Junzo Koizumi
University of Tsukuba
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Featured researches published by Junzo Koizumi.
Acta Neuropathologica | 1992
Katsuyoshi Mizukami; Megumi Sasaki; Toshihito Suzuki; Hiroyasu Shiraishi; Junzo Koizumi; N. Ohkoshi; Takesaburo Ogata; N. Mori; S. Ban; Kenji Kosaka
SummaryAn autopsy case of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) is reported. It presented with generalized muscle atrophy, stroke-like episodes, schizophrenia-like mental disorder and progressive dementia. Serum lactate and pyruvate levels were high. In the biopsied muscles, ragged-red fibers were observed by light microscopy and aggregation of abnormal mitochondria with paracrystaline formation by electron microscopy. The most characteristic neuropathological findings were infarct-like lesions widespread in the cerebral cortex. In addition, this case showed some unusual pathological features: (1) diffuse moderate fibrillary gliosis in the whole cerebral and cerebellar white matter, which might have been due to metabolic disturbances; (2) several focal lesions with demyelination and numerous spheroids in the pontocerebellar fibers; and (3) marked degeneration of the posterior columns and spinocerebellar tracts. Electron microscopic examination revealed that abnormal mitochondria were markedly aggregated in smooth muscle cells and endothelium of the cerebral and cerebellar blood vessels. These fine structural findings suggest a “mitochondrial angiopathy”.
Neuroradiology | 1990
Toshihito Suzuki; Junzo Koizumi; Hiroyasu Shiraishi; N. Ishikawa; Kojiro Ofuku; Megumi Sasaki; Takafumi Hori; N. Ohkoshi; Izumi Anno
SummaryA case of mitochondrial encephalomyopathy (MELAS) with mental disorder is reported. The SPECT study using123I-iodoamphetamine (IMP) and MRI study revealed abnormality in the left parieto-occipital areas without abnormality in the brain CT or brain scintigram. These findings suggest a localized dysfunction of the brain capillary endothelium in association with the cerebral involvement of mitochondrial encephalomyopathy.
Acta Psychiatrica Scandinavica | 1990
Toshihito Suzuki; Junzo Koizumi; T. Moroji; Kenichi Sakuma; Masashi Hori; Takafumi Hori
The Pisa syndrome is not yet well characterized, although there have been increasing reports on its prevalence and the clinical features of drug‐induced dystonia. In this report, we present 20 cases of the Pisa syndrome and discuss the clinical symptoms compared with those of classical types of drug‐induced dystonia. The Pisa syndrome may occur not only as a subtype of acute dystonia but also as a subtype of tardive dystonia. Abnormal findings on brain CT were noted in both acute and tardive types of the Pisa syndrome, indicating that, like tardive dystonia, the Pisa syndrome may be associated with cerebral lesions. Young female patients were susceptible to both acute and tardive types of the Pisa syndrome, but the prevalence of both types of dystonia was inconsistent in these patients. Thus, it seems likely that very complicated pathophysiological changes in the brain are involved in the development of the Pisa syndrome.
Biological Psychiatry | 1992
Toshihito Suzuki; Junzo Koizumi; Takashi Moroji; Hiroyasu Shiraishi; Takafumi Hori; Atsuomi Baba; Nobutoshi Kawai; Koji Tada
The effects of long-term anticonvulsant therapy on copper (Cu), zinc (Zn), and magnesium (Mg) in the serum and hair were investigated in epileptics. Hair concentrations of Cu in both male and female epileptics, Zn in male epileptics, and Mg in female epileptics were significantly decreased when compared with those of age-matched and gender-matched controls. Hair Cu concentrations were significantly decreased in male epileptics; a significant decrease in hair Mg concentration was observed in female epileptics when compared with schizophrenics. An increased serum Cu concentration was found in female epileptics and a decreased Zn concentration was found in male epileptics. These findings suggest that long-term anticonvulsant therapy could induce alterations in both the metabolism and distribution of Cu, Zn, and Mg.
Computerized Medical Imaging and Graphics | 1994
Nobutoshi Kawai; A. Ellaba; Katsuyoshi Mizukami; T. Sakai; Hiroyasu Shiraishi; Junzo Koizumi
CNS changes in a case with general paresis were investigated by X-ray computed tomography (CT), Magnetic resonance (MR), and single photon emission computed tomography (SPECT). CT and MR showed a mild degree of diffuse cortical atrophy and the dilatation of lateral ventricles with no signs of ischemic lesions or inflammations. On the other hand, SPECT using 123I-N-isopropyl-p-iodoamphetamine (123I-IMP demonstrated marked reduction of the cerebral blood flow especially in the bilateral frontal and temporal cortices. Moreover, the reduction of the blood flow was significantly improved after the antisyphilitic therapy, correlated with the improvement of the mental disorders. These observations suggested that the SPECT is a useful method to evaluate the brain dysfunctions, and to assess the effect of antisyphilitic therapy in the patients with general paresis.
Biological Psychiatry | 1993
Toshihito Suzuki; Takashi Moroji; Takafumi Hori; Atsuomi Baba; Nobutoshi Kawai; Junzo Koizumi
The effects of chronic methamphetamine (MAP) administration (at a dose of 4 mg/kg for 14 days) on [3H]pCCK-8 binding sites in the rat brain were investigated by an in vitro quantitative receptor autoradiographic technique. The number of [3H]pCCK-8 binding sites was significantly reduced in layers III and IV of the medial frontal, anterior, and posterior cingulate cortices, in layers II-IV of the retrosplenial cortex, in layers III-VI of the dorsal insular cortex, and in the reticular nucleus of the thalamus, compared to these numbers in a control group of rats that received physiologic saline. Further, chronic methamphetamine administration led to a significant increase in the number of these binding sites in layer I of the entorhinal cortex. These findings indicate the CCK peptides in the limbic lobe may be closely related to the development of the behavioral changes associated with methamphetamine sensitization. In addition, these results provide supporting evidence for the involvement of the limbic system in the pathophysiology of schizophrenia.
Computerized Medical Imaging and Graphics | 1992
Katsuyoshi Mizukami; Hiroyasu Shiraishi; Yoshiro Tanaka; Yasushi Terashima; Nobutoshi Kawai; Atsuomi Baba; Tetsuaki Arai; Junzo Koizumi
CNS changes in three cases of neuro-Behçets disease were observed by computed tomography (CT), magnetic resonance (MR) and single photon emission computed tomography (SPECT). The present study illustrates the reversibility of lesions in the brain stem with MR, while CT failed to show any abnormal findings in the region of the disease. We conclude that MR is a quite useful method to detect lesions in the brain stem and to evaluate the effects of treatment in neuro-Behçets disease. SPECT is also an important method for the evaluation of dementia recognized in neuro-Behçets disease.
Psychiatry and Clinical Neurosciences | 1990
Takafumi Hori; Toshihito Suzuki; Yasushi Terashima; Nobutoshi Kawai; Hiroyasu Shiraishi; Junzo Koizumi
Abstract: A 64‐year‐old male with herpes simplex encephalitis had shown somnambulism and memory disturbance for nine months before consciousness disturbance appeared. Brain CT, MR and SPECT revealed lesions in the right temporal lobe. The atypical clinical course of this patient, including chronkity and focal symptom, is discussed.
Psychiatry and Clinical Neurosciences | 1993
Masashi Hori; Hiroyasu Shiraishi; Junzo Koizumi
Abstract: During the 12‐year period of retrospective observation, 38 cases of 93 major depressive inpatients were delusional and the remainders were nondelusional. We evaluated the differences on several variables, especially about suicide, between the two groups. The mean age at the onset of illness of delusional depressive patients was higher than that of nondelusional ones. The incidence of psychomotor retardation was lower in the former group than in the latter. The frequency of suicidal ideation and suicidal attempts were higher in the former group than the latter. The suicidal methods in the delusional depressives tended to be more active and violent than those in nondelusional depressives and were supposed to have a twofold mortality than those in the nondelusional ones. We discussed this high rate of suicides of delusional depression from the viewpoint of disinhibition of psychomotor retardation, chronicity, partial affinity of delusional depressives to schizophrenics and neuroendocrinological perspective.
Psychiatry and Clinical Neurosciences | 1992
Hiroyasu Shiraishi; Junzo Koizumi; Toshihito Suzuki; Naomi Yamaguchi; Katsuyoshi Mizukami; Masashi Hori; Yoshiro Tanaka
Abstract: Five cases with eating disorders (one case with anorexia nervosa alone, 4 cases with anorexia nervosa and bulimia nervosa) complicated with schizophrenia and 3 cases of bulimia nervosa complicated with schizophrenia were reported. The eating disorders and schizophrenia were diagnosed according to the diagnostic criteria of DSM‐III‐R. As to the type of schizophrenia, 4 patients were of an undifferentiated type and 4 cases were of a disorganized type. Regarding the prepsychotic personality, 6 of the 8 cases showed schizothyme personality traits. All the patients showed depressive symptoms which are relatively common in eating disorders. In all the patients, significant social or school life difflculties persisted and a resumption of premorbid functioning was not seen. The possibility of an afflnity between anorexia nervosa and schizophrenia was discussed.