Toxicology of selected pesticides, drugs, and chemicals. Pyrethrin and pyrethroid insecticides     

W M Valentine 《Veterinary Clinics of North America: Small Animal Practice》1990,20(2):375-382

Pyrethroids have a wide spectrum of insecticidal potency, vertebrate toxicity, and environmental stability. The exceptionally high selectivity ratios of pyrethrins and pyrethroids have resulted in their use for insect control in numerous formulations. A primary effect of pyrethroids is to slow the closing of the sodium activation gate in nerve cells. All pyrethroids have essentially the same basic mechanism of action on voltage-dependent sodium channels but differ in the magnitude of effect. Based on clinical signs, electrophysiologic responses, and chemical structure, pyrethroids can be classified as Type I or Type II. Inhibition of the GABAA receptor appears to be an additional mechanism of Type II pyrethroids. Clinical signs in small animals during a pyrethroid toxicosis vary but are generally attributable to neural dysfunction. Treatment consists of decontamination procedures and application of appropriate symptomatic care, including control of seizures if necessary.  相似文献   

Visceral myiasis caused by Musca domestica in a cat     

C H Gardiner  V S James  B A Valentine 《Journal of the American Veterinary Medical Association》1983,182(1):68-69

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Multiple hepatic abscesses and peritonitis caused by eugonic fermenter-4 bacilli in a pup     

B A Valentine  W P Porter 《Journal of the American Veterinary Medical Association》1983,183(11):1324-1325

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Acute intravascular hemolysis in the black rhinoceros: erythrocyte enzymes and metabolic intermediates     

D E Paglia  W N Valentine  R E Miller  M Nakatani  R A Brockway 《American journal of veterinary research》1986,47(6):1321-1325

Enzymes of aerobic and anaerobic glycolysis, glutathione cycling, and nucleotide metabolism were assayed on erythrocytes from 7 healthy rhinoceroses, 2 rhinoceroses during periods of intravascular hemolysis, and 1 rhinoceros without clinical signs of illness, which was the mother of 3 offspring with intravascular hemolytic syndrome. Measurements also were made of erythrocyte concentrations of glycolytic intermediates, adenine nucleotides, and glutathione. Although comparison of results for healthy and affected rhinoceroses did not identify an enzyme abnormality as a cause for the hemolytic syndrome, the data provided information regarding the metabolic characteristics of erythrocytes from healthy rhinoceroses.  相似文献   

Systems thinking and practices in the education of agriculturalists     

Richard J. Bawden  Robert D. Macadam  Roger J. Packham  Ian Valentine 《Agricultural Systems》1984,13(4):205-225

A systems approach has been taken to a review of agricultural education programmes and as the essential theme of resultant curricula at Hawkesbury Agricultural College in Australia. The systems thinking and practices which have guided, and been shaped by, the innovations are outlined, and the rationale and framework of the major programme are described. The subsequent emphasis has been placed on effective learning for agricultural managers and their technologist advisors. It is argued that problem solving and learning are essentially the same psychological processes and that taking a systems approach to investigating problem situations provides a more useful paradigm for learning about agriculture than reductionist, discipline-based approaches. Experiential learning and autonomy in learning are seen as consistent with this and are basic features of the programmes. A conceptual framework for problem solving that incorporates soft and hard systems and scientific reductionist methodologies has been developed. A contingency approach to situation improving is emerging as a less restrictive and more realistic alternative to a normative approach to problem solving.  相似文献   

Peripheral giant cell granuloma in a cat   总被引：1，自引：0，他引：1  

J T Rothwell  B A Valentine  V M Eng 《Journal of the American Veterinary Medical Association》1988,192(8):1105-1106

A gingival mass excised from a cat was determined to be a peripheral giant cell granuloma. Characteristic histologic features were large numbers of multinucleated giant cells intermixed with mononuclear mesenchymal cells in a loose fibrovascular stroma. The lesion recurred twice, indicating that these non-neoplastic growths may be locally invasive.  相似文献   

Central giant cell granuloma in the mandible of a dog     

B A Valentine  J A Flanders  W V Corapi  V T Rendano 《Journal of the American Veterinary Medical Association》1988,192(5):657-658

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Phanerozoic taxonomic diversity: a test of alternate models     

Valentine JW 《Science (New York, N.Y.)》1973,180(4090):1078-1079

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A retrospective study of spinal cord lesions in goats submitted to 3 veterinary diagnostic laboratories     

Andrew L. Allen  Brad A. Goupil  Beth A. Valentine 《The Canadian veterinary journal. La revue veterinaire canadienne》2012,53(6):639-642

A retrospective study of spinal cord lesions in goats was conducted to identify the range of lesions and diseases recognized and to make recommendations regarding the best tissues to examine and tests to conduct in order to maximize the likelihood of arriving at a definitive etiologic diagnosis in goats with clinical signs referable to the spinal cord. Twenty-seven goats with a spinal cord lesion were identified. The most common lesion recognized, in 13 of 27 goats, was degenerative myelopathy. Eight goats with degenerative myelopathy were diagnosed with copper deficiency. Non-suppurative inflammation due to caprine arthritis encephalitis virus, necrosis due to parasite larvae migration, and neoplasia were each diagnosed 3 times. Based on these findings, it is recommended that, in addition to careful handling and histologic examination of the spinal cord, samples of other tissues, including the brain, liver, and serum, be collected for ancillary testing if warranted.  相似文献   

Primary ureteral giant cell sarcoma in a Pomeranian     

Rigas JD  Smith TJ  Gorman ME  Valentine BA  Simpson JM  Seguin B 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2012,41(1):141-146

An 8-year-old male neutered Pomeranian dog was presented to the Veterinary Teaching Hospital at Oregon State University for surgical treatment of hydronephrosis of the left kidney and a left cranial abdominal mass. A primary ureteral mass was found during exploratory surgery, and the mass was resected and ureteral anastomosis was performed. Cytologic evaluation of the mass revealed 3 distinct cell populations, including a large number of multinucleated giant cells, a moderate number of thin spindle-shaped cells, and cohesive clusters of transitional epithelial cells. The cytologic diagnosis was giant cell sarcoma. The diagnosis was confirmed by histologic examination, and immunohistochemical staining was performed. The spindle-shaped cells and multinucleated giant cells were both immunoreactive for vimentin and spindle-shaped cells for S-100. Tumor cells did not express wide-spectrum cytokeratin, broad-spectrum muscle actin, smooth muscle actin, sarcomeric actin, desmin, BLA36, Mac 387, synaptophysin, neuron-specific enolase, glial fibrillary acid protein, or von Willebrand factor. These findings are most consistent with an anaplastic sarcoma with giant cells. This is the first case report of a primary ureteral giant cell sarcoma in a dog.  相似文献