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Biomedical subjects

H Namba

Publications and source records attributed to H Namba.

At least 235 records · Page 13Linked to original sources

Changes of hippocampal glucose utilization subsequent to amygdaloid-kindled generalized seizures.

Local changes in cerebral glucose utilization during the postictal phase of amygdaloid-kindled generalized seizures were studied with the quantitative autoradiographic 2-[14C]deoxyglucose method in conscious rats. Measurement was initiated either just after termination of a behavioral seizure (GS-I) or 30 s after seizure termination (GS-II) to determine dynamic metabolic changes in the postictal phase. Although glucose utilization of the neocortex was remarkably depressed in both GS-I and GS-II, that of the hippocampus significantly increased in GS-I and then decreased in GS-II as compared with control. These changes of hippocampal glucose utilization were observed in all sectors of the pyramidal cell layer (CA 1-4) and in the molecular layer. Because metabolic changes associated with development of amygdaloid-kindled seizures begin in the limbic structures including the hippocampus, the transient increase in hippocampal glucose utilization observed in the early postictal phase indicates that the hippocampus is one of the key structures not only for initiating and maintaining but also for terminating kindled seizures.

Amygdala↗

Echocardiographic and Doppler diagnosis: first case of atrial septal aneurysm in a cat.

A 6-year-old female cat developed pleural and abdominal effusion. Cardiac ultrasound and 2D color tissue Doppler imaging revealed restrictive cardiomyopathy with severe biatrial dilatation and hypertension. This cardiomyopathy was associated with atrial septal aneurysm and a patent foramen ovale. The atrial septal aneurysm involved the entire atrial septum. Necropsy and histological examination confirmed all these findings. ASA is a rare malformation and, as in this cat, it generally occurs concomitantly with congenital or acquired heart disease and may be explained by greater pressure in one atrium, leading to controlateral protrusion of the atrial septum.

Animals↗

Induction of acquired immunity in rats that have eliminated intracranial gliosarcoma cells by the expression of herpes simplex virus-thymidine kinase gene and ganciclovir administration.

We examined a possible antitumor response against 9L rat gliosarcoma cells induced by the expression of the herpes simplex virus-thymidine kinase (HSV-TK) gene and the ganciclovir (GCV) system. Based on the amount of the major histocompatibility complex (MHC) class I antigens expressed on 9L cells transduced by the HSV-TK gene (9L/HSV-TK) we selected two clones (clones H and L), which represent high and low expressors of class I antigens, respectively. By means of serial magnetic resonance imaging we followed the change of tumor volumes of each clone in syngeneic rats, and found that the intracranial tumor growth was inversely correlated with the expression of MHC class I antigens, although in vitro growths of the clones remained unchanged. Moreover, histological examination revealed significant lymphocyte infiltration in the 9L/HSV-TK tumor of high MHC expression but not in the wild-type tumor. The therapeutic effect of GCV on them was not different, but we observed a prolonged survival of the rats which had eliminated 9L/HSV-TK clone L tumors by the treatment of GCV and were rechallenged with the same cells compared with the survival of naive rats inoculated with clone L cells. These data collectively suggest that the immune response operates even in the brain previously described as an immunologically privileged site.

Animals↗

Cdc6 expression as a marker of proliferative activity in brain tumors.

Antibodies against human proteins that regulate DNA replication such as Cdc6 and Mcm5 became available as a new marker of proliferation. We performed immunohistochemical analysis with MIB-1 and antibody against Cdc6 on 35 brain tumors, including tumors of neuroepithelial tissue, vestibular schwannomas, meningiomas, and pituitary adenomas. Median reactivity for MIB-1 was 8.8%, and that for Cdc6 was 55%. Reactivity in most brain tumors was significantly higher for Cdc6 than for MIB-1, but reactivity of Cdc6 was independent of tumor grade. Detection of Cdc6 expression might be useful for the estimation of proliferative activity in brain tumors.

Antigens, Nuclear↗

Significance of surgical resection for the treatment of multiple brain metastases.

BACKGROUND: We investigated the role of surgery in the treatment of multiple brain metastases when performed with radiation therapy. PATIENTS AND METHODS: One hundred and thirty-eight patients who underwent resection for brain metastases and received 30 Gy or more of adjuvant radiation therapy were entered into this study. Seventy-seven of the 138 patients (56%) had single brain metastases (Single Group), while the remaining 61 patients (44%) had multiple foci (Multiple Group). The 138 patients were divided into four subgroups; patients in Single Group treated with total or subtotal resection (Group A), those in Multiple Group who underwent total or subtotal resection and had remaining tumors smaller than 2 cm (Group B), those in Single Group treated with partial resection (Group C), and the other patients in Multiple Group (Group D). RESULTS: The median survival was 8.7 and 9.2 months for the Single Group and the Multiple Group, respectively (not statistically different). The median survival was 9.6, 12.4, 3.7, and 4.5 months for Groups A, B, C, and D, respectively. Survival duration differed significantly between Groups A/B and Groups C/D (p < 0.05). CONCLUSIONS: Surgical reduction of tumor volume which is approximately larger than 2 cm improves the efficacy of adjuvant radiation therapy and contributes to survival even in the patients with multiple brain metastases.

Adult↗