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Biomedical subjects

Y Hashizume

Publications and source records attributed to Y Hashizume.

At least 37 records · Page 2Linked to original sources
PubMed2000

Calpain inhibitor inhibits secretory granule maturation and secretion of GH.

Clathrin- and AP-1-coated buds are present on immature secretory granules of endocrine cells that mature into clathrin-uncoated granules. The mechanism of clathrin and adaptor protein uncoating has remained obscure. Benzyloxycarbonyl-L-leucyl-L-leucinal (ZLLal), a calpain inhibitor, reduced growth hormone (GH) secretion with intracellular accumulation, in a GH-secreting rat pituitary tumor cell. Pulse and chase demonstrated that ZLLal retarded the turnover of clathrin (Clt.H) and adaptins. ZLLal-treatment co-immunoprecipitated the increased amounts of GH with Clt.H and adaptins compared to control cells, suggesting the intracellular accumulation of immature secretory granules. Clt.H and adaptins were limited-proteolyzed by m-calpain in vitro, indicating that calpain may be involved partly in the maturation of secretory granules in endocrine cells via the process of clathrin uncoating.

Adaptor Protein Complex alpha Subunits↗
PubMed2000

Brainstem-type Lewy body disease presenting with progressive autonomic failure and lethargy.

The authors report an autopsy case characterized by progressive lethargy and autonomic failure with a distinctive pattern of occurrence of Lewy bodies. Autonomic dysfunction such as sleep apnea, orthostatic hypotension, dysuria, and hypohidrosis predominated with lethargy, whereas parkinsonism was not apparent. Numerous Lewy bodies were widely evident microscopically in brainstem nuclei and the intermediolateral cell columns of the spinal cord, as well as in the sympathetic ganglia, but were rare or absent in the cerebral cortex and other supratentorial structures. Marked neuronal loss was seen in the locus ceruleus, raphe nuclei, dorsal vagal nuclei, and intermediolateral cell columns, but neurons in the substantia nigra, other brain regions, and sympathetic ganglia appeared undiminished. This case represents a specific clinicopathologic form of Lewy body disease occurring predominantly in the brainstem, spinal cord, and sympathetic ganglia.

Autonomic Nervous System↗
PubMed2000

MELAS with the mitochondrial DNA 3243 point mutation: a neuropathological study.

We performed a neuropathological examination of the central nervous system from seven autopsied patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). Five of the seven cases were confirmed to have the mitochondrial DNA (mtDNA) 3243 point mutation. In addition to the changes reported previously, diffuse atrophy of the cerebral and cerebellar cortices, diffuse gliosis of cerebral and cerebellar white matter, and cactus formation of Purkinje cells were observed. Electron microscopy revealed accumulation of mitochondria in the cactus formations. These lesions are common in MELAS with the mtDNA 3243 point mutation, but cannot be explained solely by mitochondrial angiopathy, and suggest that intrinsic mitochondrial malfunction contributes to neuronal damage in MELAS pathology. Moreover, the pathological changes observed in the cerebellum suggest that cerebellar function should be evaluated more carefully at the clinical level.

Adult↗
PubMed2000

Morphological Purkinje cell changes in spinocerebellar ataxia type 6.

Spinocerebellar ataxia type 6 (SCA6) was recently identified as a form of autosomal dominant spinocerebellar ataxia associated with a small CAG repeat expansion of the gene encoding an alpha 1 A-voltage-dependent calcium channel gene subunit on chromosome 19p13. In this study 50-microm-thick sections of cerebellar tissue from one patient with SCA6 were subjected to free-floating immunohistochemical staining with calbindin-D and parvalbumin antibodies. Severe loss of Purkinje cells was found, particularly in the vermis, and various morphological changes in Purkinje cells and their dendritic arborizations were demonstrated. Many of the remaining Purkinje cells were found to have heterotopic, irregularly shaped nuclei, an unclear cytoplasmic membrane outline, and somatic sprouts. Increased numbers of spine-like protrusions from swelling dendritic arborizations were found in the molecular layer. The axonal arrangement was disordered, and many torpedos were found in the granular layer and white matters. These morphological changes are completely different from those observed in paraneoplastic cerebellar degeneration (PCD) and multiple system atrophy (MSA) and are considered to be related to the genetic abnormality that causes abnormal development of Purkinje cells.

Aged↗
PubMed2000

Differential somatic CAG repeat instability in variable brain cell lineage in dentatorubral pallidoluysian atrophy (DRPLA): a laser-captured microdissection (LCM)-based analysis.

Employing a laser-captured microdissection (LCM), we have investigated the somatic instability of CAG repeats in the variable brain cell lineage in three patients with dentatorubral pallidoluysian atrophy (DRPLA). LCM enables the isolation of single lineage brain cells for subsequent molecular analysis. We have found that CAG repeat size and the range of CAG repeats in the cerebellar granular cells is smaller than those in cerebellar glial cells. Similarly, those in the cerebral neuronal cells are significantly shorter than those in cerebral glial cells. These data directly indicate that the CAG repeat is relatively more stable in neuronal cells than in glial cells. Furthermore, cerebellar granular cells show significantly smaller main CAG repeat size and CAG repeat range than either Purkinje cells or cerebral neuronal cells, suggesting that somatic instability in the CAG repeat is markedly variable even among the different types of neuronal populations. The cell-specific CAG repeat instability may thus be more complex than has previously been considered. LCM is a powerful tool for elucidating the mechanism of the triplet repeat instability of each cell type.

Adult↗
PubMed2000

Crescentic glomerulonephritis with positive antineutrophil cytoplasmic autoantibody specific for myeloperoxidase associated with autoimmune hemolytic anemia and thrombocytopenic purpura.

A 41-year-old woman was admitted to the hospital with severe uremia, hemolytic anemia, and thrombocytopenic purpura. Emergency hemodialysis with plasmapheresis was started in view of consideration of hemolytic uremic syndrome (HUS), which resulted in improvement of renal function and platelet count. Positive antineutrophil cytoplasmic autoantibody specific for myeloperoxidase (MPO-ANCA) suggested crescentic glomerulonephritis, which was pathologically evidenced by renal biopsy. The diagnosis of MPO-ANCA associated crescentic glomerulonephritis with autoimmune hemolytic anemia (AIHA) and thrombocytopenic purpura were confirmed. Three courses of steroid pulse therapy with heparin were successfully performed, followed by oral prednisolone and warfarin. Such a case has not been previously reported to our knowledge.

Adult↗
PubMed2000

Endothelin-1 in the brain of patients with galactosialidosis: its abnormal increase and distribution pattern.

Endothelin-1 is a peptidic substrate in vitro of lysosomal protective protein/cathepsin A (PPCA) with serine carboxypeptidase activity. Endothelin-1-specific immunoreactivity has been demonstrated to be markedly increased and distributed abnormally in the neurons and glial cells within autopsied brain regions, including the cerebellum, hippocampal formation, and spinal cord, of patients affected with galactosialidosis, a human PPCA deficiency. The genetic defect of the endothelin-1 degrading activity of PPCA is suggested to cause some of the neurological abnormalities of this disease.

Adenosine Diphosphate↗
PubMed2000

[An autopsy case of bilateral carotid artery occlusion with repetitive epilepsy and brain atrophy in a senile patient].

A 67-year-old man was referred to us for tonic-clonic convulsions. A review of his history revealed that he had been hospitalized for loss of consciousness, hypotension, and suspected apoplexy at age 67. He had experienced prior tonic-clonic convulsions at age 72 and age 74. He had malaria and tuberculosis in his history but had been otherwise generally well. Physical examination was normal, and his blood pressure was 100/80 mmHg. Laboratory findings were normal except alcalinephosphatase (292 U/l) and gamma-glutamyl transpeptidase(60 U/l). Neurological examination showed alert consciousness, mild upper gaze palsy, slight right-side hemiparesis and left Babinski signs was present. Cranial magnetic resonance imaging showed no abnormality, but cerebral angiography revealed bilateral carotid artery occlusion. There were abundant leptomeningeal anastomoses, and the posterior communicating artery was supplied by the left vertebral artery. Electroencephalography showed a spike wave in the temporal lobe and rebuild-up phenomenon in the right hemisphere. Brain atrophy in the anterior and temporal lobes progressed, and the patient experienced gradual disorientation, delirium and hypobulia. He was eventually bedridden. He also demonstrated repetitive tonic-clonic convulsions. After one convulsion, he remained unconscious and died of pneumonia. Autopsy revealed thickening of the intima and internal elastic lamina in the occluded internal carotid artery. The anterior and middle cerebral arteries showed the same pathological changes. Multiple small infarctions restricted to grey matter were present in the cerebral cortex and may have caused the progressive brain atrophy. There was no myelin pallor in the white matter of the cerebrum. Atherosclerotic changes, senile plaque, and neurofibrillary tangles were seen but were within normal limits. These pathological findings were strongly suggestive of moyamoya disease.

Aged↗
PubMed2000

[An autopsy of parkinsonism after solitary living in Guam Island for 28 years].

The autopsy findings of an 82-year-old man with history of solitary living in the jungle of Guam, the endemic area of parkinsonism-dementia complex(PDC), for 28 years was reported in this paper. When he was 75 years old, about 20 years later to have come back to Japan, he developed parkinsonism. He noticed bradykinesia and was pointed out masked face, rigidity and tremor in his right hand. After 2 years, he was diagnosed as Parkinson's disease under the third degree of Hoehn-Yahr criteria. He also showed mild cognitive dysfunction, but no pyramidal signs, muscle atrophy of fasciculation at all. Anti-parkinsonian drugs were effective for his motor symptoms. He admitted at age 82 because of anorexia, and died after 3 months. Neuropathological study disclosed neuronal loss and gliosis with Lewy bodies in the substantia nigra, locus coeruleus and dorsal vagal nucleus. There were cortical type Lewy bodies in the limbic system and scanty amount in the neocortex. A few neurofibrillary tangles(NFT) were found in the hippocampus and parahippocampal gyrus, but no dominancy in the second or third layers of the cerebral cortex as reported in PDC. Senile plaques were not observed at all. Although the exact cause of PDC has not been clarified, environmental factors such as water or food seem to influence on the outcome of PDC. However, the pathological findings of the present case were compatible to those of idiopathic Parkinson's disease. Thus it is a very important fact that the present case was not suffered from PDC in spite of his long residence in the endemic area of Guam.

Aged↗
PubMed2000

[An autopsy case of corticobasal degeneration without prominent cortical pathology--an imitator of progressive supranuclear palsy].

We describe an autopsy case of parkinsonism with bradykinesia, muscle rigidity, and dementia as major symptoms. The patient had developed bradykinesia at the age of 62, and then muscle rigidity, a parkinsonian posture, bradylalia, and dementia gradually appeared. Neurological examination revealed rigidity in the neck and limbs, with motion and speech being generally slow. He lacked involuntary movements including alien hand, tremor, chorea, and dystonia. Vertical gaze palsy, both upward and downward was noted, but other cranial nerves were intact. He was diagnosed as suffering from PSP clinically based on vertical gaze palsy, bradykinesia, instability on standing and gait, and dementia. Levodopa was only transiently effective. Within three years he became bed-ridden and in a state of akinetic mutism. At age 65 he died from pneumonia. Neuropathology revealed severe neuronal degeneration and gliosis in the substantia nigra. Because atrophy of the tegmentum of brainstem, dentate nuclei, inferior olivary nuclei was very mild and Alzheimer neurofibrillary tangles in the brainstem were relatively few, PSP was ruled out. Cortical neuronal degeneration was not apparent, but in the deep layer of cingulate gyrus, frontal lobe, and insula, there were several ballooned neurons. Gallyas-Braak silver staining showed no tuft-shaped astrocytes, specific for PSP, but it disclosed astrocytic plaques in the basal ganglia and the cerebral cortex. At present, astrocytic plaques are recognized as a hallmark of corticobasal degeneration (CBD), along with ballooned neurons in the cerebral cortex. The present case thus illustrates that CBD has a wide spectrum and may include cases in which degeneration of cerebral cortex is very mild.

Aged↗
PubMed1999

Age-related morphologic changes of the central canal of the human spinal cord.

To elucidate the role of the human central canal on the physiology and pathogenesis of acquired syringomyelia, we analyzed the age-related morphologic changes in the normal human central canal of the spinal cord. The subjects included 158 autopsy cases ranging in age from 1 week postnatally to 116 years of age. Each segment of the whole spinal cords was investigated from the C3 to S3 levels. The microscopic pictures of the central canal were classified as patent or occluded at each level for each age decade. The patency rate under 1 year of age was 100% in almost all the segments, which markedly decreased in the second decade, and the canals were occluded in all the segments with advancing age. According to the longitudinal pattern of the central canal occlusion, 19 of 20 cases where the canals were patent in all segment levels were less than 10 years of age. Cases in which the canals were occluded in all segment levels appeared in the second decade, and their number increased gradually with advancing age. The occlusion of the central canal started at the T6 and L5 to S2 levels. We suggest that the central canal does not function after infancy because of its occlusion, and that it is not involved in the development of syringomyelia in adult patients.

Adolescent↗
PubMed1999

Multiple system atrophy with remarkable frontal lobe atrophy.

The autopsy findings of a multiple system atrophy (MSA) patient with remarkable frontal lobe atrophy are described. The patient was a 65-year-old woman with a 13-year history of untreatable parkinsonism, dysautonomia and progressive motor aphasia. The brain weight was 810 g, and there was remarkable atrophy of the cerebrum predominantly in the frontal lobe, striatum, pons and cerebellum. Microscopic examination revealed a preserved cortical structure with laminar gliosis in the sixth layer of the precentral and superior frontal gyri of the frontal lobe, and postcentral gyrus and inferior parietal lobule of the parietal lobe. The second layer of the cortices of these regions were also revealed to be in a spongy state, and mild cell loss was seen in the fifth and six layers. The frontal lobe white matter showed a mild loss of myelinated fibers and axons, and mild gliosis. Glial cytoplasmic inclusions (GCIs) were abundantly observed in the deep layer of the cortex in the regions mentioned above, and were more abundant in the white matter of the frontal and parietal lobes, callosal body, and internal, external and extreme capsules. There was severe degeneration in the olivopontocerebellar and striatonigral systems, and GCIs in widespread regions of the brain. No Pick bodies, Lewy bodies, ballooned neurons, senile plaques, or significant amounts of neurofibrillary tangles were detected. There were no vascular changes. Thus, this was a verified MSA patient with progressive aphasia and remarkable frontal lobe atrophy. We indicate a possible involvement of the cerebral lobes in MSA.

Aged↗