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OBJECTIVE: To evaluate the potential of an implant of a GnRH-agonist (deslorelin) to create a progesterone free animal suitable for studying progesterone (P4) metabolism in intact cows by measuring blood P4 and faecal P4 metabolites. METHODS: Experiment 1: Eighteen non-lactating cycling Holstein-Friesian cows, 4 to 7 years old, were allocated to one of three groups to study plasma P4 concentrations preceding an intravaginal insert. These groups comprised: i) a deslorelin group (GnRH-agonist implanted); ii) a PGF group receiving two injections of prostaglandin (PGF2alpha) 12 days apart; and, iii) an ovariectomised (OVX) group. An intravaginal device (CIDR) was inserted into the vagina of each animal and left in place for 11 days. Plasma P4 concentrations were measured during the study period. Experiment 2: Twelve non-lactating cycling Holstein-Friesian cows, 4 to 7 years old, were allocated to two groups: i) a deslorelin group (GnRH-agonist implanted); and ii) an ovariectomised group. Plasma P4 and faecal P4 metabolites (20-oxo-pregnanes, 20alpha-OH and 20beta-OH) were monitored for a period of 5 weeks. RESULTS: Experiment 1: Average plasma P4 concentration did not differ between the three groups (1.28, 1.43 and 1.55 ng/mL for deslorelin, OVX and PGF cows, respectively, P = 0.8) during the period of supplementation. Experiment 2: There was no difference in plasma P4 (mean plasma P4 < 0.02 ng/mL, P = 0.9) and faecal P4 metabolites between deslorelin and OVX cows 2 weeks after the implantation (P = 0.7). CONCLUSIONS: These data showed that a GnRH-agonist (deslorelin) implant may be used as an alternative to ovariectomy to create a progesterone free animal suitable for studying the metabolism of administered P4.  相似文献   
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Theileria orientalis (also known historically as T. sergenti and T. buffeli) is responsible for benign or non-transforming theileriosis, and exerts its major effect through erythrocyte destruction. The life cycle of T. orientalis is essentially similar to that of other Theileria species, except that the schizonts do not induce transformation and fatal lymphoproliferation. The pathogenesis of anaemia as a result of infection is not clearly established and may be multifaceted. Clinical signs of weakness, reluctance to walk and abortion are early but non-specific indications of disease, particularly if accompanied by a history of cattle being moved. Physical examination may reveal pallor (pale eyes, vaginal mucosa), pyrexia, and elevated heart and respiratory rates. T. orientalis is an economically important parasite of cattle in New Zealand, Australia and Japan, especially where naïve animals are introduced into an endemic area or in animals under stress. Increased awareness of the risks posed by the parasite is required to enable management practices to be implemented to minimise its impact.  相似文献   
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Objective: To investigate the relative efficacy and safety of the anthelmintic naphthalophos in sheep, either given alone or in combination with benzimidazole (fenbendazole and albendazole) or levamisole anthelmintics.
Design: A parasitological study using faecal egg count reduction tests, a validating slaughter trial and field safety trials.
Procedure: Faecal egg count reduction tests were carried out on 13 farms. Naphthalophos and combinations of naphthalophos with levamisole and fenbendazole were included in the drench tests. On one property a controlled efficacy study was carried out to validate faecal egg count reduction test findings. In this trial, sheep were slaughtered 10 days after treatment and the remaining parasites recovered from the gastro-intestinal tract. Safety trials were carried out on eight farms where approximately 50 000 sheep were treated with naphthalophos and albendazole that were tank mixed in the backpack.
Results: The efficacy of naphthalophos alone in faecal egg count reduction tests ranged from 59 to 98% with one test showing 95% reduction. The efficacy of naphthalophos and levamisole ranged from 74 to 100%, with 5 farms showing 95% reduction. The efficacy of naphthalophos and fenbendazole ranged between 88 and 100% with 95% reduction achieved on 10 farms. The controlled efficacy study showed a good correlation between the faecal egg count reduction tests and numbers of parasites recovered, except for Nematodirus where the faecal egg count reduction tests overestimated efficacy. The mortality rate in the safety trials was 0.05%, with most fatalities occurring on one farm.
Conclusion: The combination of naphthalophos and fenbendazole was more effective than a combination of naphthalophos and levamisole, and will provide a sufficiently safe drench rotation option.  相似文献   
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Spatial Variability of Turbulent Mixing in the Abyssal Ocean   总被引:3,自引:0,他引:3  
Ocean microstructure data show that turbulent mixing in the deep Brazil Basin of the South Atlantic Ocean is weak at all depths above smooth abyssal plains and the South American Continental Rise. The diapycnal diffusivity there was estimated to be less than or approximately equal to 0.1 x 10(-4) meters squared per second. In contrast, mixing rates are large throughout the water column above the rough Mid-Atlantic Ridge, and the diffusivity deduced for the bottom-most 150 meters exceeds 5 x 10(-4) meters squared per second. Such patterns in vertical mixing imply that abyssal circulations have complex spatial structures that are linked to the underlying bathymetry.  相似文献   
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Objectives To review the clinicopathological findings in naturally-occurring, histopathologically confirmed cases of feline infectious peritonitis in client-owned cats in Sydney, Australia, with the purpose of identifying factors assisting in the diagnosis of this complex disease syndrome and to characterise the disease as it occurs in this region.
Design Retrospective clinical study: the clinical records of all cats with histopathologically confirmed feline infectious peritonitis at the University Veterinary Centre Sydney and a private cat hospital in Sydney between 1990 and 2002 were reviewed for signalment, history, physical findings, diagnostic test results and the distribution of histological lesions throughout the body at necropsy.
Results Forty-two cats met the inclusion criteria. Significant features of this study that unique to the contemporary literature are i) the over-representation of certain breeds (Burmese, Australian Mist, British Shorthaired, and Cornish Rex) and the under-representation of other breeds (Domestic Shorthaired, Persian); ii) the overrepresentation of males; iii) the tendency for effusive disease in Australian Mist cats and non-effusive disease in Burmese; iv) the even age distribution of disease seen in cats older than 2 years-of-age; and v) the presence of fulminant immune-mediated haemolytic anaemia in two cats in this study.
Conclusion The study highlights the diverse range of clinical manifestations and the complexities experienced by clinicians in diagnosing this fatal disease. Some aspects of the epidemiology and clinical manifestations of feline infectious peritonitis appear different to the disease encountered in Europe and North America, most notably the over-representation of specific breeds and the presence of immune-mediated haemolytic anaemia.  相似文献   
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