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Biomedical subjects

S Hisamichi

Publications and source records attributed to S Hisamichi.

At least 37 records · Page 2Linked to original sources

Determinants of infant feeding method in relation to risk factors for breast cancer.

BACKGROUND: Breastfeeding is considered to be an important factor for maternal and children's health. However, the epidemiological findings related to the effect of breastfeeding on women's health, especially with respect to breast cancer development, are inconsistent. Determinants of infant feeding method may contribute to the inconsistency. METHODS: A total of 24,769 women aged 40-64 in Miyagi Prefecture, Japan, responded to a self-administered questionnaire survey in 1990. Using the data obtained from 22,085 parous women, we calculated odds ratios (ORs) for the choice of "breastfeeding only" during reproductive period. RESULTS: Late age at menarche (> or = 16 years, OR = 1.57) and high body mass index (BMI) at 20 years of age (> or = 24, OR = 1.31) were associated with the choice of breastfeeding only. Late age at birth of first child (> or = 28 years, OR = 0.29), history of breast cancer in mother (OR = 0.68), and high educational level (more than a high school education, OR = 0.53) reduced the possibility of choosing breastfeeding only. CONCLUSION: The results indicate that the choice of infant feeding method is associated with several breast cancer risk factors. Based on this finding, we should construct appropriate breast cancer risk models for parous women and investigate the changes in the effects of breastfeeding and other breast cancer risk factors among these risk models. Especially in a risk model controlling for breastfeeding, the effects of other breast cancer risk factors should be reevaluated. Through comparisons among different risk models, we may find the best-fitted risk model and identify the true effect of breastfeeding.

Adolescent↗

Mortality and cancer incidence in patients with Parkinson's disease.

To investigate the risks of mortality and cancer incidence in Parkinson's disease (PD) we studied the prognosis of 246 PD patients in a community. The cohort of PD patients was identified in 1984, and survival, mortality, relocation, and cancer incidence during 1984-1992 were examined retrospectively in 1994. The risk was measured by a standard effect estimate, i.e., the standardized mortality ratio (SMR) or the standardized incidence ratio (SIR), compared with the rates in the general population. During the observation period 696 person-years in PD men and 1018 person-years in PD women were accumulated, and 49 PD men and 53 PD women died. The risk of mortality in PD was significantly increased in both sexes (SMR: men 1.74, women 1.97). In addition, the risk of cancer incidence was evaluated in 228 patients aged under 80 years; 8 PD men and 7 PD women developed cancer. The risk of overall cancer incidence in PD was less than 1 in either sex, but not significantly. The risk of breast cancer in PD women was significantly increased (SIR: 5.49), but the 95% confidence interval was wide (1.10-16.03). The results indicate that PD patients in a community have a twofold higher risk of mortality, and that PD may be associated with an increased risk of breast cancer in women.

Adult↗

Human G-protein beta3 subunit variant is associated with serum potassium and total cholesterol levels but not with blood pressure.

The activity of a sodium-proton exchanger is enhanced in the patients with essential hypertension and regulated via G-protein, which is a signal transducer between receptors and intracellular effectors. A recent study has revealed that a novel variant (C825T) in exon 10 of the gene encoding the beta3 subunit of heterotrimetric G proteins (GNB3) is a genetic factor predisposing to hypertension in Caucasians. We examined the association between GNB3/ C825T and blood pressure, lipids, electrolytes, and other parameters in a Japanese population. Subjects (n = 352) were selected from the Ohasama Study, the population of which is regarded as from a rural community in Japan. To obtain precise clinical measurements, 24-h ambulatory blood pressure monitoring (ABPM), brain magnetic resonance imaging (MRI), and carotid ultrasonography (CUS) were conducted in this population. In addition, we recruited 762 subjects from outpatients at the Osaka University Medical School to carry out the association study between hypertension and GNB3. The GNB3 genotype distribution did not differ significantly between normotensives and hypertensives in either of the two studies. The T825 allele of GNB3 was not associated with the presence of hypertension, blood pressure level, the number of brain lacunae or carotid wall thickness. However, the serum potassium and total cholesterol levels were significantly higher in subjects with the T allele (P < .005). The T825 allele of GNB3 is associated with increased serum potassium and total cholesterol levels but not with blood pressure in a Japanese population.

Adult↗

Gene polymorphism of the renin-angiotensin system associates with risk for lacunar infarction. The Ohasama study.

The polymorphism of the angiotensin-converting enzyme gene is considered to be associated with increased risk for stroke, but there is a diversity in the results obtained. The genetic involvement of the renin-angiotensin system in stroke also remains unclear. To predict the genetic risk of lacunar infarction, we conducted an association study in an Ohasama population, which is the cohort in a rural region of northern Japan. A total of 134 subjects without major neurological, cardiovascular, or metabolic disorders were recruited. Using brain magnetic resonance imaging, the number of lacunae in each of four brain regions were calculated, and periventricular hyperintensity was classified into five grades. We used the following four candidate gene polymorphisms: angiotensin converting enzyme (ACE)/Insertion(I)-Deletion(D), angiotensinogen (AGT)/M235T, angiotensin II type 1 receptor (AT1)/ A1166C, type 2 receptor (AT2)/C3123A, to examine the association between polymorphisms and the severity of lacunar infarction. AGT/M235T was significantly associated with the number of lacunae in the brain stem, the basal ganglia (P < .05), and whole brain (P < .005) regions. The AT1 polymorphism was also significantly associated with the number of lacunae in the basal ganglia and whole brain regions (P < .05), and with periventricular hyperintensity grade (P < .005) in the younger population. However, ACE and AT2 polymorphisms failed to show an association with either the number of lacunae or the PVH grade. We concluded that AGT and AT1 polymorphisms are independent genetic risk factors for lacunar infarction.

Aged↗

Analysis of biochemical and virological efficacy of human lymphoblastoid interferon (IFN) in patients with compensated type C liver cirrhosis: comparative study between increase in individual IFN dose and prolonging of treatment period, using a multicenter randomized controlled trial.

A controlled trial was conducted to compare the efficacy of interferon (IFN) between two groups of patients with type C liver. Thirty-five patients were randomly assigned to group A (17 patients) or group B (18 patients). The former received 3 megaunits (MU) of human lymphoblastoid IFN six days per week for two weeks, followed by three days per week for 50 weeks; the latter group received 6 MU six days per week for two weeks followed by three days per week for 24 weeks. The percentages of biological sustained responders (B-SR) and virological sustained responders (V-SR) were 29.4 and 23.5%, respectively, in group B, and 17.6% for both in group A. The therapeutic effects were not different between two groups. HCV genotype 2 accounted for significantly higher percentage of B-SR and V-SR (both 57.1%, respectively). These findings indicate that IFN is effective in type C cirrhosis with genotype 2.

Adult↗

Prediction of stroke by ambulatory blood pressure monitoring versus screening blood pressure measurements in a general population: the Ohasama study.

OBJECTIVE: To investigate the association between 24 h, daytime and night-time ambulatory blood pressures and first symptomatic stroke, to compare their predictive powers for stroke with that of casual (screening) blood pressure, and to compare the predictive power for stroke between daytime and night-time blood pressures, in a general population in Ohasama, Japan. DESIGN: A prospective cohort study. SUBJECTS AND METHODS: We obtained ambulatory blood pressure on 1,464 subjects aged > or = 40 years without history of symptomatic stroke, then followed-up their stroke-free survival. There were 74 first symptomatic stroke during the follow-up period (mean = 6.4 years). The prognostic significance of blood pressure for stroke risk was examined by a Cox proportional hazards regression model adjusted for possible confounding factors. RESULTS: The non-parametric and parametric analysis indicated that 24-h, daytime and night-time ambulatory blood pressures were linearly related with stroke risk. The likelihood ratio analysis demonstrated that these ambulatory blood pressures were significantly better related to stroke risk than did screening blood pressure, and that daytime blood pressure better predicted stroke risk than did night-time blood pressure. CONCLUSIONS: The present study which prospectively investigated the relation between ambulatory blood pressure and first symptomatic stroke risk in a general population demonstrated that (i) ambulatory blood pressure values were linearly related to stroke risk; (ii) ambulatory blood pressures had the stronger predictive power for stroke risk than did screening blood pressure; and (iii) daytime blood pressure better related to stroke risk than did night-time blood pressure.

Blood Pressure↗

Japanese individuals do not harbor the T594M mutation but do have the P592S mutation in the C-terminus of the beta-subunit of the epithelial sodium channel: the Ohasama study.

OBJECTIVE: To assess the implications of polymorphisms of the amiloride-sensitive epithelial sodium channel in essential hypertension in the Japanese population by determining the incidence of the T594M mutation in the , subunit of the epithelial sodium channel, and by screening the C-terminus of the epithelial sodium channel. METHODS: Single-strand confirmational polymorphism (SSCP) analysis using two sets of primers which cover the last two-thirds of the last exon coding the B epithelial sodium channel and modification of a specific enzyme restriction site (NlaIII) for the T594M mutation were performed on 803 Japanese subjects. They were randomly selected from the study participants representative of a general population of Ohasama, Japan, who measured their home blood pressure. Polymerase chain reaction (PCR) products presenting a shift in SSCP gel, as well as controls, were directly sequenced by autoanalyser to identify the mutation. RESULTS: SSCP analysis identified altered migration in five subjects. Four SSCP variants found by sequencing were heterogeneous for the P592S (CCT to TCT) mutation conserving the PY motif, although it was not significantly associated with either home or casual blood pressure values. The resting polymorphism was at codon Thr 594, leading to no change in the amino acid sequence (ACG to ACA). None of the PCR products were modified by NlaIII, indicating the absence of the T594M mutation. CONCLUSIONS: The epithelial sodium channel variants at the C-terminus are not involved in the common form of essential hypertension in Japanese.

Adult↗

Prognostic significance of blood pressure and heart rate variabilities: the Ohasama study.

To investigate the association between cardiovascular mortality and short-term variabilities in blood pressure and heart rate, we performed a long-term prospective study of ambulatory blood pressure monitoring in Ohasama, Japan, starting in 1987. We obtained ambulatory blood pressure and heart rate in 1542 subjects >/=40 years of age. Blood pressure and heart rate variabilities were estimated as a standard deviation measured every 30 minutes by ambulatory monitoring. There were 67 cardiovascular deaths during the follow-up period (mean=8.5 years). The Cox proportional hazards model, adjusted for possible confounding factors, demonstrated a significant increase in cardiovascular mortality, with an increase in daytime systolic ambulatory blood pressure variability. A similar trend was observed in daytime diastolic and nighttime ambulatory blood pressures. Cardiovascular mortality rate increased linearly, with a decrease in daytime heart rate variability. Subjects in whom the daytime systolic ambulatory blood pressure variability was larger than third quintile and the daytime heart rate variability was lower than the mean-SD were at extremely high risk of cardiovascular mortality. The blood pressure and heart rate variabilities obtained every 30 minutes by ambulatory blood pressure monitoring were independent predictors for cardiovascular mortality in the general population.

Aged↗

Relationship between health practices and education level in the rural Japanese population.

Past studies in Europe and the USA have found that people with higher education levels have better health practices. The aim of this study was to examine the association between health practices and education level among people in a rural Japanese community. Data were derived from the Ohsaki National Health Insurance Cohort Study, which has been following 52,029 NHI beneficiaries, aged 40 to 79 years, in Miyagi Prefecture, Japan. The relationship between education level and seven health indices (smoking, drinking, body mass index, sleeping, exercise, breakfast, and snacks) was analyzed. Higher education was associated with shorter sleeping hours for both men and women, and lower BMI for women. In age groups younger than 70 years, people with higher education tended to exercise more. Smoking for women, alcohol consumption, and a Health Practices Index were not related to education levels. These results are different from those from Europe and the USA. This study suggest that the relationship between health practices and education level is weaker in Japan than in Europe and the USA.

Adult↗

Randomized controlled trial of exercise training for older people (Sendai Silver Center Trial; SSCT): study design and primary outcome.

Physical exercise is expected to improve and maintain physical function in older people, thus promoting health and preventing or postponing the onset of disability in later life. The Sendai Silver Center Trial (SSCT) was a randomized controlled trial designed to evaluate the efficacy of exercise training among healthy free-living older people. Sixty-five eligible participants, aged from 60 to 81 years, were randomly allocated to an exercise group or a control group. The subjects in the exercise group were asked to attend training classes at the Sendai Silver Center, a municipal health and welfare facility in the center of Sendai City, at least twice a week for 25 weeks. Each training class, lasting two hours, started with a warm-up session, followed by an endurance session with a bicycle ergometer, and a resistance exercise training session using rubber films, and ended with a cool-down session. The subjects in the control group were asked to attend recreational classes at the Center twice a month. There were no drop-outs or accidents during the intervention. Comparison of maximum oxygen consumption (VO2max) before and after the 25-week intervention revealed a significant increase in the exercise group (2.1 ml/kg/min) but no significant change in the control group. Our result is equivalent to the participants becoming younger in aerobic capacity by five years after six months of exercise training.

Aged↗

Increased acute myocardial infarction mortality following the 1995 Great Hanshin-Awaji earthquake in Japan.

BACKGROUND: This study examined the factors affecting mortality from acute myocardial infarction (AMI) following the 1995 Great Hanshin-Awaji earthquake. METHODS: We examined the death certificates of all decedents between January 1994 and December 1996 in 16 municipalities, which covered most of the area affected by the 1995 Great Hanshin-Awaji earthquake. We analysed the extent and duration of the increased mortality from AMI. The standardized mortality ratio (SMR) of AMI was calculated weekly after the earthquake, taking the number of AMI deaths during the same period in 1994 as a reference. The main outcome measures were the number of deaths from AMI (ICD-9 410; ICD-10 I21, I22) in the study area before and after the earthquake, and the weekly SMR after the earthquake. RESULTS: A significant increase in mortality from AMI in the study area as a whole continued for about 8 weeks after the earthquake. There was wide variation amongst the regions with respect to the extent and duration of the increased mortality from AMI. The SMR of AMI showed a positive relationship with the percentage of houses which were completely destroyed, and was almost significant (r = 0.530, P = 0.062). CONCLUSIONS: The duration of increased cardiac mortality after the 1995 Great Hanshin-Awaji earthquake was longer than seen with previous earthquakes. Further analysis to identify the factors affecting cardiac mortality is needed so that we may reduce adverse health effects during the recovery stage following natural disaster.

Adult↗

Inter- and intra-individual variation of food and nutrient consumption in a rural Japanese population.

OBJECTIVES: To determine the relative contribution of intra- and inter-individual variation in the consumption of foods and nutrients. DESIGN: Cross-sectional study. SETTING: Two rural towns in the Miyagi Prefecture, a northeastern part of Japan. SUBJECTS: Fifty-nine men and sixty women. METHODS: Four 3-d food records were collected in four seasons within a year. The total variance in the consumption of 15 nutrient variables and 16 food groups was partitioned by analysis of variance into its inter- and intra-individual components, separately for men and women. RESULTS: The ratio of the intra- to inter-individual variance was larger than unity in 87% (13/15) of the nutrients in men and 100% (15/15) in women. The ratio was largest for retinol (52.9 in men and infinity in women) and smallest for carbohydrates (0.8 in men and 1.5 in women). The ratio was larger than unity in 88% (14/16) of the food groups in men and 94% (15/16) in women, which was smallest for cereals (0.6 in men and 0.9 in women). CONCLUSIONS: The results were consistent with previous western studies in that intra-individual variation was generally larger than inter-individual variation for the consumption of both foods and nutrients. SPONSORSHIP: This study was supported in part by Grants-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture (09470106) and by Health Sciences Research Grants for Research on Health Services (H10-25) from the Ministry of Health and Welfare in Japan.

Aged↗

Trends in dementia-free life expectancy among elderly members of a large health maintenance organization.

BACKGROUND: This study examined the secular trends of life expectancy without dementia among elderly American members of a health maintenance organization, and observed if an increased life expectancy is accompanied by an increase in the duration of life with dementia. METHODS: The data derived from two chronological 9-year prospective cohort studies of members of the Kaiser Permanente Medical Care Program of Northern California. The first and second cohorts included 2,702 and 2,926 people aged > or =65 years free from dementia at baseline. Life expectancy without dementia or dementia-free life expectancy (DemFLE) is defined as the average number of years a person is expected to live without dementia. Total life expectancy is equal to the sum of DemFLE and life expectancy with dementia. Estimations of DemFLE were based on mortality data and incidence of dementia, using double-decrement life tables. RESULTS: Between the first and second cohorts, all-cause mortality rates declined, while the incidence of dementia remained constant in both men and women. Among the males, total life expectancy increased at a higher rate than DemFLE. Consequently, the duration of life with dementia was extended in the second cohort. Conversely, among the females DemFLE increased at a higher rate than total life expectancy, thus the duration of life with dementia decreased in the second cohort. The median age of dementia onset was postponed by 2-3 years in the second cohort for females, and did not show any specific difference between the two cohorts in males. CONCLUSION: The trends of health expectancies suggest an extension of the duration of life with dementia for males and a compression of dementia for females. A decreased incidence of risk factors for dementia among females in the second cohort such as stroke may explain these trends.

Age Distribution↗