Biomedical subjects

J Ito

Publications and source records attributed to J Ito.

525 records · Page 30Linked to original sources

PubMedDate not supplied

Event-related potentials (ERPs) associated with omitted somatosensory stimuli.

Late positive ERP components elicited by omitted somatosensory stimuli in passive paradigm (passive MSPP) and in active time-estimation paradigm (active MSPP) were studied in healthy subjects with single-trial analysis and conventional averages. The active MSPP was also compared with P3 component elicited by somatosensory target stimuli (target P3). Single-trial analysis showed clearly discernible passive MSPP in response to omitted stimuli of the median nerve, whereas passive MSPP was hardly detected in response to omitted stimuli of the index finger. The subjects might pay passive attention to absence of somatosensory stimuli together with absence of the thumb muscle twitches. Single-trial analysis revealed a significantly greater latency fluctuation in passive MSPP than in active MSPP. The active MSPP showed a greater latency fluctuation than the target P3. The active MSPP showed a significantly longer latency and a smaller amplitude than the target P3 in conventional averages. Topography of active MSPP showed a symmetric central-parietal maximal distribution similar to that of target P3.

Adult↗

PubMedDate not supplied

Early ultrastructural changes in the dorsal mucosa of rat tongue after irradiation, with special reference to the microvasculature.

PURPOSE: To clarify the acute effects of irradiation on the ultrastructural conformation of the dorsal mucosa of the rat tongue, with special reference to the changes in microvasculature. METHODS: The proboscis of seventy rats were irradiated. The animals were then perfusion-fixed, followed by India ink-injection or resin casting at 3 to 7 days after irradiation. The bulk, frozen sections, or plastic embedded sections of the treated rat tongues were examined by light and electron microscopy. RESULTS: In the dorsal epithelium of the rat tongue, multi-nucleated cells appeared in the basal layer at 3 days after irradiation. At day 5, the thickness of the epithelial layer and connective tissue papillae decreased dramatically, concomitant with the shortening of the capillary loops. At day 7, lingual papillae and connective tissue papillae disappeared, leaving dissociated epithelial cells and numerous neutrophils migrating throughout the tissue. Subepithelial blood vessels displayed drastic dilation with a number of neutrophils adhering to the endothelial surface, but without ultrastructural abnormalities in its cellular components. CONCLUSION: Early changes in the dorsal mucosa of the irradiated rat tongue were limited to the basal epithelial cells, leading to a total disruption of the epithelial layer. Atrophic changes of the capillary loops is due to the loss of the connective tissue papillae. Dilation and conformational changes of the subepithelial capillaries appear to result from the inflammatory reaction, taking place secondarily to the loss of the epithelial barrier of the irradiated tongue. A difference in radiosensitivity among the epithelial, endothelial, and mesenchymal cell components of the rat tongue in vivo is suggested.

Animals↗

PubMedDate not supplied

Primary central nervous system lymphoma presenting as diffuse cerebral infiltration.

We report a case of primary central nervous system lymphoma presenting as diffuse cerebral infiltration. On T2-weighted spin echo MR imaging using a 1.0 Tesla unit, high signal intensity lesions were presented mainly in the bilateral pyramidal tracts and also diffusely extended to white matter with brain swelling. No enhancing lesion was demonstrated after the intravenous injection of Gadolinium-DTPA, during the course of her disease. Radiological diagnosis of gliomatosis cerebri was made because of the characteristic MR appearance. Stereotactic biopsy was performed, and diffusely scattered lymphocytes, probably neoplastic, in the cerebral white matter were demonstrated histopathologically. Oral corticosteroids, radiation therapy, and chemotherapy were applied soon after her admission. The patient's condition improved dramatically. MR imaging using a 1.5 Tesla unit after the treatments showed marked regression and reduction of high intensity lesions on T2-weighted images and improvement of brain swelling. It should be emphasized that brain biopsy is important method for correct diagnosis in case of diffuse non-enhancing brain lesions like our case.

Biopsy↗