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Biomedical subjects

K Kuramoto

Publications and source records attributed to K Kuramoto.

At least 55 records · Page 3Linked to original sources
PubMed1995

Production of term offspring by in vitro fertilization using old mouse spermatozoa.

We successfully produced offspring of old male BDF1 mice using in vitro fertilization. Although 7 old male mice (33 months of age) were infertile and revealed frequent degeneration in the seminiferous epithelia, 4 of them had spermatozoa in the caudae epididymides. The IVF rate of their sperm with eggs from young ICR mice was very high (82.0%). The production rate of offspring was also satisfactory (61.6%). The present study indicates that the IVF method is useful for producing offspring of aged male mice.

Aging↗
PubMed1995

[Perceived quality of life and social factors in elderly hypertensive patients].

We conducted a cross-sectional study of elderly outpatients with hypertension to examine the relationship between quality of life (QOL) scores and social background factors. The subjects consisted of 516 outpatients (267 females), age of 60 or over, at nine clinics of major hospitals which participated in the National Cardiovascular Center Research Project. The perceived QOL was evaluated by the QOL scale originally based on Japanese patients with cardiovascular diseases. The scale consisted of the following 5 subscales; difficulty due to disease, psychological stability, independence, satisfaction in daily living and vitality. The background factors included family structure, socioeconomic factors and work status, and physical activity of daily living (ADL). After adjusting for age, sex, administered drugs and complicating conditions such as ischemic heart disease and/or apoplexy, a significant odds ratio of a low score of difficulty due to disease, psychological stability, satisfaction in daily living and vitality was found in the impaired physical ADL group with low socioeconomic class, and a significant odds ratio of low score of independence were found in the impaired physical ADL group who had lost jobs due to illness and had no children.

Aged↗
PubMed1995

[Spatial and temporal alteration of the dual supply of the hepatic circulation with transient occlusion of the hepatic veins: spiral volumetric CT during arterial portography and arteriography].

To elucidate the contribution of hepatic veins to the blood flow of liver, CT arterial portography and/or arteriography was performed in eight patients having hepatocellular carcinoma with transient occlusion of the hepatic vein and eight without occlusion. In each patient with occlusion of the hepatic vein, CT showed a well-demarcated fan-shaped area of low density during arterial portography and increased density during arteriography in the corresponding area. Hepatic vein occlusion could result in the pooling of arterial blood in the liver parenchyma. Transient segmental hepatic venous occlusion might improve the results of transcatheter arterial infusion and transcatheter arterial embolization for liver tumors.

Adult↗
PubMed1994

Age-related changes in cytoskeletal components of the BDF1 mouse Sertoli cell.

Age-related changes in mouse Sertoli cell cytoskeletal components (F-actin, vimentin and cytokeratin) were investigated by light and transmission electron microscopy and immunofluorescence using BDF1 mice from 3-33 months of age. In old mice (30 and 33 months of age), the testicular seminiferous epithelia were extremely thin, containing scarce round spermatids and spermatocytes with no elongated spermatids. In these epithelia, the Sertoli cells had lost their polarity and had become flattened. F-actin was detectable at the junction between adjoining Sertoli cells and around the spermatid head in young mice. In old mice, F-actin was distributed at the junction between adjacent Sertoli cells, around the spermatid head, and at the luminal side of the Sertoli cell cytoplasm. Vimentin was detected around the Sertoli cell nucleus and extended into the Sertoli cell trunk towards the tubular lumen in young mice. In old mice testes, however, vimentin was recognized around the Sertoli cell nucleus, but not in the Sertoli cell trunk. Additionally, sheet-like reactions of vimentin, running parallel to the basement membrane, were detected near the luminal surface. Although cytokeratin was not detected in the Sertoli cells of mice until 27 months of age, it was obvious in the extremely thin seminiferous epithelia of older mice. Cytokeratin was randomly distributed within the Sertoli cell cytoplasm. In these Sertoli cells, the expression of vimentin was concurrently detected. Detection of cytokeratin in the extremely thin seminiferous epithelia is one of the most characteristic phenomena of age-related testicular changes in Sertoli cells of older mice.

Actins↗
PubMed1994

The efficacy of monatepil, a new calcium antagonist, in the treatment of essential hypertension.

A multicenter, open-label trial in Japan examined the efficacy, safety, and optimal dose of monatepil (AJ-2615) as monotherapy and in combination therapy with angiotensin-converting enzyme (ACE) inhibitors or beta-blockers. Patients with essential hypertension who had never been treated or had been refractory to conventional antihypertensive agents were enrolled in the trial. During a 4-week control period patients assigned to monotherapy received placebo and those assigned to combination therapy received an ACE inhibitor or beta-blocker and placebo. Patients with systolic blood pressure (BP) > or = 160 mm Hg and diastolic BP > or = 95 mm Hg at the end of the control period were enrolled in the study. The initial dose of monatepil was 30 mg/day in monotherapy and 15 mg/day in combination therapy; the daily dose was titrated to 60 mg/day according to the antihypertensive response. The treatment period was 8 to 12 weeks. Blood pressure decreased from 168 +/- 8/100 +/- 6 to 142 +/- 9/85 +/- 7 mm Hg (SD) with monatepil monotherapy, from 171 +/- 11/102 +/- 6 to 141 +/- 9/84 +/- 6 mm Hg in combination with ACE inhibitors, and from 175 +/- 13/102 +/- 7 to 153 +/- 21/91 +/- 9 mm Hg in combination with beta-blockers (P < .001). When patients in whom mean BP decreased by > or = 13 mm Hg were defined as responders, the response rate was 80.4%, 78.1%, and 51.6% in the respective groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1994

[Examinations to detect left atrial thrombus and blood coagulation test analyses in aged patients with atrial fibrillation].

To screen for risk of embolism, we investigated the association between the presence of left atrial (LA) thrombus by transesophageal echocardiography (TEE) and blood coagulation tests, including thrombin-antithrombin III complex (TAT), plasminogen activator inhibitor 1 (PAI-1), plasmin-alpha 2-plasmin inhibitor complex (PIC), D-dimer, tissue plasminogen activator (tPA), free tPA, tPA.PAI-1 complex, prothrombin fragment 1+2 and fibrin degradation product E (FDP-E) in 40 patients with atrial fibrillation (Af) (13 males, 27 females, mean age 76 +/- 8 yrs). Blood coagulation tests were performed in 21 control subjects with sinus rhythm (12 males, 9 females, mean age 75 +/- 4 yrs). LA thrombi were detected in the appendage of 8 patients and in the atrium of 6 patients. Severe atherosclerotic plaque with thrombi in the thoracic aorta were detected in 6 patients without LA thrombi. FDP-E, D-dimer and PIC increased significantly in patients with LA thrombi or aortic plaque in comparison with controls with sinus rhythm. In patients with Af, 25 of them (group A) has more than 4 abnormal coagulation values out of 9 tests and 15 of them (group B) had abnormalities in less than 3 tests. LA thrombi or aortic plaque were detected in 18 patients in group A and 2 patients in group B (72% vs 13%, p < 0.01). In 4 of 6 patients with large LA thrombi, the thrombi were resolved after administration of warfarin. Before administration of warfarin, tPA, PA-1 and tPA.PA-1 complex levels were higher in the two patients whose thrombi did not resolve.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

[Effect of warm bathing on short-term and 24-hour blood pressure in bedridden elderly patients].

The effects of the bathing on short-term and ciracadian blood pressure (BP) in bedridden elderly patients were investigated in 10 bedridden patients (4 male: 6 female) living in a community home. The mean age of the subjects was 78.7 years old and causes of bedridden status were cerebrovascular disease in 9 and spinal damage in one. To study the short-term hemodynamic effect of bathing, BP and pulse rate were measured every 2 minutes from 10 minutes before bathing to 14 minutes after. Blood samples were collected before and after bathing for measurements of plasma catecholamine and plasma renin activity. To study the effect of warm bathing on circadian, BP, ambulatory BP was non-invasively monitored every 15 minutes for 24 hours on days with and without bathing. In the short-term phase, BP temporally elevated when washing the body outside the bathtub accompanied with a decline soaking in warm water (38 degrees C). Plasma catecholamine did not change after warm bathing. In the study of circadian change of BP, systolic BP on days of warm bathing remained at a lower level for 12 hours after bathing compared to days without bathing. In conclusion, hypotensive effects after bathing were prolonged in the bedridden elderly patients.

Aged↗
PubMed1994

Treatment of elderly hypertensives in Japan: National Intervention Cooperative Study in Elderly Hypertensives. The National Intervention Cooperative Study Group.

PREVALENCE OF HYPERTENSION IN ELDERLY JAPANESE PATIENTS: Data collected from post-mortem information at the Tokyo Metropolitan Geriatric Hospital showed that the overall prevalence of hypertension in Japanese patients aged over 60 years was 53%; one-third of these elderly hypertensives had isolated systolic hypertension. Isolated systolic and systolodiastolic hypertension were each associated with a similar degree of increased atherosclerosis and cardiovascular complications. In a placebo-controlled study antihypertensive treatment produced a reduction in withdrawal from treatment in elderly patients with mild hypertension. INTERIM TRIAL RESULTS: Some interim results have been obtained from a new trial which is currently under way in Japan, the National Intervention Cooperative Study for the Treatment of Elderly Hypertensives, a long-term study comparing the effects of a calcium antagonist (nicardipine) and a thiazide diuretic (trichlormethiazide) on cardiovascular complications in elderly patients with mild to moderate hypertension.

Aged↗
PubMed1993

[The evaluation of lung cancers hidden by the mediastinal and hilar shadows on the plain chest film].

We retrospectively evaluated the plain chest frontal radiographs in four cases in which the lung cancers were quite difficult to observe prospectively on plain chest frontal radiographs in spite of the relatively large size of tumors (over 3 cm in diameter). Three of four cases were central-type lung cancers, two squamous cell carcinomas and one adenosquamous cell carcinoma. Since there was no associated atelectasis or obstructive pneumonia in these cases, wall thickening and indistinctness of the lumen of the central bronchi were the significant findings for diagnosis. One case proven to be adenocarcinoma was located in the periphery of S6. A focally increased radiopacity behind the descending pulmonary artery was the only finding to pointed out. Since tumors were not demonstrated directly in the aerated lungs, the condition of the central bronchi as well as the degree radiopacity of the pulmonary artery should be carefully interpreted.

Adenocarcinoma↗
PubMed1993

Food restriction suppresses an age-dependent increase in the exhalation rate of pentane from rats: a longitudinal study.

Longitudinal age changes in the exhalation rates of ethane and pentane, which are used as the indices of in vivo lipid peroxidation, from rats under ad libitum feeding and food restriction were measured. The exhalation rate of ethane or pentane from old, ad libitum-fed rats is higher than that of the corresponding hydrocarbon from young, ad libitum-fed rats, as reported previously. There is no difference between the exhalation rates of each hydrocarbon from young, ad libitum-fed and food-restricted rats. However, the exhalation rate of pentane from old, food-restricted rats is significantly lower than that from old, ad libitum-fed rats, while the exhalation rate of pentane from old, food-restricted rats tends to be lower than that from old, ad libitum-fed rats. In addition, the exhalation rate of pentane from old, food-restricted rats is equivalent to that from young, ad libitum-fed rats. These results are consistent with the views that in vivo lipid peroxidation in rats is increased during aging, and that the age-dependent increase in in vivo lipid peroxidation is suppressed by food restriction.

Aging↗
PubMed1993

Effects of alpha,beta-blocker, arotinolol chloride, on 24-h blood pressure--difference between elderly and younger hypertensive patients.

To assess the effect of age on the circadian blood pressure (BP) after an alpha,beta-adrenergic blocker, the ambulatory BP was measured before and after arotinolol chloride administration in nine younger (mean age 49.1 years) and 14 older (72.1 years) patients with essential hypertension. After a 4-week control period, arotinolol chloride was administered twice daily (08:00 and 20:00 hours) for 8 weeks and the ambulatory BP was measured non-invasively at the end of the control and treatment period. Arotinolol significantly reduced the daytime systolic BP from 152.3 to 140.9 mmHg (P < 0.05) and night-time systolic BP from 137.3 to 122.3 mmHg (P < 0.01) in the younger hypertensive patients. In contrast, in the older group, the night-time systolic BP did not show a significant change, although the daytime systolic BP was significantly reduced from 155.0 to 142.2 mmHg (P < 0.02). Diastolic BP in both groups was significantly reduced by arotinolol during the day and night. Night-time reduction of BP was significantly less in the older group (-8.6 vs -15.1 mmHg for the systolic pressure P < 0.01; -5.8 vs -9.8 mmHg for the diastolic pressure P < 0.01).

Adrenergic beta-Antagonists↗
PubMed1993

Is white coat hypertension innocent? Structure and function of the heart in the elderly.

To evaluate the morphological and functional characteristics of the heart in elderly patients with white coat hypertension, we performed an echocardiographic study in 67 elderly individuals older than 60 years: 17 patients with white coat hypertension, 34 patients with true hypertension, and 16 normotensive control subjects. White coat hypertension was defined as a mean 24-hour ambulatory systolic blood pressure of less than 140 mm Hg associated with office hypertension. Cardiac responses to an isometric handgrip exercise test were used to evaluate left ventricular functional reserve. Left atrial dimension and left ventricular mass index were significantly greater in the white coat hypertension group than in the normotension group (P < .05) but were similar to values in the true hypertension group. Left ventricular diastolic function, expressed by peak late-early filling ratio of diastolic mitral flow, showed increasing impairment in the order of the normotension, white coat hypertension, and true hypertension groups (analysis of variance, P < .05); the ratio in the white coat hypertension group tended to be higher than that in the normotension group (unpaired t test, P = .054). The relation between fractional shortening and end-systolic stress did not shift downward after handgrip exercise in the white coat hypertension group, indicating that functional reserve in the left ventricle was maintained. Thus, patients with white coat hypertension had a moderately increased left atrial dimension and left ventricular mass in association with a tendency for disturbed diastolic function, although systolic functional reserve remained the same. These findings suggest that white coat hypertension in the elderly may not be innocent.

Aged↗
PubMed1993

Age-related morphological changes in the testis of the BDF1 mouse.

Age-related morphological changes in the testis of the BDF1 mouse were studied by light and transmission electron microscopy. No apparent changes were detected until 12 months of age. After 18 months of age, vacuoles firstly appeared in the seminiferous epithelium. These vacuoles were gradually increased in number and showed a tendency to cluster with each other in accordance with age. While, germ cells were decreased in number. The sloughing of germ cells caused a thin seminiferous epithelium. In the tubule with a thin epithelium, spermatogenesis was severely interrupted. After 30 months of age, extremely thin seminiferous epithelia were observed. In these epithelia, most of spermatids and spermatocytes disappeared, and most of Sertoli cells lost their polarity to be flattened. On the other hand, in the interstitial region, PAS-positive cells (mononuclear phagocytes) tended to increase in number after 24 months of age. PAS-positive extracellular matrix newly appeared at 27 months of age. In the cytoplasm of Leydig cells, a whorl of sER was frequently found. Degeneration of testes proceeded with age. The regressive tubules occupied only 2.2% at 18 months of age, but extended to 63.0% at 33 months.

Aging↗
PubMed1993

The relationship between ambulatory blood pressure and physical activity in young and older shiftworkers. A quantitative assessment of physical activity using a microcomputer with acceleration sensor.

We studied the relationship between physical activity and ambulatory blood pressure (BP) in young and older shiftworkers by simultaneous recordings of activity, blood pressure and pulse rate (PR). Activity was assessed using Activetracer, a self-contained microcomputer with an acceleration sensor, attached to a waist belt. Ambulatory BP was monitored every 30 minutes for 48 hours with a TM2421. Three types of hemodynamic responses were noted in relation to the physical activity. The balance type, in which both BP and PR increase with physical activity, was observed in 5 of 10 young cases (50%) but only in 1 of 7 older cases (14.3%). The BP response type, in which the BP increases with no change in the PR, was observed in 6 of the 7 older (86%) but only in 3 cases in the young group (30%). The PR response type, in which only the PR increase correlated with activity, was observed in 2 cases in the young group (20%) and none in the older group. The difference in systolic BP between periods of activity and rest in the older shiftworker was significantly larger than that in the young group (15.9 +/- 6.4 vs. 5.9 +/- 6.6 mmHg, p < .01), although no significant difference was observed in diastolic BP. In contrast, the increase in pulse rate after movement was significantly higher in the young group (4.4 +/- 4.0 vs. 9.0 +/- 4.8 bpm, p < .05). Thus, the fluctuation of the systolic BP was more dependent on physical activity in the older group, whereas PR variations correlated with the physical activity in the young group.

Acceleration↗