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521.
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The effects of a short period (10 minutes) of halothane anaesthesia upon skeletal muscle have been examined in broiler chickens. Integrity of the muscle membrane was assessed by measurement of plasma activities of intracellular enzymes. Creatine kinase activity was greatly increased during the first 12 hours post-anaesthesia and remained elevated for at least 48 hours. Lactate dehydrogenase activity exhibited a similar pattern which was less pronounced. Halothane anaesthesia induced transient hypercapnic acidosis and hypokalemia and increased corticosterone secretion but there was no significant effect upon deep body temperature. It is proposed that halothane may act directly upon skeletal muscle, perhaps influencing intracellular calcium homeostasis, to alter membrane permeability and increase enzyme efflux reflecting a degree of post-anaesthetic muscle damage. The transient changes in electrolyte and acid-base balance may contribute to these effects. Precautions should be taken to minimise the incidence or extent of halothane induced myopathy in birds particularly in rapidly growing broiler chickens where susceptibility may be increased.  相似文献   
523.
The use of the penicillins in veterinary dermatology is discussed. An outline is provided of the main penicillins used in the veterinary field. These include benzyl penicillin, penicillin V, ampicillin, amoxycillin, co-amoxiclav and oxacillin. An increase in β-lactamase production among strains of Staphylococcus intermedius , the principal canine pathogen in pyoderma, has been seen in recent years. Thus only those penicillins with resistance to β-lactamase (co-amoxiclav or isoxazolyl penicillins) are likely to be of value in treating canine pyoderma. However, feline, porcine and equine staphylococcal dermatoses, and other veterinary dermatoses such as the actinomycoses, dermatophilosis and erysipelothrix, usually respond well to most penicillins, whether or not they resist β-lactamase.  相似文献   
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Comparative, quantitative disease responses to intranasal chlamydial infection in susceptible mice and others vaccinated either intraperitoneally or intranasally three weeks previously are recorded. Resistance to challenge was confirmed in both vaccinated groups being manifest by reduced mortality, inhibited growth and survival of the organism, and increased lung macrophage response  相似文献   
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Significant reductions in adult worm burdens in lambs less than six months old infected with 5000 third stage Haemonchus contortus larvae were achieved following the combination of a single transfer factor treatment with multiple parenteral treatments of adult parasitic antigen and precipitated immunoglobulin. Specific cellular responses in the abomasa associated with individual treatments were discernible in all the experimental groups and quantitative differences in these responses reflected the varying treatment levels and treatment combinations. The reactions associated with transfer factor were similar to immediate type hypersensitivity responses and their role as possible effector mechanisms in correcting partial immune incompetency in lambs is discussed.  相似文献   
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The technique of embryo transfer was used to investigate the maternal transmission of scrapie in sheep. Embryo donor ewes were experimentally infected with scrapie (all eventually developing the disease) and artificially inseminated six months later with semen from an uninfected scrapie-susceptible ram. Embryos were harvested five and six days after insemination and transferred by laparoscopy, unwashed, into recipient ewes which had been genetically selected for very low susceptibility to scrapie. Six of the 26 lambs born to these recipients developed scrapie.  相似文献   
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