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Biomedical subjects

R Aamodt

Publications and source records attributed to R Aamodt.

24 records · Page 2Linked to original sources

Acute coronary occlusion: prolonged increase in collateral flow following brief administration of nitroglycerin and methoxamine.

Regional coronary blood flow was determined with the radioactive microsphere technique 10 an 70 minutes and 2 1/2 and 5 hours after abrupt occlusion of the left anterior descending coronary artery in 12 closed chest sedated dogs. In six dogs, nitroglycerin, 200 to 400 microng/min, was infused intravenously 10 to 70 minutes after occlusion. Methoxamine was administered to return blood pressure and heart rate to prenitroglycerin levels. Ten minutes after occlusion (before treatment) collateral flow values and ischemic zone endocardial/epicardial flow ratios were equivalent in untreated (0.11+/-0.03 ml/min per g; 0.31+/-0.05) and treated dogs (0.14+/-0.02 ml/min per g; 0.29+/-0.03). In untreated dogs, collateral flow did not change over 5 hours; the endocardial/epicardial flow ratio was decreased at 5 hours (0.21+/-0.05, P less than 0.05). In contrast, in treated dogs, collateral flow and the endocardial/epicardial flow ratio were increased at 70 minutes (0.27+/-0.04 ml/min per g, P less than 0.05; 0.53+/-0.10, P less than 0.05). Most importantly, collateral flow remained elevated 5 hours after occlusion (0.26+/-0.03 ml/min per g, P less than 0.05) although treatment was discontinued 70 minutes after occlusion. Hence, collateral flow was unchanged over 5 hours of occlusion in untreated dogs, but short-term treatment with nitroglycerin and methoxamine resulted in a sustained increase in collateral flow. These findings may be a result of stimulation by nitroglycerin and methoxamine of the spontaneous rate at which intrinsic collateral function increases after ischemia. Alternatively, nitroglycerin and methoxamine may maintain cell viability until collateral vessels develop spontaneously.

Animals↗

Kinky hair disease. Study of copper metabolism with use of 67Cu.

Metabolism of labeled Cu (67Cu) was studied in three patients with kinky hair disease (KHD). Labeled Cu was administered first intravenously and, later, orally. We determined oral absorption, excretion, and internal kinetics of this metal. Patients with KHD absorbed 11% to 13% of Cu given orally, compared to 46% by unaffected controls. Total excretion of Cu given intravenously during the first seven days after administration was greatly reduced in patients with KHD. The biological half-life of 67Cu in patients with KHD was increased by a factor of 2 to 3 over the normal control. Most of the labeled Cu was retained by the patient's liver, while in the control subject there was more rapid movement to the Cu to circulation (ceruloplasmin). Red blood cells of patients with KHD incorporated orally administered Cu preferentially, which was sufficient to prevent anemia.

Age Factors↗

Body cell mass in cancer-bearing and anorexic patients.

We used a sensitive whole body counter which measures potassium-40 (40K) to determine total body potassium and to estimate body cell mass (BCM) in 104 previously untreated patients with upper gastrointestinal malignancies, 233 normal volunteers, and 18 patients with anorexia nervosa. BCM was greater in normal males than in females. In both normal males and females, the BCM tended to decrease with age, both as an absolute measure and as a percentage of body weight. Anorexia nervosa patients experienced marked weight loss (30.5%), and had significant depletion of absolute BCM, but exhibited relative sparing of BCM as indicated by a rise in BCM as a percentage of body weight. This may reflect a normal adaptation and predominant fat utilization in chronic malnutrition. The cancer patients, on the other hand, had significant weight loss (12.7% for females, 13.9% for males) and demonstrated a proportional decline in BCM, with no change in BCM as a percentage of body weight. These findings support the contention that, in the cancer-bearing patient, weight loss consists of a significant depletion of both fat and BCM. The challenge to the clinicians caring for cancer patients is repletion of this supremely functional body compartment.

Adult↗