Biomedical subjects

T Akimura

Publications and source records attributed to T Akimura.

24 records · Page 2Linked to original sources

PubMed1989

Cerebral endothelial regeneration following experimental brain injury. Variation in the regeneration process according to the severity of injury.

It is still unknown when and in which area endothelial regeneration occurs after brain injury, and to what extent such changes depend on the severity of the injury. We have, therefore, studied bromodeoxyuridine (BrdU) uptake by regenerating endothelial cells in two different groups of rats given cold lesions using immunohistochemistry employing anti-BrdU monoclonal antibody, anti-factor VIII-related antigen antibody and anti-glial fibrillary acidic protein antibody. The earliest evidence for the presence of BrdU-positive endothelial cells (BrdU + end) was observed at 2 days after injury, the injured endothelial cells regenerating from the edge toward the center of the lesion in both groups. We considered that edema fluid could act as an important factor, since at 2 days post-injury BrdU + end were not in contact with macrophages and were always found in Evans blue-stained areas. Study of endothelial cell kinetics also confirmed that the repair of injured endothelial cells was intimately involved in the reconstruction of the blood-brain barrier, since the time of disappearance of BrdU + end coincided with the disappearance of Evans blue-stained areas. The difference in the process of endothelial regeneration was first apparent on the 3rd day, there being no difference at 2 days.

Animals↗

PubMed1989

Infrasellar craniopharyngioma.

A rare case of infrasellar craniopharyngioma mainly occupying the paranasal sinuses, the infratemporal fossa and the skull base is presented. The patient had been treated by an otolaryngologist as a case of mucocele of the sphenoid and ethmoid sinuses because the biopsy specimens obtained at endonasal surgery failed to confirm the true diagnosis. Computed tomography (CT) showed multi-lobulated low density cysts in the paranasal sinuses, infratemporal fossa and skull base, and the cyst wall was enhanced. Magnetic resonance Imaging (MRI) revealed the cysts to have high intensity in both T1- and T2-weighted images, and excellent three-dimensional visualization was obtained. Characteristic motor-oil-like fluid was aspirated during transnasal surgery and the diagnosis of craniopharyngioma was confirmed by histological examination.

Child↗

PubMed1989

Multiple meningiomas of the spinal canal and posterior fossa--case report.

The majority of multiple meningiomas are associated with von Recklinghausen's disease, and those that are not, i.e., true multiple meningiomas, particularly with simultaneous development in the posterior fossa and spinal canal, are very rare. We recently encountered a case of true multiple meningiomas in which the lesions were found simultaneously in the left posterior fossa and the upper thoracic spinal canal. The spinal meningioma consisted mainly of meningotheliomatous components, and that in the posterior fossa of fibroblastic components. Both tumors were surgically removed. The cause of the multiplicity in cases of true multiple meningiomas is unknown. Incidental multiplicity is a consideration when the number of tumors is relatively small. Spinal meningiomas are often undetected in the absence of neurological symptoms. However, even if von Recklinghausen's disease is not present, and particularly when more than two meningiomas have been discovered, the patient must be carefully examined for other tumors.

Aged↗

PubMed1989

[Cerebral sparganosis mansoni--report of two cases].

Cerebral Sparganosis Mansoni is a very rare disease caused by a larva of Diphyllobothrium and so far, only two cases have been reported. Another two cases are presented in this paper. Case 1: A 64-year-old man was admitted presenting with hypovolition. He has eaten thunder fishes several years before. CT scan revealed an extensive low density area with an enhanced nodular mass around the right basal ganglia. An operation was carried out on the preoperative diagnosis of brain tumor and a granuloma was completely removed. His postoperative course was excellent. The histological examination confirmed the diagnosis of cerebral sparganosis. Case 2: The patients was 60-year-old male showing hypesthesia in the left half of his face. He has often been to South Korea where patients of Sparganosis Mansoni are often reported. Enhanced CT scan demonstrated a small nodular region in the tip of the left temporal lobe. Sparganum Mansoni was identified during surgery and a granuloma was also extirpated. His postoperative course was also excellent. In cases with cerebral parasitism by Sparganum Mansoni, CT scan shows an extensive low density area with a nodular enhancement, but no calcification nor cyst formation. It is quite difficult to differentiate sparganosis from cerebral tumors on CT and laboratory data preoperatively. The diagnosis is usually confirmed by postoperative histological examination. As for the treatment of this disease, no effective chemotherapy is now available and surgical excision is recommended. Actually, four cases with cerebral sparganosis including two of our own demonstrated a satisfactory prognosis by surgical treatments.

Animals↗

PubMedDate not supplied

Meningioma with extensive vacuolization--a contribution to the pathogenesis of intratumoral cyst formation.

Seven cases of meningioma with extensive vacuolization are reported. Upon plain CT, two cases appeared as diffuse hypodense masses, while two cases were mixed-density masses consisting of iso-dense and low-density components. A diffuse marked enhancement effect was seen in three cases and a thin ring enhancement effect appeared in one case. In four of these cases, macroscopic cysts were observed. It is suggested that the formation of macroscopic cysts or microscopic vacuoles mimics the developmental process of the subarachnoid space in the embryo. A review of the literature on this phenomenon is presented.

Adult↗

PubMedDate not supplied

Measurement of labeling index of DNA polymerase alpha in human brain tumors. Comparative study with labeling indices of BUdR in vitro and Ki-67.

Proliferative activity of 28 human brain tumors was estimated by simultaneous measurement of DNA polymerase alpha, Ki-67 and bromodeoxyuridine (BUdR) labeling indices on microscopic tissue preparations stained immunologically with monoclonal antibodies using a peroxidase technique. All the antigens were exclusively found in the nucleus. The labeling index of BUdR was lower than those of the other indicators. The values of the DNA polymerase alpha labeling index were almost the same as those of the Ki-67 labeling index. Simultaneous measurement of these parameters may provide more useful information on tumor cell growth kinetics than that of a single parameter.

Adolescent↗