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61.
Monoamines are important brain neurotransmitters. An investigation was carried out to determine if hypomagnesaemic tetany was associated with alterations in regional brain monoamine concentrations in bovines. The results, established in cows with normal magnesium status, demonstrated that regional differences existed in the distribution and concentration of brain monoamines in the adult bovine, which were similar to those in other species. In magnesium-deficient cows, severe hypomagnesaemia and lowered cerebrospinal fluid (CSF) magnesium concentrations were associated with significant alterations in monoamine concentrations in some brain regions. Alterations in 3,4-dihydroxyphenylalanine (DOPA) and dihydroxyphenylacetic acid (DOPAC) concentrations in the corpus striatum, and dopamine (DA) in the cerebral cortex and cerebellum were recorded. These regions play an important role in both voluntary and involuntary motor function, and therefore these alterations may play a role in the aetiology of hypomagnesaemic tetany. However, there was no significant change in DA concentrations in the corpus striatum (the main dopaminergic region in the brain) associated with hypomagnesaemia. In addition, a significantly lower norepinephrine (NE) concentration in the corpus striatum of hypomagnesaemic animals was also recorded. Norephinephrine is generally excitatory and therefore lowered NE concentrations would be expected to result in depression rather than stimulation of motor function. 相似文献
62.
Genetic characterization of canine rotavirus isolated from a puppy in Korea and experimental reproduction of disease. 总被引:3,自引:0,他引:3
63.
Marie Ren Gramer Jee Hoon Lee Young Ki Choi Sagar M. Goyal Han Soo Joo 《Canadian journal of veterinary research》2007,71(3):201-206
The H3N2 subtype of influenza A viruses isolated from pigs in the United States and Canada has shown both genetic and antigenic diversity. The objective of this study was to determine the serologic and genetic characteristics of contemporary strains of these viruses. Genetic analysis of 18 reference strains and 8 selected strains demonstrated differences in 1% to 9% of the nucleotides of the hemagglutinin (HA) gene. Phylogenetic analysis of the HA gene revealed 3 genetic clusters, as well as divergence of cluster III viruses from a cluster III prototype virus (A/Swine/Illinois/21587/99). By means of 1-way cross-hemagglutination inhibition with antiserum against 5 field isolates and 3 vaccine viruses, most of 97 isolates tested could be placed in 1 of 3 serogroups. The several isolates that did not react with any antiserum were in genetic cluster III, which suggests that continuous antigenic drift in cluster III may have resulted in virus variants. The efficacy of commercial vaccines against these virus variants should be evaluated with vaccination and challenge studies. 相似文献
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66.
K. LEANN KUEBELBECK DVM DONNIE E. SLONE DVM MS Diplomate ACVS KIM A. MAY DVM 《Veterinary surgery : VS》1998,27(2):132-137
Objective —To determine if omentectomy would decrease the frequency of postoperative intraabdominal adhesions. Study Design —Retrospective study. Animals or Sample Population—44 horses that had either two ventral median celiotomies or a ventral median celiotomy and a necropsy more than 4 days later; 19 of these horses had their omentum removed at the initial surgery. Methods —Data retrieved from the records included location and type of intraabdominal adhesions; location of the surgical lesion; relationship of adhesions to the surgical lesion; surgical procedures; duration of initial surgery; time interval between procedures; age, gender, and breed of the horse; and clinical outcome. Fisher's exact test was used to evaluate the association between categorical explanatory and outcome variables. The effect of potential risk factors on the incidence rate of adhesion formation was estimated using a proportional hazards regression model. Results —Of 25 horses in the nonomentectomy group, 15 (60%) had postoperative adhesions that resulted in the need for a second surgical intervention, whereas of 19 horses that had omentectomy initially, only 4 (21%) had postoperative adhesions that required a second procedure. Rate of adhesion formation was higher in horses that did not have omentectomy initially (incidence ratio rate [IRR], 0.46; 90% confidence interval [CI], 0.18 to 1.19). At initial surgery, 24 horses had a small intestinal lesion, and 20 horses had a large intestinal lesion. Fifteen horses (63%) with small intestinal lesions subsequently developed adhesions compared with four horses (20%) with an initial large intestinal lesion (P= .006). At the second procedure, small intestine lesions were identified in 32 horses and large intestine lesions in 12 horses (1 horse had both small and large intestine lesions), and 1 horse had a gastric lesion. Adhesions were identified as the cause of colic signs in 19 (61%) horses with small intestinal lesions and in none of the horses with large intestine lesions. The frequency of adhesion development leading to colic associated with only the small intestine at the second surgery or necropsy was significantly greater (P= .001) than the frequency only in the large intestine. Conclusions —Omentectomy reduced the rate of postoperative adhesion formation. Adhesions are more likely to occur after small intestinal surgery and if they do occur likely involve the small intestine. Clinical Relevance —Omentectomy is a safe procedure and should be considered prophylactically for reduction of adhesion formation after abdominal surgery in horses. 相似文献
67.
Physiological Responses of Rainbow Trout Oncorhynchus mykiss to Crowding and Anesthesia with AQUI-S™
Glen W. Davidson Peter S. Davie Graham Young Reece T. Fowler 《Journal of the World Aquaculture Society》2000,31(1):105-114
Abstract.— Following exposure to the anesthetic AQUI-S™, plasma cortisol concentration in immature rainbow trout was measured as (mean) 293 ± 48 ng/ mL, which was significantly ( P > 0.05) higher than the mean concentration in resting fish. Cortisol concentrations remained significantly ( P > 0.05) elevated for at least 24 h after treatment. This was accompanied by a significant increase and decrease in hematocrit and plasma potassium, respectively. These perturbations continued for at least 48 h following recovery from anesthesia. Plasma concentrations of total protein and sodium remained unchanged following anesthesia with AQUI-S™. Crowding stress is commonly encountered by fish during manipulation in aquaculture situations. Anesthetising fish prior to, and during, manipulation may reduce the associated stress. Changes in cortisol values resulting from crowding (30 min; 0.1 kg/L) during anesthesia with AQUI-S™ were not appreciably different from those in fish crowded without anesthesia. Thus, anesthesia with AQUI-S™ at the recommended dose of 17 mg/L did not appear to be effective for alleviating the stress of crowding under the conditions of our experiments. 相似文献
68.
The pathogenesis of velogenic Newcastle disease virus infection of chickens of different ages and different levels of immunity 总被引:2,自引:0,他引:2
Chickens of 7 weeks or 20 weeks of age were divided into three groups according to their antibody status (high, low, absent) and were infected with a velogenic viscerotropic Newcastle disease virus. To follow patterns of viral replication, birds were necropsied at regular intervals up to 22 days and organs were sampled from each bird. In non-immune birds, virus could be isolated from all organs examined. In birds with antibody, virus was most frequently isolated from the proventriculus, cecal tonsil, bursa, and brain. However, because no one organ could be recommended for all situations, all four should be sampled for field diagnosis. In immune birds, although clinical signs were either mild or absent, widespread virus replication occurred up to 19 days post-challenge. 相似文献
69.
R D Zenoble R J Kemppainen D W Young J W Carpenter 《Journal of the American Veterinary Medical Association》1985,187(11):1119-1120
The effect of ACTH on plasma corticosterone and cortisol was determined in 12 eagles (Haliaeetus leucocephalus) and in 6 Andean condors (Vultur gryphus). In all raptors, the concentration of plasma corticosterone was substantially greater than that of cortisol. After ACTH administration, the eagles had a marked increase (P less than 0.001) in plasma corticosterone concentrations, but not in plasma cortisol. Administration of saline solution did not induce increased plasma corticosterone concentrations in the eagles. The condors had a smaller increase (P less than 0.002) in plasma corticosterone concentrations after ACTH administration, as compared with that of the eagles. However, administration of saline solution in 2 condors resulted in an increase in corticosterone similar to the increase after ACTH administration. In the condor, a stress-related release of endogenous ACTH may have an effect similar to that induced by exogenously administered ACTH. Plasma cortisol concentrations did not increase significantly after administration of ACTH or saline solution in either raptor species. 相似文献
70.
Cardiorespiratory responses to electrical stimulation of the buccal mucosa in ponies 总被引:1,自引:0,他引:1
S S Young 《Research in veterinary science》1990,49(3):268-274
The cardiovascular and respiratory responses to electrical stimulation of the buccal mucosa under general anaesthesia in ponies were measured in order to provide some insight into the cardiorespiratory effects of anaesthesia in equidae. This knowledge may be useful for reducing morbidity during clinical anaesthesia in horses. Anaesthesia was induced with intravenous thiopentone and maintained with 1.3 per cent inspired halothane in oxygen. Arterial blood pressure, heart rate, minute volume, tidal volume, respiratory rate, arterial blood gas tensions and clinical signs of anaesthetic depth were recorded while the buccal mucous membrane was stimulated electrically. A rise in arterial blood pressure was the most consistent response detected along with clinical signs. The response of individual animals varied considerably. Alterations of respiratory pattern sometimes occurred during stimulation but there was no consistent pattern of change in any animal. 相似文献