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Biomedical subjects

S Asada

Publications and source records attributed to S Asada.

At least 73 records · Page 4Linked to original sources
PubMed1989

[Application of multi-lines fitting technic for ethenzamide elimination with capacity-limited process in the rabbit plasma].

Intravenous and oral administrations of ethenzamide (EZ) were carried out in the rabbit, and elimination process pharmokinetically discussed. When the drug dose increased, plasma clearance and extent of bioavailability were reduced and plasma peak times delayed after oral dose of EZ. Michaelis-Menten type elimination parameters were estimated from the plasma concentration-time profiles after intravenous dosing of EZ. The first-order absorption rate constant (ka), hepatic available fraction (FH) and approximate elimination rate constant (K) for hepatic first-pass metabolism of EZ were estimated using computer multi-lines fitting technique by iterative nonlinear least squares regression program, MULTI (RUNGE).

Animals↗
PubMed1989

A study on gastric ulcers induced by long-term fasting in rats.

The present study was performed to investigate the roles of intragastric pH and PAS positive mucus as to the incidence of gastric ulcers after long-term fasting in rats. Gastric ulcers in the forestomach and corpus were found at 4 and 6 days after fasting, respectively. The intragastric pH was significantly reduced at 1, 2, 3, 4, 6 and 7 days after fasting, but tended to have returned to control levels at 8 days. PAS positive mucus was significantly increased at 2 to 7 days, but there was no significant change at 8 days. From these results, it seems that the aggressive factor is not involved, but attenuation of the defensive factor is important as to the incidence of this type of ulcer. As one of the causes of this attenuation, a decrease in the gastric mucus volume was suggested.

Animals↗
PubMed1989

[A case of hepatocellular carcinoma (HCC) with a huge tumor thrombus in the right atrium].

A case of HCC with a huge tumor thrombus in the right atrium is reported. CT and celiac angiography revealed HCC in the liver. Inferior vena cavography and cardiac blood pool scintigraphy demonstrated a large defect in the right atrium, and 67Ga-citrate scintigraphy showed a lesion of abnormal accumulation in the right atrium. With these findings, diagnosis of HCC with a tumor thrombus in the right atrium was made, and the clinical diagnosis was confirmed by autopsy.

Carcinoma, Hepatocellular↗
PubMed1989

[Serial myocardial lactate metabolic changes after intracoronary thrombolysis in evolving myocardial infarction].

To ascertain whether early intracoronary reperfusion (less than 3 hours) preserves aerobic myocardial metabolism in acute myocardial infarction, serial changes in trans-cardiac lactate extraction after intracoronary thrombolysis were examined in 35 patients with acute anteroseptal myocardial infarction. Eight patients without intracoronary reperfusion served as controls. In the chronic phase, we also observed abnormally contracting myocardial segments as an index of infarct size and the regional ejection fraction as an index of chronic regional cardiac function. In the early reperfusion group (less than 3 hours; 15 cases), positive lactate extraction was restored; there were small abnormally-contracting segments and a high regional ejection fraction. However, the intermediate reperfusion group (3-5 hours; 10 cases) had sustained anaerobic lactate extraction, large abnormally-contracting segments and a low regional ejection fraction. The late reperfusion (greater than 5 hours; 10 cases) group showed apparent aerobic lactate extraction, but had large abnormally-contracting segments and a low regional ejection fraction. Thus, early reperfusion preserves aerobic lactate metabolism and good ventricular function in the chronic phase.

Heart Ventricles↗
PubMed1988

[Healing promoting effect of proamipide, a novel drug that increases gastric defense mechanisms, on acetic acid-induced gastric ulcers in the rat].

The healing process of acetic acid-induced gastric ulcers was studied for over 180 days after ulcerogen injection, and the effect of a new antiulcer agent, proamipide, was also assessed by histological measurements. In the control group, rapid reduction in the macroscopic ulcer index and increment in histological indices such as healing, regeneration of defective mucosa and proliferation of granulation tissue were observed from the 5th day to the 60th day after the ulcer induction followed by significant aggravation on the 120th and 140th day, suggesting the recurrence or relapse of gastric ulcers may occur at about 120 to 140 days after acetic acid administration. Proamipide (20 mg/kg/day, p.o.) decreased all of these indices significantly from those in the control group. This indicates that proamipide remarkably promotes the healing process in acetic acid-induced gastric ulcers, the regeneration of the injured mucosa and also the formation of granulation tissue. The glandular index in the surrounding areas of the regenerated mucosa was lower than that in the central part in the control animals and this difference was decreased by proamipide intake, suggesting an imbalance in the regenerated mucosa of the scar may have significant roles in the induction of the recurrence or relapse of gastric ulcers.

Acetates↗
PubMed1986

[Collateral circulation during exercise-induced angina: evaluation by coronary angiography].

The pathophysiological significance of coronary collateral vessels remains controversial, despite previous intensive studies. We performed the multistage supine ergometer stress test for 26 patients with effort angina and collaterals. The changes in the collaterals were observed during each anginal attack by coronary angiography before and after intravenous nitroglycerin. The collaterals of 21 patients disappeared or diminished during exercise-induced angina before nitroglycerin administration, and were unchanged in the remaining five cases. However, the collaterals of all patients after nitroglycerin administration were unchanged or increased during exercise-induced angina. Considering there were no significant changes in pulmonary arterial end-diastolic pressures during angina before and after nitroglycerin administration, a pressure gradient between the donor and recipient coronary arteries was suggested as being related to the patency of the collaterals. These results suggested the following: 1. It is not appropriate to postulate that the collaterals visualized at rest may remain unchanged during exercise-induced angina. 2. It is not reasonable to conclude that exercise accelerates the development of collateral circulation. 3. One favorable effect of nitroglycerin administration is the prevention of exercise-induced ischemia via collateral circulation.

Adult↗
PubMed1986

[Pulmonary arterial end-diastolic pressure noninvasively estimated by continuous wave Doppler echocardiography].

To estimate pulmonary arterial end-diastolic pressures noninvasively, we measured the pulmonary regurgitant flow velocity by continuous wave Doppler echocardiography in 17 patients with pulmonary hypertension (pulmonary arterial end diastolic pressure greater than or equal to 18 mmHg) and in 23 patients without pulmonary hypertension. Pulmonary regurgitation was successfully detected by continuous wave Doppler echocardiography in 14 of the 17 patients with pulmonary hypertension and in 14 of the 23 patients without pulmonary hypertension. The end-diastolic pulmonary artery-to-right ventricular pressure gradient was estimated from the Doppler-determined pulmonary regurgitant flow velocity by means of a simplified Bernoulli equation. The Doppler-determined end-diastolic pulmonary artery-to-right ventricular pressure gradient correlated well with the catheter measurement (r = 0.94). It also correlated well with the pulmonary arterial end-diastolic pressure (r = 0.92). Thus, continuous wave Doppler echocardiography was useful in estimating noninvasively pulmonary arterial end-diastolic pressures.

Adolescent↗