Nishio Nakamura

ANIMAL MODELS OF VASCULAR DEMENTIA WITH EMPHASIS ON STROKE‐PRONE SPONTANEOUSLY HYPERTENSIVE RATS

1. Two experimental models designed to reflect different aspects of vascular dementia (rats with cerebrovascular occlusion and rats with cerebral embolization) and stroke‐prone spontaneously hypertensive rats (SHRSP) have been evaluated. The focus was on SHRSP as a model for vascular dementia.

Immunohistochemical analysis of giant cell glioblastoma.

Giant cell glioblastoma (GCG) is one of a group of rare tumors in which the cell population is abnormally large and includes multinucleated cells of gigantic sizes. Immunohistochemical studies were performed on four GCG cases and found that all giant cells and/or tumor cells were positive for glial fibrillary acidic protein (GFAP), S‐100 protein, and vimentin, thus verifying the tumors glial origin. The nuclei of multinucleated giant cells of three adult cases were frequently immunostained for proteins expressed during the cell cycle (proliferating cell nuclear antigen (PCNA) and Ki‐67), thereby demonstrating the proliferative capacity of these cells. By contrast, those of a 12 year old girl expressed these cell cycle markers rather infrequently. Alpha I‐anti‐trypsin was detected with relatively high frequency in the giant cells, and its presence may explain their bizarre sizes and pericellular reticulin fiber formation. A literature review of 32 cases revealed that the GCG that occurs preferentially in young girls is a type of pleomorphic xanthoastrocytoma. By contrast, GCG in adult males has the same age incidence as ordinary glioblastomas and, as these, expresses high levels of cell cycle‐related proteins. Thus, GCG, which is subclassified morphologically as ordinary glioblastoma, has distinct biological and clinical characteristics, with that in children requiring re‐evaluation because of its similarities to pleomorphic xanthoastrocytoma.

Pathology of pure hippocampal sclerosis in a patient with dementia and Hodgkin's disease: The Ophelia syndrome

An archive autopsy case of a 50‐year‐old man who died of Hodgkins lymphoma had a 4‐year, 4‐month history of dementia. After radiochemotherapy, the lymphoma subsided except for involvement of the spleen, but the dementia remained. Neuropathological examination revealed that the pathology was confined to the hippocampus, both hippocampi showing sclerosis without inflammation. Neurons of sector cornu ammonis (CA) 1 were completely lost whereas moderate neuron loss was also observed in sectors CA3 and 4, and the dentate gyrus. Neurons of sector CA2 were relatively well preserved and the subiculum was intact. There was no evidence of global hypoxia, or of neurodegenerative disorders with pathological changes affecting the hippocampus. Although there was a long preneoplastic history, and no inflammatory changes were found at autopsy, the present case of hippocampal sclerosis could be included in the category of paraneoplastic limbic encephalitis associated with Hodgkins lymphoma or the Ophelia syndrome.

Changes in ambulation and drinking behavior related to stroke in stroke-prone spontaneously hypertensive rats.

In order to elucidate the behavioral changes related to stroke, ambulatory activity and water drinking were observed in stroke-prone spontaneously hypertensive rats (SHRSP). Age matched male SHRSP and Wistar Kyoto rats (WKY) were subjected to a 12 hour light and dark alternation cycle. Ambulation and drinking activity counts were determined simultaneously with an Ambulo-Drinkometer. Before stroke, ambulation and drinking activity counts in the dark phase (82%) were higher than those in the light phase (18%). Both parameters were well synchronized with the light and dark alternation cycle. With aging, daily ambulation decreased while daily drinking activity increased in SHRSP and WKY. Daily ambulation and drinking activity in 15 and 30 week old SHRSP were greater than those of WKY. It was demonstrated with an Ambulo-Drinkometer that SHRSP undergo specific behavioral changes before the onset of stroke. For instance, the 40-60 week old SHRSP showed significant individual variation in both ambulation and drinking activity. This desynchronization with the light and dark alternation cycle was followed by stroke. Twenty seven autopsies showed 11 cerebral infarctions, 10 cerebral hemorrhage and 6 cerebral hemorrhage with infarctions to be the causes of death.

Mitochondrial abnormalities in choroid plexus of leigh disease

Morphological study of the choroid plexuses in three patients with Leigh disease revealed a marked increase in the number of mitochondria in almost all of the choroidal epithelial cells. This finding is considered the morphological expression of a biochemical defect in the mitochondrial metabolism underlying Leigh disease, and the probable explanation for increased CSF levels of lactate and pyruvate in this disease.

Effects of mild hypercapnia on somatosensory evoked potentials in experimental cerebral ischemia.

In a previous report, the authors demonstrated the effectiveness of mild hypercapnia inenhancing decreased perfusion flow in ischemic, non-infarcted brain tissues. However, the previous worklacked in verification of improvement of suppressed brain function. Therefore, this report was attempted toevaluate the effect of hypercapnia on somatosensory evoked potential (SEP), using the similar ischemicmodel as previously. The results showed that mild hypercapnia of 43 to 55 mm Hg range was beneficial notonly for enhancing decreased perfusion flow but also for restoring suppressed SEP. This report seems to bethe first publication which verifies a presence of correlation between local cortical blood flow (LCBF) andSEP under mild hypercapnia in mildly to moderately ischemic brain tissues. Stroke Vol 15, No 2, 1984

An autopsy case of AIDS initially presenting with symptoms of myelopathy

An autopsy case of HIV encephalomyelopathy in a homosexual patient who initially presented with signs of myelopathy, such as urinary incontinence and spasticity of both legs, is reported. The pathological examination disclosed typical HIV encephalopathy with macrophages and multinucleated giant cells (MGC) in the cerebral white matter and loss of neurons of the cerebral cortex. The MGC contained HIV‐1 p24 antigen. The thoracic spinal cord was markedly atrophied with degeneration of both lateral tracts, and histologically characterized by gliosis and perivascular accumulation of macrophages. Vacuolar changes and HIV‐1 p24‐containing cells were not observed in the spinal cord. The present case indicates that myelopathy can occur as an initial sign in AIDS patients, even though its pathomechanism remains to be elucidated.