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Biomedical subjects

T Orita

Publications and source records attributed to T Orita.

At least 73 records · Page 4Linked to original sources
PubMed1990

Subependymal giant cell astrocytoma associated with tuberous sclerosis: with special reference to cell kinetic studies--case report.

The authors report a case of subependymal giant cell astrocytoma associated with tuberous sclerosis in a 15-year-old boy. Computed tomographic scans showed a large intraventricular mass with peritumoral calcification and a cyst in the left lateral ventricle. Left dominant unilateral hydrocephalus was also revealed. Magnetic resonance images clearly demonstrated the lesion. The tumor was subtotally removed and a ventriculoperitoneal shunt was performed because of the hydrocephalus. The proliferation potential was assessed by measuring the bromodeoxyuridine (BUdR) labeling index employing the in vitro labeling method, and determining the deoxyribonucleic acid (DNA) content by flowcytometry. BUdR-positive cells were found to be rare, and the DNA histogram demonstrated no evidence of high proliferative activity or aneuploidy.

Adolescent↗
PubMed1990

Silver colloid staining technique for analysis of glioma malignancy.

A silver colloid staining technique for identifying nucleolar organizer region-associated proteins (Ag-NOR's) was applied to 51 human gliomas. These comprised 20 glioblastomas multiforme, 15 anaplastic astrocytomas, and 16 astrocytomas, in which the mean numbers of Ag-NOR's per cell (+/- standard error of the mean) were 2.51 +/- 0.12, 2.01 +/- 0.10, and 1.76 +/- 0.06, respectively. Significant differences among these were recognized, and the mean number of Ag-NOR's paralleled the degree of histopathological malignancy. In 16 cases, studies were performed of the number of Ag-NOR's and the S-phase fraction by in vitro labeling using antibromodeoxyuridine monoclonal antibody. A linear relationship was demonstrated between these two factors (r = 0.857, p less than 0.001), although some scatter was seen. In 32 adult patients, the correlation between the number of Ag-NOR's and the prognosis was estimated. The results demonstrated that the group containing patients with less than 1.80 Ag-NOR's per cell had a better prognosis than the group with 1.80 Ag-NOR's or more. Thus, the number of Ag-NOR's reflected the degree of histopathological malignancy, S-phase fraction, and prognosis. Silver colloid staining for Ag-NOR's is a simple, rapid, and reproducible method for estimating the proliferative potential of human gliomas without requiring a complicated technique.

Astrocytoma↗
PubMed1990

Correlation of in vitro bromodeoxyuridine labeling index and DNA aneuploidy with survival or recurrence in brain-tumor patients.

There are no previous reports correlating the in vitro bromodeoxyuridine (BUdR) labeling index (LI) with the clinical outcome in patients with brain tumors. The reliability of the LI as a predictor of patient survival or recurrence was examined in this study of 66 human brain tumors (19 gliomas, 18 meningiomas, and 29 others). Anti-BUdR staining was performed on surgically extirpated tumor tissue that had been treated with BUdR as previously described. Correlation of the BUdR LI with patient survival or tumor recurrence rate was carried out by the method of Kaplan and Meier. Deoxyribonucleic acid (DNA) aneuploidy was estimated in 52 cases. The results of this study indicate that BUdR LI values correlated well with the clinical course of patients with brain tumor. In comparison with patients with higher LI's, there was both a significantly higher survival rate for tumors other than meningiomas and a higher recurrence-free rate for meningiomas in patients with LI's of less than 4% and 1%, respectively. Although there was a tendency for patients without tumor aneuploidy to show better survival data than the others, no statistical difference was observed. These results suggest that the in vitro BUdR labeling method is reliable for prediction of a patient's prognosis, whereas prognosis on the basis of DNA aneuploidy alone is uncertain.

Adolescent↗
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

Extradural nasal and orbital extension of malignant glioma. Case report.

A rare case of extradural nasal and orbital extension of malignant glioma is presented. The development of malignant changes was observed during 10 years. The mode of transdural extension was via the olfactory nerve, where it was directly destructive in all four cases that have been reported to date. The biological malignancy of transdurally extending glioma is also described.

Adult↗
PubMed1989

[Coagulation and fibrinolysis in chronic subdural hematoma. Measurement of fibrinopeptides].

The pathogenesis of chronic subdural hematoma is not fully understood. It is thought that fibrinolytic hyperactivity within the hematoma capsule plays an important role. However, since this hyperactivity has not been found in the systemic blood, accelerated fibrinolysis is thought to occur only locally. To evaluate coagulant and fibrinolytic activities in the peripheral blood, the authors measured fibrinopeptide A (FPA) and fibrinopeptide B beta 15-42 (FPB beta), which are relatively sensitive hematologic factors, in 14 patients with chronic subdural hematoma. Peripheral venous blood was collected within 24 hours before surgery and FPA and FPB beta levels were determined. In the eight cases followed for more than 1 month after surgery, pre- and postoperative FPA and FPB beta values were compared. The possible relationship between preoperative FPB beta and hematoma density as well as elevated intracranial pressure (judged by preoperative computed tomography) was also examined. The following results were obtained: 1) Preoperative FPA and FPB beta values were both statistically significantly elevated suggesting systemic acceleration of coagulant and fibrinolytic activities. FPB beta levels exceeded those of FPA in almost all cases, indicating that fibrinolysis was more dramatically enhanced. 2) Many patients with high FPB beta values had high-density areas on computed tomography scans. 3) Patients with choked disc had high FPB beta values, suggesting a correlation between chronic intracranial hypertension and FPB beta. 4) Postoperatively, there was a marked decrease in FPA values, whereas FPB beta values remained above normal, which may reflect persistence of accelerated systemic fibrinolytic activity in patients with chronic subdural hematoma.

Adult↗
PubMed1989

Flow-cytometric DNA analysis and immunohistochemical measurement of Ki-67 and BUdR labeling indices in human brain tumors.

Cell proliferation potential was assessed by measuring the labeling indices of the monoclonal antibody Ki-67 and of 5-bromodeoxyuridine (BUdR), and the cellular deoxyribonucleic acid (DNA) content in 48 human brain tumors. The diagnostic and prognostic value of flow-cytometric DNA analysis was also evaluated using ethanol-fixed paraffin-embedded BUdR-labeled specimens; these were the same specimens as were used for measuring the BUdR and Ki-67 labeling indices. Both the Ki-67 and the BUdR labeling indices correlated with the degree of malignancy estimated from conventional histological preparations. The Ki-67 labeling index was 1.7 times greater than the BUdR labeling index. The relationship of DNA aneuploidy to the labeling indices or to morphology in cases of glioma was examined. All of the tumors with an aneuploid line corresponded to malignant glioma classified by histological criteria, although malignant glioma did not always show DNA aneuploidy. In addition, the cases with aneuploid lines showed high BUdR and Ki-67 labeling indices. The cell kinetic data, which indicate the biological character of tumors, allowed prediction of the prognosis of the patients with gliomas. In contrast, despite the presence of an aneuploid line, three of 13 meningiomas showed a benign histological pattern without an aggressive clinical course, and neither the Ki-67 nor the BUdR labeling index was high. These results indicate an unequivocal relationship between DNA aneuploidy and clinical behavior; in general, both labeling indices may prove to be objective indicators of the outcome of patients with brain tumors.

Aneuploidy↗
PubMed1988

Control of cell division by sex factor F in Escherichia coli. III. Participation of the groES (mopB) gene of the host bacteria.

Cell division of F+ bacteria is coupled to DNA replication of the F plasmid. Two plasmid coded genes, letA (ccdA) and letD (ccdB) are indispensable for this coupling. To investigate bacterial genes that participate in this coupling, we attempted to identify the target of the division inhibitor (the letD gene product) of the F plasmid. Two temperature-sensitive growth defective mutants were screened from bacterial mutants that escaped the letD product growth inhibition that occurs in hosts carrying an FletA mutant. Phage P1-mediated transduction and complementation analysis indicated that the temperature-sensitive mutations are located in the groES (mopB) gene, which is essential for the morphogenesis of several bacteriophages and also for growth of the bacteria. The nucleotide sequence of the promoter region of the gene in which the temperature-sensitive mutations had occurred was virtually identical with that of the groES gene of Escherichia coli; furthermore the sequence of the first five amino acid residues and the overall amino acid composition predicted from the nucleotide sequence of the gene match those of the purified GroES protein. The temperature-sensitive mutants did not allow the propagation of phage lambda at 28 degrees C and formed long filamentous structures without septa at 41 degrees C, as is observed in the case of groES mutants. Growth of the two groES mutants tested was not inhibited by the F plasmid with the letA mutation. These observations suggest to us that the morphogenesis gene groES plays a key role in coupling between replication of the F plasmid and cell division of the host cells.

Bacterial Proteins↗
PubMed1988

The microvascular architecture of human malignant glioma. A scanning electron microscopic study of a vascular cast.

The three-dimensional microvascular architecture of human glioma was investigated. The results of the study, the first of its kind, suggested that the process of vascularization in glioma is based on two patterns. In a large proportion of the glioma, one pattern is similar to the vascularization observed in normal developing fetal and newborn rat brain, while in a small proportion of the glioma, another pattern including complicated vascular protrusion and spiral running, is seen.

Brain Neoplasms↗
PubMed1988

Bilateral intracranial fibrous xanthoma.

We present a case of fibrous xanthoma in a 6-year-old boy who showed disturbance of consciousness and signs of increased intracranial pressure. A computed tomographic (CT) scan showed bitemporal enhanced masses and hydrocephalus. The patient was operated on in two stages. The tumors were located intradurally and extracerebrally and were firmly attached to the dura mater at the base of the middle fossa. Glial fibrillary acidic protein stain was negative, and histologic examination suggested a diagnosis of bilateral fibrous xanthoma. Postoperative CT scan showed residual tumors and an enlarged choroid plexus adjacent to it. A CT scan at 12 years of age showed no enhanced tumor, but disclosed bitemporal high-density areas and diffuse brain atrophy; the choroid plexus reverted to normal size. The patient showed mental and physical retardation, perhaps owing to the compression of the hypothalamus during early childhood. This would appear to be the first known case of bilateral intracranial fibrous xanthoma.

Brain Neoplasms↗
PubMed1988

Cerebral microvascular architecture following experimental cold injury.

The sequential changes in microvascular architecture following local cold injury in rat brains were studied post mortem by scanning electron microscopy and the vascular casting method. The findings were compared with the results of immunohistochemical studies of injured endothelial cells using the bromodeoxyuridine (BUdR) and anti-BUdR monoclonal antibody technique. Repair of the microvascular architecture had begun by the 3rd day after injury, with hematogenous cells and reactive astrocytes present in the edematous brain participating in the regenerative process. The normal microvascular architecture was reconstructed starting from the edge of the lesion nearest to the brain surface. On the other hand, in the most severely injured part of the brain surface, newly formed microvascular architecture appeared, resembling that of the developing fetal and newborn rat cortex. Seven days after injury, the entire microvascular architecture in the region of the lesion had been reconstructed.

Animals↗
PubMed1988

Cell kinetics studies of human brain tumors by in vitro labeling using anti-BUdR monoclonal antibody.

Since the development of a specific monoclonal antibody against the thymidine analogue bromodeoxyuridine (BUdR), many investigators have used intravenous infusion of BUdR to estimate the proliferative potential of human brain tumors. However, side effects such as the induction of cell mutation, latent virus promotion, or inhibition of cytodifferentiation cannot be ignored, and thus many workers hesitate to use it in patients, especially those with hepatic disease or of reproductive age. Furthermore, if BUdR remains in the deoxyribonucleic acid of tumor cells after injection, analysis of the effect of chemical and radiation therapy may not be evaluated correctly. In this report, in vitro BUdR labeling with an anti-BUdR antibody is compared with the in vivo methods described by previous authors. This method appears to be useful for determining the S-phase fraction of human brain tumor. It was more rapid, and was simple, safe, and reproducible as compared to the intravenous infusion method.

Antibodies, Monoclonal↗
PubMed1988

[A case of hemorrhage into a brain abscess].

A rare case of hemorrhage into a brain abscess in a 23-year-old man is reported. The patient complained of headache and low-grade fever on February 26, 1986. Two days later, he developed right hemiparesis and right hemisensory disturbance with mild consciousness disturbance and was admitted to a local hospital. Seven days after the onset, he suddenly became semicomatose, developed anisocoria and was consequently transferred to the University Hospital. On admission, his temperature was 37.5 degrees C and neurological examination revealed semicoma, anisocoria and right hemiparesis without nuchal rigidity. Enhanced CT scan showed a high density area within an irregular ring enhancement at the left basal ganglia. At that time, malignant glioma was diagnosed and an emergency operation was performed by left frontotemporal craniectomy. During the operation blood clot was found in the posterior part of the basal ganglia. After operation, a histological examination was made and a brain abscess was diagnosed. Gram staining revealed gram-positive bacillus. By aspiration of the abscess and chemotherapy, recovery was gradually made. He was discharged with motor dysphasia and mild right hemiparesis three months later. Differentiation between abscess and malignant glioma and the cause of the hemorrhage are discussed.

Adult↗