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Biomedical subjects

T Umeda

Publications and source records attributed to T Umeda.

At least 361 records · Page 20Linked to original sources
PubMed1978

Effects of anesthetics on diphenylhydantoin metabolism in the rat: possible inhibition by diethyl ether.

The effects of diethyl ether and urethane on the elimination of diphenylhydantoin (DPH) in the rat were compared. The apparent half-life of DPH following a dose of 10 mg/kg, iv, under continuous ether anesthesia was 284 +/- 47 min, while the half-life under urethane anesthesia was 25.5 +/- 6.3 min. The latter was in agreement with the literature value for DPH half-life without anesthesia. The effects of both anesthetic agents on bile flow and indocyanine green clearance were not different. Following intravenous administration of DPH (1 mg/kg), DPH metabolites excreted in bile at 2 h were 75.3 +/- 4.8% of the dose with urethane anesthesia and 25.0 +/- 5.0% of the dose with continuous ether anesthesia. The data suggest that ether may inhibit the DPH metabolism in vivo, most likely at the hydroxylation step, while urethane does not.

Anesthetics↗
PubMed1978

Echocardiographic evaluation of left ventricular filling in mitral stenosis. Role of atrial contraction.

Echocardiographic evaluation of left ventricular volume change during rapid and atrial filling periods was made in patients with mital stenosis. The significant reduction of rapid filling volume was observed and the rate of rapid filling was approximately the half of normal in mitral stenosis. The rapid filling period showed a good correlation to the mitral valve area measured at operation. After surgical treatment, the rate of rapid filling was significantly increased but was still significantly smaller than normal. It was suggested that the remained structural abnormality of mitral apparatus depressed the inflow through the mitral valve in early diastole despite successful mitral valvotomy. Left ventricular filling during atrial contraction (atrial filling) was augmented twice as much as normal in patients with milder mitral stenosis, compensating the decreased early diastolic filling. In contrast, the atrial filling did not increase in severe mitral stenosis, resulting in the decreased cardiac output. Following mitral commissurotomy, the atrial filling in milder mitral stenosis was reduced but remained significantly larger than normal. There was no change of atrial filling in severe mitral stenosis postoperatively. This fact suggested the existence of impaired contraction of left atrium in cases with severe mitral stenosis. Our results show that the altered left atrial transport function plays an important role in the left ventricular filling in mitral stenosis.

Adult↗
PubMed1977

Echocardiographic left ventricular volume determination by direct measurements of the major and minor axes.

Major and minor axes of the left ventricle were measured by single beam echocardiography in ten cardiac patients and the measurements and calculated volumes by formula V=pi/6 D2 were compared with the angiocardiographic estimates. There was a favorable correlation between echocardiographic and angiocardiographic major axis dimention (r=0.79), left end-diastolic volume (r=0.96), and ejection fraction (r=0.81). On the contrary, left end-diastolic volume calculated by formula V=D3 was less correlated with angiocardiographic estimates (r=0.93) and the former had a tendency to overestimate the volumes where D exceeded 6.5 cm. These data indicate that in cases with markedly enlarged left ventricle, the use of formula V=pi/6 D2L is a more accurate predictor of volumes than formula V=D3.

Adult↗