Pregnancy parturition scars in the preauricular area and the association with the total number of pregnancies and parturitions.

OBJECTIVES: The aim of the present study was to clarify the association between the degree of development of pregnancy parturition scars (PPSs) and the total number of pregnancies and parturitions (TNPPs) on the basis of new identification standards for PPS in the preauricular area. MATERIALS AND METHODS: Preauricular grooves were macroscopically observed on the pelves of 103 early modern males and 295 females (62 early modern females; 233 present-day females). Three categories of PPS in the preauricular area were defined. The association between the degree of development of PPS in the preauricular area and the TNPP was analyzed in 90 present-day females with detailed lifetime data. RESULTS: PPS could not estimate the exact TNPP. However, it was shown that no PPS indicated no TNPP, weak PPS indicated a lower TNPP, and developed PPS indicated a higher TNPP. DISCUSSION: Even though the possibility remains that some PPS indicate no TNPP, the results showed that the percentage of each PPS category indicated fertility in the population, suggesting that the strength of the association between the degree of development of PPS and the TNPP was affected by the classification system, the reliability of lifetime data, and the statistical methods used for analysis.

General psychological distress among Japan Self-Defense Forces personnel dispatched on United Nations peacekeeping operations and their spouses.

AIM: The importance of family care during international deployment is emphasized within military organizations, but mental health interactions between deployed personnel and their spouses have not yet been assessed. This study addressed this gap by examining couples' mental health throughout a deployment period. METHODS: The mental health of 324 spousal dyads of Japan Self-Defense Forces personnel dispatched for a half-year United Nations Disengagement Observer Force mission was examined, using longitudinal data derived from a survey at four time points: one-month pre-deployment, initial deployment, middle deployment, and immediately after homecoming. The 30-item General Health Questionnaire was used to evaluate general psychological distress, with high scores (≥7) indicating adverse mental health. RESULTS: The spouses' general psychological distress was significantly higher compared with the deployed personnel (P < 0.001). The high general psychological distress of personnel was significantly related to that of their spouses (odds ratio = 2.24; 95% confidence interval, 1.32-3.80), and vice versa (odds ratio = 2.38; 95% confidence interval 1.39-4.08). CONCLUSION: Mental health care will be beneficial for not only deployed personnel but also their spouses.

Differential effects of voluntary wheel running and toy rotation on the mRNA expression of neurotrophic factors and FKBP5 in a post-traumatic stress disorder rat model with the shuttle-box task.

Life-threatening experiences can result in the development of post-traumatic stress disorder. We have developed an animal model for post-traumatic stress disorder (PTSD) using a shuttle box in rats. In this paradigm, the rats were exposed to inescapable foot-shock stress (IS) in a shuttle box, and then an avoidance/escape task was performed in the same box 2 weeks after IS. A previous study using this paradigm revealed that environmental enrichment (EE) ameliorated avoidance/numbing-like behaviors, but not hyperarousal-like behaviors, and EE also elevated hippocampal brain-derived neurotrophic factor (BDNF) expression. However, the differential effects of EE components, i.e., running wheel (RW) or toy rotation, on PTSD-like behaviors has remained unclear. In this experiment, we demonstrated that RW, toy rotation, and EE (containing RW and toy rotation) ameliorated avoidance/numbing-like behaviors, induced learning of avoidance responses, and improved depressive-like behaviors in traumatized rats. The RW increased the hippocampal mRNA expression of neurotrophic factors, especially BDNF and glial-cell derived neurotrophic factor. Toy rotation influenced FK506 binding protein 5 mRNA expression, which is believed to be a regulator of the hypothalamic-pituitary-adrenal (HPA)-axis system, in the hippocampus and amygdala. This is the first report to elucidate the differential mechanistic effects of RW and toy rotation. The former appears to exert its effects via neurotrophic factors, while the latter exerts its effects via the HPA axis. Further studies will lead to a better understanding of the influence of environmental factors on PTSD.

The relationship between dispositional empathy, psychological distress, and posttraumatic stress responses among Japanese uniformed disaster workers: a cross-sectional study.

BACKGROUND: Disaster workers suffer from psychological distress not only through the direct experience of traumatic situations but also through the indirect process of aiding disaster victims. This distress, called secondary traumatic stress, is linked to dispositional empathy, which is the tendency for individuals to imagine and experience the feelings and experiences of others. However, the association between secondary traumatic stress and dispositional empathy remains understudied. METHODS: To examine the relationship between dispositional empathy and mental health among disaster workers, we collected data from 227 Japan Ground Self-Defense Force personnel who engaged in international disaster relief activities in the Philippines following Typhoon Yolanda in 2013. The Impact of Event Scale-Revised and the Kessler Psychological Distress Scale were used to evaluate posttraumatic stress responses (PTSR) and general psychological distress (GPD), respectively. Dispositional empathy was evaluated through the Interpersonal Reactivity Index, which consists of four subscales: Perspective Taking, Fantasy, Empathic Concern, and Personal Distress. Hierarchial linear regression analyses were performed to identify the variables related to PTSR and GPD. RESULTS: High PTSR was significantly associated with high Fantasy (identification tendency, ß = 0.21, p < .01), high Personal Distress (the self-oriented emotional disposition of empathy, ß = 0.18, p < .05), and no experience of disaster relief activities (ß = 0.15, p < .05). High GPD was associated with high Personal Distress (ß = 0.28, p < .001), marital status (married, ß = 0.22, p < .01), being female (ß = 0.18, p < .01), medical unit (ß = 0.18, p < .05), and no experience of disaster relief activities (ß = 0.13, p < .05). CONCLUSIONS: Among Japanese uniformed disaster workers, high PTSR was associated with two subtypes of dispositional empathy: the self-oriented emotional disposition of empathy and high identification tendency, whereas high GPD was associated with high identification tendency. Educational interventions that aim to mitigate these tendencies might be able to relieve the psychological distress of disaster workers.

The effects of living environment on disaster workers: a one-year longitudinal study.

BACKGROUND: Defense Force workers engaged in disaster relief activities might suffer from strong psychological stress due to the tasks that they had been involved. We evaluated how living environments, work environments, and individual factors psychologically affect those who engaged in disaster relief activities. METHOD: Data generated with 1506 personnel engaged in the Great East Japan Earthquake relief activity were analyzed. Those who scored ≥25 points on the Impact of Events Scale-Revised and the Kessler Psychological Distress Scale (K10) were allocated into the high post-traumatic stress response (high-PTSR) group, and the high general psychological distress (high-GPD) group, respectively. RESULTS: The multiple logistic regression analysis extracted living environment (camping within the shelter sites) as the significant risk factor for both high-PTSR (OR = 3.39, 95 % CI 2.04-5.64, p < 0.001) and high-GPD (OR = 3.35, 95 % CI 1.77-6.34, p < 0.001) groups. CONCLUSION: It is desirable for disaster workers to have a living environment in which they can keep an appropriate distance from the victims.

[Involvement of autophagy in neuronal plasticity by psychiatric treatment].

Recently we have reported increased hippocampal autophagy signaling after multiple electroconvulsive seizure treatments. The involvement of autophagy process in the neuronal plasticity of synapses and dendrites and in the regulation of the number of specific receptors has been reported in basic studies using C. elegans, drosophila, and cultured neurons. The importance of the autophagy process in neuronal plasticity that supports the stress resilience should be further studied.

Modeling and comparing the organization of circular genomes.

MOTIVATION: Most prokaryotic genomes are circular with a single chromosome (called circular genomes), which consist of bacteria and archaea. Orthologous genes (abbreviated as orthologs) are genes directly evolved from an ancestor gene, and can be traced through different species in evolution. Shared orthologs between bacterial genomes have been used to measure their genome evolution. Here, organization of circular genomes is analyzed via distributions of shared orthologs between genomes. However, these distributions are often asymmetric and bimodal; to date, there is no joint distribution to model such data. This motivated us to develop a family of bivariate distributions with generalized von Mises marginals (BGVM) and its statistical inference. RESULTS: A new measure based on circular grade correlation and the fraction of shared orthologs is proposed for association between circular genomes, and a visualization tool developed to depict genome structure similarity. The proposed procedures are applied to eight pairs of prokaryotes separated from domain down to species, and 13 mycoplasma bacteria that are mammalian pathogens belonging to the same genus. We close with remarks on further applications to many features of genomic organization, e.g. shared transcription factor binding sites, between any pair of circular genomes. Thus, the proposed procedures may be applied to identifying conserved chromosome backbones, among others, for genome construction in synthetic biology. AVAILABILITY: All codes of the BGVM procedures and 1000+ prokaryotic genomes are available at http://www.stat.sinica.edu.tw/∼gshieh/bgvm.htm.

Validity and reliability of the Secondary Traumatic Stress Scale-Japanese version.

AIM: This study assessed the validity and reliability of the Secondary Traumatic Stress Scale-Japanese Version. METHODS: The original Secondary Traumatic Stress Scale was translated into Japanese, and Japanese items were back-translated to English to confirm the accuracy of the translation. A total of 870 public health nurses from the Tohoku region in Japan completed the Secondary Traumatic Stress Scale-Japanese Version. An exploratory factor analysis was conducted to identify the number of components. Moreover, 351 public health nurses from the Saitama prefecture in Japan also completed the scale. A confirmatory factor analysis was performed with the factor structure identified in the exploratory factor analysis. RESULTS: The exploratory factor analysis identified two components: one associated with client-related distress and the other with trauma-related distress. The confirmatory factor analysis confirmed the two-factor structure. The two-factor structure model was better than the three-factor model presented in the original validation study for the English version of the scale. The two-factor model had good internal consistency for the overall product and the subscales. Pearson correlations showed that this model had good convergent validity against the Maslach Burnout Inventory, a psychological measure similar to the Secondary Traumatic Stress Scale. Finally, the two-factor model had good discriminant validity against the Maslach Burnout Inventory. CONCLUSION: This study identified two components of the Secondary Traumatic Stress Scale-Japanese Version that differ from the three components found in the original English version. The differences in the factor structure might indicate that the factor structure was culturally influenced.

Investigation of the impact of preconditioning with lipopolysaccharide on inflammation-induced gene expression in the brain and depression-like behavior in male mice.

Although several recent studies have suggested that neuroinflammation plays a role in depression, both medication and neuroinflammatory preventive strategies have been poorly investigated. Recent studies have indicated that preconditioning with lipopolysaccharide (LPS) reduces the damage that occurs following ischemic stroke and brain trauma. However, to date, the effects of LPS preconditioning on psychiatric symptoms have not been reported. Thus, we assessed gene expression and behavioral changes affected by preconditioning with low-dose (LD) LPS in male mice with systemic inflammation induced by administration of high-dose (HD) LPS. mRNA expression analyses of cytokine-, glial-, and oxidative stress-associated genes revealed that majority of these genes responded to HD LPS. Differential gene expression in the presence and absence of LD LPS preconditioning, identified a subset of genes that may contribute to the mechanism of LPS preconditioning in the brain. Notably, LPS preconditioning attenuated an increase in expression of the astrocyte marker Gfap caused by systemic inflammation, suggesting that astrocytes have a key role in endotoxin tolerance in the brain induced by LPS preconditioning. As increased astrocyte in the brain of patients with depression is suggested to contribute to the pathophysiology of major depression, LPS preconditioning might be applicable to the prevention and treatment of depression. Unfortunately, in this study, LPS preconditioning did not show a reversal effect on behavior decline due to high-dose LPS-induced systemic inflammation. Alternative aspects of behavioral changes should be assessed to identify behavioral components that are affected by LPS preconditioning. Nonetheless, the findings in the present study indicate the possibility of the mechanism of endotoxin tolerance induction in the brain via astrocyte regulation by LPS preconditioning. Since there has been reported pharmacological significance of astrocytes in psychiatric disorders, regulation of endotoxin tolerance might be a key method to control psychiatric symptoms.

Assessment of Factors Associated With Long-term Posttraumatic Stress Symptoms Among 56 388 First Responders After the 2011 Great East Japan Earthquake.

Importance: First responders are at risk for developing symptoms of posttraumatic stress disorder (PTSD). Little is known about the risk factors for developing PTSD during a years-long period after complex mass disasters. Objective: To explore the long-term course of PTSD symptoms and to identify risk factors and their relative association with PTSD among first responders dispatched to the 2011 Japanese earthquake, tsunami, and nuclear disaster. Design, Setting, and Participants: This 6-year, large, prospective cohort study was part of a continuous longitudinal study of Japan Ground Self-Defense Force first responders. The data were collected at 1, 6, 12, 24, 36, 48, 60, and 72 months after mission completion from 2011 to 2017. Of approximately 70 000 eligible participants, 56 388 were enrolled in this study. Data were analyzed from 2017 to 2020. Exposures: Stress exposures owing to personal or professional disaster experience (eg, duties with body recovery or radiation exposure risk) and working conditions (eg, deployment length, postdeployment overtime work). Main Outcomes and Measures: The Impact of Event Scale-Revised score assessed PTSD symptoms; scores of at least 25 were defined as probable PTSD. Cox proportional hazards regression models assessed the risk factors for incidence of probable PTSD. Results: Among the 56 388 participants, 97.1% were men, and the median age at enrollment was 34 (range, 18-63) years. A probable PTSD rate was 2.7% at 1 month and showed a downward trend in the first year and a subsequent plateau. The cumulative incidence of probable PTSD was 6.75%. The severity of PTSD symptoms demonstrated a high degree of rank-order stability over time. Rather than professional disaster experience, sociodemographic factors and working conditions were independently associated with the incidence of probable PTSD: personal experience of the disaster (hazard ratio [HR], 1.96; 95% CI, 1.72-2.24), deployment length of at least 3 months (HR vs <1 month, 1.75; 95% CI, 1.52-2.02), increased age (HR for ≥46 vs ≤25 years, 2.28; 95% CI, 1.79-2.92), and postdeployment overtime work of at least 3 months (HR vs little to none, 1.61; 95% CI, 1.39-1.87). Conclusions and Relevance: Given these findings, in the future, first responders' PTSD symptoms might be mitigated by shortening deployment length, avoiding postdeployment overtime work, and paying special attention to the needs of personnel with personal experience of the disaster or older age. Efforts to alleviate responders' initial symptoms will be required.

The effects of eicosapentaenoic acid dietary supplementation on behavioral parameters and expression of hippocampal brain-derived neurotrophic factor in an animal model of post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is a trauma- and stressor-related disorder, characterized by bi-directional symptomatic manifestations of increase in both hyperarousal/hypervigilance and numbing/avoidance. In our previous reports, we have proposed an animal model of PTSD using avoidance/escape task sessions in the shuttle box after delivering an inescapable foot-shock traumatization in the same box (Wakizono et al., 2007), and demonstrated the efficacy of 2-week administration of antidepressant on the hyperarousal/hypervigilant behavioral parameters (Sawamura et al., 2004) in the model. In this study, we observed a partial but significant efficacy of oral supplementation of eicosapentaenoic acid (EPA) for five weeks on the numbing/avoidance behavior in the experimental model. Additionally, western blot analyses using brain-derived neurotrophic factor (BDNF) monoclonal antibody revealed a decreased expression of BDNF protein, in the hippocampal region of the rats, due to foot-shock traumatization and a significantly increased expression of BDNF protein after oral EPA supplementation. The results indicate a possibility that alteration of the numbing/avoidance behavior parallels the expression of hippocampal BDNF in the rat brain. The present study suggests a possibility that EPA supplementation in the treatment of PTSD ameliorates persistent numbing/avoidance symptoms. (185 words).

Relationship between the subtypes of child abuse and affective temperaments: Comparison of depression and bipolar disorder patients and healthy controls using the reclassified Child Abuse and Trauma Scale.

BACKGROUND: We previously reported that child abuse indirectly predicts the diagnosis of major depressive disorder (MDD) or bipolar disorder (BP) based on higher scores of affective temperaments; however, the subtypes of child abuse have not been examined sufficiently. Therefore, in the present study, we used the reclassified version of the Child Abuse and Trauma Scale (CATS) to determine how the subtypes of child abuse affect affective temperaments. METHODS: A total of 502 participants (212 healthy controls, 163 patients with MDD and 127 patients with BP) were administered the Japanese version of the CATS; the Japanese version of the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire; and the Japanese version of the Patient Health Questionnaire-9. Data were analyzed by exploratory and confirmatory factor analyses, as well as by univariate and multivariate analyses. RESULTS: A five-factor structure was appropriate for the CATS. The MDD group scored significantly higher on all subtypes of the reclassified CATS than did the control group. Among the subscales of the reclassified CATS, physical abuse and loneliness/psychological stress were significant predictors of affective temperaments, although all subscales were significantly associated with affective temperaments compared to the original CATS. LIMITATIONS: Since child abuse was assessed retrospectively, there might be recall bias. Furthermore, as the study was limited to Japanese individuals, particularly those with mood disorders, the findings might not be generalizable. CONCLUSIONS: This study revealed that the subtypes of child abuse (especially physical abuse and loneliness/psychological stress) might be associated with MDD and BP.

Longitudinal Factors Associated With Increased Alcohol and Tobacco Use in Fukushima Nuclear Power Plant Workers 32 Months After the Nuclear Disaster: The Fukushima News Project Study.

OBJECTIVES: The aim of this study was to predict increased alcohol and tobacco use in Fukushima nuclear power plant (NPP) workers 3 years after a nuclear disaster. METHODS: Surveys were conducted in two postdisaster waves (Wave 1: 2 to 3 months; Wave 2: 32 months). Adjusted risk ratio (aRR) was computed to assess the covariates of increased alcohol and tobacco use in Wave 2. RESULTS: Increased alcohol use was associated with age of 29 years or less [aRR (95% confidence interval (95% CI): 1.26 (1.01 to 1.57)], major property loss [1.25 (95% CI 1.02 to 1.55)], and high posttraumatic stress responses (PTSRs) [1.34 (95% CI 1.08 to 1.67)] in Wave 1. Increased tobacco use was associated with age of 29 years or less [1.46 (95% CI 1.12 to 1.90)] and high PTSR [1.62 (95% CI 1.25 to 2.10)] in Wave 1 (P < 0.05). CONCLUSION: The workers' increased alcohol and tobacco use were predicted by major property loss (alcohol), age of 29 years or less, and high PTSR (alcohol/tobacco) in Wave 1.

Depression Promotes the Onset of Irritable Bowel Syndrome through Unique Dysbiosis in Rats.

Background/Aims: Although studies using conventional animal models have shown that specific stressors cause irritable bowel syndrome (IBS), it is unclear whether depression itself causes IBS. Our aim was to establish a rat model to determine if depression itself promotes the onset of IBS and to elucidate the role of gut microbiota in brain-gut axis pathogenesis during coincident depression and IBS. Methods: Rat models of depression were induced using our shuttle box method of learned helplessness. Visceral hypersensitivity was evaluated by colorectal distension (CRD) to diagnose IBS. Gut microbiota compositions were analyzed using high-throughput sequencing. In the subanalysis of rats without depression-like symptoms, rats with posttraumatic stress disorder (PTSD) were also examined. Results: The threshold value of CRD in depressed rats was significantly lower than that in control rats. Microbial community analysis of cecal microbiota showed that the relative abundance of Clostridiales incertae sedis, the most prevalent microbe, was significantly lower in depressed rats than in control rats. The distribution pattern of the microbiota clearly differed between depressed rats and control rats. Neither visceral hypersensitivity nor the composition of gut microbiota was altered in rats with PTSD-like phenotypes. Conclusions: Our rat model of depression is useful for clarifying the effect of depression on IBS and suggests that depression itself, rather than specific stressors, promotes the onset of IBS. Further, we provided evidence that various psychiatric diseases, viz., depression and PTSD, are associated with unique gut microbiota profiles, which could differentially affect the onset and progression of coincident IBS.

Relationship between post-traumatic stress disorder-like behavior and reduction of hippocampal 5-bromo-2'-deoxyuridine-positive cells after inescapable shock in rats.

AIM: Inescapable shocks (IS) have been reported to reduce the number of 5-bromo-2'-deoxyuridine (BrdU)-positive cells in hippocampus. Antidepressants prevent this reduction, and the role of neurogenesis in depression is now suggested. It has been reported, however, that the number of BrdU-positive cells was not different between the rats that developed learned helplessness and those that did not. This suggests that reduction of neurogenesis does not constitute a primary etiology of depression. It has been previously shown that IS can cause various post-traumatic stress disorder (PTSD)-like behavioral changes in rats. The aim of the present was therefore to examined whether the reduction of BrdU-positive cells relates to any PTSD-like behavioral changes in this paradigm. METHODS: Rats were given either inescapable foot-shocks (IS) or not shocked (non-S) treatment in a shuttle box on day 1 and received BrdU injections once daily during the first week after IS/non-S treatment. On day 14, rats treated with IS and non-S were given an avoidance/escape test in the shuttle box and dorsal hippocampal SGZ were analyzed by BrdU immunohistochemistry. RESULTS: In accordance with previously reported results, IS loading resulted in fewer BrdU-positive cells in the hippocampal subgranular zone (SGZ). Furthermore, in the IS-treated group, the number of BrdU-positive cells in the hippocampal SGZ was negatively correlated at a significant level with several hyperactive behavioral parameters but not with hypoactive behavioral parameters. Earlier findings had indicated that chronic selective serotonin re-uptake inhibitor administration, which is known to increase hippocampal neurogenesis, restored the increase in hypervigilant/hyperarousal behavior but did not attenuate the increase in numbing/avoidance behavior. CONCLUSION: The regulatory mechanism responsible for the decreased proliferation and survival of cells in the hippocampus may be related to the pathogenic processes of hypervigilance/hyperarousal behaviors.

Mental health in Japanese members of the United Nations peacekeeping contingent in the Golan Heights: effects of deployment and the Middle East situation.

This study evaluates the mental health of Japan Self-Defense Force (JSDF) members of the peacekeeping contingent in the Golan Heights before and since the Second Gulf War between 1998 and 2003. Before the war, the General Health Questionnaire 30 (GHQ30) scores during and after duty tended to be lower than those before duty; all scores were lower than those of adult Japanese men in general. After the war, GHQ30 scores did not significantly change between before, during, and after duty. Manifest Anxiety Scale (MAS) scores were not significantly different between groups. Stressors identified included problems with foreign language and familial matters at home. Post war stressors included work content and relationships with collaborating foreign army units. These findings suggest that the mental health of contingent members remained stable, with some variation in mental health conditions influenced by the situation in the Middle East. This study suggests that the stable mental condition of JSDF personnel during their deployment in the absence of combat, and that this could be enhanced by education about mental health issues and by providing counseling support to their families.

Construct validity and reliability of the Tachikawa Resilience Scale in the Japan Ground Self-Defense Force personnel.

PURPOSE: The importance of resilience as a mental health outcome has been reported in recent occupational health studies, although resilience is yet to be assessed in the Japan Ground Self-Defense Force (JGSDF) population. Our objective was to test whether the Tachikawa Resilience Scale (TRS), developed to measure the resilience of Japanese individuals, is useful for evaluating the resilience of the JGSDF. PATIENTS AND METHODS: We performed a cross-sectional study of 353 JGSDF peacekeeping personnel engaged in the United Nations Mission in the Republic of South Sudan from November 2015 to May 2016. We evaluated resilience using two psychological measures: the TRS and the Resilience Competence Scale - Japanese Short Version (RCS-JS). To verify the construct validity of the TRS, we performed exploratory factor analysis and confirmatory factor analysis. We subsequently conducted hierarchical multivariate regression analysis to evaluate the relationship of the TRS and the RCS-JS with psychological distress measured by the Japanese version of the Kessler Psychological Distress Scale. RESULTS: Of those recruited, 281 (79.6%) agreed to participate. The exploratory factor analysis revealed a one-factor model of the TRS. The confirmatory factor analysis model showed good fit (ratio of χ 2 to the degrees of freedom =1.409, P=0.105, comparative fit index =0.994, root mean square error of approximation =0.038). Both the TRS and the RCS-JS showed a significant inverse correlation with the Kessler Psychological Distress Scale, and the regression coefficient of the TRS was equivalent to that of the RCS-JS. CONCLUSION: We confirmed the construct validity and reliability of the TRS when applied to the JGSDF, and demonstrated the usefulness of the TRS in this population.

The Psychological Impact of the Great East Japan Earthquake on Japan Ground Self-Defense Force Personnel: A Three-Wave, One-Year Longitudinal Study.

OBJECTIVE: Approximately 70,000 Japan Ground Self-Defense Force (JGSDF) personnel were dispatched in the wake of the 2011 Great East Japan Earthquake and the tsunami and nuclear disaster that followed. This study was conducted to evaluate the mental health of the JGSDF personnel and the correlates. METHODS: Data collected from 56,753 participants at three time points (one, six, and 12 months after mission completion) were analyzed. Those who scored 25 or more points on the Impact of Events Scale-Revised (IES-R) and the Kessler Psychological Distress Scale (K10) were allocated into the high posttraumatic stress response (high-PTSR) group, and the high general psychological distress (high-GPD) group, respectively. RESULTS: The multiple logistic regression analysis identified the following factors as the significant risk factor related to high-PTSR or high-GPD status, with odds ratios of 2.0 or higher: deployment length of three or more months, being personally affected by the disaster, and being overworked continuously for three or more months after mission completion. No significant association was observed for duties with radiation exposure risk. CONCLUSIONS: Our findings suggest that disaster workers may be able to conduct disaster relief activities more safely with mission-related considerations of shorter deployment length and recognizing the effects on personnel personally affected by the disaster, in addition to avoiding overworking personnel after mission completion.

Stress and electroconvulsive seizure differentially alter GPR56 expression in the adult rat brain.

GPR56, a member of the G-protein-coupled receptor family, plays a role in the formation of the frontal and parietal brain lobes and cortical lamination in the embryonic stage. A recent report indicated the existence of GPR56 transcripts in the subventricular zone (SVZ) and hippocampal subgranular zone (SGZ) of the adult mouse brain. Both these regions are known to continually produce neural progenitor cells in the adult brain. Here, we demonstrate abundant GPR56 protein expression in the ependymal cell layer and SVZ as well as its reciprocal translational regulation by a 12-day behavioral stress paradigm and 10-day electroconvulsive seizure (ECS) treatment. Our study revealed that GPR56 transcript expression in the hippocampus was regulated by stress and seizure in a manner identical to that in the SVZ. GPR56 expression was downregulated by stress and upregulated by the ECS treatment in both regions, whereas nestin expression showed no changes. Western blot analysis revealed a robust ECS-induced increase in brain-derived neurotrophic factor expression in the wall of the lateral ventricle including the ependymal cell layer and the SVZ, which may provide a possible regulatory mechanism for GPR56 expression. We consider that GPR56 is expressed in the ependymal cell layer and in immature progenitor cells and that its expression is regulated by functional stimulation.

Stress vulnerabilities in an animal model of post-traumatic stress disorder.

We have studied the effects of inescapable electric foot shocks (ISs) on rats by using a subsequent avoidance/escape task performed in a shuttle box as an animal model of post-traumatic stress disorder (PTSD). In this study, the behavioral differences and the effects of chronic stress exposure prior to IS were examined among male rats of the Wistar, Fischer 344, and Lewis strains. In concordance with our previous report on the Wistar rats, we observed the characteristic features of PTSD in all three rat strains tested, that is, the hyperactive and hypoactive bidirectional behavioral changes that are associated with hypervigilant and hyperarousal behavior, and the numbing and avoidant behavior, respectively. The induction of hypoactive behaviors after IS was most exaggerated in the Fischer and Lewis strains. Although the count of hyperactive behaviors was maximal in the Fischer strain both at basal levels without IS and after IS, the increase in the rate of hyperactive behaviors by IS was the most prominent in the Lewis strain. In addition, preloaded chronic variable stress (CVS) enhanced the degree of hyperactive behavioral changes in the Wistar strain. Thus, we consider that the present study further validates the use of shuttle box paradigm as an animal model of PTSD by demonstrating the vulnerability due to genetic background and environmental preloaded stress.