Biomedical subjects

Yosei Fujioka

Publications and source records attributed to Yosei Fujioka.

9 recordsLinked to original sources

PubMed2006

Relationship between cumulative effects of smoking and memory CD4+ T lymphocyte subpopulations.

Previous studies have found that smoking is a strong factor that increases peripheral blood CD4+ T lymphocytes. However, most studies did not assess the cumulative long-life exposure of smoking on differential lymphocyte populations. In this study, to clarify the association of smoking habits and circulating lymphocytes, we conducted a cross-sectional study of 60 male current smokers. Smoking status was estimated by number of cigarettes smoked per day, smoking years, and Brinkman Index (BI) as calculated by multiplying the number of cigarettes smoked per day by the smoking years. Counts of CD4+CD45RO+CD69+ T and CD4+CD45RO+ T lymphocytes were strongly and positively correlated with BI and remained highly significant after controlling for alcohol drinking, leisure-time physical activity, and caffeine intake (r(p)>.465, p<.001). These lymphocytes were also significantly correlated with the number of cigarettes smoked per day and smoking years, but the association was weaker than the BI. The findings suggest that the CD4+CD45RO+CD69+ T and CD4+CD45RO+ T lymphocytes are sensitive to cumulative effect of smoking, and may serve as a potential immuno-biomarker for active smoking.

Adult↗

PubMed2006

Non-fatal occupational injury among active and passive smokers in small- and medium-scale manufacturing enterprises in Japan.

Active smoking is a risk factor for occupational injury, whereas its association with passive smoking is unknown. To evaluate the contribution of active and passive smoking to non-fatal occupational injury in manufacturing sectors, 2302 randomly selected workers aged 16-83 years working in 244 small- and medium-scale enterprises in Yashio city, Japan, were surveyed by means of a self-administered questionnaire. Smoking history, exposure to passive smoking, and occupational injury were evaluated by self-report. Exposure levels to passive smoking were assessed separately at work and at home as never, occasional, or regular exposure. Overall, 61.4% of men and 22.3% of women were current smokers. Among never smokers, 62.2% of men and 68.6% of women reported exposure to passive smoking either at work or home. Prevalence of occupational injuries was 36.2% for never, 43.3% for former, and 41.2% for current smokers among men and 19.7% for never, 22.2% for former, and 25.2% for current smokers among women. Among never smoking men, odds ratios (ORs) of occupational injury were 2.11 when regularly exposed to passive smoking at work or at home (p=0.025), 2.27 at work (p=0.015), and 3.08 at home (p=0.106), in comparison to never smoking men who were never exposed to passive smoking either at work or at home (referent group). These associations were attenuated to be non-significant, after controlling for potential confounders. Never smoking men with occasional exposure to passive smoking were not significant ORs (1.11-1.19). In contrast, current and former smoking men had significant increases in adjusted ORs (1.57-2.00). In women exposed to smoking there was a non-significant increase in occupational injury. The present study indicates an expected increase in the risk of, occupational injury for current and former smoking men and suggests that exposure to passive smoking is a possible risk factor for never smoking men.

Accidents, Occupational↗

PubMed2006

Impact of psychosocial job stress on non-fatal occupational injuries in small and medium-sized manufacturing enterprises.

BACKGROUND: Workers involved in manufacturing are known to comprise a high-risk population for occupational injury, and this risk is greater in small and medium-sized enterprises (SMEs). The purpose of this study was to examine the association between psychosocial job stress and occupational injuries among workers in SMEs. METHODS: One thousand forty-nine men and 721 women from 244 SMEs participated in this study. Perceived job stress was evaluated with the Japanese version of the generic job stress questionnaire, which covered 14 job stress variables. Occupational injury was assessed by self-report during the last 1-year period. RESULTS: Workers with high quantitative workload (odds ratio [OR] = 1.55 for men, 1.62 for women), high cognitive demands (OR = 1.70 for men, 1.53 for women), and low job satisfaction (OR = 1.33 for men, 1.93 for women) had a significantly increased risk of occupational injury in the multivariate model. High variance in workload (OR = 1.70) and high job future ambiguity (OR = 1.35) in men, and low job control (OR = 2.04) and high intragroup conflict (OR = 1.66) in women were significantly associated with occupational injury. In manufacturing/production workers, high quantitative workload (OR = 1.91), high variance in workload (OR = 2.02), and high depressive symptoms (OR = 1.55) were significantly associated with injury in men, while low social support from colleagues (OR = 2.36) or family (OR = 2.51) was related to injury in women. CONCLUSIONS: These data point to an independent relationship between psychosocial job stress and self-reported occupational injury in SMEs.

Accidents, Occupational↗

PubMed2006

The prevalence and correlates of occupational injuries in small-scale manufacturing enterprises.

Workers involved in small-scale manufacturing businesses are known to comprise a high-risk population for occupational injury. The present study investigated the prevalence and correlates of occupational injury in this population. A self-administered questionnaire that solicited answers about occupational information including injury, demographic characteristics, health conditions and lifestyle factors was collected from a sample of 1,298 workers in 228 small-scale manufacturing enterprises (defined as fewer than 50 workers) aged 16-78 (mean 46) yr in Yashio city, Saitama, Japan (response rate 65.5%). The enterprises were randomly selected from the 2000 edition of the city commercial directory corresponding to the distribution of types of businesses in the city. Occupational injury was assessed by asking subjects, ;Have you ever been injured during your work, including minor scratches and cuts in the previous 1-yr period?' The possible response was either ;yes' or ;no.' The prevalence of study-defined occupational injury among the workers was 35.6% (male 43.0%, female 17.9%). Among job types, manufacturing (44.2%) and driving (43.5%) had high rates of occupational injuries. Similarly, occupational injuries were high in the papermaking (54.5%) and machinery (47.7%) industries. For males, younger age, current or former smoking, insomnia symptoms, and disease(s) currently under treatment were correlated with injury, whereas for females, being unmarried, higher educational status, and insomnia symptoms were the correlating factors. Occupational injury is common among small-scale manufacturing businesses, and is associated with multiple controllable factors. Countermeasures such as prohibiting smoking during work, sleep health education, job safety training for young/inexperienced workers are appropriate methods for eliminating or reducing injuries.

Accidents, Occupational↗

PubMed2005

Sleep-related risk of occupational injuries in Japanese small and medium-scale enterprises.

A cross-sectional study evaluated the contribution of daily sleep habits to occupational injuries. A self-administered questionnaire solicited answers about sleep, symptoms of depression, occupational injury, demographics, presence of diseases and lifestyle factors from 2,903 workers between the ages of 16-83 (mean 45) yr in small and medium-scale enterprises. Eight sleep habits were queried and dichotomized: 1) less or more than 6 hr of daily sleep, 2) taking more or less than 30 min to fall asleep (Difficulty initiating sleep; DIS), 3) awakening during sleep more or less than 3 times/wk (Difficulty maintaining sleep; DMS), 4) early morning awakening more or less than 3 times/wk (EMA), 5) definitely/somewhat difficulty waking up or not, 6) sleeping very poorly/not so well at night or not, 7) definitely/somewhat insufficient nightly sleep or not, and 8) difficulty in breathing during sleep more than once/week or less. Occupational injury was assessed by asking subjects 'Have you ever been injured during your work, including minor scratches and cuts (Yes/No)?' Both sleep and injury were assessed over the previous one year period. One-third of workers answered that they had experienced injury. Workers with sleep features of DIS, sleeping poorly at night, insufficient sleep, and insomnia had a significantly higher prevalence for injury after adjusting for multiple confounders. The findings suggest that poor nocturnal sleep habits are associated with self-reported occupational injury.

Accidents, Occupational↗

PubMed2004

Association of sickness absence with poor sleep and depressive symptoms in shift workers.

A cross-sectional study was conducted to evaluate the contribution of daily sleep habits and depressive symptoms to sickness absences of shift workers. A self-administered questionnaire that solicited answers about sleep, symptoms of depression, sickness absence, diseases/injuries, and lifestyle factors was submitted to a sample of 522 rotating shift workers between the ages of 18-59 (mean 27) yrs of an electric equipment manufacturing company. The seven features of sleep queried were daily hours of sleep, time to fall asleep, awakening during sleep, early morning awakening, sleep well at night, sufficiency of sleep, and excessive daytime sleepiness at work. The responses were assessed over the subject's previous 1-yr period. Each sleep feature, except daily sleeping hours, was dichotomized by the following responses: (1) taking more than 30min to fall asleep (difficulty initiating sleep; DIS), (2) awakening during sleep almost every day (difficulty maintaining sleep; DMS), (3) early morning awakening almost every day (EMA), (4) sleeping very poorly or not so well at night, (5) definite or somewhat insufficient nightly sleep, and (6) excessive daytime sleepiness at work almost every day (EDS). Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale. Sickness absence was calculated by asking subjects "How many days in total have you been absent from work due to sickness, including paid vacation, in the last 1-yr period?" The responses were divided into three groups that included no (0 days) sickness absences (reference group, n=235 subjects), 1 to 4 days (short-term, n=199 subjects), and 5 days or more (long-term, n = 88 subjects). Compared to the prevalence of sleep features of the reference group, workers with short-term absence showed a significantly higher prevalence of EMA with an odds ratio (OR) of 5.3, 95% confidence interval (CI) 1.3-22.0. Long-term absence was significantly associated with DMS (OR = 2.1, 95%CI 1.0-4.6), EMA (OR = 5.6, 95%CI 1.0-28.7), sleeping poorly at night (OR= 2.6, 95%CI 1.4-5.0), and high depressive symptoms (OR = 2.0, 95%CI 1.0-3.7) according to the CES-D score of >16, after adjusting for multiple confounding variables. These data point to an association between both the parameters of poor sleep and symptoms of deep depression when self-reported sickness absence is frequent. The association is particularly strong with long-term absence in male shift workers.

Adolescent↗

PubMed2004

Effects of static load on the weight and protein content in the leg muscles of the mouse: a simulation of prolonged standing in the workplace.

To simulate the effects of prolonged standing in the workplace on the leg muscles, we subjected mice to centrifugation for 6 wk. The absolute wet weight of leg muscles and internal organs of mice were measured after exposure to 3G by centrifugation for 6 wk and at 2 wk after removal of centrifugation. The weight of the soleus muscle (antigravity muscle) significantly increased after 6-wk exposure to centrifugation, but it decreased to its control weight 2 wk after removal of centrifugation. In contrast, the wet weights of the anterior tibial muscle, liver, and kidneys of mice centrifuged for 6 wk were significantly lower than those of the control mice; they had returned to control levels 2 wk after removal of centrifugation. It was therefore suggested that prolonged standing enlarged the leg muscles but its effect did not last for a long period of time after stopping prolonged standing. Western blot analysis of proteins extracted from the soleus muscle showed that vinculin and alpha-actinin in the centrifuged mice increased slightly, but there were no differences in the heat shock protein 70 (HSP70) and desmin levels between the centrifuged mice and control mice. No difference in HSP 70 suggested that muscle damage did not exist after 6 wk centrifugation.

Animal Experimentation↗

PubMed2003

[The effect of chronic stress on neutrophil function in tumor-inoculated rats].

OBJECTIVES: In order to clarify the relation between stress load and inoculated tumor growth in conjunction with neutrophil functions, several kinds of stress such as physical (Ph) and psychological (Ps) stress were loaded on rats either SST-2 tumor cell inoculated or control, and the functions of their peripheral neutrophils were determined. METHODS: A communication box was used for stress load on rats. SST-2 cells were inoculated in to rats in the tumor-inoculation groups. Two weeks after inoculation, the tumors were removed from the backs of the rats and weighed. The functions of neutrophils in the peripheral blood collected from the tail vein, were determined by the NBT deoxidization method. RESULTS: Tumor growth was enhanced when rats were loaded with either Ph or Ps stresses, but was inhibited when tumor cells were inoculated following either Ph or Ps stresses. These results show that chronological differences of loaded stresses influence immunological functions differently. The O2- production from the neutrophils stimulated by NBT-treated Staphilococcus aureus was suppressed in tumor-inoculated Ph and Ps groups, more markedly in the tumor-inoculated Ph group. It is logically relevant that the size of tumors increased in these groups, predominantly in the tumor-inoculated Ph group. On the other hand, O2- production from the neutrophils was enhanced and tumor growth decreased in tumor-inoculated animals following either Ph or Ps stresses. CONCLUSIONS: Our experiments, it revealed that the function of neutrophils is strongly enhanced by stress load and O2- production is inhibited by the tumor inoculation as shown in stimulation tests. Therefore, our findings suggested that neutrophils may participate in the inhibition of tumor growth.

Animals↗

PubMed2002

Association of low job control with a decrease in memory (CD4+ CD45RO+) T lymphocytes in Japanese middle-aged male workers in an electric power plant.

To clarify the relationship between perceived job stress and lymphocyte subpopulations, a cross-sectional study was conducted in 231 male electric power plant workers (aged 40 to 60, mean 46 years). Job stress, i.e., job control, job demands, and social support at work, was assessed by means of the Japanese version of the Job Content Questionnaire. Blood samples were taken from all the workers, and numbers of CD4+ T lymphocyte subpopulations, total CD4+ T, T (CD3+) lymphocytes, CD16CD56+ natural killer (NK) cells, total lymphocytes, and white blood cells were determined. After controlling for age, number of cigarettes smoked per day, alcohol drinking, frequency of regular exercise, job demands, and social support at work by the partial correlation coefficients, numbers of memory (CD4+ CD45RO+) T, total CD4+ T, and total T (CD3+) lymphocytes were positively correlated with job control (p<0.05). Neither job demands nor social support at work showed significant correlations with lymphocyte subpopulations. It is suggested that lower job control is associated with a decrease in the number of CD4+ CD45RO+ T lymphocytes in male middle-aged workers.

Adult↗