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Dive into the research topics where Kazuhiro Kodama is active.

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Featured researches published by Kazuhiro Kodama.


Neuroscience Letters | 1999

Study of the association between the serotonin transporter gene regulatory region polymorphism and personality traits in a Japanese population

Chikara Kumakiri; Kazuhiro Kodama; Eiji Shimizu; Naoto Yamanouchi; Shin-ichi Okada; Shingo Noda; Hideki Okamoto; Toshio Sato; Hiroshi Shirasawa

Recently a relationship between serotonin transporter transcriptional control region (5-HTTLPR) polymorphism and anxiety related personality traits in Caucasians was reported. We performed PCR of DNAs from the blood for determining the 5-HTTLPR genotypes of 191 Japanese subjects, which were medical staff and students, and obtained Revised NEO Personality Inventory (NEO-PI-R) and the Temperament and Character Inventory (TCI) in 144 subjects. The association was analyzed by one-way ANOVA. The present study demonstrated that allelic frequency of 5-HTTLPR (s allele frequency was 0.785) in our subjects was considerably different from that in Caucasians. No significant differences were found in the anxiety-related personality traits among genotypes, while cooperativeness in TCI showed a significant difference among genotypes. The property of 5-HTTLPR may not be reflected directory on the personality inventories.


European Neurology | 1999

Decreased Regional Cerebral Metabolic Rate for Glucose in Systemic Lupus erythematosus Patients with Psychiatric Symptoms

Naoya Komatsu; Kazuhiro Kodama; Naoto Yamanouchi; Shin-ichi Okada; Shingo Noda; Yasushi Nawata; Katsuhiko Takabayashi; Itsuo Iwamoto; Yasushi Saito; Yoshitaka Uchida; Hisashi Ito; Kyosan Yoshikawa; Toshio Sato

To determine brain functional abnormality in systemic lupus erythematosus (SLE) patients with psychiatric symptoms, we evaluated 12 active SLE patients with or without psychiatric symptoms by means of [18F]2-fluoro-2-deoxy-D-glucose positron emission tomography (PET), magnetic resonance imaging and neuropsychological testing. Patients with psychiatric symptoms showed significantly poorer performance in tests which subserved attentional function. The PET study revealed that the psychiatric patients had significantly decreased regional cerebral metabolic rates for glucose in the prefrontal, inferior parietal and anterior cingulate regions. Prefrontal, inferior parietal and anterior cingulate dysfunction may be related to attentional deficits that are involved in various psychiatric symptoms in SLE. PET is an invaluable tool to reveal such brain functional abnormality seen in SLE patients with psychiatric symptoms.


Acta Neurologica Scandinavica | 2009

Effects of MRI abnormalities on WAIS-R performance in solvent abusers.

Naoto Yamanouchi; Shin-ichi Okada; Kazuhiro Kodama; Tadashi Sakamoto; H. Sekine; S. Hirai; Atsuhiro Murakami; Naoya Komatsu; Toshio Sato

Objective ‐ To clarify how chronic solvent abuse affects cognitive function using magnetic resonance imaging as an index of brain damage. Material and methods ‐ A total of 25 chronic solvent abusers underwent magnetic resonance imaging with quantitative neurometry and Wechsler Adult Intelligence Scales revised. Results ‐ The abusers with white matter change (n=10) showed significantly (P < 0.05) lower performance IQ, especially in Digit Symbol subtest (P<0.01). Also, the severity of pontine atrophy was significantly correlated with PIQ (r=0.60, P<0.01). Conclusions ‐ These data indicate that solvent abuse causes the decline in the test performance reflecting cognitive and fine motor dysfunction and that white matter changes and pontine atrophy may have some roles in this decline.


Psychiatry and Clinical Neurosciences | 1999

Regional cerebral blood flow abnormalities in chronic solvent abusers.

Shin-ichi Okada; Naoto Yamanouchi; Kazuhiro Kodama; Yoshitaka Uchida; Shinji Hirai; Tadashi Sakamoto; Shingo Noda; Naoya Komatsu; Toshio Sato

This study aimed to reveal regional abnormalities of cerebral blood flow (CBF) and their relation to amotivational syndrome which causes poor social prognosis in solvent abusers. Sixteen chronic solvent abusers (12 males and four females) along with five normal subjects underwent single photon emission computed tomography with N‐isopropyl‐p[123I]iodoamphetamine. The patients received a clinical evaluation with the Scale for the Assessment of Negative Symptoms. Using a semiquantitative method (normalized by the parietal cortex count), patients showed a statistically significant decrease in regional cerebral blood flow (rCBF) in the bilateral prefrontal cortices (P < 0.01). In addition, the severity of hypoperfusion in the bilateral prefrontal cortices was related to the degree of severity of the avolition–apathy scale on SANS (left; P < 0.05, right; P < 0.01) even after excluding the effect of antipsychotics. These results suggest that rCBF abnormalities, especially in the prefrontal cortex, develop in chronic solvent abusers, and that this frontal hypoperfusion may be a biological basis of amotivational syndrome.


Journal of the Neurological Sciences | 2000

Familial frontotemporal dementia with a P301L tau mutation in Japan

Kazuhiro Kodama; Shin-ichi Okada; Eizo Iseki; Anna Kowalska; Takeshi Tabira; Naohito Hosoi; Naoto Yamanouchi; Shingo Noda; Naoya Komatsu; Michiko Nakazato; Chikara Kumakiri; Mitsuyasu Yazaki; Toshio Sato

We have reported the family line with frontotemporal dementia (FTD) in Japan. This family line has so far included four patients. Patient II-1 (man) had a 10 year history of slowly progressive personality and behavioral changes and died at the age of 56. His neuropathological examination showed severe atrophy of the bilateral frontal and temporal cortices with neuronal loss, gliosis and superficial spongiosis. Pick bodies were not found. The neuropathological diagnosis was atypical Picks disease without Pick bodies or Pick-type in FTD. Patient III-2 is patient II-1s oldest daughter and was taken ill with personality change at the age of 52. She died at the age of 68. Patient III-4 is patient II-1s second daughter. Her onset with strange speech and behavior was at the age of 59. Patient III-5 is patient II-1s oldest son. He also had onset with personality change at the age of 54 and had the P301L mutation in tau. In all III generation cases CT/MRI revealed circumscribed frontotemporal atrophy. Patient III-5s PET/SPECT showed signs of hypoperfusion or hypometabolism in the bilateral frontotemporal areas. This is the first report of familial FTD with the P301L mutation in Japan.


Diabetes Research and Clinical Practice | 2000

Psychiatric disorders in juvenile patients with insulin-dependent diabetes mellitus

Michiko Nakazato; Kazuhiro Kodama; Shigeki Miyamoto; Mari Sato; Toshio Sato

The relationships of psychiatric characteristics to metabolic control and psychosocial functioning were examined in a group of 16 patients with insulin-dependent diabetes mellitus (IDDM) (mean age: 14.3+/-5.1 years, mean duration of follow-up: 5.0+/-2.3 years) and psychiatric disorders. The comparison is also made to 69 IDDM controls (mean age: 17.0+/-6.7 years) without psychiatric disorders. Metabolic control was evaluated in terms of glycosylated hemoglobin (HbA1c). Psychosocial functioning at both psychiatric treatment entry and discharge was assessed using the global assessment of functioning (GAF) scale. Subjects were divided into three subgroups - Somatoform Type (25%), Behavioral Type (50%) or Psychotic Type (25%) - according to the Diagnostic and Statistical Manual of Mental Disorders, third edition revised (DSM-III-R), based on semi-structured interviews. Four patients (25%) were diagnosed as having schizophrenia or schizoaffective disorder (Psychotic Type), which is rather rare. The mean HbA1c level in the Behavioral Type patients was significantly higher than in the other subgroups (P<0. 01). After psychiatric treatment a significant difference (P<0.0001) in the GAF Scale was observed in the Psychotic Type compared with the other subgroups. We conclude that the Behavioral Type is associated with poor metabolic control and that for the Psychotic Type, improved psychosocial functioning can be achieved through psychiatric treatment.


Comprehensive Psychiatry | 1999

Predictors of 1-Year Outcome for Patients With Panic Disorder

Naoyuki Shinoda; Kazuhiro Kodama; Tadashi Sakamoto; Naoto Yamanouchi; Tooru Takahashi; Shin-ichi Okada; Shingo Noda; Naoya Komatsu; Toshio Sato

The course of panic disorder (PD) is often prolonged, but factors that affect the social outcome have not yet been made clear. The aim of this study was to find predictors of outcome for patients with PD. The subjects were 65 outpatients (28 men and 37 women) with PD (DSM-III-R) who were treated at our hospital for more than 1 year. The factors affecting 1-year outcome were evaluated by multiple regression analysis. We found that the following were predictors of poor social outcome in PD: (1) severe agoraphobia at the first psychiatric examination and (2) long duration of illness before the first psychiatric consultation. Furthermore, the complication of hypochondriacal symptoms predicted a poor outcome for PD. Early attention to agoraphobia and hypochondriasis is essential for the treatment of PD, and early introduction to psychiatric treatment is recommended.


Psychiatry and Clinical Neurosciences | 1998

Activation of non‐primary motor areas during a complex finger movement task revealed by functional magnetic resonance imaging

Toshihiro Moriyama; Naoto Yamanouchi; Kazuhiro Kodama; Atsuhiro Murakami; Shin-ichi Okada; Shingo Noda; Naoya Komatsu; Toshio Sato; Tadahumi Kusaka; Kouichi Kato

We examined the brain activation induced by a complex finger movement task using functional magnetic resonance imaging (fMRI) with echo planar imaging (EPI). Imaging planes were set up for the observation of non‐primary motor areas. Among five normal males examined, four subjects naive to the task showed activations in contralateral primary and supplementary motor areas and the ipsilateral superior anterior part of the cerebellar hemisphere. Also, the bilateral premotor areas and the contralateral ventrolateral nucleus of thalamus were occasionally activated. No changes were observed in the putamen and globus pallidus. The subject accustomed to the task showed activation in the narrow areas of the contralateral primary motor and supplementary motor and premotor areas but not in the cerebellum. These results suggest that fMRI has nearly the same degree of detectability to that of positron emission tomography (PET) in regard to motor functions.


Psychiatry and Clinical Neurosciences | 1998

Depressive disorders as psychiatric complications after obesity surgery

Kazuhiro Kodama; Shingo Noda; Atsuhiro Murakami; Yukari Azuma; Naoki Takeda; Naoto Yamanouchi; Shin-ichi Okada; Naoya Komatsu; Toshio Sato; Yukimasa Miyazawa; Isao Kawamura

Three case reports of morbidly obese patients (two women and a man) who underwent vertical banded gastroplasty and who subsequently fell into depression, are presented here. The psychiatric diagnosis according to DSM‐III‐R (Diagnostic and Statistical Manual of Mental Disorders, 3rd edition, revised), the eating pattern before obesity surgery, the past history of mental disorder, social adaptation before surgery, psychological gain from their obese state, and the presence of unrealistic expectations of obesity surgery were investigated. Case 1 was diagnosed postoperatively as having a major depressive episode without a personality disorder. Case 2 was diagnosed postoperatively as having a major depressive episode. Case 3 had a depressive disorder not otherwise specified. Cases 2 and 3 had a social phobia with comorbidity of personality disorders. Binge eating disorder was confirmed in all patients before obesity surgery. There were differences between case 1 and cases 2 and 3 based on the presence of personality disorder and the time of onset of depression. When some psychiatric characteristics are confirmed in obese patients, obesity surgery should be undertaken more prudently because the patients may manifest depression postoperatively. The pre‐operative psychiatric assessment is essential for a decision on indication of obesity surgery.


Addiction Biology | 1998

Central nervous system impairment caused by chronic solvent abuse‐a review of Japanese studies on the clinical and neuroimaging aspects

Naoto Yamanouchi; Shin-ichi Okada; Kazuhiro Kodama; Toshio Sato

Organic solvents are some of the most frequently abused substances in Japan. Abuse is especially prevalent among young people. In this article, we review Japanese studies, along with those of other countries, on central nervous system impairment caused by chronic solvent abuse. Neuroimaging studies provided valuable information on this problem. Magnetic resonance imaging revealed T2 prolonged lesions in diffuse white matter which were related to neurological symptoms and cognitive dysfunction. Clinical observations indicated that neurological symptoms and their reversibility differed among patients. Histopathological studies similarly revealed variation in severity of brain damage reflected by demyelination and neuronal damage. The basis of these variations are yet to be elucidated along with their causes such as severity of dependence, composition of solvents, individual predispositions and starting age of abuse. Cerebral perfusion analyses revealed some regional decreases in blood flow. These decreases may occur earlier than white matter changes and may relate to psychiatric symptoms such as apathy and lack of initiative.

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