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Dive into the research topics where Hirobumi Mashiko is active.

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Featured researches published by Hirobumi Mashiko.


Bulletin of The World Health Organization | 2015

Psychological distress and the perception of radiation risks: the Fukushima health management survey.

Yuriko Suzuki; Hirooki Yabe; Seiji Yasumura; Tetsuya Ohira; Shin-Ichi Niwa; Akira Ohtsuru; Hirobumi Mashiko; Masaharu Maeda; Masafumi Abe

Abstract Objective To assess relationships between the perception of radiation risks and psychological distress among evacuees from the Fukushima nuclear power plant disaster. Methods We analysed cross-sectional data from a survey of evacuees conducted in 2012. Psychological distress was classified as present or absent based on the K6 scale. Respondents recorded their views about the health risks of exposure to ionizing radiation, including immediate, delayed and genetic (inherited) health effects, on a four-point Likert scale. We examined associations between psychological distress and risk perception in logistic regression models. Age, gender, educational attainment, history of mental illness and the consequences of the disaster for employment and living conditions were potential confounders. Findings Out of the 180 604 people who received the questionnaire, we included 59 807 responses in our sample. There were 8717 respondents reporting psychological distress. Respondents who believed that radiation exposure was very likely to cause health effects were significantly more likely to be psychologically distressed than other respondents: odds ratio (OR) 1.64 (99.9% confidence interval, CI: 1.42–1.89) for immediate effects; OR: 1.48 (99.9% CI: 1.32–1.67) for delayed effects and OR: 2.17 (99.9% CI: 1.94–2.42) for genetic (inherited) effects. Similar results were obtained after controlling for individual characteristics and disaster-related stressors. Conclusion Among evacuees of the Fukushima nuclear disaster, concern about radiation risks was associated with psychological distress.


Psychiatry and Clinical Neurosciences | 1999

Effect of trazodone in a single dose before bedtime for sleep disorders accompanied by a depressive state: Dose‐finding study with no concomitant use of hypnotic agent

Hirobumi Mashiko; Shin-Ichi Niwa; Hisashi Kumashiro; Yoshihiro Kaneko; Satoru Suzuki; Yoshihiko Numata; Ryu Horikoshi; Yoshinori Watanabe

This was the first dose‐finding study of trazodone that was designed to be free of the concomitant use of hypnotics, in which the drug was administered in a single dose for sleep disorders combined with a depressive state. As a result, trazodone at the dosage of 50–100 mg/day improved sleep disorders, particularly at the 100 mg/day dosage. It was confirmed that trazodone improved sleep disorders combined with a depressive state when it was administered in a single dose before bedtime with no concomitant hypnotics.


PLOS ONE | 2014

Clinically significant behavior problems among young children 2 years after the Great East Japan Earthquake.

Takeo Fujiwara; Junko Yagi; Hiroaki Homma; Hirobumi Mashiko; Keizo Nagao; Makiko Okuyama

Background On March 11, 2011, a massive undersea earthquake and tsunami struck East Japan. Few studies have investigated the impact of exposure to a natural disaster on preschool children. We investigated the association of trauma experiences during the Great East Japan Earthquake on clinically significant behavior problems among preschool children 2 years after the earthquake. Method Participants were children who were exposed to the 2011 disaster at preschool age (affected area, n = 178; unaffected area, n = 82). Data were collected from September 2012 to June 2013 (around 2 years after the earthquake), thus participants were aged 5 to 8 years when assessed. Severe trauma exposures related to the earthquake (e.g., loss of family members) were assessed by interview, and trauma events in the physical environment related to the earthquake (e.g. housing damage), and other trauma exposure before the earthquake, were assessed by questionnaire. Behavior problems were assessed by caregivers using the Child Behavior Checklist (CBCL), which encompasses internalizing, externalizing, and total problems. Children who exceeded clinical cut-off of the CBCL were defined as having clinically significant behavior problems. Results Rates of internalizing, externalizing, and total problems in the affected area were 27.7%, 21.2%, and 25.9%, respectively. The rate ratio suggests that children who lost distant relatives or friends were 2.36 times more likely to have internalizing behavior problems (47.6% vs. 20.2%, 95% CI: 1.10–5.07). Other trauma experiences before the earthquake also showed significant positive association with internalizing, externalizing, and total behavior problems, which were not observed in the unaffected area. Conclusions One in four children still had behavior problems even 2 years after the Great East Japan Earthquake. Children who had other trauma experiences before the earthquake were more likely to have behavior problems. These data will be useful for developing future interventions in child mental health after a natural disaster.


British Journal of Sports Medicine | 2008

Superior performance in WAIS-R block design among top-level rugby players

Satoshi Kasahara; Hirobumi Mashiko; Shin-Ichi Niwa

Objective and design: Following a report that a well-known soccer player achieved a perfect score on the Block Design subtest of WAIS-R, WAIS-R was conducted on 31 skilled rugby players. Participants: Twenty-seven of the 31 players were recruited for further analyses. Results: In 14 of 27 players, Block Design scores were the highest of the 11 subtests. In addition to Block Design scores that exceeded the scores for the other subtests, the players’ Block Design scores were also better than scores for the standard sample. Conclusions: The Block Design is related to spatial cognitive ability. These results showed that highly skilled players of field and ball games possess high spatial cognitive abilities.


Journal of Clinical Psychopharmacology | 2012

Effects of aripiprazole and the Taq1A polymorphism in the dopamine D2 receptor gene on the clinical response and plasma monoamine metabolites level during the acute phase of schizophrenia.

Itaru Miura; Satoshi Takeuchi; Akihiko Katsumi; Azuma Mori; Keiko Kanno; Qiaohui Yang; Hirobumi Mashiko; Yoshihiko Numata; Shin-Ichi Niwa

Abstract The Taq1A polymorphism in the dopamine D2 receptor (DRD2) gene could be related to the response to antipsychotics. We examined the effects of the Taq1A polymorphism on the plasma monoamine metabolites during the treatment of schizophrenia with aripiprazole, a DRD2 partial agonist. Thirty Japanese patients with schizophrenia were treated with aripiprazole for 6 weeks. We measured plasma levels of homovanillic acid (pHVA) and 3-methoxy-4hydroxyphenylglycol (pMHPG) before and after treatment. The Taq1A polymorphism was genotyped with polymerase chain reaction. Aripiprazole improved the acute symptoms of schizophrenia and decreased pHVA in responders (P = 0.023) but not in nonresponders (P = 0.28). Although A1 allele carriers showed a tendency to respond to aripiprazole (61.5%) compared to A1 allele noncarriers (29.4%) (P = 0.078), there was not statistically significant difference in the response between the 2 genotype groups. There were significant effect for response (P = 0.013) and genotype × response interaction (P = 0.043) on the change of pHVA. The changes of pHVA differ between responders and nonresponders in A1 allele carriers but not in A1 allele noncarriers. There were no genotype or response effects or genotype × response interaction on the changes of the plasma levels of 3-methoxy-4hydroxyphenylglycol. Our preliminary results suggest that Taq1A polymorphism may be partly associated with changes in pHVA during acute schizophrenia.


Progress in Neuro-psychopharmacology & Biological Psychiatry | 2007

Sodium valproate at therapeutic concentrations changes Ca2+response accompanied with its weak inhibition of protein kinase C in human astrocytoma cells

Masatake Kurita; Satoshi Nishino; Kouji Ohtomo; Mayumi Rai; Hisayoshi Shirakawa; Hirobumi Mashiko; Shin-Ichi Niwa; Norimichi Nakahata

Sodium valproate (VPA) has been used clinically for treatment of not only epilepsy but also mood disorder. Although VPA is effective for treatment of epilepsy via inhibition of gamma-aminobutyric acid transaminase, it remains unknown why VPA is effective for the treatment of mood disorder. The authors examined the effect of VPA at therapeutic concentrations (300 and 600 microM) on the elevation of intracellular free calcium concentration ([Ca(2+)](i)) induced by carbachol, a muscarinic receptor agonist, in 1321N1 human astrocytoma cells. Treatment of the cells with 300 and 600 microM VPA for 2 min did not change the carbachol-induced [Ca(2+)](i) elevation. Treatment with 300 and 600 microM VPA for 48 h, however, reduced the elevation. Since we have shown that Li(+) reduced carbachol-induced [Ca(2+)](i) elevation in protein kinase C (PKC)-downregulated 1321N1 cells [Kurita, M., Mashiko, H., Rai, M., Kumasaka, T., Kouno, S., Niwa, S., Nakahata, N., 2002. Lithium chloride at a therapeutic concentration reduces Ca(2+)response in protein kinase C down-regulated human astrocytoma cells, Eur. J. Pharmacol. 442, 17-22.], the activity of PKC was examined. Treatment with VPA at the same concentrations for 24 or 48 h weakly reduced protein kinase C activity in membrane and cytosol fractions from the cells. On the other hand, the treatment of the cells with 600 microM VPA for 24 or 48 h slightly increased the B(max) value, but not the K(d) value, in the binding of [(3)H]quinuclidinyl benzylate, a muscarinic receptor ligand, to the membranes, suggesting that the number or affinity of muscarinic receptor did not decrease after VPA treatment. These results indicate that VPA at therapeutic concentrations slightly decreases the PKC activity and inhibits muscarinic receptor-mediated [Ca(2+)](i) elevation probably through change in the intracellular signaling pathway. VPA-induced reduction of PKC activity and [Ca(2+)](i) elevation may play a role in the treatment of mood disorder.


PLOS ONE | 2016

Severe Psychological Distress of Evacuees in Evacuation Zone Caused by the Fukushima Daiichi Nuclear Power Plant Accident: The Fukushima Health Management Survey

Yasuto Kunii; Yuriko Suzuki; Tetsuya Shiga; Hirooki Yabe; Seiji Yasumura; Masaharu Maeda; Shin-Ichi Niwa; Akira Otsuru; Hirobumi Mashiko; Masafumi Abe

Background Following the Great East Japan Earthquake on March 11, 2011, the nuclear disaster at the Fukushima Daiichi Nuclear Power Plant has continued to affect the mental health status of residents in the evacuation zone. To examine the mental health status of evacuee after the nuclear accident, we conducted the Mental Health and Lifestyle Survey as part of the ongoing Fukushima Health Management Survey. Methods We measured mental health status using the Kessler 6-item psychological distress scale (K6) in a total of 73,569 (response rate: 40.7%) evacuees aged 15 and over who lived in the evacuation zone in Fukushima Prefecture. We then dichotomized responders using a 12/13 cutoff on the K6, and compared the proportion of K6 scores ≥13 and ≤12 in each risk factor including demographic information, socioeconomic variables, and disaster-related variables. We also performed bivariate analyses between mental health status and possible risk factors using the chi-square test. Furthermore, we performed multivariate regression analysis using modified Poisson regression models. Results The median K6 score was 5 (interquartile range: 1–10). The number of psychological distress was 8,717 (14.6%). We found that significant differences in the prevalence of psychological distress by almost all survey items, including disaster-related risk factors, most of which were also associated with increased Prevalence ratios (PRs). Additionally, we found that psychological distress in each evacuation zone was significantly positively associated with the radiation levels in their environment (r = 0.768, p = 0.002). Conclusion The earthquake, tsunami and subsequent nuclear accident likely caused severe psychological distress among residents in the evacuation zone in Fukushima Prefecture. The close association between psychological distress and the radiation levels shows that the nuclear accident seriously influenced the mental health of the residents, which might be exacerbated by increased risk perception. To provide prompt and appropriate support, continued psychosocial intervention for evacuees is strongly recommended.


Neuropsychobiology | 1992

Platelet Alpha-2 Adrenergic Receptor Binding and Plasma Free 3-Methoxy-4-hydroxyphenyl-ethylene Glycol in Depressed Patients before and after Treatment with Mianserin

Motohisa Kaneko; Tomoyuki Kanno; Kyoichi Honda; Hirobumi Mashiko; Nobuyoshi Oosuga; Atsushi Watanabe; Hisashi Kumashiro

To examine the noradrenergic function in endogenous depression, binding of a selective agonist radioligand, 3H-UK14304, to platelet alpha 2-adrenergic receptors and plasma free 3-methoxy-4-hydroxyphenylethylene glycol (MHPG) were measured in untreated depressed patients. The effects of an antidepressant, mianserin, on these parameters were also assessed. The Bmax and Kd values for 3H-UK14304 binding in 26 untreated depressed patients were significantly higher (p less than 0.05, p less than 0.01) than those in 26 normal controls. On the other hand, there were no significant differences in plasma free MHPG levels between 12 untreated depressed patients and 12 normal controls. Chronic administration of mianserin to 8 depressed patients slightly increased the Bmax and Kd values. However, plasma free MHPG levels did not change after treatment. These findings suggest that depression is related to the subsensitivity of alpha 2-receptors as indicated by a decreased affinity of platelet alpha 2-receptors. In addition, chronic administration of mianserin further decreased the affinity of alpha 2-receptors. This suggests that mianserin acts not only on alpha 2-receptors but also on the other neurotransmitter systems.


Fukushima journal of medical science | 2014

MENTAL HEALTH OF CHILDREN

Hirobumi Mashiko

We describe the findings on the current state and challenges of pediatric psychiatry in Fukushima prefecture following the Great East Japan Earthquake. When examining the time elapsed after the earthquake, there is an impression that psychiatric problems become apparent in the early period after the earthquake in mothers who had demonstrated vulnerability in development and nurturing before the earthquake. However, at the current time more than three years since the earthquake, we are under the impression that psychiatric and behavioral symptoms are observed even in infants who had been on a good course for development and nurturing and had a high degree of satisfaction before the earthquake. A continuous long-term study is necessary in the future to further investigate this issue.


Psychiatry and Clinical Neurosciences | 1996

Trazodone for aggression in an adolescent with hydrocephalus

Hirobumi Mashiko; Hidekatsu Yokoyama; Hideo Matsumoto; Shin-Ichi Niwa

Abstract A case of 19 year old male with hydrocephalus is reported whose aggressive self‐injurious behaviors were resistant to conventional pharmacotherapy but successfully treated by trazodone. In addition to the self‐injurious behaviors, this patient displayed withdrawal and eating refusal, which initially resulted in his admission to a psychiatric ward. Various conventional treatments with pharmacotherapy (e.g., tricyclic antidepressants, antipsychotics, anxiolytics and anticonvulsants) in combination with psychotherapy and family therapy proved not to be effective for 15 months. Neither was electroconvulsive therapy successful. Administration of trazodone for 5 months after tapering of the above agents improved his aggressive behaviors. A survey of previous cases with organic brain syndromes who had aggressive behaviors and responded well to trazodone revealed that most of the cases were aged individuals and that cases in adolescence are rare.

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Hirooki Yabe

Fukushima Medical University

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Itaru Miura

Fukushima Medical University

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Yasuto Kunii

Fukushima Medical University

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Keiko Kanno-Nozaki

Fukushima Medical University

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Seiji Yasumura

Fukushima Medical University

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Shuntaro Itagaki

Fukushima Medical University

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Masaharu Maeda

Fukushima Medical University

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