Insulin and glucose regulation.

Abnormally high or low blood glucose and insulin concentrations after standardized glucose tolerance tests can reflect disorders such as pituitary dysfunction, polysaccharide storage myopathies, and other clinical disorders. Glucose and insulin responses, however, are modified by the diet to which the animal has adapted, time since it was last fed, and what it was fed. Body fat (obesity), fitness level, physiologic status, and stress also alter glucose and insulin metabolism. Therefore, it is important to consider these factors when evaluating glucose and insulin tests, especially if only one sample it taken. This article describes the factors affecting glucose and insulin metabolism in horses and how they might influence the interpretation of standardized tests of glucose tolerance.     

蛋白质营养的未来是肽营养

优化蛋白质营养不再仅仅是对日粮进行大致的氨基酸平衡。蛋白质的形式对猪的健康和生长会产生长远的影响。　　蛋白质摄入量是生长猪营养中的一个基本要素。要提高瘦肉生长率,就需要平衡良好的氨基酸以供蛋白质合成之用,这些氨基酸需要以一定的形式通过日粮来提供。现在能够对饲料进行精确的分析,并且有来源可靠的合成氨基酸,已经为猪的蛋白质营养提供了坚实的基础。然而,有时候这会导致过量氮的排泄,因为并非提供的所有的蛋白质都会被猪吸收。过量氮的排出,不但会造成浪费,而且还会对环境造成污染。近年来,新的证据表明,单独提供氨基酸可能…     

The in vivo sensitivity of ATPases to DDT,DDE, and physical immobilization in American cockroaches

American cockroaches injected with sublethal doses of DDT (0.75 μg/roach) at 5-day intervals showed a 40% reduction in oligomycin-sensitive Mg²⁺ATPase from muscle homogenates, and a 23% reduction of Na⁺-K⁺ATPase from nerve cords. Thus, the maximum effect measured occurred with the same enzyme and tissue as determined from in vitro studies. The metabolite, DDE, used at 15 μg per roach, gave no significant change in activity of the ATPase system following injection. In contrast, high single doses of DDT (7.5 μg/roach) and 100 μg DDE and dicofol per roach caused over 30% increase in oligomycin-sensitive Mg²⁺ATPase of muscle and a 10–15% increase in Na⁺-K⁺ATPase of nerve cords measured 24 and 48 hr later. While a similar response was observed for Mg²⁺ATPase activities in cockroaches that were immobilized, the increase in enzyme activities were much greater than that caused by the pesticides.     

Pharmacokinetics of carfentanil and naltrexone in domestic goats (Capra hircus).

Using a crossover study design, the pharmacokinetics of carfentanil and naltrexone after i.v., i.m., and s.c. administration were determined in eight domestic goats (Capra hircus). Serial blood samples were taken up to 120 hr after carfentanil administration, and the plasma drug concentrations were determined using liquid chromatography and mass spectroscopy. All goats were immobilized with 40 microg/kg carfentanil i.m., although the resulting neurologic effects varied considerably. Plasma profiles showed rapid carfentanil absorption and a simple biphasic decline for 12-48 hr. Naltrexone given at 100 mg naltrexone/mg carfentanil 30 min after carfentanil administration produced rapid reversal of immobilization after all routes of administration. Variable fluctuations in the naltrexone plasma concentrations during the first 2.5-3.5 hr were observed, followed by a more consistent biphasic decline. The time to standing was significantly shorter after i.v. compared with s.c. naltrexone, although the time difference (1 min) had little clinical relevance. No statistically significant differences between the naltrexone pharmacokinetic parameters measured for the three routes of naltrexone administration were identified, although the recoveries after i.m. administration were, subjectively, the smoothest. The carfentanil half-life did not differ significantly in the goats given naltrexone by different routes. Although it is currently recommended that the naltrexone dose be divided into s.c. and i.v. portions, this practice does not appear to offer any benefit.     

Analysis of a Secreted Aspartic Peptidase Disruption Mutant of Glomerella cingulata

Peptidases have been implicated in the pathogenicity of fungi that cause disease in plants. Expression of the secreted aspartic peptidase gene (gcsap), of a Glomerella cingulata isolate pathogenic on apples, is induced during appressorium formation. To determine whether the secreted aspartic peptidase (GcSAP) is essential to pathogenicity, gcsap was disrupted using a vector containing a 637 bp fragment of genomic DNA that encodes the sequence spanning the two active site aspartic acid (Asp) residues. To ensure that the truncated gcsap gene products could not have residual peptidase activity the codons for the active site residues Asp¹¹² and Asp²⁹⁷ were both mutated to histidine residues. Both PCR and Southern analysis confirmed disruption of gcsap. Neither gcsap mRNA nor GcSAP activity was detected in the disruption mutant. Pathogenicity tests on fruit from three apple cultivars showed that GcSAP was not required for pathogenicity. The disruption mutant grew on medium containing protein as the sole source of nitrogen because G. cingulata secretes a previously undetected peptidase(s). A serine peptidase that had a pH optimum between pH 7.0 and 8.0 and a K _m of 0.25 mM for the synthetic substrate succinyl-Ala–Ala–Pro–Phe-p-nitroanilide was identified.     

Bovine viral diarrhea virus subgenotype 1b in water buffalos (Bubalus bubalis) from Brazil

Tropical Animal Health and Production - Serological studies have characterized the presence of the bovine viral diarrhea virus (BVDV) infection in water buffalo herds worldwide. However, the...