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Biomedical subjects

R D Tyler

Publications and source records attributed to R D Tyler.

At least 37 records · Page 2Linked to original sources

Ehrlichiosis and polyarthritis in three dogs.

Three dogs admitted for evaluation of lameness were determined to be infected with a neutrophilic strain of Ehrlichia. Ehrlichia morulae were detected in low numbers in both synovial fluid and blood neutrophils. The dogs had rapid clinical improvement after appropriate antibiotic therapy. A diagnosis of canine ehrlichiosis easily could have been missed if morulae had not been identified. Ehrlichiosis should be considered in acutely lame dogs residing in areas enzootic for ehrlichiosis. A careful search for Ehrlichia morulae within synovial fluid and blood neutrophils should be performed. An E canis titer determination also may be helpful.

Animals↗

Identification of Histoplasma organisms in circulating eosinophils of a dog.

Disseminated histoplasmosis was diagnosed in a 10-year-old dog that had chronic diarrhea, weight loss, fever, and anemia. The diagnosis was based on detection of Histoplasma organisms in circulating neutrophils, monocytes, and eosinophils. The dog had severe histoplasmal fungemia, which may have been caused by treatment with prednisolone.

Animals↗

Detection of anticytauxzoon antibodies in cats infected with a Cytauxzoon organism from bobcats.

A microfluorometric immunoassay was developed for the detection of antibodies to a Cytauxzoon organism of bobcat origin. A homogenated antigen of RBC-parasite lysate was used to measure antibody levels in sera from cats experimentally infected with the non-pathogenic erythrocyte form of the bobcat Cytauxzoon organism. Antibody levels in sera collected at weekly intervals, expressed as FIAX values, were correlated with parasitemia levels and erythrocyte packed cell volume (PCV). The antibody levels tended to be highest and the PCV lowest at or near the peak parasitemias. Splenectomized cats developed higher antibody and parasitemia levels than non-splenectomized cats. Single serum samples collected from 31 cats were used to establish a baseline response level for normal domestic cat populations.

Animals↗

Experimental chloramphenicol intoxication in neonatal calves: intravenous administration.

Chloramphenicol was administered intravenously for eight to 17 days to five newborn calves at a daily dosage of 100 mg kg-1. Haemodynamic, haematological, blood chemistry, serum enzyme, urinalysis and clinical responses were evaluated. High levels of serum chloramphenicol were observed throughout the study although a marked increase in elimination rate was seen with increasing age. The most severe adverse effects were severe hypotension following rapid intravenous administration and severe gastrointestinal dysfunction with diarrhoea accompanying prolonged high dosage. There appeared to have been a haematological effect in one calf, but it was of minor significance compared with the other effects.

Animals↗

Renal concentrating ability in dehydrated hyponatremic dogs.

Eleven hyponatremic dogs were unable to concentrate their urine during periods of severe dehydration and azotemia. When normonatremia was reestablished in eight of the dogs, their renal concentrating ability returned. Six dogs, including the 3 dogs in which normonatremia was not reestablished, died or were euthanatized; renal lesions were not found during postmortem examination. Two dogs had hypoadrenocorticism, which has been documented as a cause of hyponatremia and impaired renal concentrating ability. Two dogs had gastrointestinal disease, which has been documented as a cause of hyponatremia, but not of impairment of renal concentrating ability. All dogs without hypoadrenocorticism had clinical and clinicopathologic indications of blood loss, which has not been documented as a cause of hyponatremia or impairment of renal concentrating ability. Hyponatremia (less than 120 mEq/L) was induced by chronic blood removal in a dog maintained on a low-sodium diet. During the period of hyponatremia, the dog became azotemic, hypotensive, and severely dehydrated; renal concentrating ability was impaired. We conclude that hyponatremia may be caused by hemorrhage, but irrespective of the cause, hyponatremia impairs renal concentrating ability.

Adrenal Cortex Diseases↗

Disseminated histoplasmosis in cats: 12 cases (1981-1986).

Anemia, weight loss, lethargy, fever, anorexia, and interstitial lung disease were the predominant clinical findings in 12 cats with disseminated histoplasmosis. Some cats were examined because of dysfunction or lesions of bone, eyes, or skin. In most cases, the clinical signs were observed by the owner for 4 weeks or less before seeking veterinary care. Young cats were most commonly affected, with 7 of the 12 cats less than or equal to 1 year old. Identification of Histoplasma organisms in bone marrow aspirates was used to confirm the diagnosis of histoplasmosis in 11 of the 12 cats. Histoplasma infection of multiple organs was found at necropsy. In this study, disseminated histoplasmosis had a higher prevalence in cats than in dogs at the same veterinary medical teaching hospital. Feline disseminated histoplasmosis was not associated with FeLV infection. Treatment was attempted in 7 of the 12 cats.

Animals↗

Hematologic values in horses and interpretation of hematologic data.

Normal reference ranges and pertinent background information on equine hematology are presented and briefly discussed. Diagnostic interpretation of hematologic data is discussed and three diagnostic algorithms and two diagnostic tables are provided to facilitate the use of the presented information for diagnosis. Two cases are presented and the information presented in the article is used to interpret the case data.

Animals↗

Collection and evaluation of equine peritoneal and pleural effusions.

This article discusses collection, slide preparation, culture technique, fluid analysis and evaluation, and cytologic evaluation of peritoneal and pleural effusions. The morphologic characteristics of various effusions are described, and the physical characteristics (volume, color, turbidity) of effusions are discussed. An algorithm for classifying effusions as transudates, modified transudates, or exudates is included, and each category is discussed.

Animals↗

Changing manifestations of a chronic feline haematopoietic proliferative disease during immunotherapy with staphylococcal protein A.

A cat with feline leukaemia virus-associated malignant disease was treated by ex vivo immunoadsorption using staphylococcal protein A coated filters. During the 12-week course of treatment, the morphological manifestations of the haematopoietic disease showed a progressive transition from erythroid to myeloerythroid to myeloid predominance, and the disease was preceded by and associated initially and terminally with a blast transformation of lymphoblastic morphology. Necropsy revealed massive meningo-cerebral, as well as hepatic, renal, myeloid, lymphoid, peritoneal and pelvic infiltrations largely consisting of lymphoblastic cells. Evidence of myeloid and erythroid differentiation was present in all the infiltrates. The several possible bases for this shift of morphological expression are considered.

Animals↗

Renal function and fractional clearances of American river otters (Lutra canadensis).

The finely lobulated kidneys of American river otters (Lutra canadensis) are not visualized on plain abdominal radiographs. Similar values for blood urea nitrogen (BUN), creatinine, and uric acid were obtained on different analytical systems used in 1984 and 1985. The mean +/- SD for measured plasma osmolalities (309.80 +/- 8.86 mOsmol/kg) of otters in 1985 was significantly (P less than 0.01) less than that of calculated serum osmolalities in the same 1985 specimens (321.61 +/- 5.64 mOsmol/kg) and in 1984 specimens (322.20 +/- 7.16 mOsmol/kg). Urine specific gravities and osmolalities were highly correlated (r = 0.92). On routine urinalysis, protein and bilirubin were frequent chemical findings, and urobilinogen was present in all urine samples. White and red blood cells and epithelial cells were frequent findings on urine microscopic examinations. Proteus mirabilis was cultured from four of four female otters with genitourinary infections. The mean +/- SD creatinine values for paired serum and urine samples (n = 13) were serum creatinine (Scr) 0.66 +/- 0.09 mg/dl and urine creatinine (Ucr) 186.9 +/- 55.6 mg/dl. Corresponding values for serum electrolytes (Se) and urine electrolytes (Ue) yielded mean +/- SD calculated renal fractional clearances (FC = Ue/Se x Scr/Ucr) of sodium 9.65 +/- 5.81 x 10(-4), potassium 4.15 +/- 2.01 x 10(-2), chloride 10.81 +/- 5.33 x 10(-4), calcium 4.52 +/- 4.46 x 10(-3), and phosphate 6.58 +/- 3.44 x 10(-3).

Animals↗

Hypercalcemia in cats with feline-leukemia-virus-associated leukemia-lymphoma.

Three cases of hypercalcemia were recognized among 11 cats presenting with leukemia-lymphoma for ex vivo immunoadsorption therapy using Staphylococcal Protein-A-coated filters. In addition, the initial mean serum calcium concentration of cats with leukemia-lymphoma was significantly higher (P less than 0.005) than that of healthy control cats or feline-leukemia-virus-infected cats without malignancy. During immunotherapy of the hypercalcemic cats, objective reduction in the extent of the malignancies was associated with a small reduction in the serum calcium concentrations. This response to treatment, the lack of skeletal metastasis, and the absence of renal and parathyroid pathologic findings imply that humorally mediated mechanisms may have been responsible for the production of the hypercalcemia.

Animals↗

Clinicopathologic responses in cats with feline leukemia virus-associated leukemia-lymphoma treated with staphylococcal protein A.

Purified protein A from Staphylococcus aureus Cowan I was injected intraperitoneally or was incorporated in filters ex vivo through which plasma from cats with feline leukemia virus (FeLV)-associated leukemia-lymphoma was passed. Before treatment, 65% of the FeLV-infected cats were anemic, and 70% were thrombocytopenic. Concomitant infections, or immune-mediated disease, was common. During treatment 50% of the cats with FeLV-associated disease improved objectively with normal posttreatment hematocrits, thrombocyte and leukocyte counts, disappearance of dysplastic hematologic elements, and correction of marrow dyscrasias. A 33% response to treatment occurred in cats with unequivocal manifestations of malignant disease and was characterized by reductions in tumor size and marrow and peripheral blood neoplastic cell populations. Clearance of FeLV viremia was documented in 28% of the treated cats. The several possible mechanisms by which treatment with staphylococcal protein A causes reduction in the extent of malignant disease are considered.

Animals↗

Chloramphenicol and the neonatal calf.

Pharmacokinetic values and possible toxic effects of chloramphenicol on bone marrow and hematologic and serum chemical values were determined in newborn calves given the drug (IV) once a week or in repeated doses, 12 hours between doses. The rates of elimination for chloramphenicol and antipyrine also were compared. Chloramphenicol also was administered to older calves by IM and subcutaneous routes, with an apparent bioavailability of 50% to 60%. The elimination half-lives for both chloramphenicol and antipyrine were markedly increased in the newborn calf for at least the first 3 to 4 weeks of life. Despite the high and prolonged serum chloramphenicol concentrations in these calves, there was little or no indication of toxic effects. Bone marrow aspirates did not reveal any signs of intoxication such as cytoplasmic or nuclear vacuolation. Marrow cellularity was not recognizably different from the control group.

Age Factors↗

Peroxisome proliferator-activated receptors in atherosclerosis and inflammation--an update.

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor subfamily of transcription factors with pleiotropic effects on intra- and extracellular lipid metabolism, glucose homeostasis, cell proliferation, control of inflammation, and atherosclerosis. Three PPARs, namely alpha, delta, and gamma have been identified with distinct tissue distribution patterns and metabolic functions. PPAR-alpha is predominantly expressed in brown adipose tissue, liver, kidney, duodenum, heart, skeletal muscle, and vascular endothelial cells and is involved in the control of lipoprotein metabolism, fatty acid oxidation, and the cellular uptake of fatty acids. PPAR-gamma is highly expressed in brown and white adipose tissues and, to lesser extent, in large intestine, retina, and some parts of the immune system, and plays a critical role in adipocyte differentiation and fat deposition. PPAR-delta shows a widespread tissue distribution but its regulation and functions are not yet known. Considerable evidence indicates that PPARs (PPAR-alpha and PPAR-gamma) have beneficial effects in inflammatory diseases, including atherosclerosis, through regulation of cytokine production, adhesion molecule expression on the endothelial cells, fibrinolysis, and modulation of monocyte-derived macrophages. In this review, the general and specific roles of the PPAR isotypes and their implications in the control of vascular inflammation and atherosclerosis are discussed.

Adipose Tissue, Brown↗

From QA to TQM.

In the decade from 1950 to 1960, two quality-related processes--medical audit and total quality management--were being developed, one directly in the health care field and the other in the manufacturing sector. These processes remained isolated from each other until the mid-1980s. Each would have a separate but major effect on the health care industry.

Data Collection↗

Quality assurance in the ambulatory care setting.

One of the most utilitarian developments in the field of quality assurance in health care has been the introduction of industrial concepts of quality management. These concepts, coupled with buyer demand for accountability, are bringing new perspectives to health care quality assurance. These perspectives provide a new view of quality assurance as a major responsibility and strategic opportunity for management; a competitive and marketable commodity; and a method of improving safety, effectiveness, and satisfaction with medical care.

Ambulatory Care Facilities↗

In wap-ras transgenic mice, tumor phenotype but not cyclophosphamide-sensitivity is affected by genetic background.

Male wap-ras transgenic mice develop adenocarcinomas in salivary and/or mammary tissue by age 1 year. When the wap-ras transgene was bred into the FVB/N strain, males developed multiple mammary tumors between 1.5 and 3 mo. of age, but no salivary tumors. Crosses between ras/FVB mice and other strains produced moderate changes in mammary tumor onset and severity, but no salivary tumors. Histopathological analysis of 62 adenocarcinomas from 18 mice yielded: 14 tumors with areas of squamous metaplasia, many tumors with epithelium-lined cysts, few immune cells in tumors, and no lung metastases. Cyclophosphamide delayed tumor onset and inhibited the growth of established tumors. Our results suggest that wap-ras mice will be useful for studying ras-mediated tumor genetics and should be a good assay system for both preventative and curative anticancer therapies.

Adenocarcinoma↗