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The effect of neurotensin on submaximally-stimulated hepatobiliary and pancreatic secretion was studied in 6 healthy subjects. An intravenous infusion of neurotensin 1.4 ± 0.3 pmol/kg/min, designed to reproduce plasma neurotensin immunoreactivity levels within the physiological range, produced a significant increase in pancreatic bicarbonate output. Plasma concentrations of pancreatic polypeptide rose by 83 ± 16 pmol/l and were associated with a small reduction in trypsin, but no significant change in bilirubin outputs. 相似文献
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AB Zarafi AM Emechebe AD Akpa O Alabi 《Archives Of Phytopathology And Plant Protection》2013,46(4):261-268
Pearl millet downy mildew (DM) incidence, severity and yield losses of two pearl millet varieties (local and improved) due to the disease were determined in the field. Significant differences in the disease incidence and severity were recorded in the plots sown with metalaxyl-treated seeds and those sown with non-treated seeds, indicating the efficacy of the fungicide on the fungus. Yield losses due to non-treatment of seeds with metalaxyl was 40.88 and 45.39% in a local variety and 43.00 and 18.60% in an improved variety in the 2000 and 2001 cropping seasons respectively. Significant differences between plots sown with metalaxyl-treated and those sown with non-treated seeds were obtained for other yield components such as 1000-grains weight, panicle length and weight. 相似文献
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Marchal LM van de Laar AM Goetheer E Schimmelpennink EB Bergsma J Beeftink HH Tramper J 《Biotechnology and bioengineering》1999,63(3):344-355
The hydrolysis of starch to low-molecular-weight products (normally characterised by their dextrose equivalent (DE), which is directly related to the number-average molecular mass) was studied at different temperatures. Amylopectin potato starch, lacking amylose, was selected because of its low tendency towards retrogradation at lower temperatures. Bacillus licheniformis alpha-amylase was added to 10% [w/w] gelatinised starch solutions. The hydrolysis experiments were done at 50, 70, and 90 degrees C. Samples were taken at defined DE values and these were analysed with respect to their saccharide composition. At the same DE the oligosaccharide composition depended on the hydrolysis temperature. This implies that at the same net number of bonds hydrolysed by the enzyme, the saccharide composition was different. The hydrolysis temperature also influenced the initial overall molecular-weight distribution. Higher temperatures led to a more homogenous molecular weight distribution. Similar effects were observed for alpha-amylases from other microbial sources such as Bacillus amyloliquefaciens and Bacillus stearothermophilus. Varying the pH (5.1, 6.2, and 7.6) at 70 degrees C did not significantly influence the saccharide composition obtained during B. licheniformis alpha-amylase hydrolysis. The underlying mechanisms for B. licheniformis alpha-amylase were studied using pure linear oligosaccharides, ranging from maltotriose to maltoheptaose as substrates. Activation energies for the hydrolysis of individual oligosaccharides were calculated from Arrhenius plots at 60, 70, 80, and 90 degrees C. Oligosaccharides with a degree of polymerisation exceeding that of the substrate could be detected. The contribution of these oligosaccharides increased as the degree of polymerisation of the substrate decreased and the temperature of hydrolysis increased. The product specificity decreased with increasing temperature of hydrolysis, which led to a more equal distribution between the possible products formed. Calculations with the subsite map as determined for the closely related alpha-amylase from B. amyloliquefaciens reconfirmed this finding of a decreased substrate specificity with increased temperature of hydrolysis. Copyright 1999 John Wiley & Sons, Inc. 相似文献
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A screen for identifying genes interacting with armadillo, the Drosophila homolog of beta-catenin 总被引:29,自引:0,他引:29
Applications of quantitative genetics and conservation genetics often require measures of pairwise relationships between individuals, which, in the absence of known pedigree structure, can be estimated only by use of molecular markers. Here we introduce methods for the joint estimation of the two-gene and four-gene coefficients of relationship from data on codominant molecular markers in randomly mating populations. In a comparison with other published estimators of pairwise relatedness, we find these new "regression" estimators to be computationally simpler and to yield similar or lower sampling variances, particularly when many loci are used or when loci are hypervariable. Two examples are given in which the new estimators are applied to natural populations, one that reveals isolation-by-distance in an annual plant and the other that suggests a genetic basis for a coat color polymorphism in bears. 相似文献
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Buhot C Chenal A Sanson A Pouvelle-Moratille S Gelb MH Ménez A Gillet D Maillère B 《Protein science : a publication of the Protein Society》2004,13(11):2970-2978
We have engineered a recombinant form of the major bee venom allergen (Api m 1) with the final goal of reducing its IgE reactivity. This molecule (Api mut) contains 24 mutations and one deletion of 10 amino acids. The successive introduction of these sequence modifications led to a progressive loss of specific IgE and IgG reactivity and did not reveal any immunodominant epitopes. However, Api mut exhibited a clear loss of reactivity for Api m 1-specific IgE and IgG. Injection of Api mut into mice induced specific antibody production. This humoral response was as high as that induced by the Api m 1 but the cross-reactivity of the antibodies was weak. As inferred by far UV circular dichroism, this mutant was correctly folded. However, near UV circular dichroism and denaturation curves of Api mut showed that it exhibits a dynamic tertiary structure and that it is a highly flexible molecule. Finally, as all the sequence modifications have been introduced outside the human and murine T cell epitope regions, we investigated its T cell properties in mice. We showed that Api mut-specific T lymphocytes induced in vivo were stimulated in vitro by both proteins. These data provide new insights in the design of hypoallergenic molecules. 相似文献