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Biomedical subjects

Y Kusaka

Publications and source records attributed to Y Kusaka.

At least 73 records · Page 4Linked to original sources
PubMed1996

Diffusion of water in rat sciatic nerve measured by 1H pulsed field gradient NMR: compartmentation and anisotropy.

Diffusion of water was measured in rat sciatic nerve at 22.5 +/- 0.5 degrees C using the spinecho pulsed-field gradient sequence. Three effective diffusion coefficients (ca. 1.1, 0.23, and 0.02 x 10(-9) m2/s) were obtained at a diffusion time of 10 ms in fresh nerve and they showed minimal orientation dependency. The extracellular water signal was quenched by 10 mM MnCl2, and 10% of the water signal remained. Two diffusion coefficients of water were now observed at a diffusion time of 10 ms. The faster coefficient (65% of the remaining signal) was 0.8 x 10(9) m2/s when the axis of the nerve fiber was set parallel to the gradient (D0), and was 0.3 x 10(9) m2/s when the axis of the nerve fiber was set perpendicular to the gradient (D90). The values of D90 and D0 decreased when the diffusion time was increased from 3 ms to 50 ms. A cylinder diameter of 5.4 microns was obtained on the assumption of restricted diffusion in a cylindrical geometry. This agrees with the average inner diameter of axons in the rat sciatic nerve. The slower diffusion component (0.02 x 10(-9) m2/s, 35% of the remaining signal) did not show orientation or diffusion time dependency, and may be attributed to the intracellular water of the Schwann cell body.

Animals↗
PubMed1996

Dynamic changes of constituents in bronchoalveolar lavage fluid in experimental silicotic rats.

Bronchoalveolar lavage (BAL) is a useful and safe method for sampling cellular and biochemical components from the lung. Analysis of bronchoaveolar lavage fluid (BALF) constituents is useful for defining the stage of disease, and for assessing disease progression and the response to therapy in lung disorders. We studied the dynamic changes in various indices for BALF and the accompanying silicotic changes in the lungs of rats at different times after quartz instillation. Total cell counts, LDH activity, protein concentration, and lipoperoxide (LPO) in the BALF of experimental silicotic rats were significantly higher than those of control rats (P < 0.05 or 0.01). After instillation, quartz content, total cell counts, LDH activity and protein concentration in BALF tended to decrease over time. These findings suggested that in acute silicosis, quartz can induce serious inflammation and damage the lung, with acute lung proteinosis seen as the main change in this stage.

Animals↗
PubMed1996

[An epidemiological study of malformations in infants delivered from diabetic mothers].

The purpose of this study is to investigate the risks of delivery of malformed infants in diabetic mothers in comparison with those in non-diabetic mothers and to clarify risk factors for malformation due to maternal diabetes. The delivery records available at the Department of Obstetrics and Gynecology, Mie University School of Medicine between 1979 and 1992 showed 103 mothers with diabetes mellitus among 4,353 pregnancies. The incidence of malformation in infants born to diabetic mothers was 9.7%, and it was 2.5% overall. By logistic regression analysis of all mothers in this series, diabetes as well as maternal age, and fetal age were shown to be significant risk factors for malformation. A further logistic model for diabetic mothers revealed that a younger age of the mother at the time of labour, low fetal age, older age at onset of diabetes, previous history of pregnancies, and an Hemoglobin A1 (HbA1) level higher than 9% were independent risk factors, among which HbA1 (>9%) showed the highest odds ratio of 24. Careful management is therefore needed to reduce the risk of malformation in pregnancy of diabetic mothers.

Adult↗
PubMed1996

[Relationship of hypertension prevalence in companies to business type and scale--from an analysis of health examination results in Fukui prefecture].

The results of health examinations of 89,299 examines from companies in Fukui Prefecture conducted pursuant to the Occupational Safety and Health Act were analyzed to study the relationship between the prevalence in these companies of hypertension, and company size business type. The Mantel-Haenszel method was utilized to adjust for age structure of the examinees according to gender and the type of business of their companies to compare prevalence of hypertension. The results of the analysis indicated that the prevalence of hypertension was significantly higher in small-scale companies for the female examinees working in pulp/paper processing and motor freight transport business than in large-scale companies, but no significant difference was seen for scale of business when the female examinees were grouped without regard to the business type of their companies. In the case of the male examinees, the analysis results revealed that the prevalence of hypertension was significantly higher in small-scale companies for those working in ceramic/earth/rock, motor passenger transport and hotel/restaurant business than in large-scale industry while the prevalence of hypertension was significantly higher in large-scale companies for those working in non-ferrous metal industry, financial and other types of business. Moreover, the analysis results for the male examinees grouped without regard to the type of business of their companies indicated that the prevalence of hypertension remained significantly higher in small-scale companies. The above also suggests the need for measures for health care of workers that considers business type and scale for the purpose of primary prevention of hypertension.

Adult↗
PubMed1995

Direct effect of cadmium on citrate uptake by isolated rat renal brush border membrane vesicles.

High incidence of multiple kidney stone formation has been observed among workers exposed to cadmium (Cd). Citrate is known to be a protective factor against renal stone formation. To study the direct effect of cadmium on citrate uptake by the renal brush border membrane, we exposed isolated rat renal brush border membrane vesicles (BBMV) to cadmium and determined their citrate uptake characteristics. BBMV were prepared by the divalent cation precipitation method. Citrate uptake was measured by the Millipore rapid membrane filtration technique. Preincubation of BBMV with 2 and 10 mM CdCl2 for 1 min significantly inhibited citrate uptake compared with that of BBMV without Cd. Analysis of the time course of citrate uptake during 30-min preincubation of BBMV with 0.5 mM Cd also revealed significant reduction of the uptake compared with that of the control BBMV without preincubation. These findings indicate that preincubation of BBMV with cadmium results in time-dependent and concentration-dependent inhibition of citrate uptake.

Animals↗
PubMed1995

Effect of sulfo-N-succinimidyl palmitate on the rat heart: myocardial long-chain fatty acid uptake and cardiac hypertrophy.

Abnormal long-chain fatty acid metabolism has been suggested as having a role in the genesis of certain cardiac diseases, and depressed myocardial long-chain fatty acid uptake has been clinically demonstrated in some patients with hypertrophic cardiomyopathy. However, the site where long-chain fatty acid metabolism is affected in cardiomyopathy remains unclear. Although cardiac hypertrophy is reported to be induced in rats by a fat-free diet, little is known of the consequences of depressed myocardial long-chain fatty acid uptake. Sulfo-N-succinimidyl derivatives of long-chain fatty acids have been shown to irreversibly inhibit long-chain fatty acid transport. To investigate the possible linkage of abnormal long-chain fatty acid uptake with cardiac hypertrophy, myocardial long-chain fatty acid uptake was blocked in rats using a sulfo-N-succinimidyl derivative of palmitate (SSP). SSP was intraperitoneally administered to rats for 12 weeks, and its effects on physiological parameters, and cardiac morphology were studied, SSP treatment (20 mg/kg) caused a 12% increase in heart weight (663.7 +/- 33.6 mg in controls v 741.2 +/- 26.5 mg after SSP treatment) and an 11% increase in the heart weight to body weight ratio (2.46 +/- 0.10 in controls v 2.72 +/- 0.17 after SSP) without any significant change of body weight. No significant differences were observed in blood pressure, heart rate, and serum hormones (insulin and triiodothyronine) between the control and SSP-treated groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1995

[Bone mineral density of the lumbar spine and its relation to biological and lifestyle factors in middle-aged and aged Japanese women (Part 3). Relationships of physical fitness and lifestyle factors to bone mineral density in premenopausal and postmenopausal women].

We recruited community-dwelling women for participation in a study to investigate the effects of risk factors in lifestyle on bone mineral density (BMD). The subjects were 177 women aged 35 years and over living in a rural area in Fukui Prefecture. Their BMD of the lumbar spine (L2-L4) was determined by dual energy X-ray absorptiometry (DXA). In addition to measurements of height, body weight and grip strength, the lifestyles of the women, including physical load in work, sporting activities, smoking habits, calcium intake, and history of bone fracture were interviewed in detail. Adjusted for age, the BMD significantly correlated to body weight (r = 0.337, p < 0.05 for premenopausal women and r = 0.289, p < 0.01 for postmenopausal women) and body mass index (kg/m2) (r = 0.291, p < 0.05 for premenopausal women and r = 0.190, p < 0.05 for postmenopausal women). These results indicated the lower body weight to be a risk factor for the osteoporotic process in middle-aged and aged women. With respect to the grip strength as a physical fitness indicator, a significant correlation coefficient (r = 0.267, p < 0.01) with BMD was obtained for postmenopausal women independent of age and body weight. In univariate analysis, BMD showed no significant correlations with sporting activities, smoking habits, lower back pain and history of bone fracture for either premenopausal women or postmenopausal women.(ABSTRACT TRUNCATED AT 250 WORDS)

Asian People↗
PubMed1995

[Changes in physique and obesity of school children in an elementary school observed from the Meiji era to the Showa era].

Data on height and weight were collected at an elementary school in Fukui Prefecture from 1889 through 1934 (observation period). During the observation period, the school area, consisting of a mountainous region and a plain region, was not changed. Using these data, analysis showed that there were: (1) differences in physique between children from the mountainous region and those from the plain region, which was suggested by the school teachers during the observation period, (2) chronological changes in physique, (3) chronological changes in the features of the height velocity curve in the analysis when school children at the same school born in the 1980s were used as a control, (4) chronological changes in the balance of weight to height and (5) changes in the prevalence of obesity. The results were as follows: (1) during the observation period, the physiques of children in the mountainous region were consistently inferior to those in the plain region, (2) during the period, the average physique of the school children aged 12 was consistently inferior to the overall average for Japanese pupils of the same age, (3) during the observation period, the onset of the adolescent growth spurt was later by one year compared with that of current controls, (4) the ratio of weight to height stratified by 3cm intervals during the observation period was almost the same as that in current controls, (5) during the observation period, the prevalence of obesity in boys (6%) was lower than that in current controls (10%). However, the obesity prevalence in girls during the period was higher than that in the controls. However, this findings might be associated with wearing kimono during measurement. By contrast, these differences have recently disappeared. These results suggest that there were consistent differences in physique that persisted between regions in the school area and in Japan as a whole across several eras.

Body Constitution↗
PubMed1995

[Computed tomography of pneumoconiosis].

This review describes the usefulness of computed tomography (CT) and high-resolution computed tomography (HRCT) in image evaluation in pneumoconiosis. For pneumoconiosis, in the same way as for other diffuse lung diseases, conventional CT includes 10 mm collimation scans at 1 cm intervals from the apex to the base of the lung, whereas HRCT uses five to six 1.2 to 3 mm collimation scans at predetermined representative locations including the aortic arch, the tracheal carina, and 2 cm above the dome of the right hemidiaphragm. The CT scans are performed in the supine position in silicosis and coal workers' pneumoconiosis, and both in the supine and prone position in asbestosis. In silicosis, CT is superior to chest radiography in detecting coalescence of nodules and early stage formation of large opacities. There are good correlations between HRCT findings and histological changes, especially in secondary pulmonary lobules. With HRCT, small nodules are found to be located in the center of the secondary pulmonary lobule in silicotic lungs. The mild emphysematous change associated with silicosis can also be found with HRCT. In coal workers' pneumoconiosis, the HRCT is useful in detecting nodules located in the subpleural and fissural subpleural areas. In asbestosis, the conventional CT can detect pleural plaques more sensitively than chest radiography. HRCT is also especially useful in detecting earlier fibrotic change in asbestosis in lung parenchyma, apparent as subpleural lines, parenchymal bands, subpleural curvilinear line shadows and so on.(ABSTRACT TRUNCATED AT 250 WORDS)

Asbestosis↗
PubMed1995

[A cross-sectional analysis on relationships between maximum oxygen uptake and risk factors for cardiovascular diseases].

We examined the relationships between maximum oxygen uptake (Vo2max) and cardiovascular risk factors including age (year), systolic blood pressure (mmHg), diastolic blood pressure (mmHg), serum total cholesterol level (mg/dl), serum high-density lipoprotein level (mg/dl), serum triglyceride level (mg/dl), blood glucose level (mg/dl), serum uric acid level (mg/dl), body fat (%bw), Body Mass Index (BMI), alcohol (points/day), cigarettes (/day), and physical activity (METs.exercise time/30 days). The alcohol point was defined as follows: beer 633ml = a glass of whiskey and water - sake 180ml = 1 point, and totaled at 30 days. The subjects of our study were 162 males (aged 40.6 +/- 13.1) and 133 females (aged 41.3 +/- 11.1) who underwent medical and physical examinations at the Fukui Industrial Health Center from April, 1991 to June, 1992. As a result of simple correlation analysis in males, Vo2max had significantly negative correlations with age (r = -0.223, p < 0.01), systolic blood pressure (r = -0.228, p < 0.01), diastolic blood pressure (r = -0.239, p < 0.01), or serum triglyceride level (r = -0.258, p < 0.001), serum uric acid level (p < 0.05), body fat (r = -0.230, p < 0.01), and BMI (r = -0.312, p < 0.001), and was positively correlated with physical activity (r = -0.249, p < 0.01). On the other hand, in females, age (r = -0.224, p < 0.01), systolic blood pressure (r = -0.222, p < 0.01), diastolic blood pressure (r = -0.267, p < 0.01), serum triglyceride level (r = -0.261, p < 0.001), body fat (r = -0.280, p < 0.01), and BMI (r = -302, p < 0.001), had significantly negative correlations with VO2max. However, partial correlations were tested after controlling body fat, BMI, cigarette, alcohol, physical activity, and age, none of the factors correlated with VO2max significantly. These findings suggest that the risk factors for cardiovascular diseases are related to VO2max, and the life style has an influence on these correlations. Thus, VO2max may be a comprehensive indicator for health promotion among the working population. Furthermore a longitudinal study is required to determine whether the increase in VO2max is related to the improvement in the risk of cardiovascular diseases.

Adult↗
PubMed1995

[An epidemiological study of factors relating to mercury sensitization].

We investigated factors relating to mercury sensitization in 156 medical students (mean age 22.7 +/- 2.4, mean +/- S.D., male 113, female 43). Their allergic symptoms, lifestyles and family histories were studied by questionnaire. Patch tests were performed on them with HgCl2 (0.05%aq.), NiSO4 (5%aq.), PPD (2%pet.) and urushiol (0.01%pet.). Anti-dermatophagoides and anti-cryptomeria pollen IgE antibodies in serum were also measured. While the positive rates of urushiol, nickel and PPD were 11.1%, 5.1% and 2.6%, respectively, that of mercury was as high as 12.8%. Each allergen specific antibody positivity and past histories of allergic diseases were not associated with mercury sensitization (by the chi-square test). Mercury sensitized students had significantly more frequently experienced eczema caused by cosmetics, shampoos, soaps and haircreams (by the chi-square test, p < 0.005). They also had significantly more teeth treated with metals compared to the controls (one-tailed t-test, p < 0.05). And their urinary mercury concentrations were significantly higher than those of the controls (one-tailed t-test, p < 0.05). These findings suggest that mercury sensitization is associated with exposure to mercury in the living environment.

Adult↗
PubMed1994

[Bone mineral density of the lumbar spine and its relation to biological and lifestyle factors in middle-aged and aged Japanese women (Part 1). Relationship of age and menopause to bone mineral density of the lumbar spine measured by dual-energy X-ray absorptiometry].

Bone mineral density (BMD) of the lumbar spine in 198 community-dwelling Japanese women aged 35 years and over was measured by dual-energy X-ray absorptiometry to investigate the effects of aging and menopause on BMD. A highly significant negative correlation between age and BMD was observed in postmenopausal women as widely accepted. We found a weak but statistically significant negative correlation between age and BMD in even premenopausal women, suggesting that their bone loss had commenced before menopause. Marked decrement in BMD was seen during the first ten years after menopause. Menopause clearly accelerated bone loss in the lumbar spine. Two-way analysis of variance of BMD on age and menopausal status showed that these explanatory variables had a significantly decreasing effect on BMD independently of each other. Menopausal status had a greater sum of squares than age, which suggested that menopause played a greater role in bone loss than did aging. Early menopause has been implied as one of the risk factors for bone loss. The women aged 50 to 59 having encountered menopause before 49 years old exhibited significantly lower BMD than those of similar age who experienced menopause at age 49 and older. This difference in BMD was not observed in the women aged 60 and over. Early menopause was no more likely to be a risk factor for bone loss in the elderly women. We conclude that bone loss in the lumbar spine begins before menopause and is accelerated markedly by menopause for about ten years, and that menopause has a greater decreasing effect on the bone mass than does chronological age while each of them has an independent effect on the bone mass decrement.

Absorptiometry, Photon↗
PubMed1994

[Bone mineral density of lumbar spine and its relations to biological and lifestyle factors in middle-aged and aged Japanese women (Part 2). Effects of age and menopause on bone mineral density evaluated by biochemical markers of bone metabolism].

Bone mineral density of the lumbar spine (BMD) and biochemical markers for bone turnover were examined to study the mechanisms of age-related and menopause-related bone loss. We measured BMD of the lumbar spine and serum bone alkaline phosphatase (B-AIP) and bone gla-protein (BGP) as markers of bone formation and fasting urinary creatinine-adjusted hydroxyproline (Hyp/Cr) and calcium (Ca/Cr) as those of bone resorption in 166 community-dwelling Japanese women. A highly significant positive correlation between age and each of the biochemical markers, except for Ca/Cr, was observed. This relationship was not linear. Marked elevation in the levels of the markers was found in women in their sixth decade women compared with those in their fifth. All the markers correlated inversely with the BMD and these relationships remained significant after elimination of the effect of age by partialization. When analyzing the subjects in each five-year age group, the positive correlation of Hyp/Cr with Ca/Cr was significant in the subjects aged 45 to 49 and the negative correlation of Hyp/Cr with BMD was significant in those aged 50 to 54. B-AIP correlated positively with BGP in the subjects aged between 50 and 54 and inversely with BMD in those aged between 55 and 59. These correlations were significant. Thus, intercorrelations between the markers were observed five years earlier than were correlations between the markers and BMD. Such associations appeared earlier in terms of the markers for bone resorption than in terms of the markers for bone formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Human heart-type cytoplasmic fatty acid-binding protein in serum and urine during hyperacute myocardial infarction.

We have previously reported that serum and/or urinary human heart-type cytoplasmic fatty acid-binding protein (HH-FABPc) can be used as an early indicator of myocardial injury (Clin Biochem 1991; 24: 195-201). To confirm the usefulness of HH-FABPc as an early diagnostic indicator of acute myocardial infarction (AMI), its serum and urinary levels were measured in samples obtained within 6 h after the onset of acute coronary syndrome related symptoms. Samples were collected from 97 patients, who were composed of 63 with AMI, 24 with unstable angina and 10 with chest pain syndrome. The positivity of serum and urinary HH-FABPc and cardiac creatine kinase isozyme MB (CK-MB) was analyzed in these samples. Serum HH-FABPc levels in AMI were above normal in 91.4% (64/70) of the samples tested within 3 h of the onset of symptoms and in 100% (111/111) of those tested at 3-6 h. Elevated urinary HH-FABPc levels in AMI were obtained in 88.9% (8/9) of samples at 0-3 h and in 75% (6/8) at 3-6 h. CK-MB activity in AMI was positive in 20% (8/40) and 66.3% (53/80) of serum samples at 0-3 h and 3-6 h, respectively. HH-FABPc was always positive when a serum sample was positive for CK-MB. Serum HH-FABPc at 0-6 h in chest pain syndrome and in unstable angina were positive in 17.8% (5/28) and 56.7% (34/60), respectively. The elevated HH-FABPc in serum and urine was noted much earlier than that of CK-MB during the hyperacute phase of AMI. HH-FABPc showed high positive value in unstable angina, but it was low in normal coronary patients having chest pain. However, HH-FABPc level in unstable angina and chest pain syndrome was lower than that of AMI. Thus, HH-FABPc may be a valuable indicator for the diagnosis of hyperacute myocardial infarction.

Adult↗
PubMed1993

Autocorrelation of short-term and daily average exposure levels in workplaces.

Based on workplace exposure data for 16 worker-chemical combinations, the degree of autocorrelation in a series of short-term time-weighted average (TWA) exposure concentrations (7.5-min, 15-min, 30-min, and 60-min TWAs) was investigated. For 7.5-min and 15-min TWAs, consecutive values generally exhibited no correlation or positive correlation, but not negative correlation. Consecutive 30-min TWAs and 60-min TWAs showed either positive correlation, negative correlations, or no correlation. Autocorrelation functions displayed various patterns that depended on the exposure time series. The mean of the autocorrelation coefficients across all worker-chemical combinations was similar to an exponential function, which signifies that the degree of autocorrelation, on average, decreased as the interval between two averaging periods increased. Autocorrelation in a series of 8-hr TWAs also was analyzed for 10 worker-chemical combinations. In general, little autocorrelation was observed. Based on this analysis, the authors discuss a sampling strategy that, on average, would minimize the degree of correlation between measurements of short-term TWAs.

Chemical Industry↗
PubMed1993

Topographic differences of 1H-NMR relaxation times (T1, T2) in the normal intervertebral disc and its relationship to water content.

1H-nuclear magnetic resonance studies, in vitro, on normal intervertebral discs dissected from adult bovine (3- or 4-year-old) coccygeal vertebrae were performed to clarify topographic differences in relaxation times (T1, T2) and relationships between the relaxation times and water content. Immediately after death, intervertebral discs were dissected from 1st/2nd and 2nd/3rd coccygeal vertebrae and divided into three specimens: the nucleus pulposus, inner anulus fibrosus, and outer anulus fibrosus. T1, T2, and water content were measured for the specimens collected from 15 intervertebral discs (untreated group). Secondly, specimens were similarly collected from 12 intervertebral discs and were treated to changed water contents (dehydrated group and hydrated group). For each treated specimen, T1, T2, and water content were measured. The results showed highly significant differences (P < 0.01) in T1 values among the nucleus pulposus, inner anulus fibrosus, and outer anulus fibrosus, and also in T2 values between the nucleus pulposus and anulus fibrosus. In each of the nucleus pulposus and anulus fibrosus, a positive linear relationship (r = 0.97, P < 0.01) was found between T1 and water content. The respective regression lines for the nucleus pulposus and anulus fibrosus had different slopes, and the slope of the nucleus pulposus was significantly greater than that of the anulus fibrosus. Thus, the decrease in water content shortens the T1 in intervertebral discs, and changes in water content have a greater influence on T1 in the nucleus pulposus than in the anulus fibrosus.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗