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Biomedical subjects

J P Orr

Publications and source records attributed to J P Orr.

At least 19 recordsLinked to original sources
PubMed2005

Neosporosis in a young dog presenting with dermatitis and neuromuscular signs.

A 16-week-old, male boxer dog developed multifocal nodular dermatitis followed by rapidly progressive and fatal neuromuscular disease. Protozoal tachyzoites were demonstrated by aspiration and biopsy of dermal lesions. Necropsy and histology revealed necrotising inflammation associated with intralesional protozoal organisms in various organs including the brain, heart, skeletal muscle and skin. Serology suggested active infection with Neospora caninum. Immunohistochemistry provided a definitive diagnosis. Dermatitis is a finding rarely associated with juvenile neosporosis. The possible role of immunosuppression is discussed.

Animals↗
PubMed1999

Examination of adenovirus-types in intestinal vascular endothelial inclusions in fatal cases of enteric disease in cattle, by in situ hybridisation.

There have been occasional reports in the literature of a severe naturally occurring enteric disease of cattle in which adenoviral inclusions were found in intestinal vascular endothelium. Bovine adenovirus type 10 (BAV-10) was identified by in situ hybridisation (ISH) in the inclusions of all 13 such cattle detected in Northern Ireland [Smyth, J.A., Benkö, M., Moffett, D.A., Harrach, B., 1996. J. Clin. Microbiol. 34, 1270-1274]. The present paper describes ISH examination of the vascular endothelial inclusion bodies in a further seventeen cattle with enteric disease, from Canada, Great Britain, Italy and The Netherlands. BAV-10 was identified in the inclusions of ten cases, and Subgroup 2 BAVs in six cases. BAV-10 was identified in cattle from Canada, The Netherlands and Great Britain. This is the first recognition of BAV-10 infection outside Northern Ireland and New Zealand. The results also show that at least two adenovirus serotypes may induce inclusion bodies in intestinal vascular endothelium of cattle. It will, therefore, be difficult in the short term to develop a simple test to allow diagnosis of this form of adenoviral infection in living animals, and thus to determine the relationship between it and clinical disease.

Adenoviridae↗
PubMed1997

Investigation of the selenium status of aborted calves with cardiac failure and myocardial necrosis.

Lesions of heart failure, specifically cardiac dilation or hypertrophy along with a nodular liver (chronic passive congestion) and ascites, have been found in 4-5% of aborted bovine fetuses. In this study, a group of 22 such fetuses was compared with groups of aborted fetuses without lesions of heart failure and with nonaborted fetuses obtained from a slaughterhouse. The fetuses were necropsied, tissues were taken for histopathology, and samples were collected for routine bacteriologic and virologic examinations. Liver and kidney tissue was saved for selenium analysis. Histopathologic examinations of myocardium of fetuses with cardiac failure revealed myocardial necrosis and mineralization in 7 fetuses, lymphocytic myocarditis in 5 fetuses, myocardial fibrosis in 5 fetuses, or no microscopic lesions in 5 fetuses. Mean liver selenium levels were 5.5 mumol/kg in the fetuses with heart lesions, 6.5 mumol/kg in the fetuses without heart lesions and 7.5 mumol/kg in fetuses from the slaughterhouse; these differences were statistically significant. The results suggest that selenium deficiency in bovine fetuses may cause myocardial necrosis and heart failure. This study also provides data on normal liver and kidney selenium levels in bovine fetuses from the analyses of 19 nonaborted fetuses.

Abortion, Veterinary↗
PubMed1996

Chromosomal aneuploidy associated with spontaneous abortions and neonatal losses in cattle.

Pericardial sac samples from 77 bovine aborted fetuses and stillborn calves were submitted for tissue culture; cells from 55 of these samples were grown successfully in culture. Six of the 55 karyotyped fetuses (10.7%) had an abnormal chromosome complement, in 3 of which (5.5%) the abnormality was probably the cause of death. This level of abnormality is relatively high when one considers that most fetuses were >8 months gestational age. Approximately 5-7% of human stillbirths and 50% of first-trimester aborted fetuses have chromosome anomalies. If a similar situation exists in cattle, as suggested by these data, chromosome abnormalities may be a major cause of early fetal loss in cattle. Most chromosomally abnormal fetuses had multiple malformations, which suggests that the diagnostic use of chromosome analysis is most cost effective for malformed fetuses and newborns. Twins were present in a higher proportion of these fetuses than expected based on their incidence among liveborn cattle.

Abortion, Veterinary↗
PubMed1984

Fibrosarcoma affecting the mammary gland of a cow.

A highly malignant fibrosarcoma which arose in or close to the mammary gland of a 12 year old Ayrshire cow, with metastases in local lymph nodes, lungs, liver, kidney and adrenal glands has been described. The tumors were densely cellular and consisted of interweaving bands of fusiform cells with a high mitotic index. Infiltration of normal tissues and invasion of blood vessels were characteristic features. Ultrastructural study of the cells revealed mesenchymal cells with abundance of rough endoplasmic reticulum and cytoplasmic vesicles and they were closely invested with collagen fibers.

Animals↗
PubMed1981

Chronic granulocytic leukemia in a horse.

A nine year old quarter horse exhibited progressive weight loss and inappetance over a 47 day period. There was clinical evidence of pleuritis and pneumonia substantiated by leukocytosis and elevated protein in pleural fluid. Over the entire period the horse was neutropenic and had circulating abnormal immature granulocytes and low numbers of blast cells. Anemia and thrombocytopenia progressively worsened. Bone marrow examination revealed very few mature granulocytes but large numbers of immature cells of the granulocytic series and marked megaloblastic transformation of erythroid cells. These findings were consistent with chronic granulocytic leukemia.

Animals↗
PubMed1981

Possible monensin poisoning in a group of bulls.

Apparent monensin toxicity was diagnosed in a group of Maine Anjou bulls placed on a performance test in a commercial feedyard in east central Saskatchewan. The clinical, hematological and pathological findings were consistent with a diagnosis of congestive heart failure. The suspected dose ingested by the bulls was based on a mixing error evident from the feedlot's daily feed journal. When deaths in the group of bulls began to occur, the intoxicating feedstuff was no longer available for confirmation of the diagnosis.

Animals↗
PubMed1981

Unusual skeletal deformities in calves in a Saskatchewan beef herd.

A very high incidence of posterior paresis in growing calves was casued by abnormal development of the vertebral column. The pathological changes were focal premature synostoses of vertebral growth plates with resulting reduction in size of the vertebral canal. Malacic changes were seen in sections from all areas of the spinal cord. Abnormalities in growth of the cranium and appendicular skeleton were also present. The growth plates in the cranial base were prematurely closed and the cranial cavity was shortened. Long bones were shortened and distorted. Possible causes include teratogenic plants or chemicals, mineral deficiencies, and hypervitaminosis A.

Animals↗
PubMed1977

Investigation of the vascular supply of the pectoral muscles of the domestic turkey and comparison of experimentally produced infarcts with naturally occurring deep pectoral myopathy.

Naturally occurring deep pectoral myopathy in 9 chickens and 6 turkeys was reviewed. The arterial blood supply to the pectoral and supracoracoid muscles was studied in normal mature turkey hens by preparation of arterial casts following perfusion with methyl methacrylate. Also, a latex-perfused turkey was dissected and the blood vessels supplying these muscles were identified. Six mature turkeys (under general anesthesia) were subjected to unilateral surgical obstruction of selected cranial and caudal pectoral arteries and veins and then were euthanatized and necropsied at various postsurgical times. tin 2 of the turkeys, infarction of pectoral and supracoracoid muscles was produced. Gross and microscopic examinations of these infarcts revealed that they were very similar to the lesions of deep pectoral myopathy.

Animals↗
PubMed1976

myo-Inositol metabolism in the neonatal and developing rat fed a myo-inositol-free diet.

Neonatal rats of the Holtzman strain, 6 days of age, were fed a myo-inositol restricted liquid formula by gastric intubation for 10 days, after which they were fed a purified myo-inositol-free diet until they were 72 days old. No differences in weight gain were observed between myo-inositol/100 ml of formula or 150 mg myo-inositol/100 g diet. Most tissues examined from rats fed the myo-inositol deprived formula and diet had lower free myo-inositol levels than the controls with the exception of the liver. Despite reduced free and lipid-bound myo-inositol in the liver, there was no evidence of fatty liver in the young rats at any age. The cerebrum and cerebellum of myo-inositol deprived rats had normal myelination and mitochondriogenesis as judged by the levels of 2',3'-cyclic nucleotide-3'-phosphohydrolase (EC 3.1.4.1) and fumarase (EC 4.2.1.2) activity, respectively.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗