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Biomedical subjects

M Tahara

Publications and source records attributed to M Tahara.

107 records · Page 6Linked to original sources
PubMed1982

Interchangeability of delta subunits of RNA polymerase from different species of the genus Bacillus.

RNA polymerase was purified from five species of Bacillus, including Bacillus subtilis. Each polymerase had a subunit composition analogous to that reported for B. subtilis, i.e., beta beta '2 alpha sigma delta omega 1 omega 2. The delta subunits from the B. subtilis and Bacillus thuringiensis polymerases were interchangeable, as judged from their effects on promoter selection in the polymerase binding assay.

Bacillus↗
PubMed1981

Hemodynamic determinants of pulmonary valve motion during systole in experimental pulmonary hypertension.

To clarify the determinants of pulmonary valve (PV) motion in pulmonary hypertension, we examined the correlations among PV echo patterns, the pulmonary artery (PA) flow curve just above the PA orifice and the pulmonary artery-right ventricle (PA-RV) pressure gradient. By constricting the PA, we could produce a variety of PV echo patterns, including midsystolic semiclosure in open-chest dogs. Throughout the experiments, the PV echo pattern and PA flow curve were similar in pattern and timing. When the PV echo showed midsystolic semiclosure with reopening. The PA flow curve showed a transient decrease followed by a transient increase during midsystole. The PA-RV pressure gradient became transiently positive (PA pressure greater than RV pressure) and then negative in midsystole only when the PV echo showed midsystolic semiclosure with reopening. In conclusion, PV motion during systole may be instantaneously determined by PA flow change and the PA-RV pressure gradient during the cardiac cycle in experimental pulmonary hypertension.

Animals↗
PubMed1980

Diastolic bulging of the interventricular septum toward the left ventricle. An echocardiographic manifestation of negative interventricular pressure gradient between left and right ventricles during diastole.

Diastolic bulging of the interventricular septum (IVS) toward the left ventricle was observed by real-time cross-sectional echocardiography in three patients with primary pulmonary hypertension and one patient with secondary pulmonary hypertension after closure of an atrial septal defect. M-mode echocardiography showed a characteristic abnormal pattern of septal motion in diastole and in systole. In two patients, we attempted to correlate M-mode motion to the interventricular pressure gradient. During diastole, the interventricular pressure gradient between the left and right ventricles was negative and the pressure gradient curve was very similar to the M-mode echogram of the IVS. Banding studies in which acute right ventricular hypertension was produced in dogs showed similar shape changes, suggesting that the diastolic shape and motion of the septum are determined by the interventricular pressure gradient between the ventricles. Diastolic bulging of the IVS toward the left ventricle in our patients results from negative interventricular pressure gradient between the left and right ventricles during diastole.

Adult↗