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Biomedical subjects

R Kishi

Publications and source records attributed to R Kishi.

At least 37 records · Page 2Linked to original sources
PubMed2001

[A review of epidemiological studies on the relationship of social networks and support to depressive symptoms in the elderly].

This paper reviews evidence concerning the relationship of social support and networks to psychological well-being in elderly people. Although few studies have used comparative concepts and featured measurements of social networks and social support, the overall findings are that depressive symptoms in elderly people are associated with (a) smaller size of social networks which are supportive, (b) lower emotional support which is anticipated or received, (c) lower instrumental support which is anticipated, and (d) not providing support to others, and that depressive symptoms are greater when the amount of received instrumental support is larger. There is evidence consistent with both direct effects of social networks and support on reducing depressive symptoms, and buffering effects to protect persons from adverse effects of stressful life events. In addition, physical health status, activities of daily living, income, and marital status are associated with depression among the elderly. A well-conducted longitudinal study is essential for research in this area in Japan.

Aged↗
PubMed2000

Absence of association between a common mutation in the methylenetetrahydrofolate reductase gene and preeclampsia in Japanese women.

An association between preeclampsia (PE) and a common missense mutation of the methylenetetrahydrofolate reductase gene (MTHFR), a C to T substitution at nucleotide 677 (C677T), which converts an alanine to a valine residue, has been reported in Italian and Japanese populations. We examined 101 cases of hypertension in pregnancy (HP), including 73 cases of PE, and 215 normal pregnancy controls to confirm the association in Japanese women. No significant differences of the frequency of the T677 allele frequency or percentage of T677 homozygotes were detected among the various types of cases: HP (0.38, 12%, respectively), severe HP (0. 40, 12%), PE (0.38, 11%), severe PE (0.41, 11%), primiparous HP (0. 40, 12%), primiparous PE (0.44, 18%), nonelderly HP (0.39, 13%), nonelderly PE (0.40, 14%), nonobese HP (0.38, 12%), nonobese PE (0. 39, 10%), HP without homozygous T235 of the angiotensinogen gene (TT of AGT) (0.38, 15%), PE without TT of AGT (0.38, 15%), and controls (0.38, 15%). The results indicate that T677 of MTHFR may not be a risk factor for PE in Japanese population.

Adult↗
PubMed2000

Impairment of neurobehavioral function and color vision loss among workers exposed to low concentration of styrene--a review of literatures.

Recently many studies on the health effects of workers who exposed to low-concentration styrene have been published. In this paper firstly we mentioned the reasons why nervous system was critical organ for evaluating the toxicity of organic solvents both in the acute and chronic exposure phases. Then we indicated how neurobehavioral test batteries were useful to detect subclinical adverse health effects of workers exposed to organic solvents. Secondly we reviewed many epidemiological studies on the impairment of neurobehavioral function, i.e., perceptual speed, memory, cognition, personality and mood, and the loss of color vision among styrene workers. Finally, we showed our recent data on the relationship between color vision loss and the concentration of urine metabolites among styrene workers. It can conclude that styrene may cause damage on nervous system, even at the low exposure level such as 50 ppm which used to be the Threshold Limit Value (TLV) recommended by Japan Society for Occupational Health (until 1999) and American Conference of Industrial Hygienists (until 1997).

Affect↗
PubMed1999

Association of a variant of the angiotensinogen gene with pure type of hypertension in pregnancy in the Japanese: implication of a racial difference and significance of an age factor.

The contribution of genetic factors to hypertension in pregnancy, including pre-eclampsia, has been well documented. The association with a common molecular variant of the angiotensinogen (AGT) gene, in which methionine (M235) is substituted for threonine (T235) at residue 235, has been reported in both Caucasians and Japanese. In the present study, we examined 115 cases of pure type of hypertension in pregnancy (PHP) and 381 normal pregnant controls in order to look for subgroups in which the AGT gene is the major factor in the PHP pathogenesis. By classification of PHP cases according to the clinical diagnosis, gravidity, and maternal age, we found significantly higher frequencies of T235 in both all PHP patients and preeclampsia/eclampsia patients than in normal controls. These results are discordant with those reported for Caucasian subjects where only a group of preeclamptic primigravidae was associated with the AGT variant, possibly indicating the existence of a racial difference. We also found that the variant frequency was significantly higher in the PHP subgroup with maternal age of 20-34 years (0.93) than in a subgroup of multigravid PHP patients age 35 years or older (0.77, P < 0.05) or in normal controls of age 20-34 years (0.76, P < 0.001). The result indicates that the AGT variant plays a significant role in hypertension in the age group 20-34 years.

Adult↗
PubMed1999

Effects of prenatal exposure to styrene on neurochemical levels in rat brain.

Styrene was evaluated to determine its neurochemical effects in the offspring of rats exposed during the gestation period. Maternal Wistar rats were exposed to 0, 50 or 300 ppm styrene during gestation days 6 to 20 and the neurochemical effects on their offspring were compared with their pair-feeding and ad lib. feeding controls. The cerebrum weights at birth on day 0 were significantly lower than those for an ad lib. feeding control group. Neurotransmitter analyses showed decreases of neuroamines, especially 5-hydroxytryptamine and homovanillic acid in the cerebrum of newborn offspring of dams receiving a 300 ppm styrene exposure compared with the ad lib. fed control group and homovanillic acid was also decreased compared to the pair-feeding control. On postnatal day 21, the styrene-exposure pups showed a significant decrease of 5-hydroxyindoleacetic acid in the frontal neocortex compared with the ad lib. control group. In the hippocampus a significant decrease of 5-hydroxyindoleacetic acid was observed compared with both control groups. Moreover, the ratio of 5-HIAA/5-HT in the hippocampus was significantly decreased among the styrene-exposure groups. The 50 ppm styrene exposed group induced increase of concentrations of 5-hydroxytryptamine in the striatum. These results suggest that prenatal styrene exposure affects the developing fetal brain in terms of a few signs of neurochemical alteration.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1999

The factor V Leiden mutation is not a common cause of pregnancy-induced hypertension in Japan.

Recent studies in Caucasian populations have shown an association of the Leiden mutation in factor V with preeclampsia (PE). It consists of a substitution of a G (G1691) with an A (A1691) at nucleotide position 1691 in exon 10, resulting in arginine instead of glutamine at residue 506 at the factor V cleavage site for activated protein C (APC); it contributes to the resistance to APC. The purpose of this study was to determine whether the Leiden mutation is associated with pregnancy-induced hypertension (PIH), including PE, in Japanese women. We examined the genotypes of factor V of 71 Japanese patients with PIH and 109 controls. None of the 180 Japanese women carried the factor V Leiden mutation. To date, the factor V Leiden mutation is rare and not a common cause of PIH in Japan. The results may suggest that there is a significant ethnic difference in the role of the Leiden mutation in compounding the risk factors in the pathogenesis of PIH between Japanese and Caucasian populations.

Activated Protein C Resistance↗
PubMed1996

Study of urinary mandelic acid concentration and peripheral nerve conduction among styrene workers.

The relationship between exposure to styrene and nerve conduction velocities was investigated in 32 workers occupationally exposed to styrene. There was a dose-dependent relationship between urinary mandelic acid and ulnar and peroneal motor distal latencies (MDLs). The ulnar and peroneal MDLs of subgroup B (urinary mandelic acid > or = 250 mg/l) were significantly longer than those of subgroup A (urinary mandelic acid < 250 mg/l)(p < 0.05), and the referent group (p < 0.03). After adjusting confounding factors, urinary mandelic acid had a significant positive relationship with ulnar and peroneal MDL. Our study suggests that a low level of styrene, below the 50 ppm exposure limit of the American Conference of Governmental Industrial Hygienists (ACGIH), involves the risk of inducing adverse effects on the peripheral nervous system. The study also indicated that motor distal latency is a sensitive parameter of toxic peripheral neuropathy.

Action Potentials↗
PubMed1996

Investigation on neurotoxicity of occupational exposure to cyclohexane: a neurophysiological study.

OBJECTIVES: To examine the effect of occupational exposure to cyclohexane on the peripheral nervous system. METHODS: A nerve conduction study was performed on 18 workers exposed to cyclohexane in a luggage factory and on age and sex matched occupationally unexposed controls. 12 workers had been exposed to n-hexane (median 2.8 years) before the start of exposure to cyclohexane. To confirm the effect of exposure, a follow up study was performed on nine workers one year after the first study. The mean exposure to cyclohexane was 1.2 years in the first study. A symptom survey was performed. The exposure was measured by air sampling of the breathing zone of each worker. The urinary metabolite cyclohexanol was also monitored. RESULTS: The concentration of airborne cyclohexane ranged from 5 to 211 ppm. The urinary concentration of cyclohexanol ranged from 0.12 to 1.51 mg/l. There was a strong correlation between the cyclohexane exposure in personal air and urinary cyclohexanol. No differences were found in nerve conduction velocities (NCV) between workers exposed to cyclohexane and age and sex matched controls. The results of the follow up study showed significant improvements in peroneal motor NCV (P < 0.01) and sural sensory NCV (P < 0.05) and in ulnar motor distal latency (MDL, P < 0.05) and peroneal MDL (P < 0.05) compared with the first study. Although the past n-hexane exposure affected the first neurophysiological study, the effect had disappeared in the second study, one year later. CONCLUSION: Occupational exposure to the concentrations of cyclohexane experienced in this study had no adverse effects on the peripheral nervous system.

Adult↗
PubMed1996

[Risk factors in serologically diagnosed echinococcosis--a case control study in the Nemuro region of Hokkaido Prefecture].

To determine the risk factors for echinococcus infection, we conducted a case-control study in the Nemuro region of Hokkaido Prefecture. The cases included both clinically diagnosed patients with echinococcosis and registered persons who were seropositive. The control group was matched by residence, age (+/- 5 years) and sex. The data on the 99 cases and 430 controls were collected by mailed questionnaire. Because of the long latency of echinococcosis, we investigated the potential risk factors over two different periods-from 11-20 years before the time of registration, and from 10 years before the registration to the time of registration. For the 11-20 years before registration period, using well water as drinking water and cattle raising significantly increased the risk of echinococcosis. In the period 10 years before registration to the time of registration, hog raising also increased the risk. In contrast, drinking tap water decreased the risk. These results suggest the importance of a screening program, especially targeting people engaged in dairy farming and hog raising, as well as the need for extension of tap water services and health education on refuse disposal.

Adult↗
PubMed1996

[Effects of age and skin temperature on peripheral nerve conduction velocity--a basic study for nerve conduction velocity measurement in worksite].

The purpose of this study was to investigate the relation between nerve conduction velocity (NCV) and some factors which affect the measurement, such as age, skin temperature, body build and alcohol consumption. Neurophysiological parameters of healthy volunteers (28 males and 27 females, aged 20-57 years) who were free from occupational exposure inducing neuropathy were determined by monitoring skin temperature. A questionnaire survey on height, alcohol and tobacco consumption was also performed. The following results were obtained: 1) Analysis of covariance to examine the relation between age groups and NCVs adjusting for skin temperature showed significant differences only in peroneal motor distal latency (MDL) and duration of sural sensory nerve action potential (SNAP) between age groups. However, there was no constant relation between these parameters and age. Multiple regression analysis showed the significant relationships between age and ulnar MDL and the duration of sural sensory nerve action potential, adjusting for sex, height, weight, BMI, alcohol intake (frequency/week, ethanol equivalent ml/week), tobacco consumption (/day), skin temperature and education years. 2) The skin temperature had significant effects on ulnar MDL, ulnar sensory NCV, duration of ulnar SNAP, sural sensory NCV and amplitude and duration of sural SNAP according to the results of multiple regression analysis and analysis of variance. 3) The body mass index had an independent effect on the ulnar nerve conduction, shortening MDL and the duration of the sensory nerve action potential. 4) Consumption of alcohol and tobacco had no significant relation to nerve conduction velocity in our study. These results show that skin temperature is a major covariate of peripheral nerve conduction and that it is very important to control skin temperature in studies on nerve conduction measurements.

Adult↗
PubMed1996

[Health status, social networks and support systems of so called old old in a population-based comparative study of residents ages 69-74 and 75-80].

To analyze the different features of health status, social support and networks of elderly people by age groups, a survey was performed of the social environment and health related issues among residents aged 69-74 and 75-80, the so called old-old, in Takasu, a small farming town in Hokkaido. The results were as follows: 1. The percentage of elderly having some of the symptoms related to dementia, lower scores of ADL, and poorer conditions of eye sight or hearing were significantly higher among the elderly aged 75-80 compared to those aged 69-74. The prevalence of diseases, such as senile cataracts in both sexes, and heart diseases in men were also higher among those aged 75 and over. 2. Although there were no differences in the mean number of hospital admissions or in the percentage of those having been sick in bed for more than 1 week during the previous one year, both the mean number of out-patient visits and percentage having a family physician were significantly higher in the elderly over 75 than under. Deterioration of IADL were prominent in the item on being able to go far away by themselves. 3. Almost 70% of the elderly participated in community-based social activities in Takasu. There were only small differences in social support and network among the different categories of family structure of the elderly. However women over 75 had statistically significantly lower number of the social supports compared to the younger age groups. A significantly smaller percentage of people was able to obtain the emotional or care support from their spouse for in elderly over 75 than for elderly under 75. 4. The results of this study suggest the need to provide more social support and networks for the old-old over 75 years old who tend to have more diseases and to be in poorer health condition, both physically or mentally than younger old.

Aged↗
PubMed1995

Impaired colour discrimination among workers exposed to styrene: relevance of a urinary metabolite.

OBJECTIVES: To survey the loss of colour vision among Japanese workers who have been exposed to styrene concentrations currently considered low (about 20 ppm). Also to assess the effects of styrene by examination of the nature of the relation between disorder of colour vision and age, alcohol consumption, and other variables. METHODS: Colour discrimination was examined in 64 male workers exposed to styrene (mean age; 38.0, mean exposed years; 7.0) and in 69 controls (mean age; 38.0). A standardised questionnaire was adopted to collect work history, occupational or non-occupational solvent exposure, alcohol consumption, and drug use. Colour vision was evaluated by the Lanthony desaturated panel D-15 test. The results of the test were expressed as the colour confusion index (CCI). RESULTS: The mean atmospheric styrene concentration was about 20 ppm. The mean urinary concentration of mandelic acid was 0.22 g/l. There was a significant difference in CCI between exposed workers and age matched controls. Colour vision of workers whose concentration of urinary mandelic acid was > or = 0.42 g/l was significantly impaired when compared with workers whose concentration was < 0.42 g/l. Multiple linear regression analysis that controlled confounding variables such as age, alcohol consumption, smoking, and educational attainment showed that the CCI was significantly related to the concentration of urinary mandelic acid. In both exposed workers and controls, the types of defects were mostly blue-yellow loss, although a few subjects showed complex loss. No one showed only red-green loss. CONCLUSIONS: These findings suggest that exposure to moderate styrene concentrations can lead to impairment of colour vision, and that there is a significant correlation with the urinary metabolite of styrene.

Adult↗
PubMed1995

[Fatigue and stress of anesthesiologists at work--third report: investigation with a flicker photometer and a stabilo-meter].

We previously studied the fatigue and stress of anesthesiologists at work using a flicker photometer, visual reaction time test, questionnaires, and Holter EKG. In the present study, we investigated the fatigue and stress in seven junior anesthesiologists at work using a flicker photometer and a stabilo-meter. The stabilo-meter measures postural stabilization. We performed each test three times on each subject for a total of twenty-one times. The flicker test and the stabilo-test showed the increase in fatigue in 17 (18%) and in 16 tests (76%), respectively, in all seven subjects. Increase of fatigue in both the flicker and stabilo-tests was observed in 13 tests (61%) of 6 subjects. There was a good relationship between the flicker test and the stabilo-test. Therefore, the stabilo-test appears to be a useful method for investigating the fatigue of anesthesiologists.

Anesthesiology↗
PubMed1995

[A comparative study of public knowledge and awareness of echinococcus in relation to anti-echinococcus policies of towns in Hokkaido].

A population-based comparative study was performed on public awareness and knowledge about the risk of Echinococcosis and the life habits of the people living in 2 towns in eastern Hokkaido, Bekkai and akan. Bekkai has had an anti-echinococcosis policy and Akan has only limited experiences with such countermeasures. The results of the survey were as follows: 1) Compared with the inhabitants in the town of Akan, the residents in Bekkai had significantly higher correct response rates for many questions concerning parasitological knowledge and the risks of echinococcosis, and knew about subjects such as the pathogen, latency period, susceptible organs, the prognosis, the possibility of transmission of echinococcosis from human to human and methods for the sterilization of eggs from infected animals. 2) The rate of correct answers to such questions were approximately 70 to 90% in both towns. However the percentage of correct answers to questions about carrier animals and the question of human susceptibility were relatively low, ie., 45% and 20%, respectively, even in Bekkai. 3) The residents of Akan knew more about carrier animals of echinococcosis than the inhabitants of Bekkai. In Akan woman and persons in their 20's and 30's had lower rates of correct answers. Further health education should be aimed toward such people. 4) Foxes appeared near private homes more frequently in Akan than in Bekkai. More inhabitants of Akan used spring water as drinking water than in Bekkai, while more inhabitants used tap water as drinking water in Bekkai. Only a few inhabitants paid attention to how to prepare vegetables for cooking. This information suggests that echinococcosis may spread in Akan in the near future. 5) Our results suggest that better organized health education programs, the extension of tap water services in Akan, and the establishment of proper methods for disposal of garbage and the afterbirth of cattle are necessary to reduce the presence of foxes in inhabited areas.

Adult↗
PubMed1994

Exposure monitoring and health effect studies of workers occupationally exposed to cyclohexane vapor.

A survey was conducted in the second half of a working week on 33 women who either applied glue (with cyclohexane as an almost exclusive solvent component) or worked in the vicinity of glue application. Carbon cloth-equipped diffusive samplers were used for personal measurement of time-weighted average intensity of exposure to the solvent. The geometric mean and the highest cyclohexane concentration observed in air were 27 ppm and 274 ppm, respectively. Concentrations of cyclohexanol in urine samples and cyclohexane in whole blood and serum collected at the end of a shift showed significant correlations with the solvent exposure levels. Urinary cyclohexanone also correlated, but with a smaller correlation coefficient. The observation suggests that cyclohexanol in urine and cyclohexane in blood or serum collected at the end of a shift are useful indicators of occupational exposure to cyclohexane vapor. Quantitative estimation of balance at the end of the shift suggested that only a minute portion (< 1%) of cyclohexane absorbed is excreted in the urine as cyclohexanol, almost exclusively as a glucuronide. A survey of subjective symptoms revealed an increase in the prevalence of "dimmed vision " and "unusual smell", but hematology and serum biochemistry testing did not indicate any specific signs.

Adult↗
PubMed1994

Residual neurobehavioural effects associated with chronic exposure to mercury vapour.

To find the residual effects of long term exposure to mercury vapour, neurobehavioural tests were given to ex-mercury miners about 18 years after the end of mercury exposure. Seventy six male ex-mercury miners who had been exposed to high concentrations of mercury vapour (over 1.0 mg/m3) and with a history of mercury intoxication were compared with controls matched for age (within 3 years), sex, and education. Although the extent of the workers' symptoms caused by mercury poisoning, termed erethismus merculialis, decreased considerably after the end of exposure, matched paired comparison showed that performances of motor coordination, simple reaction time, and short term memory had deteriorated significantly in the exposed group. Multiple linear regression analysis of exposure variables with neurological examination measures showed positive correlations between poorer neurological performance and variables related to mercury exposure. Thus the duration of exposure correlated with poorer performance of hand-eye coordination, tapping, and a colour card reading test. Job categories classified by exposure to mercury also had a significant negative correlation with these performances. The period of years after the end of exposure had a significant correlation with better performance of reaction time and digit span. On the other hand, the history of intoxication itself had no significant correlation with any of the current neurobehavioural performances. These results suggest that there are slight but persistent effects on neurobehavioural function, especially on motor coordination, among mercury miners even more than 10 years after the end of exposure.

Aged↗