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1.
Age at death from natural scrapie in a flock of Suffolk sheep 总被引:1,自引:0,他引:1
This study deals with natural scrapie in a flock of Suffolk sheep being bred to maximise the incidence of the disease and shows that with succeeding generations the incubation period of the disease became progressively shorter until the flock died out. The most likely explanation for this phenomenon is considered to be an increase in the load of infection. 相似文献
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The potential use of DNA-based methods for detecting airborne inoculum of Leptosphaeria maculans and Pyrenopeziza brassicae , both damaging pathogens of oilseed rape, was investigated. A method for purifying DNA from spores collected using Hirst-type spore samplers and detecting it using polymerase chain reaction (PCR) assays is described. For both pathogens, the sensitivities of the DNA assays were similar for spore-trap samples and pure spore suspensions. As few as 10 spores of L. maculans or P. brassicae could be detected by PCR and spores of both species could be detected against a background of spores of six other species. The method successfully detected spores of P. brassicae collected using spore traps in oilseed rape crops that were infected with P. brassicae. Leptosphaeria maculans spores were detected using spore traps on open ground close to L. maculans -infected oilseed rape stems. The potential use of PCR detection of airborne inoculum in forecasting the diseases caused by these pathogens is discussed. 相似文献
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Landscape Ecology - Maintaining biodiversity in multifunction landscapes is a significant challenge. Planning for the impacts of change requires knowledge of how species respond to landscape... 相似文献
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G.W. Smith J.L. Davis S.M. Smith M.P. Gerard N.B. Campbell D.M. Foster 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2010,24(4):949-955
Background: Despite frequent clinical use, information about the pharmacokinetics and efficacy of pantoprazole in camelids is not available. Objectives: To examine the pharmacokinetics of both IV and SC pantoprazole and to determine whether pantoprazole administration would increase 3rd compartment pH in alpacas. Animals: Six healthy adult alpacas. Methods: Alpacas were fitted with a 3rd compartment cannula for measuring gastric pH. After recovery, alpacas received 1 mg/kg pantoprazole IV, q24h for 3 days or 2 mg/kg SC q24h for 3 days. Alpacas received both IV and SC pantoprazole, with a minimum of 3 weeks between treatments. Third compartment pH was recorded and plasma samples were taken for pharmacokinetic analysis. Results: Pantoprazole induced a slow but sustained increase in 3rd compartment pH when given by both the IV and SC routes. Third compartment pH was significantly increased as compared with baseline values (1.81 ± 0.7; mean ± SD) at 24 (2.47 ± 0.8), 48 (3.53 ± 1.0) and 72 hours (4.03 ± 1.3) after daily IV administration of pantoprazole. Third compartment pH increased from 1.73 ± 0.6 at baseline to 3.05 ± 1.1, 4.02 ± 1.4, and 3.61 ± 1.6 at 24, 48, and 72 hours after SC administration, respectively. Pharmacokinetic analysis demonstrated that pantoprazole had a short elimination half‐life (0.47 + 0.06 h) and a high clearance rate (12.2 ± 2.9 mL/kg/min) after both IV and SC administration. Conclusions and Clinical Relevance: Based on the results of this study, pantoprazole represents a safe and effective drug for increasing 3rd compartment pH in camelids. Either IV or SC administration is likely to be an effective treatment for gastric ulcers. 相似文献
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Intradermal injection of a Culicoides antigen extract (CAgX) induces T lymphocyte and eosinophil accumulation in the skin of horses with sweet itch. Blood mononuclear (BMN) cells from normal ponies proliferate when stimulated by mitogen (phytohaemagglutinin, PHA) or antigen (tetanus toxoid, TT) and, as shown here, release soluble factor(s) that induce eosinophil adherence. CAgX also caused concentration dependent proliferation of BMN cells from sweet itch and normal ponies [stimulation index: 29 (13) and 17 (7) for BMN cells from sweet itch and normal ponies, respectively during the active phase of disease; 4 microg protein ml(-1)CAgX; 168 h]. A heat labile factor(s) which caused eosinophil adherence was also released [sweet itch ponies: 6.0 (1.6) per cent adherence versus 1.3 (0.4) per cent; normal ponies: 6.6 (0.5) per cent adherence versus 0.9 (0.1) per cent for supernatants from CAgX (4 microg protein ml(-1); 48 hours) stimulated versus unstimulated BMN cells, respectively]. These results suggest that soluble proteins released from T lymphocytes could affect eosinophil function in the lesional skin of sweet itch horses. 相似文献
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This paper compares the dinical signs, histopathology, detection of PrPSc protein and PrP genetics of the transmission of BSE to sheep and goats, with the effects of the transmission of natural scrapie from a brain homogenate from a single sheep. After intracerebral and oral inoculations there were similarities in the clinical signs due to the two sources of infection, but there were differences in pathology at the end stage of disease and in the genotypes of the sheep which succumbed to the challenges. The incubation period of BSE was associated with the sheep PrP codon 171 genotype, but the natural scrapie source, despite inducing disease only in known susceptible genotypes, showed no clear association with PrP genotype. 相似文献
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W H Foster 《British poultry science》1972,13(2):123-131
An investigation is described which was designed to evaluate and compare five food additives. The investigation was carried out with about 2400 broilers and the food additives tested were virginiamycin, zinc bacitracin, a nitrofuran derivative, and two arsenical compounds. Only one treatment, one of the arsenicals, produced results economically superior to the control diet. This evaluation of the treatments relative to each other and to the control diet remained substantially similar, as far as the several production characters were concerned, in each of the two seasons in which the investigation was carried out, for each sex and for each of the two breeds of broiler used. The total weight and the weight per unit area of the wall of the small intestine was found to be higher among birds on the control diet than under each of the treatment diets. 相似文献
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