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Biomedical subjects

H Shimokata

Publications and source records attributed to H Shimokata.

At least 55 records · Page 3Linked to original sources
PubMed1997

Analysis of cancer mortality among atomic bomb survivors registered at Hiroshima University.

The aim of this study was to investigate the late effect on cancer mortality risk of the radiation exposure of atomic bomb survivors who comprised a study population different from that previously studied by the Radiation Effects Research Foundation (RERF). We examined survivors residing in Hiroshima Prefecture, who were followed up between 1968 and 1989 by the Research Institute for Radiation Biology and Medicine (RIRBM) at Hiroshima University. We used the dose-evaluation system known as Atomic Bomb Survivors 1993 Dose (ABS93D), which was based on the Dosimetry System 1986 for the survivors registered with RERF. The dose estimation was applied in a total of 35,123 subjects. Among survivors who had been alive for > 20 years after the bombing, the relative mortality risk of leukaemia at 1 Gy of organ dose was 2.37 (90% confidence interval: 1.36-3.39), which was significantly higher than the zero dose control group. Similarly, significantly higher risks were observed for all cancers except leukaemia, including cancers of the lung, colon and female breast. Comparison is made with RERF results regarding temporal changes in the relative risk. Although we observed slightly lower relative risks than RERF values for the cancer of the stomach and lung, and for all cancer except leukaemia, no marked trends for any cancer were observed in this study. Though there were some differences in population between RERF and RIRBM, no marked discrepancies were observed.

Adolescent↗
PubMed1996

[Assessment of biological age and indices of aging].

People age at different rates. Accurate assessment of aging is indispensable for research in gerontology and geriatrics. Biological age can be estimated from age-related changes in physiological and physical functions. Disease, physical activity, and life-style have been shown to affect aging. Biological age was estimated by multiple regression. We studied how external appearances, diet, job status, smoking and alcohol consumption were related to aging. The subjects were 2,385 people of both sexes whose ranged from 15 to 87 years. Aging estimated by external appearance strongly correlated with changes in physiological functions and in physical strength. Diet was also found to be significantly related to aging. Biological age was significantly lower than calendar age in subjects with managerial jobs in non-smokers, and in those who drank a moderate amount of alcohol. These results show that biological age can be useful in aging research.

Adolescent↗
PubMed1995

Two-point discrimination test of the skin as an index of sensory aging.

Although the two-point discrimination test of the skin is a simple test of the sensory nerve function, there have been few studies on age-related changes in the ability to discriminate between two points in a large noninstitutionalized population. In this study we attempted (1) to determine normal values on the two-point discrimination test by age and gender in a large population with a wide age span; (2) to describe age-related changes on the two-point discrimination test; and (3) to test the independence of this index from other indices measuring physiological aging by sensory functions, such as accommodation and hearing tests. The subjects were 2,036 men and women aged 10-87 years. The minimal distance at which two points could be discriminated was measured longitudinally on a line from the palmar pad to the base of the index finger of the right hand. The two points of a caliper were applied at the same time (stationary two-point discrimination test) using the weight of the caliper alone. An age-related decline in the ability to discriminate two points was apparent, but there were no significant differences in ability between men and women. The minimal distance of discrimination on the hand increased almost linearly between 10 and 60 years of age. The results of the two-point discrimination test of the skin were independent of those of visual accommodation tests and hearing loss of high-frequency sound. From these results, the two-point discrimination test of the skin can be used as a powerful and simple index of sensory aging.

Adolescent↗
PubMed1995

Survival analyses of atomic bomb survivors in Hiroshima Prefecture, Japan, 1968-1982--cancer mortality risk among early entrants.

We examined the mortality risk due to all causes of death and due to malignant neoplasms during 1968-82 among 204,209 atomic bomb survivors, including 49,215 early entrants. We used data compiled by the Research Institute for Radiation Biology and Medicine at Hiroshima University, which conducts mortality surveillance of these survivors in Hiroshima Prefecture, Japan. The purposes of this study were to investigate whether there was any relationship between exposure status and mortality risk among survivors, not altered by adjustment for confounding factors, and whether there were any differences among early entrants to the region within 2 km of the hypocenter after the bombing in mortality risk associated with date of entry and duration of stay. The mortality risk in directly exposed survivors decreased with distance from the hypocenter, even after adjustment for confounding factors. Entrants who entered the region on the day of the bombing had a significantly higher risk of mortality due to malignant neoplasm than those who entered thereafter, even after adjustment for the length of stay. The same results were obtained throughout the study period.

Adult↗
PubMed1994

[The actual conditions of patients with intractable diseases in Hiroshima Prefecture].

All 3,515 patients of intractable diseases who received medical benefits in Hiroshima prefecture were surveyed to determine actual conditions of daily life while being treated. This is the first study in Japan, which has looked at daily life of all patients of intractable diseases at the level of a whole prefecture. Effective collection rate of the questionnaire was 78.8% (2,768 cases). The results are summarized as follows: 1) Many patients and their families wish to be treated at home, with the more severely impaired patients expressing a greater need for home care. 2) Large regional differences were seen in required travel time to visit the hospital, and in the percentage of patients and their families who expressed a desire for medical specialists in intractable diseases for their region. 3) While income of families of the severely impaired patient was generally low, their medical payment burden was heavy. In addition families of patients were heavily burdened physically and mentally. The tasks that lie ahead in the care of patients of intractable diseases would be home care assistance, correction of regional differences, and financial aid for severely impaired patients.

Activities of Daily Living↗
PubMed1993

[Aging, basal metabolic rate, and nutrition].

Age is one of the most important factor of changes in energy metabolism. The basal metabolic rate decreases almost linearly with age. Skeletal musculature is a fundamental organ that consumes the largest part of energy in the normal human body. The total volume of skeletal muscle can be estimated by 24-hours creatinine excretion. The volume of skeletal musculature decreases and the percentage of fat tissue increases with age. It is shown that the decrease in muscle mass relative to total body may be wholly responsible for the age-related decreases in basal metabolic rate. Energy consumption by physical activity also decreases with atrophic changes of skeletal muscle. Thus, energy requirement in the elderly decreases. With decrease of energy intake, intake of essential nutrients also decreases. If energy intake, on the other hand, exceeds individual energy needs, fat accumulates in the body. Body fat tends to accumulate in the abdomen in the elderly. Fat tissue in the abdominal cavity is connected directly with the liver through portal vein. Accumulation of abdominal fat causes disturbance in glucose and lipid metabolism. It is shown that glucose tolerance decreases with age. Although age contributes independently to the deterioration in glucose tolerance, the decrease in glucose tolerance may be partly prevented through changes of life-style variables, energy metabolism is essential for the physiological functions. It may also be possible to delay the aging process of various physiological functions by change of dietary habits, stopping smoking, and physical activity.

Adipose Tissue↗
PubMed1991

Age as independent determinant of glucose tolerance.

It has been proposed that the decline in glucose tolerance with age is not a primary aging effect but is secondary to a combination of other age-associated characteristics, i.e., disease, medication, obesity, central and upper-body fat deposition, and inactivity. To test this hypothesis, we first eliminated from analysis the Baltimore Longitudinal Study of Aging participants with identifiable diseases or medications known to influence glucose tolerance. Seven hundred forty-three men and women, aged 17-92 yr, remained for analysis. As indices of fatness, body mass index and percent body fat were determined. As indices of body fat distribution, waist-hip ratio and subscapular triceps skin-fold ratio were calculated. As indices of fitness, physical activity level, determined by detailed questionnaire, and maximum 02 consumption were calculated. We tested whether the effect of age on glucose tolerance remains when data were adjusted for fatness, fitness, and fat distribution; 2-h glucose values were 6.61, 6.78, and 7.83 mM for young (17-39 yr), middle-aged (40-59 yr), and old (60-92 yr) men and 6.22, 6.22, and 7.28 mM for the three groups of women, respectively. The differences between the young and middle-aged groups were not significant, but the old groups had significantly higher values than young or middle-aged groups. Fatness, fitness, and fat distribution can account for the decline in glucose tolerance from the young adult to the middle-aged years. However, age remains a significant determinant of the further decline in glucose tolerance of healthy old subjects.

Adipose Tissue↗
PubMed1990

Body weight variability in men: metabolic rate, health and longevity.

The health implications of body weight fluctuation were examined using data from 846 men with a mean age of 56.4 years, enrolled in the Baltimore Longitudinal Study of Aging. Body weight fluctuation was studied in relation to three general categories of health-related outcome: (i) basal metabolic rate, (ii) risk factors for coronary heart disease (CHD), and (iii) rates of CHD, cancer mortality, and all-cause mortality. Weight fluctuation was defined as intraindividual variability in body weight about a time-dependent regression slope. Outcomes (i) and (ii) were described in terms of a subject's rate of change during the same time period. All analyses were adjusted for three covariates: age, level of obesity and linear trend in body weight over time. (i) Body weight variability is positively associated with changes in metabolic rate expressed either per surface area or per lean body mass (i.e. less decrease over time among the most weight-variable men). (ii) Body weight variability is associated with greater decreases in glucose tolerance and with greater increases in the ratio of subscapular to triceps skinfolds, but not with changes in systolic blood pressure, waist-hip ratio, serum cholesterol or triglyceride levels. (iii) Body weight variability is not predictive of subsequent CHD, cancer, or all-cause mortality. These results do not confirm previous findings regarding weight fluctuation and 'hard' endpoints but do raise the possibility that weight cycling might modify eventual cardiovascular risk via adipose redistribution or glucose tolerance impairment.

Adipose Tissue↗
PubMed1990

[Biological age and longitudinal study of aging].

We assessed the biological aging status by multiple regression analysis of clinical parameters. Estimated ages of external appearance, physiological function, physical strength and general biological status were calculated. The aging grade was defined as the percent estimated age to chronological age. The aging grade was lower in the managers, and in nonsmokers. It was lower in subjects who drank a small amount of alcohol than in those who drank a large amount of alcohol or those who did not drink alcohol. We also studied the longitudinal changes of 27 clinical parameters. Physical, hematological and blood biochemical data were annually recorded for a 10-year period. Age-time matrix was made for each parameter and was analyzed in terms of aging, cohort and time, by utilizing [1] longitudinal, [2] cross-sectional and [3] time series approaches. The parameters that were considered to be affected by aging were right grip strength (reduced), and sedimentation rate (increased).

Adolescent↗
PubMed1989

Studies in the distribution of body fat. III. Effects of cigarette smoking.

Cross-sectional associations between smoking habits, body mass index, and waist-hip ratio (WHR) were examined in 1122 men aged 19 to 102 years. Weight and body mass index were significantly lower in cigarette smokers than in nonsmokers when age was taken into account. The WHR in smokers was significantly higher than in nonsmokers. A graded dose-response relationship was found between the number of cigarettes smoked and the WHR. Longitudinal associations between changes in smoking habits and changes in the WHR were examined during follow-up visits. In the period between these pairs of visits, weight increased when subjects quit smoking and decreased when they started smoking, as expected. The increase in WHR among those who quit smoking was, however, significantly less than the expected increase if smoking had continued. The WHR in those who started smoking actually increased despite their loss of weight. These paradoxical changes in WHR indicate that there are harmful effects of cigarette smoking on the pattern of distribution of body fat. These facts introduce still another reason to suggest that the decision to initiate or to continue smoking to control body weight is unwise.

Adult↗
PubMed1989

Studies in the distribution of body fat: I. Effects of age, sex, and obesity.

The pattern of body fat distribution has been shown to be related to a large number of variables of clinical importance. A variety of indices have been devised, many of them simple enough to be useful in large-scale clinical studies. Relationships among these several indices and systematic information on the effects of age, sex, and obesity have, however, not been systematically studied. Five anthropometric ratios that classify individuals into different body types have been computed for 1179 men and women aged 17-96 years. These are: waist hip ratio, arm thigh ratio, waist thigh ratio, waist arm ratio, and subscapular triceps skinfold ratio. In general, the age patterns show progressive trends toward increasing upper and central body fat deposition with age. In women there tends to be a postmenopausal acceleration of this trend. The ratios are distinctly higher in men than in women and are also independently influenced by the body mass index. Predictive equations that take age and BMI into account for each of the indices for men and women have been provided.

Adipose Tissue↗
PubMed1989

Studies in the distribution of body fat. II. Longitudinal effects of change in weight.

Information on the effects of age, sex, obesity and weight change on the fat distribution pattern has not been systematically reported. As an index of body fat distribution, the waist hip circumference ratio (WHR) was computed in 370 men and 177 women aged 22-86 years, participants of the Baltimore Longitudinal Study of Aging. For cross-sectional analysis, initial data on the participants were analyzed; for longitudinal study, the changes in the measurements related to weight change during a 5-year follow-up were analyzed. From cross-sectional analysis: (1) waist circumference is larger in men than in women and increases progressively with age; (2) hip circumference shows no consistent age or sex differences; (3) thus, the well known sex differences in WHR are totally attributable to differences in waist circumference; (4) increases in WHR with age occur in both men and women. From longitudinal analysis of weight change: (1) changes in waist and hip circumferences are correlated directly with changes in weight in both sexes, but there are large differential sex effects; (2) in men, waist changes dominate; (3) in women, waist and hip changes are nearly the same; (4) thus, weight changes in men have large effects on the WHR, while in women changes in WHR are very small. Men, as a group, have a more dangerous fat distribution pattern than women, but men as a group will show a more beneficial pattern of change in WHR with weight control than women.

Adipose Tissue↗
PubMed1986

The digital plethysmogram as an index of ageing grade.

In order to determine whether the digital plethysmogram (PTG) can be used as an index of ageing or not, the PTG was recorded in 89 males and 110 females in a pilot study. Of the parameters which were calculated from the PTG, up-stroke time corrected by pulse rate (SXp time) showed the strongest correlation with age. The PTG was recorded in 1066 males and 761 females. There was a significant correlation between age and SXp time in both sexes. The change of SXp time with age in the younger age group was more rapid than in the old age group. From these results, SXp time of the PTG can be used as an index of ageing, especially in the young to middle-aged group.

Adolescent↗
PubMed1985

A new unstable, high oxygen affinity hemoglobin: Hb Nagoya or beta 97 (FG4) His----Pro.

An unstable hemoglobin was detected by isopropanol and heat precipitation tests in a 49-year-old Japanese man suffering from acute exacerbation of a chronic hemolytic disorder which was apparently triggered by infection of cholelithiasis. One of his two sons carried the same abnormal hemoglobin, and was jaundiced, but otherwise healthy, without anemia. The abnormal hemoglobin focused at a slightly more anodic position than Hb A in thin layer polyacrylamide gel electrofocusing. The abnormal beta chain emerged after normal beta chain in reverse phase high performance liquid chromatography of the hemolysate. It comprised 16.7% and 25.5% of the total beta chain in the propositus and his son, respectively. The partially heme-depleted abnormal beta subunit was precipitated with p-chloromercuribenzoic acid, and the abnormal beta chain was isolated by urea CM-cellulose column chromatography. Structural analysis demonstrated substitution of proline for histidine at position 97 (FG4) in the beta chain. The abnormal hemoglobin was purified by ion-exchange column chromatography. It showed a hyperbolic oxygen equilibrium curve indicating a high oxygen affinity and the absence of cooperative intersubunit interaction. Subunit dissociation seemed to be slightly enhanced. The variant was markedly susceptible to oxidation and rapidly lost heme upon oxidation.

Amino Acid Sequence↗