function are specifically via GSK-3beta. The GSK-3alpha isoform, which was not investigated, is equally inhibited by this ion and the following statement is erroneous: "lithium, a selective inhibitor of GSK3β". As an aside, dominant negative GSK-3beta (kinase-dead), interferes with both GSK-3alpha and beta.


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    1. On 2015 Feb 06, Ryan Radecki commented:

      Post-publication commentary: "More Futility for Mechanical CPR"

      A few weeks ago we reported on the use of the LUCAS-2 for crushing the thorax, resulting in significant internal injuries. None of these injuries were judged to have contributed to any patient’s demise – but, still, concerning. This could be more forgivable if there were other advantages, say, survival.

      Unfortunately, yet again, mechanical CPR fails to demonstrate superiority....

      http://www.emlitofnote.com/2014/12/more-futility-for-mechanical-cpr.html


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    1. On 2015 Jan 22, Larry Parnell commented:

      This paper was my selection for Paper of the Week for 12-16 Jan 2015.

      We have it rather interesting to map onto the network described in this article (Fig 2) those genes carrying variants that associate with obesity anthropometrics. Some regions of the network are sparsely populated or entirely devoid of such obesity GWAS genes, while others have a great concentration of such genes.

      We were surprised not to see FTO or extracellular remodeling genes/proteins displayed in this network. The FTO/IRX3 locus has much evidence linking it to obesity. As adipose expands, much remodeling of the extracellular matrix takes place.


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    1. On 2015 Aug 10, NephJC - Nephrology Journal Club commented:

      This study was discussed on July 28 and 29th 2015 in the open online nephrology journal club, #NephJC, on twitter .

      Introductory explanatory comments, written by Matt Sparks, are available at the NephJC.

      There was a very lively discussion, which included about 50 participants, enriched by the active engagement by two of the authors, Ben Humphreys and Rafael Kramann, and was complete with many citations to related research articles.

      A transcript and a curated (i.e. Storified) version of the tweetchat are available from the NephJC website.

      The highlights of the tweetchat discussion were:

      • The study does help establish that Gli1+ perivascular ('pericytes') MSC-like cells are the source of ~70% of myofibroblasts after organ injury, and are key players in the subsequent fibrosis.

      • Successful/effective targeting of this pathway leads to less fibrosis in preservation of heart function after transverse aortic banding (a heart failure model), however substantial hurdles still exist in terms of delivering a potential therapeutic intervention to lessen fibrosis but ensuring the protective effects of fibrosis are not inhibited.

      • The authors' did remarkable work in leveraging elegant techniques such as lineage tracing, multiple organ injury models, parabiosis and diphtheria toxin/Gli1 knockout.

      Interested individuals can track and join in the conversation by following @NephJC or #NephJC, or visit the webpage at NephJC.com.


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    1. On 2016 Jul 01, Nicholas J L Brown commented:

      Our reanalysis of the data from the article by Vedhara et al. (2015) showed that their results are fragile and ambiguous and depend on (a) the inclusion or exclusion of two study participants missing values for one of the control variables and (b) the accumulation of statistical suppression effects in the regression analyses. See 10.1016/j.paid.2015.11.055.


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    1. On 2016 Aug 05, Zvi Herzig commented:

      Adding to Bates' comments below, here are some specific misrepresentations of the primary evidence by the Pisinger and Døssing review, relating to almost every major issue in e-cigarette toxicology (not an exhaustive list):

      • “Some studies found high maximum concentrations of total TSNA”, citing studies showing TSNAs 100-200 times below cigarette smoke levels [1-3].
      • “Exposure to formaldehyde was comparable with smoking", referring to a study calculating formaldehyde levels nine times below that from tobacco smoke [1].
      • “Propylene glycol has been found to exacerbate and/or induce multiple allergic symptoms in children”, citing a study stating that "apparently… outcomes were not driven by propylene glycol” [4].
      • “Values below the threshold limit don't necessarily protect against the health effect of 200–300 daily inhalations over decades”, referring to safety limits calculated for 8 hours exposures “day after day, over a working lifetime” [5].
      • “These metals appear on the U.S. Food and Drug Administration's 'Harmful and Potentially Harmful Chemicals' list”, referring to metals detected below levels acceptable to the FDA for chronic inhalation [6-8].

      [1] Goniewicz ML, Knysak J, Gawron M et al. Levels of selected carcinogens and toxicants in vapour from electronic cigarettes. Tob Control 2014

      [2] Kim HJ, Shin HS. Determination of tobacco-specific nitrosamines in replacement liquids of electronic cigarettes by liquid chromatography-tandem mass spectrometry. J Chromatogr A 2013

      [3] Farsalinos KE, Romagna G, Voudris V. Authors miss the opportunity to discuss important public health implications. J Chromatogr A 2013

      [4] Choi H, Schmidbauer N, Spengler J et al. Sources of propylene glycol and glycol ethers in air at home. Int J Environ Res Public Health 2010

      [5] ACGIH. Chemical Substances Introduction. acgih.org 2016. http://www.acgih.org/tlv-bei-guidelines/tlv-chemical-substances-introduction

      [6] Siegel M. Metals in Electronic Cigarette Vapor are Below USP Standards for Metals in Inhalation Medications. The Rest of the Story: Tobacco News Analysis and Commentary. 2013.http://tobaccoanalysis.blogspot.com/2013/04/metals-in-electronic-cigarette-vapor.html .

      [7] Farsalinos K. Metals and nanoparticles in e-cigarettes. 2013.http://www.ecigarette-research.com/web/index.php/2013-04-07-09-50-07/2013/89-metals-and-nanoparticles-i n-e-cigarettes-commentary.

      [8] Farsalinos K, Voudris V, Poulas K. Are Metals Emitted from Electronic Cigarettes a Reason for Health Concern? A Risk-Assessment Analysis of Currently Available Literature. International Journal of Environmental Research and Public Health 2015


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    2. On 2016 Aug 16, Clive Bates commented:

      Note: The focus on conflicts of interests (COI) received criticism both for exaggeration and for the tacit assumption that a COI declaration somehow invalidates the scientific merit of the work. See Kosmider L, 2016 Ideology versus evidence: Investigating the claim that the literature on e-cigarettes is undermined by material conflict of interest and the reply from the authors Pisinger C, 2016 Reading the conflict of interest statement is as important as reading the result section: Response to the letter by Dr. Kosmider.

      COI declaration is not intended as a form of self-invalidation, but for transparency. It is absurd to assert that it is as important as the substance of the work itself. COI tends to focus on conflicts arising from commercial interests, but many researchers in this field have undisclosed conflicts relating to funders, regulators, employers' prior policy positions, and their long-held beliefs. If these authors want to investigate COI (not the ostensible purpose of this work), then they should do it rigorously, and with a broader view of COI.


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    3. On 2016 Aug 05, Clive Bates commented:

      Despite the title, the review does not address the "health effects of electronic cigarettes". Or perhaps to the extent that it does, it does not find anything negative to report. This may explain the diversionary conclusion, which resorts to an argument about competing interests rather than a critique of actual scientific findings [see note appended below].

      It does, however, attempt to summarise various proxies for health effects but does this very poorly. Throughout the substance of the article, it fails to internalise the most basic concept in toxicology:

      "the dose makes the poison" (attributed to Paracelsus, 1538).

      The assessment of e-cigarette science by the Royal College of Physicians (London), Nicotine without smoke: tobacco harm reduction, 28 April 2016 included this review but passed over it in the following terms:

      Recent reviews of the health effects of toxins inhaled during normal use of e-cigarettes have expressed concerns over potential adverse effects based on the presence of these contaminants, but not their levels, which are generally the more important determinant of toxicity.

      The danger of a review that approaches toxicology in this way is that plays into public fears inspired by chemical names and may deter smokers, who are at well-established serious risk from high exposures to harmful agents, from switching to the much safer vapour products. In doing so, the careless framing of scientific findings can cause actual harm.

      In addition, such work provides a citable source for irresponsible activism, and so can entrench misunderstanding in regulatory bureaucracies like the WHO, FDA and European Commission - further amplifying the harm through ill-conceived regulation.

      For any future work, these authors or others should carefully distinguish between the following:

      • The detection of the presence of a hazardous agent in vapour, recognising a de minimis level for which there is no material concern - see Burstyn I, 2014 for an approach that adopts occupational exposures as a frame of reference.

      • Human exposure to a hazardous agent that may or may not present a risk to health recognising that magnitude of exposure and materiality matter. For an insight into how to approach this, see Farsalinos KE, 2014. These authors provide a good example in Table 3, showing e-cigarette nitrosamine exposure to be about 1,000 times lower than in cigarette smoke and comparable to the residual levels found in regulated medicinal NRT.

      • Observed damage to cells found in vitro following exposure to vapour that may have no bearing on human exposure or risk. See criticism of the extreme misinterpretation of one cell study finding in PubMed Commons on Yu V, 2016. This study provides a good example of what not to do.

      • Observed impacts in animal studies, which are rarely a reliable proxy for human experience - see discussion by the Laura and John Arnold Foundation of the weakness of animal studies: Why journalists should stop publishing mouse studies

      • The illusion of risks induced by operating vaping equipment in a way that no human user will ever experience other than momentarily. The Jensen RP, 2015 study on 'hidden formaldehyde' is a case in point and has been severely and appropriately criticised (Bates CD, 2015) for running equipment too hot and in 'dry puff' conditions, and then sensationalising the findings as if they showed a cancer risk, and suggesting these may be greater than for smoking.

      • Observed changes to the human body that are not necessarily an indication of harm to health. Nicotine and coffee both create changes to the cardiovascular system, but neither is a direct cause of material harm - see PubMed Commons review of Carnevale R, 2016.

      • Signs of immediate health gains when e-cigarettes are used as an alternative to smoking - for examples see Polosa R, 2015 and Polosa R, 2014 for examples of 'harm reversal' in chronic respiratory patients.

      Finally, given that almost all e-cigarette users are former or current smokers, then any attempt to provide useful information on e-cigarette risk should always use cigarette smoking and related risk as a point of reference, not only the risks compared to complete abstinence. To avoid this comparison is to miss the value of harm reduction as a strategy in tobacco control. There are many examples of this failure - to take just four:

      • Allen JG, 2016 raised the alarm about an additive, diacetyl, but failed to point out that, as one critic put it, "average diacetyl exposure from vaping is 750 times lower than from smoking".

      • Yu V, 2016 despite concluding that "e-cigarette vapor, both with and without nicotine, is cytotoxic to epithelial cell lines and is a DNA strand break-inducing agent", the study showed that cells exposed to the e-cigarette vapour medium were still alive after 8 weeks but all were dead in the tobacco smoke extract within 24 hours. This important comparison was buried in the paper, not mentioned in the abstract, and not included in the authors' publicity statements about the study.

      • Schweitzer KS, 2015 attempted to show that nicotine causes "dose-dependent loss of lung endothelial barrier function, which is associated with oxidative stress and brisk inflammation". But this study has been criticised for using nicotine exposures 500-50,000 times higher than nicotine concentrations in the blood of typical smokers or vapers: Cell studies on e-cigarettes: don’t waste your time reading (at least most of) them

      • Paley GL, 2016 concluded that e-cigarette battery fires and explosions were a "significant public health risk", based on six reported incidents. The authors asserted this without noting that in 2011 there were 90,000 smoking-material fires in the U.S. resulting in an estimated 540 civilian deaths, 1,640 civilian injuries and $621 million in direct property damage. To the extent vaping replaces smoking it will reduce this toll and result in a significant public health win.


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    1. On 2017 Jul 09, Jeffrey Ross-Ibarra commented:

      In our manuscript exploring the population genetics of local adaptation (Tiffin and Ross-Ibarra 2014) we included a discussion about the potential uses of reduced representation data (e.g. RAD-seq, GBS). To provide a sense of the probability of using reduced representation data to identify targets of selection, we included a figure showing the probability of having a SNP included in a region of the genome in which diversity had been severely reduced due to a recent selective sweep. Unfortunately this figure is not correct; an error in the code inadvertently used centimorgans as morgans, causing the recombination rate to be off by a factor of 100.

      To correct this we have generated a new figure (see http://rpubs.com/rossibarra/257207; raw code is available at https://gist.github.com/rossibarra/be44cc3b3796f45840d942ad11c01ba1) that corrects this error and presents a more realistic model. Our previous model assumed SNPs were distributed evenly across the genome and the presence of a single SNP near a sweep was sufficient for detection. Instead, here we explicitly model sequence “tags” coming from RAD-seq or GBS, and incorporate information about the variation in diversity expected among tags in neutral regions of the genome. The figure clearly shows that with dense marker coverage and strong selection, the probability of detecting reductions in diversity due to recent selective sweeps from new beneficial mutations can be relatively high. We emphasize, however, that the purpose of the figure is solely to develop an intuition of the likelihood of detecting a recent selective sweep. The many simplifying assumptions made in generating the figure (no recent demographic change, both sequence tags and recombination occur uniformly along the genome, selection is on a novel beneficial mutation with additive effect that has recently swept to fixation), as well as the specific mutation rates, sample size, sequence length, and recombination rates assumed will all affect the actual probability of a tag being included in a selective sweep. Moreover, this figure does not touch on many other relevant issue such as multiple testing, complex demography, background selection, or other modes of positive selection (e.g. from standing variation, balancing selection, or selection on polygenic traits).

      We have submitted a correction to the journal.

      We thank Eric Johnson for drawing our attention to the error, and Eric Johnson, Kathleen Lotterhos, and Graham Coop for kindly reviewing previous versions of the code and assumptions we have used in generating this new figure.


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    1. On 2014 Dec 03, Paolo Tieri commented:

      This article is one of the "Multi-omic Data Integration" Research Topic in Frontiers, which focuses on data integration approaches and methods of any type and extent, their application in understanding the pathogenesis of specific diseases or in identifying candidate biomarkers, in order to exploit the full benefit of multi-omic datasets and their intrinsic information content. For more information about multi-omic data integration check http://journal.frontiersin.org/ResearchTopic/2280


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    1. On 2015 Mar 17, Alan Taylor commented:

      This confirms work done to determine causes of OA in elderly patients. Aromatase deficiency is a key contributor to OA. Not only is it responsible for the final step in the synthesis of estrogen from androstendione but also converts testosterone to estrogen in males. The estrogen acts on two E receptors in female bone cells/ in males there is one androgen receptor and one estrogen receptor. These are a essential for bone health and maintenance. In the genome wide study under expression of CYP19 gene that codes for aromatase was evident in most cases. Severe OA in a male has been successfully treated for 15 years using a low dose of transdermal estrogen. This effect has been shown to be reversible It takes 6 to 8 weeks for the treatment to reverse the OA. Discontinuation causes OA to redevelop after 6-8 weeks. Recommencement again reverses the OA to give no symptoms whatsoever. Aromatase inhibitors will obviously prevent the two E receptors in the osteocytes from working. In males testosterone deficiency also will prevent the aromatase from catalysing the formation of estrogen.


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    1. On 2015 Apr 26, Geriatric Medicine Journal Club commented:

      This is a systematic review of non-pharmacologic interventions for orthostatic hypotension including exercise, FES, compression, physical countermaneuvers, head of bed up, water intake, and meal strategies. This article was critically appraised at the April 2015 Geriatric Medicine Journal Club (follow #GeriMedJC on Twitter). The full discussion can be found at: http://gerimedjc.blogspot.com/2015/04/april-2015-gerimedjc.html?spref=tw An interesting finding was that an acute bout of exercise may exacerbate orthostatic hypotension in short term. This review did not cover interventions like salt intake.


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    1. On 2015 Feb 09, David Keller commented:

      Dr. Lee,

      Your arguments against prescribing ezetimibe at this time are very persuasive, especially with regard to the cost of preventing cardiovascular events with this drug, even if the recent reports of such efficacy are eventually verified. This kind of perspective from a cardiovascular scientist is most beneficial to general internists like me.

      Your comments regarding rosiglitazone form a sort of inverse analogy to ezetimibe; if physicians who prescribed rosiglitazone are not to be condemned for "guessing wrong" in advance of the data proving that drug was harmful, then physicians who prescribed ezetimibe should not be congratulated for "guessing right" if this drug is proven to be beneficial. Good point.

      However, I chose never to prescribe rosiglitazone, even before its harmful outcomes were known. My decision was not due to luck or clairvoyance, but to the simple fact that rosiglitazone raises LDL cholesterol, and a very similar alternative drug (pioglitazone) exists which lowers LDL cholesterol instead. Knowing that every point of LDL increase in a diabetic is correlated with increased cardiovascular risk, I thought it would be folly to choose an agent which worsened LDL, even if it was only a surrogate marker.

      So, all of these examples get back to the question of the strength of LDL-lowering as a surrogate marker for reduction of cardiovascular events. The example of rosiglitazone versus pioglitazone seems to strengthen LDL as a valid surrogate marker for events. It appears that the new data for ezetimibe will also do so, if it confirms that this weak LDL-lowering drug also weakly improves cardiovascular event rates. Of course, ezetimibe still may not be worth its cost, as you point out, and that appears to be the bottom line, at least until ezetimibe is available as a cheap generic medication.


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    2. On 2015 Feb 03, Todd Lee commented:

      Dr. Keller,

      You do make a very interesting point about hindsight.

      It is a fact that billions of dollars have been spent in North America on a drug that, to date, does not have any high quality published evidence of efficacy in terms of clinical endpoints. This drug was thus used on the basis of theoretical arguments and a belief that lower LDL means lower events. The findings of IMPROVE-IT may suggest that some patients that have received this drug all of this time did derive benefit. However, based on the effect size in the trial and the patients enrolled, this may be the minority -- and at a considerable health care cost for each benefit.

      I'm really not sure what to infer about physicians who believed in the drug all this time. Are they to be commended for being correct?

      I'm not certain that money could not have been used for greater benefit with another intervention -- that is a question for health care economists; however, at $1,000,000 per event prevented (earlier post) it seems likely there may have been a more cost effective option.

      Let me contrast that with another example as I believe the case for ezetimibe and LDL is analogous to what people believed about hemoglobin A1c and the complications of diabetes. ROSIGLITAZONE was an extremely popular drug in 2006 -- to the tune of US prescriptions exceeding 2 billion dollars. This was because people inferred that lower A1c meant improved outcomes. Later, after the landmark paper showed that ROSIGLITAZONE might have been associated with increased cardiovascular risks, the sales plummeted to less than 15 million dollars in 2012. Thousands of lawsuits were settled and billion dollar fines were paid (for ROSIGLITAZONE and issues around other drugs) by the manufacturer. Furthermore, that drug was withdrawn from numerous European markets.

      I'm not sure what to infer about all of the physicians who believed in that drug. Are they all to be condemned? The answer is no. Physicians do the best they can for their patients within the limits of current medical knowledge. They had no a priori way of knowing that this intervention may actually harm patients more than help them.

      That said, it is not an accident that both agents were billion dollar winners for their prospective companies and that they were heavily marketed.

      Our group incidentally received a marketing pamphlet on ezetimibe in the mail today extolling the IMPROVE-IT trial. The jist of it: the lipid hypothesis is reaffirmed and ezetimibe has been proven effective in patients at risk of coronary artery disease. Does it matter that the paper hasn't been peer reviewed or put in the context of all of the negative papers before it? Not at all. That wouldn't be very good marketing.


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    3. On 2015 Jan 24, David Keller commented:

      Thank you, Dr. Lee, for that thorough, informative and excellent reply to my comment. For many years, I avoided prescribing ezetimibe (either alone or with a statin) due to the lack of data documenting improved outcomes. Prior to IMPROVE-IT, I would not have questioned the need for your study, and I would have been curious to learn why other clinicians were prescribing ezetimibe despite its interesting ability to improve lipids but not outcomes. Other non-statins which improve lipids - such as niacin, fibrates and bile acid sequestrants - had been able to demonstrate improved cardiovascular outcomes, at least in certain populations or under certain circumstances. The reports of improved outcomes from IMPROVE-IT seemed to reaffirm the importance of lowering LDL and to remove the major obstacle which had prevented me from adding ezetimibe when patients failed to achieve their LDL goal on a tolerable dose of statin. Based on the reservations you have expressed regarding IMPROVE-IT, I will hold back from prescribing it until the questions you raised are answered.

      For the sake of discussion, assume that cardiovascular outcome benefits of ezetimibe are eventually proved to your satisfaction. How, then, would that affect the utility of your investigation of why physicians were prescribing a drug which lacked outcome data, if their patients were thereby benefiting from lower event rates? These physicians may have prescribed ezetimibe based on their anecdotal experience with the drug, their knowledge of lipid physiology and pharmacology, or other factors, making them guilty of nothing more than being ahead of the randomized trial data, correctly predicting the outcome benefits of ezetimibe, and benefiting their patients with better outcomes sooner than more conservative physicians like me. Should we be trying to "correct" that kind of "mistake"?


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    4. On 2015 Jan 24, Todd Lee commented:

      As stated in our paper, we need the data from IMPROVE-IT to better inform us on the use of ezetimibe. However, rather than relying on a conference presentation and press releases we will also need to await the peer-reviewed and sponsor-independent analysis of the IMPROVE-IT trial to judge the quality of the results and evaluate their impact on general practice. Given interim analysis was performed (and the study was subsequently re-sized) any multiple comparisons performed will require expert statistical review.

      Furthermore, given no other positive studies exist, it may be prudent to perform an independent individual patient data analysis of all similar studies to better refine or confirm the estimate of effect prior to making any final conclusions from one trial.

      The net conclusion of this study, if the presented data is taken at face value, is a number needed to treat (NNT) of 50 over 7 years for the composite outcome. Overall mortality was not reduced. At generic Canadian prices it would cost approximately $58,765 to prevent 1 event over 7 years (Ontario formulary price as of January 2015). However, at US brand name prices of approximately $8.50 per day (Lexicomp 2015) the cost of preventing one composite outcome would be more than $1,000,000.

      It is also important to note that IMPROVE-IT was a secondary prevention study (acute event within 10 days) and not primary prevention. In primary prevention, the NNT is likely much higher and the corresponding costs per event prevented would increase proportionately and likely be substantial even at generic prices. In our cohort 6/17 (35%) were receiving ezetimibe for primary prevention.

      Whether the drug lowers event rates in the absence of a statin remains unproven and cannot be inferred from this study. Nonetheless, it will be interesting to see the effects on monotherapy uptake given the publicity around this study and also when IMPROVE-IT is ultimately published.

      The impact of this study on the uptake of other drugs approved on the basis of LDL as a surrogate marker is also not to be underestimated. The issue of treating to specific LDL targets is currently being debated amongst experts after recent changes to the guidelines. It would be somewhat naive to think that there isn't a substantial market pressure behind bringing back targets to be measured and obtained through additional medications.


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    5. On 2015 Jan 23, David Keller commented:

      Recent evidence of ezetimibe outcome benefits undermines the premise of this study

      The underlying premise of this study of ezetimibe prescribing patterns is that there is “a lack of evidence supporting its efficacy” in reducing adverse cardiovascular outcomes, despite its demonstrated efficacy in improving lipids and other surrogate endpoints (1).

      In the recently reported “IMPROVE-IT” study, patients taking ezetimibe plus simvastatin experienced significantly fewer major cardiovascular events (as measured by a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, rehospitalization for unstable angina or coronary revascularization occurring at least 30 days after randomization) than patients treated with simvastatin alone (2).

      Now that there is evidence that ezetimibe improves cardiovascular outcomes, the question of why clinicians prescribed it inappropriately in the past seems moot. Perhaps their clinical experiences using ezetimibe convinced them that evidence of beneficial outcomes would emerge over time. If ezetimibe was improving outcomes all along, then studies based on the premise that it should not have been used seem less relevant.

      References:

      1: McDonald EG, Saleh RR, Lee TC. Ezetimibe use remains common amongst medical inpatients. Am J Med. 2014 Oct 19. pii: S0002-9343(14)00917-6. doi: 10.1016/j.amjmed.2014.10.016. [Epub ahead of print] PubMed PMID: 25448168.

      2: Kohno T. Report of the American Heart Association (AHA) Scientific Sessions 2014, Chicago. Circ J. 2014 Dec 15. [Epub ahead of print] PubMed PMID: 25502168.


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    1. On 2017 May 21, Misha Koksharov commented:

      This paper provides interesting insights on the role of the 471–481 and 487–495 flexible regions in P. pyralis luciferase and on their utility in improving its thermostability.

      For those interested to investigate this topic further, I suggest to look also at the substitution D475P. As can be seen in the alignments below, this substitution occurs naturally in Luciola and in many other beetle luciferases:

      D476: http://forumbgz.ru/user/upload/file33577.gif

      D489: http://forumbgz.ru/user/upload/file33578.gif

      Moreover, in the available structures of L. cruciata luciferase the region 471–481 is not flexible - in contrast to P. pyralis enzyme - so I expect that this mutation should work (where the mutations D476P (Yu H, 2015) and D476N (Amini-Bayat Z, 2012) were inefficient). Interestingly, the successful substitution H489P also naturally occurs in many pH-insensitive luciferases (as shown in the alignments above).


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    1. On 2015 May 26, Paul Brookes commented:

      Portions of Figure 4 and Figure 5 from this paper appear more similar than would be expected by chance, when compared to portions of Figure 3 and Figure 8, from Zhao ZQ, 2012 Br J Pharmacol. 167, 1550-1562, PMID: 22823335

      Relevant information is available in the following two images... http://imgur.com/0DI1G78 http://imgur.com/u47Fdr8

      Usual disclaimers apply - i.e. go look for yourself at the originals and decide if they're similar, don't take my word for it, no implications about motives or underlying causes of this apparent similarity should be taken from this comment.

      That being said, the lead author has had two papers retracted for similar matters... http://retractionwatch.com/2015/05/26/heart-repair-study-retraction-marks-second-for-mercer-unviersity-researcher/


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    1. On 2016 Aug 24, Ben Goldacre commented:

      This trial has the wrong trial registry ID associated with it on PubMed: both in the XML on PubMed, and in the originating journal article. The ID given is NCT097115. We believe the correct ID, which we have found by hand searching, is NCT01857388.

      This comment is being posted as part of the OpenTrials.net project<sup>[1]</sup> , an open database threading together all publicly accessible documents and data on each trial, globally. In the course of creating the database, and matching documents and data sources about trials from different locations, we have identified various anomalies in datasets such as PubMed, and in published papers. Alongside documenting the prevalence of problems, we are also attempting to correct these errors and anomalies wherever possible, by feeding back to the originators. We have corrected this data in the OpenTrials.net database; we hope that this trial’s text and metadata can also be corrected at source, in PubMed and in the accompanying paper.

      Many thanks,

      Jessica Fleminger, Ben Goldacre*

      [1] Goldacre, B., Gray, J., 2016. OpenTrials: towards a collaborative open database of all available information on all clinical trials. Trials 17. doi:10.1186/s13063-016-1290-8 PMID: 27056367

      * Dr Ben Goldacre BA MA MSc MBBS MRCPsych<br> Senior Clinical Research Fellow<br> ben.goldacre@phc.ox.ac.uk<br> www.ebmDataLab.net<br> Centre for Evidence Based Medicine<br> Department of Primary Care Health Sciences<br> University of Oxford<br> Radcliffe Observatory Quarter<br> Woodstock Road<br> Oxford OX2 6GG


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    1. On 2015 Mar 05, Anders Prior commented:

      High effect sizes and immortal person-time

      In a paper published in Medicine, Wang et al. presented this cohort study of 47,225 stroke patients.<sup>1</sup> (Wang JY, 2014) They concluded that the 30-day mortality after stroke was significantly reduced if treatment with antipsychotic drugs was initiated before or after the stroke.

      The reported effect sizes were very large; the mortality rate in stroke patients decreased by 73% in those who received antipsychotic treatment before the stroke and by 87% in those who received antipsychotic treatment shortly after the stroke. Effects of this size are rarely seen in such studies.

      The study was based on a nested case-control design. Included cases were stroke patients who died within 30 days after having a stroke, while controls (matched on age, gender and stroke date) were stroke patients who survived at least 30 days after their stroke. The main exposure was antipsychotic drugs given at any time within 30 days after the stroke date. Multivariate logistic regression was used to calculate odds ratios of mortality.

      We are concerned that the results may be substantially biased because the definition of the antipsychotic user group conditions on the future; in order to receive the antipsychotic treatment and become a member of the antipsychotic user group, study participants need to survive until the drug is prescribed. In other words, study participants in the antipsychotic user group are ‘immortal’ until the day of treatment (immortal person-time).<sup>2</sup> The authors do not describe any analytical measures taken to counteract this conditioning. If they have not taken this into account, this would pose a very serious problem as also described numerous times in the epidemiological literature.<sup>3</sup> (Hanley JA, 2014) Immortal time bias will generate an illusion of treatment effectiveness and is frequently found in observational studies that compare with non-users.<sup>4</sup> (Suissa S, 2007)

      In general, suspicion for immortal time bias should be raised when exposure groups are assigned with no regard to exposure time in a longitudinal study. Furthermore, the reported effect sizes are surprisingly high, especially when considering the fragility of the population in question. This group consists of stroke patients with complications; they may suffer from e.g. post-stroke delirium and may need antipsychotic treatment. They would most likely have more adverse outcomes, not the opposite.<sup>5,6</sup> (Shi Q, 2012, Prior A, 2014)

      Dr. Anders Prior, MD

      Research Unit for General Practice and Section for General Medical Practice, Department of Public Health, Aarhus University, Denmark

      Dr. Thomas Munk Laursen, PhD

      National Centre for Register-based Research, Department of Economics and Business, Aarhus University, Denmark

      Prof. Mogens Vestergaard, PhD

      Research Unit for General Practice and Section for General Medical Practice, Department of Public Health, Aarhus University, Denmark

      References

      1 Wang JY, Wang CY, Tan CH, Chao TT, Huang YS, Lee CC. Effect of different antipsychotic drugs on short-term mortality in stroke patients. Medicine (Baltimore). 2014;93(25):e170.

      2 Rothman KJ, Greenland S, Lash TL. Modern Epidemiology. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2008.

      3 Hanley JA, Foster BJ. Avoiding blunders involving 'immortal time'. Int J Epidemiol. 2014;43(3):949-961.

      4 Suissa S. Immortal time bias in observational studies of drug effects. Pharmacoepidemiol Drug Saf. 2007;16(3):241-249.

      5 Shi Q, Presutti R, Selchen D, Saposnik G. Delirium in acute stroke: A systematic review and meta-analysis. Stroke. 2012;43(3):645-649.

      6 Prior A, Laursen TM, Larsen KK, et al. Post-stroke mortality, stroke severity, and preadmission antipsychotic medicine use--a population-based cohort study. PLoS One. 2014;9(1):e84103.


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    1. On 2015 Jan 12, Larry Parnell commented:

      This paper was my selection for Paper of the Week for 1-5 Dec 2014.

      This is highly important work and the conclusions drawn are valuable and applicable to many areas of genetic research into complex phenotypes. It is great to see scientists of this stature adding important insight into the role of GxEs, especially in terms of influence on gene expression.

      I don't feel that the relationship described in this paper for ADIPOQ is so meaningful as the variant described is not in high LD in most populations with the ADIPOQ variants that support known GxE interactions for cardiometabolic phenotypes. See http://www.biodatamining.org/content/7/1/21 Nonetheless, there is also in the BioData Mining article a list of GxEs described for UCP2, which does have evidence in this report above.


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    1. On 2016 Aug 23, Ben Goldacre commented:

      This trial has the wrong trial registry ID associated with it on PubMed: both in the XML on PubMed, and in the originating journal article. The ID given is NCT0093283. We believe the correct ID, which we have found by hand searching, is NCT00932893.

      This comment is being posted as part of the OpenTrials.net project<sup>[1]</sup> , an open database threading together all publicly accessible documents and data on each trial, globally. In the course of creating the database, and matching documents and data sources about trials from different locations, we have identified various anomalies in datasets such as PubMed, and in published papers. Alongside documenting the prevalence of problems, we are also attempting to correct these errors and anomalies wherever possible, by feeding back to the originators. We have corrected this data in the OpenTrials.net database; we hope that this trial’s text and metadata can also be corrected at source, in PubMed and in the accompanying paper.

      Many thanks,

      Jessica Fleminger, Ben Goldacre*

      [1] Goldacre, B., Gray, J., 2016. OpenTrials: towards a collaborative open database of all available information on all clinical trials. Trials 17. doi:10.1186/s13063-016-1290-8 PMID: 27056367

      * Dr Ben Goldacre BA MA MSc MBBS MRCPsych<br> Senior Clinical Research Fellow<br> ben.goldacre@phc.ox.ac.uk<br> www.ebmDataLab.net<br> Centre for Evidence Based Medicine<br> Department of Primary Care Health Sciences<br> University of Oxford<br> Radcliffe Observatory Quarter<br> Woodstock Road<br> Oxford OX2 6GG


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    1. On 2015 Jan 07, Mohammad Salman commented:

      I'm surprised by the findings of this paper since several authors have reported antiinflammatory effects of Thymoquinone and inhibition of COX-2 and PGE2 via Thymoquinone. See:

      1: Kundu JK, Liu L, Shin JW, Surh YJ. Thymoquinone inhibits phorbol ester-induced activation of NF-κB and expression of COX-2, and induces expression of cytoprotective enzymes in mouse skin in vivo. Biochem Biophys Res Commun. 2013 Sep 6;438(4):721-7. doi: 10.1016/j.bbrc.2013.07.110. Epub 2013 Aug 1. PubMed PMID: 23911786.

      2: Al Wafai RJ. Nigella sativa and thymoquinone suppress cyclooxygenase-2 and oxidative stress in pancreatic tissue of streptozotocin-induced diabetic rats. Pancreas. 2013 Jul;42(5):841-9. doi: 10.1097/MPA.0b013e318279ac1c. PubMed PMID: 23429494.

      3: El Mezayen R, El Gazzar M, Nicolls MR, Marecki JC, Dreskin SC, Nomiyama H. Effect of thymoquinone on cyclooxygenase expression and prostaglandin production in a mouse model of allergic airway inflammation. Immunol Lett. 2006 Jul 15;106(1):72-81. Epub 2006 May 22. PubMed PMID: 16762422.

      4: Marsik P, Kokoska L, Landa P, Nepovim A, Soudek P, Vanek T. In vitro inhibitory effects of thymol and quinones of Nigella sativa seeds on cyclooxygenase-1- and -2-catalyzed prostaglandin E2 biosyntheses. Planta Med. 2005 Aug;71(8):739-42. PubMed PMID: 16142638.


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    1. On 2015 Aug 17, Anders von Heijne commented:

      It is so interesting to compare the workings of our different healthcare systems. The type of order/referral for overread of outside radiological stuies described in this paper have been used in swedish radiology for at least as long as I have been in practice - ie at least for three decades. In addition to the obvious advantages described by the authors, the clinican that places the overread order can add relevant facts and queries in the new order. One easy way of documenting the outside report is to add it as a DICOM image to the study and save it in the PACS, rather than transfering it between different RIS.


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    1. On 2015 Oct 22, Horacio Rivera commented:

      A de novo inv dup(1) turns out to be a rea(1)dup q chromosome I remark that the de novo mosaic 1q32→qter duplication onto 1pter (concomitant with a normal clone) described by Levy et al. [2015] is not an inverted duplication because direct and inverted duplications are officially defined as “a gain of a chromosomal segment observed at the original chromosome location” [Shaffer et al., 2013], not to mention that the orientation of the extra segment was indeed a direct one. It is significant that in their discussion, Lévy et al. [2015] refer to three other similar chromosome-1 rearrangements entailing an 1q duplication (although none with interstitial telomeric repeats) and visualize them as “recombinants” from an hypothetical pericentric inversion. In this regard, a compilation of 104 recombinant-like chromosomes of de novo or sporadic occurrence [Rivera et al., 2013] lists 11 other comparable chromosome-1 composites entailing dup q/del p but without an interstitial telomere. To avoid a nonsensical “der vs rec” controversy, we have designated such rearranged chromosomes with the official term rea coupled with the lengthy description of the novel composite [Rivera et al., 2013]. In that paper, we pointed out that “this formula makes no causal assumptions, unambiguously describes the rearranged chromosome, allows for a meiotic or mitotic origin, and is consistent with the involvement of 1 or 2 homologs”. Moreover, the term rea had already been used for this purpose [Thomas et al., 2006] and properly describes a rearranged unbalanced chromosome mimicking a recombinant ensued from a pericentric inversion as it is epitomized by the rea(1)(qter→q32::pter→qter) here alluded to. It goes without saying that inv dup is also improperly used to designate mirror structures such as isodicentrics and neocentric isofragments [e.g., Warburton et al., 2000]. Although Lévy et al. [2015] recognized that “[T]he recurrent nature of all these similar recombinants, including our dup(1q), suggests an identical mechanism of formation”, they failed to identify it. According to D’Angelo et al. [2009], who analyzed in fine detail two dup q/del p and two other comparable chromosome-1 rearrangements, the DNA repair mechanism of non-homologous end joining (NHEJ) appears to be “the pathway in the formation of these de novo nonreciprocal translocations, because of the lack of evidence to support a homology-based recombination mechanism”. Yet, the location in unique, non-repetitive DNA sequences of all the breakpoints in the four chromosome-1 rearrangements above mentioned [D’Angelo et al., 2009] may call into question the NHEJ mechanism for rearranged chromosomes with an interstitial telomere alike to the exceptional rea(1) documented by Lévy et al. [2015]. Because Lévy et al. [2015] also omitted some relevant references on other rearrangements with interstitial telomeres, I reiterate here the academic and moral duty that authors, reviewers, editors, and readers have to improve the current citation practices [Rivera, 2014]. Finally, I stress that seven months ago a Letter to the Editor with these comments was judged unacceptable by the concerned journal because “the conclusions of Dr. Levy's paper are really not about terminology and nomenclature”. REFERENCES D’Angelo CS, Gajecka M, Kim CA, Gentles AJ, Glotzbach CD, Shaffer LG, Koiffmann CP. 2009. Further delineation of nonhomologous-based recombination and evidence for subtelomeric segmental duplications in 1p36 rearrangements. Hum Genet 125:551-563. Lévy J, Receveur A, Jedraszak G, Chantot-Bastaraud S, Renaldo F, Gondry J, Andrieux J, Copin H, Siffroi J-P, Portnoï M-F. 2015. Involvement of interstitial telomeric sequences in two new cases of mosaicism for autosomal structural rearrangements. Am J Med Genet Part A 167A:428-433. Rivera H. Commentary: peer review and incomplete reference lists. 2014. Account Res 21:138-141. Rivera H, Domínguez MG, Vásquez-Velásquez AI, Lurie IW. 2013. De novo dup p/del q or dup q/del p rearranged chromosomes: review of 104 cases of a distinct chromosomal mutation. Cytogenet Genome Res 141: 58-63. Shaffer LG, McGowan-Jordan J, Schmid M. 2013. ISCN 2013: an international system for human cytogenetic nomenclature (2013), Basel, S Karger. p. 69. Thomas NS, Durkie M, Van Zyl B, Sanford R, Potts G, Youings S, Dennis N, Jacobs P. 2006. Parental and chromosomal origin of unbalanced de novo structural chromosome abnormalities in man. Hum Genet 119: 444-450. Warburton PE, Dolled M, Mahmood R, Alonso A, Li S, Naritomi K, Tohma T, Nagai T, Hasegawa T, Ohashi H, Govaerts LC, Eussen BH, Van Hemel JO, Lozzio C, Schwartz S, Dowhanick-Morrissette JJ, Spinner NB, Rivera H, Crolla JA, Yu C, Warburton D. 2000. Molecular cytogenetic analysis of eight inversion duplications of human chromosome 13q that each contain a neocentromere. Am J Hum Genet 66:1794-1806.


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    1. On 2014 Nov 27, Jürgen Hänggi commented:

      Dear community

      this new study shows that a recently published "apparent" sex effect in the form of "increased interhemispheric connectivity in women and increased intrahemispheric connectivity in men" (see http://www.ncbi.nlm.nih.gov/pubmed/24297904) is driven by brain size and not by sex per se.


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    1. On 2015 Sep 03, Lydia Maniatis commented:

      It seems generally to be the case that when a darkish-looking surface grows in area, it appears to lighten. There is no doubt that this occurs, and also no doubt that the effect is subject to a large degree of variability between experiments and between individuals. Boyaci et al (2014) report, as their main finding, that the effect occurs in the context of "computer-rendered scenes" (their stimuli) as well as in the context of "real scenes" (referring to the rarefied laboratory set-up of Radonjic and Gilchrist (2014)).

      As a way of describing experimental conditions - whose results, moreover, were subjected to technical analyses to determine which datasets fit a linear model, a quadratic model, a one-phase model, a two-phase model, and used to form hypotheses about the neurophysiological underpinnings of performance and to judge conceptual models - the crude distinction between "computer-rendered" and "real" seems rather insufficient. Indeed, when it comes anything more specific than the general consistency with the "larger gets lighter" effect, all bets are off. Noting that their results were different from those of Radonjic and Gilchrist (2014), the authors speculate simply that: "The disagreement between our studies is likely to be because of differences between the stimuli." More specifically: "Whereas their stimuli (Radonji砦 Gilchrist, 2014) were real and as simple as possible, ours were computer generated and relatively more complex." Like the unqualifed "real" vs "computer-generated" distinction, the "simple vs complex" distinction is too vague for the purpose. Very subtle and neurophysically complex perceptual operations can be triggered by geometrically simple stimuli. Surely, mathematical modelling and theoretical/neurophysiological extrapolations should follow, not precede, qualitative understanding of a phenomenon and the effects of conditions. Otherwise, such speculation is strictly ad hoc.

      The "area rule" as originally proposed said more than that the darker of two areas will lighten with area. It said that this lightening of the darker area will "anchor" cause the appearance of the lighter area such that it brightens and eventually becomes luminous. The proposal was made in order to rationalize the luminosity observed in the disc in classic disc/annulus experiments, without having to ascribe a role to figure-ground organization. The predicted changes in the lightness of the lighter area qua area apparently haven't been corroborated and are no longer referred to or tested for. As an isolated phenomenon not affecting surrounding surfaces, it's hard to see the theoretical importance of a highly-variable and condition-sensitive tendency toward lightening of relatively darker surface with increases in area, or the value of making fussy models of this tendency, tailored to particular stimuli.

      I would also like to take issue with the choice of references the authors chose to support their opening assertion that "The lightness of a surface depends not only on its luminance but also on its geometry and the context within which it is viewed (Boyaci, Doerschner, Snyder, & Maloney, 2006; Gilchrist, 2006; Kingdom, 2011; Maloney, Boyaci, & Doerschner, 2005; Maloney, Gerhard, Boyaci, & Doerschner, 2010)." The case for this was made in classic literature and experiments well before 2006. The assertion is so fundamental and uncontroversial that references are not even necessary.


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    1. On 2015 Nov 04, Lydia Maniatis commented:

      Continuation of "area rule" story: Avoiding acknowledging the role of figure-ground in contrast effects also allowed advocates of "anchoring theory" to claim that "the debate seems to revolve around layer models and framework models" (Gilchrist, 2015), frameworks being adjacent "like countries on a map." Figure-ground structure means layers, and so would complicate this presentation.


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    2. On 2015 Sep 20, Lydia Maniatis commented:

      In line with the earlier point about avoiding figure/ground issues, the "multi-sector" stimuli used here are of the sort used by Gestalt psychologists to demonstrate and study figure-ground effects (e.g. the role of sector color, size, orientation; bistability). But such effects and their potential lightness consequences are not acknowledged.


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    3. On 2015 Sep 17, Lydia Maniatis commented:

      "Simple" vs "complex" stimulus is not a meaningful distinction, because there is no objective criterion for making it. Geometric simplicity may or may not produce complexity in the percept, of different kinds.

      Which is more simple: a. the three pacmen of a Kanizsa triangle, that produce subjective contours/ contrast/amodal completion; b. the simultaneous contrast effect that produces contrast and amodal completion? c. the de Valois checkerboard that produces assimilation; d. a random array of variously shaped, overlapping white, grey, black shapes? e. the checkerboard used here, which produces transparency/inhomogenous illumination effects; f.a black shape that produces the impression of two overlapping black shapes; g. etc.

      The authors offer their own “clear distinction” of simple vs complex. Not only is this proposed distinction unclear, it lacks theoretical content. The authors subsequently seem to ignore it, and use the terms in a loose and undefined way. The proposed distinction, attributed to “anchoring theory” is: “A simple image is one in which all the surfaces lie within a single illumination level (a single framework) whereas complex images contain multiple adjacent fields of illumination (multiple frameworks).” This distinction is theoretically hollow, because it references actual (actual level of illumination) and not perceived (perceived illumination) image features. By this definition, a photograph of sunlight and shadow should count as a single framework, provided it is being viewed under a homogeneous illumination. Even if we take the authors' distinction to refer to perceived illumination (which begs the question the “frameworks” argument is supposed to answer, i.e. how do we parse the scene into separate illumination “frameworks”), they don't stick to it. A little later, for example, we are told that the stimuli of Boyaci et al (2014) “are still fairly simple, [but] qualify [] as complex as they consist of more than one framework” (the distinction is invoked to explain discrepancies between those authors findings and the findings of R and G (2014). But Boyaci et al's stimuli are neither under inhomogeneous illumination nor are they designed to create such an impression. So the definition of “framework,” which wasn't explanatory to begin with, has shifted in the space of a few paragraphs, from “framework of illumination” to something else (what?). We are similarly told that “a dozen previous experiments...used images that qualify as complex images;” but many (perhaps all) of these studies did not involve inhomogeneous illumination, real or perceived.


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    4. On 2015 Sep 17, Lydia Maniatis commented:

      A short, instructive history of the “area rule”

      The “area rule” was born in an attempt to deny the role of figure-ground structure in lightness. This is its original sin, and has led to interesting distortions in theory and practice.

      Classic disc-annulus experiments, which demonstrated the dependence of lightness on luminance ratios, also showed an asymmetrical influence of disc and annulus. The annulus would always look white, and push a lighter disc towards luminosity. In other words, raising the luminance of the annulus would lighten the disc, but not vice versa. The disc appeared to lie on top of an amodally-completed larger disc, so an easy provisional conclusion would be to assign different influences to figure and ground in mediating lightness perception of a surface (the same asymmetry applies to figure-ground contrast in general).

      Gilchrist et al (1999) did not like this solution because it interfered with their preferred theoretical assumption that the highest luminance in a (vaguely-defined) “framework” would be white. Clearly, in the very simple, disc-annulus situation, the highest luminance was not necessarily white. Instead of acknowledging a role for figure-ground, Gilchrist et al (1999) created a new rule, stating that if the darker area was more than 50% larger than the smaller, then it would lighten, and progressively push the smaller, lighter area toward luminosity. They presented a speculative function, reprinted in Gilchrist and Radonjic (2009), that has never been corroborated, despite a number of attempts.

      The Gilchrist group's own results constantly cried out for a figure-ground explanation. Tellingly, they were forced to modify their area claim to include “amodally-completed” area – thus in effect making the area rule indistinguishable from a figure-ground claim. Later, Economou et al (2007) acknowledged a similar, figure-ground-related asymmetry in the simultaneous contrast display. The team acknowledged the asymmetry but did not explore it further.

      Preserving the highest-luminance-white rule was not the only or even most important incentive for rejecting a possible figure-ground role. Another fundamental claim of Gilchrist et al (1999) was that the classic simultaneous contrast demonstration is due to a process which, at a certain stage, treats each square and its interior as a separate “framework” and evaluates its contents based on the ratio principle and highest-luminance rule. The idea that the lightness of the targets is actually mediated by local luminance contrast between the apparent figure and its background was not compatible with this assumption. However, it is easy to show (Maniatis, 2015), by adding surfaces within each putative “framework” that border contrast between figure and ground, not the ratios with all surfaces contained in the background square, mediates this effect.

      The commitment to avoiding acknowledging a role for figure-ground explains, I believe, the preference manifested by investigators with these theoretical commitments for stimuli which either did not produce figure-ground effects, or in which the contrast effects would average out. Specifically, they adopted the use of checkerboards or Mondrians, and random or semi-random selection of luminances. Such stimuli and choices muddy rather than clarify the role of structure in lightness. Thus, proponents of a “Gestalt” theory, were, paradoxically forced by their commitments to prefer stimuli in which image structuring could be ignored.

      There was a second reason that this “Gestalt” theory needed to avoid confronting the role of structure in lightness, and this was that it did not/could not address the fact that we sometimes perceive surfaces as lying beneath transparent layers with their own lightness. As in the case of figure-ground/amodal completion effects, such layers arise when contours showing good continuation intersect, with the added proviso that the luminance structure is compatible with such a solution. Checkerboards, lacking such cues, avoid such effects.

      Well, actually, they don't. They often produce multiple such effects, as well as luminosity. This latter result arose in Radonjic et al (2011). It was awkward and they tried to explain it away by selectively attributing inconvenient results to presentation on an “emissive” screen. Allred et al (2012) tentatively acknowledged, after much highly technical wrestling with very low-resolution data, the self-evident yet apparently unplanned-for fact that checkerboards do produce differential lightness impressions. So restricting the class of allowable stimuli (rationalized on the basis that they were “simple” and that results would carry over to more “complex” situations – a view codified in the oft-repeated “applicability assumption”) in order to avoid confronting figure-ground and transparency effects has nevertheless led researchers back to these same, unavoidable issues.

      It is interesting that the checks on a checkerboard can coalesce into transparent overlays/underlying surfaces despite the absence of apparent overlap. It is surely not unrelated to the fact that checkerboards produce assimilation rather than contrast when we replace a black or white check with a grey one (the de Valois and de Valois checkerboard contrast demonstration). It would be worth analyzing.


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    5. On 2015 Aug 12, Lydia Maniatis commented:

      This article is a bit misleading. The authors seem to be claiming to have corroborated the area rule, at least for the case where the darker area fills more than half the visual field.

      As defined and illustrated by Gilchrist et al (1999) and Gilchrist and Radonjic (2009), the area rule predicts the onset of luminosity when the darker area exceeds half the display. But this prediction has never been corroborated, even for far, far larger darker area coverage, nor has the description of the rule changed. In addition, lightening of the darker are has never been shown to start until the latter covers far more than 50% of total area. So the claim that this study has corroborated the "area rule" needs to be qualified by the introduction of a new description of the area rule.


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    1. On 2013 Oct 25, DAVID SANDERS commented:

      From the abstract of Ueda T, 1989

      "Two proteins stimulating the GTPase activity of the smg-21 GTP-binding protein (smg p21) having the same effector domain as the ras proteins (ras p21s) are partially purified from the cytosol fraction of human platelets. These proteins, designated as smg p21 GTPase activating protein (GAP) 1 and 2, do not stimulate the GTPase activity of c-Ha-ras p21. smg p21 GAP1 and 2 are separated from c-Ha-ras p21 GAP by column chromatographies. The activity of smg p21 GAP1 and 2 is killed by tryptic digestion or heat boiling. The Mr values of smg p21 GAP1 and 2 are similar and are estimated to be 2.5-3.5 x 10(5) by gel filtration analysis. These results indicate that there are two GAPs for smg p21 in addition to a GAP for c-Ha-ras p21 in human platelets."


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    1. On 2014 Dec 10, Alberto Zambrano commented:

      Dear Ilya, The Ab used was initially described by Dr. Sonenberg (Mol Cell Biol. 1998 Jan;18(1):334-42, A novel functional human eukaryotic translation initiation factor 4G.) and was kindly donated by Dr. Cesar de Haro (CBM, Madrid, Spain) There you can see that the size of the recombinant form of EIF4G2 (His-tagged) (Figure 3) recognized by the Ab is a little bit lower than 206 KDa. You can also see another prominent band higher than 117KDa, recognized by the Ab. In a another article from the same author (J Neurosci. 2012 Apr 18;32(16):5620-30. doi: 10.1523/JNEUROSCI.0030-12.2012. Regulation of neuronal mRNA translation by CaM-kinase I phosphorylation of eIF4GII) the same Ab was also used but, unfortunately the protein markers were not indicated. In our blots, the Ab reactivity shows either a prominent, discrete band or a doublet at size indicated. We don't observe any other significant reactivity in the full blots. In addition, those bands were sensitive to specific specific siRNA downregulation (figure 5). We don't have a clue about the origin of such differential electroforetic mobility differencies, described in the original paper or in ours (in MEFs, with respect to the predicted size but with the evidences we had, we assumed that protein identity.


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    1. On 2014 Dec 03, Rafael Najmanovich commented:

      We predicted back in 2012 (Chartier M, 2012) as part of a large scale analysis of rare codon cluster that such clusters may play a role in the molecular recognition of the nascent protein for intracellular targeting and membrane insertion. It is unfortunate that the authors were not aware of our publication.


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    1. On 2015 Jan 03, William Grant commented:

      Here are some papers not included in this review showing benefits of vitamin D testing. Peiris AN, Bailey BA, Grant WB, Mascitelli L. Vitamin D testing. Lancet 2012 May 5;379:1699-1701.

      Der T, Bailey BA, Youssef D, Manning T, Grant WB, Peiris AN.,Vitamin D and prostate cancer survival in veterans. Military Med. 2014;179 (1) :81–84.

      Peiris AN, Bailey BA, Manning T. Relationship of vitamin D monitoring and status to bladder cancer survival in veterans. South Med J. 2013 Feb;106(2):126-30.

      Bailey BA, Manning T, Peiris AN. Vitamin D testing patterns among six Veterans Medical Centers in the Southeastern United States: links with medical costs. Mil Med. 2012 Jan;177(1):70-6.

      Of course some may have been published after your literature search was completed. However, they do support the benefits of vitamin D testing among hospital patients.

      Also, this paper is supportive in that it found that patients in the ICU with very low 25OHD concentrations benefited from vitamin D supplementation. Amrein K, Schnedl C, Holl A, Riedl R, Christopher KB, Pachler C, Urbanic Purkart T, Waltensdorfer A, Münch A, Warnkross H, Stojakovic T, Bisping E, Toller W, Smolle KH, Berghold A, Pieber TR, Dobnig H. Effect of High-Dose Vitamin D3 on Hospital Length of Stay in Critically Ill Patients With Vitamin D Deficiency: The VITdAL-ICU Randomized Clinical Trial. JAMA. 2014 Oct 15;312(15):1520-30.

      One of the impediments to acceptance of vitamin D seems to be the lack of supportive trials. The trials have not supported the ecological and observational studies largely because the trials have not been properly designed. Too often, people with normal to high 25OHD concentrations are enrolled and given a small amount of vitamin D. The proper way to conduct such trials was outlined recently in this paper: Heaney RP. Guidelines for optimizing design and analysis of clinical studies of nutrient effects. Nutr Rev. 2014 Jan;72(1):48-54.

      Disclosure I receive funding from Bio-Tech Pharmacal (Fayetteville, AR) and Medi-Sun Engineering, LLC (Highland Park, IL).


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    1. On 2014 Nov 28, Paolo Tieri commented:

      This article is one of the "Multi-omic Data Integration" Research Topic in Frontiers, which focuses on data integration approaches and methods of any type and extent, their application in understanding the pathogenesis of specific diseases or in identifying candidate biomarkers, in order to exploit the full benefit of multi-omic datasets and their intrinsic information content. For more information about multi-omic data integration check http://journal.frontiersin.org/ResearchTopic/2280


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    1. On 2016 Aug 23, Ben Goldacre commented:

      This trial has the wrong trial registry ID associated with it on PubMed: both in the XML on PubMed, and in the originating journal article. The ID given is NCT0160325. We believe the correct ID, which we have found by hand searching, is NCT01603251.

      This comment is being posted as part of the OpenTrials.net project<sup>[1]</sup> , an open database threading together all publicly accessible documents and data on each trial, globally. In the course of creating the database, and matching documents and data sources about trials from different locations, we have identified various anomalies in datasets such as PubMed, and in published papers. Alongside documenting the prevalence of problems, we are also attempting to correct these errors and anomalies wherever possible, by feeding back to the originators. We have corrected this data in the OpenTrials.net database; we hope that this trial’s text and metadata can also be corrected at source, in PubMed and in the accompanying paper.

      Many thanks,

      Jessica Fleminger, Ben Goldacre*

      [1] Goldacre, B., Gray, J., 2016. OpenTrials: towards a collaborative open database of all available information on all clinical trials. Trials 17. doi:10.1186/s13063-016-1290-8 PMID: 27056367

      * Dr Ben Goldacre BA MA MSc MBBS MRCPsych<br> Senior Clinical Research Fellow<br> ben.goldacre@phc.ox.ac.uk<br> www.ebmDataLab.net<br> Centre for Evidence Based Medicine<br> Department of Primary Care Health Sciences<br> University of Oxford<br> Radcliffe Observatory Quarter<br> Woodstock Road<br> Oxford OX2 6GG


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    1. On 2015 Apr 06, Jeffrey Ross-Ibarra commented:

      Muñoz-Fuentes et al. offer an interesting look at the relationship between domestication and recombination rate in animals. A quick correction worth mentioning: while they cite my 2004 paper on recombination and domestication in plants (PMID: 14767840) several times, it's done somewhat out of context. They quote me as saying

      '"recombination rate is likely of little importance" in relation to plant domestication (Ross-Ibarra 2004)'

      whereas the actual quote from my paper clearly referred specifically to preadaptation:

      "Other hypothesized genetic preadaptations, such as polyploidy (Hilu 1993), have been shown to be unimportant in determining the successful domestication of plant species, and the present analysis suggests that recombination rate is likewise of little importance."

      and the abstract is fairly unambiguous:

      "The results support the hypothesis that domestication selects for an increase in recombination..."


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    1. On 2014 Nov 30, Hilda Bastian commented:

      Thanks for the helpful and informative reply, Tetyana.

      While modeling can take account of some known variables, it can't overcome the limitations of measures based on these traditional theories. Other mechanisms that could explain the results remain. There are assumptions used to explain the results of these data simulations (such as that hiring and firing exposes people to conflict and hostility, but pay decisions do not) that remain open to question.

      The results do not exclude the possibility that the women did not have enough authority in comparison with the men with whom they were compared, or other associated (in)tangible benefits that the men could take for granted with the "hire/fire/influence pay" status. Having equal status may indeed have brought similar benefits. Adequate markers for a particular status attainment for the original in-group from whom the measures were derived, may lack the power to discriminate unequal status for others. If so, then like is not necessarily being compared with like. It wasn't possible to "take all other job characteristics into account," because they weren't measured.

      Using unreported modifications of measurement tools for the key outcome makes it difficult for others to be able to assess the validity of the data and its interpretation. It would be helpful if that were done within the larger project, and linked here. Depression implies an adverse mental health condition (both in the community and clinically), and the study's conclusions refer to health benefits, not happiness. The CESD has cut-offs for symptomatology that has no clinical relevance.

      While there's no doubt that workplace circumstances for women and other traditional "out groups" must change, I don't believe on the basis of this data that people should believe that workplace authority over others per se makes women depressed. But the data are enormously valuable, and this work is indeed an important contribution to addressing an important social issue. Thank you for that, as well as the additional information in your reply.


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    2. On 2014 Nov 30, Tetyana Pudrovska commented:

      Dear Hilda, thank you for your thoughtful and insightful comments and for engaging in this dialogue. It was a pleasure to ponder over the points you made and to consider our methodology, data, and findings from another perspective. Below are some of my thoughts.

      1. The measure of depression does not have a clear clinical relevance. Different terms are used interchangeably. Each item is coded 0 or 1.

      The most widely used term for the CES-D scale is depressive symptoms. We also use depression because it is a very general term that doesn’t refer to a clinical diagnosis. Depression is not a disease in the DSM, “major depressive disorder” is.

      The CES-D items (like almost all other measures of self-reported physical and mental health) are highly skewed because most people report no depressive symptoms. Hence, the dichotomization of each item. We conducted a variety of sensitivity analyses using different coding approaches for the outcome, such as averaging all items and taking a natural log to reduce the positive skew, and the findings were remarkably similar.

      The issue of using continuous scales vs binary diagnoses has received a lot of attention in sociology of mental health. Both approaches have strengths and weaknesses. Our findings hold in a variety of alternative models when we use a binary measure with a cutoff at the 75th percentile or at 10+ symptoms.

      Sociologists typically prefer continuous scales because they are better for capturing the stressful consequences of social inequality. Unlike clinicians, sociologists are interested in the full spectrum of mental health, not only its negative extremes. To uncover the effects of social structures and social relationships on individual mental health, we need a continuum from mild to very severe that enables us to compare social groups on this scale. Binary diagnoses can obscure important differences because people who have, for example, 5 symptoms are in the same category as people who have no symptoms.

      Because the effects documented in our study are large in magnitude and statistically significant after adjustment for many factors that are traditionally used to explain women’s higher depression, our findings provide important insights into the psychological consequences of social arrangements.

      Ultimately, clinical relevance is not consistent with the brunt of our argument. One of the major implications of our study is that a higher level of depression among women in authority positions is not a clinical issue that can be addressed by diagnosing and treating specific individuals. It’s a social issue that should be addressed at the macro-level of society and the meso-level of organizations.

      2. The observed differences in depression may reflect not the effect of job authority itself but the effects of many other job characteristics that differ between men and women with job authority.

      The workplace situation is certainly not equal between men and women in authority positions. It is well-documented that in the same occupations and at the same levels of human capital characteristics, women have lower earnings, lower autonomy, and lower levels of many other desirable workplace characteristics than men.

      Yet, the gender difference in depression documented in our study is not due to the differences in other job characteristics between men and women. Our models control for all these variables, and the effects of job authority are observed after we take all other job characteristics into account.

      In addition to multiple regression, we use counterfactual approach to improve causal inference. It’s also called a “quasi-experimental” design because it simulates random assignment in an experiment. Our approach matches people with job authority (the “treatment” group) and people without job authority (the “control” group) in 1993 on many characteristics, including baseline depression, education, occupation, earnings, weekly hours, job characteristics and job satisfaction, marriage, parenthood, and early-life characteristics, especially parents’ socioeconomic resources. By matching people, we make the two groups as similar as possible with the exception of job authority and then see how depression changes over time based on people’s authority status in 1993.

      It is also important that we conduct not only between-gender comparisons but also within-gender comparisons. Women with job authority have more depressive symptoms compared to women without job authority. In contrast, men with job authority have lower depression than men without job authority. What’s striking is that women with job authority in our study are socially advantaged in terms of most socioeconomic characteristics that are strong predictors of positive mental health. These women have more education, higher income, more prestigious occupations, and higher levels of job satisfaction and job autonomy than women without job authority. By all traditional models of socioeconomic status and health women with job authority should fare better than lower-status women. Yet we find the opposite.

      3. Absence of direct measures of interpersonal stress, harassment, and prejudice.

      Ideally we’d certainly like to have all possible measures of interpersonal stress and discrimination. But such a data set simply does not exist. The Wisconsin Longitudinal Study (WLS) that we use is currently among the best for our purposes. We are doing more work with other data sets, including the National Longitudinal Surveys, but all data have their advantages and limitations. So we are launching our own data collection. The current study, by documenting these patterns and providing a theoretically and empirically grounded interpretation, makes an important contribution and one of the first steps to address an important social issue.

      The WLS has very rich array of measures of job characteristics. We include all variables that are considered main stressors in traditional theories of work stress. Yet, the effect of job authority persists net of these traditional explanations, which bolsters the indirect evidence for the mechanisms we propose.

      The WLS started in 1957 and is still ongoing. We have information about our participants’ employment histories for the last 55 years. Job authority (but not depression) was measured for the first time in 1975 when our participants were 36 years old. We used this earlier measure of job authority in related articles that are all components of a larger project.


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    3. On 2014 Nov 29, Hilda Bastian commented:

      This paper uses the terms "depressive symptoms" and "depression" interchangeably. However, the relationship between the screening questions asked and the "clinical" condition of depression is unclear. A modified form of an unspecified version of the CESD screening tool was used. It included an unspecified 10 of the 16 CESD questions, applied only for the last week. In a further variation to the CESD, answers were scored with only a dichotomous outcome.

      The cut-off for determining "depression" was also not explained and the "clinical" relevance of the measure (and associated increase) is unclear. If there has been a validation of an association between the scores used here and depression, it was not referred to in the paper. More details on this would be helpful to people interested in interpreting the results of this study.

      The workplace situation was not equal between the men and women bracketed in the same job authority categories in this sample. The women worked fewer hours per week, earned less than the men of the same age, and were supervised more often. It's women's job authority with less pay and less freedom than men's job authority that is being compared. That would also be a function of the gender inequality the authors identify as a clear problem here. But it raises a question about the level of emphasis given to the psychological impact of having supervisory authority, and, therefore, to know what to do about it.

      The range of workplace factors addressed by this study include the traditional ones related to autonomy. Those questions don't address the kinds of gender-related issues the authors point to in the literature as constituting psychological workplace adversity for women in management: such as endemic social exclusion by peers and supervisors, frequent slights from all directions, being judged more frequently as socially disruptive, unequal opportunity and status attainment, and harassment. More sensitive tools (and relevant data from before the age of 54) would have been needed to unpack what made that generation of women unhappier than the men. The underlying point these authors show, though - that psychological aspects of the workplace experience have serious bearing on women's happiness - is a critical one.

      The full text of this article is available here.


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    1. On 2015 May 31, Shin Lin commented:

      This response discusses the manuscript submitted by Gilad and Mizrahi-Man at F1000Reseach, as well as our two responses at that journal. For details, we encourage interested individuals to read those various pieces.

      The batch effect that Gilad and Mizrahi-Man present as confounders of our findings are not the result of experimental protocols. Our sequencing libraries were largely prepared in one sitting by the same person, and we used matched primer indices/barcodes to minimize variation as observed in 't Hoen PA, 2013. The potential batch effect to which Gilad and Mizrahi-Man are referring is from sequencing on different lanes/flow cells/sequencing machines. In our experience, these effects are small (also found in 't Hoen PA, 2013), and we did not observe any such effects in the original published data. However, to further settle the issue, we reconstructed the sequencing libraries under a different multiplexing scheme to address their concerns, and we found the same clustering pattern as originally presented by Lin et al. Thus, we emphatically disagree with the conclusion from Gilad and Mizrahi-Man that our conclusions are “not warranted,” but rather, we argue that objective normalization procedures allow the discovery of the clustering of transcriptomes by species.

      Gilad and Mizrahi-Man found clustering by tissue after normalization, because in their attempt to account for lane/flow cell/sequencing machine effect, they normalized away the species effect. In that set of experiments, tissues of the same species were multiplexed on the same sequencing lane; accounting for primer indices would not have been possible otherwise. That normalization of the data by each species separately causes clustering by tissue was known to authors of Lin S, 2014, as this observation was presented in the Mouse ENCODE main paper Yue F, 2014.

      Gilad and Mizrahi-Man's work focused on one particular dataset in Lin S, 2014. However, that paper contains a principal component analysis (PCA) on data from multiple sources: Stanford (human, mouse), Salk (human), HBM (human), LICR (mouse), and CSHL (mouse). There are undoubtedly many technical differences between the various sources. Yet, the clustering by species was seen in higher order principal components (PCs) (see Figure 1A Lin S, 2014); clustering by tissues, in lower components (Figure 1B in Lin S, 2014) or by normalizing species separately (Extended Data Fig. 1C of Yue F, 2014). The same behavior is seen in the Stanford-only data—both in Lin S, 2014, which minimizes primer index effect (Figure 1C & 1D) and now the newly generated results that account for lane effect. The latter are consistent with our earlier observation that experimental batch did not drive the species-specific clustering.

      As for the latest criticisms concerning sample collection, these are issues outside the scope of the manuscript by Gilad and Mizrahi-Man. We state that our procurement practices are consistent with what other investigators have done and continue to do. When we limit our analyses to the small number of tissues examined by recent studies showing tissue specific-clustering (i.e. those with a large number of tissue-specific genes), we also find tissue specific clustering (see Figure 1F in Lin S, 2014). Thus, there are no inherent biases in our data which account for species-specific clustering. Rather, it is our complete dataset with many additional tissue types which results in the different clustering pattern. This evaluation of a broad tissue set is the critical difference which led to our finding of species-specific clustering. Indeed, when we examine the broad dataset of mouse and human CAGE expression data from the Riken Fantom 5 project (FANTOM Consortium and the RIKEN PMI and CLST (DGT)., 2014), we confirm species-specific clustering.

      Finally, as stated in the F1000 comment, we reiterate our enthusiasm of the mouse as a vital model system for experimental research, because of its many similarities to humans, which we show in our PNAS paper. However, an appreciation of the differences which exist between human and mouse will allow investigators to better interpret the disparities which are encountered when applying findings in the mouse model to humans.

      ***New data mentioned herein is available for download at the Mouse ENCODE website.

      Shin Lin<sup>1,2</sup> , Yiing Lin<sup>3</sup> , Michael A. Beer<sup>4</sup> , Thomas R. Gingeras<sup>5</sup> , Joseph R. Ecker<sup>6,7</sup> , Michael Snyder<sup>1</sup>

      <sup>1</sup> Department of Genetics, Stanford University, 300 Pasteur Drive, M-344 Stanford, California 94305; <sup>2</sup> Division of Cardiovascular Medicine, Stanford University, Falk Building, 870 Quarry Road Stanford, California 94304; <sup>3</sup> Department of Surgery, Washington University School of Medicine, 660 S. Euclid Ave., Campus Box 8109, St. Louis, Missouri 63110; <sup>4</sup> McKusick-Nathans Institute of Genetic Medicine and the Department of Biomedical Engineering, Johns Hopkins University, 733 N. Broadway, BRB 573 Baltimore, Maryland 21205; <sup>5</sup> Cold Spring Harbor Laboratory, Functional Genomics, 1 Bungtown Road, Cold Spring Harbor, New York 11742;<sup>6</sup> Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037; and <sup>7</sup> Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, CA 92037.

      Acknowledgement: We thank the other members of the Mouse ENCODE consortium in formulating this response.


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    2. On 2015 May 26, Steven Salzberg commented:

      Serious technical questions have been raised about the main conclusion of this paper. Specifically, Yoav Gilad and Orna Mizrahi-Man described how the human and mouse samples were processed separately in several ways, any of which could lead to a significant "batch effect." They published some of their findings in F1000 Research, at http://f1000research.com/articles/4-121/v1. They showed that after removing the batch effects, the finding that human and mouse genes cluster separately completely disappeared. In the discussion of that paper on the F1000 site, further sources of batch effects were identified. Thus it appears that the main finding of this paper cannot be supported by the data, because the samples from human and mouse were handled and processed in distinct ways, confounding the batch effect and any possible biological effect.


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    1. On 2015 Jan 24, Wichor Bramer commented:

      I think this article is a rathor open door article, in that its conclusions can be drawn beforehand, wihout executing the experiments. If you consider PICOS as PICO + S, surely then of course PICO will retrieve more relevant articles and PICOS sarches will be more specific. The searches used for testing PICOS were the exact searches for PICO, with an added element of S, which in this case was very basic (two or three tersm), compared to the exhaustive translation of the other elements (more than 10 terms). PICO, PICOS and SPIDER should not be used in the creation of search strategies. Not every element in those methods is necessary in a search query. Including specific outcomes and controls can introduce bias in the search results. For a good thorough systematic review, only P and I are used, and when necessary combined with a sensitive filter on study design, that consists of more than three terms and is verified (when possible). PICO, PICOS ad SPIDER can be useful in the process of evaluating the retrieved full text references for inclusion, but should not direct the search strategy.


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    1. On 2016 Aug 23, Ben Goldacre commented:

      This trial has the wrong trial registry ID associated with it on PubMed: both in the XML on PubMed, and in the originating journal article. The ID given is NCT00696414. We believe the correct ID, which we have found by hand searching, is NCT00696514.

      This comment is being posted as part of the OpenTrials.net project<sup>[1]</sup> , an open database threading together all publicly accessible documents and data on each trial, globally. In the course of creating the database, and matching documents and data sources about trials from different locations, we have identified various anomalies in datasets such as PubMed, and in published papers. Alongside documenting the prevalence of problems, we are also attempting to correct these errors and anomalies wherever possible, by feeding back to the originators. We have corrected this data in the OpenTrials.net database; we hope that this trial’s text and metadata can also be corrected at source, in PubMed and in the accompanying paper.

      Many thanks,

      Jessica Fleminger, Ben Goldacre*

      [1] Goldacre, B., Gray, J., 2016. OpenTrials: towards a collaborative open database of all available information on all clinical trials. Trials 17. doi:10.1186/s13063-016-1290-8 PMID: 27056367

      * Dr Ben Goldacre BA MA MSc MBBS MRCPsych<br> Senior Clinical Research Fellow<br> ben.goldacre@phc.ox.ac.uk<br> www.ebmDataLab.net<br> Centre for Evidence Based Medicine<br> Department of Primary Care Health Sciences<br> University of Oxford<br> Radcliffe Observatory Quarter<br> Woodstock Road<br> Oxford OX2 6GG


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    1. On 2016 Sep 14, Peter Hajek commented:

      There exists a simple test of whether the 'gateway effect' applies to humans. Over the past 60 years, the prevalence of smoking among young men in the US and UK declined about 4-fold. If nicotine use leads to increased use of cocaine and other drugs, the use of other drugs should decline as well. There is no sign of that.


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    1. On 2014 Dec 15, Ivan Shatsky commented:

      General comment: The phenomenon studied in this paper is very exciting. I read the article with a great interest. Unfortunately, I regret to say that the underlying mechanism remained uncovered. Although I agree that the authors identified some curious structures within the 5’UTRs of HOXA mRNAs which might be implicated in the regulation of these mRNAs by RPL38, I did not find sufficient evidence for existence of IRES-elements in these mRNAs. As in numerous other similar investigations, to identify IRES-elements the authors employed the method of DNA bicistronic constructs, the approach that had been repeatedly shown to be associated with almost unavoidable artifacts (see Jackson Cold Spring Harb Perspect Biol. 2013 Feb 1;5(2); Lemp et al. Nucleic Acids Res. 2012 Aug;40(15):7280-90.). And I suspect this paper is not free of those artifacts either (see below). Several crucial control experiments necessary to support or to exclude the IRES-mediated mechanism have been recently described (for references see Shatsky et al. Mol Cells. 2010 Oct; 30(4):285-93). One of them, for instance, is the ratio of translational activities for m7G capped versus uncapped (A-capped) monocistronic constructs. This value estimates contribution of the cap to the translational potential of a 5’UTR under selected conditions. If this contribution is very high (as is the case of cap-dependent mRNAs) one may exclude the presence of a true IRES. I think that this and other obligatory controls are feasible to perform with cells C3H10T1/2 used in this paper but they were not done.

      Some specific points:

      1. The authors regard the cap-independent and IRES-dependent modes of translation initiation as synonymous mechanisms and support this notion with reference 21. I should stress that not all specialists in eukaryotic translation would share this opinion since nobody has ever shown that a 5’end dependent translation initiation cannot be regulated by specific structures within the respective 5' UTR. The opposite has recently been demonstrated (Terenin et al. Nucleic Acids Res. 2013 Feb 1;41(3):1807-16.)
      2. When listing examples of cellular IRESs identified to date (second paragraph), the authors mention c-myc, Apaf-1, XIAP. To the best of my knowledge, these cellular IRESs have been disproved (Andreev et al. Nucleic Acids Res. 2009 Oct;37(18):6135-47; Bert et al. RNA. 2006 Jun;12(6):1074-83; Baranick et al. Proc Natl Acad Sci U S A. 2008 Mar 25;105(12):4733-8; van Eden et al. RNA. 2004 Apr;10(4):720-30); Lemp et al. Nucleic Acids Res. 2012 Aug;40(15):7280-90. )
      3. “Extended data Figure 1a” raises a great concern: the HCV IRES should not be used as a normalizing construct for testing bicistronic DNAs since the HCV IRES has been reported to harbor a cryptic promoter (Dumas, E. et al. 2003 Nucleic Acids Res. 31 (4): 1275-1281) and hence may produce capped monocistronic mRNAs . By the way, among viral IRESs characterized to date the HCV IRES is regarded as one of the weakest.
      4. The control test with Rluc shRNA (Extended data Figure 1 b,c) strongly suggests that some significant amount of monocistronic (and therefore capped) Fluc mRNAs is present in transfected cells since the residual Fluc activity after RNA interference is too high. This may also be the case for the control bicistronic mRNA containing the HCV IRES (see point 3). Otherwise, the pictures 1b and 1c must be similar. At least, in the analogous test performed in our lab, the Rluc and Fluc activities fall down to the similar background levels (Fig. 2D in Dmitriev et al. Mol Cell Biol. 2007 Jul;27(13):4685-97).
      5. The authors suggest that the IRES elements are mostly confined within ~300 nts proximal to the start codon. As a support to this conclusion, they note that some of HOXA mRNAs possess a 5’ UTR of that size. If so, why the activity of HOXA9 construct 944-1266 is much lower than that for the full length 5’UTR (Fig. 1d)?<br>
      6. “Extended Figure 1d”. This control is useless. It only shows that the bicistronic mRNA of the expected size is present in transfected cells but unable to show the presence of monocistronic mRNAs starting within the intercistronic region. The corresponding bands won’t be seen.
      7. On the base of pull-down experiments the authors claim that 80S ribosomes are specifically formed on their IRES-elements. The problem is that they use 10mM of magnesium in these expts, i.e. the concentration at which the assembly of translation initiation complexes in mammalian systems should not occur.
      8. The mode of action of TIE element looks absolutely puzzling. It is even difficult to imagine any mechanism for its operation. My question: is it specific to these particular cells?


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    1. On 2015 Feb 06, Ryan Radecki commented:

      Post-publication commentary: "Social Media in Medicine – Useless!"

      Or, might it be how you use it that matters?

      This is a brief report from the journal Circulation, regarding a self-assessment of their social media strategy. The editors of the journal performed a prospective, block-randomization of published articles to either social media promotion on Facebook and Twitter, or no promotion, and compared 30-day website page views for each article. 121 articles were randomized to social media and 122 to control, and were generally evenly balanced between article types.

      And, the answer – unfortunately, for their 3-person associate editor team – is: no difference....

      http://www.emlitofnote.com/2014/11/social-media-in-medicine-useless.html


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    1. On 2014 Dec 30, Kausik Datta commented:

      To add to Hilda Bastian's informative comment, the press release mentions the misleading statement not only in the title, but also in the first paragraph - stating definitively: "The study, published Nov. 17 by Proceedings of the National Academy of Sciences, shows that triclosan causes liver fibrosis and cancer in laboratory mice through molecular mechanisms that are also relevant in humans." (Emphasis mine.)

      This is, at best, irresponsible journalism (and at worst, a terrible disservice to people living with cancer). What seems particularly galling is the fact that this sacrifice of scientific accuracy at the altar of needless sensationalism in the press release was perpetrated by none other than the University (UCSD) at which the work was done. This brings to mind once again the age-old tussle in science communication, between science and journalism.

      At the same time, the authors cannot deflect the blame completely, especially since the lead author, quoted in the Press Release, didn't seem to emphasize at all the dosage effect of Triclosan administration and exposure route - which is rather odd, given that the Triclosan was either fed to the mice or injected directly into their peritoneal cavity at a high enough amount, none of which would apply to humans.

      I hope the authors pay heed to the most germane points raised by Hilda about the further inclusion of the data; I'd be most interested in the actual experimental outcomes.


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    2. On 2014 Nov 21, Hilda Bastian commented:

      The title and abstract of this article focuses on the positive finding in tumor promotion, without emphasizing that the findings were negative on causation, in a way that is clearly accessible for non-specialist readers. This is of particular importance, as a university press release issued for this study was headed with this misleading statement: "The dirty side of soap: Triclosan, a common antimicrobial in personal hygiene products, causes liver fibrosis and cancer in mice." This encouraged unwarranted alarm in the community (which I discuss further in this blog post).

      A 2010 inventory of animal and clinical studies of triclosan safety (Rodricks JV, 2010) found that oncogenicity studies to that point had not found cancer-related increases in any species, except for liver cancer in mice. Without pre-registration of studies on this question, we are unaware of what the outcomes have been for all oncogenicity studies on this substance, and thus whether there is publication bias.

      Further areas of uncertainty relate to the experiments here. The article does not report sufficient data and methodological information to enable adequate assessment of the level of uncertainty associated with the experiments (see the NIH's Proposed Principles and Guidelines for Reporting Preclinical Research). It would be helpful if the authors took the opportunity to include key data here, specifically:

      • how the sample size was determined;
      • the inclusion/exclusion criteria;
      • exact data on the experiments' results (including confidence intervals);
      • whether or not allocation of mice to the groups was random, and if so, details of the method of randomization (including whether or not there was blinding);
      • whether there was blinding in outcome assessment.


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    1. On 2014 Nov 20, Neven Patrick commented:

      Looks like estrogen removal reduced the proliferation significantly and probably the tumor has high ER mRNA score and very sensitive to estrogen deprivation. My thought is to regard this tumor as luminal A. Also important would be to check the probability of the class assignment by PAM50. Some cases surely will have lower probability than others and this case might be one of those. Because I presume single case PAM50 algorithm based on distance from centroid of model cases of intrinsic subtype will be forcing the class assignment for the cases which in the clustering would be gray zone cases. Does Prosigna report provide such QC measure? Soon Paik

      Truly fascinating (and not so simple) questions! To my knowledge this has not been studied, and I agree that removal of estrogen could potentially alter the proliferative rate of the tumor (and proliferation is a dominant aspect of most MGS to date). For this patient I would base treatment on the higher risk result. Kathy Albain

      If one measures Ki67 on the core it will be higher because pt is on E but if you measure it again 2 wks later on the surgical specimen it will be lower and won't agree with that done on the core. I would be surprised if that is not true. C.Kent Osborne

      Just saw a patient with an ER+ cancer, ki67 30% on core biopsy. Stopped HRT. Had surgery for T2N0 IDC and oncotype 14. Oncologist recommended chemo due to Ki67. Repeated ki67 on surgical sample and it was less than 5%. There is clearly an education opportunity here. Presumably the lower ki67 after stopping HRT is predicative of outcome and impact of hormone therapy. Interesting.<br> Hope S. Rugo


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    1. On 2015 Jan 05, NephJC - Nephrology Journal Club commented:

      This study was discussed on Dec 2nd 2014 in the open online nephrology journal club, #NephJC, on twitter (along with a related article).

      Introductory comments, written by Eoin O'Sullivan, are available at the NephJC website and cross-posted at the Renal Fellow Network blog.

      The discussion was quite intense, with more than 50 participants, including nephrologists, emergency medicine physicians, fellows and residents as also two of the authors, Bhupinder Singh and Edgar Lerma.

      A transcript and a curated (i.e. Storified) version of the tweetchat are available from the NephJC website.

      The highlights of the tweetchat were:

      • There is considerable interest in a drug such as ZS-9, given the incidence of hyperkalemia, both acute and chronic, sometimes resulting in the need to stop ACE-inhibitors and ARBs in CKD patients.

      • There was considerable discussion about the choice of placebo (as against sodium polystyrene sultanate, or diuretics and/or low potassium diet) as a comparator; the authors provided insight that this was mainly to comply with FDA requirements.

      • Though the results of the trial show that ZS-9 as studied was effective in lowering potassium levels, more information about the differential incidence of edema as also the details of diuretic use in both groups was sought.

      Overall, though there is considerable enthusiasm about the availability of new agents for management of hyperkalemia, considerations of safety, cost and data from more studies will determine how widely this drug will be used once licensed.

      Interested individuals can track and join in the conversation by following @NephJC or #NephJC, or visit the webpage at NephJC.com.


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    1. On 2016 Apr 20, Jennifer S Walsh commented:

      It wasn't possible to get perfect matching for all the factors, so it was done in order of: gender, age, height, postcode and smoking. Because smoking was the lowest priority, there were a few pairs who were matched on the other factors but not on smoking. The number of smokers was low overall, and we don't think the imperfect matches for smoking had any influence on the study results.


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    2. On 2016 Apr 15, Jose M. Moran commented:

      There is an issue that needs to be addressed. Controls were recruited to be individually matched to an obese participant by sex, age (±3 years), height (±5 cm), postcode and smoking status (current smoker or nonsmoker). If controls were matched 1:1 by the smoking status, how it is possible that the percentage of current smokers differs between normal and obese subjects across all the age groups (except in men aged 25-45 years n=6)?


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    1. On 2016 Oct 03, Morten Oksvold commented:

      Please note that after an investigation at the University of Cologne, six articles where T. Wenz figures as first or senior author were found to contain questionable data due to scientific misconduct. This article is one of these six articles.

      The conclusion from the report was ready June 28, 2016, please see the link (in German):

      http://www.portal.uni-koeln.de/9015.html?&tx_news_pi1[news]=4335&tx_news_pi1[controller]=News&tx_news_pi1[action]=detail&cHash=1deb8399d7f796d65ca9f6ae4764a1ce


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    1. On 2014 Dec 04, David Keller commented:

      Cause and effect cannot be distinguished in the observed associations

      Dopamine levels are reduced in the brains of patients with Parkinson's disease (PD). Dopamine inhibits the secretion of prolactin, and prolactin, in turn, reduces the activity of the steroid sex hormones (estrogen, testosterone, etc.) Thus, untreated PD patients should have low brain dopamine levels, high prolactin levels and thus low sex steroid hormone levels. These hormone actions are well-documented in physiology texts.

      The next clinical scenario to consider is the effect of treating PD with levodopa, which is metabolized to dopamine in the brain. Clearly, brain dopamine levels will rise, driving down prolactin levels, which, in turn, allows an increase in sex steroid levels, ameliorating, to a variable degree, the hypogonadism caused by untreated PD.

      To what degree does the dose of levodopa, taken in amounts sufficient to control the movement disorder symptoms of PD, also treat the hypogonadism caused by PD? This question is not addressed in the abstract.

      The authors conclude that lower sex steroid levels and higher prolactin levels "may result in a bigger susceptibility to the disease in men." This observational study cannot possibly prove the cause-and-effect mechanism implied in that statement. The observed associations are explained equally well by the opposite conclusion: that PD causes men to have lower dopamine levels, higher prolactin levels and consequently lower sex steroid levels (hypogonadism), in other words, that hypogonadism is an effect of PD, not a cause. It would require a randomized, controlled interventional study in which hypogonadal PD patients were repleted with administered exogenous sex steroids to prove that hypogonadism is a cause, rather than just an effect, of PD.


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    1. On 2014 Dec 19, Scott Federhen commented:

      I am Scott Federhen, author of this article, and would like to report some aspects of our genomes from type that were discovered too late to include in the manuscript. A visual inspection of our k-mer tree revealed two genomes from type for Bacillus subtilis subsp. spizizenii that are placed quite distantly from each other.

      The average nucleotide identity (ANI) statistics from the alignments of the type genomes from the relevant subspecies of Bacillus subtilis are as follows:

      96.7997 CP002905 ADGS01 89.7316 94.8698 – spizizenii vs. spizizenii

      94.6427 CP002905 AMXN01 89.4248 86.6265 – spizizenii vs. inaquosorum

      93.2854 CP002905 AL009126 88.7053 88.4756 – spizizenii vs. subtilis

      89.7% of CP002905 aligns with 94.9% of ADGS01, and the parts that align share 96.8% average nucleotide identity. These two genomes a likely to be from the same species, but probably not from the same subspecies - and certainly not from co-identical strains.

      To examine this problem systematically, we looked for all of the cases where we had more then one genome from type from the same species (or subspecies) and sorted them by pairwise ANI. These were usually from different culture collections and often sequenced in different labs. 274 pairwise combinations break down like this:

      4 pairs of genomes < 90% identical.

      5 pairs of genomes 96% - 99% identical.

      8 pairs of genomes 99% - 99.9% identical.

      112 pairs of genomes 99.9% - 99.99% identical.

      135 pairs of genomes 99.99% - 99.999% identical.

      10 pairs of genomes > 99.999% identical

      This is a wide range for genomes from strains that are supposed to be co-identical. The four most diverse pairs are likely to be from different species. The problem could lie in many places - the annotation in the sequence entries, a strain mixup in the sequencing lab, or a contamination, misannotation or misidentification in the culture collection. We are working with submitters and culture collections to resolve the most egregious discrepancies and improve the reliability of our subset of genomes and sequences from type. At some point the community is going to have to come to a consensus as to what constitutes identity between co-identical strains.

      We look forward to the day when every described species of prokaryote has a complete genome sequence, and a genome is included with every new species description. At that point it would be useful for each culture collection holding strains from type to sequence at least a low-coverage genome to verify the identity of the strain.


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    1. On 2015 Feb 26, Harri Hemila commented:

      Missing contradictory findings and other problems in Curtis AJ, 2014

      Curtis AJ, 2014 state in their abstract that “The evidence from pooled analysis of 18 randomised controlled trials undertaken in apparently healthy people shows no effect of vitamin E supplementation at a dose of 23-800 IU/day on all-cause mortality.” This conclusion was based on the pooling of results from 18 RCTs that obtained RR = 1.01 (95% CI: 0.97 to 1.05).

      In their calculation of the average effect of vitamin E from the 18 studies, Curtis (2014) assume that there exists an overall uniform effect for all of those 18 RCTs, which can be estimated by pooling their findings. However, a subgroup analysis of the ATBC Study (1994) refutes the notion that the effect of vitamin E is uniform for all people. The combination of age and dietary vitamin C in the subgroup analysis modified the effect of vitamin E, which provides very strong evidence of heterogeneity over 6 subgroups (P = 0.0005) Hemilä H, 2009. Such heterogeneity refutes the assumption of a uniform effect in pooling the findings of the 18 RCTs by Curtis (2014).

      Curtis AJ, 2014 also state “Subgroup analyses by ... duration of exposure ... showed no association with all-cause mortality.” However, the effect of time should not be analyzed by comparing RCTs at the study level, some of the RCTs being long in duration while the others being short in duration. In the ATBC Study, harm from vitamin E in the young participants was seen after 3.3 years of supplementation. Longer vitamin E supplementation increased mortality by 38% (17% to 63%), whereas vitamin E had no effect on mortality over the earlier period, see Hemilä H, 2009. This finding of a time-dependent effect modification refutes the claim that the duration of vitamin E supplementation does not modify the effects of the vitamin with regard to all-cause mortality. Comparing RCTs on vitamin E by the mean durations of the RCTs, ie study-level analysis, cannot capture changes in the vitamin E effect after lag periods. Instead the analysis of time-dependent effect modification requires individual-level analysis.

      Ecological fallacy occurs when mean data about a group is used to impute identical values for all individuals of the group. Thus, the assumption by Curtis AJ, 2014 that the calculated average effect of vitamin E on mortality for the 18 RCTs (ie RR = 1.01) is valid for all participants in these 18 studies, or for other individuals in the community, is an example of ecological fallacy. The conclusion by Curtis AJ, 2014 that “duration of exposure ... showed no association with all-cause mortality” is another example of ecological fallacy.

      We do not know how far the heterogeneity of the ATBC Study can be generalized. The participants in that study were middle-aged males, who were aged 50-69 years at the start of the trial in the 1980s, which indicates that they were born before WW-II. In addition, all were smokers and lived in Finland. We do not know if similar effect modification occurs in other populations. Nevertheless, the heterogeneity found in this particular cohort refutes the notion that there might be a universal vitamin E effect on mortality that would be valid for all groups of people. Highly significant heterogeneity was also found in the effect of vitamin E on pneumonia incidence in Hemilä H, 2011 and on the incidence of the common cold in Hemilä H, 2006. Thus the evidence of heterogeneity of the vitamin E effect is not restricted to overall mortality but exists to other outcomes as well.

      Furthermore, in the Table 1 of Curtis AJ, 2014 it is stated that the “study quality” of the ATBC Study (1994) was “medium”. As a justification for this classification, in Appendix 2 (“quality of included studies”) Curtis AJ, 2014 inserted question marks next to “blinding of personnel” and “blinding of participants” and a cross (to indicate high risk of bias) to “blinding of outcome assessment”.

      The ATBC Study (1994), Alpha-Tocopherol, Beta Carotene Cancer Prevention Study Group., 1994, reported that “Participants and all study staff involved in the ascertainment of end points and the assignment of final diagnoses remained blinded to the participants' treatment assignments throughout the trial” (p. 1030). The same report also stated that “Deaths (n=3570) were identified from the National Death Registry, a branch of Statistics Finland” (p. 1030), which clearly indicates that the deaths in the ATBC study were recorded by an organization that had nothing to do with the administration of the tablets. Thus, the claims by Curtis (2014) about the blinding of participants and personnel in their Appendix 2 are inconsistent with the ATBC Study (1994) report.

      Transparency in systematic reviews is important, so that the reader is correctly informed what the basis for the quality assessments is. Curtis AJ, 2014 do not give any explanations about why they dismiss the descriptions about blinding in the ATBC Study (1994) report. Therefore the readers are misled about the quality of the study that has the greatest weight in Fig. 2 of Curtis (2014).

      Finally, the ATBC Study (1994) is wrongly cited in Curtis AJ, 2014. They write Virtamo (1998) in Fig. 2 ,Virtamo (2006) in Appendix 2, and Virtamo (2003) in the reference section. All of these three years are wrong. The ATBC Study was actually published in 1994, with the PubMed record Alpha-Tocopherol, Beta Carotene Cancer Prevention Study Group., 1994 (the correct year and reference). Virtamo (2003), which is listed in the reference section, does exist but it is a post-intervention follow-up report of the trial and not the correct reference for the main results of the ATBC Study (1994).


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    1. On 2017 Jan 09, Kausik Datta commented:

      I came to this paper after reading about Dr. Hadiyah-Nicole Green on Social Media. Much plaudits to Dr. Green and her team. The principle - conversion of near Infra Red light to thermal energy by Gold nanorods - is exciting and full of possibilities, and the proof-of-concept is well-demonstrated both in vitro and in vivo. The question that I had about the AuNR-only group in Figure 2D is answered in the discussion, although I'd have loved to see confirmation of the visible light PTE hypothesis: because if visible light is able to show similar effects on AuNRs, it might make their therapeutic spectrum broader - but bring in problems of specificity as well. In cancer therapeutics, specificity/focus of treatment is an important issue in respect of preserving good cells and destroying rogue, tumorous ones. Ideally, visible or any other light should have minimal effect, while NIR should have maximal on rousing the AuNRs, so to speak.

      Also in that respect, while intratumoral delivery of AuNRs takes care of stationary tumors, perhaps an antibody/ligand-based mechanism in conjunction with AuNRs may in future be able to target metastatic tumors as well? This is excellent work that I shall be much interested to follow. (I note that this paper is from 2014. Perhaps Dr. Green would be kind enough to provide a status update?)


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    1. On 2015 Mar 03, Dita Gratzinger commented:

      We congratulate the authors on a comprehensive overview of this very complex and evolving field of research. Many of the crucial studies represent in vitro and mouse model research; we are characterizing the state of the intact bone marrow stroma in myelodysplastic syndromes. The authors state that

      "Multiple data have shown that osteoprogenitors—MSPCs—exhibit normal morphology and frequency in the bone marrow of MDS patients, as well as undisturbed osteoblastic, adipocytic and chondrocytic differentiation potential in vitro."

      We have recently published data, not available at the time this review was written, regarding the architecture and extent of the CD271+ mesenchymal stromal cell compartment in intact human bone marrow core biopsies Johnson RC, 2014, and in fact demonstrate an increase in the density of this compartment in higher grade MDS as compared to lower grade MDS and marrow from similarly aged cytopenic patients. We also found an association of high CD271+ mesenchymal stromal cell density with shorter overall survival among patients with MDS, independent of IPSS-R and history of transfusion. We acknowledge that it is not clear whether functionally described osteoprogenitors correspond to all or a subset of CD271+ mesenchymal stromal cells; however, as cited in your review, we have previously shown Flores-Figueroa E, 2012 that CD271+ mesenchymal stromal cells express CXCL12 and arborize extensively within marrow, in association with marrow vasculature, and are intimately associated with the majority of CD34+ hematopoietic stem/progenitor cells in intact human marrow, and are thus good candidates to represent a key functional component of the human bone marrow hematopoietic progenitor/stem cell niche.


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    1. On 2014 Nov 14, Hilda Bastian commented:

      Very useful data on an important issue, given the high proportion of the population using contact lenses (Swanson MW, 2012). On the issue of the level of individual risk, readers might find a review of large-scale epidemiological studies helpful (Stapleton F, 2013).

      The authors stress the importance of good lens hygiene to reduce the risk of infection. That's a critical issue, and people may well over-estimate the adequacy of their own lens care (Bui TH, 2010). Given the increased risk of extended wear (rising from 2-4 per 10,000 for daily use to about 20 for extended wear Stapleton F, 2013), users being better informed about reduced wear as a way of lessening risks may also help (covered along with social and historical aspects in this blog post.)


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    1. On 2014 Nov 24, Alexis Clapin commented:

      Congratulation for your important work. In table 1, you state that the first approache to addressing attrition bias is intend-to treat analysis. Intend to treat analysis includes all data but when a clinical trial suffers from attrition bias, patients followed up for a longer duration are favouring one of the compared product. For a lot of outcome criteria, a longer duration means a more important impact on the criteria. Consequently, the intend to treat analysis is a biased evaluation of the difference between groups. An example of the impact of attrition bias on the intend-to-treat analysis is given in this article http://www.ncbi.nlm.nih.gov/pubmed/23662092. Without complete data, the best way to evaluate attrition bias is the comparison of intend-to-treat analysis and per-protocol analysis. If the per-protocol analysis provides us with a "better" result than intend-to-treat analysis, it means that patients followed up for the longer duration are favouring one of the compared product. This comparison should be done for all truncated trials. Unfortunately, it is not the case and a lot of clinical trials are truncated ; almost all based on survival analysis. To conclude, if intend-to-treat analysis is the only performed analysis, it is a good way to mask an attrition bias.

      For french readers : a more complete evaluation of the advantages of performing both analysis : http://www.etudes-et-biais.com/per-protocole-ou-intention-de-traiter-les-deux-svp/


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    1. On 2013 Oct 25, DAVID SANDERS commented:

      From abstract from Kikuchi A, 1989

      "In this paper, two proteins stimulating the GTPase activity of smg p21 are partially purified from bovine brain cytosol. These proteins, designated as smg p21 GTPase-activating protein (GAP) 1 and 2, are separated from a c-ras p21 GAP described previously by column chromatographies. smg p21 GAP1 and -2 stimulate the GTPase activity of only smg p21 but not that of c-Ha-ras p21 or the rho and smg-25A GTP-binding proteins. The Mr values of smg p21 GAP1 and -2 are estimated to be 250-400 x 10(3) and 80-100 x 10(3) by gel filtration and sucrose density gradient ultracentrifugation, respectively. The activity of smg p21 GAP1 and -2 is killed by tryptic digestion or heat boiling. These results indicate that bovine brain contains two smg p21 GAPs in addition to c-ras p21 GAP.


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    1. On 2014 Nov 24, Guillaume Filion commented:

      This article is one of the "CISCOM meta-analyses", which are very similar papers written by different authors. For more information about the CISCOM meta-analyses, check the blog post "A flurry of copycast on PubMed" at the following link http://blog.thegrandlocus.com/2014/10/a-flurry-of-copycats-on-pubmed


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    1. On 2015 Jul 23, thomas samaras commented:

      Over 80 diverse populations show that weight increases as the cube of height increase. For example, the publication Advancedata, US Department of health, education, and welfare, Nov 19, 1976, Table 7 provided data for 18-24 year olds which allowed the following calculations.

      Males: 1971 vs. 1960: (69.7"/68.7")cubed x 158 lb = 165 lb (predicted by cubed law) Actual weight given for taller cohort = 165 lb

      For females, the results were 130 lb predicted and 132 lb actual.

      Another publication, Secular growth and its harmful ramifications, 2002, confirmed the height cubed law (not height squared or BMI law)for five populations (Table 1):

      Harvard male entrants (1958 vs. 1930) Wellesley female entrants (1958 vs. 1930) Malina's child data (1958 vs. 1934) Swedish males (n= 488,732) (1971 vs. 1960) US population (18-74 years)(1971 vs. 1960)

      A number of more recent studies provide data that support the Ponderal Index or height cubed law.


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    1. On 2015 Mar 11, IRWIN FEINBERG commented:

      Crawley et al 1 state that there have been few longitudinal studies of sleep/wake timing across adolescence. They fail to take note of our findings in a ten-year longitudinal study of 93 subjects aged 6-18 years. Sleep EEG was recorded twice yearly on habitual school-night schedules in subjects aged 6-18 years. In addition, weekend recordings with extended time in bed and a follow-up night, were obtained from subjects 9-18 years. Results published thus far could have added perspective to the findings of Cowley et al. In addition to defining the trajectories of NREM delta and theta EEG power 2, 3, their within-night dynamics 4, and their relations to puberty 5 and daytime sleepiness 6, we documented changes in NREM and REM bed schedules and sleep durations 7 that bear directly on the findings of Crowley et al. Our study demonstrated that school-night time in bed decreased by 13 min/year between ages 9-18 yrs (p<0.0001). From an average bedtime of 9:15 PM at age 9 yrs, bedtimes advanced by 13 min/year (p<0.0001), whereas rise times did not change (p=0.11). Sleep latency did not change (p=0.70), but sleep efficiency increased over this age range (p<0.0001). The net result was that total sleep time (TST) decreased by 10 min/yr from 515 min at age 9 to xx min at age 18 (p<0.0001). This TST reduction was not produced by shorter REM and NREM durations, as would be expected if it was the result of sleep deprivation due to restricted time in bed. Instead, TST declined because of a selective reduction of NREM sleep, which declined by 12 min/yr (p<0.0001). REM sleep durations actually increased significantly by 2 min/yr (p<0.0001). This pattern of change cannot be attributed to a phase advance. We interpret it, along with the massive decline in slow wave EEG power, as a manifestation of brain maturation driven by synaptic elimination. In our model, synaptic elimination during adolescence decreases the intensity of waking brain activity (shown also by declining cerebral metabolic rate 8) which decreases the need for NREM dependent recuperation of plastic neuronal systems.

      1. Crowley SJ, Van Reen E, LeBourgeois MK, et al. A longitudinal assessment of sleep timing, circadian phase, and phase angle of entrainment across human adolescence. PLoS One 2014;9:e112199.
      2. Campbell IG, Feinberg I. Longitudinal trajectories of non-rapid eye movement delta and theta EEG as indicators of adolescent brain maturation. Proc Natl Acad Sci U S A 2009;106:5177-80.
      3. Feinberg I, Campbell IG. Longitudinal sleep EEG trajectories indicate complex patterns of adolescent brain maturation. Am J Physiol Regul Integr Comp Physiol 2013;304:R296-303.
      4. Campbell IG, Darchia N, Higgins LM, et al. Adolescent changes in homeostatic regulation of EEG activity in the delta and theta frequency bands during non-rapid eye movement sleep. Sleep 2011;34:83-91.
      5. Campbell IG, Grimm KJ, de Bie E, Feinberg I. Sex, puberty, and the timing of sleep EEG measured adolescent brain maturation. Proc Natl Acad Sci U S A 2012;109:5740-3.
      6. Campbell IG, Higgins LM, Trinidad JM, Richardson P, Feinberg I. The increase in longitudinally measured sleepiness across adolescence is related to the maturational decline in low-frequency EEG power. Sleep 2007;30:1677-87.
      7. Feinberg I, Davis NM, de Bie E, Grimm KJ, Campbell IG. The maturational trajectories of NREM and REM sleep durations differ across adolescence on both school-night and extended sleep. Am J Physiol Regul Integr Comp Physiol 2012;302:R533-R40.
      8. Chugani HT, Phelps ME, Mazziotta JC. Positron emission tomography study of human brain functional development. Ann Neurol 1987;22:487-97.


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    1. On 2016 Aug 23, Ben Goldacre commented:

      This trial has the wrong trial registry ID associated with it on PubMed: both in the XML on PubMed, and in the originating journal article. The ID given is NCT0150177. We believe the correct ID, which we have found by hand searching, is NCT01501773.

      This comment is being posted as part of the OpenTrials.net project<sup>[1]</sup> , an open database threading together all publicly accessible documents and data on each trial, globally. In the course of creating the database, and matching documents and data sources about trials from different locations, we have identified various anomalies in datasets such as PubMed, and in published papers. Alongside documenting the prevalence of problems, we are also attempting to correct these errors and anomalies wherever possible, by feeding back to the originators. We have corrected this data in the OpenTrials.net database; we hope that this trial’s text and metadata can also be corrected at source, in PubMed and in the accompanying paper.

      Many thanks,

      Jessica Fleminger, Ben Goldacre*

      [1] Goldacre, B., Gray, J., 2016. OpenTrials: towards a collaborative open database of all available information on all clinical trials. Trials 17. doi:10.1186/s13063-016-1290-8 PMID: 27056367

      * Dr Ben Goldacre BA MA MSc MBBS MRCPsych<br> Senior Clinical Research Fellow<br> ben.goldacre@phc.ox.ac.uk<br> www.ebmDataLab.net<br> Centre for Evidence Based Medicine<br> Department of Primary Care Health Sciences<br> University of Oxford<br> Radcliffe Observatory Quarter<br> Woodstock Road<br> Oxford OX2 6GG


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    1. On 2015 Feb 10, Pieter-Jan Volders commented:

      At the time of submission, we were unaware of a specific RefSeq lncRNA subset. As a result, we initially used the NR_* records larger than 200 nucleotides. When dr. Kim D. Pruitt contacted us regarding this issue, we repeated the analysis for the suggested RefSeq subset. This subset contains 4774 transcripts and was obtained through the UCSC table browser. As expected, the percentage of transcripts passing the PhyloCSF cutoff has decreased from 48% to 14% of the RefSeq subset. The online manuscript was updated and the current Figure 3 (online as of January 15, 2015) represents these new results. Additionally, LNCipedia.org was updated as well, and the RefSeq records that do not represent lncRNAs were removed from the database version 3.1.

      It is worth noting that we could not find any information on the keyword that was used in the query suggested by dr. Kimm D. Pruit (biomolncrnalncrna), neither on the RefSeq website, nor in the cited manuscript. It is unclear to us how many researchers are aware of this and we would like to suggest to RefSeq to indicate this subset on their website as it is of great value to the lncRNA research community.


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    2. On 2014 Dec 03, Kim D Pruitt commented:

      The RefSeq results that are presented in Figure 3 do not accurately reflect the high quality of the RefSeq lncRNA dataset.

      The article does not describe how this dataset was defined but the authors kindly provided this information as well as a file listing all of the RefSeq accessions and PhyloCSF results. The authors’ definition of RefSeq lncRNA was too simple as it was primarily based on the RefSeq accession prefix (‘NR_’). However, this accession prefix is used by the RefSeq project for several types of noncoding transcripts (PMID:18927115). Roughly 50% of the RefSeq dataset analyzed represent transcribed pseudogenes or noncoding transcripts for protein-coding genes.


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    1. On 2015 Sep 08, CREBP Journal Club commented:

      This study gives an excellent insight into GPs’ experiences of two contrasting interventions – training in communication skills (including use of a patient booklet) and the use of a point of care test (CRP). We found it encouraging that the clinicians reported gaining new knowledge from the interventions. Information, such as expected duration of illness and the benefits and harms of antibiotic treatment of acute respiratory infections should preferably be part of any intervention aimed at either GPs or patients. Both interventions achieved important reductions in antibiotic prescribing for acute respiratory infections – and combining the interventions was associated with an even greater reduction(1). The group discussed if future interventions should be multi-faceted. Anthierens et al. found that the GPs reported that the two interventions were complementary and often used for different situations, i.e. the CRP test when there was uncertainty about the severity of the infection, and the communication skills/booklet when an explanation was required. However, it was mentioned that in some countries, such as Australia, the CRP test is still not routinely used as a point of care test in general practice. The group found the information in the booklet very useful. However, the sections about “Helping your immune system fight infection” and “How you can care for your cough” were debated. E.g. a Cochrane Review on Echinacea products did not find any benefits for treating colds(2) and also in the booklet it is stated that the advice on fluids, rest and stress is based on evidence about how the immune system works. Preferably, information used in interventions to enhance the quality of antibiotic prescribing for acute respiratory infections should be based on solid evidence about the group of patients being examined – i.e. in this case patients with acute respiratory infections. In addition, high quality, primary care-based studies are needed to further explore alternatives such as probiotics, zinc and vitamin C and to develop and test new non-antibiotic treatments. See CREBP Journal Club for more information.

      References: (1) Little P, Stuart B, Francis N, et al. Effects of internet-based training on antibiotic prescribing rates for acute respiratory-tract infections: a multinational, cluster, randomised, factorial, controlled trial. Lancet 2013; 382(9899): 1175-82. (2) Karsch-Volk M, Barrett B, Kiefer D, Bauer R, Ardjomand-Woelkart K, Linde K. Echinacea for preventing and treating the common cold. The Cochrane database of systematic reviews 2014; 2: Cd000530.


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    1. On 2015 Feb 27, Geriatric Medicine Journal Club commented:

      This clinical trial of of Problem Adaptation Therapy (PATH) was critically appraised at the January 2015 Geriatric Medicine Journal Club (follow #GeriMedJC on Twitter). A transcript of the discussion can be found here: http://gerimedjc.blogspot.com/2015/01/gerimedjc-january-30-2015.html?spref=tw Highlights include the question of how feasible it is to deliver this type intervention in our current health care climate.


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    1. On 2015 Jan 05, NephJC - Nephrology Journal Club commented:

      This trial was discussed on Dec 16th and Dec 18th (in the first transatlantic version) in the open online nephrology journal club, #NephJC, on twitter. Introductory explanatory comments, written by Rheumatologist, Dr Paul Sufka, are available at the NephJC website, and Dr Sufka’s blog. It had more than 50 participants, including nephrologists, rheumatologists and nephrology and rheumatology fellows. Transcripts and curated (i.e. Storified) versions of the tweetchats are available from the NephJC website.

      The salient highlights of the discussion included:

      • The authors and the funding agency (the French Ministry of Health) should be commended for performing this trial to find better ways of minimizing relapses in ANCA associated vasculitis.

      • There was significant discussion around the Azathioprine dose chosen (tapered down to levels below that used in the CYCAZAREM trial in later part of this trial); as also the finding of early separation between arms, suggesting some patients in the control arm were azathioprine non-responders.

      • The Rituximab dosing strategy seemed quite astute, and was quite successful in reducing relapses without an increase in adverse events. The discussants looked forward to publication of more data from this trial, especially on B cell populations and ANCA titres, that could shed more light for a deeper understanding of the results.

      Overall, there was significant enthusiasm for using Rituximab in this setting, though the results of more trials, especially RITAZAREM and MAINRITSAN-2 are now keenly awaited.

      Interested individuals can track and join in the conversation by following @NephJC or #NephJC, or visit the webpage at NephJC.com.


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    1. On 2014 Nov 12, KEVIN BLACK commented:

      I think the effects of levodopa itself on brain activity may be of interest when interpreting the effects of levodopa on movement-related brain activity. Examples from my colleagues include the 4 following articles: PubMed Central IDs PMC21757 and PMC1738560, doi: 10.1038/sj.npp.1300632, and doi: 10.1006/exnr.2000.7522 .


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    1. On 2014 Nov 19, David Keller commented:

      A landmark paper with important implications for melanoma patients

      The results obtained by combining high-dose ipilimumab (10 mg/kg) with GM-CSF (sargramostim) are remarkable. The combination increased median overall survival by 4.8 months compared with high-dose ipilimumab alone, an increase of over 37%, and the combination also reduced the rate of serious adverse events significantly compared with high-dose ipilimumab monotherapy. Patients with advanced melanoma and poor response to existing treatments will want to discuss these results with their oncologists, particularly since GM-CSF is currently available in the U.S.

      Since GM-CSF is already approved for other indications, there will be great pressure on oncologists to prescribe ipilimumab in combination with GM-CSF on the basis of this study, particularly for patients whose tumor burden worsens despite approved therapy. Questions which will be encountered include:

      1) Would the pairing of GM-CSF with the approved dose of ipilimumab (3 mg/kg) have similar benefits, despite the fact that the ipilimumab dose used in the study was more than 3 times larger than the approved dose?

      2) Given the reduction in toxicity of the combination compared with ipilimumab monotherapy, can the approved dose of ipilimumab be safely tripled to 10 mg/kg if used in combination with GM-CSF?

      3) Is there any reason to believe that PD-1 checkpoint inhibitors, such as pembrolizumab, given in combination with GM-CSF, would not afford similar improvements in survival and adverse events?

      Patients with advanced melanoma who do not respond to currently approved treatments have little to lose. There is no reason to force these patients to wait for the results of confirmatory studies which they may have little hope of surviving to see published. Those that can be accommodated into clinical trials should be encouraged to participate, while the others should be offered the option of adding GM-CSF to their checkpoint inhibitor, if the latter fails to control their disease.


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    1. On 2014 Nov 17, Alexandre Chigaev commented:

      After the Nobel Prize in Physiology or Medicine in 1998 nitric oxide became a widely accepted signaling messenger. Studies of carbon monoxide are still largely limited to the fields of pollution, carbon monoxide poisoning, and vascular biology. This paper provides insight into possible role of carbon monoxide in the rapid regulation of cell adhesion that is crucial for cell mobilization and migration, ischemia-reperfusion injury and transplantation, immune response modulation and evasion of host defence employed by haemolytic pathogens.


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    1. On 2014 Nov 10, Serge Ahmed commented:

      This is an interesting series of experiments on choice between nicotine and sucrose in rats. In experiments 1, 3, 4 & 5, hungry rats were first trained to respond for sucrose or nicotine on alternate days before being provided with a choice between the two options. Overall, virtually all rats responded more for sucrose than for nicotine under a variety of choice conditions. Thus, all else being (approximately) equal, sucrose surpasses nicotine reward in rats!

      In experiment 2, rats were first trained to respond for nicotine before being provided with a choice between nicotine and sucrose. In this condition, about 50% of the rats responded more for nicotine than for sucrose, suggesting that “nicotine self-administration does not only occur in the absence of alternative reinforcement options”, at least in some rats.

      Though the results of experiment 2 are promising, they are difficult to interpret univocally. Experiment 2 lacks an important control group that controls for the difficulty in learning to respond for sucrose during choice testing. Briefly, rats were asked to respond on a novel lever under a random ratio 4 schedule of sucrose reinforcement, WITHOUT ANY PRIOR PROGRESSIVE TRAINING on this lever and after a long period of operant extinction. It is likely that many rats will fail to learn to respond for sucrose under these specific conditions, even in the absence of the opportunity to self-administer nicotine! Future research should resolve this important issue.


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    1. On 2014 Nov 07, Stephen Strum commented:

      I have looked at the full article in JCO and will re-read it, but it seems to me that the issue of salvage RT in the context of men with persistent PC after a local or local-regional therapy could be focused on additional key issues along with stronger advice. Issues that come to mind are the many papers that demonstrate that the first PSA post-RP taken at about 5-6 weeks post-op should use an ultrasensitive PSA. Papers by Doherty et al, Witherspoon and others showed that those with ultrasensitive values ≤ 0.01 had outstanding prognoses e.g., Only 2 patients with an undetectable prostate-specific antigen after radical retropubic prostatectomy biochemically relapsed (3%),compared to 47 relapses out of 61 patients (75%) who did not reach this level. More importantly, in 31 years of focused work caring for men with PC at all stages of illness, I rarely (< 1%) of the time see any diligence regarding use of nomograms and/or ANNs(artificial neural nets)done prior to initial therapy or at the time of so-called PSAR. Nomograms using PSAV + pathologic findings at RP are very helpful in risk assessment for men likely to be helped by salvage IMRT vs not.

      Another key issue not discussed in this paper is the RT treatment field and again, the use of nomograms, and ANNs to get a risk assessment for which patients are at risk for nodal spread. Too many men are being treated with RT fields that are not inclusive of where the disease is.

      To this end, I will say that ODAC blew it badly when they rejected a simple iron contrast nanoparticle (Combidex) to identify nodal mets at a level of sensitivity and specificity that is dramatically superior to the lousy sensitivity of CT abdomen and pelvis exams. The latter studies involve a half billion dollars globally on an annual basis but even more importantly MISdirect the use of RT and give the RadOnc and patient a false sense of where the active PC is.

      We have some wonderful tools that remain in the proverbial Al Gore "lockbox", often discussed in academic meetings but rarely used in the day in and day out care of men faced with prostate cancer.

      Stephen B. Strum, MD, FACP Member ASCO since 1973, AUA since 1998, ASTRO since 2002 PCRI (Prostate Cancer Research Institute) First Medical Director and Co-Founder 1997


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    1. On 2015 Jun 18, NephJC - Nephrology Journal Club commented:

      This guideline document was discussed on June 9th and 10th 2015 in the open online nephrology journal club, #NephJC, on twitter.

      Introductory comments are available at the NephJC website and blog. The discussion was very detailed, with more than 50 participants, including nephrologists, urologists and residents. Notable were nephrolithiasis experts, David Goldfarb and John Asplin.

      A transcript and a curated (i.e. Storified) version of the tweetchat are available at the NephJC website.

      The highlights of the tweetchat were:

      • Though the ACP follows stringent guideline development process, the absence of high quality data made the end result not quite useful for practical use, especially when compared to other competing publications, such as from the American Urological Association and the European Association of Urology. There was also concern that these guidelines may be (mis)used by third party payers to deny coverage for tests not endorsed in these guidelines.

      • From a physiological rationale, there was near unanimity that testing for stone composition is essential, especially in recurrent stone-formers. There was concern that the guideline developers were interpreting absence of evidence of benefit as evidence of absence of benefit.

      • Additional online comments that were thought to provide useful context to the discussion, written by Drs Coe, Goldfarb and Topf, are available here, here, here and here.

      Interested individuals can track and join in the conversation by following @NephJC or #NephJC, or visit the webpage at NephJC.com.


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    1. On 2014 Nov 28, Paolo Tieri commented:

      This article is one of the "Multi-omic Data Integration" Research Topic in Frontiers, which focuses on data integration approaches and methods of any type and extent, their application in understanding the pathogenesis of specific diseases or in identifying candidate biomarkers, in order to exploit the full benefit of multi-omic datasets and their intrinsic information content. For more information about multi-omic data integration check http://journal.frontiersin.org/ResearchTopic/2280


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    1. On 2014 Nov 28, Paolo Tieri commented:

      This article is part of the "Multi-omic Data Integration" Research Topic in Frontiers, which focuses on data integration approaches and methods of any type and extent, their application in understanding the pathogenesis of specific diseases or in identifying candidate biomarkers, in order to exploit the full benefit of multi-omic datasets and their intrinsic information content. For more information about multi-omic data integration check http://journal.frontiersin.org/ResearchTopic/2280


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    1. On 2014 Nov 28, Paolo Tieri commented:

      This article is part of the "Multi-omic Data Integration" Research Topic in Frontiers, which focuses on data integration approaches and methods of any type and extent, their application in understanding the pathogenesis of specific diseases or in identifying candidate biomarkers, in order to exploit the full benefit of multi-omic datasets and their intrinsic information content. For more information about multi-omic data integration check http://journal.frontiersin.org/ResearchTopic/2280


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    1. On 2014 Nov 28, Paolo Tieri commented:

      This article is part of the "Multi-omic Data Integration" Research Topic in Frontiers, which focuses on data integration approaches and methods of any type and extent, their application in understanding the pathogenesis of specific diseases or in identifying candidate biomarkers, in order to exploit the full benefit of multi-omic datasets and their intrinsic information content. For more information about multi-omic data integration check http://journal.frontiersin.org/ResearchTopic/2280


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    1. On 2014 Nov 28, Paolo Tieri commented:

      This article is one of the "Multi-omic Data Integration" Research Topic in Frontiers, which focuses on data integration approaches and methods of any type and extent, their application in understanding the pathogenesis of specific diseases or in identifying candidate biomarkers, in order to exploit the full benefit of multi-omic datasets and their intrinsic information content. For more information about multi-omic data integration check http://journal.frontiersin.org/ResearchTopic/2280


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    1. On 2015 Jan 05, NephJC - Nephrology Journal Club commented:

      This study was discussed on Dec 2nd 2014 in the open online nephrology journal club, #NephJC, on twitter (along with a related article: the HARMONIZE trial).

      Introductory comments, written by Eoin O'Sullivan, are available at the NephJC website and cross-posted at the Renal Fellow Network blog.

      The discussion was quite detailed, with more than 50 participants, including nephrologists,emergency medicine physicians, fellows and residents, with great insight provided by the senior author, David Juurlink.

      A transcript and a curated (i.e. Storified) version of the tweetchat are available from the NephJC website.

      The highlights of the tweetchat were:

      • The authors have leveraged administrative datasets to undertake numerous drug-interaction studies in the real world setting with important clinical outcomes.

      • The study reports a robust association between use of co-trimoxazole and sudden death amongst elderly patients already using a renin-angiotensin system blocker. While this remains an association, and causation is elusive in observational studies such as these, the consensus was that this is quite likely to be a true effect given the physiological basis, and prior work from this group reporting greater hospitalization for hyperkalemia from the same combination.

      • The final takeaway message was to be careful and prescribe co-trimoxazole specifically, and indeed all antibiotics generally, only when truly necessary.

      Interested individuals can track and join in the conversation by following @NephJC or #NephJC, or visit the webpage at NephJC.com.


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    1. On 2014 Nov 04, Benjamin Schwessinger commented:

      An interesting paper about the transfer of the dicot immune receptor EFR into the monocot crop rice. The authors demonstrate full functionality of the immune receptor in rice and its ability to contribute to bacterial immunity. For readers interested in the topic I would suggest to also read up on the following pre-print EFR in rice leads to ligand dependent activation of immune responses, which was posted June 11th 2014 well before initial submission of this manuscript. We regret that the author's did not cite our pre-print in their here presented work.


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    1. On 2015 Nov 30, John P A Ioannidis commented:

      Dear Joshua,

      thank you again for your comments. I am worried that you continue to cut and paste to distort my sentences.

      1. The headline over my text was written by the Nature editors as their introduction to the paper, so perhaps you should blame them and ask them to replace it with "Here follows a horrible paper by Ioannidis". Yet, I think you would still be unfair to blame them, because their headline says "most innovative and influential", not just "most innovative". The terms "influential", "influence", "major influence" pervade my paper multiple times, but you pick one sentence with "innovative" instead, and interpret it entirely out of its context.<br>
      2. The phrases "the most important" and "very important" are not identical. Very important papers may not necessarily be THE most important. But they are very important - and influential. [As an aside, honestly, this repeated cross-examining quotation-comment style makes me feel as if I am answering the Spanish Inquisition. Am I going to be burnt at the stake now (please!) or there is one more round of torture?]
      3. We agree we need evidence, more evidence - evidence is good, on everything, including the current NIH funding system, which has practically no evidence that it better than other options, but still distributes tens of billions of dollars per year. Wisely, I am sure.<br>
      4. "your list contains...". This is not my list. This is the Scopus list. Right or wrong, I preferred not to manipulate it. Your colleagues did manipulate it and did not even share the data on how exactly they manipulated it.
      5. You continue to use the term "innovative thinker" out of its context. I scanned again carefully my paper and I can't find the word "excellent". In my mind, a student who has authored as first author a paper that got over 1000 citations (and the paper is not wrong/refuted) is already worthy to be given a shot as a principal investigator. If you disagree, what can I say, feel free not to fund him/her. And please don't worry, most of these guys are not funded anyhow currently, many of them even quit science. Hundreds of principal investigators who publish absolutely nothing or publish nothing with any substantial impact get funded again and again. Hurray!<br>

      I am afraid it is unlikely there will be more convergence in our views at this point. A million thanks once again, I have learnt a lot from your comments.

      John


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    2. On 2015 Nov 03, Joshua L Cherry commented:

      John,

      I, too, am wary of an endless discussion. In my view, my straightforward original point remains unscathed by our exchange. Your latest reply does compel me to make or repeat a few points.

      1) It is perplexing that you seemingly deny that your earlier work "claimed that NIH does a poor job of funding innovators, based on the assumption that the highly cited authors that you identified were innovators". Nicholson and Ioannidis say of these authors that

      Such innovative thinkers should not have so much trouble obtaining funding as principal investigators.

      The claim that the papers are highly innovative even appears in a headline above your text. This has nothing to do with how I might interpret "innovative"; you unambiguously asserted that these authors were highly innovative, according to your own meaning, based solely on their authorship of a very highly cited article.

      2) As already noted, the two publications are at odds with each other even if we consider "importance" rather than innovativeness. The discrepancy is reflected in your reply, where you confirm your belief that

      It is an open question whether “the most highly cited papers are the most important ones”

      and yet you write that

      My assumption was that papers with over 1000 citations (i.e. in the top 0.01% of citations) are very important

      I would add that one may rationally believe that there is a correlation between citation and importance while doubting that every primary author of every one of these papers should be funded as a principal investigator. (I add this because of your subtle replacement of "whether" with "the exact extent to which".)

      3) Again, I have not asserted, much less insisted, that anybody should not be funded. I have merely questioned whether a certain criterion is a reliable indicator that a scientist is among those most worthy of funding. Those who assert that it is bear the burden of proof.

      4) Much of your latest reply is an attack on others that has nothing to do with my comments here or with anything that I have written or done. I speak only for myself. I will note as a bystander that the letter to the editor that you criticize clearly does not say what you claim it does. Among other things, it characterizes only 11% of the papers as unrelated to human health. (I imagine that you have noticed that your list of "life sciences" papers includes some that clearly appear to belong to other disciplines.)

      5)

      Let us please collect more empirical evidence and fewer opinions.

      Indeed. Let us also acknowledge that the leap from "author of a very highly cited paper" to "innovative thinker", "excellent scientist", or "person who should certainly be a principal investigator" is based largely on opinion rather than empirical evidence, as your later statements about what we do not know would suggest.


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    3. On 2015 Oct 31, John P A Ioannidis commented:

      Dear Joshua,

      Thank you for your additional insights, I suspect this topic can be hotly debated ad infinitum. Let me please try again to convey what I think:

      You claim that my earlier paper was “based on the assumption that the highly cited authors identified were innovators.” I think that either your interpretation of my assumption is misleading and/or we understand the term “innovators” differently. My assumption was that papers with over 1000 citations (i.e. in the top 0.01% of citations) are very important and thus typically their leading authors merit support (unless the papers were wrong). Importance could include disruptive innovation narrowly defined, but also other equally major qualities that merit recognition and funding. I certainly do not believe that NIH should fund only “disruptive innovators” if the definition of “disruptive innovators” excludes influential experimental studies, randomized trials, other forms of evidence-based research, and interdisciplinary research – the types of work that were excluded by the letter-to-the-editor which was coauthored by David Lipman from your team whom I greatly admire but who threw out of the NIH-relevant agenda almost all health research that is important and almost everything that matters for health. I should also confess that I am disappointed by the stance of the authors of that letter. Their lead author had asked for my raw data and I had shared everything with him within 10 minutes of his request. Then, when I saw in his re-analysis that he had excluded two-thirds of the most extremely-cited papers with the excuse that they are not within the remit of NIH (even though they are objectively categorized by Scopus as belonging to life and health sciences), I asked him to share his raw data to understand his subjective arbitrations. I was very curious to see how leading NIH officials determined that the majority of the most influential medical and health-relevant research is not within the remit of NIH. Almost three years later, I still have not had the pleasure to see their raw data. Perhaps they did not want to reveal that their re-analysis was embarrassing: the re-analysis was based on the untenable assumption that the National Institutes of Health have almost nothing to do with health and with the majority of the most influential health-related research!

      I think our inability to converge in our views lies in our difficulty to agree on what is “innovative” and “important”. For example, I argue that randomized trials and other experimental studies, meta-analyses, guidelines, implementation research, team science, and interdisciplinary science can be extremely innovative and important to fund by NIH, while probably much/most of the funded R01 type of bench work and so-called “mechanistic” research currently funded by NIH is neither "innovative" nor "important", no matter how you want to define these terms within the confines of common sense.

      The exact extent to which “the most highly cited papers are the most important ones” is indeed an open question and the 2014 Nature paper tried to contribute towards answering this question. I hope that other scientists will revisit this question and improve on what we did. I do not expect a perfect correlation between citations and importance, but this does not mean that we know nothing about citations or that they have no value. When selecting papers in the top 0.01% of citations, it is hard to claim that they would not typically be even in the top 10-15% of importance so as to be worth funding. As I said already in my previous response, the papers assessed in the 2014 Nature analysis were less cited than the ones analyzed in the 2012 Nature analysis. The median number of citations in the papers analyzed in the 2014 Nature paper was 180. Only 39 of these papers (3%) had over 1000 citations, i.e. in the same range as the extremely cited papers evaluated in the 2012 Nature analysis. All of these 39 papers actually scored well in at least one of the 5 dimensions of importance assessed (excluding publication difficulty), with an average maximum score of 83/100. This means that practically all of these papers were considered to be important; thus it is fair to assume that the work would be worth funding by NIH. Nevertheless, if you still insist that NIH should not fund the people behind papers that are so extremely influential (provided they are not wrong), I am afraid I have run out of arguments and there is no way that I will ever convince you.

      I trust both you and me and the previous letter writers, we all want to support science and celebrate the best science possible. It is fine to disagree on how to achieve this noble goal. Let us please collect more empirical evidence and fewer opinions. I would cherish to have more robust evidence, even if it were to prove me wrong. Thank you for giving me an opportunity to discuss again this interesting topic.


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    4. On 2015 Oct 28, Joshua L Cherry commented:

      Thank you, John, for your response. As I see it, the apparent inconsistencies between the two publications remain unresolved.

      The earlier work claimed that NIH does a poor job of funding innovators, based on the assumption that the highly cited authors that you identified were innovators. The later work not only provides evidence suggesting otherwise, but explicitly states that the relationship between citations and innovation is unknown. Would you agree, then, that the earlier claim about funding of innovators is unfounded? I am asking about the particular case presented there, not about other arguments or claims that might or might not involve innovativeness.

      I would note, since it seems to be necessary, that the emphasis on innovativeness does not originate with me, but with your earlier publication. Your reply warns against a focus on disruptive innovativeness, but Nicholson and Ioannidis (2012) focused on innovativeness. I am merely responding to your argument. We can certainly consider whether highly cited authors necessarily have other qualities, but the shift in argument should be acknowledged.

      What, then, of the argument that your list of highly cited authors can be assumed to be among the best of the best on grounds other than innovativeness? According to your later piece there is much that we do not know about citation patterns and it is an open question whether "the most highly cited papers [are] the most important ones". How, then, can you be so certain that these authors are all exceptionally good scientists who should undoubtedly have been funded as principal investigators?

      The final paragraph of your response seems to suggest that by pointing out inconsistencies between these two publications I have laid the groundwork for an argument against funding of biomedical research. If this were correct, it is not clear how it would be relevant. (Surely you, of all people, are not suggesting self-censorship on those grounds.) But it is incorrect, and in fact backwards. I have never suggested, any more than you have, that anybody is unworthy of funding. Rather, we are discussing how to identify those most worthy of funding. Your remarks rely on the very point that we are debating: your conviction that your list of highly cited authors reliably identifies extraordinarily good scientists. Unlike my comment, your Conform and Be Funded piece, which claimed to have demonstrated empirically that NIH spends its funds unwisely, might make it difficult to argue for greater NIH funding. By pointing out that this claim was based on an unfounded assumption, I do, if anything, the opposite.

      Thank you again for engaging in this discussion.


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    5. On 2015 Oct 25, John P A Ioannidis commented:

      Dear Joshua,

      thank you for trying to make a connection between these two papers. I welcome further brainstorming and investigation on these topics. My interpretation of our results in the current paper is that highly-cited papers may be important for various reasons. Disruptive innovation is one of them, but continued progress, broader interest, and greater synthesis are more prominent features of these influential papers. This does not mean that extremely highly-cited papers are not important (even if some are more important than others), or that I would feel happy if the largest biomedical funding agency in the world does not have sufficient funds to support even the leading authors of extremely highly-cited papers. Also of note, the articles evaluated in the 2012 Nature analysis were far more cited, on average, than the papers evaluated in the 2014 Nature analysis and the sampling was very different, so the connection between the two analyses is even more tenuous.

      I continue to think that if someone has been a leader in a paper that has reached the top 0.01% of citation impact in the scientific literature (as in the articles in the 2012 analysis), that person warrants to have his/her research funded, unless this research has been clearly proven wrong and a dead end in the meanwhile. I never argued that the authors of the top-0.01% of cited papers should be the only researchers to be funded, that only disruptive innovative research should be supported, or that all great work is extremely highly-cited. I believe that it is important to support research that is innovative, but it is also important to support research that achieves continued progress, broader interest, and greater synthesis. Scientific excellence has many faces, and focusing only on disruptive innovation may even limit scientific progress and may lead to exaggerated expectations and exaggerated claims by researchers and funders who try to justify their existence in a societal environment that is unfortunately not very supportive of science.

      There is also a wider issue to be discussed in your criticism. I have always tried to make the strongest case for public support for science, I never tire to say that science is the best thing that has happened to human beings. In my humble opinion, the 2012 analysis should have offered strong support that the funding budget of NIH should be increased, since currently funds are so limited that NIH cannot even fund many of the people standing behind papers with the utmost extreme citation impact. I really do not see how it helps to make a case for more support for science, when one claims that even people behind the top-0.01% of cited work in the biomedical literature do not merit funding because their extremely high-impact work is unimportant or not relevant to NIH.

      Thank you again for your comments.


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    6. On 2015 Oct 16, Joshua L Cherry commented:

      This piece is quite astounding in light of earlier claims made by the first author in the pages of the same periodical. In the earlier piece, Nicholson and Ioannidis (Nicholson JM, 2012) based a harsh indictment of NIH funding decisions, along with a recommendation for a new policy, on a questionable assumption: that a scientist's authorship of a very highly cited article is a reliable indicator of excellence or innovativeness. This more recent work by Ioannidis et al. suggests that this assumption is false, or at best unsubstantiated, seemingly undermining the earlier work, while creating the impression that the authors never had any definite opinion on the matter.

      In a piece with the provocative title "Research grants: Conform and be funded", Nicholson and Ioannidis (Nicholson JM, 2012) analyzed the pattern of subsequent NIH funding of the primary authors (first, last, or sole authors) of very highly cited articles. Because the fraction funded as NIH principal investigators was lower than they believed it should be, they concluded that NIH does a poor job of funding innovative research. They also suggested that such authors, whom they regarded as having demonstrated exceptional innovativeness or excellence, be automatically funded as principal investigators. Several people, myself among them, argued that such authors are not necessarily innovative or exceptional scientists, but Nicholson and Ioannidis staunchly maintained their position (http://tinyurl.com/npojxk2; http://tinyurl.com/ozme26j).

      This more recent piece paints a very different picture. It begins by telling us how little we know about the meaning of citation patterns, posing such questions as "Are the most highly cited papers the most important ones?" If, as Ioannidis et al. have it, these were open questions, what basis could there have been for the conclusions of Nicholson and Ioannidis? Furthermore, to the extent that the evidence presented here tells us anything about what citation patterns actually mean, it tells us that very highly cited publications do not tend to be highly innovative, contrary to the assertions of Nicholson and Ioannidis. Strikingly, in the concluding section Ioannidis et al. tell us that

      It would be particularly useful to know whether successful out-of-the-box ideas are generated and defended largely by the most influential scientists or by colleagues lower on the citation rankings.

      Such knowledge would, indeed, be useful. It would, in fact, seem to be a prerequisite for the arguments of Nicholson and Ioannidis, a prerequisite that Ioannidis et al. tell us was unfulfilled.

      This piece makes no mention of the earlier arguments that it appears to undermine. This leaves one wondering whether Ioannidis maintains his earlier conclusions. If so, it is not clear how this can be reconciled with the present publication. If not, an indication of the change in position would be helpful.


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    1. On 2015 Jan 14, William Grant commented:

      Differences in 25-hydroxyvitamin D concentrations may explain some of the racial disparities in noncardia gastric cancer incidence rates

      The recent paper by Bautista and colleagues presented findings regarding risk modifying factors for noncardia gastric cancer related to racial disparities [1]. When averaged over the period 2000-2010, rates were highest for blacks, intermediate for Asians and Hispanics, and lowest for whites. However, median survival times were highest for Asians, followed by blacks, Hispanics, then whites. This letter proposes two factors to explain some of the findings.

      First, it is noted that gastric cancer incidence and/or mortality rates have been found significantly inversely correlated with solar UVB doses in ecological studies in Australia, China, Japan, Nordic countries, Spain, and the United States [2]. The most likely explanation for these findings is that UVB raises 25-hydroxyvitamin D [25(OH)D] concentrations [2]. 25(OH)D concentrations are correlated with skin pigmentation in the United States, with whites having the highest mean concentrations, Hispanics intermediate concentrations, and blacks the lowest concentrations [3]. Based on this information as well as many black-white health disparities that cannot be explained by socioeconomic status, stage or condition at time of diagnosis, and treatment, it has been proposed that black-white health disparities and cancer survival rates in the United States are related to the disparities in 25(OH)D concentrations [4,5]. Thus, disparities in 25(OH)D concentrations may explain the disparities in noncardia gastric cancer incidence rates reported in Ref. 1. They may also explain the higher rate of diabetes mellitus in blacks and Hispanics compared to whites, and hypertension in blacks compared to whites [4]. They may also help explain why blacks are diagnosed at younger ages than whites. In addition, Asians, blacks, and Hispanics had higher Heliocobacter pylori infection rates than whites, which would also contribute to risk of developing noncardia gastric cancer at a younger age.

      Second, age at time of diagnosis seems to affect survival rates. The data in Table 1 of Ref. 1 show that there are significant disparities in age at time of diagnosis, with whites having the highest fraction diagnosed after the age of 70 years and Asians and Hispanics the lowest fractions. A plot of median survival as a function of the percentage diagnosed after the age of 70 years yields a slope of -6.5 days/percent with r = 0.77, p = 0.23. While this regression is not significant at the 95% confidence level due to the large difference in survival times for Asians and Hispanics for similar fraction diagnosed over the age of 70 years, which could be due to differences in other factors such as diet, it does suggest that age is an important factor affecting survival rate.

      Thus, if blood samples from near or before the time of diagnosis are available, 25(OH)D concentrations could be measured to evaluate the role of vitamin D in noncardia incidence and survival rates. The effect of age at time of diagnosis can be studied using the existing data.

      References 1. Bautista MC, Jiang SF, Armstrong MA, Kakar S, Postlethwaite D, Li D. Significant racial disparities exist in noncardia gastric cancer outcomes among Kaiser Permanente's patient population. Dig Dis Sci. 2014 Oct 30. [Epub ahead of print] 2. Moukayed M, Grant WB. Molecular link between vitamin D and cancer prevention. Nutrients. 2013;5:3993-4023. 3. Ginde AA, Liu MC, Camargo CA Jr. Demographic differences and trends of vitamin D insufficiency in the US population, 1988-2004. Arch Intern Med. 2009;169:626-632. 4. Grant WB, Peiris AN. Possible role of serum 25-hydroxyvitamin D in Black–White health disparities in the United States. J Am Med Directors Assoc. 2010;11:617-628. 5. Grant WB, Peiris AN. Differences in vitamin D status may account for unexplained disparities in cancer survival rates between African and White Americans. Dermatoendocrinol. 2012;4:85-94.

      Disclosure I receive funding from Bio Tech Pharmacal (Fayetteville, AR) and Medi-Sun Engineering, LLC (Highland Park, IL).


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    1. On 2015 Jan 01, Prashant Sharma, MD, DM commented:

      The most interesting part of this case was realizing that co-inheritance of an alpha as-well-as a beta globin chain variant results in three abnormal hemoglobins on HPLC. One each corresponds to the variants as they combine with the corresponding normal chains (i.e. abnormal alpha with normal beta, normal alpha with abnormal beta), and a third when they combine with each other (abnormal alpha with abnormal beta).

      The other learning point was that abnormal alpha globin chains will result in not just a variant adult (A0) hemoglobin, but also a tiny peak of a variant HbA2 as they will combine with normal delta chains. This little spike is useful in hinting towards the fact that we are dealing with an alpha chain variant.

      Would be happy to share the full paper with anyone who requires it for personal reading.


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    1. On 2015 Nov 04, Carl de Boer commented:

      After publication, we found that our proposed mechanism was unclear, so we have published on figshare [1] a detailed model describing how a poly-dA:dT can be asymmetrically read by chromatin remodelers (http://dx.doi.org/10.6084/m9.figshare.1515926). Further, motivated by recent work by the Kornberg group, which showed that RSC can further decrease the nucleosome occupancy at poly-dA:dT sites [2], and unpublished results from Frank Pugh’s group [3], we checked for enrichment of chromatin modifiers surrounding poly-dA:dT tracts. RSC was specifically enriched in the 5’ offset NFR relative to the poly-dA:dT (http://dx.doi.org/10.6084/m9.figshare.1515927) [4], consistent with RSC recognizing and becoming stalled specifically at poly-dA:dT sequences in a strand-specific manner.

      [1] de Boer, C; Hughes, TR (2015): Model for how poly-dA:dT sites act as nucleosome turnstiles. figshare. http://dx.doi.org/10.6084/m9.figshare.1515926 Retrieved 18:47, Aug 28, 2015 (GMT)

      [2] Lorch Y, Maier-Davis B, Kornberg RD. Role of DNA sequence in chromatin remodeling and the formation of nucleosome-free regions. Genes Dev. 2014 Nov 15;28(22):2492-7. doi: 10.1101/gad.250704.114.

      [3] Wal M, Krietenstein N, Watanabe S, Peterson CL, Korber P, Pugh BF. Unpublished results.

      [4] de Boer, C; Hughes, TR (2015): The RSC complex may be the poly-A nucleosome turnstile mechanism. figshare. http://dx.doi.org/10.6084/m9.figshare.1515927 Retrieved 18:47, Aug 28, 2015 (GMT)


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    1. On 2014 Dec 02, Alison Harrill commented:

      This is a much-needed review of mechanisms of acetaminophen toxicity as they relate to pediatric populations. Thank you for citing our paper in which we first identified a pharmacogenetic risk allele in CD44 in a genetically diverse mouse population and then subsequently validated the finding in two independent clinical trial cohorts. In those studies, sensitive subjects exhibited sub-acute elevations in ALT due to acetaminophen exposure at the maximum recommended therapeutic dose (which has since been lowered). Court et al. examined acetaminophen-induced acute liver failure cases and found indications that the same polymorphism in CD44 was enriched in cases of chronic acetaminophen use versus controls (PMID:24104197). To my knowledge, enrichment of this polymorphism in pediatric cases has not been evaluated.


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