Bacterial colonization affects early organ and gastrointestinal growth in the neonate

Enteral nutrition coupled with bacterial colonization has been shown to have major functional and developmental effects during the postnatal period of neonates. In this study, we developed a highly sensitive premature pig model to elucidate the specific developmental impact of initial bacterial colonization on premature neonates by comparing germ-free and conventionally reared pigs. Thirty-eight preterm pigs (93% gestation) were delivered via caesarean section and reared in either germ-free or conventional isolators for 40–48 h. Pigs were fed either infant milk formula or sow's colostrum. Enteral feeding for two days had trophic effects on gastrointestinal weights, particularly for pancreas, stomach and small intestine (SI). The absence of bacteria in formula fed pigs resulted in a mucosa that appeared more robust and had higher weights for both SI and pancreas, compared to conventional formula fed pigs (P < 0.05). Colostrum fed pigs also had markedly increased mucosal SI proportions, lung and spleen weights compared to conventional formula fed pigs. Colostrum fed pigs and germ-free pigs were similar although stomach, pancreas and distal SI weights were highest for germ-free pigs. The results demonstrate that the initial bacterial colonization interacts with diet to modulate the early neonatal organ development, particularly of the GIT.     

Intermittent suckling improves post-weaning feed uptake but does not change functional gut characteristics of piglets

Suckling pigs were separated from their dam for 24 h on day 21 (1 × 24 h fasting, n = 10) or day 21 and 24 (2 × 24 h fasting, n = 10). Pigs in the control group (n = 10) were not fasted before weaning. All pigs were weaned on day 28 postpartum. Feed intake during the first 4 days post-weaning was higher (P < 0.05) for pigs exposed to 1 × 24 h fasting compared with controls. Water consumption was not affected by fasting prior to weaning. The difference in post-weaning feed uptake was not reflected in any clinical traits, intestinal morphology, or activity of digestive enzymes (maltase, dipeptidylpeptidase IV, aminopeptidases A and N; P > 0.15). In conclusion, a short period of fasting prior to weaning can increase post-weaning feed uptake, although this had no clinical impact under the present experimental conditions.     

人员在岗培训在实施兽药GMP现场管理中的作用

论述了对兽药生产企业进行人员在岗培训的必要性,对实施在岗培训的基本程序和应注意的事项进行了总结,旨在为兽药企业进行GMP现场管理提供参考。     

Content and Composition of Dry Matter in Onion (Allium cepa L.) as Influenced by Developmental Stage at Time of Harvest and Long-term Storage

Some of the chemical changes inside the bulb of onions (Allium cepa L.) and the influence of various harvesting criteria on dry matter content and composition were studied during long-term storage. Onion weight, dry matter content, total N and the non-structural carbohydrates, glucose, fructose, sucrose and total fructans were examined. Significant (P<0.05) interseasonal differences were observed in the weight of the onions, dry matter content, glucose and total non-structural carbohydrates. Furthermore, the dry matter content and composition differed inside the onion bulbs depending on the length of the storage period. The stage of maturation at the time of harvest also significantly influenced the weight of the onions, the dry matter content in individual onions and the fructose content.     

Effects of grazing strategy on limiting nitrate leaching in grazed grass‐clover pastures on coarse sandy soil

Urinations of ruminants on grazed pastures increase the risk of nitrate leaching. The study investigated the effect of reducing the length of the grazing season on nitrate leaching from a coarse sandy, irrigated soil during 2006–2007 and 2007–2008. In both years, precipitation was above the long‐term mean. The experiment was initiated in a 4‐yr‐old grass‐clover sward in south Denmark. Three treatments were as follows grazing only (G), spring cut followed by grazing (CG) and both spring and autumn cuts with summer grazing (CGC). Nitrate leaching was calculated by extracting water isolates from 80 cm depth using ceramic suction cups. Because of considerable variation in measured nitrate concentrations, the 32 installed suction cups per treatment were insufficient to reveal differences between treatments. However, weighted nitrate leaching estimations for G, CG and CGC showed estimated mean nitrate N concentrations of 23, 19 and 13 mg/L for an estimated proportion area occupied by urine patches of 0.33, 0.26 and 0.16, respectively. Thus, N concentrations in G and CG exceeded the EU limit of 11.3 mg N/L. Under the prevailing conditions, the time of urination did not appear important. The estimated background leaching calculated from suction cups presumably not situated under urine patches resulted in mean nitrate N concentrations of 2.6 mg/L.     

Effect of disposition on the relative delayed neurotoxicity potency among leptophos analogs

The oxons of leptophos, its desbromo analog, and its ethoxy analog all inhibit hen brain neurotoxic esterase (NTE) to a similar degree in vitro, but have large differences in minimum effective oral doses for organophosphorus-induced delayed neurotoxicity. The potencies of leptophos and ethoxyleptophos are increased 10-fold when administered to hens intravenously (iv), but the potency of desbromoleptophos is nearly the same whether administered iv or po. Leptophos distributes nearly five times more rapidly from the central compartment than does desbromoleptophos, and its attenuated oral potency may be due to slower net absorption and/or dilution by compartments other than nervous tissue. Intravenously administered phenylphosphonothionates are excreted rapidly into the gastrointestinal tract and a large proportion of the dose is eliminated in the first 48 hr. Indirect evidence indicates that ethoxyleptophos is more rapidly degraded and ethoxyleptophos-inhibited NTE recovers more rapidly than does NTE inhibited by leptophos or desbromomleptophos. It is proposed that differential aging of ethoxyleptophos chiral isomers as well as pharmacokinetic factors may contribute to the apparently anomalous behavior of these three analogs.     

Differences between Brahman and Holstein cows in heat-shock induced alterations of protein synthesis and secretion by oviducts and uterine endometrium

Our objectives were to test differences in protein synthesis and secretion by cultured oviducts and endometrium from Brahman and Holstein cows and the response of those tissues to in vitro heat shock. Explants of oviductal tissue obtained at estrus from Holstein (n = 5) and Brahman (n = 6) cows were cultured at a homeothermic (39 degrees C) or heat shock (43 degrees C) temperature. At 6 h, cultures were pulse-chase labeled (2 h, L[4,5-3H]leucine; 2 h, L-leucine). Endometrial explants were cultured similarly except that pulse labeling was performed for the first 0 to 15, 0 to 30, 30 to 60 and 60 to 90 min following onset of heat shock. A temperature of 43 degrees C increased secretion of nondialyzable 3H-labeled macromolecules by both oviducts of Brahmans but depressed secretion by the oviduct ipsilateral to the side of ovulation of Holsteins. For both breeds, 43 degrees C decreased incorporation of [3H]leucine into trichloroacetic acid (TCA)-precipitable radioactivity in oviducts from the ipsilateral side. Secretion of 3H-labeled macromolecules by pulse-labeled endometrial explants increased at 43 degrees C. Heat shock caused an immediate increase in TCA-precipitable radioactivity in tissue during pulse labeling for Holstein tissues. Incorporation was decreased at 43 degrees C in tissue from Brahmans in the first 30 min and increased thereafter. Incorporation of [3H]thymidine by endometrial explants from Brahmans was increased at 43 degrees C, whereas it was suppressed at 43 degrees C in explants from Holstein cows. Heat shock proteins of 72,000 and 90,000 molecular weight were present in endometrial tissues. A major secretory product of endometrium had a molecular weight of 57,500 for Brahmans and a lower molecular weight (55,600) for Holsteins.