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Biomedical subjects

M Usami

Publications and source records attributed to M Usami.

At least 307 records · Page 17Linked to original sources
PubMed1979

Exercise stress myocardial perfusion scintigraphy with thallium-201.

We performed exercise stress scintigraphy with thallium-201 in 88 patients including 31 patients of effort angina and nine patients of old myocardial infarction without angina. Sensitivity of exercise stress scintigraphy to detect effort angina was 77%, whereas sensitivity of exercise stress ECG was only 44.5%. The combination of stress scintigraphy with stress ECG enhanced sensitivity up to 87%. Exercise stress scintigraphy was useful particularly in cases with one vessel disease and those who failed to achieve sufficient exercise stress. Besides exercise stress scintigraphy did not show false positive response, differing from exercise stress ECG. Myocardial imaging is a method which shows the balance between myocardial perfusion demand and supply.

Adult↗
PubMed1978

Inactivation of phosphorylase phosphatase by a factor from rabbit liver and its chemical characterization as glutathione disulfide.

A factor inactivating phosphorylase phosphatase was isolated from rabbit liver. The isolation procedure consisted of heat treatment at 85 degrees C, extraction with n-butyl alcohol, and chromatography on Dowex 1 and DEAE-cellulose columns. The purified factor was different from the known protein inhibitors and was shown to be tripeptide composed of equimolar amounts of glutamic acid, cysteine, and glycine. The NH2-terminal and COOH-terminal amino acids were determined as glutamic acid and glycine, respectively. The factor was finally identified as glutathione disulfide by high voltage paper electrophoresis, paper chromatography, and liquid column chromatography using an amino acid analyzer. Addition of the purified factor or glutathione disulfide converted phosphorylase phosphatase to a stable, less active enzyme species, the extent of conversion depending on the amount added. The inactivated phosphatase was completely reactivated by addition of both glutathione (or 2-mercaptoethanol) and Mn2+ and partially reactivated by adding glutathione alone. Injection of glutathione disulfide into the portal vein of rabbits caused a rapid increase in phosphorylase alpha activity in the liver. These results suggest that glutathione disulfide is involved in regulation of phosphorylase activity in vivo, by causing inactivation of phosphorylase phosphatase in the liver.

Animals↗
PubMed1977

Studies on fatty acid omega-oxidation. Antiketogenic effect and gluconeogenicity of dicarboxylic acids.

1. Administration of dicarboxylic acids to starving rats decreased the concentration of ketone bodies in the blood. 2. Incorporation of 14C into blood glucose was greater from dicarboxylic acids than from monocarboxylic acids. 3. These results suggest that omega-oxidation may be important for production of succinyl-CoA from fatty acids. 4. In starving or diabetic rats about 15% of palmitic acid were subjected to omega-oxidation and then beta-oxidation.

Animals↗