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Featured researches published by S. Yokoi.


Psychiatry Research-neuroimaging | 1987

Three subtypes of chronic schizophrenia identified using 11C-glucose positron emission tomography

Hideji Kishimoto; Hiroshi Kuwahara; Shiro Ohno; Osamu Takazu; Yuki Hama; Chiaki Sato; Takayoshi Ishii; Yuji Nomura; Haruhiro Fujita; Toshiro Miyauchi; Masaaki Matsushita; S. Yokoi; Masaaki Lio

The authors used positron computed tomography (CT) and 11C-labeled glucose to measure brain glucose utilization in 20 chronic schizophrenic patients (18 men, 2 women, mean age 38) and 5 male control subjects (mean age 38). Positron emission tomography (PET) revealed at least three subtypes: hypofrontal (type A), hypoparietal (right-sided disturbance in right-handed and left-sided disturbance in left-handed patients) (type B), and normal (type C). The significant count reduction in the frontal lobe (Brodmanns area 10) in type A patients was 38%, while that in the parietal lobe (Brodmanns area 40) in type B patients was 26% in each lobe of the brain.


Psychiatry Research-neuroimaging | 1987

11C-glucose metabolism in manic and depressed patients

Hideji Kishimoto; Osamu Takazu; Shiro Ohno; Tetsuaki Yamaguchi; Haruhiro Fujita; Hiroshi Kuwahara; Takayoshi Ishii; Masaaki Matsushita; S. Yokoi; Masaaki Iio

The authors used positron emission tomography (PET) and 11C-labeled glucose to study 15 unmedicated patients with affective disorders and 7 control subjects. Diagnoses of affective disorders were based on DSM-III criteria, and symptomatology was evaluated by the Hamilton Rating Scale for Depression. Blood counts of 11C in both unipolar and bipolar patients did not differ from those in controls after oral administration of 11C-glucose. By contrast, brain counts of 11C in unipolar depressed patients were significantly lower, whereas those in bipolar manic patients were significantly higher, than in normal controls.


Acta Neuropathologica | 1992

Gerstmann-Sträussler syndrome — A variant type: amyloid plaques and Alzheimer's neurofibrillary tangles in cerebral cortex

Naoji Amano; Saburo Yagishita; S. Yokoi; Y. Itoh; Jun Kinoshita; Toshio Mizutani; Takeshi Matsuishi

SummaryThis report presents a variant of Gerstmann-Sträussler syndrome (GSS). A 53-year-old female had developed slowly progressive dementia and atactic gait since the age of 45. No myoclonic jerks and periodic synchronous discharges were observed throughout the illness. The neuropathological study revealed that many amyloid plaques and widespread Alzheimers neurofibrillary tangles (NFTs) appeared in the cerebral cortex. Characteristically, the plaques reacted with anti-prion protein and none of them reacted with anti-β protein, and they were made of many components, including amyloid cores, macrophages laden with lipid granules and/or degenerated neurites. Neuropil threads were seen mainly in amyloid plaques. Moreover, plaques appeared which were confluent and laminar in arrangement in the fifth and sixth cortical layers and had a close relationship to the neuronal loss. There was no spongiform change in the cerebral cortex or cerebellum. The cerebellum was almost intact except for a few amyloid plaques. Ultrastructurally, some of the plaques simulated kuru plaques and others had many degenerated neurites possessing paired helical filaments and other accumulated organelles. GSS has been proposed to include cases with progressive ataxia, dementia and massive multifocal plaques in the brain with or without cerebral spongiform changes. The case presented here is a very peculiar case of GSS. Recently, similar cases have been reported in some large families, diagnosed as familial Alzheimers disease. These cases may be a telencephalic form with numerous NFTs of GSS.


Acta Neuropathologica | 1987

Nasu-Hakola's disease (membranous lipodystrophy)

Naoji Amano; Kiyoshi Iwabuchi; H. Sakai; Saburo Yagishita; Y. Itoh; Eizo Iseki; S. Yokoi; Nobutaka Arai; J. Kinoshita

SummaryAn autopsy case of Nasu-Hakolas disease (membranous lipodystrophy) is reported. A 43-year-old Japanese man, whose parents were not consanguineous, had been suffering from frequent long bone fractures since the age of 10. Neuropsychiatric symptoms, which were characterized by euphoria, disturbance of attention and dementia, appeared at his thirties and generalized and/or localized seizures and apallial syndrome at the later stage. The neuropathology revealed diffuse leukoencephalopathy of the cerebrum. The peculiar aspects in this case were membranocystic changes in the lungs [Yagishita et al. Virchows Arch [A] 408:211–217 (1985)], diffuse degeneration of the cerebral cortex, chiefly in frontal and temporal lobes, and many axonal spheroids throughout the cerebral cortex. The ultrastructure of spheroids in the cerebral cortex demonstrated aggregations of mitochondria, dense bodies and minute concentric bodies and a small amount of neurofilaments.


Neuropathology and Applied Neurobiology | 1988

A case of familial, atypical Alzheimer's disease: immunohistochemical study of amyloid P-component.

Eizo Iseki; N. Amano; T. Matsuishi; S. Yokoi; Nobutaka Arai; S. Yagishita

The presence of amyloid P-component (AP) in the amyloid plaques of a case of familial, atypical Alzheimers disease was examined by means of the anti-AP immunoperoxidase method. Many amyloid plaques stained strongly positive for AP, so that they were analogous in AP stainability to those of Creutzfeldt-Jakob disease.


Acta Neuropathologica | 1983

Neuropathological findings of an autopsy case of adult ?-galactosidase and neuraminidase deficiency

N. Amano; S. Yokoi; M. Akagi; M. Sakai; S. Yagishita; K. Nakata

SummaryAn autopsy case of a Japanese male with familial β-galactosidase and neuraminidase deficiency is reported. The clinical picture was characterized by adult onset, a gargoyle-like face, cerebellar ataxia, myoclonus, convulsions, retinal degeneration and cortical blindness.Histopathologically, most neurons seemed to have become degenerated in the whole cerebral cortex. Moreover, the calcarine cortex appeared spongy with depopulation of nerve cells. Stuffed neurons or neuronal storage changes were found throughout the brain, especially in the motor nuclei of the spinal cord and brain stem.The inclusions in the stuffed neurons revealed various profiles on the electron microscope. They were composed of membranous lamellar and/or multilamellar structures, often accompanying vacuoles and reminiscent of lipofuscin-like profiles.


Acta Neuropathologica | 1987

Tardive dyskinesia with inflated neurons of the cerebellar dentate nucleus

Nobutaka Arai; N. Amano; Eizo Iseki; S. Yokoi; A. Saito; Y. Takekawa; Kazuaki Misugi

SummaryFour autopsied cases of tardive dyskinesia manifesting oral hyperkinesia revealed markedly inflated neurons in the cerebellar dentate nucleus (DN), which had not been described previously. The inflation of the neurons was proved to be statistically significant (P<0.01) by morphometric study. The nuclei were usually situated in the central portion of the cytoplasm. This inflated change was different from both central chromatolysis and grumose degeneration of the DN, typically observed in progressive supranuclear palsy and dentatorubropallidolysian atrophy, and seemed to be easy to miss without careful observation, since neuronal loss and gliosis were very mild in the DN. Among a few autopsied cases of tardive dyskinesia reported previously, degeneration of the DN was described in only two. It is believed, however, that the inflated neurons of the DN may not be so rare and may be related to the occurrence of some involuntary hyperkinesia, especially oral hyperkinesia following some neurotoxic disorders and/or neuroleptic medications.


Journal of the Neurological Sciences | 1988

Three categories of the degenerative appearance of the human cerebellar dentate nucleus

Nobutaka Arai; Naoji Amano; Kiyoshi Iwabuchi; Saburo Yagishita; S. Yokoi; Atsushi Saito; Kazuaki Misugi

This morphometric and morphological study demonstrates 3 categories (types A, B and C) of degenerative feature in the cerebellar dentate nucleus. Type A is characterized by neuronal loss, astrocytosis and granular and/or amorphous argyrophilic change around the neurons and neuronal processes, and this type was thought to be synonymous with the so-called grumose degeneration of the DN. Type B is characterized by extensive neuronal loss and astrocytosis without argyrophilic change, and it was considered that many diverse factors were responsible for type B. Type C features marked swelling of the neurons without neuronal loss, astrocytosis or argyrophilic change. The Purkinje cells were not involved in type A and C, but severely damaged in type B. Clinically, type A was observed in progressive supranuclear palsy and dentatorubropallidoluysian atrophy, type B extensively in many diseases including anoxic, toxic and infectious disorders, and type C in tardive dyskinesia manifesting with oral hyperkinesia. Types A and C may be more or less specific signs of degeneration of the dentate nucleus, whereas type B appears to be non-specific.


Acta Neuropathologica | 1983

Pleomorphic Intra-neuronal Polyglucosan Bodies Mainly Restricted to the Pallidium

Saburo Yagishita; Y. Itoh; T. Nakano; Naoji Amano; S. Yokoi; O. Hasegawa; T. Tanaka

SummaryA rare case with pleomorphic intra-neuronal polyglucosan bodies is reported. A 45-year-old man died of gastric carcinoma with extensive visceral involvement. The autopsy showed numerous intra-neural pleomorphic PAs-positive deposits reminiscent of Bielschowsky bodies in the lateral segments of the pallidum, substantia nigra, and brain stem on both sides. Their histochemical properties were consistent with polyglucosan. The bodies were ultrastructurally composed of filamentous structures and seen in perikarya, axons, and dendrites. Occasionally, spotty electron-dense material was seen in the center of the bodies. The filaments were selectively stained with thiocarbohydrazide method after Thiéry, indicating their chief component as glucose polymers. The bodies are compared with Bielschowsky bodies, Lafora bodies, corpora amylacea, and related bodies, and their nature and significance are briefly discussed.


Acta Neuropathologica | 1987

A case of adult neuronal ceroid-lipofuscinosis with the appearance of membranous cytoplasmic bodies localized in the spinal anterior horn

Eizo Iseki; N. Amano; S. Yokoi; Y. Yamada; Kyoko Suzuki; M. Yazaki

SummaryAn autopsy case of adult neuronal ceroid-lipofuscinosis was examined. The clinical picture was charaterized by gait disturbance, bulbar palsy and dementia. Histopathologically, diffuse neuronal loss was found throughout the central nervous system. The remaining neurons, predominantly in the motor nuclei of the spinal cord and brain stem, were swollen with storage material. Observed under the electron microscope the storage material showed various ultrastructures, such as lipofuscin-like bodies, pleomorphic lipid bodies, curvilinear profiles and finger-print profiles, in different regions of the central nervous system. In the ballooned neurons of the spinal anterior horn, many membranous cytoplasmic bodies and curvilinear profiles were intermingled within the same cell and were continuous with each other. Biochemically,N-acetyl neuraminic acid content was significantly increased in the spinal anterior horn. These findings suggest the localized increase of ganglioside in that region.

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N. Amano

Yokohama City University

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Nobutaka Arai

Yokohama City University

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Kazuaki Misugi

Yokohama City University

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