Satoko Ezoe

Chromosome alterations in peripheral lymphocytes as indices of lifestyle and genotoxicity

SummaryShort-term cultures of human lymphocytes were used to investigate the in vitro metabolism of benzene and its genotoxicity, and to monitor genetic health effects of lifestyles. Metabolic (S9) activation of benzene and its metabolites, catechol, hydroquinone, and phenol, caused an increase in sister-chromatid exchanges (SCEs) with different optimal concentrations of S9 mix for converting each compound into further reactive forms. The data indicate that catechol and hydroquinone can be optimally metabolized to produce reactive species, presumably benzo(semi)quinones, under conditions of lower metabolic activity than those necessary for phenol and benzene. We have further investigated the correlations between chromosome alterations (SCEs, structural aberrations and micronuclei) in peripheral lymphocytes and individual lifestyles. Healthy lifestyles, or “good health practices” examined were 1) not smoking, 2) not drinking too much alcohol, 3) doing physical exercise regularly, 4) sleeping more than 6 h per night, 5) keeping nutritional balance in meals, 6) not snacking, 7) having breakfast everyday, and 8) not having too much perceived stress. The persons were categorized into 3 groups having good, moderate and poor lifestyles by the number of good health practices they do. Mean frequencies of chromosome alterations in lymphocytes from men with poor lifestyles have been shown to be significantly higher than those in cells from men having good lifestyles. Further experiments have been done to examine whether lymphocytes from men having unhealthy lifestyles might show a higher susceptibility 1) to the SCE production by treatment with hydroquinone, a major metabolite of benzene, and 2) to the chemicals inhibitory effect of repair of radiation-induced chromosome breakage, because our living and working environments contain possible repair inhibitors such as benzene, lead and chromium. The results showed that unhealthy lifestyles could make the cells to be more sensitive to the production of these chromosome alterations by the environmental and occupational agents.

Evaluation of autonomic nervous system by salivary alpha-amylase level and heart rate variability in patients with schizophrenia.

Several researches indicate that autonomic nervous system (ANS) dysfunction in patients with schizophrenia. Recently, salivary alpha-amylase (sAA) has been employed as a useful marker for ANS function. We investigated the extent of ANS dysfunction by measuring sAA and heart rate variability (HRV) of 25 patients with schizophrenia compared with controls. Schizophrenia group demonstrated a significant increase in sAA and markedly lower parasympathetic nervous system (PNS) activity in the HRV. However, there were no significant differences between two groups in sympathetic nervous system (SNS) activity. We concluded that PNS might be suppressed and the SNS shows relatively high activity in schizophrenia.

Yokukansan promotes hippocampal neurogenesis associated with the suppression of activated microglia in Gunn rat

BackgroundThe pathophysiology of schizophrenia (SCZ) remains unclear, and its treatment is far from ideal. We have previously reported that yokukansan (YKS), which is a traditional Japanese medicine, is effective as an adjunctive therapy for SCZ. However, the mechanisms underlying the action of YKS have not yet been completely elucidated. A recent meta-analysis study has shown that adjuvant anti-inflammatory drugs are effective for SCZ treatment, and it has been proposed that some of the cognitive deficits associated with inflammation may in part be related to inflammation-induced reductions in adult hippocampal neurogenesis. Although certain ingredients of YKS have potent anti-inflammatory activity, no study has determined if YKS has anti-inflammatory properties.MethodsUsing the Gunn rat, which has been reported as a possible animal model of SCZ, we investigated whether YKS affects cognitive dysfunction in an object-location test and the suppression of microglial activation and neurogenesis in the hippocampus.ResultsWe found that YKS ameliorated spatial working memory in the Gunn rats. Furthermore, YKS inhibited microglial activation and promoted neurogenesis in the hippocampal dentate gyrus of these rats. These results suggest that the ameliorative effects of YKS on cognitive deficits may be mediated in part by the suppression of the inflammatory activation of microglia.ConclusionsThese findings shed light on the possible mechanism underlying the efficacy of YKS in treating SCZ.

Chronotype and Smartphone Use among Japanese Medical Students

The authors investigated associations between smartphone use and chronotype. To 196 medical university students, they administered a set of self-reporting questionnaires designed to evaluate smartphone use and chronotype. Respondents were categorized into morning types and evening types: for females, the evening types scored higher for smartphone dependence; the authors also found greater duration of Web browsing service, in particular Twitter, in the evening types. No such correlation was found for male respondents. These findings provide evidence that, particularly for females, smartphone use and/or dependence may be related to chronotype.

Importance of measures to prevent suicides related to the Great East Japan Earthquake among women

THE GREAT EAST Japan Earthquake resulted in 15 887 dead and 2612 missing. The effects of the earthquake have become apparent in various forms and the rebuilding of lives in the affected areas is a painstaking endeavor. Care immediately after the earthquake has been important, and ongoing care is necessary. We researched the number of suicides in Japan from 2011 to 2013 as reported by the National Police Agency, the number of suicides related to the Great East Japan Earthquake from 2011 to 2013, and the motives for suicides as reported by the Cabinet Office. In addition, we calculated the male/female ratio of suicides, and here we discuss the characteristics of and trends in disaster-related suicides. The annual number of suicides in Japan during the 3 years ranged from 18 787 to 20 955 among men and from 8496 to 9696 among women. The male/female ratios in the number of suicides were 2.16 in 2011, 2.24 in 2012, and 2.21 in 2013. The numbers of suicides related to the Great East Japan Earthquake were 42 men and 13 women in 2011, 18 men and 6 women in 2012, and 23 men and 15 women in 2013. The male/female ratios were 3.23 in 2011, 3.00 in 2012, and 1.53 in 2013. The most common causative factors for suicide in 2011 were ‘health problems’, ‘economic and life problems’, and ‘unknown’ (20.8%). The most common causative factors for suicide in 2012 were ‘health problems’ (34.4%), followed by ‘family problems’, ‘economic and life problems’, and ‘unknown’ (15.6%), and the most common factors in 2013 were ‘health problems’ (41.5%) followed by ‘economic and life problems’ (17.0%). Based on these results, trends in suicides related to the Great East Japan Earthquake were compared to the overall suicidal trends in Japan. Men accounted for a large proportion of suicides in the year that the disaster occurred, but the proportion of suicides by women increased 2 years after the disaster. In the year that a disaster occurred, the main motives for related suicides were ‘health problems’ and ‘economic and life problems’. However the motive for suicide was increasingly ‘health problems’ after that. Significant changes in life and work, the effects of instability, and physical problems are major factors in suicides that occur soon after the disaster. After that, mental problems, such as post-traumatic stress disorder, become major causative factors for suicide. In summary, the mental state of women affected by a disaster should be followed up over a long period.

Analysis of oxidative stress expressed by urinary level of biopyrrins and 8-hydroxydeoxyguanosine in patients with chronic schizophrenia.

Previous studies have supported the claim that psychological stress induces the production of reactive oxygen species. Several authors have suggested that patients with psychiatric disorders show high levels of oxidative stress markers. We examined different oxidative stress markers in patients with chronic schizophrenia.

A Long-term Study of the Association between the Relative Poverty Rate and Suicide Rate in Japan

The annual number of suicides in Japan totaled around 23,000 in 1997 and abruptly increased to around 31,000 in 1998. This figure has remained high since then. This abrupt increase in the number of suicides was primarily due to an increase in suicides occasioned by economic concerns. The association between various economic factors and suicide must be studied in detail and over the long term in order to ascertain the association between economic concerns and suicide. This study examined the relative poverty rate and the suicide rate in Japan over 30 years and discussed the association between those two rates. The results suggest that the relative poverty rate may be associated with the suicide rate for both sexes. This association is true for men in particular. The organizations and professionals involved in implementing suicide prevention measures should be cognizant of the current findings and consider formulating additional specific measures.

Mobile Phone Use and Stress-Coping Strategies of Medical Students

This paper investigates associations between mobile phone use and stress coping. To 139 medical university students, a set of self-reporting questionnaires designed to evaluate mobile-phone use and stress coping was administered. In relation to the intensity of mobile phone use, the low-dependence group had statistically significantly higher scores for coping strategy, planful problem solving, than the high-dependence group. When the respondents were allocated to one of three groups according to which mobile-phone service they use most frequently, scores for planful problem solving were statistically significantly higher in the voice phone group than in the Web-browsing group. These findings suggest that the intensity and type of mobile phone use may be associated with stress coping, particularly planful problem solving strategy.

Effects of Psychological Stress from a National License Examination on the Urine 8-Hydroxy-Deoxyguanosine Levels in Young Female Students, Taking into Account the Menstrual Cycle

Objective: Urine 8-hydroxy-deoxyguanosine (U8-OHdG) was a marker of oxidative stress-induced DNA damage; it was increased by psychological stress. Since the menstrual cycle may confound or modify the association between psychological stress and U8-OHdG. The aim of this study was to verify the effect of psychological stress from a national license examination on levels of U8-OHdG, which is a biomarker of oxidative stress. And the effects of women’s menstrual cycles, which should be considered in mental and physical assessments, on U8-OHdG, were evaluated. Methods: The subjects were 18 female university students at a medical university in whom Self-rating Depression Scale (SDS) scores, State-Trait Anxiety Inventory (STAI) scores, and U8-OHdG levels were measured in 3 phases of the menstrual cycle, the follicular phase, ovulatory phase, and luteal phase. The mean values were taken for the group during a time of classroom learning. The same measurements were also made one week before and the day after a national license examination and the measurements were compared among the three periods. Results and Conclusion: State anxiety and U8-OHdG levels were significantly higher in those with a week before the national license examination than in those with classroom lecture (State anxiety: p = 0.002, U8-OHdG levels: p = 0.007). The menstrual cycle did not show a significant correlation with U8-OHdG levels. This study demonstrated that levels of the oxidative stress biomarker U8-OHdG are not affected by changes in the menstrual cycle. It also showed that U8-OHdG levels increased with the psychological stress of a national license examination.

Epidemiological Characteristics of Disaster-related Suicides in the34 Years since the Great East Japan Earthquake

The Great East Japan Earthquake struck Japan with a magnitude of 9.0 at 2:46 PM on March 11, 2011. Five years have passed since the earthquake and subsequent tsunami struck, but the mental and physical care of the victims, the livelihoods of those affected, and the economic impact of the disaster continue to cause social concern (Orui, Harada, & Hayashi, 2014; Tokuzu, Ouchi, Kikuchi & Konno, et al., 2015; Yabuki, Ouchi, Kikuchi & Konno, 2015; Hara, 2015). Over the past few years, research has examined the effects of the disaster on the cognitive function of the elderly (Ishiki et al., 2016), and one study suggested that oxidative stress may be associated with disaster-related hypertension (DRH) in individuals exhibiting effects of the Great East Japan Earthquake (Shiraishi et al., 2016).