On 2013 Oct 29, DAVID SANDERS commented:

From Lynch CM, 1992 "Nabel et al. have reported direct gene transfer into quiescent cells in all layers of the arterial wall of Yucatan minipigs by both retroviral infection and by lipofection using B-gal as the marker gene. High levels of background B-gal activity resulting in false positives were not reported. However, given that blue staining of vessels exposed to virus was the only criteria used to document gene transfer, and given the variable background staining that we and others Lim CS, 1991 observe, these results must be confirmed by additional molecular analysis to verify the presence of the vector. If gene transfer did occur under these conditions,we predict that the efficiency of gene transfer must have been very low..." See also Flugelman MY, 1992.

On 2013 Oct 29, DAVID SANDERS commented:

From Lynch CM, 1992 "Nabel et al. have reported direct gene transfer into quiescent cells in all layers of the arterial wall of Yucatan minipigs by both retroviral infection and by lipofection using B-gal as the marker gene. High levels of background B-gal activity resulting in false positives were not reported. However, given that blue staining of vessels exposed to virus was the only criteria used to document gene transfer, and given the variable background staining that we and others Lim CS, 1991 observe, these results must be confirmed by additional molecular analysis to verify the presence of the vector. If gene transfer did occur under these conditions,we predict that the efficiency of gene transfer must have been very low..." See also Flugelman MY, 1992.