Mycobacterium paratuberculosis has been isolated from tissue taken from patients with Crohn's disease and has been implicated in the etiology of this disease. On culture, the organisms appear initially as cell wall-deficient, spheroplast-like forms that are difficult to identify by conventional techniques. Here we examine 30 unidentified cultures by the polymerase chain reaction using primers specific for M.
View Article and Find Full Text PDFThe nucleotide sequence of a swine vesicular disease virus (SVDV) strain that is pathogenic for pigs has been determined and compared with that of a non-pathogenic strain of SVDV, as well as a number of other enteroviruses. It shows only 98 base changes in comparison with a non-pathogenic strain of SVDV (Inoue et al., 1989, J.
View Article and Find Full Text PDFThe role of melanocyte stimulating hormone (MSH) as a mediator of the melanogenic response to ultraviolet radiation (UVR) was examined in C57 BL/6 mice. While exposure to UVR (250-300 nm) for 7, 14 and 27 days increased tyrosinase activity in epidermal melanocytes of the ear MSH had no effect and failed to alter the response to UVR. Plasma alpha-MSH concentrations were unchanged following UVR.
View Article and Find Full Text PDFIn this study, the effect of alpha-MSH on tyrosinase activity was compared in epidermal and hair follicular melanocytes of mice. It had no effect on epidermal tyrosinase activity in dorsal skin from neonatal non-agouti black mice (C57BL/6J) in both in-vivo and in-vitro experiments. Theophylline and 8-bromocyclic (c)AMP were similarly without effect in in-vitro experiments.
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