Biomedical subjects

Toshiyuki Ohtani

Publications and source records attributed to Toshiyuki Ohtani.

14 recordsLinked to original sources

PubMed2007

Human brain structural change related to acute single exposure to sarin.

OBJECTIVE: This study aimed to identify persistent morphological changes subsequent to an acute single-time exposure to sarin, a highly poisonous organophosphate, and the neurobiological basis of long-lasting somatic and cognitive symptoms in victims exposed to sarin. METHODS: Thirty-eight victims of the 1995 Tokyo subway sarin attack, all of whom had been treated in an emergency department for sarin intoxication, and 76 matched healthy control subjects underwent T1-weighted and diffusion tensor magnetic resonance imaging (DTI) in 2000 to 2001. Serum cholinesterase (ChE) levels measured immediately and longitudinally after the exposure and the current severity of chronic reports in the victims were also evaluated. RESULTS: The voxel-based morphometry exhibited smaller than normal regional brain volumes in the insular cortex and neighboring white matter, as well as in the hippocampus in the victims. The reduced regional white matter volume correlated with decreased serum cholinesterase levels and with the severity of chronic somatic complaints related to interoceptive awareness. Voxel-based analysis of diffusion tensor magnetic resonance imaging further demonstrated an extensively lower than normal fractional anisotropy in the victims. All these findings were statistically significant (corrected p < 0.05). INTERPRETATION: Sarin intoxication might be associated with structural changes in specific regions of the human brain, including those surrounding the insular cortex, which might be related to elevated subjective awareness of internal bodily status in exposed individuals.

Adult↗

PubMed2006

No association between the Clara cell secretory protein (CC16) gene polymorphism and personality traits.

Clara cell secretory protein (CC16) is an anti-inflammatory protein expressed in the respiratory tract. Several studies have suggested the association between CC16 and mental disturbances, such as schizophrenia, depression, and post-traumatic stress disorder. In the present study, we investigated the association between the CC16 gene A38G polymorphism and personality traits in 214 healthy Japanese subjects. Personality traits were evaluated by using the Revised NEO Personality Inventory (NEO PI-R) and the State-Trait Anxiety Inventory (STAI). As a result, no significant association was observed between the genotypes and the scores of the NEO PI-R or the STAI. The present results suggest that CC16 may not have a major role in the development of personality traits.

Adult↗

PubMed2006

No association of 5-HT2C, 5-HT6, and tryptophan hydroxylase-1 gene polymorphisms with personality traits in the Japanese population.

Serotonin 2C receptor (5-HT(2C)), serotonin 6 receptor (5-HT(6)), and tryptophan hydroxylase-1 (TPH1) genes could be candidates for personality-related genes considering the role of serotonin in various mental functions and behavior. However, a limited number of studies have investigated the association between these genes and personality traits. In the present study, we investigated the three serotonin-related genes, 5-HT(2C), 5-HT(6), and TPH1 genes, in relation to personality traits in the Japanese population. The Cys23Ser polymorphisms in the 5-HT(2C) gene, the 267T/C polymorphism of the 5-HT(6) gene, and the 779A/C polymorphisms in the TPH1 gene were genotyped in 253 healthy Japanese subjects. Personality traits were evaluated by using the Revised NEO Personality Inventory (NEO PI-R) and the State-Trait Anxiety Inventory (STAI). As a result, no significant association was observed between the polymorphisms and the NEO PI-R or the STAI scores. The present results did not provide evidence for the association between the three serotonin-related genes and personality traits. The genes might not have major role in the development of personality traits, although further investigation with larger sample size may be recommended for conclusion.

Adult↗

PubMed2006

Voxel-based diffusion tensor analysis reveals aberrant anterior cingulum integrity in posttraumatic stress disorder due to terrorism.

Recent functional neuroimaging work has suggested that interregional functional connectivity between the anterior cingulate cortex (ACC), other limbic, and prefrontal regions may be involved in the pathophysiology of posttraumatic stress disorder (PTSD). However, less attention has been paid to the white matter network. Voxel-based analysis enables an exploration of morphological or functional changes throughout the entire brain. Here we undertook the first application of this technology to diffusion tensor data in patients with PTSD. Participants were 9 victims of the Tokyo subway sarin attack with PTSD and 16 matched victims of the same traumatic event without PTSD. The voxel-based analysis showed a significant fractional anisotropy increase in the left anterior cingulum, subjacent to the left ACC gray matter where we previously found a volume decrement, in PTSD subjects. Moreover, the severity was positively, but not significantly associated with the fractional anisotropy of the left anterior cingulum in the victims with PTSD, using the region of interest defined in the native space with the inverse normalization technique. The present study demonstrated further evidence of abnormalities of both the ACC, a structure that is pivotally involved in attention, emotional regulation, and fear conditioning, and of subjacent white matter in the pathology of PTSD.

Adult↗

PubMed2006

Association between dopamine D4 receptor (DRD4) exon III polymorphism and Neuroticism in the Japanese population.

The association between the dopamine D4 receptor (DRD4) exon III polymorphism and personality trait of novelty seeking (NS) has been studied intensively. In the Japanese population, the results of the previous studies did not always coincide. In the present study, we investigated the association between the polymorphism and personality traits evaluated by using the Revised NEO Personality Inventory (NEO PI-R) and State-Trait Anxiety Inventory (STAI) in 196 Japanese subjects. A meta-analysis of the present and previous Japanese studies was also conducted regarding NS. As a result, significant association was observed between the polymorphism and personality traits evaluated by using NEO PI-R as a whole (p=0.022, MANCOVA). Subsequent analyses showed a significant association between short alleles (2-4 repeats) and higher scores for Neuroticism or its subscales, Anxiety, Depression, and Vulnerability (p=0.015, 0.039, 0.021, and 0.008, respectively, uncorrected). No other significant difference in the scores for NEO PI-R was observed in the subsequent analyses. Significant association was also observed between the polymorphism and scores for STAI as a whole (p=0.004, MANCOVA). Subsequent analyses did not show significant association, although a weak trend for the relation between the genotype consisting of short alleles and Trait Anxiety was observed (p=0.10, uncorrected). The meta-analysis showed no significant association between the polymorphism and NS. Thus, the present study suggested the association between the short allele of the DRD4 exon III polymorphism and personality trait of Neuroticism in Japanese subjects.

Adult↗

PubMed2006

Sensitivity to seasonal changes in panic disorder patients.

It has been suggested that symptoms of panic disorder may be significantly affected by seasonal factors including weather changes, although few studies have explored the issue. The purpose of the present paper was to investigate clinical data to examine sensitivity of panic disorder patients to seasonal changes and seasonal fluctuation of panic disorder symptoms. A self-rating questionnaire consisting of the Seasonal Pattern Assessment Questionnaire (SPAQ) and additional self-rating questions were analyzed in 146 Japanese patients (50 male, 96 female) with panic disorder (DSM-IV) at an outpatient clinic for anxiety disorder. The average of the Global Seasonality Scores (GSS) was 12.5+/-4.7 and 25.3% of the patients were suggested to suffer from seasonal affective disorder, according to the GSS. Frequency of the panic attack was found to fluctuate seasonally, with peaks in August and December (P=0.005 and 0.01, chi2 test). The present results indicate that panic disorder patients may be more sensitive to seasonal and meteorological factors than the general population and become more fragile in a specific season or months. This might assist in the development of preventive measures for the frequent recurrence of symptoms in panic disorder.

Adult↗

PubMed2006

Association between corticotropin-releasing hormone receptor 2 (CRHR2) gene polymorphism and personality traits.

Corticotropin-releasing hormone (CRH) has been implicated in the pathophysiology of anxiety disorders and depression. Corticotropin-releasing hormone receptor 2 (CRHR2) is one of the receptors that mediate CRH signal. The purpose of the present study was to investigate the association between the CRHR2 gene and personality traits, evaluated using the Revised NEO Personality Inventory (NEO PI-R), in 243 healthy Japanese subjects. As a result, significant association was observed between the polymorphism in intron 2 (rs2267717) and Openness (P = 0.004, uncorrected, anova), while no relationship was observed concerning Neuroticism. The present result suggests an association between CRHR2 and the personality trait of Openness.

Adult↗

PubMed2006

Clinical features of soft bipolarity in major depressive inpatients.

Because of the difficulties of ascertaining episode of hypomania by past history of the patients, it is of clinical value to find variables which predict the development of bipolar II disorder in depressive patients. Taking advantage of relatively long hospitalization, the authors tried to elucidate fine clinical features of the soft bipolarity. The subjects were 39 patients with Major Depressive Episode, diagnosed according to the 4th edition of the Diagnostic and Statistical Manual criteria. Among them, 15 patients were diagnosed as bipolar II disorder (BPII), whereas 24 patients were with unipolar depression (UP), using a structured clinical interview to assess the mood spectrum (SCI-MOODS). In addition to ordinary clinical and demographic variables, the authors studied fine symptomatology of depression, premorbid personality, and interpersonal relationship. Continuous variables were analyzed by t-test. Categorical variables were tested by chi2 analysis. In terms of premorbid personality, manic type (Zerssen) was found more frequently in BPII (UP 2/24, BPII 9/15, P < 0.05). Patients with BPII tended to show apparently quick disappearance of depressive symptoms (UP 2/24, BPII 9/15, P = 0.01). The most prominent result was a high prevalence of comorbidity of borderline personality disorder (BPD) among BPII (UP 0/24, BPII 6/15, P = 0.02). As Akiskal indicated that mood lability represents the most powerful predictor of hypomanias, patients with BPII showed quick response in mood to admission. The current subjects with BPII had high frequency of manic type of premorbid personality, indicating the usefulness of this variable for the prediction of hypomanias. Finally, the authors could observe development of BPD during hospitalization exclusively among BPII, to support the possibility of BPD as a state effect of BPII.

Adolescent↗

PubMed2005

Hemodynamic response to emotional memory recall with eye movement.

Previous studies on rapid eye movement sleep have demonstrated the effect of eye movement on emotional memory. However, the brain mechanism involved in the influence of the eye movement on the emotional recall remains unclear. We investigated the prefrontal response during an emotional memory recall with and without eye movement. Ten healthy volunteers were recruited. The changes in concentration of oxygenated hemoglobin ([oxy-Hb]) in the prefrontal cortex were examined using near-infrared spectroscopy (NIRS) during a task that involved emotional recall with and without eye movement. Six participants demonstrated a significant increase in [oxy-Hb] during emotional recall, and the level of increase was reduced through repeated emotional recall with eye movement. The results suggest that eye movement is associated with a reduction in the hemodynamic response to emotional memory recall.

Adult↗

PubMed2004

Association between lower P300 amplitude and smaller anterior cingulate cortex volume in patients with posttraumatic stress disorder: a study of victims of Tokyo subway sarin attack.

Previous investigations of auditory P300 event-related potentials have provided electrophysiological evidence for attentional problems in patients with posttraumatic stress disorder (PTSD). The present study sought to evaluate the relationship between P300 deficits and underlying brain morphological abnormalities in never-treated, comorbidity-free patients with PTSD following the Tokyo subway sarin attack. Out of 47 victims recruited, 8 victims with PTSD and 13 victims without PTSD were identified. Correlational analyses were performed between auditory P300 amplitude at Pz electrode site elicited in an oddball task and anterior cingulate gray matter volume that was shown to be reduced in our previous study using voxel-based morphometry on magnetic resonance imaging. Victims with PTSD showed significantly lower amplitudes of P300 compared with victims without PTSD, and the lower P300 amplitudes at Pz were significantly associated with higher avoidance/numbing scores in the PTSD group. Furthermore, in the PTSD group only, the P300 amplitudes showed a trend toward significant positive correlation with voxel densities of the anterior cingulate cortex gray matter. These results provide the first evidence that electrophysiological deficits of controlled attention observed in patients with PTSD may be linked to underlying brain morphological abnormalities.

Adult↗

PubMed2004

Mitochondrial DNA polymorphisms and extraversion.

Mitochondria is the major site of energy production in cells, therefore, mitochondrial abnormality may affect functions of organs including the brain, which constantly requires high levels of energy consumption. Previous studies have suggested a role of mitochondria and their DNA polymorphisms in neuro-psychiatric disorders, including Alzheimer's disease, Parkinson's disease, schizophrenia and bipolar mood disorder. Thus, we hypothesized that mitochondrial DNA polymorphisms might be related with the development of personality. The present study investigated a role of two mitochondrial DNA polymorphisms, the C5178A and A10398G, in personality traits evaluated using the NEO PI-R scores in 238 healthy Japanese volunteers. Subjects with the 5178A genotype showed significantly higher extraversion score than those with the 5178C genotype (P = 0.027), while no significant association was observed between the C5178A polymorphism and other scores. No significant association was found between the A10398G polymorphism and any scores. Regarding the 5178-10398 haplotype, the score of extraversion, not other scores, was significantly associated with the A-G haplotype (P = 0.042). Although further studies are recommended for the confirmation, the result may suggest a role of the mitochondrial DNA polymorphism in the personality trait.

Adult↗

PubMed2004

Post-traumatic stress disorder symptoms in victims of Tokyo subway attack: a 5-year follow-up study.

Sarin gas was dispersed in a Tokyo subway in 1995. This study investigates the mental and somatic symptoms of the 34 victims 5 years after the attack. Structured interviews (Clinician-Administered Post-Traumatic Stress Disorder [CAPS] and Mini International Neuropsychiatric Interview) and self-rating questionnaires were used to assess the symptoms. Not only post-traumatic stress disorder (PTSD) but also non-specific mental symptoms persisted in the victims at a high rate. A total of 11 victims were diagnosed with current or lifetime PTSD according to CAPS. Victims with PTSD showed higher anxiety levels and more visual memory impairment. A significant correlation between the total score of Impact of Event Scale-Revised (IES-R) and CAPS was found, indicating that IES-R is a useful tool for evaluating PTSD.

Adult↗

PubMed2003

Hypoactivation of the prefrontal cortex during verbal fluency test in PTSD: a near-infrared spectroscopy study.

Several studies have suggested that there is frontal dysfunction in subjects with posttraumatic stress disorder (PTSD). We investigated the relationship between alterations of the hemodynamic response of the prefrontal cortex during a cognitive task (verbal fluency task; VFT) and memory function measured using the Wechsler Memory Scale-Revised (WMS-R). The subjects were victims of the Tokyo Subway Sarin attack with (n = 8) or without (n = 26) PTSD. Hemodynamic response in the prefrontal cortex was measured using a 24-channel near-infrared spectroscopy (NIRS) system. Subjects with PTSD had a significantly smaller response of oxygenated hemoglobin and total hemoglobin during the VFT compared with those without PTSD, although there was no significant difference in performance on the VFT. Subjects with PTSD had significantly lower scores on attention and concentration in the WMS-R, which was positively correlated with the increase of total hemoglobin during the VFT. The 'frontal dysfunction' observed in subjects with PTSD may be a secondary phenomenon to reduced attentional capacity.

Adult↗

PubMed2003

Activation of the prefrontal cortex to trauma-related stimuli measured by near-infrared spectroscopy in posttraumatic stress disorder due to terrorism.

To develop a noninvasive method for psychophysiological assessment of posttraumatic stress disorder (PTSD), 34 victims of the Tokyo Subway Sarin Attack in 1995 including 8 diagnosed as PTSD and 12 controls were examined by a multichannel near-infrared spectroscopy (NIRS) system. Hemodynamic response in the prefrontal cortex was monitored during the presentation of trauma-related and control stimuli by video images. Skin conductance response (SCR) was also examined. Oxygenated hemoglobin significantly increased during the trauma-related image in the victims with or without PTSD. Deoxygenated hemoglobin significantly decreased only in victims with PTSD. No significant alteration was found in controls. Significantly enhanced SCR was also observed in the victims with PTSD during trauma-related stimuli. The findings suggest that measurement of cerebral hemodynamic response by NIRS is useful for psychophysiological assessment of PTSD.

Adult↗