H. Chigasaki

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Hyperbaric oxygen (HBO; 100% oxygen at 2 atmospheres absolute) was administered for 1 h to male Mongolian gerbils either for a single session or every other day for five sessions. Two days after HBO pretreatment, the gerbils were subjected to 5 min of forebrain ischemia by occlusion of both common carotid arteries under anesthesia. Seven days after(More)
Increased neuronal vulnerability to ischemia or hypoxia has been demonstrated following traumatic brain injury but not explained. Animal data suggest that neuronal damage after traumatic brain injury is caused mainly by massive glutamate release that activates N-methyl-D-aspartate (NMDA) receptors. Using rat models with controlled closed head injury (CHI)(More)
BACKGROUND The purpose of this study was to clarify the pathologic features and clinical significance of the meningeal enhancement surrounding meningiomas ("flare sign") on contrast-enhanced T1-weighted magnetic resonance images (MRI). METHODS The marginal dura mater of tumors was resected from nine cases of meningioma exhibiting a flare sign and used for(More)
Immunohistochemical staining for microtubule-associated protein 2 (MAP2) and synaptophysin was used to investigate the effect of hypoxia on hippocampal neurons after mild concussion in the rat. Male Sprague-Dawley rats were divided into four groups: Group 1 (n = 3) was subjected to a mild impact-acceleration closed head injury, group 2 (n = 3) was subjected(More)
Changes in cerebrovascular dynamics were investigated immediately after closed head injury in the rat using a newly developed closed head injury model developed by Marmarou et al. Intracranial pressure (ICP) and mean arterial blood pressure (MABP) were monitored before and after trauma. Regional cerebral blood flow (rCBF), regional cerebral plasma volume(More)
Delayed neuronal damage in the ischemic region of the rat brain following middle cerebral artery (MCA) occlusion in stroke-prone spontaneously hypertensive rats was studied. The distribution of neuronal damage was determined by 45Ca autoradiography. Accumulation of 45Ca was observed in the corpus callosum and ipsilateral cerebral cortex immediately(More)
A cooperative study was made of 4750 intracranial aneurysm cases collected from 133 neurosurgical clinics in Japan by letter inquiry for the period of 2 years from January 1974 to December 1975. Among them, 4124 cases (87%) had a single aneurysm, and 626 cases (13%) had multiple ones. Direct radical surgery was done in 78% of all cases, carotid ligation in(More)