Studies on Parameters Influencing the Performance of Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) in Detecting Prunus Necrotic Ringpot Virus (PNRSV)

In order to have a more detailed understanding of the various factors influencing a reverse transcriptase polymerase chain reaction (RT-PCR), a number of important parameters such as Mg+2, primer, enzyme concentration and others were optimized for the detection of Prunus necrotic ringspot virus (PNRSV). Using a PNRSV isolate with a pair of primers, complementary DNA of viral genome as template, and an appropriate enzyme together with magnesium chloride, the following optimal conditions were identified: primer concentration between 0.2 and 0.0002 pmol µl-1 and 0.06–2 units µl-1 for Taq DNA polymerase enzyme for a 50 µl reaction volume when other parameters were optimum; magnesium chloride concentration less than 2.5 mM; dNTP concentration between 1 and 10 mM. The optimum cDNA amount should be ~360 ng for a 50 µl reaction mixture. When these optimized concentrations and/or values of the main PCR parameters were brought together for a new RT-PCR, a clear and a reliable PNRSV detection having no background was performed from both growth-chamber and field-grown PNRSV-infected plants

Fiber enriched diets and radiation induced injury of the gut

WOS: 000180640900009The aim of this study was to evaluate the effect of fiber-enriched defined formula diets (DFDs) on radiation-induced enteropathy. Forty-five male Sprague-Dawley rats were assigned randomly after abdominal irradiation to one of three groups (15 in each group): a fiber-free DFD group, a non-soluble fiber-enriched DFD group, and a soluble fiber-enriched DFD group. They kept their diets respectively for seven days. On day eight, the mesenteric lymph nodes were harvested for bacterial translocation, and segments of jejenum and colon were sampled for microscopic examination. The rats in the fiber-enriched DFD groups lost significantly less body weight than the rats in the fiber-free DFD group. The intestinal structure was the worst in the fiber-free DFD group, intermediate in the soluble fiber-enriched DFD group, and the best in the non-soluble fiber-enriched DFD group with significantly higher measures of villous height and jejunal mucosal thickness. These findings suggest that fiber-enriched DFD may effectively protect intestinal structure against radiation-induced damage by improving mucosal integrity. (C) 2003 Elsevier Science Inc. All rights reserved