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The uterine and umbilical vessels of 12 pregnant ponies were catheterised to study foetal metabolism. The effects of this procedure on maternal and foetal cardiovascular, respiratory, metabolic and adrenocortical activity were monitored during and after surgery. Premedication with acepromazine-butorphanol-detomidine was followed by induction of anaesthesia with detomidine and ketamine and maintenance, using mechanical ventilation, with halothane in oxygen and nitrous oxide. Mean maternal arterial blood pressure was greater than 70 mmHg during anaesthesia and arterial oxygen tension remained over 100 mmHg. The foetuses were adequately oxygenated but were hypercapnic and lactic acidaemic. Most maternal and foetal blood gases and metabolites had returned to normal by 24 h, although foetal plasma lactate fell more slowly. The maternal adrenocortical discharge was less severe than reported previously and plasma cortisol had fallen to basal levels by 48 h after surgery. Foetal plasma cortisol remained low and did not change during or after surgery. Arterio-venous metabolite and gas tension differences across the uterine and umbilical circulations were slightly greater at operation than in the recovery period, suggesting that uteroplacental perfusion may have been impaired during surgery. Post-operative recovery of the mare and foetus was satisfactory and subsequent problems associated with the foetal catheters were not related to the anaesthesia or surgery. 相似文献
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Abstract. Disturbance of the uranium-lead isotopic system in a metamict Ceylon zircon has been produced in a 2 molal NaCI solution at 500 degrees C and 1000 bars fluid pressure. Loss of radiogenic lead to the extent of 61 percent in 13 days was the most significant effect. The experimental results support the episodic rather than continuous lead-loss interpretation of natural zircon systems utilized in geochronology. 相似文献
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Bagley RS Silver GM Gavin PR 《Journal of the American Animal Hospital Association》2000,36(5):413-415
A 21-kg, seven-year-old, male, mixed-breed Labrador retriever was admitted for incoordination and a head tilt of approximately three months' duration. Ataxia was noted of the trunk and limbs, and there was a head tilt to the right side. Conscious proprioceptive deficits were present in the left thoracic and pelvic limbs (i.e., hemiparesis). These abnormalities were consistent with paradoxical vestibular syndrome and a lesion involving the caudal cerebellar peduncle. A mass lesion consisting primarily of fluid was present on magnetic resonance imaging and at craniectomy. Histopathological diagnosis was a cystic meningioma. Based upon previous reports and experience, the location of this tumor was unusual. 相似文献
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RT NORRIS CL McDONALD RB RICHARDS MW HYDER SP GITTINS GJ NORMAN 《Australian veterinary journal》1990,67(7):244-247
In the first of 2 experiments, a simulated voyage was conducted to examine the effects of various treatments on bodyweight change and feeding frequency of inappetant sheep at the end of lot-feeding (non-feeders). The treatments, applied during simulated shipping, were: normal quantities of feed and length of troughs; extra trough length; extra feed. Adult Merino wethers (n = 108) were used in each treatment. A voyage to the Middle East was then conducted to establish whether shipboard mortality could be reduced by separating non-feeders (n = 305) from feeders (n = 5,620) late in the feedlot hase and housing the groups separately aboard ship. A control group of non-feeders (n = 215) mixed with feeders (n = 5,732) was used for comparison. Bars (marker bars), containing a coloured dye, were attached to feed troughs to mark sheep that fed. Most non-feeders (82%) began eating when placed in shipping pens in both studies. However, there was no significant difference in percentage of sheep that fed between non-feeders given extra trough length or extra feed compared with non-feeders given standard management at any stage of simulated shipping. There was no significant difference in mean bodyweights between treatment groups on days 1, 8 and 15 of simulated shipping. Differences in bodyweight on d 22 were probably associated with different levels of gut fill. Death rates were not significantly different in separated and control groups (1.1%, 0.9%, P = 0.6) in the voyage of 14 d to the Middle East.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Caprine besnoitiosis, caused by the cyst-forming protozoal apicomplexan Besnoitia caprae appears to be endemic in Kenya, Nigeria and Iran, but has yet to be detected in other parts of the world. The infection causes an important parasitic disease of goats in affected developing countries. Bovine besnoitiosis, is a widespread disease of cattle in Africa, Asia (but not Iran) and southern Europe. Recent epidemiological data confirm that the incidence and geographical range of bovine besnoitiosis in Europe is increasing, which is why growing attention has been given to the condition during the past decade. This paper reviews pertinent information on the biology, epidemiology, pathology, clinical signs, diagnosis and control of caprine besnoitiosis, together with its similarities to, and differences from, bovine besnoitiosis. The serious economic consequences of besnoitiosis on goat breeding and local meat and hide industries is also considered. 相似文献