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Biomedical subjects

K Kuramoto

Publications and source records attributed to K Kuramoto.

At least 73 records · Page 4Linked to original sources
PubMed1993

[A case of primary systemic amyloidosis with skeletal muscle atrophy and congestive heart failure].

A 77-year-old male had been noticing progressive weakness of the legs for three years. By the age of 75 he had difficulty in climbing stairs. On admission, serum level of CPK was moderately high. There were weakness and atrophy of the proximal muscles. Deep tendon reflexes were depressed. Sensation was normal. The electromyogram and the biopsy of the femoral quadriceps muscles showed nonspecific changes. In 1989, he developed difficulty in walking and had congestive heart failure. On the second admission, moist rales were heard over the chest, and pitting edema was present in the lower extremities. The chest roentgenogram showed a cardiothoracic ratio of 63% and bilateral pleural effusion. The electrocardiogram showed atrial flutter with 2:1 conduction, QS in V1-3, rS in V4, and ST depression and T inversion in V5,6. The echocardiogram revealed a thick left ventricular wall and impaired left ventricular contraction (EF 22%). Macroglossia, hepatosplenomegaly and renal dysfunction were not noted. Congestive heart failure progressed and he suddenly died of ventricular tachycardia in December 1989. At autopsy, skeletal muscle fibers varied in size and showed fiber splitting. A cellular infiltration was observed in the stroma. Amyloid deposit was positively stained with Congo red. The heart weight was 570 g with marked left ventricular hypertrophy and moderate bilateral atrial dilatation. In both atria and ventricles, extensive amyloid deposition was found around myocardial fibers as well as in perivascular spaces. Amyloid was present also in the liver, the kidneys, the gastrointestinal tracts, and the other organs.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

[Prevalence, rate of correct clinical diagnosis and mortality of cancer in 4,894 elderly autopsy cases].

The prevalence, rate of correct clinical diagnosis and mortality of cancer were analyzed in 4,894 consecutive autopsies at the Tokyo Metropolitan Geriatric Hospital from 1972 to 1990. average age and standard deviation of patients was 78.1 +/- 9.1 years. Cancer was found in 45.5% of patients of 60 years and over, and in 49.1% in men and 41.9% in women (p < 0.001). Cancer prevalence decreased with advance in age; 50.0% in the sixties, 47.9% in the seventies, 43.2% in the eighties and 39.3% in the nineties and over. Multiple cancer was found in approximately 12% of patients of 70 years and over. The top three cancer incidences were gastric cancer, 15.0%, lung cancer, 10.7% and colon cancer, 5.9% in both genders. In men, prostate cancer was next common, followed in orderly hepatic cancer, esophageal cancer, gall bladder-bile duct cancer, pancreas cancer, renal cancer and urinary bladder cancer. In women, the following order of frequency was gall bladder-bile duct cancer, uterus cancer, pancreas cancer, hepatic cancer, breast cancer, thyroid cancer, esophageal cancer, renal cancer and urinary bladder cancer. The prevalence of gastric cancer, lung cancer, hepatic cancer and esophageal cancer was significantly higher in men, while that of gall bladder-bile duct cancer was higher in women. The age-related tendencies varied among cancers of different organs. Gastric cancer increased up to the sixties in men and up to the seventies in women and leveled off after those ages. Lung cancer revealed peak prevalence in the sixties and seventies and decreased after the age of eighty.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

[An elderly case of supernormal conduction in the posterior division of the left bundle branch].

An electrophysiologic study was performed in a 95-year-old man with bifascicular block (right bundle branch block and left anterior hemiblock). During sinus rhythm (AA interval = 980 ms), every sinus beat was conducted to the ventricle. The AH interval was 130 ms and HV interval was 50 ms. A programmed premature atrial stimulation was performed after 8 paced beats at a slightly shorter cycle length than the sinus cycle length (900 ms). As the atrial coupling interval was shortened, the H1H2 interval also shortened. At an H1H2 interval of 680 ms the premature atrial beat was blocked distal to the recording site of the His potential. The block persisted up to an H1H2 interval of 560 ms. AV conduction resumed paradoxically when the H1H2 interval was further shortened to intervals lasting 540-490 ms. During this period the H2V2 interval was 50 ms. At still shorter H1H2 intervals, H2 was again blocked. The H2V2 intervals during this phase of improved conduction were unchanged compared with those of other conducted beats. Therefore normalization due to the gap phenomenon could be ruled out, and the improved conduction could be explained by a phenomenon of supernormal conduction in the posterior division of left bundle branch.

Aged↗
PubMed1993

[Clinical evaluation of finger blood pressure measurement devices for home-use].

We evaluated the accuracy of two types of finger blood pressure (BP) measurement devices for home-use (EW276 H, NATIONAL Ltd. and HEM 804F, OMRON Ltd.) by comparing BP values with upper-arm BP measured with a standard mercury column sphygmomanometer in 28 elderly subjects (13 Hypertensives and 15 normotensives). The correlation coefficient of systolic BP value and that obtained by each method was R2 = 0.5 for EW 276H and R2 = 0.6 for HEM 804F. The higher the systolic BP, the greater was the difference between the upper-arm and finger BP values. The magnitude of the difference between finger and upper-arm values for systolic BP did not correlate with pulse wave velocity. An underestimation of the finger BP device in systolic BP was 23.8 mmHg in hypertensives and 7.6 mmHg in normotensives for the EW 276H, and 15.3 and 3.5 mmHg, respectively for the HEM 804F. This study demonstrated a large difference between the finger BP value measured with the home-use devices and upper-arm BP value measured with a standard mercury sphygmonanometer in elderly hypertensive patients. The difference may be due not only to atherosclerotic change, but also to methodological factors related to finger BP measurement.

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PubMed1993

[Age and gender difference in circadian rhythm in blood pressure].

In order to evaluate the effect of gender and aging on the diurnal rhythm of blood pressure (BP), we performed ambulatory BP monitoring in 267 normotensive volunteers (mean age +/- SD 52.1 +/- 24.6 years, range 16-93 years, 114 men, 153 women). Ambulatory 24-hour BP was recorded every 30 minutes with an oscillometric method by ABPM630 (Nippon-Kolin, Japan). Circadian rhythm was determined by fitting the 24-hour cosine function curve. Subjects were divided into three age groups, consisting of the Y group (age < 30), M group (age > or = 30 but < 60), and E group (age > or = 60). Highest normal values of the 24-hour mean BP (90 percentile of the values) were 126/75 mmHg in the Y group, 126/76 mmHg in the M group, and 154/85 mmHg in the E group in men. They were 117/67 mmHg, 125/77 mmHg 151/79 mmHg respectively in women. The MESOR of SBP increased with age in women, though it was significantly higher only in the E group among men. The amplitude of SBP decreased with age significantly only in men. The acrophase of SBP shifted to an earlier time of day with aging in both men and women. The trends in the circadian rhythm of DBP with age were similar to those of SBP. In conclusion, the circadian rhythm of blood pressure varies with gender and aging. The 24-hour blood pressure values should be considered with evaluating sex-age matched reference values.

Adult↗
PubMed1993

[The relation between blood pressure variation and daily physical activity in early morning surge in blood pressure].

Morning rise in blood pressure (morning surge; MS) has been shown to be associated with the occurrence of myocardial ischemic events and stroke. This study aimed to elucidate the incidence and the mechanism of MS in hypertensive patients (HT). We monitored ambulatory blood pressure (BP) and physical activity in 68 untreated HTs using TM2421 (A & D Co. Ltd.) and ACTIVETRACER (GMS Ltd.) for detection of MS. MS was defined as a rise in BP > 50 mmHg (90% tile of 35 normotensives) during early morning (4:00 to 9:00 A.M.) compared with the lowest basal BP at night. MS was seen in 41 patients (52.6%) and was classified into two groups; MS1: BP rose steeply after waking up (27 patients) and MS2: BP started to rise gradually during sleep (14 patients). The mean age of MS1 was significantly higher than that of MS2 (72 vs. 62 years, p < 0.01). BP reached its basal value earlier in MS2 than in MS1 at night though the basal BP values were comparable between the two groups. Mean 24-hour BP and physical activity were similar between the two groups, though significantly higher incidence of cases with a correlation between SBP and activity was seen in MS1. In conclusion, there are two types of MS, the mechanisms of which may differ. MS occurring immediately after waking up was more common in older HTs, and possibly was related to augmented arousal response in BP, while MS beginning gradually during sleep was more common in younger HTs and was characterized by reaching basal BP earlier at night.

Activities of Daily Living↗
PubMed1993

[Long-term follow-up study after permanent pacemaker implantation in patients aged 60 years or over with sick sinus syndrome].

Ninety-five patients aged 60 years or over with a permanent pacemaker implanted for sick sinus syndrome were divided into two groups: 32 patients with physiological pacing (group P) and 63 patients with ventricular pacing (group V). The mean follow-up period was 45.0 +/- 36.6 months in group P and 50.3 +/- 37.8 months in group V. Paroxysmal atrial fibrillation (Af) occurred in 28% of group P and 71% of group V (p < 0.05). The incidence of stable Af was also lower in group P than in group V (9% vs. 30%, p < 0.05). None of group P with only bradyarrhythmia had stable Af. However, 6 of 21 patients (29%) in group V with bradyarrhythmia showed stable Af. There was no significant difference in stable Af between group P with bradycardia-tachycardia syndrome (BTS) and group V with BTS (19% vs. 31%). A lower incidence of embolic events was also observed in group P (3% vs. 25%, p < 0.05). Nine of 16 patients with embolic events in group V died of complications following embolism (8 patients; cerebral embolism, one patients: renal and superior mesenteric arterial embolism). The survival rates at 5 and 10 years were 80% and 69%, respectively, for group P and 56% and 33% for group V (p < 0.01). Thus, with regard to permanent pacing for patients with sick sinus syndrome, physiological pacing should be selected for control of morbidity and total mortality.

Aged↗
PubMed1992

Diminished nocturnal decline in blood pressure in elderly hypertensive patients with left ventricular hypertrophy.

To assess the circadian blood pressure (BP) changes in elderly hypertensive patients with left ventricular hypertrophy (LVH), the ambulatory BP was measured noninvasively every 30 minutes for 24 hours in those patients with LVH (n = 15) and without LVH (n = 23), and in normotensive elderly subjects (n = 11). Although the daytime systolic BP (SBP) was comparable in the two hypertensive groups, the nighttime SBP in patients with LVH tended to be higher than in patients without LVH (149.0 +/- 15.1 versus 138.4 +/- 20.1 mm Hg, p less than 0.10). The LV mass index correlated significantly with the nighttime SBP (r = 0.43, p less than 0.01), but not with the daytime SBP (r = 0.24, ns), with clinic SBP (r = 0.14, p = ns) or the SBP after handgrip exercise (r = 0.31, p = ns). The difference in the systolic BP between daytime and nighttime (D-N SBP) in patients with LVH (2.8 +/- 9.4 mm Hg) was significantly less than that in patients without LVH (12.8 +/- 16.0 mm Hg) (p less than 0.02). In addition, the D-N SBP correlated inversely with the left ventricular mass index (r = -0.33, p less than 0.05). It was concluded that hypertension in the elderly with LVH was associated with a diminished nocturnal decline in blood pressure.

Aged↗
PubMed1992

Lifetime data analysis of disease and aging by the Weibull probability distribution.

We applied the Weibull distribution to the life-table and age-patterns of diseases in Japan. The life-table follows a composite Weibull distribution composed of initial failure and two stage wear-out failure periods. The extension of lifespan during the past century is manifested as increases in the scale parameters in all three periods and the shape parameters in the wear-out periods with female predominancy. The shape parameters of diseases show time-independent sex-dependent specific values. When consistent changes are observed, such as increases in the shape parameters of tuberculosis and pneumonia, legitimate causes such as prevention and repair at the societal and medical level are present. Cancer and arteriosclerosis share a common range of shape parameters suggesting analogous underlying biological processes. An analysis of the epidemiology of human aging and disease by the Weibull distribution discloses intrinsic properties of man as a biological organization as well as a societal presence.

Adolescent↗
PubMed1992

The cardiac functional reserve in elderly hypertensive patients with abnormal diurnal change in blood pressure.

OBJECTIVE: To evaluate the left ventricular function of hypertensive patients with abnormal diurnal change in blood pressure. DESIGN: We compared left ventricular structural and functional characteristics between hypertensive patients with a normal diurnal change in blood pressure (H2 group) and those with a nocturnal blood pressure increment (H1 group) using echocardiography. METHODS: The study group consisted of 36 hypertensives and 16 normotensives whose 24-h ambulatory blood pressure monitorings were measured non-invasively. The hypertensive group was subdivided into the H1 group, consisting of 11 patients (76 +/- 7 years), and the H2 group with 25 patients (73 +/- 7 years). The normotensive control group had a mean age of 73 +/- 6 years. Echocardiographic examinations were performed before and at the end of isometric exercise (handgrip for 3 min) and isoproterenol infusion (0.02 micrograms/kg per min for 5 min). RESULTS: The left ventricular mass index in the H1 group was significantly greater than in the H2 or control group. Left ventricular fractional shortening (LVFS) at rest in the H1 group was also significantly greater than in the other two groups. However, the peak late: early diastolic filling ratio, which indicated diastolic function, significantly deteriorated in the H1 group compared with the H2 and control groups. Furthermore, changes in LVFS after isometric exercise in the H1 group were more suppressed than in the H2 or control group. In addition, a significantly lower increment in LVFS after isoproterenol was observed in the H1 group compared with the H2 or control group. CONCLUSION: The H1 group had greater left ventricular mass and impaired left ventricular functional reserve than the H2 group.

Aged↗
PubMed1992

Possible regulation of caffeine-induced intracellular Ca2+ mobilization by intracellular free Na+.

To gain some understanding of the regulatory mechanism involved in caffeine-induced Ca2+ release in adrenal chromaffin cells, we took advantage of the paradoxical observation that removal of divalent cations potentiated the secretory response to caffeine. We measured the concentration of cytosolic free Ca2+ ([Ca]in) in isolated cat chromaffin cells, by fura-2 microfluorometry, to see whether there was any correlation between the secretory response and the rise in [Ca]in. The caffeine-induced [Ca]in rise and catecholamine secretion were increased by treatment of cells with a divalent cation-deficient solution. These potentiated responses were strongly inhibited either by pretreatment with ryanodine, by the reduction of the external Na+ concentration, or by the addition of Ca2+ channel blockers. Removal of divalent cations caused a large rise in the cytosolic free Na+ concentration ([Na]in), which was measured using SBFI microfluorometry. This rise in [Na]in was reduced either by adding Ca2+ channel blockers or by reducing the external Na+ concentration. These results show a good correlation between caffeine-induced Ca2+ release and [Na]in at the time of stimulation, suggesting that caffeine-induced Ca2+ release is regulated by [Na]in.

Animals↗
PubMed1992

[Age-related non-tumorous lesions in SPF C57BL/6 mice with special reference to amyloidosis].

Non-tumorous pathological changes in C57BL/6 CrSlc mice, which were reared under a barrier system and died spontaneously, were examined. At 3 months intervals 125 to 209 mice were purchased at 4 weeks of age and raised for the supply of aged animals. A large portion of the mice were used for various experiments between 3 and 30 months of age, while not a small number died spontaneously and were autopsied. The major non-neoplastic lesion was amyloidosis, with incidence of 55.5% and 74.4% for the autopsied female and male, respectively. The organs involved were the liver, kidneys, spleen, adrenal glands, ileum, heart and lungs. Skin ulceration and its scar, cerebral vascular calcification, glomerulosclerosis and sepsis in both sexes, distension of the seminal vesicles in males, fibroblast growth of the adrenal glands in females were commonly found. Incidence of spontaneous neoplastic lesions was 69.7% and 55.1% for the female and male, respectively.

Aging↗
PubMed1992

[Age-related incidence of spontaneous tumors in SPF C57BL/6 and BDF1 mice].

Incidence of spontaneous tumors in C57BL/6 NCrj (CR), C5BL/6 CrSlc (SL) and B 6 Crj x DBA/2 NCrj F1 (BD) mice, which were reared under a barrier system and died natural death, were examined. Cohorts of mice in 200 to 300 each were purchased at 4 weeks of age and raised under SPF conditions. A large portion of the mice were used for various experiments between 3 and 30 months old while not a small number died before use and were autopsied. Median survival periods of the female and male were estimated at 697 and 680 days for CR, 764 and 806 days for SL and 866 and 929 days for BD, respectively. Incidence of spontaneous neoplastic lesions in the autopsied animals were 77.4% and 79.2% of 535 female and 590 male CR, 69.7% and 55.1% of 502 female and 463 male SL, and 75.8% and 78.0% of 298 female and 346 male BD, respectively. In CR, histiocytic sarcoma was the most predominant tumor, accounting for 72.1% of all tumors. In SL, malignant lymphoma was the most prevailing, forming 62.3%, and, in male BD, hepatocellular carcinoma was the most frequent, accounting for 41.8% of all tumors.

Aging↗
PubMed1992

[Effect of antiplatelet and anticoagulant therapy on secondary prevention and long-term prognosis after acute myocardial infarction in aged patients].

The long-term efficacy and side effects of antiplatelet and anticoagulant therapy for secondary prevention after the first acute myocardial infarction (AMI) were retrospectively assessed in 133 patients over 60 years of age during a mean follow-up period of 36.6 months. Seventy five patients received antiplatelet and anticoagulant therapy (group 1) and 58 patients did not (group 2). In group 1 patients, 54, 12 and 9 patients received ticlopidine, aspirin and warfarin, respectively. Mean age, sex ratio, site of AMI, max CPK value and left ventricular ejection fraction in the convalescent phase did not differ between the two groups. There were no differences between the two groups in terms of the number and kind of combination drugs such as nitrate, beta-blocker and Ca antagonist. During the follow-up period 40 patients died; 18 patients (45%) suffered cardiac death and 22 patients (55%) experienced non-cardiac death. Nineteen patients had recurrent MI and 37 patients had cardiac events which were defined in total as cardiac death, recurrent MI and unstable angina pectoris. The total mortality rate and rate of recurrent MI based on the life time table method were significantly lower in group 1 than in group 2 by the generalized Wilcoxon test. The cumulative total mortality rate in the fifth year was 24.2% in group 1 and 49% in group 2. The cumulative rate for recurrent MI in the fifth year was 7.4% in group 1 and 27.5% in group 2 (p less than 0.05). However, the rate of cardiac events did not differ between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

[Acute hemodynamic effects of intravenous bolus injection of isosorbide dinitrate in aged patients with congestive heart failure].

In order to investigate whether intravenous bolus injection of isosorbide dinitrate (ISDN) is a safe and efficient therapy in aged patients with congestive heart failure, we studied acute hemodynamic effects in 11 patients. Peak effects on preload were observed after 5 to 10 minutes of bolus injection and unloading effects continued effectively for 60 minutes. At peak effect, pulmonary systolic pressure decreased from 50.2 +/- 2.6 to 36.2 +/- 2.6 mmHg (-28.5%, p less than 0.01) and pulmonary end diastolic pressure decreased from 25.0 +/- 2.2 to 18.5 +/- 2.1 mmHg (-26.0%, p less than 0.01). Mean pulmonary artery wedge pressure decreased from 23.4 +/- 2.2 to 16.0 +/- 2.1 mmHg (-31.6%, p less than 0.01). Mean right atrial pressure decreased from 10.5 +/- 1.8 to 7.4 +/- 2.0 mmHg (-29.5%, p less than 0.01). Blood pressure, heart rate, cardiac index, systemic and pulmonary vascular resistance showed no significant changes. Thus, intravenous bolus injection of ISDN showed a potent vasodilator effects on preload, and may be a safe and useful treatment for aged patients with acute congestive heart failure.

Aged↗
PubMed1992

[Congestive heart failure in elderly readmitted patients].

The clinical features of congestive heart failure in the elderly were investigated in 104 patients (57 males, 47 females, mean age of 79.2). Patients were divided into two subgroups, the readmission group, 33 patients who were readmitted within 6 months after discharge, and the non-readmission group. Chief complaints were dyspnea, edema, chest pain, loss of appetite, chest compression, and palpitation. Heart failure was caused by infection, myocardial ischemia, arrhythmia, inappropriate drug usage including poor drug compliance, the use of beta-blockers, excessive intake of sodium, and anemia. Careful use of drug was essential especially in the readmission group. Major underlying heart disease were ischemic heart disease (39.4%), valvular disease (26.9%), hypertensive heart disease (9.6%), with cardiomyopathy, congenital heart disease seen in the minority. There was no statistically significant difference in underlying heart diseases between the two groups. Supraventricular arrhythmias such as atrial fibrillations, paroxysmal atrial fibrillations, paroxysmal supraventricular tachycardias, and premature atrial contractions were noted in 85.3% of the cases. Drugs for treatment were diuretics, digitalis, isosorbide dinitrate, calcium antagonists. ACE inhibitors and alpha-blockers were also used, showing that vasodilators were more extensively used than before. The major complications were hypertension (39.4%), renal dysfunction (27.9%), cerebrovascular disease (26.9%), diabetes mellitus (16.5%), arteriosclerosis obliterans (7.7%). Renal dysfunction, arteriosclerosis obliterans was seen significantly more frequently in the readmission group. The prognosis at one year after admission was significantly worse in the readmission group. In summary, the major underlying diseases were ischemic heart disease, valvular disease, and hypertensive heart disease. Ischemic heart disease was seen more frequently than in previous investigations at our hospital.(ABSTRACT TRUNCATED AT 250 WORDS)

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