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191.
P.E. Peterson J.J. Short R. Tarara C. Valverde E. Rothgarn A.G. Hendrickx 《Journal of medical primatology》1997,26(5):267-275
Abstract: This paper summarizes the spontaneous incidence of congenital defects in the rhesus and cynomolgus macaque colonies (Macaca mulatta and M. fascicularis) at the California Regional Primate Research Center. The computerized database used in this analysis included fetuses, term infants, juveniles, and adults that underwent a necropsy procedure over a 14-year period (1983–1996). The calculated malformation rates were 0.9% (40/4,390) and 0.3% (3/965) for the rhesus and cynomolgus monkey, respectively. Most of the observed malformations in both species affected the musculoskeletal and the cardiovascular systems, while a smaller number of defects were observed in the gastrointestinal, urogenital, endocrine, and central nervous systems. Inbreeding did not contribute to the spontaneous malformation incidence and there was no predilection for sex (male vs. female) or housing (indoors vs. outdoors) among the malformed cases. This spontaneous malformation database in our macaque colony aids in the interpretation of defects that occur in an experimental study as well as in the ongoing assessment of a healthy nonhuman primate breeding colony. 相似文献
192.
Cardiovascular and pulmonary effects of pro-pofol, a relatively new nonbarbiturate intravenous anaesthetic, were assessed and com-pared in 22 male and female dogs. Dogs in group 1 did not receive any premedication prior to 6.6 mg/kg IV propofol, group 2 was premedicated with atropine (0.02 mg/kg IM) and the α2-agonist medetomidine (10 μg/kg IM), and group 3 received the same premedication agents as group 2, but the medetomidine effects were reversed by the α2-antagonist atipamezole (30 μg/kg IV) after 30 min of anaesthesia. Each dog in groups 2 and 3 received a propofol induction dose of 2.2 mg/kg IV The anaesthetic du-ration was shortest with propofol alone and prolonged with medetomidine as a premedication which was reversible with atipamezole. In group 1, the most prominent effects were a temporary drop in diastolic arterial blood pressure (26% and 24%) at 2 and 5 min post-propofol, respectively and a drop in respiratory frequency (41%) 2 min after pro-pofol induction. Similar respiratory depression was observed in groups 2 and 3 (20% and 48%, respectively) at the same time. Apnea was not observed. An increase in systemic arterial blood pressure was observed throughout the trial in groups 2 and 3 un-til dogs recovered or were reversed with atipamezole. Medetomidine significantly re-duces propofol dosage requirements. Safe and effective injectable anaesthesia was pro-duced by propofol in this group of dogs. The frequency of respiratory depression would suggest in clinical usage, the practitioner should be aware oxygen supplementation is the treatment of choice should apnea occur. 相似文献
193.
D. M. Burdick M. Dionne R. M. Boumans F. T. Short 《Wetlands Ecology and Management》1997,4(2):129-144
Efforts are underway to restore tidal flow in New England salt marshes that were negatively impacted by tidal restrictions. We evaluated a planned tidal restoration at Mill Brook Marsh (New Hampshire) and at Drakes Island Marsh (Maine) where partial tidal restoration inadvertently occurred. Salt marsh functions were evaluated in both marshes to determine the impacts from tidal restriction and the responses following restoration. Physical and biological indicators of salt marsh functions (tidal range, surface elevations, soil water levels and salinities, plant cover, and fish use) were measured and compared to those from nonimpounded reference sites. Common impacts from tidal restrictions at both sites were: loss of tidal flooding, declines in surface elevation, reduced soil salinity, replacement of salt marsh vegetation by fresh and brackish plants, and loss of fish use of the marsh.Water levels, soil salinities and fish use increased immediately following tidal restoration. Salt-intolerant vegetation was killed within months. After two years, mildly salt-tolerant vegetation had been largely replaced in Mill Brook Marsh by several species characteristic of both high and low salt marshes. Eight years after the unplanned, partial tidal restoration at Drakes Island Marsh, the vegetation was dominated bySpartina alterniflora, a characteristic species of low marsh habitat.Hydrologic restoration that allowed for unrestricted saltwater exchange at Mill Brook restored salt marsh functions relatively quickly in comparison to the partial tidal restoration at Drakes Island, where full tidal exchange was not achieved. The irregular tidal regime at Drakes Island resulted in vegetation cover and patterns dissimilar to those of the high marsh used as a reference. The proper hydrologic regime (flooding height, duration and frequency) is essential to promote the rapid recovery of salt marsh functions. We predict that functional recovery will be relatively quick at Mill Brook, but believe that the habitat at Drakes Island will not become equivalent to that of the reference marsh unless the hydrology is further modified.Corresponding Editor: R.E. Turner Manuseript 相似文献
194.
By the observation of chemically induced dynamic nuclear polarization in (15)N NMR spectroscopy it has been shown that nitration of N-acetyltyrosine, even under acidic conditions, is largely a radical process. In the alkaline reaction of tyrosine with peroxynitrite the main products are nitrite and nitrate, both produced by a radical pathway, and tyrosine nitration is a minor reaction. It is suggested that tyrosine catalyzes the production of NO(*)(2) and HO(*) from peroxynitrite. 相似文献
195.
Mutations in two pollen self‐incompatibility factors in geographically marginal populations of Solanum habrochaites impact mating system transitions and reproductive isolation
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196.
Cardiolipin (CL) synthetase from Staphylococcus aureus catalyzes the complete conversion of two molecules of phosphatidylglycerol (PG) to one molecule of CL and one molecule of glycerol. The fatty acids and phosphates of the two PG molecules can be quantitatively recovered in the CL. The enzyme is membrane-bound, shows a linear relationship with the product formed between 10 and 125 mug of membrane protein, has a pH optimum at 4.4, a temperature optimum between 37 and 45 C, a K(m) for PG of 2.1 x 10(-4)m, a V(max) of 200 nmoles of CL per min per mg of membrane protein, and does not require monovalent or divalent metals for activity. The enzyme has no nucleotide requirement and is not affected by prolonged dialysis, and treatment of the enzyme with charcoal has no effect on its activity. The enzyme has no phosphomonoesterase or phosphodiesterase activity, does not act on CL, is specific for PG, and CL and glycerol are the sole products of its activity. Other lipids do not stimulate or inhibit its activity. The enzyme is inhibited by organic solvents and some detergents. There is sufficient CL synthetase activity to account for CL synthesis during exponential growth. Inhibition of CL hydrolysis during growth results in an increase in CL that is balanced by a loss of PG. The activity of CL synthetase is not affected by cytidine diphosphate diglyceride but is inhibited competitively by the product, CL. 相似文献
197.
Polysaccharide-containing material was located by histochemical staining on ultrathin sections of Bacillus cereus and several clostridial species during various phases of growth. These components were located along the cell wall in young vegetative cells and along the developing cortex in sporulating cells. In B. cereus any carbohydrate-containing material present along the forespore membrane was too small to be detected by direct staining. However, in three clostridial species such material was detected at all stages of forespore development. 相似文献
198.
The lipid composition of the chemoautotroph Ferrobacillus ferrooxidans has been examined. Fatty acids represent 2% of the dry weight of the cells and 86% of the total are extractable with organic solvents. About 25% of the total fatty acids are associated with diacyl phospholipids. Polar carotenoids, the benzoquinone coenzyme Q-8, and most of the fatty acids are present in the neutral lipids. The phospholipids have been identified as phosphatidyl monomethylethanolamine (42%), phosphatidyl glycerol (23%), phosphatidyl ethanolamine (20%), cardiolipin (13%), phosphatidyl choline (1.5%), and phosphatidyl dimethylethanolamine (1%) by chromatography of the diacyl lipids, by chromatography in four systems of the glycerol phosphate esters derived from the lipids by mild alkaline methanolysis, and by chromatographic identification of the products of acid hydrolysis of the esters. No trace of phosphatidylserine (PS), glycerolphosphorylserine, or serine could be detected in the lipid extract or in derivatives of that extract. This casts some doubt on the postulated involvement of PS in iron metabolism. After growth in the presence of (14)C and (32)P, there was essentially no difference in the turnover of either isotope in the glycerolphosphate ester derived from each lipid in cells grown at pH 1.5 or 3.5. 相似文献
199.
C E Short R C Harvey F E Fisher J N Cunningham D M Rose J Gelbfish E Weiss E Grossi 《Laboratory animal science》1987,37(1):94-99
The purpose of this study was to determine the factors influencing successful experimental cardiopulmonary bypass studies using pulsatile flow perfusion and the medications and methodology necessary to produce successful bypass in calves. In six calves showing no cardiopulmonary pathology prior to bypass procedures, successful anesthesia and surgical intervention was accomplished. Animals were maintained on 5 hours of pulsatile flow bypass perfusion. Successful recovery from the procedures was accomplished. In two calves with pre-existing pulmonary pathology, anesthetic and surgical intervention was accomplished with the utilization of extensive anesthetic management and cardiac supportive medications until the animals could be initiated into 5 hours of pulsatile flow bypass perfusion, in spite of major pulmonary dysfunction. In these two animals, attempts to resuscitate upon termination of pulsatile flow perfusion were unsuccessful due to pre-existing excessive lesions in the lungs. This study shows a contrast between complete success of a pulsatile flow system in normal subjects versus the ultimate failure in experimental animals with pre-existing pulmonary pathology. The inability of experimental calves with a diseased lung to resume spontaneous cardiopulmonary function after the challenges of thoracic intervention indicates the unsuitability of animals with marked pre-existing pulmonary disease status for use in cardiopulmonary bypass studies. 相似文献
200.