Impact of mercury discharged from submarine volcano on inner bay ecosystems.

Organic mercury, inorganic mercury and total mercury concentrations in phytoplankton (<0.1 mm) and zooplankton (>0.1 mm) collected in Kagoshima Bay, Japan were measured from 2017 to 2019 to estimate the impact of mercury discharged from submarine volcanoes on ecosystems; submarine volcanic activity continues at a depth of 200 m in the inner part of Kagoshima Bay. The total mercury concentrations in phyto- and zooplankton collected by vertical hauling at 0-200 m at just above the submarine volcano were in the range of 0.11-2.0 mg kg-1 (avg. 0.67 mg kg-1) and 0.090-0.56 mg kg-1 (avg. 0.21 mg kg-1), respectively. These values were one order of magnitude higher than the values in plankton collected in the central part of Kagoshima Bay. Organic mercury concentrations in phyto- and zooplankton were <0.010-0.071 mg kg-1 (avg. 0.028 mg kg-1) and 0.012-0.25 mg kg-1 (avg. 0.10 mg kg-1), respectively, for the inner part, and <0.010-0.040 mg kg-1 (avg. 0.010 mg kg-1) and <0.010-0.025 mg kg-1 (avg. 0.012 mg kg-1), respectively, for the central part. The values obtained in the inner part of the bay increased in summer and decreased in winter, which was consistent with changes in seawater mercury concentrations affected by volcanic activity. The organic mercury concentration in zooplankton collected just above the submarine volcano showed a size dependency, and a higher value was observed in the larger size, which suggested that the discharged mercury from the volcano was absorbed and concentrated through the ecosystem.

Prospective randomized study evaluating the usefulness of a surgical smoke evacuation system in operating rooms for breast surgery.

BACKGROUND: No prospective evaluation of surgical smoke evacuation systems has yet been conducted anywhere in the world. A prospective randomized study was conducted to clarify the usefulness of a surgical smoke evacuation system in terms of reducing the quantity of environmental pollutants found in operating room air and reducing the occupational exposure of doctors and nurses involved in surgical procedures to surgical smoke, volatile organic compounds, formaldehyde, etc. METHODS: Operating room environment conditions with and without the use of a surgical smoke evacuation system were measured, and the personal exposure levels of doctors and nurses involved in surgical procedures were also surveyed. Use of the evacuation system was determined randomly, and the procedures involved were breast-conserving surgery and mastectomy, which were treated as stratification factors. RESULTS: The average total volatile organic compound concentration in the operating room was significantly lower when the evacuation system was used compared with when it was not used. The findings were similar for formaldehyde concentration. Multiple regression analysis for healthcare professionals' personal exposure levels showed that the evacuation system was a factor that significantly impacted their formaldehyde and acetaldehyde personal exposure levels, which were greatly reduced by the use of the system. CONCLUSION: This study's findings demonstrate the effectiveness of the evacuation systems, which should increase awareness that their benefits take priority over the drawbacks. TRIAL REGISTRATION: The study was conducted after explaining to participants that it was a study of operating room environments in which their participation was voluntary and obtaining their consent. The study was also approved by the Tokai University Hospital clinical research review committee (no. 5R-022) and registered with the UMIN registry (UMIN000029092) on 13, September, 2017- retrospectively registered.

[Effects of Brief Cognitive Behavioral Therapy for insomnia on sleep and usage of hypnotics among community-dwelling older adults: Randomized controlled trial].

Objectives　Chronic insomnia is common in late adulthood. A non-pharmacological approach should take priority in the treatment of insomnia for the elderly. Many studies have shown the efficacy of Cognitive Behavioral Therapy for Insomnia (CBT-I) for elderly diagnosed with insomnia. However the effect of CBT-I on mild insomnia among older adults in community settings has not been ascertained. We conducted a randomized controlled trial to evaluate the effectiveness of a brief CBT-I delivered by nurses, which is feasible in community settings, to improve sleep quality and decrease the dose of hypnotics use for older adults.Methods　Participants aged 60 years and over were enrolled in this study. The participants in the intervention group were administrated the brief CBT-I consisting of a group session (60 min) and an individual session (30 min). The primary outcomes were the score differences in the Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI). The secondary outcomes were the change in the proportion of people diagnosed with insomnia and the dose of hypnotics used. The follow-up period was 3 months.Results　The score on PSQI in the intervention group (n=41) significantly decreased compared to the control group (n=38). The effect size (Cohen's d) was 0.56 (95% Confidence interval [CI], 0.07 to 1.05). The score on ISI also decreased significantly and Cohen's d was 0.77 (95%CI, 0.27 to 1.26). According to subgroup analysis, Number Needed to Treat (NNT) for improvement of insomnia was 2.8 (95%CI, 1.5-17.2) and NNT for decreasing of dose of hypnotics use was 2.8 (95%CI, 1.5-45.1).Conclusion　The present results have demonstrated that the brief CBT-I significantly improved subjective evaluation of sleep quality and insomnia symptoms among the elderly. In addition, the brief CBT-I decreased the usage of hypnotics. Further studies are needed in terms of the procedure and the effects of brief CBT-I for older adults living in a community.

USP10 Is an Essential Deubiquitinase for Hematopoiesis and Inhibits Apoptosis of Long-Term Hematopoietic Stem Cells.

Self-renewal, replication, and differentiation of hematopoietic stem cells (HSCs) are regulated by cytokines produced by niche cells in fetal liver and bone marrow. HSCs must overcome stresses induced by cytokine deprivation during normal development. In this study, we found that ubiquitin-specific peptidase 10 (USP10) is a crucial deubiquitinase for mouse hematopoiesis. All USP10 knockout (KO) mice died within 1 year because of bone marrow failure with pancytopenia. Bone marrow failure in these USP10-KO mice was associated with remarkable reductions of long-term HSCs (LT-HSCs) in bone marrow and fetal liver. Such USP10-KO fetal liver exhibited enhanced apoptosis of hematopoietic stem/progenitor cells (HSPCs) including LT-HSCs but not of lineage-committed progenitor cells. Transplantation of USP10-competent bone marrow cells into USP10-KO mice reconstituted multilineage hematopoiesis. These results suggest that USP10 is an essential deubiquitinase in hematopoiesis and functions by inhibiting apoptosis of HSPCs including LT-HSCs.

Relationships among indoor, outdoor, and personal airborne Japanese cedar pollen counts.

Japanese cedar pollinosis (JCP) is an important illness caused by the inhalation of airborne allergenic cedar pollens, which are dispersed in the early spring throughout the Japanese islands. However, associations between pollen exposures and the prevalence or severity of allergic symptoms are largely unknown, due to a lack of understanding regarding personal pollen exposures in relation to indoor and outdoor concentrations. This study aims to examine the relationships among indoor, outdoor, and personal airborne Japanese cedar pollen counts. We conducted a 4-year monitoring campaign to quantify indoor, outdoor, and personal airborne cedar pollen counts, where the personal passive settling sampler that has been previously validated against a volumetric sampler was used to count airborne pollen grains. A total of 256 sets of indoor, outdoor, and personal samples (768 samples) were collected from 9 subjects. Medians of the seasonally-integrated indoor-to-outdoor, personal-to-outdoor, and personal-to-indoor ratios of airborne pollen counts measured for 9 subjects were 0.08, 0.10, and 1.19, respectively. A greater correlation was observed between the personal and indoor counts (r = 0.89) than between the personal and outdoor counts (r = 0.71), suggesting a potential inaccuracy in the use of outdoor counts as a basis for estimating personal exposures. The personal pollen counts differed substantially among the human subjects (49% geometric coefficient of variation), in part due to the variability in the indoor counts that have been found as major determinants of the personal pollen counts. The findings of this study highlight the need for pollen monitoring in proximity to human subjects to better understand the relationships between pollen exposures and the prevalence or severity of pollen allergy.

[Features of occupational health nurse support for the improvement of psychosocial working environments and related factors: Focusing on required knowledge and skills, and measures to develop them].

OBJECTIVE: The purpose of this study was to examine the support activities provided for occupational health nurses aimed at improving psychosocial working environments, related knowledge and skills, and learning environments as well as associations among these factors. In addition, we aimed to create correlated factor models to describe the support activities in order to identify ways to promote these activities among occupational health nurses. METHODS: An anonymous mail-based questionnaire survey was conducted of occupational health nurses who were members of the Japan Society for Occupational Health and belonged to enterprises or independent health insurance societies. Among 356 returned questionnaires (response rate: 46.4%), all the main items were answered in 329 (valid response rate: 92.4%), and these questionnaires were analyzed. Factor analysis was performed for the seven items pertaining to support activities for the improvement of psychosocial working environments and models of each factor of the support activities were developed using covariance structure analysis. RESULTS: In the factor analysis, [Clarifying a stress-related situation and providing advice] and [Facilitating workplace involvement] were identified as support-related factors. The mean implementation rates for these approaches were approximately 50 to 80%, and less than 40%, respectively. [Clarifying a stress-related situation and providing advice] was associated with skills of "providing superiors with explanations to enhance their understanding" and "collecting and analyzing stress survey results by department", and knowledge of "personal stress questionnaires" and "common stress factors in working environments". The above-mentioned knowledge and skills were associated with self-learning of "examining and reporting daily activities for the improvement of working environments" and "reviewing related papers". [Facilitating workplace involvement] was associated with skills of "indirectly supporting discussions led by key persons in working environments" and "giving feedback regarding occupational stress survey results to superiors", and knowledge of "tools for the improvement of working environments" and "appropriate methods to use stress questionnaires". In addition, such knowledge and skills were associated with self-learning and learning environments of "participating in seminars to learn effective methods to use group-work approaches" and "receiving support and advice from mentors of universities and research institutions". DISCUSSION: The features of occupational health nurse support for the improvement of psychosocial working environments were revealed by this study. The implementation rates suggest that it is particularly necessary to promote [Facilitating workplace involvement]. It will be necessary to encourage the acquisition of associated knowledge and skills in order to promote occupational health nurse support for the improvement of psychosocial working environments.

A survey on bacterial contamination of lavage water in electric warm-water lavage toilet seats and of the gluteal cleft after lavage.

Electric warm-water lavage toilet seats are in wide use as an appliance beneficial for the maintenance of hygiene and the prophylaxis and improvement of conditions such as constipation and hemorrhoids. In this study, we surveyed the bacterial content in the lavage water of warm-water lavage toilet seats, and fecal bacterial contamination of the gluteal and genital regions due to droplet infection from post-defecation lavage, to examine the problems inherent to the use of such lavage units. The presence of viable bacteria in lavage water was confirmed in this survey. Viable bacterial counts in lavage water were 3-times higher in household units compared to units in public facilities, suggesting a correlation with the replenishment of lavage tank water with fresh water containing residual free chlorine.

A preliminary study on the use of meconium for the assessment of prenatal exposure to heavy metals in Japan.

In recent years, there has been increasing interest in the relevance of environmental pollution to children's health. We investigated whether the concentrations of heavy metals in meconium can be used for the assessmet of prenatal exposure in Japan. Our study subjects were newborns whose mothers were hospitalized for childbirth at Tokai University Hospital between November 2010 and March 2011. The target compounds of this study were lead (Pb), cadmium (Cd) and arsenic (As). Meconium samples collected from 102 newborns were analyzed using ICPMS. The median concentrations of Pb and As in the meconium were 0.71 ppb and 0.03 ppb, respectively. The median concentration of Cd was below the limit of quantification. These concentration values are much lower than those used in previous studies. Further study is needed to compare the concentrations of heavy metals in biological samples and to investigate the availability of meconium for the assessment of exposure to heavy metals during pregnancy.

HTLV-1 Tax oncoprotein stimulates ROS production and apoptosis in T cells by interacting with USP10.

Human T-cell leukemia virus type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia (ATL), and the viral oncoprotein Tax plays key roles in the immortalization of human T cells, lifelong persistent infection, and leukemogenesis. We herein identify the ubiquitin-specific protease 10 (USP10) as a Tax-interactor in HTLV-1-infected T cells. USP10 is an antistress factor against various environmental stresses, including viral infections and oxidative stress. On exposure to arsenic, an oxidative stress inducer, USP10 is recruited into stress granules (SGs), and USP10-containing SGs reduce reactive oxygen species (ROS) production and inhibit ROS-dependent apoptosis. We found that interaction of Tax with USP10 inhibits arsenic-induced SG formation, stimulates ROS production, and augments ROS-dependent apoptosis in HTLV-1-infected T cells. These findings suggest that USP10 is a host factor that inhibits stress-induced ROS production and apoptosis in HTLV-1-infected T cells; however, its activities are attenuated by Tax. A clinical study showed that combination therapy containing arsenic is effective against some forms of ATL. Therefore, these findings may be relevant to chemotherapy against ATL.

Both G3BP1 and G3BP2 contribute to stress granule formation.

Upon exposure to various environmental stresses such as arsenite, hypoxia, and heat shock, cells inhibit their translation and apoptosis and then repair stress-induced alterations, such as DNA damage and the accumulation of misfolded proteins. These types of stresses induce the formation of cytoplasmic RNA granules called stress granules (SGs). SGs are storage sites for the many mRNAs released from disassembled polysomes under these stress conditions and are essential for the selective translation of stress-inducible genes. Ras-GTPase-activating protein SH3 domain-binding protein 1 (G3BP1) is a component of SGs that initiates the assembly of SGs by forming a multimer. In this study, we examined the role of G3BP2, a close relative of G3BP1, in SG formation. Although single knockdown of either G3BP1 or G3BP2 in 293T cells partially reduced the number of SG-positive cells induced by arsenite, the knockdowns of both genes significantly reduced the number. G3BP2 formed a homo-multimer and a hetero-multimer with G3BP1. Moreover, like G3BP1, the overexpression of G3BP2 induced SGs even without stress stimuli. Collectively, these results suggest that both G3BP1 and G3BP2 play a role in the formation of SGs in various human cells and thereby recovery from these cellular stresses.

Human T cell leukemia virus type 2 (HTLV-2) Tax2 has a dominant activity over HTLV-1 Tax1 to immortalize human CD4+ T cells.

While human T cell leukemia virus type 1 (HTLV-1) is the causative agent of adult T cell leukemia, a close relative, HTLV-2, is not associated with any leukemia. HTLV-1 and HTLV-2 encode the Tax1 and Tax2 proteins, respectively, which are essential for the immortalization of human T cells by the respective viruses, thereby causing persistent infection. In this study, we compared Tax1 and Tax2 with respect to their immortalization activity in human T cells. Lentivirus-mediated transduction of the tax2 gene into human peripheral blood mononuclear cells stimulated with phytohemagglutinin and interleukin-2 in 96-well plates induced outgrowing T cells in most wells, but the cells infected with the control viruses died within 3 weeks. Surprisingly, the number of outgrowing cells induced by Tax2 was much higher than that induced by Tax1, and the appearance of outgrowing cells by Tax2 was earlier than that induced by Tax1. Nevertheless, both Tax2 and Tax1 preferentially immortalized CD4(+) T cells, but not CD8(+) T cells. Our study showed that HTLV-2 Tax2 can immortalize human CD4(+) T cells, and the activity is much higher than that of Tax1. The distinct T cell immortalization activities of Tax2 and Tax1 might therefore play a role in the different pathogeneses observed for these two viruses.

Stress granules inhibit apoptosis by reducing reactive oxygen species production.

Cells can undergo two alternative fates following exposure to environmental stress: they either induce apoptosis or inhibit apoptosis and then repair the stress-induced alterations. These processes minimize cell loss and prevent the survival of cells with aberrant DNA and protein alterations. These two alternative fates are partly controlled by stress granules (SGs). While arsenite, hypoxia, and heat shock induce the formation of SGs that inhibit apoptosis, X-ray irradiation and genotoxic drugs do not induce SGs, and they are more prone to trigger apoptosis. However, it is unclear precisely how SGs control apoptosis. This study found that SGs suppress the elevation of reactive oxygen species (ROS), and this suppression is essential for inhibiting ROS-dependent apoptosis. This antioxidant activity of SGs is controlled by two SG components, GTPase-activating protein SH3 domain binding protein 1 (G3BP1) and ubiquitin-specific protease 10 (USP10). G3BP1 elevates the steady-state ROS level by inhibiting the antioxidant activity of USP10. However, following exposure to arsenite, G3BP1 and USP10 induce the formation of SGs, which uncovers the antioxidant activity of USP10. We also found that the antioxidant activity of USP10 requires the protein kinase activity of ataxia telangiectasia mutated (ATM). This work reveals that SGs are critical redox regulators that control cell fate under stress conditions.

Additional candidates to conventional genes susceptible for lung cancer and changing trend in Japan.

The polymorphism of CYP1A1*2A or CYP1A1*2B, and the linkage of CYP1A1*2A, CYP1A1*2B, GSTM1 and GSTT1 polymorphisms have been established as susceptible genes or gene-gene interactions of tobacco-related lung cancer. New candidate genes susceptible for lung cancer such as NQO1 (NAD(P)H:quinine oxidoreductase), NAT2 (N-acetyltransferase 2), and several others have been reported. In the present review we focus on new candidate genes susceptible for lung cancer, then examine all Japanese references by meta-analysis on susceptible genes over the past 20 years, and discuss whether new candidates and changing trend in Japan could be caused by environmental change.

Optimization of a real-time PCR assay to quantitate airborne fungi collected on a gelatin filter.

The present study aimed to optimize a real-time PCR assay to quantitate airborne fungi collected on a gelatin filter. In particular, the study optimized conditions for the DNA extraction and real-time PCR amplification to accurately measure airborne fungal concentrations. First, time of fine bead homogenization to extract the DNA from fungal cells was optimized to maximize the DNA yield and prepare the DNA suitable for sensitive and precise quantification by a subsequent real-time PCR analysis. Second, a condition for the real-time PCR amplification was optimized to successfully amplify and quantitate the extracted fungal DNA. In particular, a dilution ratio of the DNA extracts to be introduced to PCR was optimized to achieve an appropriate balance between mitigating PCR inhibition and securing detection sensitivity. Since concentrations of airborne fungi generally observed in indoor and outdoor environments (i.e., 10(1)-10(4) CFU m(-3)) were found to be near the limit of quantification by the generally-used molecular-based detection technique in conjunction with use of gelatin filters, optimizations of these conditions were found to be crucial. Our preliminary result showed that a culture-based method underestimated concentrations of airborne environmental fungi by 1 to 2 orders of magnitude compared to those characterized by the real-time PCR assay.

Comparison of dry- and wet-based fine bead homogenizations to extract DNA from fungal spores.

The present study explored DNA extraction kinetics from fungal spores, i.e., Aspergillus niger, Penicillium chrysogenum and Cladosporium sphaerospermum, by fine bead mill homogenization. In particular, the study aimed to investigate basic differences between the dry- and wet-based methods. The results showed higher initial rates of the DNA extractions by the dry-based method than by the wet-based method, due to higher collision efficiency among fine beads and fungal spores. Based on the experimental results, we constructed kinetic models. While the results by the wet-based method were fitted well with an existing first-order release-degradation model, the results by the dry-based method were not fitted well. Meanwhile, a newly constructed first-order release-degradation model, assuming a proportion of the DNA remained inside the disrupted spore cells and protected from further sheer stress, showed good correlations. The real-time PCR assays showed the PCR efficiencies of the DNA obtained by the dry-based method were higher than those by the wet-based method likely due to increased moderate fragmentation of the DNA by the dry-based method. Thus, although wet-based methods have been commonly used, dry-based methods might also be applicable to achieve efficient extraction and PCR amplification of fungal DNA.

[Knowledge of guideline for asthma and a demand at the pharmacy--questionnaire based exploration].

BACKGROUND: To achieve a good control for asthma, cooperation of pharmacists is necessary. It is important to establish the system that the patients easily obtain advice about asthma from pharmacists and to spread the guideline. METHODS: For the first step, we explore the knowledge and usage of asthmatic guideline among pharmacists in the drug stores in this study. The questionnaires were distributed to 465 drug stores in the Seibu, minato-ku and bunnkyo-ku, Tokyo. RESULTS: The knowledge of guideline was 79% but the existence of guideline booklet at the pharmacy was 24%. The major demand at the pharmacy was to distribute pamphlet around 10 pages which contained treatment at the pregnancy and prevention of asthma. DISCUSSION: To spread usage of asthmatic guideline at the pharmacy, newly-devised plan is required.

Studies on a simultaneous analytical method of urinary nicotine and its metabolites, and their half-lives in urine.

The objectives of this research were to improve and standardize a relatively easy, highly sensitive and highly accurate method of measuring nicotine, cotinine and trans-3'-hydroxycotinine in the urine of non-smokers exposed to environmental tobacco smoke (ETS) and to clarify the reliability of this method. Blinded studies using this analytical method were conducted in two universities. Standard solutions of nicotine, cotinine and trans-3'-hydroxycotinine were prepared at one university, divided in two parts and sent to another two universities for analyses by gas chromatography-mass spectrometry (GC/MS) without revealing the concentrations. It was found that the assay lower limit was at a level that could be used in passive smoking surveys and good results were obtained in crosschecks of samples of unknown concentration between the two universities. Since this method was considered to be useful for analyzing these urinary substances, ETS exposure experiments were performed in three universities using urinary nicotine, cotinine and trans-3'-hydroxycotinine as specific biomarkers of the urine. Non-smokers were exposed to ETS in an exposure room in each university. It was found that the nicotine concentrations in the urine of the subjects exposed to ETS reached a peak at about 2 hours after the end of exposure, which was somewhat later than that in active smokers. Because cotinine and trans-3'-hydroxycotinine in the urine are metabolites of nicotine, it was evident that the quantities were lower and the increasing rates were also less than that of nicotine. When the deceases in nicotine/ creatinine, cotinine/creatinine and trans-3'-hydroxycotinine/creatinine ratios in the urine were calculated using theoretical curves, the half-life times were calculated to be 13.9, 20.0 and 63.0 hours, respectively.

Application of the personal aeroallergen sampler to assess personal exposures to Japanese cedar and cypress pollens.

We have recently developed the Personal Aeroallergen Sampler (PAAS), a passive sampler for aeroallergens. In the present study, the applicability of the PAAS for personal exposure assessments of cedar and cypress pollens was investigated by comparing with existing reference samplers. To investigate the usability of the PAAS as a personal sampler for the airborne pollens, it was compared with the Institute of Occupational Medicine (IOM) sampler, a traditionally used active personal sampler. Overall, the result showed a good correlation between the two methods, that is, R(2)=0.8082, suggesting the usability of the PAAS for the personal pollen samplings. The ratio of the pollen numbers collected by the PAAS to the IOM sampler was approximately 30%, which was consistent with our previous study investigating ambient dust particles. Meanwhile, the comparability of the PAAS to the Durham sampler, the most widely used stationary pollen trap, was also assured. Furthermore, we exemplified the seasonal peak of the personal pollen exposures was not necessarily reflected by the outdoor concentrations, indicating insufficiency of the stationary outdoor monitoring to represent the personal pollen exposures. The PAAS, a simple passive method, could be used in future field studies to elucidate the detailed mechanisms of allergic airway diseases such as cedar pollinosis.

[A study on preventive effects of mite allergens by specially-fabricated futons with anti-mite treatments].

BACKGROUND: The purpose of this study was to investigate effects of specially-fabricated futons (beds) with anti-mite treatments on reductions of mite allergens (Der p.1 and Der f.1) and serum IgE antibodies against Dp (Dermatophagoides pteronyssinus), Df (Dermatophagoides farinae) and house dust1. METHODS: The futons made by microfibers (Madoromi: M) and phenolic polymer grafted microfine fibers (Madoromi+ALLER BUSTER: M+A) were used. Three groups of student and nurse subjects were asked to use general woolen cotton futons, and the (M) and (M+A) futons for 11 months, respectively. RESULTS: After the 11 months, the ratios of Der p.1+f.1 allergens in the futons (M) and (M+A) to those in the control futon were 1/3.8 and 1/42.0, respectively, on average. The prevalence of serum IgE antibodies against Dp, Df and house dust1 was found to decrease from 46.7 to 6.7% for the group using the (M+A) futon. CONCLUSION: These results suggested the specially-fabricated futons with anti-mite treatments could effectively reduce mite allergens compared to those made from woolen cotton.

[A survey of subjective symptoms and life-style in junior high school students].

PURPOSE: A questionnaire survey was conducted to examine a relationship between indefinite complaints and life styles in junior high school students and to apply the results to life guidance. METHODS: Twenty nine public junior high schools were selected by random sampling of 13 cities and 3 towns in Kanagawa Prefecture. A self-reported questionnaire was supplied to all subjects, containing 100 life-style related items, including a simplified CMI (Cornel Medical Index) questionnaire. RESULTS: The number of students who were evaluated as "point medical examination" based on physical symptoms of CMI and "disorder" based on the mental and physical symptom increased with the grade for both males and females. The students who reported "the life rhythm was always irregular" tended to be in the group evaluated as "disorder" or "point medical examination". The life rhythm was related to bedtime, sleeping hours and eating habits. It was observed that the students whose daily habits were always irregular had late bedtime, short sleeping hours and an irregular eating habit. As a result of the quantification method for the second type of analysis, it was found that sleeping time was the most related factor to the life rhythm. Furthermore 90% and more of students reported they did not consider nutritional balance with regard to their eating habits. CONCLUSION: It was suggested that those students who had irregular life rhythm needed sufficient sleep and nutrition guidance to maintain their health.