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Biomedical subjects

K Kuramoto

Publications and source records attributed to K Kuramoto.

At least 145 records · Page 8Linked to original sources
PubMed1986

Antihypertensive treatment with metoprolol or hydrochlorothiazide in patients aged 60 to 75 years. Report from a double-blind international multicenter study.

In a randomized double-blind study (N = 562), a traditional treatment schedule, starting antihypertensive treatment in elderly hypertensive patients (60 to 75 years old) with 25 mg of hydrochlorothiazide once daily and doubling the dose if a satisfactory response was not achieved, was compared with antihypertensive treatment of 100 mg of metoprolol once daily, adding 12.5 mg of hydrochlorothiazide for patients whose response was not satisfactorialy achieved with metoprolol alone. Systolic and diastolic blood pressure was significantly reduced with both regimens. The frequency rates of responders (diastolic blood pressure, less than or equal to 95 mm Hg) in the metoprolol group and the hydrochlorothiazide group were 50% and 47% after four weeks and 65% and 61% after eight weeks, respectively. There were no significant differences in total symptom score or single symptoms between the regimens, but significantly more patients had hypokalemia and hyperuricemia with the hydrochlorothiazide regimen. Thus, we conclude that beginning antihypertensive treatment with 100 mg of metoprolol once daily and adding a small dose of hydrochlorothiazide (12.5 mg) in patients whose response is not satisfactory with metoprolol alone appears to be effective and safe in elderly hypertensive patients.

Aged↗
PubMed1986

Clinical evaluation of bisoprolol in patients with hypertension: interim report.

The antihypertensive effect and possible adverse effects of bisoprolol were assessed in 96 Japanese patients with mild to moderate hypertension. After a 2- to 4-week placebo period, bisoprolol was administered to 68 outpatients at a daily dose of 5 mg to 20 mg for 6 to 8 weeks, and to 28 inpatients with the same dose range up to a maximum of 4 weeks. For outpatients, blood pressure and heart rate were recorded every 2 weeks, while for inpatients, in addition to daily measurements, the effect of bisoprolol on diurnal variation of blood pressure was also studied. Bisoprolol lowered blood pressure and heart rate significantly in both groups of patients. The most common adverse effect was bradycardia. It is expected that bisoprolol will be a very effective and useful antihypertensive drug.

Adrenergic beta-Antagonists↗
PubMed1985

Biopharmaceutical evaluation of methylcellulose as an excipient for nitroglycerin tablets.

To examine the bioavailability of nitroglycerin in sublingual tablet, 5 healthy adult volunteers underwent simultaneous sublingual administration of a tablet prepared with methylcellulose and a tablet prepared with lactose containing 0.15 mg of nitroglycerin and 0.15 mg of nitroglycerin-15N3, respectively. In 4 of 5 volunteers, no difference in plasma concentration determined by gas chromatography-mass spectrometry (GC-MS) was observed between 2 tablets described above, so it was well accepted that nitroglycerin in tablets prepared with methylcellulose had a similar bioavailability to that in tablets prepared with lactose. The simultaneous administration of the 2 nitroglycerin tablets to a healthy volunteer, one of which containing the drug labeled with a stable isotope followed by GC-MS assay, seems to be the most suitable method for a precise comparison of bioavailability of the formulations.

Adult↗
PubMed1985

The treatment of mild hypertension in the elderly, a prospective study using multiple regression analysis.

In order to examine the effect of treatment of mild hypertension of the aged, a 4 year prospective trial was performed in 41 placebo and 38 drug-treated patients with an average age of 76.5 years. Patients were matched for blood pressure, sex and age. Patients with cardiovascular complications or blood pressure elevation above 200/110 were categorized as dropouts and totaled 17 cases (41.5%) in the placebo group, and 4 cases (10.5%) in the drug-treated group (p less than 0.01). In diastolic hypertension, dropouts formed 63.6% of the placebo group (mean BP, 170/92), and 9.5% of the drug group (mean BP, 179/94) (p less than 0.001). In systolic hypertension, dropouts were of 15.8% in the placebo group (mean BP, 164/79), and of 11.8% in the drug group (mean BP, 167/79), and no significant difference was observed. In the placebo group, dropouts were significantly higher in patients with pretreatment systolic blood pressure over 170 mmHg or diastolic blood pressure over 90 mmHg. In patients of 75 years of age or more, dropouts were 46.4% in the placebo group, and 13.0% in the drug treated group showing the beneficial effect of drug treatment even in those over the age of 75. However, no beneficial effect was observed over the age of 85. Stepwise multiple regression analysis of total case revealed that the greatest predictor for dropout was the presence of placebo (i.e. no treatment), explaining 12.2% of the variation in future dropout. Similarly, diastolic hypertension explained 7.5%, creatinine 6.7%, and age 4.6% of this variation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1985

[Mitral valvular disease secondary to mitral ring calcification: a clinicopathologic study].

Fifteen cases with mitral valvular disease caused by mitral ring calcification (MRC) were observed among 2,800 consecutive autopsy patients more than 60 years of age. They consisted of one man and 14 women whose average age was 86.4 years. All had been diagnosed as having mitral valvular disease during life. For this clinicopathologic study, the cases were categorized as nine cases with mitral regurgitation (MR Group) and six with mitral stenosis (MS Group). Among the 15 cases, phonocardiograms were obtained in 14 and echocardiograms in 6. In addition, 122 cases with MRC, the length of which was 5 mm or more, were selected from 900 recent consecutive autopsies of senile patients, to evaluate the site of calcification and to analyze the ratio of calcification length to mitral valve ring circumference. The following conclusions were obtained: The prevalence of mitral valvular disease due to MRC in the aged was 15/2,800 (0.5%). MR was observed in nine cases and MS in six. Phonocardiograms of the MR Group revealed a holosystolic murmur in seven cases, a late systolic murmur in one, a third heart sound in four and a fourth heart sound in five. In the MS Group, a holosystolic murmur was found in four, a presystolic murmur in four, a diastolic rumble in one, but no opening snap in any case. A diamond-shaped systolic murmur was found in nine cases with MS or MR, suggesting an ejection systolic murmur caused by an associated calcified aortic valve. Echocardiograms showed markedly decreased DDR in five cases and increased echo intensity of the aortic valve in four. Pathologic findings revealed that the mean length of MRC was 36.6 mm in the MR Group and 58.0 mm in the MS Group. The calcification ring ratio (CRR = MRC/MVR X 100) was 50.3% in the MR Group and 69.8% in the MS Group. In the MR Group, MRC involved the anterolateral commissure in three, posteromedial commissure in five, and both in one. In five of six cases with MS, both commissures were involved by MRC. The study of 122 cases with MRC length greater than or equal to 5 mm suggested that MRC occurred first in the middle scallop of the posterior mitral leaflet, and extended to the posterior scallop, subsequently extending up to the anterior scallop, and finally involved the anterior mitral leaflet beyond the commissures.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1984

Peripheral arterial disease diagnosed with high-count-rate radionuclide arteriography.

Thirty-seven patients with peripheral vascular disease involving the legs were studied with first-pass peripheral radionuclide arteriography (RNA) and contrast arteriography to determine whether RNA could be used to evaluate perfusion of the toes. Data were acquired for 100 seconds using a multicrystal gamma camera following bolus injection of 30-35 mCi (1,110-1,295 MBq) of Tc-99m-labeled albumin during reactive hyperemia. Peripheral time-activity curves were examined and the time required for activity to decline to 75% of peak activity ( T75 ) was recorded. When an abnormal RNA was defined as T75 greater than or equal to 50 seconds, sensitivity was 92%, positive predictive accuracy 100%, and negative predictive accuracy 75%. These data suggest that peripheral RNA of the toes is a reliable, noninvasive procedure for evaluation of peripheral arterial disease; it can be valuable as a screening test prior to contrast arteriography as well as for follow-up.

Adult↗
PubMed1984

Differential rate of age-related decline in immune functions in genetically defined mice with different tumor incidence and life span.

Immunological studies were performed in aging C57BL/6 and BDF1 mice. In C57BL/6 mice the incidence of malignant tumor was high and their mean life span was 665 days in males and 649 days in females. In BDF1 mice, the incidence of malignant tumors was significantly lower, and their mean life span was 954 days in males and 846 days in females. Immunologically, either the onset of decline occurred earlier, the rate of the age-related decline in activity was more rapid, and/or the magnitude of decline was greater in the shorter-lived C57BL/6 than in the longer-lived BDF1 mice. The close relationship between (a) the susceptibility especially to malignant lymphoma; (b) the onset, rate and magnitude of age-related decline in T-cell-dependent immunologic activities, and (c) the life span would suggest that T-cell immunity may be playing an important role in the resistance against life-shortening malignant lymphoma in C57BL/6 mice.

Aging↗
PubMed1984

Nonbacterial thrombotic endocarditis as a cause of cerebral and myocardial infarction.

Clinicopathologic correlations of nonbacterial thrombotic endocarditis (NBTE) were studied with special reference to their pathogenetic role in cerebral and myocardial infarction. In 2340 cases of consecutive autopsies of the aged, NBTE was observed in 217 cases or 9.3%. The age distribution of NBTE revealed a gradual increase with advancing age. The underlying diseases of NBTE were malignant neoplasm (51.6%), infection (28.3%) and other diseases (20.1%). The incidence of NBTE in each cancer was high in cancers of the colon (16.2%), pancreas (15.2%), gall bladder or bile duct (14.1%) and lung (13.0%). The vegetations of NBTE were found on the aortic valve in 46.1%, on the mitral valve in 40.6% and on the both valves in 8.3%. The incidence of myocardial infarction and scar was 51.2% in the NBTE group, while it was 38.6% in the non-NBTE control group (p less than 0.02). This difference was marked in patients with a small infarction (10.6% vs. 5.3%) and a myocardial scar (30.4% vs. 19.0%). The grade of coronary stenosis was less in the NBTE group than in the control group (p less than 0.001), suggesting that the origin of the myocardial ischemic lesion was embolism from NBTE. The incidence of large cerebral infarction was 14.7% in NBTE and 9.2% in the control group, and that of medium sized cerebral infarction was 35.0% and 23.6% respectively. In this latter group, cortical infarction comprised 57.9% in the NBTE group and 26.6% in the control group. In large cerebral infarction, cerebral atherosclerosis was less severe in NBTE than in the control group (p less than 0.001), also suggesting an embolic mechanism. Disseminated intravascular coagulation was found in 41.9% of NBTE.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1984

Atrial fibrillation as a cause of myocardial and cerebral infarctions.

Pathogenetic role of atrial fibrillation (AF) on myocardial and cerebral infarctions was studied in 2340 consecutive autopsies of the aged. AF was found in 405 cases or 17.3%, and the incidence of AF increased with age. Myocardial infarction and scar were found in 56.8% in AF, but in 36.4% in non-AF (p less than 0.001). Small myocardial infarction was 2.9 times (12.6% vs. 4.3%), and the scar was 1.5 times (27.2% vs. 18.7%) as prevalent in AF as in non-AF. Intracardiac mural thrombus was found in 14.8% in AF and in 4.8% in non-AF, 8 to 10 times as prevalent in small myocardial infarction (29.4% vs. 3.7%) and scar (17.4% vs. 1.7%) in AF as in non-AF. Coronary stenotic index revealed no difference between AF and non-AF. Large cerebral infarction was observed in 21.9% in AF and 7.3% in non-AF, and this difference was prominent in cases with myocardial infarction or myocardial scar indicating the common pathogenetic role of AF. In cases with large cerebral infarction severe cerebral atherosclerosis was less frequent in AF than in non-AF. Medium sized cortical infarction was also prevalent in AF. The prevalences of myocardial and cerebral infarctions were not different in AF complicated with valvular heart disease from those without it, but increased in the permanent AF in comparison to the transient AF. AF induced small myocardial infarction and large or medium sized cerebral infarctions by embolism from mural thrombus. The mechanism for the difference in size is discussed.

Aged↗