Objectives: Many studies have been reported on adverse effects of sleep loss upon health. However, there are some discrepancies regarding the effect of sleep loss upon brain functions, and additionally, the study on the recovery process after sleep loss is insufficient. On the other hand, the study on the relationship between sleep and oxidative stress, which is related to many diseases, such as cancer, arteriosclerosis and depression, has been reported in recent years. It is useful to clarify the etiology of health disorders induced by sleep loss. Methods and Results: We investigated how subjective sleepiness, mood states, simple and cognitive performance changed after one night of sleep deprivation (SD). In another study, we investigated the change of several biological indicators after SD, 8-Hydroxy-deoxyguanosine (8-OH-dG), as an oxidative stress marker, and blood pressure and plasma cortisol. Subjective sleepiness nearly recovered to the baseline level on the 1st recovery day by 1 ordinary recovery sleep (7 hours) opportunities. Moods of fatigue and confusion, and high cognitive function seemed to need more than 2 ordinary recovery sleep opportunities to return to the baseline. A significant decrease of plasma cortisol at 7 AM and a slight but no significant increase of blood pressure, and no significant change of the urinary 8-OH-dG level after SD were observed. Conclusion: These results suggest that the recovery process after SD may differ among subjective sleepiness, mood and cognitive function, and 2 recovery sleep opportunities may be needed for the recovery of fatigue and high cognitive functions, and also circadian rhythm may disturbed after SD. It's necessary in the occupational safety and health to consider the prolonged adverse effect due to sleep loss.

View full abstract

A lot of studies have reported on the relationship between job stress and some diseases. Some Japanese studies reported in which working hours can be a risk factor for acute myocardial infarction and shift work for ischemic heart disease of male workers. The mechanisms which link overwork to health problems have also been studied. We've come to consider the autonomic nervous system as this mechanism. In this study, the cardiac parasympathetic function during sleep as an ability to recover with rest was examined among healthy male shift workers, who usually work night shifts during the whole year except 2 or 3 months, in order to investigate the effect of shift work upon the autonomic nervous system. The subjects were 9 men (46.3±4.2 years old) working a split sift for an electronics manufacturing corporation. They wore a pulse wave sensor and switched it on before bed time and switched it off and remove it after awaking. The measurement periods were two weeks each of the following four terms: beginning of day shift, ending of day shift, beginning of night shift, and during night shift. High frequency component (HF) of pulse rate variability was measured using power spectrum analysis. The mean value of HF during one continuous sleep was considered as the representative value of the sleep, which was used as the index of cardiac parasympathetic function during sleep. Each comparison of the mean value of HF of each term to that of beginning of day shift was compared by using two-way ANOVA. Although the comparison of the mean value of HF during sleep of nonworking day didn't differ in each term, the one of working-day in each during night shift was higher than that of beginning of day shift and that of ending of day shift. It was suggested that the cardiac parasympathetic function during sleep could be effected with shift work.

View full abstract

There is a need for an organizational approach that ensures occupational mental health promotion with sustainable effects. The improvement of work environment is the organizational approach to promoting workers' physical and mental health and their productivity. Active participation of workers is crucial to the sustainable and effective improvement of work environment. We developed MIRROR and WIN as questionnaires that were constructed from the positive items focused on workers' needs in order to facilitate their active participation and constructive consideration to improve the work environment. Studies on the relationship between psychosocial work environments, reduction of work stress, and mental health suggest that improving an organizational climate through PDCA cycle utilizing the questionnaires, contributes to the promotion of workers' physical and mental health and their productivity. The task for the future is to popularize not only the reactive mental health care but also evidence-based proactive stress management.

View full abstract

Following the rising suicide rate and increase in work-related stress, the Ministry of Health, Labor and Welfare formulated "Guidelines for workers' mental health promotion "and has been promoting the efforts for mental health care in the workplace. Japan Labor Health and Welfare Organization has been active in supporting mental health promotion in the work-place, which is one of the resources outside of the workplace indicated as 4 types of care in the above guidelines. Japan Labor Health and Welfare Organization also designated "workers' mental health" as one of the 13 research areas which need to be focused on from the medical standpoint, and established the specialized research center in Yokohama Rosai Hospital to conduct 2 projects in research and development. In this article, Research Project 1, "Empirical Research for Effectiveness of Mental Health Check and Health Guidance using Internet" is described.

View full abstract

Objectives: Conventionally, it is reported that there are few people who are aware of a connection between premenstrual symptoms and menstruation in young females. However, young females who suffer from premenstrual symptoms are increasing recently. The purpose of this study is to investigate frequency of premenstrual symptoms and to construct scales with the symptoms. Method: 110 items with premenstrual symptoms were collected from precedent studies and a questionnaire relating to the symptoms was made up. The questionnaire by self-report was carried out to 184 college school girls. Results: More than 60% of the subjects were aware of stomachache or irritation on premenstrual phase. On the contrary, some 10% of the subjects had positive cognition of unpleasant symptoms on premenstrual phase. As a result of having made a factor analysis, six factors about the symptoms or cognition were extracted. The six factors were named as "depressive states", "lack of concentrations", "unpleasantness for the menstruation", "physical complaints", "positive cognition for the symptom" and "hormone-related symptoms" respectively. These factors are important as we construct a scale of premenstrual states in young females. Conclusion: This study suggested that even young females often suffer from premenstrual symptoms. In addition, it raises a new point of view for studies of premenstrual symptoms that some young females have positive cognition of premenstrual state. We will clarify the traits of young females with positive cognition of unpleasant symptoms, and develop the care or support for young females suffering from premenstrual symptoms.

View full abstract

Objective: The purpose of the present study was to examine the stages of change in behavior when wearing a mask among patients of lung tuberculosis (TB). Moreover, we examined differences along with each of the stages of change in terms of pros and cons, barriers and facilitators for mask wearing behavior, psychological adjustment, physical symptoms, and social factors. Method: The participants were lung TB patients or patients who might have lung TB in hospital. The design of the present study was a cross sectional design. Findings: In the participants of this study, there were twenty-two participants for the preparation stage and twenty-six participants for the action stage. We analyzed the data of the participants whose mean age was 53.09±16.70 (range was 19-78 years old). The results showed there were significant differences in some items of the cons and barriers for wearing a mask, and physical symptoms. It was identified that there were different tendencies in the length of hospital stay and facilitators for wearing a mask. In particular, there were significant differences in multiple items for barriers of wearing a mask. Discussion: In the future, not only should facilitators be promoted, but participants should also be reminded of wearing a mask if there are barriers for wearing a mask by medical staff, especially nurses. It is also preferable to intervene to stop patients from forgetting to wear a mask.

View full abstract