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Biomedical subjects

S Iwao

Publications and source records attributed to S Iwao.

At least 19 recordsLinked to original sources
PubMed2005

Differences in the relationship between lipid CHD risk factors and body composition in Caucasians and Japanese.

OBJECTIVES: To examine differences in the relationship between fat distribution and lipid coronary risk factors in Caucasian and Japanese population and further to determine whether the cut-points for body mass index (BMI) and waist circumference (WC) proposed by WHO and NHLBI are applicable to Japanese population as a predictor of a lipid risk factor abnormality or not. RESEARCH METHODS AND PROCEDURES: Subjects were 895 participants of the Baltimore Longitudinal Study of Aging in the US (BLSA) and 1705 participants of the Longitudinal Study of Aging by the National Institutes for Longevity Science in Japan (NILS-LSA). Subjects were divided into four demographic groups as younger (age<65 y) men and women, and older (age> or =65 y) men and women. Blood total cholesterol, triglycerides, LDL- and HDL-cholesterol and anthropometry were measured. Regression coefficients of BMI and WC on risk factors, sensitivity and specificity of the BMI and WC cut-points for blood lipid abnormality, and mean values of blood lipids at BMI or WC cut-points were computed in both populations. RESULTS: Height, weight, WC and BMI were significantly greater in the BLSA than those in the NILS-LSA subjects. Total cholesterol, HDL- and LDL-cholesterol were significantly greater in the NILS-LSA than in the BLSA subjects. Sensitivities of BMI and WC cut-points were much lower in the NILS-LSA than in the BLSA subjects. Specificities of BMI and WC cut-points were higher in the NILS-LSA than in the BLSA subjects. Mean values of triglycerides, total cholesterol, HDL- and LDL-cholesterol at BMI=25 were significantly greater in the NILS-LSA than in the BLSA subjects. At the WC cut-point (94 cm for men, 80 cm for women), mean values of all lipids were significantly greater in the NILS-LSA than in the BLSA subjects with the exception of triglycerides in younger women. CONCLUSIONS: The Japanese subjects have smaller BMI and WC, worse total and LDL-cholesterol levels and better HDL-cholesterol levels compared to Caucasians. Sensitivities of BMI and WC for predicting lipid risk factor abnormality are much lower in Japanese. The cut-points for BMI and WC proposed by WHO and NHLBI may be too high for predicting an abnormality in triglycerides, total and LDL-cholesterol in Japanese. For detecting an abnormal HDL-cholesterol level, the BMI and WC cut-points may not be as beneficial for the Japanese population as for Caucasians.

Adult↗
PubMed2001

Does waist circumference add to the predictive power of the body mass index for coronary risk?

OBJECTIVES: To examine the power of the combined measurements of body mass index (BMI) and waist circumference (WC) for the prediction of abnormality in coronary heart disease risk factors and to determine whether the additional measurement of WC is predictive in older men and women. RESEARCH METHODS AND PROCEDURES: 1190 men and 751 women of the Baltimore Longitudinal Study of Aging were dichotomized into younger (<65 years) and older (65+ years) age groups. Coronary risk factors in the realms of glucose/insulin metabolism, blood pressure, and plasma lipids were assessed. The relationship of BMI and WC, singly and combined, to 10 risk factors for coronary heart disease was examined. RESULTS: In younger and older men and women, BMI and WC are highly correlated (0.84 to 0.88). BMI and WC are also significantly correlated to all 10 coronary risk factors in younger men and women and to 8 of the 10 in the older men and women. Both partial correlation and logistic regression analyses revealed a modest but significant improvement in the prediction of coronary risk in younger men and women by WC after controlling for the level of BMI. There was no improvement in the older subjects. DISCUSSION: WC adds only modestly to the prediction of coronary risk in younger subjects once BMI is known, and adds nothing to the production of risk in older subjects.

Adolescent↗
PubMed2000

A test of recently proposed BMI standards with respect to old age.

The purpose of this study was to investigate the effects of age on the relationship between BMI and multiple coronary risk factors, and to determine whether the BMI classification by NHLBI and WHO is applicable as a predictor of coronary risk factors in older (>65 years) as well as in younger (<65 years) men and women. Effects of age on ten coronary risk factors were examined. Sex differences in the slopes of BMI on risk factors were compared between younger and older subjects in order to examine the effects of age on these relationships. The frequency of risk factor abnormality in individual BMI groups (18.5-24.9, 25.0-29.9, 30.0+) was examined for four age-sex groups. The significance of an age group-BMI interaction term was tested by the logistic regression model to see whether there is a significant difference in the relationship between BMI and the individual risk factor abnormalities between younger and older subjects. Older subjects had significantly higher values for most risk factors than younger subjects. The slopes of BMI on risk factors were different between younger and older subjects for fasting glucose, total, HDL- and LDL-cholesterol in men, and for diastolic blood pressure, total and LDL-cholesterol in women. The proportion of subjects with abnormal risk factor levels in each of the three BMI groups was higher in older than in younger subjects for most risk factors. There was generally a progressive worsening of the risk factor levels with increasing BMI in both age groups. There was no consistent age difference in the relationship between BMI groups and the frequency of risk factor abnormality. We conclude that, although age increases the frequency of most cardiovascular risk factor abnormalities, in general, it does not affect the trend of the relationship between the risk factors and the normal, overweight and obese BMI groups defined by NHLBI and WHO. Therefore, these BMI categories are applicable as predictors of risk factor levels in older as well as in younger men and women.

Adult↗
PubMed2000

Relocation of a cytoplasmic yeast linear plasmid to the nucleus is associated with circularization via nonhomologous recombination involving inverted terminal repeats.

The linear plasmid pCLU1 from the yeast Kluyveromyces lactis normally replicates in the cytoplasm, with the aid of the helper linear plasmid pGKL2, using terminal protein (TP) as a primer. However, it relocates to the nucleus when selection is applied for the expression of a plasmid-borne nuclear marker. Migration to the nucleus occurred in K. lactis at a frequency of about 10(-3)/cell ten or more times higher than the rate observed in Saccharomyces cerevisiae. The nuclear plasmids existed only in a circularized form in K. lactis, while in S. cerevisiae a telomere-associated linear form is also found. Sequence analysis showed that circularization in K. lactis was caused by non-homologous recombination between the inverted terminal repeat (ITR) at the ends of the linear form and non-specific internal target sites in pCLU1. No sequence similarity existed among the junction sites, indicating that the free ITR end plays a crucial role in circularization. In S. cerevisiae, circular plasmids were generated not only by nonhomologous recombination, but also by homologous recombination between short direct repeats within pCLU1. Circularization via the ITR end was observed independently of RAD52 activity. Sequences highly homologous to ARS core elements, 5'-ATTTATTGTTTT-3' for K. lactis and 5'-(A/T)TTTAT(T/G)TTT(A/T)-3' for S. cerevisiae, were detected at multiple sites in the nuclear forms of the plasmids.

Base Sequence↗
PubMed2000

Effect of aging on the relationship between multiple risk factors and waist circumference.

OBJECTIVE: To examine the relationship between various coronary risk factors and the different levels of fat distribution in younger (<65 years) and older (> or = 65 years) men and women, using the classifications proposed by the National Heart, Lung and Blood Institute (NHLBI) and the World Health Organization (WHO). DESIGN: Cross-sectional study of subjects enrolled in the Baltimore Longitudinal Study of Aging. MEASUREMENTS: Systolic blood pressure, diastolic blood pressure, fasting glucose, 2-hour glucose, fasting insulin, homeostasis model assessment insulin resistance (HOMAIR), triglyceride, total cholesterol, high-density lipoprotein (HDL)-cholesterol, and low-density lipoprotein (LDL)-cholesterol were measured as risk factors. The proportion of subjects with abnormal risk factor levels by waist circumference classifications was determined in the age and gender subgroups. RESULTS: There were significant adverse effects of age per se on all risk factors with the exception of fasting insulin and HOMAIR in both men and women, total cholesterol in men, and diastolic blood pressure in women. HDL-cholesterol was higher in older subjects. There were significant correlations between waist circumference and all of the risk factors in the younger group. Waist circumference did not have a significant correlation with total cholesterol in older men, or with total cholesterol and LDL-cholesterol in older women. The proportion of subjects with an abnormal risk factor level increased with increasing waist circumference for most risk factors in both younger and older subjects, but proportions of subjects in each individual waist group were higher in older than in younger groups for systolic blood pressure, diastolic blood pressure, fasting glucose, and 2-hour glucose in men, and for systolic blood pressure, fasting glucose, 2-hour glucose, total and LDL-cholesterol, and triglyceride in women. CONCLUSIONS: Our data indicate that the waist circumference cutpoints proposed by NHLBI and WHO standards are useful for the prediction of cardiovascular disease risk factors in older as well as in younger men and women.

Adolescent↗
PubMed1996

Effect of C-peptide administration on whole body glucose utilization in STZ-induced diabetic rats.

Recent studies suggest that C-peptide stimulates glucose transport in isolated skeletal muscle. In order to determine the effect of C-peptide on whole body glucose utilization, streptozotocin (60 mg kg-1) (STZ)-induced diabetic and normal rats were studied using the euglycaemic clamp procedure and continuous infusion of somatostatin (1.0 micrograms kg-1 min-1) in pentobarbital-anaesthetized rats. Plasma insulin levels during the 6.0- and 30.0-mU kg-1 min-1 insulin infusions rose to 70-90 microU mL-1 and 500-700 microU mL-1, respectively. Blood glucose concentrations were clamped at 7.5-7.9 mmol L-1 in the diabetic rats and at basal levels or 7.7 mmol L-1 in the non-diabetic (normal) rats. Biosynthetic human C-peptide (0.5 nmol kg-1 min-1) was infused in 12 diabetic and 11 normal rats, resulting in concentrations of 26-41 nmol L-1. The metabolic clearance rate of glucose (MCR) for the diabetic rats receiving C-peptide (12.0 +/- 1.0 mL kg-1 min-1) was significantly (P < 0.01) higher than that in the diabetic rats given saline (6.3 +/- 0.7 mL kg-1 min-1) or a randomly scrambled C-peptide (7.8 +/- 1.3 mL kg-1 min-1) at low-dose insulin infusion but not at the high-dose insulin infusion. In normal rats C-peptide did not significantly increase the MCR for glucose. These results thus demonstrate that C-peptide has the capacity to increase glucose utilization in STZ-induced diabetic rats.

Animals↗
PubMed1996

Effects of meal frequency on body composition during weight control in boxers.

The effects of meal frequency on changes in body composition by food restriction were investigated. Twelve boxers were divided between a two meals day-1 group (the 2M group) and a six meals day-1 group (the 6M group). Both groups ingested 5.02 MJ (1200 kcal) day-1 for 2 weeks. Although there was no difference in change of body weight by food restriction between the two groups, the decrease in lean body mass (LBM) was significantly greater in the 2M group than in the 6M group. The decrease in urinary 3-methylhistidine/creatinine was significantly greater in the 6M group than in the 2M group. These results suggest that the lower frequency of meal intake leads to a greater myoprotein catabolism even if the same diet is consumed.

Adult↗
PubMed1986

[Analyses of industrial society from ecology--modeling analyses of industrial ecological system].

A macroscopic industrial ecological model has been developed to investigate the effects of changes in industrial structure on social well-being in general and health in particular. The model is composed of the following sectors: industry and employment, environment and pollution, and population and health care. The model was calibrated using available data of the past 60 years for Japan. The simulation study was conducted with the time span of 1920 to 2000. The results indicated that the gradual shift, in the industrial structure of Japan, would improve the level of living standards resulting in enhanced health service capability and lower death rate although increasing adult disease rates in the aged society. Also the rapid future growths of service industry and information and communication were observed.

Ecology↗
PubMed1986

[Gastric and duodenal ulcers as occupational psychosomatic diseases].

Various stresses are considered to be involved in the development of gastric and duodenal ulcers. We interviewed patients of either gastric ulcer group (GU) or duodenal ulcer group (DU) with regular occupation who were admitted to our Psychosomatic Illness Department in order to examine the differences in the characteristics of their stress and developmental factors of their diseases between the two groups. Developmental factors were scored for comparison. The following results were obtained. Though group DU was generally younger than group GU, it tended to have a greater number of episodes. No significant difference was found between the two groups in living habits, life history, or familial, social and physical environments. However, group DU had greater stress than group GU in the working environment. A significantly greater number of patients in group DU smoked and had problems in personal relations as compared with GU. There was a significant correlation between smoking habit and stressfulness of the working environment in both groups. In group DU, there was a significant correlation between the father-child relationship and personal relations. In group DU, a significant number of those who had problems in the relation with their superiors at work had problems in the father-child relation. These findings show that patients with duodenal ulcer had more problems in the working environment, particularly in personal relations, than those with gastric ulcer, and smoking habit appears to accelerate the development of the diseases. Also, a possible association was suggested between problems of personal relations at work and the history of growth.

Adult↗
PubMed1985

Follow-up study on pulmonary function of dust workers: an epidemiological evaluation of discontinued workers of dust operations.

An epidemiologic study on 176 dust workers from various facilities was initiated in 1978. Their mean age was 48.3 years and mean duration of employment was 21.6 years. No workers complained of chronic cough and phlegm. Their chest X-rays were found to belong to Category I of the diagnostic criteria for pneumoconiosis in Japan. Pulmonary function test was performed on these workers, however, 54 workers discontinued taking part in the study by the end of 1979, and 49 workers had discontinued by 1981. A total of 73 workers had a five-year follow-up survey of pulmonary function. Forced expiratory volume in one second divided by forced vital capacity (FEV1.0/FVC) and forced expiratory flow rate at 25% of FVC divided by height (V25/H) were mainly compared by smoking habit, work years, type of job, size of company, and the time when they discontinued their jobs. Predicted percentage values of lung function were used for the adjustment of the influence of workers' ages. Decrement of FEV1.0/FVC and V25/H in the five-year follow-up group were larger than the screening level. The mean values of those functional parameters in the early discontinued group were lower than late discontinued and active working groups. The active working group was considered to be a physically healthy workers' population.

Adult↗
PubMed1983

[A follow-up study on pulmonary functions of workers exposed to various forms of dust. Observation on the workers of pneumoconiosis in Kitakyushu].

Serial spirograms of 121 dust workers whose chest X-rays were found to be "class 1" of the diagnostic criteria for pneumoconiosis were obtained during 1978-80. Yearly changes of pulmonary function variables (%VC, FEV1, FEV1/FVC%,V25/H, and V50/V25) by age, smoking habit, total years of exposure to dust, and work history were evaluated. The average age of the dust workers was 48.0 +/- 5.5 years, and the average years of exposure to dust was 21.6 +/- 6.8 years in 1978. Eighty-two dust workers smoked with the mean smoking history of 24.7 pack-years. No significant differences of spirograms were found between the smoking and non-smoking groups. Among the smokers, however, linear regression of FEV1/FVC% by age gradually decreased during 1978-80. All the pulmonary function variables showed no correlation with smoking history as well as total years of dust exposure. All the dust workers were classified into eight types of work by their histories; crushing and quarrying operators, brick mason, foundry and grinding operators, asbestos workers, underground miners, refractory material workers, pyrites roasters, and welders. The underground miners showed lower FEV1/FVC% and V25 than the average. However, the difference of such pulmonary function variables by eight types of work was not significant by analysis of variance. Since aging is the most dominant factor for pulmonary dysfunction, a longer observation on this group will be needed.

Age Factors↗
PubMed1983

[Field tests of a new passive personal monitor for organic vapors].

The method making use of a New Du Pont PRO-TEKTM G-AA Organic Vapor Air Monitoring Badge, was applied to evaluate the concentration of organic vapor in a working atmosphere. Other methods such as the direct air sampling method and the method of adsorption on charcoal tube were compared with the above mentioned method. In the comparative study of these methods in working places, similar results were obtained by the new badge method and the charcoal tube method, though different results were obtained between the direct air sampling method and the mentioned two methods. The differences may have resulted from the period needed for the sampling, that is, an intermittent sampling was generally used for the direct sampling method. In a study of personal exposure monitoring by the badge method and the tube method, the results obtained by the badge method were lower than those obtained by the latter method suggesting the effects of the response of the badge on organic vapor in working places. The relationships between the instantaneous changes of the concentration of organic vapor in the atmosphere and the response time of the badge will be discussed elsewhere.

Air Pollutants↗