Biomedical subjects

M Onaya

Publications and source records attributed to M Onaya.

9 recordsLinked to original sources

PubMed2001

Symmetrical necrosis of the solitary tract nuclei as a contributory cause of death.

A 64-year-old man died in spite of surgery 4 days after attempting suicide. He first tried to hang himself with a rope and when the hanging did not succeed, he cut his throat with a knife. The autopsy showed four sutured cervical wounds with laryngeal wounds but without associated important vascular injury. The neuropathological study revealed two watershed-type haemorrhagic infarcts, involving the left occipital lobe and the left cerebellum. It also showed a symmetrical necrosis of solitary tract nuclei in the medullary tegmentum. Such a lesion is likely to result from sudden acute transient circulatory failure and might have played a role in the secondary autonomous cardiac and respiratory dysfunctions following a non-lethal trauma.

Aged↗

PubMed1996

Chemonucleolytic effects of chondroitinase ABC on normal rabbit intervertebral discs. Course of action up to 10 days postinjection and minimum effective dose.

STUDY DESIGN: This study demonstrated the chemonucleolytic effects of chondroitinase ABC and its histologic and biochemical background. OBJECTIVES: To determine the course of chondroitinase ABC action on normal rabbit discs, and to find its minimum effective dosage. SUMMARY OF BACKGROUND DATA: No previous study has assessed the chemonucleolytic action of chondroitinase ABC in a time- and dose-dependent manner. This study also investigated the biochemical causes of radiologic and histologic changes in the discs. METHODS: Rabbits were injected with 4 U of pharmaceutical-grade chondroitinase ABC intradiscally. They were radiologically and histologically observed, and biochemical analyses of the discs were conducted on days 1, 3, 5, 7, and 10 postinjection in the time course study. Different doses of chondroitinase ABC were injected, and radiologic observations and water content of the discs were measured in the dose-finding study. RESULTS: The time course study revealed that the chondroitin sulfate content of discs significantly decreased from day 1 postinjection until the end of the experimental period. The weight and water content of the nucleus pulposus decreased on day 3, and disc space narrowing was observed from the day after injection. The dose-finding study showed that a dose of 0.0002 U/disc still induced disc space narrowing and a decrease in water content. CONCLUSIONS: Chondroitinase ABC is estimated to have a chemonucleolytic effect at least by day 3 postinjection at a dose level of 0.0002 U/disc or higher in rabbits.

Animals↗

PubMed1995

[A case of diffuse brain injury involving the medial part of the brain--its difference from diffuse axonal injury].

A 30-year-old male clinico-pathological case survived for 1 year and 9 months after being hit by a truck while riding on his motorbike on Aug. 21, 1988. On admission, his consciousness level was 5 according to the Glasgow Coma Scale, and a traumatic intraventricular hemorrhage and cerebral contusion were revealed by CT scanning. He underwent immediately an operation in order to drain blood from the ventricles at which time a right side dominant quadriplegia was noted. He made a gradual improvement and by January 1989 was able to tell us his name and address correctly. However, he remained incontinent and bedridden owing to the contracture of joints. He was put on rehabilitation exercises in March 1989 which trained him to operate a wheelchair. In April 1990 he regained urinary control, but was remarkably devoid of will power, perseverance and memory. He expired of pneumonia on May 11, 1990. At autopsy, his brain weighed 1180g. The cerebral convexity was discolored, especially the rectal gyri and bilateral olfactory bulbs were brownish-yellow. Old gross contusional scars were observed on the left rectal and orbital gyri, and the 3rd ventricle and inferior horns of the lateral ventricles were enlarged. Holzer's method revealed fibrillary gliosis in the corpus callosum, fornix, cingulate gyrus and a part of the caudate nucleus adjacent to the thalamus. Microscopically, axons were seen to be disrupted in the corpus callosum as well as in the anterior commissure, having the appearance of macrophages. (ABSTRACT TRUNCATED AT 250 WORDS)

Axons↗

PubMed1994

[Encephalomyelitis with cavitary necrosis of the white matter. A clinico-pathologic study].

The authors report the clinico-pathological study of an encephalomyelitis with necrotic cavitation of the white matter occurring in a 61-year-old female. The disease of sudden onset progressed slowly to the death, 20 months after the onset of the first symptoms. They stress the rarity of the entity and the difficulties to establish the diagnosis clinically. The nosological situation of the condition is discussed and compared with the previously reported cases.

Brain↗

PubMed1993

[Early infantile epileptic encephalopathy (Ohtahara syndrome) with poly-microgyria].

A boy, born after normal pregnancy and delivery, began to have fits at 3 days. The seizures were composed of tonic or tonic-clonic convulsions at the upper extremities but myoclonus was absent. These attacks were not easy to control. There was gross developmental delay. Laboratory investigations were almost normal except for cerebrospinal fluid: pleocytosis and high protein content. EEG showed "suppression-burst" and MRI revealed high signal intensity in the left temporo-occipital region on T2 weighted image. At three and a half months of age, EEG changed into hypsarrhythmia. The child died at 5 months of age. At post mortem neuropathological examination, the cortical ribbon in the bilateral parieto-occipital regions appeared thick, as if there were pachygyria. Microscopically polymicrogyria was noted in these areas as well as in the insular cortex. This lesion showed a symmetrical distribution. The cytoarchitectonic features of the polymicrogyric cortex did not consist of 4 layers. The other structures of the central nervous system were almost devoid of lesion. The number of clinico-pathological reports on Ohtahara's syndrome is very limited and the etiopathogenesis of polymicrogyria is discussed.

Brain↗

PubMed1991

[Prolonged traumatic coma caused by diffuse axonal lesions].

A 22-year old male patient was admitted for deep coma probably of traumatic origin. There was neither fracture of the skull nor expansive intracranial lesion. The patient survived for 6 years and 8 months without any change in consciousness. Post-mortem neuropathological examination showed lesions which predominated in the white matter and had features that were compatible with diffuse axonal injury. The mechanism responsible for these lesions seems to be stretching and shearing of axones at the moment of impact. The exceptionally long duration of survival probably accounts for the severity of the lesions observed.

Adult↗

PubMed1991

[Diffuse axonal injury (DAI) in an autopsy case of head trauma with long survival].

The authors reported a clinico-pathological case survived 11 months after a traffic accident. A 41-year-old man had been hit by a motor car and was found in a state of semicoma. On admission, his consciousness level was III-100 to 200 (Japan Coma Scale). Pupils were isocoric; light reflex was present. Linear fracture of occipital bone was disclosed by Skull X-ray and subarachnoid hemorrhage was revealed on CT scan. This comatose state, lasting 24 hours, slowly improved and eventually he presented the so-called Korsakoff's syndrome until his death. He could not recognized his relatives, only uttered some meaningless words. He was unable to obey simple verbal orders. The patient was incontinent and right pyramidal sign was positive. On repeated CT scans, cerebral ventricles gradually increased in size; especially the enlargement of the fourth ventricle was remarkable. He expired of septic shock caused by bed sores. At autopsy brain weighed 1190 g. Old gloss contusional scars were observed on the bilateral frontal lobes including the orbital area and on the left temporal pole. Gliding contusions were revealed in the subcortical white matter beneath the left superior frontal convolution. Fibrillary gliosis was noted in this region, the deep white matter underlying the left temporal pole and the tissue surrounding the anterior horn of the left lateral ventricle. Nerve fibers were fragmented and lacerated at corpus callosum, anterior commissure and posterior limb of the left internal capsule. Bilateral pyramidal tracts showed mild myelin pallor at the brainstem. Loss of Purkinje cells were observed. This case would correspond to mile type of diffuse axonal injury proposed by Adams and Gennarelli. (ABSTRACT TRUNCATED AT 250 WORDS)

Accidents, Traffic↗

PubMedDate not supplied

[Dementia and amyotrophy in Kufs disease. The adult type of neuronal ceroid lipofuscinosis].

A 26-year-old housewife, born of consanguineous parentage, began to have gait and speech disturbance. Her brother had died from suffocation because of dysphagia. At thirty-two, she developed difficulty in swallowing, clumsiness and incontinence. When she was thirty-six she had pseudobulbar palsy, vertical gaze paresis, hyperreflexia and muscular atrophy of the upper half of the body. CT scan showed cerebral atrophy. Her mental function progressively deteriorated and amyotrophic lateral sclerosis associated with dementia was suspected. She died at the age of thirty-seven. Diagnosis was made only by autopsy. There was no particular general pathologic finding excepting aspiration pneumonia. Microscopical examination revealed numerous distended neurons with accumulation of light brown pigments by Luxol fast blue/H & E stains, especially in hypothalamus, substantia nigra and nuclei of oculomotor nerves. To a lesser extent such neurons were noted ubiquitously. The stored material was mainly composed of lipofuscin and ceroid. Ultrastructurally they presented the various structures which have previously been reported, except for finger print profiles. The pigmentary deposits were shown to be immunoreactive with polyclonal antibody directed against amyloid beta-protein.

Adult↗

PubMedDate not supplied

[Cytomegalovirus fetal infection. Porencephaly with polymicrogyria in a 15-year-old boy].

A boy, born after 41 weeks of gestation, presented with splenomegaly, microcephaly and chorioretinitis accompanied by immaturity signs. His mother was in good health but her previous pregnancy had been aborted owing to rubella. Laboratory data, including serological and virological evidence, confirmed the diagnosis of fetal cytomegalovirus infection. CT scan indicated a large cyst in the left temporal lobe and periventricular calcifications. At about 8 months of age, convulsions were noticed which were not controlled effectively by medication. There was spastic rigidity without significant psychomotor development. He died at the age of 15. Postmortem neuropathological examination revealed polymicrogyria predominant in the right cerebral hemisphere as well as a large cavity in the left temporal lobe communicating with the lateral ventricle. Widespread heterotopias and calcifications were observed notably in the periventricular white matter. No typical inclusion was found. By the method of Holzer and GFAP immunocytochemistry, no gliosis was noted in the cerebral cortex having the feature of polymicrogyria. This might support the theory that polymicrogyria is caused by neuronal migration failure.

Adolescent↗