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Biomedical subjects

J R Coffman

Publications and source records attributed to J R Coffman.

At least 19 recordsLinked to original sources
PubMed1992

Pulmonary artery and aortic pressure changes during high intensity treadmill exercise in the horse: effect of frusemide and phentolamine.

Intravenous frusemide (1.0 mg/kg bwt) or phentolamine (0.33 mg/kg bwt) was given to 7 horses 1 h before exercise and their effects on pulmonary artery and aortic pressure changes during strenuous exercise were examined. Short-term near-maximal treadmill exercise (10 m/sec, 3 degrees incline) produced increases in heart rate, mean pulmonary artery pressure (PAP), mean aortic pressure (AP), and packed cell volume (PCV). Frusemide did not affect heart rate, PAP or PCV during exercise. Frusemide significantly decreased mean AP by 10 to 15 mmHg during exercise. Phentolamine produced an increase in heart rate relative to control only early in exercise but not during later, more strenuous, exercise. Phentolamine had no statistically significant effect on AP, PAP, or PCV, but a significant reduction was observed between 180 and 230 sec of exercise when PAP and AP were standardised against heart rate. Frusemide did not prevent horses from haemorrhaging during exercise in this study. Treatment with phentolamine did not sufficiently reduce the PAP and AP to test our hypothesis that a reduction in PAP and AP would eliminate EIPH.

Animals↗
PubMed1990

Pulmonary artery, aortic and oesophageal pressure changes during high intensity treadmill exercise in the horse: a possible relation to exercise-induced pulmonary haemorrhage.

This study investigated changes in packed cell volume (PCV), pulmonary artery and aortic pressures, and the interaction between oesophageal pressure and pulmonary artery and aortic pressures during strenuous exercise in the horse. It was hypothesised that oesophageal pressure changes summate with pulmonary artery and aortic pressures during exercise and contribute to exercise-induced pulmonary haemorrhage (EIPH). Acute treadmill exercise (10 m/sec, 3 degrees incline) produced increases in heart rate (HR) from 50 to 202 beats/min; mean pulmonary artery pressure (PAP) from 28 to 80 mmHg; mean aortic pressure (AP) from 108 to 157 mmHg; and PCV from 0.35 to 0.52 litres/litre. EIPH was observed in three of seven horses after treadmill exercise, but no differences in the above variables were observed between the two groups of horses. Electronic subtraction of the oesophageal pressure signal from PAP and AP signals indicated peak transmural pressures of approximately 150 mmHg pulmonary and 175 mmHg aortic pressure. The elevated PAP associated with exercise appeared related more to increased HR and less to PCV (blood viscosity) or AP (bronchial). Both pulmonary artery and aortic peak transmural vascular pressures were substantially influenced by oesophageal pressure changes; peak and mean pulmonary artery and aortic pressures were significantly higher than resting pressures, and may conceivably contribute to EIPH.

Animals↗
PubMed1984

Ulcerative colitis and protein losing enteropathy associated with intestinal salmonellosis and histoplasmosis in a horse.

Ulcerative colitis, protein losing enteropathy and intestinal histoplasmosis-salmonellosis were diagnosed in a six-year-old Quarterhorse stallion. For six months before examination, the horse experienced a slow continual loss of weight. During the 17 day period of hospitalisation the horse developed progressive generalised oedema. On the 12th day of hospitalisation a severe profuse watery diarrhoea began; the horse was killed five days later.

Animals↗
PubMed1983

Insulin tolerance in laminitic ponies.

Sensitivity to insulin was assessed in ponies episodically affected with chronic laminitis by measurement of blood glucose and arterial blood pressure during insulin tolerance tests. In terms of blood glucose values, laminitic ponies were significantly less sensitive to insulin than controls. Conversely, a post-insulin decline in diastolic, systolic and mean blood pressure values was significantly greater in laminitic ponies than in controls.

Animals↗
PubMed1981

Haematological changes during development of acute laminitis hypertension.

Experimental carbohydrate overload of 15 horses resulted in consistent haematological changes during development of laminitis hypertension. Significant alterations in packed cell volume, leucocyte differential count, serum glucose levels and protein values occurred before onset of Obel grade 3 lameness and hyperkinetic circulatory state. Blood platelets were significantly decreased 8 h after the onset of severe lameness. Findings in this study were indicative of haemoconcentration due to compartmental fluid shifts and leucocytic stress response consistent with increased circulating adrenoglucocorticoids and/or catecholamines.

Acute Disease↗
PubMed1979

Orgotein in equine navicular disease: a double blind study.

Fourteen horses (7 treated with orgotein and 7 treated with a placebo) with navicular disease were studied on a double blind basis. All 14 horses had clinical and radiographic evidence of navicular disease. Orgotein and the placebo were administered by juxtabursal injection. Of the 7 orgotein-treated horses, 3 responded but none of the 7 placebo-treated horses responded. The difference was statistically significant (P less than 0.05).

Animals↗
PubMed1977

Epidural melanoma causing posterior paresis in a horse.

An aged gray stallion was examined because of fullminating posterior paresis, bladder paralysis, and perineal anesthesia. Lower motor neuron dysfunction was detected at the lumbosacral level of the spinal cord, and cerebrospinal fluid was yellow. After brief supportive treatment, the horse died. Necropsy revealed a single epidural melanoma at L5-6. The absence of cutaneous melanotic growth, absence of organ involvement, and extensive vertebral remodeling indicated the neoplasm to have been primary and to have been present for an extended period. Neurologic dysfunction was acute and progressive, as a result of spinal cord compression by the neoplasm.

Animals↗
PubMed1977

Cardiac output, left ventricular ejection rate, plasma volume, and heart rate changes in equine laminitis-hypertension.

Acute laminitis-hypertension was produced experimentally by carbohydrate overloading of the gastrointestinal tract in 8 horses, and the resulting hemodynamic changes were measured. Statistically significant (P less than 0.01) increases in cardiac output, left ventricular ejection rate, heart rate, and arterial pressure were related to statistically nonsignificant changes in peripheral resistance and a delayed (Obel grade 3 plus 24 hours) decrease in plasma volume. When compared with control values, the doubling of cardiac output and left ventricular ejection rate simultaneous with little or no change in either peripheral resistance or plasma volume (16 hours after the occurrence of Obel grade 3 lameness) was suggestive of an increase in myocardial contractility. Because these pathophysiologic phenomena have important time relationships to the onset of Obel grade 3 lameness in acute laminitis, the results of this investigation are discussed in light of their relationship to clinical signs, serum electrolyte changes, plasma L-lactate alterations, and histologic deterioration of the digit.

Animals↗