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  1. Jul 2018
    1. On 2014 Oct 06, C. Robert Cloninger commented:

      Reply to Breen et al (their Part 2 of 2) On behalf of: C. Robert Cloninger, M.D., Ph.D. (Departments of Psychiatry and Genetics, Washington University School of Medicine, St. Louis, MO, USA); Igor Zwir, Ph.D. (Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA; Department of Computer Science and Artificial Intelligence, University of Granada, Spain); Gabriel A. de Erausquin, M.D., Ph.D. (Roskamp Laboratory of Brain Development, Modulation and Repair, Department of Psychiatry and Behavioral Neurosciences, University of South Florida, Tampa, FL, USA); Dragan M. Svrakic, M.D., Ph.D. (Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA); Coral del Val, Ph.D. (Department of Computer Science and Artificial Intelligence, University of Granada, Spain); Javier Arnedo, M.S. (Department of Computer Science and Artificial Intelligence, University of Granada, Spain); Rocío Romero-Zaliz, Ph.D. (Department of Computer Science and Artificial Intelligence, University of Granada, Spain); Helena Hernández-Cuervo, M.D., B.Sc. (Roskamp Laboratory of Brain Development, Modulation and Repair, Department of Psychiatry and Behavioral Neurosciences, University of South Florida, Tampa, FL, USA);

      The reply to the comments of Breen et al (their Part 2 of 2) by Cloninger on behalf of all of us responsible for analysis in the Arnedo et al article has the following five components which are posted separately as follows: (4) The Challenge of Understanding and Accepting a Change in Perspective (5) The Facts about Linkage Disequilibrium (6) The Facts about Replication and Significance Testing of SNP Selection (7) Conclusion (8) References for all sections of our postings


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    2. On 2014 Sep 28, Gerome Breen commented:

      Part 2 of 2 (see below) On behalf of: Gerome Breen, PhD (Institute of Psychiatry, King’s College London, London, UK) * Brendan Bulik-Sullivan (Broad Institute, Cambridge, MA, USA) * Mark Daly, PhD (Broad Institute, Cambridge, MA, USA) * Sarah Medland, PhD (QIMR Berghofer, Brisbane, Australia) * Benjamin Neale, PhD (Broad Institute, Cambridge, MA, USA) * Michael O’Donovan, MD PhD (Cardiff University, Cardiff, UK) * Stephan Ripke, PhD (Broad Institute, Cambridge, MA, USA) * Patrick Sullivan, MD (Karolinska Institutet, Stockholm, Sweden) * Peter Visscher, PhD (University of Queensland, Brisbane, Australia) * Naomi Wray, PhD (University of Queensland, Brisbane, Australia) *

      • Authors ordered alphabetically, all made equivalent contributions

      C. Linkage disequilibrium (LD).

      Pairs of SNPs that are physically close in the genome are often correlated due to LD. Furthermore, in samples containing individuals with different ancestry, SNPs on different chromosomes whose allele frequencies differ between populations will appear to be correlated. These are both well-known phenomenon from population genetics.

      The typical size of blocks defined by high LD is on the order of 20,000 bases, but LD is far from uniform across the genome. Using a large European sample genotyped with Affymetrix 6.0 arrays, we had previously computed the locations of particularly large blocks of LD (defined using SNPs with r2 > 0.5). The first step in the statistical methodology described by Arnedo et al. is to identify so-called “SNP sets” – sets of SNPs that travel together – which the authors believe contain some information about clinical subtypes of schizophrenia: “we first identified sets of interacting … SNPs that cluster within subgroups of individuals … regardless of clinical status” (no LD limitations were imposed). Of the 237 SNPs in Table S3 from Arnedo et al., 153 (65%) mapped to exceptionally large LD blocks larger than 100,000 bases (median 275kb, interquartile range 165-653kb, maximum 1.2 mb).

      Arnedo et al. claim repeatedly that sets of SNPs that travel together are informative about clinical subtypes of schizophrenia. A more parsimonious interpretation of the SNP clusters identified by Arnedo et al. is that these SNPs represent a combination of (1) SNPs in large LD blocks and (2) SNPs whose allele frequencies differ substantially between European and African sample subsets. Indeed, matrix factorization algorithms similar to the methods employed by Arnedo et al. have been used to identify regions with long-range LD (see Price et al., AJHG, 2008, link below).

      D. SNP selection.

      Arnedo et al. conducted genetic clustering analyses on 2,891 SNPs selected on the basis of in-sample P-values from analysis of association with case-control status and selected from a total of ~700,000 SNPs. It is therefore expected that linear or non-linear combinations of these SNPs will be associated with case-control status in the same sample (their risk statistic); this is true even if the selected SNPs are not truly associated. A permutation test is used to assess the significance of the observed phenotype/genotype clustering. In this permutation test, subjects are randomly allocated to “SNP sets” but, since the SNPs were selected because they differ in allele frequency between cases and controls, this procedure does not generate a valid null distribution. As a result, the reported P-values are incorrect.

      The strategy used by Arnedo etl al. is an example of estimation and selection of effects in a dataset and then testing (or re-estimating) them in the same data, a common pitfall of prediction analyses (Wray et al. 2013, Nature Reviews Genetics, link below). To construct a valid permutation test, the authors should have randomized case-control status in the association analysis step, selected a new set of ~3,000 SNPs and generated a distribution of their coincident test index under a truly null distribution.

      E. Replication.

      Replication of results is a well-acknowledged strategy for generating confidence in reported findings. Arnedo et al. state that they replicated their findings in two samples but, upon closer examination, it is unclear precisely what replicated, exactly how this was done, and whether the degree of “replication” deviated from that expected by chance. It was also unclear whether the replication control samples were or were not independent from the discovery sample. Such non-independence is another common pitfall in prediction or validation analysis.

      Conclusions.

      Given the remarkable claims made by Arnedo et al., it is essential that alternative explanations be excluded. Unfortunately, the authors do not provide the necessary evidence. As presented, their methodology is opaque (even to experts), meaning that their results cannot be independently validated. Arnedo et al. do not consider alternative explanations for the phenomena that they observe, such as confounding from ancestry and LD, even though these are well-known issues for the statistical methods that they employ and have been studied extensively in the statistical and population genetics literature. In addition, their multistep analysis approach is subject to multiple issues as noted above.

      We believe that it is highly likely that the results of Arnedo et al. are not relevant for schizophrenia. We urge great caution in the interpretation of the results of study.

      Links: • Arnedo et al. in PubMed, http://www.ncbi.nlm.nih.gov/pubmed/25219520 • Press release from Washington University (St Louis), https://news.wustl.edu/news/Pages/27358.aspx • Media coverage via Google News, https://news.google.com/news?ncl=dwmwseq1Mco0xVMLXz5qVDa7uJqbM&q=cloninger&lr=English&hl=en&sa=X&ei=hgIjVO-0GoGOyASxtIGAAw&ved=0CD0QqgIwCQ • Nonnegative matrix factorization and ancestry inference: http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1001117 • Pitfalls of predicting complex traits from SNPs: http://www.ncbi.nlm.nih.gov/pubmed/23774735 • Using principal components analysis to identify regions with long-range LD: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2443852


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    3. On 2014 Oct 06, C. Robert Cloninger commented:

      The Facts about Gender and the X-Chromosome

      B-S express concern about gender effects in our results. Traditional GWAS focuses on average effects in heterogeneous groups, but our novel approach focuses on uncovering genotypic-phenotypic relationships in individuals regardless of their gender. B-S were concerned about the possible bias of results from 15 SNPs on the X-chromosome among 245 SNPs in high-risk SNP sets. However, a simple test based on the number of chromosomes shows that 15 SNPs cannot substantially confound the results. It is true that three of our 42 high-risk SNP sets have some SNPs on the X Chromosome, but when this is considered in context along with the remaining 39 SNP sets, the influence of gender was insignificant by a Kolmogorov test. All SNP sets have consistent associations with distinct phenotypic sets regardless of gender. The effects of gender and location of genetic variants on the X-chromosome have a negligible influence on our findings. In fact, the small number of SNPs on the X-chromosome in SNP sets at high risk for schizophrenia shows that our person-centered method does not select SNPs that are in LD indiscriminately; the X-chromosome has many highly conserved sets of epistatic genes in LD that influence gender and brain function (7), but these are not overrepresented in our SNP sets at high risk for schizophrenia. We thank B-S for calling attention to another finding that demonstrates that our method for identifying SNP sets is highly selective for particular phenotypes.


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    4. On 2014 Oct 06, C. Robert Cloninger commented:

      The Facts about Ancestry and Population Stratification

      B-S expressed concern that our findings may be an artifact. As scientists we are committed to trying to disconfirm findings we have made, no matter how strong the existing evidence may be. Findings about association need to be resolved experimentally at the molecular level not only for our findings but also for the findings of other published GWAS, which we plan to do in the near future. We have previously considered the variables that concern B-S carefully, but did not report these observations in detail for two reasons. First, their impact was empirically negligible for our approach, as we will describe, and we prioritized space to the variables that were most significant. Second, although the phenomena that concern B-S are often a serious problem for traditional group-wise approaches to GWAS, they are not problematic for our novel approach because it directly tests the association between genotypic variability and phenotypic variability within individuals after deconstruction of the observed or hidden structure of the population. We will describe the facts about each of these phenomena and explain why these criticisms fall short of explaining our findings.

      B-S expressed concern that we did not take the necessary steps to correct for population stratification bias in the way they would have done using their traditional group-wise statistical approach. They suggest that the clusters we identified simply reflect “SNPs whose allele frequencies differ substantially between European and African sample subsets”, and go so far as to claim that the SNP sets we uncovered may not be relevant to schizophrenia at all. However, for that claim to be valid, ethnicity must have a strong influence on the risk and symptoms of schizophrenia, but that requirement is unlikely to be satisfied based on previous observations and was not found in our data. We did consider both sex and ancestry as co-variates in the pre-selection of SNPs with at least loose association with schizophrenia. This pre-selection was performed to reduce the large search space using the logistic association function included in the PLINK software suite (5). Our analysis was performed in this way to be compatible with the supplementary tables reported in (6) for African Americans (AA), European-Americans (EA), and individuals of mixed African and European ancestry (AA-EA). The most important fact about ethnic stratification is that there were multiple examples of SNP sets containing varying mixes of subjects from different subpopulations for each disease sub-type in each of our three independent samples of subjects. For example, in the Molecular Genetics of Schizophrenia (MGS) sample, the SNP set 22-11 was represented by 48% AA and 52% EA, SNP set 21-8 by 55% AA and 45% EA, SNP set 31-22 by 53% AA and 47% EA, SNP set 54-51 by 79% AA and 21% EA, and SNP set 71-55 by 52% AA and 48% EA.

      In fact, all the SNP sets that appeared to be ethnically stratified (i.e., contained mostly AA or EA subjects in MGS sample, such as 56-30 or 42-37) replicated their association with specific phenotypic indicators of different classes of schizophrenia in subjects of another ethnicity in CATIE or in the Portuguese sample. Although concerns about ethnic stratification may be valid elsewhere, ethnic stratification had little impact on our results and cannot explain the robust association of specific SNP sets with specific phenotypic sets regardless of ethnicity or sample. These observations show the great utility of detailed consideration of phenotypic variability in individual people in our approach, compared to the sensitivity to confounding by population stratification in traditional GWAS when heterogeneous phenotypes are lumped together indiscriminately as cases. The concerns of B-S about ethnic stratification point out a limitation of traditional group-wise GWAS that is averted by our novel approach. We thank them for drawing attention to another strength of our approach, one that we did not have enough space to report previously.

      We will discuss population stratification in more detail together with our reply about linkage disequilibrium (see posting 5), and discuss significance testing following our comments on replication in later sections of our reply to Part 2 of their comments (see posting 6).
      


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    5. On 2014 Oct 06, C. Robert Cloninger commented:

      Two Distinct Perspectives and Methodological Approaches to GWAS

      We expected our paper uncovering the hidden risk architecture of the schizophrenias to be controversial because it takes a fundamentally new approach to solve problems that have plagued the field of medical genetics for more than a decade without resolution (1). We went through rigorous peer review regarding the method with experts in bioinformatics and genetics (2) and then again regarding the application of our new approach to the schizophrenias (1). The critical comments of Breen and other colleagues of Sullivan (B-S) highlight the fact that we have a fundamentally new approach with a distinct perspective and properties from the traditional method they have used for several years. It is important to understand how our novel approach differs from the traditional one in order to appreciate the opportunities it provides for the advancement of science.

      First, in our novel approach, common disorders are recognized to have a complex etiology in which multiple genetic and environmental variables interact in complex ways to influence the risk of disease in an individual person. B_S are experienced in approaches to genome-wide association studies (GWAS) that allow detection of only the average (additive) effects of individual genes in groups of people. We regard the traditional group-wise approach to GWAS as overly restrictive because it is well established that genes typically function in concert with one another, resulting in substantial epistasis in schizophrenia and many other common disorders (3). Fitness, health, and behavior are properties of persons, not genes. Nevertheless, the traditional approach can be useful when its a priori assumptions are satisfied. The traditional and novel approaches to GWAS should be viewed as being complementary perspectives and procedures.

      Second, our novel approach allows for the possibility of complex relationships between multilocus genotypes and multifaceted phenotypes. In other words, different sets of genetic polymorphisms can be associated with the same phenotype (“equi-finality” or genetic heterogeneity), and the same set of genetic polymorphisms can be associated with multiple distinct phenotypes (“multifinality” or pleiotropy). They focus only on heterogeneous groups of cases, neglecting phenotypic variability among cases. It is important to note that our novel approach does not make any a priori assumption that complexity is present, but we do allow it to emerge from the data when present, as occurred clearly in our analysis of multiple independent samples of people with the schizophrenias.

      Third, we carry out person-centered analyses that specify genotypic-phenotypic relationships within each individual by using clustering methods in which subjects are one matrix dimension and the other matrix dimension is either genotypic or phenotypic information. In other words, our analyses are informative about each individual, thereby providing a basis for identifying specific causes of illness in each person as a basis for tailoring treatment in a personalized way. In contrast, the traditional GWAS considers only average effects in groups of people, making it unjustified to say anything with confidence about a specific individual. Such traditional methods have failed to produce any reliable genetic test for the diagnosis of any psychiatric disorder in an individual person. In addition, phenomena such as population stratification and linkage disequilibrium may confound interpretation of the group-wise statistics of traditional GWAS, whereas these phenomena are easily evaluated in our person-centered approach.

      Fourth, our approach is entirely data-driven using machine learning and data mining procedures that are unbiased and unsupervised (i.e., no a priori assumptions are made). Such data-driven methods have been used successfully in many fields of science but not for GWAS prior to our work. In contrast, the a priori assumptions made in the traditional GWAS approach, as used by B-S, have produced only weak associations between the average effects of individual genes and the diagnosis of schizophrenia. In fact, Sullivan and others proposed the formation of the Psychiatric Genetics Consortium (PGC) to address the problem of weak and inconsistent associations. Unfortunately, even large samples still produce only weak associations (4). In addition, even large collections of subjects have encountered what is called the “missing heritability problem” in medical genetics: most of the variability in risk for the schizophrenias has remained unexplained. For example, the resemblance of monozygotic cotwins of people with schizophrenia is much greater than can be explained by the average effects of individual genes, indicating that multiple genes act in concert to influence risk (3). Whereas the heritability of schizophrenia is estimated to be 81% from twin studies, only about 25% of the variability has been explained by traditional GWAS.

      In contrast, by applying our novel approach to GWAS we observed that sets of single nucleotide polymorphisms (SNPs) allow identification of individuals at very high risk (70% or more) and replicated the findings consistently in three independent samples. Our results can explain much more about disease risk than traditional group-wise approaches, so we are not surprised that such strong findings may come as a shock to those who have become accustomed to the weak associations identified by traditional GWAS. Again, we expected that this would be very controversial, but we’re optimistic that this fundamentally new approach will open up many new opportunities for people interested in medical genetics. Our results were so unexpected that peer-reviewers demanded replication in independent samples before acceptance. Even we were delighted with the strong replication: 81% of 42 SNP sets associated with 70 to 100% risk of schizophrenia replicated almost exactly across three independent samples, and different SNP sets were associated with distinct phenotypic syndromes in which the gene products suggest possible pathways by which the functions and expression of the genes in the brain may explain the different clinical features of individual patients.

      In summary, traditional approaches to GWAS focus on the average effects of individual genes in groups of people, whereas our novel approach focuses on the interactive effects of groups of genes in an individual person. Consequently the differences between these two approaches have profound consequences for the way they view and handle phenomena like linkage disequilibrium, population stratification, and X-linkage. Unfortunately, Breen and colleagues have not adequately appreciated the profound differences between the traditional methods of GWAS with which they are familiar and the novel approach we have developed. As a result, the criticisms they made reflect their concerns about problems that regularly occur when a traditional group-wise approach is implemented, but these concerns may have minimal pertinence to our person-centered approach and findings.


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    6. On 2014 Oct 06, C. Robert Cloninger commented:

      Reply to Breen et al (their Part 1 of 2)

      On behalf of: C. Robert Cloninger, M.D., Ph.D. (Departments of Psychiatry and Genetics, Washington University School of Medicine, St. Louis, MO, USA); Igor Zwir, Ph.D. (Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA; Department of Computer Science and Artificial Intelligence, University of Granada, Spain); Gabriel A. de Erausquin, M.D., Ph.D. (Roskamp Laboratory of Brain Development, Modulation and Repair, Department of Psychiatry and Behavioral Neurosciences, University of South Florida, Tampa, FL, USA); Dragan M. Svrakic, M.D., Ph.D. (Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA); Coral del Val, Ph.D. (Department of Computer Science and Artificial Intelligence, University of Granada, Spain); Javier Arnedo, M.S. (Department of Computer Science and Artificial Intelligence, University of Granada, Spain); Rocío Romero-Zaliz, Ph.D. (Department of Computer Science and Artificial Intelligence, University of Granada, Spain); Helena Hernández-Cuervo, M.D., B.Sc. (Roskamp Laboratory of Brain Development, Modulation and Repair, Department of Psychiatry and Behavioral Neurosciences, University of South Florida, Tampa, FL, USA);

      The reply to the comments of Breen et al (their Part 1 of 2) from all of us responsible for analysis in the Arnedo et al article has the following three components which are posted separately as comments as follows: (1) Two Distinct Perspectives and Methodological Approaches to GWAS (2) The Facts about Ancestry and Population Stratification (3) The Facts about Gender and the X-chromosome

      The references for all the parts of our reply are included in the final postings about Part 2 of their comments (see posting 8 of our reply).


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    7. On 2014 Sep 28, Gerome Breen commented:

      Part 1 of 2. On behalf of Gerome Breen, PhD (Institute of Psychiatry, King’s College London, London, UK) * Brendan Bulik-Sullivan (Broad Institute, Cambridge, MA, USA) * Mark Daly, PhD (Broad Institute, Cambridge, MA, USA) * Sarah Medland, PhD (QIMR Berghofer, Brisbane, Australia) * Benjamin Neale, PhD (Broad Institute, Cambridge, MA, USA) * Michael O’Donovan, MD PhD (Cardiff University, Cardiff, UK) * Stephan Ripke, PhD (Broad Institute, Cambridge, MA, USA) * Patrick Sullivan, MD (Karolinska Institutet, Stockholm, Sweden) * Peter Visscher, PhD (University of Queensland, Brisbane, Australia) * Naomi Wray, PhD (University of Queensland, Brisbane, Australia) *

      • Authors ordered alphabetically, all made equivalent contributions

      In this study published on September 15, Arnedo et al. asserted that schizophrenia is a heterogeneous group of disorders underpinned by different genetic networks mapping to differing sets of clinical symptoms. As a result of their analyses, Arnedo et al. have made remarkable and perhaps unprecedented claims regarding their capacity to subtype schizophrenia. This paper has received considerable media attention. One claim features in many media reports, that schizophrenia can be delineated into “8 types”. If these claims are replicable and consistent, then the work reported in this paper would constitute an important advance into our knowledge of the etiology of schizophrenia.

      Unfortunately, these extraordinary claims are not justified by the data and analyses presented. Their claims are based upon complex (and we believe flawed) analyses that are said to reveal links between clusters of clinical data points and patterns of data generated by looking at millions of genetic data points. Instead of the complexities favored by Arnedo et al., there are far simpler alternative explanations for the patterns they observed. We believe that the authors have not excluded important alternative explanations – if we are correct, then the major conclusions of this paper are invalidated.

      Analyses such as these rely on independence in many ways: among variables used in prediction, absence of artifactual relationships between genotypes and clinical variables, and between the methods of assessing significance and replication. Below we identify five specific areas of concern that are not adequately addressed in the manuscript, each of which calls into question the conclusions of this study.

      A. Ancestry/population stratification.

      Two of the three samples the authors studied (MGS and CATIE) have substantial proportions of subjects of European and African ancestry. The third sample is from southern Europe. Ancestry is an extremely well known confounder in genetic studies with a great capacity to yield false associations. Correct inference from genomic data in samples like these requires exceptional care. In the analyses they present, there is almost no mention of how this known bias was addressed or evaluation of its impact on their results. In the samples they used, their references to sets of SNPs that track together is essentially the definition of uncorrected population structure/stratification. Indeed, a central component of their statistical methodology – nonnegative matrix factorization – has been previously employed as a method for ancestry inference in the population genetics literature (Englehardt and Stephens, PLoS Genetics, 2010, link below).

      We were unsuccessful in attempts to obtain the full list of SNPs that Arnedo et al. analyzed. Instead, we evaluated the SNPs listed in Table S3 (448 SNP entries, 245 unique SNPs as SNPs could be present more than once, and 237 SNPs with valid allele frequencies in HapMap3). We computed the absolute value of the difference in allele frequencies between the CEU (northwest European) and YRI (Yorubas from Nigeria) groups for all HapMap3 SNPs passing basic quality control (688K SNPs genotyped using Affymetrix 6.0 arrays to match the MGS sample). We then contrasted the SNPs used by Arnedo et al. with all other affy6 SNPs. The Table S3 SNPs had markedly larger differences between a European and an African group. The mean for the absolute difference in allele frequency was 0.27 for the Table S3 SNPs used by Arnedo et al. versus 0.19 for all other SNPs. These highly significant differences underscore our concerns about population stratification bias.

      B. X chromosome (chrX).

      We noted that 15 of 237 of the SNPs in Table S3 were on chrX (again, Table S3 contains a fraction of the SNPs used in the modeling). Inclusion of chrX SNPs will partly reflect the sex of participants. Arnedo et al. say in their supplement that they include sex as a covariate in their regressions, but they do not describe how they account for sex in their matrix factorization. For example, since males have only one copy of chrX, genotypes for males will be either 0 or 1 whereas chrX genotypes for females will be either 0, 1 or 2. This difference will be salient to clustering algorithms such as those employed by the authors, so it seems likely that some component of the clusters of individuals identified by Arnedo et al. simply reflect genotype differences between sexes rather than clinical features of schizophrenia. It is well-known in statistical genetics that the sex chromosomes require special handling, but this issue is not addressed by Arnedo et al.


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    1. On 2015 Apr 24, Melissa Raven commented:

      Inappropriate generalisation of mortality in mental disorders

      This paper is one of an increasing number that inappropriately and dramatically generalise mortality estimates from samples of patients in secondary and very often tertiary treatment for serious chronic mental disorders (in many cases psychotic disorders) to the much broader population of people with potentially diagnosable mental disorders, which are usually much less severe and are associated with much lower mortality.

      In this case, Mehta et al. have claimed that people with common mental disorders die 15-20 years earlier than people without such disorders. However, there is evidence of such a mortality gap only for people with chronic serious mental disorders (particularly psychosis) treated in secondary/tertiary settings. They have thereby grossly inflated the premature mortality associated with (and in effect attributable to) common mental disorders.

      This statement is the problem:

      'Interventions based on robust evidence with this approach have the potential to address a public health challenge that results in a 15–20 year premature mortality gap, in which 75% of people with common mental disorders receive no treatment,24,25 and which is increasingly sidelined as wellbeing policy ahead of the evidence.' (p. 3)

      Mehta et al.'s reference 24, Ormel et al. (2008, p. 370), supports the claim that 75% of people with common mental disorders receive no treatment (in high-income countries). So far so good.

      The source of the 15-20 year premature mortality gap statistic is neither of the two references cited. It is most likely Wahlbeck et al. (2011), which reported 'men with mental disorders still live 20 years less, and women 15 years less, than the general population' (p. 453). However, the sample was of people admitted to hospital for mental disorders. Wahlbeck et al. acknowledged that the patients were not representative of all people with mental disorders: 'Less serious non-hospitalised cases of mental disorders, possibly with a better life expectancy outcome, are not included' (p. 457).

      The Wahlbeck et al. study was cited by Thornicroft and Docherty (2014) in support of their claim of a 15-20 year mortality gap, in their chapter in the UK Chief Medical Officer's Annual Report (Davies 2014) (the focus of Mehta et al.'s paper):

      'men with mental disorders on average live 20 years less, and women 15 years less, than the general population' (p. 198)

      Davies prominently and uncritically repeated Thornicroft & Docherty's claim (without citing any references) in her chapter 1, in her rationale for focusing on population mental health:

      'There is an unacceptably large 'premature mortality gap': people with mental illness die on average 15–20 years earlier than those without, often from avoidable causes.' (p. 12)

      A box below that claim unequivocally states that 'Mental illness … includes common mental disorder (including anxiety and depression), which affects nearly 1 in 4 of the population, and severe mental illness, such as psychosis, which is less common, affecting 0.5–1% of the population', leaving no doubt that the mortality claim applies to common mental disorders.

      Mehta et al.'s reference 25 (Chang et al. 2010) did not report a mortality gap. However, another paper by several of the same authors (Chang et al. 2011) reported a somewhat smaller premature mortality gap (8 to14.6 years for men, and 9.8 to 17.5 years for women). [Clearly Mehta et al. have accidentally cited the wrong paper by Chang et al., making it harder to check the validity of their claim.] Again the sample was unrepresentative and biased towards more severe and more chronic cases. Chang et al. appropriately emphasised:

      'Potential limitations include the secondary healthcare setting; this should present no problem for high penetrance disorders, such as schizophrenia and bipolar disorder, where most cases will have received secondary care input. However, findings for substance use disorders and depressive disorders should be viewed with circumspection since those appearing on a secondary care register are likely to be an unrepresentative (and probably more severe) subset of community cases. Ultimately, the findings for life expectancy should be taken as referring to people with these mental disorders who had made contact with secondary mental health services within the given time period and are not necessarily applicable to all cases in a given community.' (p. 5)

      Mehta et al. (and Thornicroft & Docherty, and Davies) have ignored these authors' cautions. Their claim that people with common mental disorders die 15-20 years earlier than people without such disorders seriously misrepresents the evidence. It is ironic that Mehta et al.'s misleading sentence begins and ends with a focus on evidence, and occurs in a paper subtitled 'evidence-based priorities'. Similarly, it is ironic that this misleading claim is repeatedly emphasised in a report subtitled 'Investing in the Evidence'.

      See also my PubMed Commons comment about Walker et al.'s (2015) systematic review and meta-analysis of mortality in mental disorders http://www.ncbi.nlm.nih.gov/pubmed/25671328, which similarly inappropriately generalises mortality from treatment samples of severe cases to the broader population of people with potentially diagnosable disorders, and my more detailed comment about it in JAMA Psychiatry (Raven 2015).

      References

      Chang CK, Hayes RD, Broadbent M, et al. (2010). All-cause mortality among people with serious mental illness (SMI), substance use disorders, and depressive disorders in southeast London: a cohort study. BMC Psychiatry, 10, 77. http://www.biomedcentral.com/1471-244X/10/77

      Chang CK, Hayes RD, Perera G, et al. (2011). Life expectancy at birth for people with serious mental illness and other major disorders from a secondary mental health care case register in London. PLoS One, 6(5), e19590. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0019590

      Davies SC. (2014). Annual Report of the Chief Medical Officer 2013: Public Mental Health Priorities: Investing in the Evidence. London: Department of Health. https://www.gov.uk/government/publications/chief-medical-officer-cmo-annual-report-public-mental-health

      Mehta N, Croudace T, & Davies SC. (2014). Public mental health: evidenced-based priorities. Lancet, 385(9976), 1472-1475. http://www.sciencedirect.com/science/article/pii/S0140673614614008

      Ormel J, Petukhova M, Chatterji S, et al. (2008). Disability and treatment of specific mental and physical disorders across the world. British Journal of Psychiatry, 192(5), 368-375. http://bjp.rcpsych.org/content/192/5/368.long

      Raven M. (2015). Inappropriate use of epidemiological data in analysis of mortality in mental disorders , JAMA Psychiatry. [comment re Walker et al. 2015) http://archpsyc.jamanetwork.com/article.aspx?articleid=2110027#tab10

      Thornicroft G, & Docherty M. (2014). Chapter 12 Mind the gaps – treatment, funding, access and service provision. In S. C. Davies, Annual Report of the Chief Medical Officer 2013: Public Mental Health Priorities: Investing in the Evidence. London: Department of Health. 2014. https://www.gov.uk/government/publications/chief-medical-officer-cmo-annual-report-public-mental-health

      Wahlbeck K, Westman J, Nordentoft M, Gissler M, Laursen TM. (2011). Outcomes of Nordic mental health systems: life expectancy of patients with mental disorders. British Journal of Psychiatry, 199(6), 453-458. http://bjp.rcpsych.org/content/199/6/453

      Walker, ER, McGee R, & Druss BJ. (2015). Mortality in Mental Disorders and Global Disease Burden Implications: A Systematic Review and Meta-analysis. JAMA Psychiatry, 72(4), 334-341. http://archpsyc.jamanetwork.com/article.aspx?articleid=2110027


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    1. On 2017 Sep 30, Misha Koksharov commented:

      When using firefly luciferases as an output signal in synthetic biology circuits in bacteria, it is really beneficial to use thermostable versions because they are dramatically brighter at 37°C (and other elevated temperatures) - as exemplified on the following slide:

      http://forumbgz.ru/user/upload/file593017.jpg

      Though, when growing bacteria at common room temperatures (or lower) this is not that important (as can be seen above). The reason for these effects is relatively low thermostability of WT firefly luciferases (P. pyralis, L. mingrelica, etc) combined with poor efficiency of bacterial chaperones in keeping luciferase properly folded at elevated temperatures.


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    1. On 2017 Jun 16, Jacob H. Hanna commented:

      The first of three papers from Smith group describing human transgene free "Reset cells", have failed to describe ability to generate teratomas from "transgene free" cells. Mouse naive pluripotent cells have the intrinsic "self organizing capacity" to enter a formative/primed state after in vivo SC injection and make teratomas within 4-8 weeks. I find this stunning and scientifically disturbing and wonder whether the human "reset" cells being induced do not qualify to be annotated as pluripotent cells at all. I hope the authors can clearly point out and directly address this critical caveat.


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    1. On 2014 Sep 15, Samir Ounzain commented:

      Very nice editorial discussing the interesting observations recently published from the Yvan Devaux laboratory (Vausort M, Wagner DR, Devaux Y. Long Noncoding RNAs in Patients With Acute Myocardial Infarction. Circ Res. 2014 Sep 12;115(7):668-77. doi:10.1161/CIRCRESAHA.115.303836. Epub 2014 Jul 17. PubMed PMID: 25035150).

      The potential for lncRNAs to serve as biomarkers in cardiovascular disease is very exciting and warrants further investigation. In this editorial Skroblin and Mayr raise a couple of very interesting points that need further investigation and discussion.

      They state ''All selected lncRNAs have been identified in noncardiac tissues. This lack of cardiac specificity questions their usefulness as predictors of cardiac dysfunction. At best, measuring lncRNA expression in full blood might reflect inflammation at the site of MI''.

      We agree strongly with this statement and would like to emphasise that cardiac specific/restricted lncRNAs likely represent the most important candidates both as biomarkers but also as highly specific therapeutic targets for future manipulation. Indeed, we recently demonstrated that through utilising very deep RNA-sequencing coupled with ab initio transcript reconstructions it is possible to identify 1000s of novel heart specific lncRNAs. Importantly we feel sequencing to a high depth, in a very specific context (we sequenced to a depth of 400x106 PE-reads per sample in isolated border zones post myocardial infarction, as compated to 50x106 PE-reads used in most comparable studies)is critical for the idenfication of highly cell/tissue and context specific lncRNAs, that ultimately we believe will represent the most attractive biomarkers and therapeutic targets.

      It is worth noting that when utilising this approach, we found that novel previously unknown lncRNAs were both a) much more cardiac specific than mRNAs and annotated lncRNAs (indeed many exhibit cell type specificity within the heart, b) were better correlated with cardiac physiological traits vs cannonical biomarker mRNAs and annotated lncRNAs, supporting the notion novel heart enriched lncRNAs could represent very attractive biomarkers, c) were highly associated with unique heart specific chromatin signatures linked to active -cis control enhancers, again has implications in therapeutic settings as enhancer reprogramming post stress underpins the fetal activation of gene program that is implicated in pathological remodelling and finally d) using a novel approach to infer lncRNA functions based on developmental chromatin state transitions, we found that novel lncRNAs were highly enriched in functional clusters linked to very specific cardiac functional processes including contractility etc.

      Many of the novel lncRNAs we identified in this study were conserved in human, and we hope future studies will leverage our data for the identificaiton of novel heart specific biomarkers that may be circulating in the blood. Most studies to date have only assesed the annotated long non-coding transcriptome in this setting, and we believe our paper demonstrates that novel cardiac enriched lncRNAs are likely much more interesting candidates for analysis.

      Ounzain S, Micheletti R, Beckmann T, Schroen B, Alexanian M, Pezzuto I, Crippa S, Nemir M, Sarre A, Johnson R, Dauvillier J, Burdet F, Ibberson M, Guigó R, Xenarios I, Heymans S, Pedrazzini T. Genome-wide profiling of the cardiac transcriptome after myocardial infarction identifies novel heart-specific long non-coding RNAs. Eur Heart J. 2014 Apr 30. [Epub ahead of print] PubMed PMID: 24786300.


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    1. On 2016 Nov 22, MICHAEL BALLARD commented:

      This is the republication of an article that was previously retracted from the Journal of Neuroscience. According to the authors' retraction notice, they: “...discovered errors in the quantification of the expression and/or phosphorylation of a subset of signaling pathways, particularly related to Figures 4 and 5D. Despite these errors, the major conclusions of the paper remain substantiated." The inaccurate figures and results have been excluded from this republication. The original, retracted version can be found on PubMed: https://www.ncbi.nlm.nih.gov/pubmed/23658180 and at the Journal of Neuroscience site: http://www.jneurosci.org/content/33/19/8423.long


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    1. On 2014 Sep 15, Amanda Capes-Davis commented:

      The authors use the KB cell line to study autophagy in oral squamous cell carcinoma (OSCC). Please be aware that KB is cross-contaminated with the HeLa cell line and is cervical adenocarcinoma, not OSCC.

      Cell lines should be tested for cross-contamination, using a consensus method such as short tandem repeat (STR) profiling. For a list of known cross-contaminated cell lines, see http://iclac.org/databases/cross-contaminations/.

      Many journals now require authentication testing before publication. KB is extensively used in specialist oral journals such as J Oral Pathol Med. A requirement for authentication testing in these journals would make oral research more reliable and reproducible.


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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 2014 Dec 30, MARK WEST commented:

      Comment on “Striatal firing rate reflects head movement velocity” by Namsoo Kim, Joseph W. Barter, Tatyana Sukharnikova and Henry H. Yin

      We read the experiments conducted by Kim et al. with enthusiasm. We feel that it is important to comment on previous studies that demonstrated a direct relationship between striatal activity and movement velocity, which Kim et al. support. Originally demonstrated in the nonhuman primate (DeLong, 1973), several studies in rodents have shown relationships between firing rates of dorsolateral striatal neurons and movement velocity. Kim et al. find that both putative dorsal striatal projection neurons and putative fast-spiking interneurons fire during head movements and exhibit a firing rate relationship with the velocity of head movement. Given our previous demonstration of firing rate correlations with head movement velocity in the subpopulation of dorsolateral striatal projection neurons selectively related to head movement (Pederson et al., 1997; Tang et al., 2007), it is interesting that firing of putative striatal interneurons also exhibits a relationship to movement velocity (although not subjected to sensorimotor examination of the entire body by Kim et al). We want to add information regarding dorsolateral striatal projection neurons, over half of which fire selectively in relation to activity of single body parts (Carelli and West, 1991; Cho and West, 1997), as revealed by sensorimotor examination of the entire body. These neurons exhibit movement properties which may have been outside the scope of the authors’ study. First, movement-related firing patterns are not limited to neurons phasically related to head movements, as they are found throughout the dorsolateral striatum containing single body part neurons. For instance, we have also demonstrated similar properties in neurons phasically related to vibrissae movement (Carelli and West, 1991), forelimb movement (Carelli et al, 1997) or tongue movement (Mittler et al., 1994; Tang et al., 2008). Second, each single body part neuron exhibits a preferred direction of movement. Third, though velocity of movement is a major predictor of firing rate change for many single body part neurons, not all these neurons are sensitive to velocity and some may be sensitive to one or a combination of several movement-related characteristics (e.g., movement length, movement position, etc). References: Carelli RM, West MO (1991) Representation of body by single neurons in the dorsolateral striatum of the awake, unrestrained rat. J Comp Neurol 309:231 249. Carelli RM, Wolske M, West MO (1997) Loss of lever press-related firing of rat striatal forelimb neurons after repeated sessions in a lever pressing task. J Neurosci 17: 1804-1814. Cho J, West MO (1997) Distributions of single neurons related to body parts in the lateral striatum of the rat. Brain Res 756:241-6. DeLong, MR (1973) Putamen: Activity of Single Units during Slow and Rapid Arm Movements, Science 179:1240-1242. Mittler T, Cho J, Peoples LL, West MO (1994) Representation of the body in the lateral striatum of the freely moving rat: Single neurons related to licking, Exp Brain Res 98:163-167. Pederson CL, Wolske M, Peoples LL, West MO (1997) Firing rate dependent effect of cocaine on single neurons of the rat lateral striatum. Brain Res 760:261-5. Tang C, Pawlak AP, Prokopenko V, West MO (2007) Changes in activity of the striatum during formation of a motor habit. Eur J Neurosci 25:1212-1227. Tang CC, Root DH, Duke DC, Zhu Y, Teixeria K, Ma S, Barker DJ, West MO (2009) Decreased firing of striatal neurons related to licking during acquisition and overtraining of a licking task. J Neurosci 29(44):13952-13961.


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    1. On 2014 Oct 15, Amanda Capes-Davis commented:

      Kudos to the authors for their integrity in retracting this article. Cell lines ACCM and ACC2 are known to be misidentified; instead of arising from salivary gland, ACCM and ACC2 are actually HeLa, from cervical adenocarcinoma.

      For a list of known misidentified cell lines, see http://iclac.org/databases/cross-contaminations/.


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    1. On 2014 Sep 30, Ryan Radecki commented:

      Post-publication commentary:

      "Alas, Poor (Literally) Detroit"

      High-quality care can mean many things. In the ideal sense, it conveys cooperation and coordination between the many facets of healthcare delivery – great physician care, the best possible translation of medical evidence to an individual patient, outstanding nursing, electronic systems that double-check and triple-check for safety, and an army of staff to support patients in all settings to ensure best possible health.

      Or, high-quality care can just be a number. A surrogate number, obliquely related to the ideals of quality care....

      http://www.emlitofnote.com/2014/09/alas-poor-literally-detroit.html


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    1. On 2014 Dec 21, Massimiliano Tognolini commented:

      Dear Colleagues, I do not want to discuss the connection between Alzheimer’s disease and EphA4 when demonstrated with biological tools (siRNA, mutant mice, peptides, antibodies…) in vitro or in vivo. However, major concerns raises when rhynchophylline was used. Its pharmacological characterization was very weak and flaws were present. More details are reported as comment of original paper: http://www.ncbi.nlm.nih.gov/pubmed/?term=epha4+ameliorates


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    1. On 2014 Sep 30, Ryan Radecki commented:

      Post-publication commentary:

      "Are a Third of Research Conclusions Wrong?"

      As I covered last year, half of what you’ve been taught in medicine is wrong – we just don’t know which half.

      And, it turns out, sometimes even the same authors taking a second look at the same data as before, can come up with new – and wildly different – conclusions.

      This is a review of 37 randomized-controlled trials published after 1966 paired with 37 “re-analyses” of the same data. These trials span the entire medical domain, from mycophenolate therapy after cardiac transplantation to homeopathy for fibrosis. Of these 37 re-analyses, 32 of them involved authors from the original research group. These re-analyses differed by changing statistical techniques, outcome definitions, or other study interpretation methods....

      http://www.emlitofnote.com/2014/09/are-third-of-research-conclusions-wrong.html


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    1. On 2017 Aug 11, Kerin Tyrrell commented:

      The genus Alistipes is characterized as an obligate anaerobe and asaccharolytic; however, this study describes the new species as microaerophilic and "asaccharolytic" although "Activities present are α-glucosidase, β-glucosidase, N-acetyl-β-glucos-aminidase, mannose and rafinnose (sp) fermentation". Can the authors please comment?


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    1. On 2017 Aug 07, Seán Turner commented:

      Both Enorma timonensis Ramasamy et al. 2016 [PMID 25197477] and Collinsella massiliensis Padmanabhan et al. 2016 [PMID 25197489] are described as Gram-positive, non-motile, non-sporulating rods isolated from the feces of a 53 year-old woman in an intensive care unit. Their genomes are >99.9% similar, identical within the limits of sequencing/assembly error. They should be considered heterotypic synonyms.

      Strain CSUR P902 is cited as the type strain of both "Corynebacterium ihumii" Padmanabhan et al. 2014 [PMID 25197488] and Collinsella massiliensis Padmanabhan et al. 2016 [PMID 25197489].


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    1. On 2017 Aug 07, Seán Turner commented:

      Both Enorma timonensis Ramasamy et al. 2016 [PMID 25197477] and Collinsella massiliensis Padmanabhan et al. 2016 [PMID 25197489] are described as Gram-positive, non-motile, non-sporulating rods isolated from the feces of a 53 year-old woman in an intensive care unit. Their genomes are >99.9% similar, identical within the limits of sequencing/assembly error. They should be considered heterotypic synonyms.


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    1. On 2015 Sep 28, Donald Forsdyke commented:

      General Principle of Juxtaposition- and Concentration-Dependent Activation of Complement

      Seeking to understand "immune system … ability to discriminate self from nonself," the authors here describe an elegant “clustering-based mechanism” for complement activation by MBL that is “akin to the mechanism governing signaling through many cellular receptors,” and distinguishes the lectin and classical pathways of complement activation (1). Their demonstration of the general principle of “juxtaposition- and concentration-dependent activation,” is in keeping with studies with the MBL, concanavalin-A, that were reported in 1977 (2).

      However, the latter studies were not mentioned (1), and a new review states that “the ‘lectin pathway’ was discovered in the early 1980s” (3). Thus, it is possible that those engaged in this fascinating field are unaware of the earlier work that began to be reported in 1970 (4). Subsequent studies in the 1970s (5-8) culminated in demonstration of “the importance of the sequence of binding events” (9). It is to be hoped that the full relationship of our earlier work to modern studies will be determined in future work.

      (1) Degn SE, et al. (2014) Complement activation by ligand-driven juxtaposition of discrete pattern recognition complexes. Proc. Natl. Acad. Sci. USA 111:13445-13450.

      (2) Forsdyke DR (1977) Role of receptor aggregation in complement-dependent inhibition of lymphocytes by high concentrations of concanavalin-A. Nature 267:358-360. Forsdyke DR, 1977

      (3) Thielens NM, Gaborlaud C, Thiel S (2015) Complement: classical and lectin pathways. In: eLS John Wiley & Sons, Chichester.

      (4) Milthorp P, Forsdyke DR (1970) Inhibition of lymphocyte activation at high ratios of concanavalin A to serum depends on complement. Nature 227:1351-1352. Milthorp P, 1970

      (5) Milthorp P, Forsdyke DR (1973) Serum factors affecting the incorporation of (3H)uridine by lymphocytes stimulated by concanavalin A. Studies of the role of complement. _Biochem. J. 132:803-812.Milthorp P, 1973

      (6) Milthorp P, Forsdyke DR (1973) A comparison of the activation of thymus and lymph-node cells by concanavalin A and phytohaemagglutinin. Effects of complement. J. Immun. Meth. 2:269-277.Milthorp P, 1973

      (7) Forsdyke DR (1978) Role of complement in the toxicity of dietary legumes. Med. Hypoth. 4:97-100 Forsdyke DR, 1978

      (8) Forsdyke DR, Milthorp P (1979) Early onset inhibition of lymphocytes in heterologous serum by high concentrations of concanavalin-A. Further studies of the role of complement with suramin and heated serum. Int. J. Immunopharmacol. 1:133-139.Forsdyke DR, 1979

      (9) Forsdyke DR (1980) Lectin pulses as determinants of lymphocyte activation and inactivation during the first six hours of culture: sequential action of concanavalin-A and complement cause cell lysis. Can. J. Biochem. 58:1387-1396. Forsdyke DR, 1980


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    1. On 2014 Nov 22, IRWIN FEINBERG commented:

      Giedd et al suggest that the changes they measured longitudinally in MRI-estimated cortical volume (and in cortical thickness in previous reports) might index synaptic proliferation and elimination. This seems implausible. As the authors of this study likely recognize, changes in dendritic spines are well-below the limits of current MRI resolution. In addition, the trajectories and magnitudes of the MRI changes deviate from those of the best available data for synaptic density (Huttenlocher 1979). Synaptic density is falling steeply while MRI cortical measures are changing only slightly across adolescence. Although Huttenlocher’s synaptic density data do not contain measurements during adolescence, they do show a 40 to 50% drop off from late childhood to early adulthood, much larger than the 10-15% decline in gray matter volume reported by Giedd et al. There are other brain measures (cortical metabolic rate and NREM delta amplitude) with cross-sectionally measured trajectories that visually and statistically more closely parallel the synaptic density data and might therefore better index this developmentally critical brain variable (Feinberg, Thode et al. 1990). The NREM delta trajectories have recently been confirmed in a longitudinal study which also identified ages 12-16.5 yrs as a period of accelerated brain maturation (Campbell and Feinberg 2009). In contrast to the sleep EEG, MRI measures do not reveal any period of accelerated change, nor would one expect this in post-natal measures of brain structure.

      While I do not believe the MRI studies index synaptic elimination, I strongly agree with Giedd et al that it is critical to establish the cellular basis of the developmental MRI changes. (Our laboratory has also emphasized this point (Campbell and Feinberg 2009)). However, it is unlikely that animal studies of the sort proposed by Giedd et al could provide conclusive answers because of species differences. For example, cortical synaptic development in monkeys is isochronic rather than heterochronic as in humans ((Rakic, Bourgeois et al. 1986)). What is urgently needed is a large scale multisite replication of Huttenlocher’s heroic, post-mortem study of human brains. New investigations could include biochemical as well as ultramicroscopic measures of dendritic components and morphology. Such data could also fill in the age gaps in Huttenlocher’s dataset, providing more detailed maturational trajectories for synaptic connectivity. In addition, when ante-mortem MRI studies are available, they could be related to the post-mortem findings, so that the anatomic basis of developmental MRI changes could be determined. Replications lack research glamor. In this instance, however, a replication (and major extension) is urgently needed to understand existing findings and to provide a firm foundation for interpreting MRI and other studies of post-natal brain development.

      Campbell, I. G. and I. Feinberg (2009). "Longitudinal trajectories of non-rapid eye movement delta and theta EEG as indicators of adolescent brain maturation." Proceedings of the National Academy of Sciences of the United States of America 106(13): 5177-5180, PMID 19307577.

      Feinberg, I., et al. (1990). "Gamma distribution model describes maturational curves for delta wave amplitude, cortical metabolic rate and synaptic density." Journal of Theoretical Biology 142(2): 149-161, PMID 2161971.

      Huttenlocher, P. R. (1979). "Synaptic density in human frontal cortex - developmental changes and effects of aging." Brain Research 163(2): 195-205, PMID 427544.

      Rakic, P., et al. (1986). "Concurrent overproduction of synapses in diverse regions of the primate cerebral cortex." Science 232(4747): 232-235, 3952506.


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    1. On 2014 Sep 13, Hilda Bastian commented:

      The authors make an important point: just because a systematic review has not assessed publication bias (PB), it does not mean that there is none.

      However, in this study, there were only 36 reviews that did not assess publication bias, and nearly half of those were in the minority subset of reviews that didn't have a comprehensive search strategy. For many, a comprehensive search strategy is a defining characteristic of a systematic review (e.g. in DARE, the Database of Reviews of Effects). Those reviews may not be able to provide an adequate overview of published studies, either.

      The authors point out that a limitation of their study is that there were many (planned) subgroup analysis - and it's on a small number of reviews. Especially as the number of adequately systematic reviews was small, the exclusion of the Cochrane Database of Systematic Reviews - a journal that publishes systematic reviews and was eligible for their study - is disappointing. The reason given for the exclusion was because the results of the (Moher D, 2007) study showed that publication bias "is regularly performed in articles published in this database." However the authors of that study concluded the assessment of publication bias was disappointing overall. For Cochrane reviews in that study, publication bias was assessed (or intended to be assessed) in only 32% of those reviews (and it was considered in another 39%).

      (Disclosure: I work on projects related to systematic reviews at the NCBI (National Center for Biotechnology Information, U.S. National Library of Medicine.)


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    1. On 2014 Sep 29, Allan Frey commented:

      I am a scientist and was an editor of a major biological journal for several years. A portion of my basic research involved the use of very low intensity microwave radiation as a tool to study the function of biological organisms. This latter resulted in numerous published journal articles, book chapters and a book.

      The authors of the Koyama et al journal article (1) present a rather peculiar exercise that they did. It appears that they wanted to gather some data and present it in a cell phone context as though it has relevance to cell phones. They lead off their abstract and also lead off their introduction talking about cell phones. Their extensive interpretations of their data are not relevant to cell phones and thus the article is misleading from a Public Health perspective.

      It appears that they used a microwave oven frequency signal generator to produce an unmodulated signal. Such a signal is suitable for a study on heating tissue, not for a study which starts off discussing cell phones. Since cell phones use modulated signals, a cell phone relevant study requires a modulated signal and also requires a relevant carrier frequency. There is an enormous amount of published biological data that shows that the biological effects are different when one uses an unmodulated oven type signal instead of a modulated signal with a relevant carrier frequency. This is well known; it was even brought out in my book that was published 20 years ago (2).

      There appear to be other major faults in their exercise that make it irrelevant to cell phone research and possibly other research. But since their energy frequency and modulation were inappropriate and this, in itself, discredits their discussing it in the context of cell phones, there is no need to discuss other faults in their exercise.

      1. Koyama S, Narita E, Suzuki Y, Taki M, Shinohara N, Miyakoshi J. Effect of a 2.45-GHz radiofrequency electromagnetic field on neutrophil chemotaxis and phagocytosis in differentiated human HL-60 cells.J Radiat Res. 2014 Sep 5. pii: rru075. PMID 25194051. [Epub ahead of print]

      2. Frey AH. Ed. On the nature of electromagnetic field interactions with biological systems. R. G. Landes Co., Austin, 1994


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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 2017 Oct 10, A. Mesut Erzurumluoglu commented:

      We seem to have found the same results (i.e. same nonsense variant in CCDC151 and same disease phenotype) round about the same time (check "Manuscript Received" dates of both papers, May/June 2014) but it seems our cilia ultrastructure photos do not match exactly. Maybe something to look into for future research...

      Our paper's (Alsaadi and Erzurumluoglu et al, 2014) URL: http://onlinelibrary.wiley.com/doi/10.1002/humu.22698/abstract


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    1. On 2015 Jun 30, thomas samaras commented:

      This an excellent report on the relation between nutrition, genes and socioeconomic factors on height. Unfortunately,a worldwide taller height has harmful ramifications and the assumption that reaching our genetic potential is beneficial has not been explored by most researchers. For example, we have the genetic potential to weigh 300 lb (136 kg) but we know this would create a lot of health and environmental problems. Therefore, we shouldn't assume that reaching our genetic potential for height is desirable.

      The 2007 WCRF report stated that as a result of industrialization and urbanization, chronic diseases have increased along with growth in height and weight. The lack of Western chronic disease before industrialization also applied to the elderly. WHO also attributed our chronic diseases to the Western diet. Many studies have found pre-Western people following traditional diets have very few Western diseases even at older ages. Many of these populations were found to be short and free of coronary heart disease and stroke.

      While demographers and epidemiologists have associated increased height with better health and longevity, many biologists, gerontologists and other researchers have found smaller body size is best for a healthy and long life. Many biological mechanisms support their conclusions.

      Research on the ramifications of increasing human height covers over 40 years. The evidence is solid that slower growth, later sexual maturation and shorter height promote health and longevity. As Levine recently reported, animal protein is not best for good health. See below.

      Note that Levine’s study finds higher protein is tied to a 4 times increase in type 2 diabetes for all ages over 50 years. Also animal protein after 65 years of age is good for us only if it doesn’t increase IGF-1 levels. The paradox is that animal protein increases IGF-1 per their own study, but other researchers have found plant protein reduces it somewhat.

      A few papers for further reading are listed next.

      Further reading

      1 Levine, Longo, Fontana, et al. Low protein intake is associated with a major reduction in IGF-1, cancer, and overall mortality in the 65 and younger but not older population. March, 2014, Cell Metabolism,19, 407-417.

      2 Samaras TT. Evidence from eight different types of studies showing that smaller body size is related to greater longevity. Journal of Scientific Research & Reports. 2014: 3 (16): 2150-2160, 2014; article no. JSRR.2014.16.003.

      3 Samaras TT (ed): Human Body Size and the Laws of Scaling: Physiological, Performance, Growth, Longevity and Ecological Ramifications. New York: Nova Science Pub; 2007.

      4 He Q, Morris BJ, Grove JS, Petrovitch H, Ross W, Masaki KH, et al. Shorter men live longer: Association of height with longevity and FOXO3 genotype in American men of Japanese ancestry. Plos ONE 9(5): e94385. doi:10.1371/journal.pone.0094385.

      5 Salaris L, Poulain M, Samaras TT. Height and survival at older ages among men born in an inland village in Sardinia (Italy), 1866-2006. Biodemography and Social Biology, 58:1, 1-13.

      6 Bartke A. Healthy Aging: Is Smaller better? A mini-review. Gerontology 2012; 58:337-43.

      7 Thomas Samaras, Commentary: Human growth, height, size: Reasons of be small. WPHNA World Public Health Nutrition Association, vol. 2, No. 3, March 2011.

       8 Samaras,Thomas T. Why Smaller Humans Are in Our Future, Policy Innovations, 10/20/2014


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    1. On 2016 Oct 11, Gillian Parker commented:

      It would be good to look at this paper alongside Julia Twigg's classification, similarly developed from qualitative research in the late 1980s (see https://www.cambridge.org/core/journals/journal-of-social-policy/article/models-of-carers-how-do-social-care-agencies-conceptualise-their-relationship-with-informal-carers/257776AD70ADD40F45683DF45086813A).

      There are echoes here of her model of how service providers view carers: as resources; as co-workers; and or as co-clients (with the person they are caring for).

      There are even stronger echoes of Lewis and Meredith's work (Daughters Who Care, 1988; London:Routledge ISBN 0-415-00682-1) where, again based on qualitative work, they classified three types of response to caring: balancing care; integrating care; and immersion in care.

      It would be good to think about how all three models/typologies stack up with each other, across different types of carers in different circumstances, and across time!


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    1. On 2014 Nov 20, Bernard Carroll commented:

      This report breaks some new ground in design – the between-site train-and test exercise and the cross-validation of case assignment to unipolar or bipolar groups. As the authors stated, the data are not sufficiently strong for clinical use. My comments are intended to improve the quality of reporting of this and similar studies.

      1. There is selective highlighting of some results and a failure to present all the important findings clearly. In particular, the performance of the classification algorithms in distinguishing patients from normal control subjects was relegated to the Supplementary Material. It can be calculated from eTable 7 that between 27.5% and 38% of controls would be misclassified in the 1-way comparison with unipolar depressed cases. The corresponding Kappa coefficients of concordance would be fair at 0.48 for the SVM method and poor at 0.28 for the GPC method. Results for the bipolar contrast with control subjects were similarly weak. If the method cannot do better than this with normal subjects then clinical use is a very long way away. These sobering data properly belong in the main body of the paper.

      2. The cross-site training - testing results for the algorithms were described as “highly significant” (page 1226). Actually, for the train (Munster) and test (Pittsburgh) exercise the Kappa values that can be calculated from Table 3 were weak at 0.28 for SVM and 0.24 for GPC methods. They were only slightly better for the Pittsburgh – Munster exercise (Kappas each 0.38).

      3. P-values were given in Table 3 and in eTables 5,6,7 – but there is no statement of what statistical analyses generated these P-values. Were they Goodness of Fit Chi-squared tests? Standard tradecraft requires that such analyses be clearly described.

      4. No correction of P-values was made for multiple comparisons. That is another aspect of standard tradecraft.

      5. No data were shown for test-retest reliability of the algorithm-derived group assignments.

      6. All the analyses were predicated on the untenable assumption that the clinical diagnoses were 100% accurate. As the DSM-5 field trials taught us, that is far from the case in the real world of clinical assessment – the Kappa value for major depressive disorder diagnoses averaged over 4 sites was poor at 0.28 (Regier et al 2013). The authors failed to consider whether this confound degraded the strength of their findings (see a discussion of this issue in Carroll BJ 1989). At the very least, a statement of diagnostic reliability for the cases in this study is needed.

      References

      Carroll BJ. Diagnostic validity and laboratory studies. Rules of the game.<br> In: The Validity of Psychiatric Diagnosis, eds., L.N. Robins and J.E. Barrett, Raven Press, New York, 1989, pp. 229-245.

      Regier DA et al. DSM-5 Field Trials in the United States and Canada, Part II: Test-Retest Reliability of Selected Categorical Diagnoses. Amer J Psychiatry 2013; 170: 59-70.


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    1. On 2014 Sep 11, Samir Ounzain commented:

      Very nice piece of work from the Visel and Pennacchio laboratories. Enhancer-templated ncRNA transcription is emerging as a common feature associated with active tissue specific enhancers. We have recently using the excellent ChIP-Seq data sets generatated by this laboratory made similiar observations specifically within the heart in various in vivo and in vitro models of cardiac differentiation and pathological remodelling. Interestingly many of these enhancers are not only templating eRNAs, as described in this study, but also PolyA+, unidirectional and multi-exonic lncRNAs. Furthermore loss of function demonstrates these enhancer templated lncRNAs are critical for the regulation of enhancer target coding genes.

      I would be fascinated to see how many of the TSTRs identified in this study are producing spliced lncRNAs and furthermore if loss-of-function leads to repressed enhancer activity on target genes.

      Great work and I look forward to future studies from this group exploring these possibilities.

      For those more interested in heart specific enhancer templated lncRNAs, please refer to our recent publications.

      Ounzain, S., Micheletti, R., Beckmann, T., Schroen, B., Alexanian, M., Pezzuto, I., Crippa, S., Nemir, M., Sarre, A., Johnson, R., et al. (2014a). Genome-wide profiling of the cardiac transcriptome after myocardial infarction identifies novel heart-specific long non-coding RNAs. European heart journal.

      Ounzain, S., Pezzuto, I., Micheletti, R., Burdet, F., Sheta, R., Nemir, M., Gonzales, C., Sarre, A., Alexanian, M., Blow, M.J., et al. (2014b). Functional importance of cardiac enhancer-associated noncoding RNAs in heart development and disease. Journal of molecular and cellular cardiology 76C, 55-70.


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    1. On 2015 May 12, University of Lausanne Genomics, Ecology and Evolution Journal Club commented:

      This paper presents very interesting example of adaptive radiation analysis. This is a summary of the discussion at our journal club. Authors aimed to understand the molecular mechanisms and genetic changes underlying phenotypic diversity in African cichlid fish. For this purpose, they sequenced the genomes of five lineages of African cichlids, including an ancestral lineage with low diversity, and analyzed six closely related species underwent recent radiation from Lake Victoria. According observed results, authors postulate that multiple evolutionary mechanisms, such as increased gene duplication, accelerated evolution of coding and regulatory elements, regulation of gene expression by novel microRNAs and transposons insertion, retention of ancient polymorphism, together with relaxed purifying selection can trigger rapid diversification in African cichlids. However, Figure 2 and some figures presented in supplementary information are unclear. It is not clear that application of three different analyses for investigation of gene duplicates was necessary due to evident constraints of methods and expected low level of overlap between results. In any case, this paper provides a great resource to extend our understanding of adaptive radiation.


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    1. On 2014 Sep 08, Raha Pazoki commented:

      Inflammation in Arrhythmia

      The role of inflammation in risk of arrhythmia is still unclear and the study by Lazzerini and colleagues Lazzerini PE, 2015 demonstrate important findings. Systemic inflammation as reflected by a rise in serum inflammatory biomarkers has been linked to arrhythmia and sudden cardiac death in the setting of other diseases such as myocardial infarction Elmas E, 2008 where the majority of fatal arrhythmia occurs. The question that is arisen by this study is that whether treatment of other types of systemic or local inflammation as is during myocardial infarction prevents arrhythmia and sudden cardiac death?


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    1. On 2014 Sep 16, Serge Ahmed commented:

      In this new Shattuck Lecture, Eric Kandel and Denise Kandel (K2) announce that they will let science speaks for itself about the role of “nicotine as a gateway drug” to other drug addictions and will not distort “what science does and does not tell us” about this controversial matter, as many others would generally do.

      However, this paper is more about cross-sensitization between nicotine and other drugs in mice than about “nicotine as a gateway drug” to other drug addictions in human populations. Basically, K2 present evidence showing that forced pre-exposure to nicotine can enhance the proportion of individual mice that become sensitive to the stimulant and rewarding effects of a low dose of cocaine. In fact, after nicotine pre-exposure, a large majority of mice become sensitized to cocaine (i.e., up to 78-98% of mice). This proportion contrasts with the small minority of cigarette smokers who go on to develop cocaine addiction in human populations (i.e., 20%). This large discrepancy complicates the extrapolation between mice and humans but is ignored by K2. Would it imply that nicotine-exposed mice are more vulnerable to cocaine addiction than cigarette smokers? Or, more likely, would it indicate that nicotine-induced sensitization to cocaine per se should not be confused with cocaine addiction?

      Research on cross-sensitization between different drugs, including nicotine and cocaine, in rats and mice were very popular among addiction researchers in the 80s and 90s. However, because drug sensitization is clearly not drug addiction, these studies have since been replaced by other, more valid animal models of drug addiction. This research is entirely ignored by K2. Thus, it remains to be demonstrated whether and to what extent initial nicotine self-administration in mice or rats can increase the proportion of individuals that develop more relevant behavioral features of cocaine addiction. Thus, we are back to the initial “scientific question of the role of nicotine as a gateway drug” to other drug addictions.

      It is perhaps the privilege of a Nobel laureate (Eric Kandel is one of the recipients of the 2000 Nobel Prize in Physiology or Medicine) to write on any subject matter by ignoring the relevant work of most other prize-free scientists. Ironically, however, a laureate is awarded this prize precisely because many other scientists have recognized the importance and relevance of his/her own previous work.

      Reading this Shattuck lecture, one is reminded of the novel “Pierre Menard, author of The Quixote” by Jorge Luis Borges. This novel illustrates how knowing the author of a text can dramatically impact our reading and interpretation of it. So I propose the following test for the interested reader. Please try to read this article as if it had not been co-authored by Eric Kandel. I bet that you will be surprised by how little this article contributes to the scientific question that it seeks to address.


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    1. On 2014 Sep 07, Jonathan Eisen commented:

      I wrote a blog post about this article for the microbiology of the Built Environment network blog. See Nice summary of the Earth Microbiome Project by Gilbert et al..

      Also I then asked the 1st author pif the paper to discuss the history behind the paper which he did in this blog post: Behind the scenes at the Earth Microbiome Project.


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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 Feb 27, Geriatric Medicine Journal Club commented:

      This interesting randomized trial of melatonin to prevent incident delirium following hip fracture was discussed at the October 2014 Geriatric Medicine Journal Club (follow #GeriMedJC on Twitter). The full transcript of the discussion can be found here: http://gerimedjc.blogspot.com/2014/11/gerimedjc-october-31-2014.html?spref=tw Highlights of the discussion include the disappointment in the negative result but that this may not be the end of the melatonin and delirium story.


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    1. On 2014 Sep 20, Ryan Radecki commented:

      Post-Publication Peer Review:

      "Patient Satisfaction: It’s Door-to-Room Times (Duh)"

      As customer satisfaction becomes rapidly enshrined as our reimbursement overlord, we are all eager to improve our satisfaction scores. And, by scores, I mean: Press Ganey.

      So, as with all studies attempting to describe patient satisfaction, we unfortunately depend on the validity of the proprietary Press Ganey measurement instrument....

      http://www.emlitofnote.com/2014/09/patient-satisfaction-its-door-to-room.html


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    1. On 2015 Nov 16, Raphael Stricker commented:

      Response to the Study of Fallon et al.

      Jyotsna S. Shah PhD, Nick S. Harris PhD

      IGeneX Reference Laboratory, Palo Alto, CA

      November 15, 2015

      The analysis of Lyme disease serologic testing by Fallon et al. [1] reported that “Specialty Lab B” had an overall Borrelia burgdorferi test specificity of 42.5%. We therefore asked Dr. Fallon to send us the key for the study samples that were tested by “Specialty Lab B”, and we reviewed the data for all positive and negative samples.

      In the study by Fallon et al., it is notable that two-tier testing endorsed by the Centers for Disease Control and Prevention (CDC) had a sensitivity of only 48.6% for patients with persistent symptoms following Lyme disease treatment, similar to the low sensitivity described in the medical literature [2]. In contrast, if both the IgM and IgG Western blot (WB) results are considered positive, 33 of 37 patients (89%) with persistent Lyme disease symptoms were positive by “Specialty Lab B” interpretation.

      “Specialty Lab B” includes bands 31 kDa (Osp A) and 34 kDa (Osp B) in its interpretation of WB results [3]. Antibodies to these proteins are present later in the disease [4] as well as in patients vaccinated with the now-defunct Osp A vaccine. In addition, “Specialty Lab B” uses two strains of B. burgdorferi (B31 and 297) to make WB strips. In strain 297, the 39 kDa antigen is well expressed [5], whereas in strain B31 expression of the 39 kDa antigen can vary between 4-50% [4, 6]. These factors may explain the higher WB sensitivity of “Specialty Lab B”.

      According to the revised interpretive criteria of “Specialty Lab B”, a WB is considered positive if two of the following six bands are reactive with patient serum: 23-25 kDa (Osp C), 31 kDa (Osp A), 34 kDa (Osp B), 39 kDa (BmpA), 41 kDa (Flagellin) and 83-93 kDa. However at position 31 kDa on the WB, a non-specific protein co-migrates with Osp A [3]. Therefore both the IgM and IgG WBs are reported as indeterminate if only bands 31 kDa and 41 kDa are present. Likewise, it is known that some viral antibodies cross-react with the 83-93 kDa B. burgorferi antigen. Therefore the IgM WB is reported as negative if only bands 41 kDa and 83-93 kDa are present, and an indeterminate IgM WB is reported if only bands 31 kDa and 83-93 kDa are present. Thus “Specialty Lab B” offers the option to retest using a recombinant Osp A antigen WB to clarify whether a positive band at 31kDa indeed represents reactivity to B. burgdorferi or not.

      “Specialty Lab B” reported a significantly higher number of “healthy” controls (23/40) as positive compared to other labs. In contrast, only one “healthy” control was positive by two-tier test criteria. Of the 23 positive “healthy” controls, three had insufficient samples for retesting and therefore were excluded from further analysis. Three control samples with bands 41 kDa and 83-93 kDa on IgM WB were considered negative. The remaining 17 samples were tested with recombinant antigen WBs. Thirteen, including two positive by CDC two-tier criteria, had B. burgdorferi-specific antibodies. Two sera with a band at 31 kDa on WB were considered negative as they did not test positive on the Osp A recombinant antigen WB. Therefore 13/37 healthy controls had B. burgdorferi specific antibodies, and only two had a false-positive WB. Thus the performance of the WB by “Specialty Lab B”, when using revised interpretation criteria and recombinant antigen WB, demonstrates a specificity of 91.7%.

      According to the study by Fallon et al. [1], the sensitivity of Lyme disease antibody testing was 48.6% in the best laboratories using CDC two-tier criteria. In an effort to improve that sensitivity, “Specialty Lab B” uses additional band criteria to raise its combined IgM and IgG WB sensitivity to 89% [3]. Considering the significant underdiagnosis of Lyme disease based on poor two-tier test sensitivity, it is important to improve this sensitivity so that clinical cases of Lyme disease will not be missed.

      Lyme serology continues to be problematic and we continue to look for ways to improve sensitivity and specificity. In particular, the specificity of the tests is problematic because people living or traveling to endemic areas can have antibodies without disease [7], and antibodies of other diseases can cross-react with B. burgdorferi antigens. Therefore analysis of clinical history and symptoms is essential for the accurate diagnosis of Lyme disease. We agree with the conclusions drawn by Fallon et al. [1] that interlaboratory variability is considerable and remains a problem in Lyme disease testing.

      References

      1.Fallon BA, Pavlicova M, Coffino SW, Brenner C. A comparison of Lyme disease serologic test results from four laboratories in patients with persistent symptoms after antibiotic treatment. Clin Infect Dis. 2014; 59:1705-10.

      2.Stricker RB, Johnson L. Lyme disease diagnosis and treatment: Lessons from the AIDS epidemic. Minerva Med 2010;101:419-25.

      3.Shah JS, Du Cruz I, Narciso W, Lo W, Harris NS. Improved sensitivity of Lyme disease Western blots prepared with a mixture of Borrelia burgdorferi strains 297 and B31. Chronic Dis Int. 2014;1:7.

      4.Ma B, Christen B, Leung D, Vigo-Pelfrey C. Serodiagnosis of Lyme borreliosis by Western immunoblot: reactivity of various significant antibodies against Borrelia burgdorferi. J Clin Microbiol.1992; 30: 370–376.

      5.Engstrom, SM, Shoop E, Johnson RC. Immunoblot interpretation criteria for serodiagnosis of early Lyme disease. J Clin Microbiol. 1995; 33: 419–427.

      6.Aguero-Rosenfeld ME, Nowakowski J, Bittker S, Cooper D, Nadelman RB, et al. Evolution of the serologic response to Borrelia burgdorferi in treated patients with culture-confirmed erythema migrans. J Clin Microbiol. 1996; 34: 1–9.

      7.Steere AC, Sikand VK, Schoen RT, Nowakowski J. Asymptomatic infection with Borrelia burgdorferi. Clin Infect Dis. 2003; 37: 528–532.

      Disclosure: RBS is a member of the International Lyme and Associated Diseases Society (ILADS) and a director of LymeDisease.org. He has no financial or other conflicts to declare. JSS and NSH are members of ILADS, and they have financial interests in IGeneX Reference Laboratory.


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    1. On 2015 Apr 24, Robert Knight commented:

      The morpholino used is designed to the start ATG and has been described previously by Cornell and Eisen (2002) and by Andermann, Ungos and Raible (2002). Titration of this morpholino was shown to lead to a loss of RB neurons and progressively trigeminal neurons, lateral line nerve and dorsal root ganglia. Crucially, this also caused a reduction or loss of neuroD expression and did not affect development of primary motor neurons, revealing a specific affect on sensory neurons. We validated our use of this morpholino by quantifying the effects on RB neuron development relative to morpholino dose and showed that despite a near total loss of RB neurons in an embryos, there was no affect on the number of neurons in the mesencephalic trigeminal nucleus (MTN) or in the nucleus of the tract of the posterior commissure (nTPC). We further showed that we could not detect ngn1 expression in either MTN or nTPC neurons, supporting the results of the morpholino knockdowns. We did not examine trigeminal ganglia neurons, therefore cannot comment on whether these were also affected by loss of ngn1 function as previously described.


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    2. On 2015 Apr 19, Sandra Rieger commented:

      Knocking down ngn1 with a morpholino does not always lead to 100% knockdown of both trigeminal and RB neurons. It largely depends on the morpholino concentration and the type of morpholino used. Therefore, the statement that ngn1 is not required for trigeminal neuron development is not convincing, especially since crucial controls for the functionality of the morpholino injections are missing.


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    1. On 2015 May 04, Dorothy V M Bishop commented:

      This is a very useful study. Thanks. Will be sharing it with colleagues.

      Here in the UK we have been concerned with similar issues. We did some surveys using focus groups for those with trisomy X and XYY, and similar topics cropped up.

      We have not written this up formally, but we used the information as background when developing materials for parents and for children to help those deciding whether and how to disclose a diagnosis. These are freely available for download here:

      http://figshare.com/articles/Booklets_for_parents_and_children_XYY_and_Trisomy_X/1203560


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    1. On 2014 Sep 20, Ryan Radecki commented:

      Post-publication commentary:

      "Appropriate Resource Utilization Can Be Taught!"

      At least, that is the implication of this paper – and even though it’s probably not the most reliable demonstration of such an effect, its observations are likely valid.

      This is a very convoluted study design aiming to comment upon whether residents trained in “conservative” practice environments differed from residents trained in “aggressive” practice environments. However, “conservative” and “aggressive” were defined by utilizing a Medicare database to calculate the “End-of-Life Visit Index”. Residents trained in a region where elderly patients received greater frequency of inpatient and outpatient care at the end-of-life were judged to have trained in an “aggressive” environment....

      http://www.emlitofnote.com/2014/09/appropriate-resource-utilization-can-be.html


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    1. On 2014 Sep 03, David Keller commented:

      Why physicians should intensify, not abandon, PSA screening

      The recommendation to stop screening for prostate cancer is incorrect and will lead to a large increase in preventable cancer deaths. This monumental error was caused by the fallacy that the results of randomized, controlled trials are superior evidence to epidemiological observation, no matter how badly the trials were designed, no matter how contaminated the trial data, and without regard to the effects of intention-to-treat analysis on diminishing the measured benefits of screening. The 16 physicians and allied healthcare professionals on the USPSTF (United States Preventative Services Task Force) all hold positions of high esteem in primary-care specialties, and are expected to volunteer an average of about 4 hours of service per week. Incredibly, no urologists were enlisted to provide their crucial perspectives on PSA screening. The "D"-level recommendation against PSA screening was based on 2 poorly-designed and badly-executed clinical trials, which both generated highly corrupted data.

      First of all, one must keep in mind the important epidemiological observation that, since the introduction of widespread PSA screening in the early 1990’s, there has been a 40% decrease in prostate cancer deaths. While even such powerful observational data cannot prove cause-and-effect, it also cannot be overturned by questionable results from flawed randomized trials. The two trials used by USPSTF do not withstand even casual scrutiny.

      Both of the large randomized PSA screening trials were done in a manner which ignores the essential biological behavior of cancer cells, which is to grow and propagate faster than healthy cells. Both trials set a fixed threshold PSA level for biopsy (such as 4.0 ng/mL). Consider two men: the first man has a PSA of 3.9 in year 1 and a PSA of 4.1 in year 2. The second man has a PSA of 0.5 in year 1 and a PSA of 3.5 in year 2. Which man should have his prostate biopsied? Any rational physician would biopsy the second man, whose PSA rose by 700%, rather than the first man, whose PSA rose only about 5%. Yet, a study with a fixed biopsy threshold trigger of 4.0 would biopsy only the first man, who clearly is much less likely to have prostate cancer. By not including the rate of increase of PSA in the biopsy decision, both trials ignored information in the PSA which has the strongest correlation with the presence of prostate cancer.

      In the U.S.-based PLCO trial, 52% of the men in the control group had off-protocol PSA screening by their private physicians, while only 86% of men in the screening group adhered to the full screening protocol. The men in the PLCO control group had an average of 2.7 PSA screening tests done off-protocol over the 6-year course of study (1). The purpose of PLCO was to compare outcomes in PSA-screened men versus non-screened men, which simply did not occur. The results of PLCO were distorted beyond recognition by mandatory intention-to-treat analysis, which assigned outcomes to each subject's original randomization group, regardless of what they did during the study. The majority of "control" subjects who actually received PSA screening by their private doctors were counted as unscreened, thus diminishing the apparent benefit of PSA screening.

      The Europe-based ERSPC study, which had lower rates of protocol violations, produced data showing a significant decrease in prostate cancer mortality due to PSA screening. An ERSPC sub-study done in the city of Goteborg had a particularly low rate of off-protocol PSA testing, and showed correspondingly higher benefits in mortality reduction. The number needed to screen (NNS) to prevent one prostate cancer death at 14 years of follow-up was 293 in Göteborg, despite the fact that 24% of the men invited to be screened never showed up but were included in the intention-to-treat analysis, thus diminishing the measured benefit of screening (2).

      Another flaw in the ERSPC study was the long interval between sequential PSA tests, which averaged about 4 years (3). Such a long interval of time between samples can allow the most aggressive, fast-growing cancers to evade detection while still confined to the prostate and curable. Men over 50 should have their PSA checked at least once a year for this reason, more often if fluctuations occur, which can be averaged to produce a better estimate of the baseline PSA, deviations from the baseline, and the rate of increase of PSA. The noisier a signal, the more data samples are required to characterize it accurately.

      Prostate cancer kills more men every year than any other cancer except lung cancer. It is a serious threat to all men over age 50 with a life expectancy of greater than 10 years. We know that it is curable when confined to the prostate. More PSA testing, not less, is called for. Improved diagnostic techniques, such as high-resolution prostate MRI imaging, and numerical filtering of PSA values, are being developed. One final randomized trial, which includes all of these improvements, must be conducted to obtain a fair assessment of PSA screening. The problem will be to find enough men willing to forgo screening to fill the control group.

      In general, a man whose PSA is 0.1 has little to fear from prostate cancer, and a man whose PSA is 100 has much to fear from prostate cancer. The problem is to clearly and accurately determine how to proceed within those 3 orders of magnitude of data. The art of medicine is to act in the best interests of the patient when the scientific facts are not perfectly understood. Clinical common sense and scientific intuition demand that we measure and carefully consider the PSA levels of men over the age of 50, pending the results of further trials. Watchful waiting is always an option, which at least provides prognostic awareness.

      The results of poorly-designed and poorly-executed controlled clinical trials give the mere illusion of high-quality data. Their results should not be relied upon as a basis for treatment decisions when they contradict powerful epidemiological data and our understanding of the biological basis of the disease.

      References

      1: Gulati R, Tsodikov A, Wever EM, Mariotto AB, Heijnsdijk EA, Katcher J, de Koning HJ, Etzioni R. The impact of PLCO control arm contamination on perceived PSA screening efficacy. Cancer Causes Control. 2012 Jun;23(6):827-35. doi: 10.1007/s10552-012-9951-8. Epub 2012 Apr 10. PubMed PMID: 22488488; PubMed Central PMCID: PMC3556907.

      2: Hugosson J, Carlsson S, Aus G, Bergdahl S, Khatami A, Lodding P, Pihl CG, Stranne J, Holmberg E, Lilja H. Mortality results from the Göteborg randomised population-based prostate-cancer screening trial. Lancet Oncol. 2010 Aug;11(8):725-32. doi: 10.1016/S1470-2045(10)70146-7. Epub 2010 Jul 2. PubMed PMID: 20598634; PubMed Central PMCID: PMC4089887.

      3: Schröder FH, Hugosson J, Roobol MJ, Tammela TL, Ciatto S, Nelen V, Kwiatkowski M, Lujan M, Lilja H, Zappa M, Denis LJ, Recker F, Berenguer A, Määttänen L, Bangma CH, Aus G, Villers A, Rebillard X, van der Kwast T, Blijenberg BG, Moss SM, de Koning HJ, Auvinen A; ERSPC Investigators. Screening and prostate-cancer mortality in a randomized European study. N Engl J Med. 2009 Mar 26;360(13):1320-8. doi: 10.1056/NEJMoa0810084. Epub 2009 Mar 18. PubMed PMID: 19297566.


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    1. On 2016 Feb 18, Kristina Hanspers commented:

      The pathway in the graphical abstract for this paper (at CellPress) is available in the "Open Access Publication" collection at WikiPathways: http://www.wikipathways.org/index.php/Pathway:WP2942. This pathway can be downloaded for use in network analysis tools such as Cytoscape and PathVisio.


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    1. On 2014 Oct 16, Gaetano Santulli commented:

      This study strongly endorses the hypothesis that counteracting neurohormonal hyperactivation represents a cornerstone for the treatment of heart failure. Remarkably, the Authors did not provide any data on the smoking status of the patients nor on catecholamine levels, which I believe would contribute compelling pathophysiological insights about the modulation of autonomic nervous system by neprilysin/angiotensin receptor inhibition. Indeed, cigarette smoking has been shown to increase catecholamine release, generating important effects on cardiovascular regulation essentially via sympathetic nervous system activation (1). Supporting this view, when examining the diabetic population (one third of the enrolled patients) no significant difference was found in the specific outcome ‘death from cardiovascular causes’. This finding could be at least in part ascribable to the autonomic neuropathy and neurovascular dysfunction described in diabetes mellitus (2). In this sense, an analysis that takes into account the duration of diabetes and therapy [i.e. insulin vs oral hypoglycemics (3)] in this population would also be interesting to the Reader.

      References 1. Grassi G, Seravalle G, Calhoun DA, et al. Mechanisms responsible for sympathetic activation by cigarette smoking in humans. Circulation 1994;90:248-53. 2. Vinik AI, Maser RE, Mitchell BD, Freeman R. Diabetic autonomic neuropathy. Diabetes care 2003;26:1553-79. 3. Sardu C, Marfella R, Santulli G. Impact of diabetes mellitus on the clinical response to cardiac resynchronization therapy in elderly people. J Cardiovasc Transl Res. 2014 Apr;7(3):362-8.

      Gaetano Santulli, MD, PhD Columbia University Medical Center, New York, NY, USA


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    1. On 2014 Sep 06, Ryan Radecki commented:

      Post-publication commentary:

      "Early P2Y12 Antagonists Just Don't Seem Useful"

      When undergoing an early invasive strategy for myocardial infarction, the guidelines and trials typically support dual platelet inhibition. Most commonly, this regimen consists of aspirin and clopidogrel. However, the P2Y12 receptor antagonists ticagrelor and prasugrel have been promoted as options due to incremental increased platelet inhibition over clopidogrel. The theoretical benefits of early dual platelet inhibition include spontaneous lysis and prevention of re-thrombosis, as well as decreased early in-stent thrombosis. Unfortunately, the ACCOAST trial demonstrated early prasugrel was associated only with increased bleeding and no associated cardiovascular endpoint benefits.

      Now we have ATLANTIC, with a similar treatment strategy, utilizing ticagrelor.

      Which is also negative.

      http://www.emlitofnote.com/2014/09/early-p2y12-antagonists-just-dont-seem.html


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    1. On 2015 Jan 05, Peter Gøtzsche commented:

      Gastrointestinal cancers in the The SOLID-TIMI 52 trial

      The SOLID-TIMI 52 trial assessed whether darapladib had any effect on major coronary events compared with placebo (1). A small table of adverse events showed that people on active drug had diarrhea twice as often as those on placebo whereas there was no difference in “any adjudicated gastrointestinal cancer.” Readers may wonder why gastrointestinal cancers were listed in such a small table, as diarrhea doesn’t usually lead to cancer. The word cancer was only mentioned in the table, with no comment in the text as to why. I think the reason for listing it in the table is that studies in rats and mice have shown that they developed jejunal adenocarcinomas – a very rare cancer - after exposure to darapladib (2). This should have been mentioned in the paper. I also believe that the investigators and the sponsor, GlaxoSmithKline, have an ethical duty to follow-up the 13,026 participants in the trial in the coming years to find out whether they develop jejunal cancers. A patient who stopped his participation in the trial because of diarrhea felt he had been used as a human guinea pig, as these animal studies had not been carried out when he was asked to enroll in the trial (3).

      Conflicts of interest: none.

      1. O'Donoghue ML, Braunwald E, White HD, et al. Effect of darapladib on major coronary events after an acute coronary syndrome: the SOLID-TIMI 52 randomized clinical trial. JAMA;312:1006-15.

      2. GlaxoSmithKline. Toxicology section from the Investigator's Brochure on darapladip (24 pages). RM2003/00513/06. Undated.

      3. Gøtzsche PC. “Human guinea pig” asks for animal studies. BMJ 2014;349:g6714.


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    1. On 2015 Apr 08, DOMINIQUE BERGMANN commented:

      An anonymous peer noted that panels 6D-E are identical. This is an error on our part and we have identified the source of the error and the raw data that corresponds to the genotypes pictured. Table 2 contains quantified data related to the information in panel 6D-E and is correct. All conclusions in the paper are based on the data in Table 2. We are working to correct this error with the journal.


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    1. On 2015 Feb 06, Pavel Baranov commented:

      This paper provides an invaluable dataset of context dependent translation initiation start (TIS) efficiency. While the optimal (Kozak) TIS context has been determined a long time ago, estimating the power of individual TIS based on the contexts was usually qualitative, at best it was based on position weight matrices where the weight of each individual nucleotide was taken into account independently of other nucleotides. By systematically randomizing the context surrounding AUG codons Noderer et al measured TIS efficiencies of all 11-mers containing AUG codons. The dataset is available in Supplementary Table 2.


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    1. On 2014 Oct 03, Friedrich Thinnes commented:

      To finalize three-dimensional VDAC structure: Focus on Native VDAC will be indispensable

      This study, from my point of view, marks a great moment of VDAC research:

      1) It points another time to the relevance of cell membrane-standing VDAC-1 for the pathogenesis of Alzheimer´s Disease via apoptosis.

      2) It gives strong support to the cell membrane-expression, more precisely plasmalemmal lipid raft-integration of vertebrate VDAC-1. Furthermore, the data concerning the posphorylation of VDAC-1 in correlation to regulation of channel opening/closing argue in favor of its involvement in cell volume regulation and thus apoptosis. They are in line with much evidence indicating that plasmalemmal VDAC-1 forms the channel part of a volume regulated anion channel complex (VRAC/VSOAC).

      3) From here, VDAC-1 in the plasmalemma must be “fully closed” = collapsed = N-terminus accessible outside the barrel = closed for anions and cations, and there is evidence that the N-terminal part of native VDAC-1 can be reached by antibodies even in detergent solutions (Benz et al., 1992; Thinnes and Burckhardt, 2012).

      4) Applying canonical incorporation into black membranes, detergent-solubilized native phosphorylated mammalian VDAC-1 as well as recombinant channel preparations from E. coli inclusion bodies show only “open” = anion-selective = N-terminal stretch inside the barrel and “closed” = cation-selective = semi-collapsed = N-terminal stretch inside the barrel channel phenotypes (Teijido et al., 2012). “Fully closed” = collapsed = N-terminus accessible outside the barrel VDAC-1 states thus cannot be studied by this approach. The same holds true for more recent crystallization-based approaches. However, upcoming laser-based approaches may work just on native VDAC-1 in solutions; thus improvements to get detergent solubilized native VDAC preparation may pay to keep on the schedule.

      --Benz R, Maier E, Thinnes FP, Götz H, Hilschmann N (1992) Studies on human porin. VII. The channel properties of the human B-lymphocyte membrane-derived “Porin 31HL” are similar to those of mitochondrial porins, Biol. Chem. Hoppe Seyler. 373: 295–303. --Thinnes FP, Burckhardt G (2012) On a fully closed state of native human type-1 VDAC enriched in Nonidet P40. Mol Genet Metab 107: 632-633. --Teijido O, Ujwal R, Hillerdal CO, Kullman L, Rostovtseva TK, Abramson J (2012) Affixing N-terminal α-helix to the wall of the voltage-dependent anion channel does not prevent its voltage gating. J Biol Chem 287: 11437-11445.


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    1. On 2015 Aug 14, Oliver T Mytton commented:

      We note the comments for Kaiser et al. We are in the process of compiling a full response. When this is ready we will post it on the BMC Public Health website, linked directly to the article.

      Oliver Mytton Honorary Specialty Registrar, Centre for Diet and Activity Research (CEDAR), MRC Epidemiology Unit, Cambridge.


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    2. On 2015 Jul 08, Kathryn Kaiser commented:

      Having recently published a paper on the same topic [1], we read this paper (published August, 2014) by Mytton and colleagues (the authors) with great interest. We identified several important issues that vitiate confidence in the paper by the authors [2].

      Errors of calculation, stated protocol violations, and documentation:

      Our first concern pertains to differences in calculations in a study we both included, as well as the irreproducibility of the standard errors (SEs) reported in the Figure 2a forest plot of effects on body weight in [2]. First, we believe there is a calculation error in how the authors derived the effect size and variance in [2] for Whybrow, 2006 [3], which we both included. For clarity, we note the correct citation for the Whybrow paper is 2006, though it is sometimes cited as 2007 in [2]. Per [4], in order to reduce the potential for the over influence of studies where there are two experimental groups (300 grams per day and 600 grams per day in the case of Whybrow, 2006 [3]) compared to only a single control group, the control number (in this case, n=14) should be divided in half and rounded if necessary to the nearest integer for meta-analysis. We both calculated the same mean differences (ours reported as standardized mean differences), but substantially different confidence intervals. In the original report of outcomes [3], the effects on body weight for both treatment groups were not significant, whereas in Figure 2a [2], the confidence intervals are represented as showing a statistically significant effect for both treatment groups.

      After further examination of standard errors for the other studies in included by the authors, and being unable to recreate several of the values reported in the paper [2], we recomputed the meta-analytic statistics from the source papers after making corrections to these values (see list below for all corrected estimates). For the overall analysis, this resulted in a smaller effect [-0.54 (-1.05,-0.03)] than reported in [2]. In a more appropriate analysis and using corrected standard errors, we removed an outlier [5] that the authors had identified in the “Comparison with other studies” section on page 9 of [2]. This study had a drop-out rate of over 52 percent, did not conduct an intent-to-treat analysis, and included only 9 subjects in the final analysis. When removing this paper as suggested in [2] (but not done in Figure 2), the overall effect is -0.31 (-0.70, 0.07), p=0.11, with a drop in heterogeneity from 72 to 53%.

      Recalculated forest plot of included studies, excluding [5] are as follows (Mean Difference in Kg, 95% Confidence Interval, Standard Error): Smith-Warner 2000: (-0.09, -0.40 to 0.22, 0.16); Whybrow 2006 (600g group): (-0.62, -1.52 to 0.28, 0.46); Whybrow 2006 (300g group): (-0.77, -1.73 to 0.19, 0.49); Basu 2010: (-0.90, -1.88 to 0.08, 0.50); Peterson 2011: (0.40, -0.05 to 0.85, 0.23); Dow 2012: (-0.50, -1.30 to 0.30, 0.41); Christensen 2013: (-0.90, -2.17 to 0.37, 0.65).

      Concerning study inclusion based on the stated protocol, the authors were not consistent in the application of their criteria. The authors opted to include one study of individuals with newly diagnosed diabetes [6], despite their exclusion criterion of studies with “subjects with a medical illness that was liable to lead to weight loss or weight gain.”[2] Excluding only this study also results in non-significant findings [excluding [6]: -0.51 (-1.06, 0.03); excluding both the outlier [5] and [6] results in: -0.27 (-0.67, 0.13)]. In other words, correcting the apparent errors of inclusion and effect size calculations changes the conclusions as stated in the paper [2].

      Other points of note:

      Although some differences between our papers are the result of simple methodological differences, such as our limitation to longer than eight week studies versus the authors limitation to four weeks, other differences are more substantial. We note that the authors [2] did not use the term “obesity” in their list of keywords, which is an important omission in a review looking at weight outcomes. In addition, the authors included three studies that investigated changes in only a single fruit or vegetable, while we opted to include studies where the intervention was a variety of fruits and vegetables, in order to evaluate the more general public health message that is common today. This difference in inclusion simply represents a nuanced difference between our analyses, but it is important that searches are designed to adequately answer the question at hand. For instance, in applying the stated criteria given by the authors, we found three examples [7-9] of other studies of a single fruit or vegetable that were not included by the authors but appear to meet criteria, calling into question the thoroughness of the literature search.

      Lastly, in trying to reproduce the authors work, we noted that the list of included studies in Table 1 includes Singh, 1992 [10] while the final analysis does not. The reviewer comments and author replies posted on line at the BMC Public Health journal website indicate the authors followed the reviewer recommendation to remove the Singh paper from the analysis, yet it remains in the published table and appears to also be counted in the number in the PRISMA diagram, Figure 1. According to the forest plots in Figure 2, 7 studies were included for weight outcomes and 5 studies were included for energy intake outcomes. Figure 1 does not match the included studies in the search results reported.

      Conclusion:

      It is clear that the report presented by the authors has several concerning errors, is not consistent within itself, and does not support the conclusion the paper states that these interventions, “…result in either a small reduction in body weight or reduced weight gain relative to controls.”[2] We respectfully request that the authors reply to these concerns in order to correct the record.

      Kathryn A. Kaiser, Ph.D. Andrew W. Brown, Ph.D. David B. Allison, Ph.D. Office of Energetics, Nutrition and Obesity Research Center, School of Public Health, University of Alabama at Birmingham

      References

      \1.\ Kaiser KA, 2014 \2.\ Mytton OT, 2014 \3.\ Whybrow S, 2006 \4.\ http://handbook.cochrane.org/ \5.\ Weerts SE, 2011 \6.\ Christensen AS, 2013 \7.\ Lehtonen HM, 2010 \8.\ Thies F, 2012 \9.\ Vafa MR, 2011 \10.\ Singh RB, 1992


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    1. On 2015 Nov 13, Lydia Maniatis commented:

      The theory and method of this study simply doesn't hold up to scrutiny. Very serious problems include:

      Methods

      1. The authors claim to be motivated by previous findings of “large individual differences in lightness constancy with respect to changes in surface slant...” Yet they have only two observers per condition, and one of the observers did not complete all of the replications. Large individual differences are an indication that stimuli are ambiguous to observers, who consequently have to make quasi-guesses. In this type of situation there tends to be both intra- and inter-individual variability. Here, the small number of observers does not make either form of variability detectable.

      2. They describe having subjected observers to an “induction procedure (Allred & Brainard, 2009; Doerschner, Boyaci & Maloney, 2004) to familiarize them with the difference between surface reflectance...and the amount of light reflected from a surface [luminance]...” Surface reflectance is not perceived, but inferred (the perceptual correlate is lightness), and luminance has no perceptual correlate. The relative luminances of surfaces in context and their geometrical relationships conspire to produce local impressions of both lightness and apparent illumination. You cannot train observers to perceive luminance, which, again has no perceptual correlate (it does not correspond to white, gray, black; virtually any luminance can take on any of these perceptual values).

      An example can help make clear why such a “induction procedure” is theoretically and methodologically hollow. This is the video version of the Adelson checkerboard illusion, in which we see a square being moved from apparent shadow to apparent plain view, and changing apparent color. We can watch the video over and over again without thereby learning to see the square as constant in both its luminance and its reflectance.

      1. Asking subjects to rate the similarity in lightness of surfaces on a scale of 1 to 30 seems quite unrealistic.

      2. The mathematical acrobatics necessitated by the general shoddiness and ambiguity of the methods are moot.

      Theory

      The authors state that “Changing the orientation of an object's surface with respect to a directional light source affects the luminance of the reflected light [they mean "the luminance of the surface"] even when the light emitted by the illumination sources is held constant.” That's true.

      However, the next statement is incomplete and misleading: “The visual system can stabilize lightness with respect to such geometrical effects...” This statement needs to be highly qualified. The visual system can achieve such “lightness constancy” (requiring disambiguation of reflectance and illumination) only if the image conditions support it. An isolated surface (as that used by the authors), whether fronto-parallel or slanted, will not offer much or any such support. Thus, it should not be surprising that the authors found "essentially no lightness constancy with respect to changing the slant of a test surface..." and that "the dissimilarity data were well-accounted for by a one-dimensional perceptual representation..."

      While, again, this outcome was highly predictable, they authors are mystified by it. Noting that their results differ from those of Logvinenko and Maloney (2006), they confess that "We do not know the reason for this difference." But as they note, in that study the illumination differences were not only actual, they were (more importantly) APPARENT (a fact that can be ascertained on the basis of observation), because the setting was less spare and more informative. This is something that should have been considered before, not after data collection.

      But lightness facts and relevant literature are not of interest to these authors, who dispense with the matter early on, saying: “This form of lightness constancy [the slant surface form?] is not well-understood.” And on to data collection.


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    1. On 2014 Oct 06, Leonid Teytelman commented:

      Dear Authors,

      We have published an analysis in S. cerevisiae, showing expression-dependent artifactual ChIP enrichment at highly expressed loci (Teytelman L, 2013 "Highly expressed loci are vulnerable to misleading ChIP localization of multiple unrelated proteins"). As you know, our finding raises the question of whether HOT regions may also be influenced by the same artifact.

      It is great that you have considered our work and have thoughtfully responded to our analysis. Below, I would like to continue this discussion in an effort to better understand the artifact, its causes, and whether it may be contributing to the enrichment at the HOT loci.

      1. “we have demonstrated that there is no correlation between our non-specific binding controls (IgG) and our measured transcription factor occupancy;”

      Considering our results with no-tag control experiments, an IgG may fail to control for the artifact. It would be great if you could instead perform a GFP ChIP-Seq, similarly to what we have done in yeast.

      2. The regions determined in ref. 41 have very low enrichment (twofold or less) of non-specific immunoprecipation in anti-GFP antibody controls over input DNA evaluated using a non-standard sliding-window approach. Importantly, immunoprecipitation/input ratios at this level are typically not considered enriched for binding in modern peak-calling procedures. For example, the median immunoprecipitation/input ratio for our human RNA Pol II experiments is 20-fold, and only 0.033% of human RNA Pol II peaks contain an immunoprecipitation/input ratio ≤ twofold.

      The mean is low, but in both anti-GFP experiments, there are loci with 3-5x enrichment (figure 4D). Most importantly, while the anti-GFP enrichment at the hyper-ChIPable loci is low, please note that the level of enrichment is variable from protein to protein (2-5X for Sir proteins, but often >10X for Cse4).

      3. Thus, it is essential to note that the term ‘hyper-ChIPable’, coined by ref. 41, is quite misleading, as a correctly performed ChIP experiment will evaluate statistically enriched regions, with higher immunoprecipitation/input ratios. The so-called hyper-ChIPable regions in ref. 41 are not binding regions as determined under ChIP-seq best practices. Hence, when statistical peak-calling was performed in ref. 41 (using the established MACS peak-caller) to evaluate signals only at significantly enriched regions (Supplementary Table 1) only 17 (<7.5%) of the 238 claimed ‘hyper-ChIPable’ regions were called significant by all three Sir proteins. In fact, 68% of their 238 regions do not contain a binding site for any Sir protein as determined by MACS, despite even very liberal settings used (P < 10−5, no fold enrichment cut-off). Thus, the data of ref. 41 contradict its own major claim that all three Sir proteins showed enrichment at the 238 sites.

      By reporting the 238 sites with >2fold enrichment of Sir2, Sir3, and Sir4, we are in fact being extra-demanding in terms of the threshold. We are stringently requiring all three proteins to be enriched above a threshold at the locus. So a target with 5x enrichment of Sir2 and 1.8X enrichment of Sir3 would not pass this cutoff. A typical ChIP study will focus on a single factor at a time. Had we done that, we would have many more artifactual targets for each silencing protein, with many at 5x or higher enrichment. Furthermore, the level of the artifactual signal varies from protein to protein or experiment to experiment. For example, the Cse4 signal at highly-expressed loci can give 10x or higher enrichment.

      4. Furthermore, as indicated in Supplementary Table 3 of ref. 41, the Sir2, Sir3 and Sir4 ChIP-seq experiments were performed only once each, which raises the question as to whether enrichment of Sir proteins at the 238 sites is reproducible. More rigorously, even for the remaining 17 genomic loci, their status as hyper-ChIPable is questionable as each region would first have to be established as a reproducible binding site in replicate experiments for each individual Sir protein. If you consider that Sir2, Sir3 and Sir4 ChIP-seq constitutes three replicates of Sir proteins, their data show that most of their claimed sites were not reproducibly enriched.

      Most of our artifact-cause analysis focuses on genome-wide data, not on the 238 sites. The 238 Sir-enriched euchromatic loci were a launching point for the analysis, but most of the paper looks comprehensively at the link between expression and ChIP levels. Figures 3, 4, and 5 are all on genome-wide correlations between Pol II/III and ChIP.

      As for reproducibility, we see the same peaks, with often 10x enrichment, in Ste12, Cse4, two distinct GFP experiments, and each of the three Sir ChIP-Seq datasets. The same exact loci come up in the Sir3 paper from Oliver Rando’s group (Radman-Livaja M, 2011).

      5. In addition to the analytical differences outlined above, other potential sources for the marked differences between our data and the Sir-enriched regions of ref. 41 are deviations from a typical ChIP protocol. In particular, ref. 41 employed a significantly longer cross-link time (1 h as opposed to the typical 10–20 min). This might contribute to formation of large non-specific protein–DNA complexes, which can in turn increase non-specific immunoprecipitation.

      Though not discussed in the manuscript, we have in fact performed experiments to investigate if the crosslinking concentration contributed to the misleading signal. We performed ChIP with the 1 hour crosslinking at room temperature at the following formaldehyde concentrations: 0.0625%, .125%, .25%, .5% and 1%, but did not find a proportionate decrease in the hyper ChIPpable signal with the decreasing formaldehyde concentrations. Moreover, the presence of hyper-ChIPability in the Snyder datasets (Cse4, Ste12), ours (Sir2, 3, 4, GFP), and Rando (Sir3) make it clear that the problem is not in some unusual protocol steps in our hands.

      We also note that we initially performed the Sir ChIP-Seq experiments because of our interest in the Sir protein biology. Because the Sir proteins do not directly interact with the DNA, we used longer crosslinking times. This is not unique to our work.


      In summary, much more work is needed to pinpoint the cause of the artifact and to evaluate whether some or all of the signal at highly expressed genes in many other reported ChIP studies could be artifactual. Much more work is necessary to develop the best controls and corrections for the artifact. However, the artifact we report is not minor and is not a consequence of the methodological details of our manuscript.

      Also, please note the following papers, published almost in parallel with ours, on this topic:

      Park D, 2013 "Widespread Misinterpretable ChIP-seq Bias in Yeast" (Different analysis methods but the same conclusions in S. cerevisiae, analyzing an entirely different set of factors with ChIP-Seq experiments.)

      Kasinathan S, 2014 "High-resolution mapping of transcription factor binding sites on native chromatin" (Questions specificity of standard ChIP in S. cerevisiae and at HOT regions of Drosophila. This work possibly provides a solution to the artifact with a modification of the ChIP technique.)

      Also, the following discussion of our work on PubPeer may be useful.


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    1. On 2014 Oct 14, Hilda Bastian commented:

      Thanks for drawing attention to this interesting article. Dancer SJ, 2009 argued that what's done now in an outbreak is "a veritable blunderbuss approach." Dancer's own cross-over study of enhanced cleaning addressed MRSA, although the study was too small to identify a definite impact on infection (Dancer SJ, 2009).

      Environmental strategies were included in a systematic review of measures to reduce the spread of VRE (with a search for evidence up to June 2012)(De Angelis G, 2014). De Angelis found only two studies, concluding that no definite impact on infection had been identified (Hayden MK, 2006; Williams VR, 2009).

      This new retrospective study (Everett BR, 2017) seems to be the second looking at the implementation of this particular set of strategies. The first was undertaken by the team that developed the method and run the associated consultancy service (Watson PA, 2012).

      Both routinely and during outbreaks, Dancer SJ, 2009 concluded, "there is a lot of work still to do to establish cleaning as an evidence-based science." That still seems to be the case.


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    2. On 2014 Oct 10, Paul Watson commented:

      This is an excellent article showing a simple way to dramatically lower all hospital acquired infections with single cleaning algorithm from Steiros. The final infection rates are extremely low with immediate cost savings that I have not seen with any other infection control process. As a surgeon and an infection control practitioner, I am especially excited about the zero infection rate for total knee arthroplasties in this paper. This is something that we all strive for and has been achieved by few. Thanks for the article.


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    1. On 2014 Sep 30, Ryan Radecki commented:

      Post-publication commentary:

      "Emergency PCI for STEMI is Dead?"

      This somewhat befuddling study tries desperately to create a problem where there probably truly wasn’t – but as soon as the conflict-of-interest disclosures come up, it’s clear why.

      This is the 1-year outcomes from STREAM, a prospective, open-label, parallel-group trial enrolling participants with acute STEMI, but unlikely to undergo primary PCI within 1 hour of diagnosis. Participants were then randomized to either still undergo emergency PCI, or to fibrinolysis followed by urgent or emergency rescue PCI. The initial 1-month composite outcome, despite an excess of deaths secondary to intracranial hemorrhage in the fibrinolysis group, did not demonstrate any disadvantage to fibrinolysis with delayed PCI. There was actually a 2% absolute decrease in the composite outcome favoring fibrinolysis – and thus the 1-year follow-up, hoping this small advantage in morbidity would translate into a measurable mortality advantage....

      http://www.emlitofnote.com/2014/09/emergency-pci-for-stemi-is-dead.html


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    1. On 2014 Aug 27, Daniel Kripke commented:

      Despite much useful material, the report of Owens and colleagues about insufficient sleep was marred by insufficient evidence-based definition of insufficient sleep. “Sufficient sleep” was “defined as ≥8 hours,” but why? Consider that in a Japanese nation-wide sample of adolescents grade 7 through 12, ≥7-<8 hours was associated with the best General Health in a number of grade groups of boys and girls and overall ≥8-<9 hours was not significantly superior in predicting mental health [1]. Consider that in a unique lifetime study of mortality risk, girls sleeping 2 hours less than the average for age 16 had the same mortality as those sleeping the average, whereas mortality was about the same for boys sleeping 1 hour less than the average [2]. More evidence concerning optimal sleep durations for adolescents is needed. Should we recognize that much of the evidence-absent advocacy for children to sleep more has been financed by hypnotics manufacturers, and has been accompanied by a sharp increase in hypnotic prescriptions for children? 1. Kaneita Y, et al. J Clin Psychiatry 2007;68:1426-1435. 2. Duggan KA, et al. Health Psychol 2014, in press.


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    1. On 2014 Sep 23, Samir Ounzain commented:

      Very nice editorial describing this work by Patrick Hofmann and Reinier Boon can be found here;

      Hofmann P, Boon RA. Non-coding RNA enhances cardiac development. J Mol Cell Cardiol. 2014 Sep 18. pii: S0022-2828(14)00286-7. doi: 10.1016/j.yjmcc.2014.09.005. [Epub ahead of print] PubMed PMID: 25240640.


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    1. On 2017 Oct 01, Misha Koksharov commented:

      Of interest, depletion of an individual MRTF isoform (either MRTF-A or MRTF-B) almost completely suppressed induction of several contractile proteins despite the presence of the other MRTF isoform. This most likely indicates that both isoforms cooperate in expressional up-regulation of contractile proteins and that a certain threshold concentration of MRTF is required in order to stimulate the EMyT.

      During my previous postdoc I've observed similar effects of silencing MRTF-A and MRTF-B separately in U2OS cells when using bioluminescent real-time reporters ("SRF-luciferase") as an output. Before me it was also noticed by Gerber et al, 2013: Fig. 4. We have used the same siRNA SmartPools from Dharmacon: (siRNA sequences are in the links) against human MRTF-A, MRTF-B and SRF (and in some experiments - against mouse SRF).

      However, after a more close investigation with individual siRNAs from these pools, I came to a conclusion that the observed necessity of both MRTF forms was caused by off-target effects of some of the individual siRNAs (at least in my system):

      a) Three of the MRTF-A siRNAs also reduced mRNA levels of MRTF-B. Only one was true anti-MRTF-A siRNA (and this one also gave the highest reduction of MRTF-A mRNA levels) but it didn't reduce the reporter induction in U2OS cells in marked contrast to the pool.

      b) One of the anti-MRTF-B siRNAs caused some general off-target effects in addtion to MRTF-B knockdown: considerable cell death, blocked not only SRF but also some other pathways. Its effect on SRF-luc persisted even when the target site in MRTF-B was mutated to prevent the targeted silencing. Three other siRNA prevented most of the SRF reporters's induction and it was reduced further by adding the good single anti-MRTF-A siRNA.

      The overall conclusion was that at least in U2OS cells the MRTF-A is not essential in these reporter settings but shows a minor partial contribution if MRTF-B is depleted.

      I'll probably include this data in the later paper but for now I hope these notes will be helpful for people using these MRTF/SRF SmartPools. I strongly recommend to check the effects of individual siRNAs in them.

      By the way, one of the siRNAs in human/mouse SRF pools also showed noticeable off-target cellular toxicity (and it was not even the strongest in reducing SRF mRNA levels). Given that each of the 3 pools I've worked with had some kind of off-target effect, this confirms the warnings of Jackson AL, 2010 that this can happen quite often. :( Thus, it seems that in general it is highly desirable to check all the individual siRNAs in commercial pools for target/off-target effect and have at least 2-3 different siRNAs against the same gene confirming the knockdown phenotype.


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    1. On 2014 Oct 18, David W Brandes, MS, MD, FAAN commented:

      I am very happy to see more published information about this topic. I have been speaking professionally abut this topic for 10 years and it is becoming increasingly recognized as to it's importance in the management of MS patients. This article confirms the often unrecognized frequency of this issue. When MS patients say they "are tired all the time," we need to think about the details. Physical fatigue, cognitive fatigue, psychological fatigue (depression) and sleepiness may all be part of this complaint.


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    1. On 2014 Oct 31, Francisco Felix commented:

      One of the major concerns about the data in this paper is the prior probability of the results reflecting the truth. Antineoplastons have no scientific basis better than homeopathy or psychic surgery. Hence, the prior probability associated with the results of this paper should be so small that a bayesian correction of its estimates (by the way, they were not even reported!) must invalidate its results. Try again (actually, don't!).


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    1. On 2017 May 01, Doug Berger commented:

      LACK OF BLINDING IN THIS STUDY WAS A SERIOUS METHODOLOGIC FLAW. ADDITIONALLY, FACULTY SUPERIOR OF LEAD AUTHOR STEVEN HOLLON, DR.STEPHAN HECKERS, EDITOR OF JAMA PSYCHIATRY, BOTH AT VANDERBILT DEPT. OF PSYCHIATRY REQUIRES REPORTING AS CONFLICT OF INTEREST

      This study by Hollon et al. compared an antidepressant medication-only arm with a combined cognitive therapy/antidepressant arm and concluded that the cognitive therapy/antidepressant combination enhanced the recovery rates compared with antidepressant alone, and that the magnitude of this increment nearly doubled for patients with more severe depression.

      We opine that for subjects with greater severity, there could have been both antidepressant efficacy, as well as more hope and expectation as bias in the group who knew openly that they had received combined cognitive therapy/medication as a possible treatment. This can lead to an erroneous conclusion of greater efficacy for the combined group. The large subject number in this study could also easily lead to an erroneous finding on statistical testing as a small amount of bias in the subjects adds-up.

      In addition, it goes against clinical trial logic to compare the unbilnded-cognitive therapy/medication group to the unblinded medication-only group.This is because, as all the study arms were unblinded, the combined cognitive therapy/medication group has an advantage over the medication-only group. The combined group does not filter any hope or expectation bias that may be lurking in the cognitive therapy arm, while the medication-only group engenders no different hope or expectation than the medication arm in the combined group. It is thus logically invalid to compare the cognitive therapy-medication arm that can have an unfiltered cognitive therapy-positive bias from the unblinded nature of receiving cognitive therapy tasks by cognitive therapy trained therapists vs. the medication-only arm which has the same bias possibility as the medication in the combined group, but lacking any possible positive bias from the combined cognitive therapy arm. Medications are required to show efficacy when compared in a double-blind study that includes a blind-placebo control as these controls are necessary to filter bias of any hope or expectation of efficacy. Neither blind controls nor blinded placebo were used in the design of the Hollon et al. study here.

      Dr. Hollon should have also noted the conflict of interest in that the Director of his dept. Dr. Stephan Heckers was also on the Editorial Board of JAMA Psychiatry when this paper was submitted and was the Editor-in-Chief of JAMA Psychiatry when it was published.

      The paper was retracted once for multiple errors, and it should be withdrawn completely because of poor clinical trial logic in making claims from unblinded subjects and treaters, and in addition due to conflict of interest in having the Editorial Director (Stephan Heckers) of the publication (JAMA Psychiatry) also as head of the Faculty of the lead author's (Hollon) affiliation at Vanderbilt University.

      The full comment on the Hollon et al. study above can be read here;

      Double blinding requirement for validity claims in cognitive-behavioral therapy intervention trials for major depressive disorder. Analysis of Hollon S, et al., Effect of cognitive therapy with antidepressant medications vs antidepressants alone on the rate of recovery in major depressive disorder: a randomized clinical trial. By D. Berger. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4863672/


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    1. On 2014 Aug 22, Hilda Bastian commented:

      It's great to see such a thorough and rigorous body of work on this subject. This group provides a good overview of the portion downsizing issue, and the limited evidence base on interventions, at Vermeer WM, 2014.

      A key part of the intervention in this trial (Poelman MP, 2015) is the interactive web-based PortionSize@warenessTool. Its development and trialing is described at Poelman MP, 2013, with these elements: background reading, an interactive flash game with photos of popular food products in the Netherlands, a flash game where you can upsize/downsize portions on screen, self-test score, information on portions for children and more.

      It would be helpful if details about the availability of this intervention could be provided (e.g. where it can be viewed, if the code is open source, and if the license allows translation). The TIDieR checklist (Hoffmann TC, 2014) - the template for intervention description and replication - is a good framework for this. More details on the components of interventions is important for enabling better practice (Glasziou P, 2010).


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    1. On 2014 Sep 23, Jorge Zorzopulos commented:

      Own to the importance of the Ebola outbreak dramatically described in this paper, scientists having any likely tool that could help should have a proper channel to offer it for humanitarian reasons. However, I found extremely difficult to find such proper channel. Could the authors clarify this situation. Thank you very much Dr. Jorge Zorzopulos Buenos Aires Argentina


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    1. On 2016 Jan 08, Anne Niknejad commented:

      "Two MAGL isoforms are reported in the GenBank (long isoform 1; 313 amino acids, accession code NP-001003794 and short isoform 2; 303 amino acids, accession code NP-009214) (Labar et al., 2010)."

      Error, correct references should be:

      NP_001003794 303 aa linear PRI 15-MAR-2015

      http://www.ncbi.nlm.nih.gov/nuccore/NM_001003794.2

      this sequence corresponds to the canonical UniProt sequence isoform 1 (http://www.uniprot.org/uniprot/Q99685)

      and

      NP_009214 313 aa linear PRI 15-MAR-2015

      http://www.ncbi.nlm.nih.gov/protein/6005786

      this sequence corresponds also to UniProt isoform 1 but with initial Methionine as in UniProt isoform 2, that means longer

      • METGPEDPSS

      (303 aa + 10 aa = 313 aa)


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    1. On 2015 May 17, David Keller commented:

      Was the effect of CHF on type 2 DM adjusted for the use of thiazide diuretics, which promote insulin resistance?

      Thiazide diuretics are used widely by congestive heart failure (CHF) patients, either alone or in combination with loop diuretics (for synergy). Thiazides are well known to decrease insulin sensitivity and lead to impaired fasting glucose and frank type 2 diabetes. Was this medication side-effect adjusted for in the calculations showing that CHF increases the risk for type 2 diabetes ??


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    1. On 2014 Aug 27, Ryan Radecki commented:

      Post-publication commentary:

      Hypoxia & Overtreatment in Bronchiolitis

      “Treat the patient, not the number” works for many things in medicine – asymptomatic hypertension, hyperglycemia, and anemia, among others. However, hypoxia is less frequently dismissed as clinically irrelevant.

      And, that perfectly explains the results in this study, which evaluated clinician dependence on oxygen saturation to guide disposition in pediatric bronchiolitis....

      http://www.emlitofnote.com/2014/08/hypoxia-overtreatment-in-bronchiolitis.html


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    1. On 2014 Aug 26, Jorge H Ramírez commented:

      "Why hasn’t the intensity of scrutiny on financial interests been extended to non-financial interests ie, the ones that are far more prevalent and more strongly associated with publication misconduct?" -- Woolley K.

      Response:

      Financial conflicts of interests & their association with less retractions is not definitive evidence of more research misconducts by persons like me (i.e., non-financial conflict of interests).

      Two open questions:

      (1) How many requests of retractions for human research sponsored by pharmaceutical companies are not even openly discussed because libel laws? Re: I don't know. http://www.senseaboutscience.org/pages/keep-libel-laws-out-of-science.html

      (2) How many requests of retractions are not even eligible for open scientific debate? Re: I only know one which was requested & retracted by myself. However, question thread remains open.(1)

      Addendum to the original PubMed commons post: I just found an article describing similar cases to the situation described (yesterday) in the second question above. URL: http://www.bmj.com/content/341/bmj.c6985


      Jorge H. Ramírez. MD, MSc, PhD. Professor of Pharmacology Universidad del Valle http://chaoticpharmacology.wordpress.com/about/ Twitter: @jorgehernnramre

      References

      1. Ramirez, Jorge H (2014): Requested (Jul 29, 2014) & Retracted by the author (Aug 23, 2014): "Conelly S, et al. Dabigatran versus Warfarin in Patients with Atrial Fibrillation. N Engl J Med 2009; 361:1139-1151"] - Question Thread Open. figshare. http://dx.doi.org/10.6084/m9.figshare.1144305 Note: raw data is available in this fileset

      My conflict of interests related to this response are described in the following URLs: http://www.bmj.com/content/348/bmj.g1888/rr/763197 http://www.bmj.com/content/347/bmj.f4386/rr/763130 http://www.bmj.com/content/347/bmj.f1880/rr/763200


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    2. On 2014 Aug 25, Karen Woolley commented:

      .

      “No competing interests to declare”…oh really?

      The intensity of scrutiny of financial competing interests (eg, pharmaceutical industry sponsorship of research) is understandable – there have been enough high-profile cases of financial interests associated with publication misconduct to warrant concern. But…high-profile does not equate to high-frequency…indeed, the evidence (yes, evidence) on publications retracted for misconduct reveals that most retractions for misconduct occur for publications WITHOUT declared industry support (Woolley KL et al., Curr Med Res Opin 2011). A quick look at Retraction Watch supports the ongoing problem with non-financial interests and publication misconduct. The editors of PLoS Medicine highlighted the dangers of non-financial competing interests years ago:

      “Like all human activity, academic research and scientific publishing are inherently subjective, imperfect, and prone to bias, corruption, and self-interest. Indeed, because professional affinities and rivalries, nepotism, scientific or technological competition, religious beliefs, and political or ideological views are often the fuels for our passions and for our careers, private competing interests are perhaps even more potent than financial ones.” The PLoS Medicine Editors (2008) Making Sense of Non-Financial Competing Interests. PLoS Med 5(9): e199. doi:10.1371/journal.pmed.0050199

      When authors disclose “no competing interests to declare” what does that mean? Who is checking that nothing means nothing? Why hasn’t the intensity of scrutiny on financial interests been extended to non-financial interests ie, the ones that are far more prevalent and more strongly associated with publication misconduct?

      Our risk-management strategy for reducing the risks of interest-driven biases is rather risky. When will we prioritise strategies to manage the most prevalent and dangerous interests – the non-financial ones?

      Professor Karen Woolley PhD Certified Medical Publication Professional (Twitter: @kwproscribe)

      Disclosures

      Non-financial: Advocate for ethical publication practices, regardless of sponsor (for-profit, not-for-profit), Director of the International Society for Medical Publication Professionals and Chair of its Asia-Pacific Advisory Committee; active member of other not-for-profit organisations providing education on ethical publication practices. Author of peer-reviewed publications on ethical publication practices.

      Financial: Employee of ProScribe - part of the Envision Pharma Group (providing ethical publication planning and medical writing services to authors and sponsors worldwide - we do NOT ghostwrite)


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    1. On 2014 Sep 02, Hilda Bastian commented:

      An excellent overview of the need for studying humor in science communication, and the academic challenges in it. While there’s some more evidence than that gathered here, I think Hauke Riesch’s conclusions about the uncertainties of benefit and harm are spot on.

      I found the review on studies of humor in teaching he points to (Banas, 2011) helpful as well. From children through to continuing education and the communication of science among peers (Rockwood K, 2004), there’s a lot to learn here.

      In describing the varying results of studies, Riesch doesn’t explicitly address a key confounder in communication research: the quality of the intervention. It’s hard to make sense of bodies of evidence in this field without quality assessments and being able to see the interventions (Glasziou P, 2010). Skill in using humor may account for some of the heterogeneity. And learning about the skills necessary for effectiveness – and how to acquire them – are key issues in this field, too.

      Riesch addresses well the potentially alienating and stereotyping effect of science humor, as well as the potential benefits of social group cohesion. In addition, though, satire in peer-to-peer communication and for policy-related issues is also a critical element of humor in science communication, as it is in other areas of community life (Zyglis, 2003).

      I welcome the author’s desire to “open a discussion” on humor in science communication. But this article being behind a paywall isn’t going to help that process. It would be great to know if the author is engaging with discussion in any other forum.

      I’ve blogged about the science of humor, and humor in science, in response to this article at Scientific American.


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    1. On 2016 Nov 25, Darya Vanichkina commented:

      I was trying to reproduce the results of this study, but was unable to do so.

      The information for overall survival, TCGA subtype and treatment status is not available in the Supplementary tables, or as part of the Chinese Glioma Genome Atlas.

      Would it be possible for the authors to provide this information, perhaps in GEO or via the Chinese Glioma Genome Atlas web portal?


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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 2014 Sep 04, Kenneth Witwer commented:

      This review covers an important area of research, as saliva is obtained non-invasively and extracellular vesicles including exosomes may be enriched in useful biomarkers. Unfortunately, several apparent errors are repeated throughout the review.

      -The type of extracellular vesicle known as an "exosome" is not the same entity as the nucleic acid processing complex of the same name. A confusion of the two seems evident here. Readers will need to consult the sources to determine what information is and is not relevant to extracellular vesicles.

      -Intra- and intercellular vesicle trafficking are also conflated, with the Suedhof/Schekman/Rothman Nobel Prize research described as focused on exosomes. Secretory and secreted vesicles are certainly related, but they are distinct.


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

      This study looks at atypical antipsychotics and the risk for acute kidney injury in older adults. This paper was critically appraised at the September 2014 Geriatric Medicine Journal Club (follow #GeriMedJC on Twitter). A full transcript of the discussion can be found at http://gerimedjc.blogspot.com/2014/09/to-two-articles-critically-appraised.html?spref=tw Our colleagues from the Nephrology Journal Club (follow #NephJC on Twitter) also chimed in. In general, growing concern regarding the use of atypical antipsychotics.


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    1. On 2014 Sep 01, Ferenc Zsila commented:

      The authors claim that in relation to physiological conditions, cancer cells have substantially lower, acidic intracellular pH.

      Abstract: "...under acidic conditions (pH 5.0) mimicking the intracellular pH-conditions."

      In page 364: "Specifically, the intracellular pH of tumor cells (pH 5.0-6.5) is usually much lower than physiological pH conditions (pH 7.4), which has encour-aged researchers to develop pH-responsive prodrug formulations to improve therapeutic efficacy."

      In contrast to this statement, numerous data show that just the opposite is true: the intracellular pH of cancer cells is modestly alkaline (pH~7.4). Not the intra- but the extracellular milieu of tumours is acidic. Intracellular acidosis leads to cell death.

      Reference: Webb BA, 2011


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    1. On 2014 Sep 01, Amanda Capes-Davis commented:

      The authors describe KB as an epidermoid cell line. Although this term is widely used, it is not accurate for this cell line. KB is known to be cross-contaminated with HeLa and thus is a cervical adenocarcinoma cell line. It is not an oral squamous cell carcinoma (epidermoid carcinoma) as was originally thought.

      KB is a widely used model for multidrug resistance. To help scientists who might use KB for other applications, it would be helpful if authors can refer to KB as a HeLa derivative, and to avoid the terms epidermoid, squamous cell carcinoma, or oral.

      I note that the authors performed authentication testing. The information above would help readers to make sense of their test results. For a list of known cross-contaminated cell lines, see http://iclac.org/databases/cross-contaminations/.


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    1. On 2016 Apr 22, Kenneth Witwer commented:

      My co-authors and I found no uptake of milk miRNAs, examining the same samples reported in this paper as well as public sequencing data from these samples, Shu J, 2015. The findings encompass the two miRNAs reported by Baier et al, which are homologous in human and cow and could not be assigned to source or human by the methods of the paper, and a variety of additional miRNAs, even uniquely bovine miRNAs. It appears that both previously offered hypotheses for the observations of Baier, et al are now unsupported: the exogenous uptake hypothesis and my hypothesis, glucose-mediated regulation of endogenous RNA, Witwer KW, 2014. Instead, as also supported by rigorous experiments with genetically manipulated mouse models, Laubier J, 2015, Title AC, 2015, milk miRNAs, like other dietary RNAs Witwer KW, 2014, Dickinson B, 2013, Snow JW, 2013, do not appear to reach biologically meaningful levels in circulation, whatever this might mean, or indeed be taken up at all through the intact mammalian gut.


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    1. On 2014 Sep 15, Amanda Capes-Davis commented:

      The authors use the cell line HEp-2 to look at sensitivity to cisplatin. Please be aware that HEp-2 is cross-contaminated with HeLa, a cervical adenocarcinoma cell line. Results obtained from HEp-2 do not relate to laryngeal carcinoma.

      Cell lines can be tested for cross-contamination through consensus methods such as short tandem repeat (STR) profiling. For a list of known cross-contaminated cell lines, see http://iclac.org/databases/cross-contaminations/.


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    1. On 2014 Nov 11, Serge Ahmed commented:

      This comment is a follow-up of my previous comment about the difficulty in interpreting this study that contradicts most previous similar studies. After a careful analysis of this paper and after collecting all elements of methods “ectopically scattered” through the text, I think I finally arrived at a satisfactory explanation for why most rats preferred cocaine over sweet water in the present study. Briefly, everything was made to make access to sweet water reinforcement less direct and more difficult than access to cocaine reinforcement, thereby biasing choice towards cocaine!

      More specifically, rats had to go through an unusually long chain of behavioral events before getting access to sweet water. A similar chain was not required for cocaine delivery. First, once rats turned the wheel on the operant panel, they had to cross the cage to reach a magazine on the opposite panel inside which there was a retractable drinking spout that delivered sweet water. This arrangement introduces a spatial and thus a time gap between responding and sweet water reinforcement. Both gaps are known to reduce conditioning. Second, once rats have reached the magazine, they did not have directly access to the drinking spout that delivered sweet water. They had first to insert their head into the magazine to make the retractable drinking spout appears. This behavior amounts to a second operant response which thus defines with the first response (i.e., wheel turning) an operant chain. In addition, once rats inserted and maintained their head in the magazine, the drinking spout was not continuously available but came “back and forth in the magazine during 50s.” This is a rather unusual method of fluid delivery (note: the frequency and duration of these back-and-forth movements are not indicated in the Methods).

      Thus, to repeat, everything was made in the present paper to make access to sweet water reinforcement more difficult and less direct than access to cocaine reinforcement, thereby biasing choice towards cocaine. This unusual approach may be appropriate for addressing some scientific questions but it is misguided and inappropriate for studying the vulnerability to cocaine addiction which was the main goal of the present paper. If one wants to pursue such a goal, one better tries to make access to cocaine reinforcement equal to or more difficult than access to the nondrug option and not the other way around! Indeed, if one sufficiently weakens the nondrug option, then one will eventually reach a point where most individual rats, even the non-addicted ones, will prefer the drug! To take an extreme example, if one provides rats with ready access to cocaine but ask them to play piano or climb Mt Everest to get access to sweet water, they will surely choose cocaine over sweet water. This is not surprising, this is just trivial! In contrast, if rats take cocaine despite and at the expense of an equally or a more accessible potent nondrug option, then one has got something much less trivial and probably more relevant for studying the vulnerability to cocaine addiction.


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    2. On 2014 Aug 22, Serge Ahmed commented:

      This study is interesting and also quite embarrassing. It is interesting because of the important questions that it asks. It is embarrassing because it shows that when given a choice, most rats prefer cocaine over sweet water – a finding that is strictly the opposite of what we and others have found over the past few years. Of course, contradiction and refutation are the “game of science”. We should not be embarrassed by them and instead welcome them.

      My embarrassment comes from the fact that these opposite outcomes were obtained by a former master student of mine – Nathalie Vanhille who is the first author of this study – using a choice protocol initially developed in our lab. When Nathalie was working in our lab using this protocol, she observed that most rats preferred sweet water over cocaine – the opposite of what she now reports in this study despite the use of an identical choice protocol.

      But were the choice protocols really identical? Of course not! Like always, the devil lurks into the details and details can sometimes matter a lot! Apparently, this study differs from our previous choice studies in the way rats were given access to sweet water. In our study, access to sweet water was pretty straightforward. Rats had to press a lever to fill a nearby receptacle with sweet water. Then they could obtain additional volumes of sweet water during 20s by continually licking the receptacle. In this study, however, access to sweet water was really contrived for reasons that remain unclear until one reaches the middle of the Discussion. In fact, despite my best efforts and those of other members of the team, we were unable to get a clear final picture of how rats get access to sweet water in this study.

      So here is my challenge for the interested readers and researchers: I would really appreciate if someone could help me figure out how exactly rats get access to sweet water in this study.

      Thank you!


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    1. On 2014 Sep 10, Suleyman Serdar Koca commented:

      I thank the comment first of all. The evaluation of serum IL-33 levels was not the primary aim of the present study. It was analyzed in limited patients to determine whether IL-33 gene polymorphisms affect serum IL-33 level. However, the detected relations of serum IL-33 level with the clinical signs were reported. Behçet’s disease has complex ethiopathogenesis. Genetic basis of the disease is divergent. Not only patients with different ethnic origins but also each patient has different disease burden. Therefore, the results of cytokines may be divergent in the different cohort.


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    2. On 2014 Aug 26, Kamel Hamzaoui commented:

      Interesting paper. I cannot understand how the authors found similar IL-33 levels in BD patients than in healthy controls (52 patients were studied). They also found increased levels of IL-33 in BD patients with uveitid (32 patients were studied). We found the same increase of IL-33 in BD patients with retinal uveitis. We and others found increased levels of IL-33 in serun, in cerebrospinal fluid and in EN skin lesions measured at the mRNA and immunohistology.

      Our laboratory and the Korean laboratory used the same Kit Elisa, but not the authors. The authors of the paper have to study control disease such as RA, SLE, MS patients.

      Thank you


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    1. On 2017 Nov 12, Gerardo Ferbeyre commented:

      I have red this paper many times and I find always inspiration for experiments and new ideas. The authors condensed a tremendous body of work while keeping their main message beautiful and simple. In pancreatic cancer, inhibition of the RAS/MAPK pathway allows the emergence of a subpopulation of dormant tumor stem cell with increased dependency on mitochondria. We have reproduced many of the key characteristics of these pancreatic cancer stem cells using a different experimental model and I wonder whether this phenotype is unique to these cancer cells when they evolve or whether the cells are reactivating a primitive embryonic program of pancreatic epithelial stem cells.


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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 2014 Aug 27, Ryan Radecki commented:

      Post-publication commentary:

      "Should the 48-hour Cardioversion Window Be Revised?"

      It has become generally accepted practice to treat new-onset atrial fibrillation and atrial flutter with electrical cardioversion in the acute setting – provided the known onset of atrial fibrillation is less than 48 hours. Beyond that, caution tends to be advised – whether through use of transesophageal echocardiography to rule out left atrial thrombus, or through pre- and post-procedural anticoagulation.

      However, this data from a research letter in JAMA suggests – possibly we ought to be even more cautious regarding time-of-onset....

      http://www.emlitofnote.com/2014/08/should-48-hour-cardioversion-window-be.html


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    1. On 2014 Sep 15, Gaetano Santulli commented:

      In this elegant retrospective cohort study Gialdini and colleagues report that among patients hospitalized for surgery, perioperative atrial fibrillation is associated with an increased long-term risk of ischemic stroke, especially following noncardiac surgery. To predict cumulative rates of ischemic stroke the Authors used the CHA2DS2VASc score. Remarkably, in the low-risk categories (score≤1) there are 13 and 9 strokes among patients undergoing cardiac and noncardiac surgery, respectively. The Authors however do not provide any information about baseline electro-, echocardiographic or cerebrovascular assessment for these subjects. Thus, clinical data on potential cardiac (inter-atrial septum defect, mitral valve stenosis, cardiomyopathies) and cerebrovascular alterations, in our opinion essential for interpreting the results provided, are missing. This aspect is particularly relevant since the above-mentioned disorders are functionally related to ischemic stroke (1,2) and might exert pro-thrombotic effects also in low-risk subjects. Moreover, diabetes mellitus has been shown to be an independent risk factor for stroke, including in patients with low CHA2DS2VASc score (3). In this sense, it would be interesting to know the percentage of diabetic patients in the low-risk population. Equally important, a more comprehensive assessment of the baseline coagulation status could be useful: given the lack of data on antithrombotic therapy, acknowledged by the authors in the limitations of the study, it would be helpful to the Reader to know at least the rate of hemorrhagic stroke events.

      References 1. McCabe DJ, Rakhit RD. Antithrombotic and interventional treatment options in cardioembolic transient ischaemic attack and ischaemic stroke. J Neurol Neurosurg Psychiatry. 2007 Jan;78(1):14-24. 2. Finsterer J, Stollberger C. Stroke in myopathies. Cerebrovasc Dis. 2010;29(1):6-13. 3.Marfella R, Sasso FC, Siniscalchi M, Cirillo M, Paolisso P, Sardu C, Barbieri M, Rizzo MR, Mauro C, Paolisso G. Brief episodes of silent atrial fibrillation predict clinical vascular brain disease in type 2 diabetic patients. JACC. 2013;62(6):525-30.

      Celestino Sardu, MD (1), Gaetano Santulli, MD, PhD (2) (1) Second University of Naples, Naples, Italy; (2) Columbia University Medical Center, New York, NY, USA

      Conflict of interest: none.


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

      Please note that these extremely precious specimens in these tiny humans were obtained by trained pathologists, and not neonatologists, pediatricians or radiologists.

      Just as is the case for fine needle aspirates, the best bone marrow specimens with highest diagnostic yields and lowest inadequacy rates come when pathologists themselves take the specimen they are to subsequently analyze.

      There are of course many other issues (logistic, training, regulatory, safety) that are tied up with this fact, but the above, in my experience, is invariable.


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    1. On 2014 Oct 27, Maria Flavia Di Renzo commented:

      As mentioned in the paper and shown in Supplementary Figure 2, we also used different single shRNAs. Actually, we also used five shRNAs specific for different sequences of CDT2 and different from the sequences of the four siRNAs of the pool. We obtained regulation of CDT2 targets and commitment towards cell death in cancer cells but not in normal cells. However, the in-depth analysis of molecular targets and cell cycle was not feasible in cells stably committed to death. Thus we carried out experiments with siRNAs that resulted in similar, but transitory, biochemical and functional effects. In conclusion, we are confident that the observed phenotypes might be attributed to CDT2 suppression.


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    2. On 2014 Oct 17, Eugen Buehler commented:

      The authors cite our paper (Buehler E, 2012) as evidence that “…pools of siRNA targeting different mRNAs, such as those used in libraries, results in increased off-target effects”. Unfortunately, that sentence is not supported by our paper. The method demonstrated in our paper was applied to an arrayed screen of individual siRNAs in which there were no pools, and no conclusions about pooling of siRNAs can be reached from that manuscript. Furthermore, the authors state that “The use of this siRNA pool allows avoiding too high concentration of each single siRNA and thus prevents off-target effects” and cite Jackson AL, 2010 to support this. Again, this assertion is not supported by the cited reference. Jackson AL, 2010 states that “Pooling of multiple siRNAs to the same target may help to reduce off-target silencing, due to competition among the siRNAs in the pool” (emphasis added). No evidence exists to support the claim that pools 3 or 4 siRNAs will prevent off-target effects. To the contrary, we have demonstrated previously that pooling siRNAs does not generate more reproducible phenotypes than single siRNAs (see Marine S, 2012, Figure 1, B and C) and that pools of siRNAs can and do generate many off-target phenotypes, which can then be confirmed by deconvolution of those pools (see Marine S, 2012, Figure 2). Unfortunately, the authors base most of their conclusions on experiments using a single reagent (a pool of four different siRNAs targeting CDT2) and a single non-silencing control. This means that many or all of the phenotypes they observed experimentally may be due to siRNA off-target effects (see Chung HY, 2014 for a case study in how off-target effects can result in false positives). This is not to say that their conclusions are incorrect, only that I believe that RNAi experiments require multiple independently tested reagents and/or matched controls to guard against the false positives due to off-target effects that are so frequent in these experiments.


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    1. On 2014 Aug 28, Frederick K Korley commented:

      Agreed. Troponin values can no longer be used in a dichotomous fashion. Any troponin elevation is a bad troponin elevation. However, those without acute elevations may not necessarily need inpatient hospitalization. If they are discharged, they will benefit from expedited outpatient follow-up.


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    2. On 2014 Aug 27, Ryan Radecki commented:

      Post-publication commentary:

      "Highly Sensitive Troponins – False Positive Bonanza"

      The “highly sensitive” troponin has received a great deal of publicity, hyped ad nauseum, see: “Simple test could help rule out heart attacks in the ER.”

      But, as sensitivity increases – invariably, specificity decreases. However, that is not the fault of the test – it is a failure of clinicians to ask the correct question of the test. When asking “does this patient have an acute myocardial infarction?”(most commonly Type 1 MI in the ED), our training and education has been outpaced by assay technology – the test no longer provides a dichotomous “yes” or “no”.

      http://www.emlitofnote.com/2014/08/highly-sensitive-troponins-false.html


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    1. On 2014 Nov 02, Swapnil Hiremath commented:

      This systematic review, along with its accompanying review was discussed on Oct 21st 2014 in the open online nephrology journal club, #NephJC, on twitter. Introductory comments are available at the NephJC website. It was a great discussion, with more than 20 participants, including nephrologists, cardiologists and residents/fellows from different specialties. 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 investigators and the funding agency (AHRQ) should be commended for attempting to answer these important questions about the role of troponins in patients with chronic kidney disease.

      • Most participants rely on a rise in troponin levels to help diagnose acute coronary syndrome in CKD patients, and were disappointed that no evidence was found to support (or refute) this practice.

      • The adverse prognostic implications of higher troponin levels, especially in asymptomatic CKD patients was thought to be quite concerning and was the subject of much discussion, with many possible therapeutic management options being raised.

      Overall, these reviews answered a few questions, but also brought out many areas where further research needs to be focused. 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 02, Swapnil Hiremath commented:

      This systematic review, along with its accompanying review was discussed on Oct 21st 2014 in the open online nephrology journal club, #NephJC, on twitter. Introductory comments are available at the NephJC website. It was a great discussion, with more than 20 participants, including nephrologists, cardiologists and residents/fellows from different specialties. 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 investigators and the funding agency (AHRQ) should be commended for attempting to answer these important questions about the role of troponins in patients with chronic kidney disease.

      • Most participants rely on a rise in troponin levels to help diagnose acute coronary syndrome in CKD patients, and were disappointed that no evidence was found to support (or refute) this practice.

      • The adverse prognostic implications of higher troponin levels, especially in asymptomatic CKD patients was thought to be quite concerning and was the subject of much discussion, with many possible therapeutic management options being raised.

      Overall, these reviews answered a few questions, but also brought out many areas where further research needs to be focused. 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 Aug 12, Ryan Radecki commented:

      Post-publication commentary:

      "Just Another Advertisement for tPA"

      As with last week's coverage of the updated Cochrane Systematic Review for tPA in acute ischemic stroke, the key question is: what’s new?

      The first pooled meta-analysis, published in The Lancet in 2004, included NINDS, ECASS I, ECASS II, and ATLANTIS. It was subsequently updated in 2010 to add ECASS III and EPITHET. Now, these authors have decided to add IST-3.

      I am actually a huge fan of individual-patient meta-analyses. Depending on the data availability, the similarity of trial protocols, and other issues associated with heterogeneity, this is the gold-standard for aggregating data and increasing power. Individual-patient analyses also allow for more reliable exploration of subgroup effects not otherwise possible through regular meta-analyses or systematic reviews.

      But, at the crux of it, a meta-analysis is only as good as the included trials – and this is a topic much debated over the last twenty years....

      http://www.emlitofnote.com/2014/08/just-another-advertisement-for-tpa.html


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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 2014 Nov 05, Fillip Port commented:

      This paper reports on the use of the H1 promoter to drive expression of gRNAs for CRISPR/Cas genome engineering. The authors demonstrate that gRNAs expressed from H1 can efficiently modify the genome of cultured human cells in conjunction with Cas9 endonuclease. Interestingly, gRNA expression levels from H1 are lower than from the commonly used U6 promoter. Although this can negatively effect mutagenesis rates at the on-target site, it can also increase CRISPR/Cas specificity, as high activity is more likely to lead to off-target effects. This makes the H1 promoter a potentially useful tool for CRISPR/Cas genome engineering in human cells.

      However, the authors suggest that their results have much more general significance by expanding the CRISPR/Cas genome targeting space. This is because the U6 promoter initates transcription at a G nucleotide (although see comment below and reference therein), which according to the authors constrains genomic target sites to GN19NGG. This assertion is surprising as it is common practice in the CRISPR field to target sites that do not start with a G by simply adding a (often mismatched) G to the corresponding gRNA or to replace the first nucleotide with a G to create a gRNA that is mismatched at the first position. The authors acknowledge these strategies in the first paragraph of their discussion, but cite six papers as providing evidence that 5’ extensions or truncations reduce gRNA efficiency. However, these papers in fact provide evidence that 5’ extensions or truncations of a single nucleotide often have no effect on activity and when they do the effect is usually minor (modified gRNAs usually retain >80% activity). Furthermore, the authors do not cite another study that shows that small gRNA truncations retain high activity in the majority of cases and have reduced off-target effects (Fu Y, 2014). Therefore, much of the published evidence suggests that extending or truncating gRNAs by a single nucleotide is well tolerated by the great majority of gRNAs. As a result it is in principle possible to target any genomic site adjacent to a PAM motif with gRNAs expressed from a U6 promoter and hence the H1 promoter, although potentially useful, does not expand the CRISPR target space.


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    2. On 2014 Aug 12, Haoquan Wu commented:

      The preferred initiation nucleotide for U6 promoter are A and G, as we have shown in our study which can be found http://www.nature.com/mtna/journal/v3/n5/full/mtna201412a.html. We also confirmed that gRNAs starting with A can disrupt the target gene at similar level as gRNAs starting with G in the study. H1 promoter is much weaker than U6, which might significantly lower the CRISPR-Cas9 system efficiency.

      It is amazing that the commonly accepted conceptions about U6 promoter initiation and termination are not complete although U6 promoter has been the most commonly used promoters to drive small RNA expression. The commonly accepted conception that the continuous Ts is the termination signal for U6 promoter is also not correct.


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    1. On 2015 Sep 10, Lydia Maniatis commented:

      The authors say that “we assessed whether the highest luminance is mapped onto a fixed surface reflectance (“white”) independently of target reflectance, illumination level (real or simulated), or luminance. ”

      Evidently, by “illumination level” they are referring to the collection of luminances of their “Mondrians,” and by “luminance” they are referring to the luminance of individual target surfaces. It may be that, in relatively low luminance conditions, observers experienced a sense of low illumination, but neither the authors nor anyone else has, to my knowledge, tested whether such an impression does, in fact, arise. The fact that “low illumination” conditions resulted in lower lightness matches for targets actually implies the opposite, since impressions that surfaces are “in shadow” typically cause them to appear lighter than equiluminant. apparently plain view surfaces. So average luminance (regardless of how the investigators achieve this) and contrast are the variables being looked at,

      As is typical in experiments using “Mondrians” or checkerboard stimuli, the authors seem to overlook the fact that these stimuli are capable of producing differential illumination, transparency, luminosity effects, despite the absence of the usual “cues.” This is evident, for example, in checkerboard stimuli used by Allred, Radonjic, Gilchrist & Brainard (2012), who tentatively acknowledge (but do not test for) some but not all of the (self-evident) effects. Anderson et al cite Radonjic, Allred, Gilchrist and Brianard (2011) as having shown that “a stimulus ratio of 5905:1 could be mapped onto an extended lightness ratio of 100:1 and concluded that such results ruled out theories that predict perceived lightness from luminance ratios or Weber contrast” and suggest that “these data cast significant doubt on the view that the visual system has any understanding of the range of reflectance values that populate natural environments.” However, it is not clear that the high-range stimuli in Radonjic et al's experiments did not produce luminosity effects. Their observers did, in fact, report luminosity for the highest luminance values in those stimuli, but the authors discounted those reports as being due to the stimuli having been presented on an “emissive screen.” However, this explanation does not seem credible given that the same luminance values did not produce luminosity reports in lower-range situations.

      If there were apparent scission effects going on in Anderson et al's stimuli, then observer reports would have been affected. When a surface is completed “beneath” a shadow, and seen as homogeneous in its lightness, this does not mean that we can't see that it is also darker at the shadowed place, in the same way that amodally completed surfaces are seen and not seen at the same time. You can't disprove that an amodal completion is occurring simply on the basis of asking an observer to report on the local color in the image at an “obstructed” location. Similarly, simply asking a naive observer to make a lightness match where scission is occurring is problematic.

      It is always important for readers of perception papers to be able to see the stimuli used, so it would have been good if all of the Mondrians, and not just the one, were made available.


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    1. On 2014 Aug 13, Amanda Capes-Davis commented:

      Unfortunately many cell lines are misidentified and do not correspond to the tissue from which they were thought to be established. This is the case here: both HEp-2 and KB are cross-contaminated by HeLa, a cervical adenocarcinoma cell line. For a list of known cross-contaminated or otherwise misidentified cell lines, see http://iclac.org/databases/cross-contaminations/.


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    1. On 2015 Mar 28, Amit Kumar Chowhan commented:

      Dear Sir,

      We read the article by Srikanth S et al.<sup>1</sup> on ‘A comparative study of fine-needle aspiration cytology (FNAC) and fine-needle non-aspiration cytology (FNNAC) techniques in head and neck swellings’ with interest and appreciate the inclusion of multiple organs i.e. lymph node, thyroid and salivary gland located in head and neck region in the study. Although fine needle aspiration cytology is a well-established tool as a first line diagnostic modality, however, a major criticism pertains to its use in highly vascular organs such as thyroid and liver, or in haemorrhagic lesions where large quantities of blood compromise cytologic interpretation. Hence we agree with the authors when they excluded lesions of vascular origin from their study.

      We agree with the authors that FNNAC allows greater ease of sampling with better control of the hand during the procedure and a good perception of the lesion consistency, enabling more precise entry into the mass and thus is more user friendly. Apart from being less traumatic and painful to the patient, as suggested by the authors, we would like to add that with this technique the patient would also be less apprehensive about the procedure, when a large syringe with needle and a syringe holder is not seen, thus making FNNAC more patient friendly. Another advantage of FNNAC is that the syringe is used to expel the material after the procedure is completed, whereas in FNA it is used to create a suction force to aspirate the cells in to the needle. A fresh sterile syringe is therefore not necessary for FNNAC, thus reducing the cost of procedure.

      In their study the authors concluded that for thyroid lesions the non-aspiration technique was better than aspiration technique with respect to all the five parameters proposed by Mair et al.<sup>2</sup> i.e. background blood/clot, amount of cellular material, degree of cellular degeneration & trauma and retention of appropriate cellular architecture. In a similar study conducted by us<sup>3</sup> on thyroid lesions, we found that the non-aspiration technique was better in relation to all the parameters except for amount of cellular material, which was better with aspiration technique. In cases of colloid goiter, brownish colloidal fluid drained out immediately on putting needle and drenched the fingers holding the needle. This problem was handled by keeping a syringe ready, which was immediately attached to the needle and the fluid collected in the syringe – to be cyto-centrifuged for better cellularity. Another problem encountered was for calcified nodules, which required vigorous aspiration, as it didn’t yield any material on non-aspiration. We therefore, would recommend first non-aspiration technique to be performed and if the material obtained is insufficient then only to go for another pass with aspiration technique.

      References:

      1.Srikanth S, Anandam G, Kashif MM. A comparative study of fine-needle aspiration and fine-needle non aspiration techniques in head and neck swellings. Indian J Cancer 2014;51:98-9.

      2.Mair S, Dunbar F, Becker PJ, Du Plessis W. Fine needle cytology - is aspiration suction necessary? A study of 100 masses in various sites. Acta Cytol. 1989;33:809-13.

      3.Chowhan AK, Babu KV, Sachan A, Rukmangdha N, Patnayak R, Radhika K, Phaneendra BV, Reddy MK. Should we apply suction during fine needle cytology of thyroid lesions? A prospective study of 200 cases. Journal of Clinical and Diagnostic Research 2014;8:19-22.


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    1. On 2014 Sep 01, Amanda Capes-Davis commented:

      The KB cell line is often used to test therapeutic activity against cancer. But although KB comes from cancer, it is not oral squamous cell carcinoma. KB is known to be cross-contaminated with HeLa and is actually cervical adenocarcinoma. For a list of known cross-contaminated cell lines, see http://iclac.org/databases/cross-contaminations/.


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    1. On 2014 Aug 18, David Keller commented:

      Ibuprofen, but not other NSAID's, is associated with decreased risk of Parkinson's disease

      Ibuprofen use has also been observed to be strongly associated with a lower risk of incident Parkinson's disease (1). Other NSAID's, such as naproxen, have not showed any such apparent protective effect (2). Given that long-term use of NSAID's "such as ibuprofen" has been observed to be associated with "reduced risk and delayed onset of Alzheimer's disease", I would be cautious about substituting a different NSAID, such as flurbiprofen, unless it has also demonstrated the same associations with reduced Alzheimer's risk, because the epidemiological studies of NSAID use and Parkinson's risk have indicated that, when it comes to the risk of neurological degeneration, different NSAID's can have vastly different effects.

      References

      1: Gao X, Chen H, Schwarzschild MA, Ascherio A. Use of ibuprofen and risk of Parkinson disease. Neurology. 2011 Mar 8;76(10):863-9. doi: 10.1212/WNL.0b013e31820f2d79. Epub 2011 Mar 2. PubMed PMID: 21368281; PubMed Central PMCID: PMC3059148.

      2: Driver JA, Logroscino G, Lu L, Gaziano JM, Kurth T. Use of non-steroidal anti-inflammatory drugs and risk of Parkinson's disease: nested case-control study. BMJ. 2011 Jan 20;342:d198. doi: 10.1136/bmj.d198. PubMed PMID: 21252104; PubMed Central PMCID: PMC3023971.


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    1. On 2014 Aug 22, Mangesh Thorat commented:

      Response to Hilda Bastian’s recent comment:

      Thank you for the continued discussion. Individual studies like PHS did report a 5-year follow-up, which is not uncommon. Rothwell’s recent overview (Rothwell PM, 2012) did look at studies with shorter follow-up, but the central question in this overview was aspirin’s effect on incidence. The effect on incidence starts to appear at 3 years, while that on mortality takes about 5 years. On the other hand, for example, the endpoint Seshasai SR, 2012 used was mortality and not incidence and therefore they could not observe a significant reduction. Sutcliffe P, 2013 looked at all these data and treated them as equal. Additionally, they did not have access to updated WHS results that showed a significant reduction in CRC. This resulted in their excessive perception of uncertainty; it is prominently reflected in their interpretation.

      We believe that most experts agree that "the evidence supporting aspirin's benefits on cancer is now overwhelming.", the differences in opinion probably only exist for the magnitude and site-specific effects (e.g. 3 of our co-authors). This is the reason we provide several sensitivity analyses that use lower magnitude of benefits, higher magnitude of harms and also lack of effect on certain cancer sites. All these show a net benefit.

      We agree that long-term harms should not be easily dismissed, but we believe that the severity of harms also needs to be considered in any assessment. In our assessments, we have erred on the side of caution and very likely over-estimated the harms. Individual circumstances differ, and therefore we believe that a careful assessment by and an informed discussion with a healthcare professional is necessary.

      We also look forward to the new USPSTF review as we have been informed that on this occasion USPSTF will look at the overall picture by assessing impact on all diseases/conditions affected by aspirin and not just single disease/disease group.

      Response to David Colquhoun’s comment:

      Please note that the NHS Choices comment has been amended to delete the unsubstantiated statement about our study being ‘not reliable’. As stated in the paper this was a benefit-harm analysis based on very recent systematic overviews by some of our co-authors, so it was not necessary to repeat them.


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    2. On 2014 Aug 16, Hilda Bastian commented:

      Thanks for replying, Mangesh Thorat. I didn't review the primary studies, so hadn't picked up the error in Sutcliffe P, 2013 with respect to the Women's Health Study (Cook NR, 2013). The concern remains valid, as it applies to most of the evidence.

      I disagree, though, that the Sutcliffe review has a "major flaw," considering all studies equal irrespective of follow-up. Their analyses for duration of follow-up are front and center. And they specifically report on, and discuss, 20-year analyses on colorectal cancer, in coming to their conclusions.

      Nor are they the only group in this field to consider studies with shorter follow-up (see for example Rothwell PM, 2012). And the Physicians' Health Study (Steering Committee of the Physicians' Health Study Research Group., 1989) had 5-year follow-up.

      Many people agree with your statement that "the evidence supporting aspirin's benefits on cancer is now overwhelming." But many do not. The National Cancer Institute's recent round-up (NCI, 2014) considers perspectives on the same body of evidence. NCI highlights "mixed opinions" and "reasons for caution."

      While the potential for important net benefit from daily low-dose aspirin for more people is vitally important, I don't think the issue of harms of longterm use should be too easily dismissed. People who have common conditions that are potentially affected by taking aspirin daily (like asthma (Morales DR, 2014)), or at high risk of developing ARMD from mid-life, or whose concomitant medication use may be a relevant consideration (such as with arthritis (Colebatch AN, 2011)) might well want less uncertainty about what this means for them.

      Given the differing interpretations of this body of evidence, the findings of the US Preventive Services Task Force review, expected this year, will be interesting (NCI, 2014).


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    3. On 2014 Aug 15, Mangesh Thorat commented:

      We thank Hilda Bastian for her comment, our response to the points raised is given below:

      Sutcliffe P, 2013's systematic review is not discussed in Cuzick J, 2015 because we believe that it has a major flaw; it considered all reviews to be equal irrespective of the length of follow-up. For example, the review by Seshasai SR, 2012 that failed to show any cancer benefit had a follow-up of only 6 years. As it takes 5 years for aspirin’s beneficial effects on mortality to appear, inclusion of such data by Sutcliffe P, 2013 resulted in underestimation of beneficial effects on cancer. The updated results of WHS (Cook NR, 2013), which showed 42% reduction in CRC incidence were published almost at the same time as Sutcliffe P, 2013, and therefore were not included in this review. Sutcliffe P, 2013 based their interpretation on earlier WHS results (Cook NR, 2005), which did not show any reduction in CRC.

      Sutcliffe P, 2013 also were under wrong impression that all the primary studies and meta-analyses for benefit "assessed reduction in cancer incidence and mortality retrospectively through re-analysis of RCTs of aspirin for primary prevention of CVD." Cancer incidence and mortality is one of the primary endpoints in the WHS (Cook NR, 2013). The importance of WHS lies in the fact that it not only confirmed the benefit in cancer as a primary endpoint, even with alternate day low dose, but also confirmed that there is a long lead time and a prolonged carry-over benefit. This is where the recent WHS publication (Cook NR, 2013) differs from results published earlier (Cook NR, 2005).

      We also disagree with the statement that “uncertainty around the cancer estimates remains high”, a very large body of evidence from observational studies (Bosetti C, 2012; Algra AM, 2012) is consistent with the findings from RCTs and should not be ignored as done in Sutcliffe P, 2013. The evidence supporting aspirin’s benefits on cancer is now overwhelming with over 200 published studies and those with adequate follow up showing very consistent evidence for a reduced incidence and mortality of three major digestive track cancers – colon, stomach and oesophagus.

      It is clear from the evidence that the harms associated with aspirin (and the cardiovascular benefits) begin at the time of use and cease with stoppage of drug use. However, cancer benefits have a lead time before becoming apparent, but these continue for a long period after stopping drug use; a long carry-over effect as seen with other preventive drugs like tamoxifen. With this understanding, mere pooling of data from meta-analyses and trials with variable treatment durations and variable post-treatment follow-up to assess benefit and harms, as Sutcliffe P, 2013 have done is not a reliable method for assessing the impact of aspirin. This is primarily where our work and therefore the results differ.

      In addition, we have modelled benefits and harms of aspirin for the average risk population using actual event rates in the general population to give estimates of the impact of aspirin specifically for this group, which is the major focus of our work.

      We accept that the question of aspirin’s impact on ARMD is unresolved, but ARMD is uncommon (National Eye Institute) below 70 years of age, which again is the group on which we have focussed our attention.


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    4. On 2014 Aug 10, Hilda Bastian commented:

      These authors (Cuzick J, 2015) come to a more positive conclusion about the state of the evidence on routine aspirin use and cancer prevention than do Sutcliffe P, 2013 (also reported at Sutcliffe P, 2013).

      Sutcliffe P, 2013 undertook a thorough and well-reported systematic review of the evidence, based on previous systematic reviews, the primary studies in them, and the relevant RCTs published post-2008, re-analyzing the primary study data. They took into account the same individual patient data and other meta-analyses on which Cuzick J, 2015's interpretation of benefit rely. (Sutcliffe P, 2013's systematic review is not discussed in Cuzick J, 2015.)

      The main data included in Cuzick J, 2015 but unavailable to Sutcliffe P, 2013 appear to be an analysis of harms (where insufficient detail on the sources or selection process have been published), and a long-term follow-up report from the Women's Health Study (Cook NR, 2013). However, as Cook NR, 2013 shows a broadly similar outcome to the <10 year results (no effect on total cancers, but an effect on colorectal cancer only), this does not appear to account for the difference in interpretation of the state of the evidence by these two groups.

      The main data relied on in Sutcliffe P, 2013 that differ to those in key analyses of Cuzick J, 2015 are the Physicians' Health Study (Steering Committee of the Physicians' Health Study Research Group., 1989) and the Women's Health Study (Ridker PM, 2005). These are of long-term aspirin use on alternate days, rather than daily. These two studies include around 62,000 people, and Sutcliffe P, 2013's analyses show they dominate several calculations.

      Sutcliffe P, 2013 point to a critical issue: all the primary studies and meta-analyses for benefit "assessed reduction in cancer incidence and mortality retrospectively through re-analysis of RCTs of aspirin for primary prevention of CVD." They conclude that the uncertainty around the cancer estimates remains high, and the "long term all-cause mortality data does not provide a compelling case for aspirin protection against CVD and cancer mortality."

      With further trials underway, the picture may become clearer in the next few years. While previous trials and analyses address the major harms associated with long-term daily aspirin use (hemorrhagic stroke and gastrointestinal bleeding), many people considering this intervention may also be concerned about additional outcomes. For example, the still-unresolved question of any potential impact on neovascular age-related macular degeneration (Klein BE, 2012, Liew G, 2013, Christen WG, 2014).


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    1. On 2014 Aug 13, Amanda Capes-Davis commented:

      This study looks at laryngeal carcinoma, using patient tissue and a cell line model. Please be aware that the cell line used here, HEp-2, is not from laryngeal carcinoma. HEp-2 is cross-contaminated with HeLa and is actually cervical adenocarcinoma. For a list of known cross-contaminated cell lines, see http://iclac.org/databases/cross-contaminations/.


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    1. On 2014 Aug 28, Mohammad Rostami Nejad commented:

      I read with interest the paper by Rahmati et al. entitle” Correlation of Tissue Transglutaminase Antibody with Duodenal Histologic Marsh Grading” which retrospectively reviewed hospital files of 159 patients with available tTG titer and pathology reports in the gastrointestinal clinic of Firoozgar Hospital, Tehran, Iran. They reported that the mean tTG titers was significantly higher in patients with Marsh III (a-c) and more than 9 folds higher than the kit’s cut-off value. In their conclusion they said that small intestinal biopsy should always be considered in case of high clinical suspicion, regardless of the results of serologic testing and I personally not agree with this statement. New guidelines confirmed that celiac disease diagnosis in children can be made on the basis of clinical signs, serology and genetics without the need of biopsy. Therefore, in my opinion HLA typing is useful tool for this matter and can be used as diagnosis tool for celiac disease and we can avoid invasive procedures like endoscopy in these cases.


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    1. On 2014 Aug 10, Ryan Radecki commented:

      Post-publication commentary:

      "Bizarrely Alarmist Pediatric URI Study"

      In our new Gawker and Buzzfeed-fueled, short-attention span reality, attention-grabbing headlines are essential. So, let me come up with the modern headline for news coverage of this latest article, published in Pediatrics: “Is your child's next cold a killer?”

      Seriously, as covered by Medscape (subscription required): “As many as 1 in 3 children seeking treatment in the emergency department for influenza-like illnesses (ILI) at the peak of influenza season are at high risk of suffering severe complications, such as pneumonia.”

      But, that’s hardly the case....

      http://www.emlitofnote.com/2014/08/bizarrely-alarmist-pediatric-uri-study.html


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    1. On 2014 Aug 12, Jacob Puliyel commented:

      I congratulate the authors of this analysis. However their analysis begs more questions than it answers.

      They found that there were 581 cases of ultrasound diagnosed intussusception per 100,000 child years, during the Rotavirus trial, which works out to be 1 intussusception in every 172 children, each year, or 1 intussusception for every 86 children who were followed up for 2 years in the study (approximately - not counting 6 weeks before vaccination).

      Bhandari et al Bhandari N, 2014 have reported that 40 babies have to be vaccinated to prevent one severe rotavirus gastroenteritis episode (NNT = 40) in the 2 year of study.

      The analysis by Jehangir et al Jehangir S, 2014 of data from the Rotavirus vaccine trial showed that 1 in every 86 babies in the trial: 1) developed symptoms and signs of intussusception confirmed by a study pediatrician (namely pass blood in stools, or have continuous vomiting, abdominal distension or abdominal lump) and 2) had the diagnosis of intussusception confirmed on ultra sound.

      About half the cases resolved spontaneously. In field conditions, the other half will need urgent radiographic reduction or surgery and if these are not available (in remote villages where the vaccine will be administered), mortality is near 100%

      Jehangir and colleagues report intussusception in the study sample, without differentiating the babies who received the study drug (rotavirus vaccine) from those who received placebo. This differentiation is crucial because the rate of intussusception in the controls can be assumed to be the natural rate of intussusception using the surveillance methods described in the study.

      As the study has now been analysed after unmasking the vaccine recipients, this data on how many among the trial drug recipients and how many among the placebo recipients developed (ultrasound proven)intussusception, should be provided on the PubMed Commons. From this we can determine the NNT for intussusception (numbers of babies that need to be vaccinated to cause intussusception in 1 child) The authors need to publish data on the number of ultrasound diagnosed intussusception per 100,000 child years among those who received rotavirus vaccine and the corresponding figure for placebo recipients.

      Instead of this comparison, the authors do a retrospective analysis of data on intussusception treated at their tertiary referral hospital, between 1 January 2010 and 31 August 2013.

      Only babies who had intussusception that needed surgical or radiological treatment and which was confirmed on ultrasound examination, were included.

      Thus only cases qualifying as intussusception at Level 1 diagnostic certainty, were included and all those whose intussusception resolved spontaneously (without medical intervention) were excluded from the retrospective study.

      Under these circumstances it is meaningless to assert that all the babies selected for analysis in the retrospective study needed some intervention but only about 44% of those that were identified in the rotavirus vaccine-trial-active-surveillance, needed intervention.

      The authors then go on to conclude that, as 56% of babies with ultrasound diagnosed intussusception in the vaccine trial recovered spontaneously, active surveillance is not a good method to detect adverse events following immunization, and that sentinel hospital based surveillance (for post marketing surveillance after rotavirus vaccine introduction) was better.

      The rationale for this conclusion is difficult to fathom. Children who come to tertiary centers (and sentinel surveillance hospitals) with intussusception usually survive. It is the babies in remote areas, far away from roads and transport who die untreated and undiagnosed after intussusception.

      The sentinel surveillance will have no record of these cases of intussusception or deaths. Their deaths will not even be counted using the WHO recommended strategy of sentinel hospital based surveillance. That is the big tragedy.


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    1. On 2014 Aug 12, Jacob Puliyel commented:

      I read with interest this paper that describes efficacy and safety of the 116E rotavirus vaccine in the 2nd year of the trial. The results for the first year were published earlier in June 2014 Bhandari N, 2014. The authors need to be congratulated for this study.

      However some of the data appears incongruous. According to the clinical trial registry http://clinicaltrials.gov/show/NCT01305109 one of the secondary outcome measures was to be "safety of ORV 116E for intussusception events [Time Frame: Up to 2 years of age] Safety of ORV 116E for intussusception events in comparison to a placebo will be assessed in all subjects, from day of 1st dose till the age of 2 years (24 months) + up to 14 days". The term used here is 'intussusception events' not specifically only cases with Level 1 certainty.

      The multicenter trial was conducted in 3 centers at Delhi, Pune and Vellore. The study was done in 6799 infants of whom 4532 received the 116E rotavirus vaccine and 2267 received placebo. In the Vellore limb of the study 1000 received the vaccine and 500 were given placebo.

      Bhandari N, 2014 reports that 8 babies developed intussusception (intussusception by Brighton Level 1 criteria) during the 2 year follow up . However Jehangir et al, in the same issue of the journal Vaccine Jehangir S, 2014 report that there were 16 cases of intussusception (diagnosed on ultrasound) in the 1500 infants followed up at Vellore. 7 of these required radiological reduction meeting Brighton criteria level 1.

      It seems unlikely that there were 16 children with intussusception in Vellore center (7 meeting level 1 criteria) and there were only 11 cases in the entire trial. This would mean that there were 7 cases (meeting level 1 criteria) in Vellore among 1500 children studied and only 4 case among the 5041 children at Delhi and Pune. In view of this, I will request the authors to report in the PubMed Commons how many babies in the two group (vaccinated and placebo group) had intussusception (any level of diagnostic certainty by Brighton criteria ) and how many had Level 1, Level 2 and Level 3 certainty.


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    1. On 2014 Aug 15, Jacob Puliyel commented:

      Licensing the vaccine for general use (in remote areas of India), seems impossible to justify

      I commend Dr John and colleagues for this report on the trial with the 116E Indian rotavirus vaccine. However the authors limit their discussion to comparisons with the trials of Rotarix and Rotateq which recruited some 60,000 patients each. It will be more useful to compare the 116E trial safety results with the RotaSheild vaccine trials http://www.path.org/vaccineresources/files/RotaShield_Fact_Sheet_CDC.pdf.

      RotaSheild trial

      The RotaSheild trial recruited double the numbers recruited in the present 116E study. RotaSheild was licensed after the trial involving 14,687 patients (10,054 received the rotavirus vaccine and 4,633 received placebo). In the study there was one case of intussusceptions among the 4633 receiving placebo. This suggests that the ‘normal rate of intussusception’ was approximately 2/10,000, in that population. Five cases of intussusceptions occurred among 10,054 RotaSheild vaccine recipients. Thus there were an excess of 3 cases of intussusceptions for each 10,000 children vaccinated. All the intussusceptions were among infants who received a second or a third dose of vaccine. The difference between the vaccinated and placebo recipients was not statistically significant http://www.path.org/vaccineresources/files/RotaShield_Fact_Sheet_CDC.pdf.

      116E Trial

      With the 116E vaccine trial there were 6 cases of intussusceptions in 2267 controls which works out to be 2.6 cases per 1000 placebo recipients. The ‘normal rate of intussusception’ in this study was at least 10 times higher than the RotaSheild trial (where it was 0.2 cases per 1000 placebo recipients). There were 17 cases of ultrasound confirmed intussusceptions among the 4532 given the 116E vaccine which is 3.75 cases per 1000 babies vaccinated. The comparative figure for the RotaShield study was 0.5 cases/1000. In the 116E trial there was an excess of 1 case of intussusceptions for every 1000 children vaccinated with the rotavirus vaccine (compared to the RotaSheild trial where there were 3 excess intussusceptions per 10,000 vaccinated). RotaSheild vaccine was withdrawn after licensing, on account of unacceptable risk of intussusception. The risk of intussusception in the 116E trial was three times higher than with the RotaSheild trial. We are told that in the 116E trial, 50% intussusceptions diagnosed by ultrasound, resolved spontaneously John J, 2014. In the remaining 50% there is need for urgent treatment by a radiologist or pediatric surgeon. In remote parts of India, without motorable roads, let alone radiologists and pediatric surgeons, mortality will be near 100% http://emedicine.medscape.com/article/930708-overview. Such specialized care (radiological or surgical reduction of intussusception) is not available in vast swathes of India and we can assume vaccinated babies would die at home passing blood and mucus in the stools and it will be presumed they had died of dysentery and sepsis rather than intussusception caused by the vaccine.

      Intussusception risks compared to diarrhea deaths avoided

      Assuming only 50% ultrasound diagnosed intussusceptions need urgent treatment John J, 2014 we can assume that one child in 2000 vaccinated babies will develop this life threatening condition. The possible harm in remote areas (deaths from intussusceptions 1/2000) is not offset by benefits (diarrhea deaths avoided using the 116E vaccine).

      In the first two years after vaccination, there number of infants that needed to be immunized to prevent one episode of rotavirus diarrhea of any severity was 21 Bhandari N, 2014. Assuming mortality from rotavirus diarrhea to be 1% in the first 2 years of life with community management Lal S, 1994 Kosek M, 2003 2100 babies will have to be vaccinated to prevent one death from diarrhea in the first 2 years of life.

      When 2100 babies are vaccinated to prevent that 1 death from rotavirus diarrhea - 1 child will have intussusceptions and die in remote areas of the country. This is why, given the limited evidence of this 116E trial, licensing the vaccine for general use (in remote areas of India), seems impossible to justify.


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    1. On 2016 Jul 21, Jacob H. Hanna commented:

      Theunissen et al. Cell Stem Cell 2014 reported absolute failure to detect human naïve PSC derived cell integration in chimeric mouse embryos obtained following micro-injection into mouse blastocysts, as was reported for the first time by our group (Gafni et al. Nature 2013). However, the authors failed to discuss that imaging and cell detection methods applied by Theunissen et al. Cell Stem Cell 2014 were (and still) not at par with those applied by Gafni et al. Nature 2013.

      Regardless, we find it important to alert the readers that Theunissen and Jaenisch have now revised (de facto, retracted) their previous negative results, and are able to detect naïve human PSC derived cells in mouse embryos at more than 0.5-2% of embryos obtained (Theunissen et al. Cell Stem Cell 2016 - Figure 7) Theunissen TW, 2016 < http://www.cell.com/cell-stem-cell/fulltext/S1934-5909(16)30161-8 >. They now apply GFP and RFP flourescence detection and PCR based assays for Mitochondrial DNA, which were applied by the same group to elegantly claim contribution of human neural crest cells into mouse embryos (albeit at low efficiency (Cohen et al. PNAS 2016 Cohen MA, 2016).

      While the authors of the latter recent paper avoided conducting advanced imaging and/or histology sectioning on such obtained embryos, we also note that the 0.5-2% reported efficiency is remarkable considering that the 5i/LA (or 4i/LA) naïve human cells used lack epigenetic imprinting (due to aberrant near-complete loss of DNMT1 protein that is not seen in mouse naive ESCs!! http://imgur.com/M6FeaTs ) and are chromosomally abnormal. The latter features are well known inhibitors for chimera formation even when attempting to conduct same species chimera assay with mouse naïve PSCs.

      Jacob (Yaqub) Hanna M.D. Ph.D.

      Department of Molecular Genetics (Mayer Bldg. Rm.005)

      Weizmann Institute of Science | 234 Herzl St, Rehovot 7610001, Israel

      Email: jacob.hanna at weizmann.ac.il

      Lab website: http://hannalabweb.weizmann.ac.il/

      Twitter: @Jacob_Hanna


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    1. On 2014 Oct 29, Benoit Kornmann commented:

      The unfolded protein response (UPR) is a conserved pathway that senses stress in the endoplasmic reticulum (ER) and responds to it by eliciting a transcriptional response. Mechanistically, when the stress sensor IRE1 is activated by the accumulation of unfolded proteins in the ER, its cytosolic RNAse domain cleaves the messenger of a transcription factor (Xbp1 in mammals, Hac1 in yeast) at two precise positions, removing an inhibitory intron. The 5' and the 3' parts of the messenger are then re-ligated together, to encode a functional transcription factor that takes part in the response. While the ligase involved in the last processing step was known in yeast, it evaded identification for years in mammals.

      Here, the mammalian ligase is identified using a clever trick. A synthetic construct consisting of a Cre recombinase fused to Xbp1 is not expressed in normal conditions, but upon ER stress, Xbp1 is spliced and Cre recombinase is produced. The induction of the recombinase can be easily monitored using a Cre-induced proapoptotic factor, which kills the cells. Using this synthetic circuit, the authors screen a lentiviral RNA interference (RNAi) library and identify hits that fail to induce Cre upon acute ER stress, by simply scoring for survival. They identify the ligase RtcB, which, as with the yeast UPR ligase Trl1, is also involved in tRNA splicing.


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    1. On 2014 Nov 26, Marc Girard commented:

      By the distance between what it demonstrates and what it claims, this paper (as well as the preceding IOM report this one is supposed to update) illustrates that the issue of vaccines safety is still a matter of serious concern for anyone endowed with a minimum of expertise in drug safety or pharmacoepidemiology.

      To start with methodological consistency, one may wonder why the McHarm instrument used by the authors to assess the quality of the reviewed studies was not published in a peer-reviewed journal (the internet link given by the authors [their ref. 7] being not accessible) whereas the only investigations they included had to be published (in contrast with Cochrane reviews which, inasmuch as possible, also take into account unpublished investigations). This inconsistency in the authors’ way of referencing sources exposes their review to a number of biases which are well known in general, but reach unparalleled levels as far as vaccines are concerned. To take just one example, the Ascherio et al.’s study, which suggested a lack of neurotoxicity with hepatitis B vaccination, was triumphantly published in The New England Journal of Medicine (2001;344:327-32) (despite its worrying biases, some of them detailed in further correspondence) with an accompanying editorial celebrating the study as a milestone, whereas, in spite of the professional fame of its authors and of its intrinsic quality, a later study on the same subject by Hernan et al., which suggested opposite conclusions, was first rejected by The NEJM, The Lancet, The BMJ (personal communication), before being published in Neurology (2004;63:838-42) with an accompanying editorial contending that nothing significant had changed regarding the safety of this immunization: as a matter of fact, Hernan was a co-writer of both studies… Another example of selective assessment, extracted from Maglione et al.’s paper itself: it remains unclear why the study by Gallagher and Goodman (which suggests a link between hepatitis B vaccine and autism) would display “high risk of bias and low quality”, whereas the “protective effect [of some vaccines] against acute lymphoblastic leukemia” does not deserve the slightest word of caution… Dozens of additional examples of publication biases could be cited: this is the personal experience of anyone working in the field of vaccines that positive results or enthusiastic reviews are far more easily published than negative investigations or critical comments. Finally and as a number of respected authors have already emphasized, a major part of vaccines studies are performed or supported by manufacturers or governmental agencies responsible for previous recommendations, a situation which clearly maximizes conflicts of interests.

      Regarding now experimental designs in vaccine studies, the following list of methodological defects is concerned with safety assessments (but could be easily extended if efficacy issues were also concerned).

      i) During development, use of false placebos as comparators (i.e. not devoid of pharmacological effects: adjuvants, other vaccines) is a frequent practice.

      ii) Compared to the supposed duration of the beneficial immunological effects of the tested vaccines, the duration of the safety studies aimed at assessing a potential for delayed immunological hazards is often ridiculously short.

      iii) Required on a standard regulatory basis with any new pharmacological entities, the interactions studies are weak, scarce, if not nonexistent with vaccines, whereas most of them are now administered as combinations.

      iv) Likewise, the dose-ranging studies are generally defective, accounting for impressive changes in the booster recommendations once the vaccine is on the market, which would be inconceivable for any other drug.

      Overall and as far as safety issues are concerned, Cochrane reviewers (e.g. in their reviews of flu vaccines) frequently identify blatant weaknesses in available studies which, apparently, are beyond of the reach of the McHarm instrument… On the contrary, Maglione et al. expressed frequent reservations about the “the strength of evidence” suggesting potential safety issues, but none about the power of the reviewed studies to effectively grasp evidence of vaccine hazards… Likewise, the authors are clearly not concerned with the tremendous tendency of vaccine studies (pre- or post-marketing) to underreport adverse events: experience suggests that physicians have a worrying reluctance to accept that vaccines might have adverse effects and, besides their indisputable tendency to brush aside any such suggestions from their patients, they do not hesitate to present as reassuring that “immunizations are up to date” when confronted with an unexplained disease, without even considering that these immunizations could have triggered the disease in question… Another illustration of the same bias: when reassuring, VAERS data are unchallenged, whereas the shortcomings of the system are immediately pointed out each time they may suggest a safety problem…

      Maglione et al.’s review is regrettably silent on two crucial issues of the continuous extension of immunizations against trivial diseases:

      i) maybe acceptable for one vaccination against a severe disease, the autoimmune risk related to the administration of foreign material increases arithmetically when vaccinations are multiplied beyond any sound limit;

      ii) extended immunizations greatly alters the natural ecology of a number of infectious diseases (e.g. measles), a situation the assessment of which would be far more complex than the basic inventory of straightforward side-effects which, as mentioned above, is already severely defective from a methodological point of view: no reason to believe that vaccine promoters are better in complex assessments than in trivial ones…

      As is easy to document, the never-ending extension of immunizations against anything is based upon the dramatization of anecdotic stories, sometimes tragic but fairly rare or even exceptional at a community scale. Yet, experience of drug assessment suggests that below frequencies of, at best, 1-2% of exposed patients, clinical trials fail to identify drug side-effects with a minimum of reliability (the statistical power of postmarketing surveillance being even lower by far). In a country like the USA, this detection threshold is consistent with a shadow area on iatrogenic risk of about 40,000-80,000 persons per vaccine for each vaccinated class of age: it should be obvious that risk-taking of such a size is simply disproportionate to the potential benefits of reducing the morbidity of trivial diseases (even taking into account the natural tendency of vaccine promoters to exaggerate the efficacy of immunizations…). The stubborn obfuscation of this evident arithmetical imbalance by health professionals or governmental agencies suggests that there is something rotten in the kingdom of immunization…

      Marc GIRARD, MSc, MD


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    1. On 2014 Aug 04, Paul Brookes commented:

      This paper addresses a very important point... namely, one of the proposed mechanisms by which ischemic preconditioning (IPC) is thought to bring about cardioprotection. It has been hypothesized that increased leakiness of the mitochondrial membrane to protons may lead to a lowering of ROS generation. We provided some evidence to support increased H+ leak in IPC in 2006 Nadtochiy SM, 2006. Unfortunately, it's not immediately clear to me exactly how the authors measured H+ leak in this study, and also whether their ROS measurements were performed correctly.

      First proton leak: The normal way this is determined is to make simultaneous measurements of membrane potential and respiration in a single chamber equipped with an oxygen electrode and another electrode sensitive to a lipophilic cation such as TPP+. The authors are to be commended on their choice to use a TPP+ electrode, which instantly makes this paper more quantitative than others using qualitative fluorescent probes such as TMRE. They measured membrane potential (as reported in Figure 3) using succinate as a substrate for complex II, with rotenone to inhibit complex I. All good so far. However, normally oligomycin is added to inhibit the ATP synthase as a potential source of leak. In addition nigericin is added to equilibrate K+/H+ and thus ensure the potential is a measure of protonmotive force. As such, the potential measured here was not in a true state 4 condition which is typically required for quantitation of proton leak.

      After describing membrane potential measurements, the methods section describes respiration and H+ leak methodology. It appears oligomycin was added this time (good!), but then something very odd happens... it is stated that "H+ leak was measured as the state 2 respiration rate required to maintain membrane potential at -150mV". Nowhere is it stated how that value of 150mV was arrived at. Normally, when doing these measurements, you set the mitochondria in state 4 (succinate, rotenone, oligomycin, nigericin), and then titrate the activity of the respiratory chain with an inhibitor such as malonate. Step-wise titration then gives you a series of membrane potential and respiration traces, a curve, from which the leak rate at any given potential can be read off. The question is, if such curves were made, how were they made (no mention of malonate anywhere), and why aren't they shown in the paper? The scary alternative explanation may be that they "measured" leak by imposing the 150mV membrane potential by titrating in uncoupler. This is incorrect - you can't add something that changes the leak as a way of measuring the leak. The other odd thing is that the average baseline membrane potential in the IR group barely above 150mV, so some replicates in that group must have had a potential value below 150mV to begin with. How did they authors get those mito's UP to 150mV for the leak measurement? Overall, it would be a whole lot better if they just showed the full leak curves.

      What about ROS? The problems here are two-fold. First it appears that SOD was not added to the incubations to scavenge any stray superoxide and turn it into H2O2 for the assay to pick up. Second, the calibration of the assay was performed incorrectly. It is stated in the methods that the signal was calibrated by "adding known concentrations of H2O2 to buffer solution containing horseradish peroxidase and Amplex-Red" The problem is, it is necessary to calibrate in the presence of mitochondria, so the signal you measure with the calibrating H2O2 is under the same condition as the measurement itself. The way this is commonly done is to just add a bolus of H2O2 at the end of each run. This has the advantage of making every run internally calibrated, which cuts down on noise (this is a very noisy assay). The outcome here is a bit odd... the values of H2O2 generation are in the range of 10-40 nM/min/mg protein. Ignoring the odd units (rates of things should be expressed in moles not Molar), let's assume they meant to write nmols/min/mg - that would put their rates about 1500-fold greater than typical for these conditions (e.g.Chen Q, 2003).

      So, TL/DR - good ideas, but more info' is needed on the proton leak method, and the ROS numbers are just wild. Also, lest anyone think I'm attacking this work because I happen to be one of the people who originally proposed proton leak --> lower ROS --> protection in IR injury, that's not the case. In-fact, my lab' is now pursuing a completely different downstream signaling mechanism, as a mediator of the protective effects of mitochondrial uncoupling, so if the results of this paper are true, my life just got a whole lot easier! I just want to be sure before I start citing it.


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    1. On 2014 Sep 09, Vahid Rakhshan commented:

      Reply to the author’s response: Statistical errors in a recent article: Sella Turcica in patients with Type 1 diabetes

      1. The authors kindly stated in the authors’ reply that it was clearly written in the 4th paragraph of Methods that how the subjects were matched: "This was clearly defined in the 4th paragraph of Material and Methods section. In addition, the need to match the groups according to bone age, not the chronological age was discussed briefly in Discussion (paragraph 3, page 183) with supporting references." (A) I re-checked the 4th paragraph and there was no indication of criteria for matching. The authors had indeed talked about grouping the patients according to the bone age, in the 4th paragraph ("that were equally distributed into subgroups according to bone age and sex."), but that was not something about "matching" the patients. (B) Moreover, there was no mention of the chronological age in that 4th paragraph of the Methods section. However, this factor is used for correlating the two groups, according to the Results and Discussion. (C) Furthermore, in the same Methods sentence that had stated that bone age was used for grouping ("that were equally distributed into subgroups according to bone age and sex."), sex was mentioned as a grouping factor as well. So if that quoted sentence implies that bone age was a matching factor, should we consider sex as a matching criterion as well? The above-quoted sentence from the 4th paragraph of the Methods is actually the criteria for dividing the sample into subgroups. However, the authors are referring to it (in the authors’ reply) as something about matching. (D) Besides, I had noticed the comparisons and correlations of groups regarding bone ages, in the pages 182 and 183, but since those factors were not pre-defined as criteria for matching, those comparisons and the authors’ accompanying correlations could not indicate a matching between the groups to the reader.

      2. I appreciate the authors’ point #2. They kindly clarified the authors’ method.

      3. The authors have stated in the authors’ reply that they had tested both the whole sample and each subgroup regarding the normality... First that the authors’ article stated n > 50 for the normality test. However, the authors’ subgroups were much smaller than this. So n > 50 could not relate to subgroups of n = 19. Therefore, either the statement "n > 50" was incorrect, or they had not tested for normality in the subgroups. Moreover, normality should not be tested in the whole sample. It is completely incorrect. Besides, they did not state why they had used two different normality tests?

      4. There is nothing wrong with doing a pairwise comparison, and I did not say pairwise comparisons are bad, in my original letter. However doing a pairwise comparison without an ANOVA is statistical malpractice (when the ANOVA is necessary) and bad. It might have the following problems: (1) The absence of ANOVA disallows to assess the interactions. (2) Without an ANOVA design first, we do not know if any post hoc (or pairwise) comparisons are necessary or not, in the first place. If the ANOVA is non-significant, then performing the pairwise comparisons is simply moot (if we disregard the family-wise error introduced by the unnecessary statistical analyses). So this was why I was emphasizing on performing an ANOVA before doing the pairwise comparisons.

      5. The authors kindly stated " In our manuscript, "matched" means "constructing two groups whose data would be comparable with each other"." ... "The data of these groups are independent from each other and the presence of one group cannot alter the data of the other. " (A) Please note that "matched" has its own globally accepted definition that is to select groups with similarities in certain aspects. So using a personal definition for this word is not a healthy practice. (B) Moreover, the statement "constructing two groups whose data would be comparable with each other" implies (by the word "comparable") that there were actually similarities between the two groups, and thus some sort of matching had been actually performed. This again reveals that the two groups were not independent. (C) Furthermore, the Results and the Discussion (pages 182 and 183) clearly indicate that the two groups were correlated with each other according to the chronological and bone age: Page 182: "For both groups, the chronologic and bone ages of the subjects were correlated to each other" Page 183: "The control group, on the other hand, was created from skeletal Class I patients with no systemic diseases and whose chronologic and bone ages were correlated." (D) This evidence completely suffices to invalidate the use of ANY independent-samples test. Correlated groups CANNOT be independent. How "the presence of one group cannot alter the data of the other" when the authors had themselves selected the control group in a way that they were correlated to diabetic patients in terms of chronological and bone age? The control group was already altered in a way that it could be correlated to the diabetic patients.

      6. The authors have kindly re-stated that they had used the Bonferroni correction method. I had already seen the authors’ similar statement in the authors’ paper, but had not found any evidence supporting the authors’ statement. Please note that the Bonferroni correction is simply dividing the alpha by the number of pairwise comparisons in each family of tests. So we would expect to see alphas below 0.05 (for example 0.013 etc. depending on the number of pairwise comparisons). In that case, if the alpha had been corrected using the Bonferroni method to something like 0.008, and the P value had become P = 0.04, the P was still Non-Significant. However, throughout the text, and in the tables, only P values above the alpha = 0.05 had been considered as non-significant. This indicated that no Bonferroni had been used to adjust the alpha. (the alpha had not been adjusted in the first place).

      7. I much appreciate the authors’ correction and clarification.

      Many thanks for the readers' and authors' time.

      With kindest regards,

      Vahid Rakhshan


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    1. On 2016 Feb 22, Daniel Corcos commented:

      Actually, it is possible to estimate the relative risk associated to mammography by comparing the incidence of cancer in women with no exposure (whose age differ from women with exposure) to that of a BRCA carrier recent birth cohort (born after 1958) in figure 3 of Gabai-Kapara et al. It is also possible to use the data on interval breast cancer after negative mammography, showing that BC incidence is divided by more than three within two years following negative mammography (Bucchi et al., 2008). Both results suggest that figure 1 and 2 of Giannakeas et al. indicate a doubling of cancer incidence as a consequence of mammography. In other terms, these results suggest that a woman carrying a BRCA1 or BRCA2 mutation has a reasonable chance of not developing cancer if she has no mammography, and a very small chance to be spared if she has repeated mammography screening.

      References

      Gabai-Kapara et al; http://www.ncbi.nlm.nih.gov/pubmed/25192939

      Bucchi et al. http://www.ncbi.nlm.nih.gov/pubmed/18416953


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    2. On 2016 Feb 08, Daniel Corcos commented:

      Whether mammography screening increases the risk of breast cancer in women with DNA repair defect is an important question. In this paper, Giannakeas et al. found no difference in cancer incidence in women with previous mammography screening as compared to women with no prior irradiation. Negative mammography identify a population with a lower risk, since women with breast cancer are not part of the study. In the case of colon cancer, people with previous negative colonoscopy have a strongly reduced risk as compared to people with no previous colonoscopy (Brenner et al., 2011). Similarly it would be expected that women with negative mammography have a lower cancer incidence as compared to women with no previous mammography. Thus, Giannakeas et al. result suggests that mammography increases the risk of developing breast cancer in mutation carriers. http://www.ncbi.nlm.nih.gov/pubmed/21876077


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    1. On 2014 Aug 02, Hilda Bastian commented:

      While safer driving by adolescents is a critically important issue - and further research in this area is definitely needed, the authors' conclusions about the effects of this intervention are overly positive.

      The parent in these trials was overwhelmingly the mother (over 80%), mostly college-educated - and non-white families appear to have been under-represented. The participants responded to hearing about the trial rather than being actively recruited, and so were particularly highly motivated - and the trial couldn't reach its recruitment goal. Further, 16% of the intervention group were lost to follow-up at the primary outcome measurement point (compared with 6% in the control group).

      Even with this highly motivated group in a trial setting, of an intervention more intensive than a large-scale program could be (Ramirez M, 2013), and with outcomes based solely on the adolescents' reports, pre-specified primary outcomes (trial registration record) did not achieve statistical significance. While the authors fairly attribute this to low recruitment making the trial under-powered, it isn't very encouraging. As the authors point out, there's no strong effect apparent here.

      Presenting the adolescents' self-reported Risky Driving Score results as risk reduction percentages in the abstract risks giving people an exaggerated impression of effectiveness. The range of possible score isn't very wide, so even a small difference can be a substantial percentage. It would have been good if more details about the score were provided, given that it's a primary outcome measure and it was a trial-specific adaptation of an existing score.

      It's great to see this trial published, even though it didn't meet its goals. But I don't agree with the authors' conclusion that statistical significance levels should be dropped low, in effect, because proven interventions are needed. The interventions that people would use need to make a real difference. As the authors point out, there is evidence that parents can make a difference to their adolescents' behaviors - to their list, I'd add influencing smoking (Thomas RE, 2007). But parents need to know where they could make the best effort, given the other options like Parent-Teen Driving Agreements (Zakrajsek JS, 2013) - or discouraging getting a license early (Ian R, 2001).

      The authors indicate that future research will integrate more objective data, which presumably refers to the unreported data from 2010 for driving citations and crashes in this trial. That will be vital to put this self-reported data on surrogate outcomes in perspective. Access for others to the intervention materials may be important for others in the field (Glasziou P, 2010).


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    1. On 2014 Aug 27, Ryan Radecki commented:

      Post-publication commentary:

      "Nitric Oxide Supplies No Miracles in Sepsis"

      An interesting context to end-organ dysfunction in sepsis stems from microcirculatory dysfunction, secondary to endothelial activation and vascular disruption as part of the inflammatory cascade. Even though abnormal vasoconstriction in sepsis may be pharmacologically ameliorated, microcirculatory perfusion remains impaired....

      http://www.emlitofnote.com/2014/08/nitric-oxide-supplies-no-miracles-in.html


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    1. On 2014 Sep 15, Amanda Capes-Davis commented:

      This study uses HEp-2 to investigate the role of CUGBP1 in laryngeal cancer. Please be aware that HEp-2 is known to be cross-contaminated with HeLa, which is from cervical cancer. These results do not relate to laryngeal cancer.

      Laboratories can test their cell line stocks for cross-contamination using a consensus method such as short tandem repeat (STR) profiling. For a list of known cross-contaminated cell lines, see http://iclac.org/databases/cross-contaminations/.


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    1. On 2017 Jun 15, Feng Zhang commented:

      A number of researchers have inquired about the presence of duplicate sgRNAs (same sgRNA for more than one gene) in the GeCKOv2 library (Sanjana et al., Nature Methods 2014) and non-specific sgRNAs that have additional exact matches in the genome. We would like to further clarify the design considerations for GeCKOv2 (Supplementary Methods, Sanjana et al., Nature Methods 2014).

      For the GeCKOv2 libraries we decided to take the “best” sgRNA (i.e. with the fewest off-targets) we could find for a given gene, even if in some cases our “best” sgRNA had more than one targeting location in the genome. This was done to sample as many targets as possible and minimize false negatives, since false positives that are due to an sgRNA with more than one target or off target effects can be easily eliminated in post-screen validation experiments or through a gene-based analysis that selects hits based on the consistent effect of multiple unique sgRNAs. Regardless, each candidate obtained through a GeCKO screen needs to be validated through rigorous experimentation, including testing using new guides targeting each screen hit.

      A special example are gene families with high homology, in such cases our algorithm was not able to find a unique sgRNA targeting a constitutive exon. The approach that we took was to leave in these sgRNAs to give users the greatest range of options (and potential targets) during post-screen validation experiments. For example, in the human GeCKOv2 library, there are 5,664 non-specific sgRNAs. This works out to be ~4% of all guides in the library. Those redundant sgRNAs can always be removed computationally, following a screen, to simplify data analysis. (A table of these sgRNAs and genes targeted with multiple non-specific sgRNAs is available here: [link]). In contrast, GeCKOv1 did not include as many non-specific guides and consequently only targets a smaller number of genes.

      To clarify this and help users in their analysis we previously provided the GeCKOv2 sgRNA database with information about the number of off-target target hits (e.g. [link]). We also have provided an additional sgRNA index for both human and mouse GeCKOv2 libraries that lists only unique sgRNAs such that when multiple genes are targeted all of those are listed under gene_id [link].

      The GeCKOv2 libraries have already been successfully used by many groups to generate a number of interesting biological findings (e.g. Golden et al., Nature, 2017, Erb et al., Nature, 2017; Xu et al., PNAS, 2017; Jain et al., Science, 2016; Marcaeu et al., Nature, 2016; Zhang et al., Nature, 2016; Meitinger et al., JCB, 2016; Wallace et al., PLoS One, 2016; Parnas et al., Cell, 2015; Chen et al., Cell, 2015). In addition to GeCKOv2, there are a number of alternative libraries (e.g. Wang et al., Science, 2015; Doench et al., Nat. Biotechnol., 2016; Hart et al., Cell, 2015), including libraries that were designed to avoid duplicate sgRNAs by targeting fewer genes. A list of different libraries is available on Addgene’s pooled CRISPR libraries page: [link].

      We would like to specifically thank Joey Riepsaame and Timokratis Karamitros for recently bringing this issue to our attention. We also thank the GeCKO users who contacted us through the CRISPR Genome Engineering online forum and by email for additional helpful discussions.

      Neville E. Sanjana (nsanjana at nygenome.org)

      Ophir Shalem (shalemo at email.chop.edu)

      Joey Riepsaame (joey.riepsaame at path.ox.ac.uk)

      Timokratis Karamitros (timokratis.karamitros at zoo.ox.ac.uk)

      Feng Zhang (zhang at broadinstitute.org)

      References Cited

      Chen, S., Sanjana, N.E., Zheng, K., Shalem, O., Lee, K., Shi, X., Scott, D.A., Song, J., Pan, J.Q., Weissleder, R., et al. (2015). Genome-wide CRISPR screen in a mouse model of tumor growth and metastasis. Cell 160, 1246–1260.

      Doench, J.G., Fusi, N., Sullender, M., Hegde, M., Vaimberg, E.W., Donovan, K.F., Smith, I., Tothova, Z., Wilen, C., Orchard, R., et al. (2016). Optimized sgRNA design to maximize activity and minimize off-target effects of CRISPR-Cas9. Nat. Biotechnol. 34, 184–191.

      Erb, M.A., Scott, T.G., Li, B.E., Xie, H., Paulk, J., Seo, H.-S., Souza, A., Roberts, J.M., Dastjerdi, S., Buckley, D.L., et al. (2017). Transcription control by the ENL YEATS domain in acute leukaemia. Nature 543, 270–274.

      Golden, R.J., Chen, B., Li, T., Braun, J., Manjunath, H., Chen, X., Wu, J., Schmid, V., Chang, T.-C., Kopp, F., et al. (2017). An Argonaute phosphorylation cycle promotes microRNA-mediated silencing. Nature 542, 197–202.

      Hart, T., Tong, A., Chan, K., van Leeuwen, J., Seetharaman, A., Aregger, M., Chandrashekhar, M., Hustedt, N., Seth, S., Noonan, A., et al. (2017). Evaluation and Design of Genome-wide CRISPR/Cas9 Knockout Screens. bioRxiv.

      Jain, I.H., Zazzeron, L., Goli, R., Alexa, K., Schatzman-Bone, S., Dhillon, H., Goldberger, O., Peng, J., Shalem, O., Sanjana, N.E., et al. (2016). Hypoxia as a therapy for mitochondrial disease. Science 352, 54–61.

      Marceau, C.D., Puschnik, A.S., Majzoub, K., Ooi, Y.S., Brewer, S.M., Fuchs, G., Swaminathan, K., Mata, M.A., Elias, J.E., Sarnow, P., et al. (2016). Genetic dissection of Flaviviridae host factors through genome-scale CRISPR screens. Nature 535, 159–163.

      Meitinger, F., Anzola, J.V., Kaulich, M., Richardson, A., Stender, J.D., Benner, C., Glass, C.K., Dowdy, S.F., Desai, A., Shiau, A.K., et al. (2016). 53BP1 and USP28 mediate p53 activation and G1 arrest after centrosome loss or extended mitotic duration. J. Cell Biol. 214, 155–166.

      Parnas, O., Jovanovic, M., Eisenhaure, T.M., Herbst, R.H., Dixit, A., Ye, C.J., Przybylski, D., Platt, R.J., Tirosh, I., Sanjana, N.E., et al. (2015). A Genome-wide CRISPR Screen in Primary Immune Cells to Dissect Regulatory Networks. Cell 162, 675–686.

      Sanjana, N.E., Shalem, O., and Zhang, F. (2014). Improved vectors and genome-wide libraries for CRISPR screening. Nat. Methods 11, 783–784.

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    1. On 2014 Sep 30, Ryan Radecki commented:

      Post-publication commentary:

      "For tPA, Is Delusion the Standard of Care?"

      Yet again, the tPA apologists dip into their bag of registry data in an attempt to defend tPA – and end up contradicting themselves.

      In 2009, neurologists in India published a retrospective case series examining the outcomes following tPA at their institution. Specifically, they divided up the cases between those with arterial occlusion present on CT angiogram of the cerebral vessels, and those with no demonstrated arterial occlusion. For patients with demonstrated occlusion, there were significant differences in early NIHSS improvement favoring tPA, but no long term mRS improvements. Conversely, there were 119 without occlusion present – and the early NIHSS improvement and late mRS improvement outcomes were similar. There were, however, substantial baseline differences between those receiving tPA and those who did not – and retrospective studies are confounded by many biases – but there was at least a suggestion that some stroke subtypes might not benefit from tPA....

      http://www.emlitofnote.com/2014/09/for-tpa-is-delusion-standard-of-care.html


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    1. On 2014 Aug 07, Jim Woodgett commented:

      Very thorough study on the effects of complete inactivation of GSK-3 (both isoforms) on radial migration of neurons and on dendritic morphology. The results here don't agree with previously reported role of Lkb1/STK11 on negative regulation of GSK-3 (via serine 21/9 phosphorylation). This is difficult to reconcile but may reflect the fact that such phosphorylation only partially inhibits GSK-3 (~50%) and that all compartments of GSK-3 are affected by genetic knockout verses only some that are sensitive to regulation by phosphorylation. The authors also show the effects of GSK-3 inactivation are not mediated by Wnt signalling which is typically the dominant pathway that is de-inhibited under this context and in, for example, nestin-Cre/GSK-3KO animals is one of the (but not only) primary drivers of neuronal progenitor proliferation. Together, the data indicate that the effects of these kinases on radial migration are largely insulated from the many other effects on cellular functions.

      As an aside, this paper makes great use of the embedded media of eLife although there is no direct link to the eLife manuscript from PubMed yet (http://elifesciences.org/content/3/e02663).


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    1. On 2014 Aug 04, Ryan Radecki commented:

      Post-publication commentary:

      "The tPA Cochrane Review Takes Us For Fools"

      It’s been 5 years since the last Cochrane Review synthesizing the evidence regarding tPA in acute ischemic stroke. Clearly, given such a time span, in an area of active clinical controversy, a great deal of new, important, randomized evidence has been generated!

      Or, sadly, the only new evidence available to inform practice is IST-3 – a study failing to demonstrate benefit, despite its pro-tPA flaws and biases. So, it ought not be a very exciting update, considering the 2009 version included 26 trials, and the 2014 update now includes only 27 trials. Their summary conclusion, with only additional evidence of regression to the mean, ought remain essentially the same, or even less optimistic, right?

      http://www.emlitofnote.com/2014/08/the-tpa-cochrane-review-takes-us-for.html


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    1. On 2015 Sep 01, E Schuman commented:

      Critical Flaws in Ainsley et al., “Functionally diverse dendritic mRNAs rapidly associate with ribosomes following a novel experience”, DOI: 10.1038/ncomms5510

      Submitted by: Georgi Tushev and Erin Schuman (Max Planck Institute for Brain Research, Frankfurt am Main, Germany) and Wei Chen (Max Delbruck Center, Berlin, Germany).

      http://brain.mpg.de/uploads/media/Ainsley_Rebuttal_01Sep2015.pdf

      In this paper the authors conduct a fear conditioning experiment (“novel-experience”), isolate ribosome-bound mRNA from the dendrites of mouse hippocampal neurons, conduct deep RNA sequencing and then use a machine-learning classification scheme to identify the mRNAs present in dendrites following learning. Upon close reading and re-analysis of the published data we found substantive flaws including the absence of an analyzed control group, low sequencing depth, high variability between replicas, and poor classification of genes. We discuss these issues in greater detail below.

      Absence of a completely analyzed control group. In biological experiments, the assessment of statistically significant differences between groups (e.g. control and experimental groups, drawn from a normal distribution) uses information about the variability in each group in order to estimate the likelihood that between-group differences occurred by chance. Ainsley et al. attempted to compare ribosome-bound RNA from control ("home-cage") and "novel- experience" animals, ignoring their own observations (see Ainsley et al Fig. S2) that the variation among the biological replicates within each group is as large as the variation between the two conditions. Moreover, the authors themselves indicate that their machine learning classifier was unable to classify their home-cage data and as such, do not analyze the “control” group. Thus, without further statistical assessment, it is not appropriate to make general statements about the translational regulation induced upon “novel experience” (fear-conditioning) because there is no control group data analysis to compare it to.

      Low sequencing depth compromises reproducibility and leads to high replicate variability. In the analysis of deep-sequencing datasets, one maps the sequenced reads to a reference genome to identify the gene from which the transcript originated. With current RNA extraction, library preparation and sequencing techniques, the generally accepted lower-bound of “mappable” reads for an analyzable data set is around 75-80% (Sims et al.). In Ainsley et al. the average fraction of reads which yield useful information in all samples is low, (47.4%) leading to low sequencing depth; the analysis reported in Ainsley et al and our own re-analysis of the data agree on this (see our Figure 1A and B). Indeed, the fraction of mapped reads in the immunoprecipitated (IP) fraction (“ribosome-bound”) (which the authors focus their analysis on) is even lower than all other groups (< 40%) (our Figure 1A and B, http://brain.mpg.de/uploads/media/Ainsley_Rebuttal_01Sep2015.pdf). For comparison, a very similar recent study (using the same technique with a brain sample) showed a much higher fraction of mapped reads (Hupe et al., 2014). Although the authors report the use of a ribosomal RNA-depleted sample, (the Ovation RNA-Seq kit used for RNA amplification is not supposed to bind ribosomal RNA), a substantial fraction of their reads actually map to ribosomal RNA (Figure 1B). As a consequence, the genes detected in the sequencing replicates show very low gene overlap and the estimated RNA abundance is also poorly correlated (~ range 0.32 -0.72), again particularly in the IP fraction which is the focus of Ainsley et al.’s analysis (range 0.32-0.42) (our Figure 1C and D). For comparison, Hupe et al reported high replicability for their brain translatome data with all correlation values in excess of 0.98 (Hupe et al., 2014). Incorrect gene feature representation: Inclusion of non-coding RNA reads as mRNA reads. In the analysis of their data, Ainsley et al. map the sequencing reads to different domains of a gene e.g. reads aligned to the 5’UTR (untranslated region), coding sequence (CDS) and 3’UTR. In Figure 2a they report, surprisingly, that in different groups, between 22-80% of the reads map to the 3’UTR. Their annotation is in stark contrast to other published studies where, using similar techniques, an even distribution of reads throughout the gene body is typically observed (e.g. Hupe et al., 2014). In our Figure 2A (http://brain.mpg.de/uploads/media/Ainsley_Rebuttal_01Sep2015.pdf), using the raw published data, Ainsley et al.’s reads are independently mapped and the observed fractional annotation fails to confirm Ainsley’s report (our Figure 2A; compare to original Figure 2A in Ainsley et al). Indeed, the only way one can replicate their skewed (huge contribution of the 3’UTR reads) distribution is to include reads that map to non-coding RNA loci and erroneously assign them to the 3’UTR (our Figure 2B). The correct annotation of read position is important because Ainsley et al. go on to use these read positions in genes to train a classifier to identify mRNAs as pyramidal (+pyr) or non-pyramidal (-pyr).

      Flawed input, flawed design, and flawed output of a gene classifier. Ainsley et al used a training gene set to train a classifier to recognize transcripts as those transcripts arising from dendrites of pyramidal neurons (+pyr) or other cells in the neuropil (-pyr). The training set comprised 74 (+pyr) and 124 (-pyr) genes that the authors compiled by their own visual inspection of the Allen Brain Atlas. Unfortunately a significant fraction of these genes are completely absent from the author’s own analyzed dataset (40/74 +pyr genes and 38/123 -pyr genes missing, Supplementary Data 2 in Ainsley et al.). Furthermore, the authors propose, without any data to substantiate it, that reads from +pyr genes should be CDS-enriched and 3’UTR- de-enriched in their IP (“ribosome-bound”) fraction, relative to the supernatant fraction. Recreating the clustering procedure of Ainsley et al with adequate accuracy one observes that the genes are separated only by expression dominance in the IP fraction, independent of CDS or 3’UTR enrichment (Figure 2C). This graph reveals absolutely no clustering of genes, as would be expected if the author’s original formulation/idea were correct. Furthermore, we attempted to recreate the clustering using different pairs of biological replicates provided in the Ainsley et al study. The majority of replicates samples fail to successfully cluster the data with the same precision and accuracy as expected (clustering measures <0.5, Figure 2D). The above result is not surprising given the overall poor data quality, depth and expression correlation. This offers one explanation for why the authors were unable to classify their home-cage “control” dataset (Ainsley et al. page 4). In addition, we compiled a list of 139 in situ hybridization-verified dendritic mRNAs from several sources (Lein et al., Cajigas et al and references therein) and compared it to the “+pyr“ and “–pyr“ classified set suggested by Ainsley et al. (Figure 2E and 2F, Table 1 http://brain.mpg.de/uploads/media/Ainsley_Rebuttal_01Sep2015.pdf). We found that less than 35% of the dendritically-verified transcripts (from the above lists) were included in the Ainsley et al., (+pyr) list, the majority were in fact listed on the -pyr list. Even 16 genes that the Allen Brain Atlas team indicated as “dendritic” (e.g. Lein et al.,) were mis-classified by Ainsley et al. as (–pyr) (Table 1). In summary, the study of Ainsley et al., is flawed at many levels, including experimental design, poor data quality and incorrect analyses, invalidating many, if not all, of the conclusions of the authors.


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    1. On 2016 Apr 10, Lydia Maniatis commented:

      For the reasons described below, this introductory sentence has no content: "Noise can be used to characterize visual processing in noiseless conditions. For instance, contrast detection threshold in absence of noise is limited by both internal noise and the ability of detecting the signal embedded in noise, namely, calculation efficiency, which is inversely proportional to the smallest signal-to-(internal) noise ratio required to detect the signal."

      The stimulus consists of photons hitting the retina. Is this the "signal" according to these authors? No. The "signal" is a product of perceptual organisation to which the stimulus may give rise. This signal (e.g. a letter of the alphabet) has been designated a priori by the authors. If the stimulus is created by laying out a perceptible letter shape, and then adding dots overlying it, the additional dots will be called the "noise" even though they are a perfectly good "signal." The dots, called "external noise" will be supposed to represent "noise" and to constitute some kind of parallel to supposed "internal noise" that is supposed to mediate the percept (though to my knowledge no empirical tests of this assumption have been performed). The arbitrariness of the signal/noise dichotomy may be appreciated if we imagine that the letters themselves are composed of the same type of dots? Would we say the "signal" is composed of "noise?"

      What if, instead of dots, the "added noise" consisted of lines?

      Unless we specify that "noise" will always be defined as a specific structure, e.g. pixels of x visual angle and y luminance structure, then the effect of the arbitrarily defined "noise" on the arbitrarily designated "signal" will always depend on the physical characteristics of both and how they interact to influence the perceptual organisation of the stimulus. As has been demonstrated many times (e.g. by Gottschald, Kanizsa, Wertheimer), in some "noisy" conditions the "signal" may not be detectable at all, even if its contrast is high.

      Thus, referring to "noise" and "signal" in the abstract, without reference to structure, is meaningless. Therefore, the introductory sentence quoted above has no content.

      QED.


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    1. On 2014 Aug 06, Samir Ounzain commented:

      Thank you Dr Matkovich for clarifying these points, both myself and readers will appreciate this quick and comprehensive response. I understand that the review process can lead to absence of specific pieces of literature, especially those published in a comparable time frame. However typically in the process of revision it is important to cite even recently pubished work and discuss if highly relevant to your study. Many pieces of work are submitted months if not years before final acceptance but we all have a responsibility to correctly cite and discuss highly relevant recent work during any revisions. I would also like to clarify that citations 4 and 26 by the Hermann group and ourselves are not the most relevant in this context. Citation 24 is a review article and reference 4 describes Fendrr and not the recent more global characterisation of embryonic cardiac lncRNAs by the Herrmann group (for benefit of community these citations are in original post). For the benefit of everybody in this exciting new and emerging field it is of importance that all relevant and recent studies are included and discussed. Hopefully our discussion here as raised these points to the benefit of the field. I congratulate you on your important piece work, and especially your delineation of putative –cis control of proximal coding genes via lncRNAs characterised in your study. I think –cis control, especially for those lncRNAs templated by cardiac enhancers will emerge as an important regulatory function for the global enhancer reprogramming that underpins the re-activation of the fetal gene program and subsequent pathological remodelling. Your work provides further signficant evidence for the potential importance of lncRNAs in the developing and remodelling heart. I look forward to further studies from your Laboratory and the community. Functional and phenotypic characterisation of these exciting new cardiac enriched molecules is now of importance for all in the community.


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    2. On 2014 Aug 05, Scot Matkovich commented:

      I'm pleased that our recent publication has already attracted interested readers. With regard to the references we cited and the publication date of other literature in the field, we first submitted this paper to PNAS in November 2013; as is the trend at a lot of journals, the 'submission date' on the final paper is actually the receipt date of the most recent major revision (June 2014). We had already cited papers from the Herrmann and Pedrazzini groups as references 4 and 26. I would suggest that neither the peer review process nor the authors have been delinquent in failing to cite extremely recent literature, whose e-publication dates were largely coincident with the preparation of our revised manuscript.

      I would like to clarify one misrepresentation of our study made by Dr Ounzain. We did not attempt to identify 'novel' murine lncRNAs in the developing and adult heart, but rather sought to bring a degree of curation and refinement to the characterization of cardiac lncRNAs by focusing on a limited set of lncRNAs with strong evidence for existence as separate entities. We tried to avoid including database entries which may be spuriously annotated fragments of other RNAs, as indicated in our Supplemental Methods. Using this carefully selected set of lncRNAs, we evaluated the extent to which they were regulated during growth of the embryonic heart or pressure overload-induced hypertrophy. I feel it is likely that a similar disparity of lncRNA regulation between these two growth states will be found no matter how many lncRNAs are included in such a comparison.

      Nonetheless, I would like to thank Dr Ounzain for pointing out that his recent study provides a thorough catalog of 'known' and 'novel' murine cardiac lncRNAs as determined by ab initio reconstruction of paired-end RNAseq transcripts. As annotation improves with time and a common nomenclature for lncRNAs is decided, both of our raw sequencing read datasets should prove fruitful for others to mine and to investigate cardiac lncRNA regulation. The mechanistic studies we performed on reciprocally regulated lncRNAs and adjacent coding mRNAs should provide a useful framework for evaluating the extent to which other lncRNAs may regulate local transcription.


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