[Morphological study of glycogen particles observed in the minute structures of human brain tumors and normal mouse brain].
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Adult↗
Biomedical subjects
F Ikuta
Publications and source records attributed to F Ikuta.
The viral particles in the reactive cells of the brain induced by chemical carcinogens.
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Animals↗
Schwann cell responses during regeneration after one or more crush injuries to myelinated nerve fibres.
The responses of Schwann cells during regeneration of myelinated nerve fibres were studied ultrastructurally in the distal segment of mouse phrenic nerve after a single or repeated localized crush injury. Chronological observations on nerves after a single crush confirmed the occurrence of myelination of only single regenerating axons among many that appeared in individual Büngner bands. The redundant axon sprouts often showed the structural features of degeneration and decreased in number with time. During the process, supernumerary Schwann cells not related to myelin formation were produced. They commonly failed not only to make a one-to-one relationship with an axon, but they also failed to acquire a new basal lamina of their own. With time, they showed shrinkage of their cytoplasm and became arranged circumferentially around the myelinating axon with unipolar or bipolar cytoplasmic processes. Electron microscopic, quantitative assessment of the nuclear population of Schwann cells following repeated crushes up to four times, clearly indicated a progressive and predominant increase in the number of the supernumerary Schwann cells with the number of crushes. Also, they were found to form separate concentric cytoplasmic lamellae around the myelinating axons, developing structures resembling onion-bulbs. It was concluded that essentially the same regenerating process as that observed after a single crush was repeated following re-crush, thereby resulting in the successive accumulation of supernumerary Schwann cells around a myelinating axon.
Animals↗
Bilateral hypoplastic internal carotid arteries with multiple cerebral aneurysms.
A 60-year-old man with massive subarachnoid hemorrhage is reported. Radiologically, bilateral occlusion of the internal carotid arteries and multiple cerebral aneurysms of the saccular type were detected. Postmortem examination revealed that the internal carotid arteries were markedly diminutive and completely occluded by mesenchymal fibrous tissue. The pathogenesis of the diminutive internal carotid arteries and the cerebral aneurysms were briefly discussed.
Carotid Artery Thrombosis↗
A morphometric reevaluation of Huntington's chorea with special reference to the large neurons in the neostriatum.
In order to reevaluate the quantitative changes in the neostriatum of Huntington's chorea (HC), sections of the caudate head and putamen from 4 HC and 5 control cases were treated with Klüver-Barrera stain and the nuclear area of the neurons was measured by a digitizer. The number of neurons of different sizes was evaluated statistically. This study revealed a significant decrease in the number of large neurons (nuclear area; greater than 121 microns 2) as well as a severe decrease in the number of small neurons (nuclear area; less than 80 microns 2) in the neostriatum of HC. There was a parallel degree of neuronal loss in the upper and lower portions of both caudate head and putamen. The degree of neuronal loss was slightly more severe in the putamen than in the caudate head. The depletion of the large neurons was not correlated with the loss of small neurons. The number of medium-sized neurons (nuclear area; 81-120 microns 2) showed no statistically significant change.
Adult↗
Mitotic figures of glial fibrillary acidic protein-positive cells in the periphery of human brain abscess.
It has been unclear until now as to whether human astrocytes proliferate through mitosis or through amitosis, and little attention has been paid to the biological meaning of glial cell division. We examined an autopsy case of a 53-year-old man who died of brain abscesses and have found GFAP-positive mitotic cells in the zone between the abscess cavity and the reactive gliosis. The results suggest that human normal astrocytes which act in response to the brain abscess proliferate the process of mitosis, and become reactive to repair the lesions.
Astrocytes↗
Progressive supranuclear palsy with limbic system involvement: report of a case with ultrastructural investigation of neurofibrillary tangles in various locations.
An autopsied case of a 65-year-old woman with progressive supranuclear palsy (PSP) characterized by dementia, hallucination and delirium is described. On neuropathologic examination, widespread neurofibrillary tangles (NFTs) associated with neuronal cell loss and gliosis were observed in the basal ganglia, subthalamic nucleus and various brain stem nuclei, corresponding to the well-established pathology of PSP. In addition, a large number of NFTs with neuronal cell loss were shown in the hippocampus, parahippocampal gyrus, amygdaloid nucleus, subcallosal area, anterior perforated substance, cingulate gyrus and anterior olfactory nucleus. Ultrastructurally, NFTs observed in the periaqueductal central grey, locus ceruleus and hippocampus were composed almost exclusively of straight tubules. On the other hand, those in the amygdaloid and anterior olfactory nuclei were composed mainly of twisted tubules of Alzheimer type. NFTs composed of twisted tubules alone were not observed. The present case was considered as a rare peculiar type of PSP which showed massive systemic appearance of NFTs in the so-called limbic system.
Female↗