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Biomedical subjects

M Takeuchi

Publications and source records attributed to M Takeuchi.

At least 919 records · Page 51Linked to original sources
PubMed1984

[Regional myocardial contraction in ischemic heart disease: evaluation of regional myocardial thickening by two-dimensional echocardiography].

There were many studies concerning the evaluation of regional wall motion in ischemic heart disease by left ventriculography (LVG) and two-dimensional echocardiography (2DE), but only a few observations on the regional myocardial thickening have been reported. In a survey of 48 cases of old myocardial infarction, we selected 21 cases with adequate 2DE images for the evaluation of regional wall motion and thickening. In all cases the 2DE examinations were performed within seven days before or after LVG examinations. The left ventricular wall on 2DE was divided into 11 segments and wall motion and thickening in each segment were graded to three classes, i.e. none, reduced and normal. The results on 2DE were then compared with the grade of wall motion of the corresponding segment on LVG. The sensitivity and specificity of 2DE wall motion were 50% and 89% in none, 59% and 48% in reduced, and 89% and 84% in normal, respectively. The sensitivity and specificity of 2DE myocardial thickening were 81% and 93% in none, 82% and 70% in reduced, and 92% in normal, respectively. These results indicated that the regional myocardial thickening by 2DE has a higher sensitivity and specificity. Therefore, observation of both myocardial thickening and wall motion will be necessary for the proper evaluation of regional myocardial contraction in ischemic heart disease.

Adult↗
PubMed1983

Light-induced delta pH of envelope vesicles containing halorhodopsin measured by use of a spin probe.

The spin-labeled amine, 4-amino-2,2,6,6-tetramethyl-piperidino-N-oxyl was used to measure the photoinduced delta pH in the envelope vesicles derived from mutant cells of Halobacterium halobium. The cells contain halorhodopsin (hR) and are spectroscopically free from bacteriorhodopsin (bR). The EPR signals from the extravesicular populations of the probe was quenched by ferricyanide. The membrane bound population of the probe was less than 1% of the amount of the probe entrapped within the vesicle. Hence, we can monitor continuously the concentration of the intravesicular populations of the probe and delta pH can be calculated from the line height of the signal. The kinetic analysis indicated that the time course of the change in the EPR signal represents faithfully delta pH of the vesicle. At pH 7.5, the photoinduced delta pH showed a maximum. The kinetic constant of pH change also displayed a peak at this pH. Addition of uncoupler did not increase either the rate nor magnitude of delta pH at this pH, but at other pH, especially at lower pH, uncoupler showed its effect. A theoretical equation was derived which correlated the photocycle of hR with delta pH. According to the analysis by use of this equation, the time constant of the photocycle was suggested to be constant in pH ranging from 5.5 to 8.25. The maximum in photoinduced delta pH observed at pH 7.5 was concluded to be due to the permeability dependence of ions, especially of H+ on pH. The temperature dependence of delta pH was measured. As the temperature decreased, delta pH was, surprisingly, found to be increased. The rate constant of the photocycle analyzed by the equation, however, decreased with decrease of temperature.

Bacterial Proteins↗
PubMed1983

A case of ureteral intussusception associated with ureteral polyp.

We report a case of left ureteral intussusception associated with a ureteral polyp. At operation a 7 cm. long polyp was seen originating from the tip of the inside of the proximal ureter, causing 1.7 cm. of antegrade invagination. The polyp was resected and the invaginated region was repaired since pathological examination revealed a benign tumor. At followup an excretory urogram demonstrated prompt improvement of left hydronephrosis.

Female↗
PubMed1983

Effect of 24-hour ureteral obstruction on subsequent ischemic damage in rat kidney.

The effects of prior 24-hour ureteral obstruction on ischemic renal damage were studied in rats. Rats were divided into 6 groups with different times of ischemia (0, 60 and 90 min) and with or without 24-hour ureteral obstruction. Following a 4-week recovery period, contralateral nephrectomy was performed and the rat was sacrificed 24 h later for the determination of serum creatinine and for histologic examination of the affected kidney. A preceding ureteral obstruction for 24 h made no difference to the renal damage with 60 min of ischemia or without ischemia. However, kidneys with 90 min of ischemia and 24 h of ureteral obstruction were more damaged than those with 90 min of ischemia only. These results suggested that the hydronephrotic kidney was more susceptible to long periods of ischemia than the normal kidney.

Animals↗
PubMed1983

Individual renal function study using computed tomography.

Using computed tomography, the renal parenchymal volume and tissue-plasma ratio of contrast enhancement, with a bolus injection, were measured, and the latter measurement is believed to indicate regional renal function per unit of parenchymal volume. 67 studies were carried out on 50 patients, 17 of whom were examined pre- and postoperatively. Of these 50 patients, 27 had hydronephrosis, 6 had renovascular disease, 4 had pyelonephritis and the remaining 13 were control patients. The product of tissue-plasma ratio of contrast enhancement and the calculated renal parenchymal volume were found to be in good correlation with the individual renal function measured with 99mTc-dimercaptosuccinic acid and 131I-hippuran. Since this method is reproducible, the kidney being examined may be seen in more detail.

Creatinine↗
PubMed1983

R wave changes in patients with myocardial infarction during treadmill stress testing.

A graded multistage treadmill exercise test was performed on 78 patients with myocardial infarction (65 males and 13 females, ranging in age from 30 to 76). The amplitude of the R wave in CC5 was measured at rest and during the periods of peak exercise. The exercise-induced R wave changes were classified into 3 groups: increased, 39.1%; no changes, 39.7% and decreased, 22.2%. Acute attacks of myocardial infarction were more severe in the patients whose R wave decreased during exercise than in those whose R wave increased. Heart rate, blood pressure and pressure rate products were not different among the groups. However, oxygen consumption was greater in the R-increased group than in the R-decreased group. Therefore, an increase in R wave amplitude during exercise in post-myocardial infarction patients indicates a good efficiency of the myocardium and skeletal muscles. Exercise-induced changes of the mean electrical axes of the transverse plane were significantly related to changes of the R wave amplitude in CC5 (r = 0.50, p less than 0.001). Therefore, change in the transverse plane axis is one of the important determinants of exercise-induced R wave changes.

Adult↗
PubMed1983

Exercise capacity of the patients with myocardial infarction.

This study was conducted to investigate the functional capacity in postmyocardial infarction. Eighty-four multistage treadmill exercise tests were performed on 60 patients, none of whom had had any formal rehabilitation or regular exercise. There were 50 men and 10 women, ranging in age from 30 to 81 with an average age of 60. The time interval between the acute attack and the exercise test ranged from one month to 9 years. Even though severe infarction affects the exercise capacity for a long time after an acute attack, its effect on cardiac function was more obvious than that on physical capacity. Age was the most important determinant of physical capacity, and the slope of decreasing physical capacity with age in patients with infarct was the same as that in normal subjects. Cardiac function also decreased with age. However, during the early recovery phase, cardiac function was influenced by the severity of infarction and the influence of age could not be established. There was no significant correlation between early ambulation and physical capacity. The beneficial effects of early ambulation may be lost if physical activity is discontinued for some time after the acute attack. The physical capacity increased 2-3 years after the acute attack, but myocardial function did not change significantly.

Adult↗
PubMed1983

In-hospital rehabilitation at the recovery phase after acute myocardial infarction.

In order to investigate how rehabilitation during hospitalization influences the prognosis of patients with acute myocardial infarction, the authors investigated 496 cases, including 405 males and 91 females hospitalized in the institutes participating in the Cardiac Rehabilitation Research Conference, during the period of 10 years from 1969 through 1978. Patients' ages averaged 59.2 years for males and 66.5 years for females. The total number of deaths during the average follow-up period of 5 years and 7 months was 104 (21.0%), of which 73 cases of cardiac death were included, showing 14.7% of the total cases and 70.2% of the total deaths. The incidence of bed-ridden patients after discharge was as low as 1.0%, and the rate of returning to work varied according to age: it decreased from 86.7% to 9.3% with age, averaging 54.4%. The rate of rehabilitation performance in the hospitals was 73.7% for patients under 69 years of age and 48% for those under 70. The rate of cardiac death was 8.4% in the rehabilitated group (exercise group), and 27% in the non-rehabilitated (control) group, and the rates of returning to work were 50.2% and 25%, respectively, and there were significant differences in both the mortality rate and the working rate between these 2 groups (p less than 0.01). As for the severity of myocardial infarction, the more severe the disease, the wider the difference in the prognosis between the exercise and the control group.

Aged↗
PubMed1983

[Acute toxicity of intrarectally administered (ketoprofen (T10) in rat weanlings].

Acute toxicity of Ketoprofen, a nonsteroidal antiinflammatory analgestic, was studied using rat weanlings. Ketoprofen was intrarectally administered in the form of a mixture with T10, a basic materials for suppositaries. The results obtained were as follows: LD50 of KP was estimated to be 434 mg/kg in male weanlings and 496 mg/kg in female weanlings. These values were about four times higher than those obtained from our previous study (Shimpo et al., 1981) using six-weeks old adult rats of both sexes. The fact indicated that rat weanlings were far tolerant to KP intrarectally administered than young adult rats. Intrarectal administration of KP at high doses, caused death between the second and the seventh day after administration. Gross and histopathological examinations revealed that dead weanlings carried perforative peritonitis with ulcers mainly in jejunum and ileum not in rectum. It was therefore suggested that the ulcer was produced in small intestine by entero-hepatic circulation of KP and finally mortal peritonitis occurred.

Age Factors↗
PubMed1983

[Carcinogenicity study of cholestyramine in rats].

Carcinogenicity study on cholestyramine, an anti-hypercholesterolemic agent, was carried out using Fischer rats by feeding with a normal pellet diet (control) and with three sorts of the pellet diets in which cholestyramine was admixed in the common diet at the rates of 1.25, 2.5 and 5%, respectively. The animals were fed with these diets for 26 months and a normal diet for subsequent 2 months. Some of the male rats fed with the 5% admixed diet revealed a slight growth retardation and occasionally hemorrhagic tendency, without resulting in severe macroscopic and microscopic lesions of the internal organs and in shortening of the mean survival time as compared with that of the control group. The rates of tumor-bearing animals were high in all experimental groups including the control, but the rates were not considered to be drug-related. Incidences of individual tumors were not significantly different each other between cholestyramine-fed groups and control group. Thus, it was not recognized that cholestyramine induced any drug-related specific tumors and an accelerated growth of any tumors.

Animals↗
PubMed1983

[Teratogenicity study on ranitidine hydrochloride in rats].

A teratogenicity study was carried out in Crj: CD (SD) rats orally administered ranitidine hydrochloride, a histamine H2-receptor antagonist, at dose levels of 50, 200 and 800 mg/kg/day as base weight for a period of 11 days from day 7 to day 17 of gestation. Two-thirds of the pregnant females in each group were sacrificed on day 20 of gestation and their fetuses were examined. The remaining dams were allowed to litter naturally, and the postnatal development of the offspring was observed. The incidences of external, internal, and skeletal anomalies were not significantly increased in the fetuses of any treated group. Ranitidine treatment caused no effects on parturition, lactation, postnatal growth and reproductive ability of the male and female offspring.

Administration, Oral↗
PubMed1983

[Effects on offsprings induced by oral administration of ranitidine to the female rat in peri- and postnatal periods].

A perinatal and postnatal study was carried out in the Crj:CD (SD) rats orally administered ranitidine hydrochloride, a histamine H2-receptor antagonist, at dose levels of 50, 200, and 800 mg/kg/day as base for a period of time from day 17 of gestation to day 21 after delivery. All pregnant rats were allowed to litter naturally, and the postnatal development of the offsprings was observed. In the 800 mg/kg group, the delivery rate was significantly decreased and offspring mortality during the lactation period showed a tendency to increase as compared with control, but the difference was not significant. No significant differences between the control group and the treated groups were found in postnatal growth and differentiation, behavior and reproductive ability of male and female offsprings.

Administration, Oral↗
PubMed1983

[Chronic toxicity study of ranitidine hydrochloride orally administered in rats].

Chronic toxicity of ranitidine hydrochloride, a new histamine H2-receptor antagonist, was studied using Sprague Dawley rats. Ranitidine was administered orally at dose levels of 30, 100, 300 and 1000 mg/kg/day for 26 or 53 weeks. In the 1000 mg/kg/day group, ten of 31 females died showing acute toxic signs. In the survived animals of this dose group, changes were observed, such as salivation, depression of body weight gain, increase in water consumption, increase in urinary Na and K excretion, increase in serum albumin content, increase in weights of the liver, kidneys and heart. Main histopathological findings were as follows: centrolobular or midzonal fat deposition in liver, increase in s-ER in hepatocytes, increase in foamy cells in lung and some slight degenerative changes occasionally seen in renal tubules. In the 300 mg/kg/day group, the changes similar to those in the 1000 mg/kg/day group were observed, however, the degree of these changes was more moderate. All of the above-mentioned findings were demonstrated to be reversible in recovery period for 8 weeks. In the 100 and 30 mg/kg/day groups, no remarkable changes were observed in both sexes. It was concluded that the maximum nontoxic dose of ranitidine hydrochloride was 100 mg/kg/day in male and female rats.

Administration, Oral↗