Taihei Miyakawa

Morphological Changes of Blood Vessels in the Brain with Alzheimer's Disease

Abstract: The pathological changes of microvessels in the cerebral cortex in Alzheimers disease were examined at the ultrastructural level.

Histopathological Changes of Chronic Alcoholism

The brains of six cases of chronic alcoholics without arteriosclerosis and the other diseases were examined histopathologically.

Electron microscopic study of experimental thallotoxicosis.

To adult male rats 2 mg per rat of thallium acetate: CH3 COOTl was given orally daily for six months. Clinically, the experimental rats revealed only alopecia and showed no neurological signs.

Classification of Senile Plaques by Three‐Dimensional Analysis

Abstract: We evaluated the number of each senile plaque subtype in Alzheimers brain by the usual two‐dimensional analysis using a single, methenamine silver stained section and three‐dimensional analysis using serial section reconstruction. The number of classic plaques was underestimated due to a lack of precision in the usual evaluating procedures (two‐dimensional analysis), while that of stellate deposits was overestimated. From these results, it was suggested that the three‐dimensional analysis by gapless serial sections was indispensable to examine and subclassify senile plaques.

An Autopsy Case of Cycloserine Poisoning

Cycloserine was given to a 29–year‐old girl with pulmonary tuberculosis for 500 days (total dose 250 g). Following this treatment, she began to show several psychiatric and neurological symptoms and died.

Familial Mitochondrial Encephalomyopathy with Stroke‐like Episodes and Episodic Disturbances of Consciousness: A Study of Pedigree Including Three Generations with Multisystemic Abnormalities

Abstract: We report here two cases in a family with pleomorphic clinical features which include mitochondrial myopathy, encephalopathy, stroke‐like episodes, episodic disturbances of consciousness and other multisystemic abnormalities. The other signs observed in multisystemic abnormalities were ophthalmoplegia, short stature, diabetes mellitus, diabetes insipidus, renal dysfunction, optic atrophy, retinal degeneration, impairment of hearing and mental retardation or deterioration. A symptomatological variation was observed in cases in the same family. It is suggested that these widely varying symptoms may be expressions caused by a common biochemical defect which involves different tissuesin different individuals in the family. The syndromes observed in the present cases were compared with other possibly‐related mitochondrial encephalomyopathies.

Mechanism of histopathological changes of nerve cells experimentally induced by chronic alcohol poisoning.

Experimental alcoholism was produced in rats by supplying them with 15% ethanol as the only source of liquid for a whole year.

Investigation Concerning Hallucinatory and Delusional States —In Connection With Hypofunction of Brainstem and Diencephalon

Among cases with hallucinatory and delusional states, two cases with rapid onset, hypotension and slight disturbance of consciousness were studied. Under hallucinatory and delusional states, EEG showed low amplitude rapid waves. Administration of haloperidol with arousal action caused disappearance of hallucination and delusion as well as rapid waves, indicated the role of decreased activity of lower brain area in the development of hallucinatory and delusional states.

Examination of β‐Protein Deposits in Alzheimer's Cerebral Cortices by Three‐Dimensional Observation

Abstract: We examined the location of β‐protein deposits (small diffuse plaques) in the cerebral cortices of Alzheimers patients and aged nondemented controls by observing the methenamine silver stained serial sections. Some vessels, astrocytes or neuronal elements existed near or within the diffuse plaques, and the preamyloids in the plaques were frequently detected in direct contact with vessels, astrocytes or neuronal elements. Although these findings do not demonstrate that the β‐protein within the senile plaques is produced in various cellular elements of the brain, they suggest some associations between β‐protein deposition and vessels, astrocytes or neuronal elements.

The effect of hyperthyroidism induced by thyroideum siccatum on the central nervous system: an electron microscopic study.

Ten adult male rats were administered orally with thyroideum siccatum every day to produce a hyperfunctional state of thyroid hormone. They were examined electron microscopically for the fine structure of the brain. Clinically, experimental rats lost in weight, manifested a hyperactive, irritative attitude, and were in an aggressive state. Electron microscopically, the nerve cells showed a slight increase in the number of mitochondria in the frontal cortex, spiral and petaloid variation of ER in the thalamus. The specific findings in the experimental rats were variations of synapse observed in the frontal and temporal cortex, gyrus hippocampi, and thalamus, centering around the hypothalamus. They included meandering of the presynaptic membrane, formation of vacuoles by the presynaptic membrane, saccate projection of this membrane to the postsynapse, and changes in vacuoles which were torn off and fell into the dendrite. These variations occurred in the synaptic membrane and ER, probably because synthesis of the membrane had been accelerated remarkably by the action of thyroid hormones. They were considered to have brought about abnormalities to the conductive and transmission system. They seemed to be closely related with emotional disturbances and psychic symptoms, since such variations were particularly apparent in the hypothalamus.