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Biomedical subjects

A Ueda

Publications and source records attributed to A Ueda.

At least 199 records · Page 11Linked to original sources
PubMed1982

Argininosuccinate synthetase activity in cultured skin fibroblasts of citrullinemic patients.

The activities and kinetic properties of argininosuccinate synthetase in cultured skin fibroblasts of three citrullinemic patients with qualitative or quantitative abnormalities of hepatic argininosuccinate synthetase were examined. The cultured skin fibroblasts of a citrullinemic patient with a low hepatic argininosuccinate synthetase activity showed low activity and abnormal kinetics similar to those of the hepatic enzyme. This suggests a similar genetic origin of the fibroblast argininosuccinate synthetase as of the hepatic enzyme. However, we found normal argininosuccinate synthetase activity in cultured fibroblasts of two citrullinemic patients who had a low hepatic enzyme activity resulting from decrease in the amount of enzyme protein but with normal kinetic properties. This suggests that part of the quantitative abnormality of hepatic argininosuccinate synthetase of citrullinemic patients may be due to an abnormal organ-specific gene expression in the liver.

Adolescent↗
PubMed1981

Qualitative and quantitative abnormalities of argininosuccinate synthetase in citrullinemia.

Enzymological and immunochemical analyses of the liver were preformed in seven Japanese patients with citrullinemia. Among the urea cycle enzymes in the liver, only the activity of argininosuccinate synthetase was specifically decreased to 2 to 50% of normal controls. Liver argininosuccinate synthetase of patients was indistinguishable from that of controls when tested immunochemically by Ouchterlony's double immunodiffusion technique with anti-rat argininosuccinate synthetase antiserum. Immunochemical analysis by means of the single radial immunodiffusion revealed that the decrease in the activity of liver argininosuccinate synthetase was explainable by a decrease in the amount of the enzyme protein in five patients, while the decrease in the activity in the other two patients was not accompanied by a decrease of enzyme protein. The Km values for the substrates of liver argininosuccinate synthetase of the former five were similar to those of the control, while the kinetic properties of the latter two were quite different in terms of higher Km values and negative cooperativity. From these results, we consider that citrullinemia may consist of more than one type including qualitative or quantitative abnormalities of argininosuccinate synthetase caused by some defects in certain genes or in the epigenetic processes in the liver.

Adolescent↗
PubMed1981

Primary thrombocythemia and myocardial infarction in a 26-year-old woman with normal coronary arteriogram.

Acute myocardial infarction occurred in a 26-year-old woman with normal coronary arteriogram and primary thrombocythemia (500,000 approximately 1,500,000/mm3). Hyperaggregability of platelets was also demonstrated by stimulation with adenosine diphosphate, collagen, and epinephrine administration. A stillbirth at the 8th month of gestation in her past history was referred to the complication of primary thrombocythemia, too. Since discharge, the patient has been on 750 mg of aspirin and then free of any thromboembolic symptoms and signs, even during pregnancy and labour.

Adult↗
PubMed1980

Hemodynamic effects of nifedipine in congestive heart failure.

Nifedipine, a potent coronary vasodilator, was administered in a single sublingual dose of 20 mg to eight patients with mild to moderate congestive heart failure. Nifedipine produced a slight increase in heart rate (mean +/- standard error of the mean 73.3 +/- 3.2 versus 80.9 +/- 2.1 beats/min, p < 0.025) and an increase in cardiac index (from a control value of 3.51 +/- 0.22 to 4.06 +/- 0.31 liters/min per m2, p < 0.01). Arterial blood pressure decreased from 112.9 +/- 6.2/67.7 +/- 4.2 (mean 84.9 +/- 4.0) to 100.8 +/- 4.4/56.4 +/- 11.0 (mean 76.1 +/- 4.3) mm Hg (p < 0.01) and total systemic vascular resistance also decreased from a control value of 15.6 +/- 1.0 to 12.4 +/- 0.8 units (p < 0.01) after administration of nifedipine. These data suggest that nifedipine may be useful for vasodilation in congestive heart failure.

Adult↗
PubMed1980

Comparison of the urea cycle in conventional and germ-free mice.

The urea cycle in the liver of conventional mice was compared with that of germ-free mice. Among the urea cycle enzymes and urea cycle-related substances, only ornithine in the liver of the conventional mice was markedly more abundant than in that of the germ-free mice. The significance of this finding was supported by the comparison of the urea synthesis in the liver slices from these two types of mice.

Animals↗
PubMed1980

Effects of right and left ventricular pressure overload on left ventricular function and metabolism in dogs.

The effects of acute pressure overload of the right and left ventricle on the left ventricular hemodynamics, coronary circulation, and myocardial metabolism in dogs were investigated by banding of the main pulmonary artery and by producing two models of aortic constriction with (type B) and without (type A) aortocoronary bypass. Pulmonary artery banding (left ventricular preload reduction) showed right ventriculr systolic pressure (RVSP), right ventricular end-diastolic pressure (RVEDP), and right ventricular dP/dtmax significantly elevated, but left ventricular systolic pressure (LVSP), left ventricular (dP/dtmax)/IIP slightly decreased, contrary to a slight increase of left ventricular end-diastolic pressure (LVEDP). The blood flow of the left coronary circumflex artery (CBF) was slightly decreased, but the aortic blood flow (AoF) and left ventricular work per minute (LVW) were significantly reduced. As to myocardial metabolism, the coronary arteriovenous difference (delta) of carbohydrate, mainly glucose (G) and lactate (L), increased, while that of non-esterified fatty acid (NEFA) showed a significant reduction. Aortic coarctation (left ventricular afterload increase) showed, both in types A and B, left ventricular systolic pressure, left ventricular end-diastolic pressure, and left ventricular work per minute were increased. However, aortic systolic and diastolic pressure were significantly decreased. The blood flow of the left coronary circumflex artery tended to increase in both types. The myocardial carbohydrate uptake tended to increase after aortic constriction in both types. However, the uptake of non-esterified fatty acid was increased after aortic constriction in type A, but decreased in type B. This difference in uptake of non-esterified fatty acid might be induced by the difference of the functional state of the left ventricle.

Animals↗