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T Kamiryo

Publications and source records attributed to T Kamiryo.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Brain tumors in Yamaguchi Prefecture--incidence through 4 years].

The incidence of brain tumors was studied in Yamaguchi prefecture of about 1,600,000 population. All of the brain tumor patients admitted to the neurosurgical hospitals in Yamaguchi prefecture were registered. Cases of osteoma, lipoma, scalp tumor and spinal tumor were excluded. From 1986 through 1989, 726 cases were registered. 135 recurrent cases were included. Therefore first-diagnosed primary brain tumors were selected to calculate the true incidence. The number of cases of primary brain tumor was 478 and showed female preponderance (male/female: 207/271). The incidence of primary brain tumor was 7.5/100,000/year (male/female: 6.8/8. 1). No difference was present between the incidence in cities and that in rural districts. Percentages of representative tumors were 28.2% for glioma, 32.8% for meningioma, 13.0% for pituitary adenoma and 10.7% for neurinoma. Age-adjusted incidence was 2.1/100,000/year for glioma and 2.1/100,000/year for meningioma. The incidence of glioma was lower and that of meningioma was higher in Yamaguchi prefecture than those in other reports. Compared with the Brain Tumor Registry of Japan (1969-1983), the percentage of meningioma cases was large in Yamaguchi prefecture. This difference owed partly to the increased number of population over age of 40's in Yamaguchi prefecture. The peak of age distribution was present in age of 50's in Yamaguchi prefecture and in age of 30's and 40's in Brain Tumor Registry of Japan. The peak of age distribution shifted to older ages in Yamaguchi and the difference was conspicuous in age of 60's. This peak consisted of mainly cases of meningioma and partly those of glioma.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1990

A novel peroxisomal nonspecific lipid-transfer protein from Candida tropicalis. Gene structure, purification and possible role in beta-oxidation.

We have sequenced the nucleotides of the gene POX18 that encodes PXP-18, a major peroxisomal polypeptide inducible by oleic acid in the yeast Candida tropicalis. POX18 had a single open reading frame of 127 amino acids. Some 33% of the amino acid sequence of the predicted basic polypeptide (13,805 Da), was identical to that of the nonspecific lipid-transfer protein (sterol carrier protein 2) from rat liver. PXP-18, purified to near homogeneity from isolated peroxisomes, had an amino-terminal sequence identical to that of the predicted polypeptide except for the initiator methionine, and had nonspecific lipid-transfer activity comparable to that of its mammalian equivalents. Unexpectedly, PXP-18 lacked the cysteine residue thought to be essential for the activity of this protein in mammals. RNA blot analysis showed that the POX18 gene was expressed exclusively in cells grown on oleic acid, suggesting that PXP-18 has a role in the beta-oxidation of long-chain fatty acids. PXP-18 modulated acyl-coenzyme A oxidase activity at low pH.

Amino Acid Sequence↗
PubMed1990

Development of the rat meninx: experimental study using bromodeoxyuridine.

The development of the rat meninx from the viewpoint of cell proliferation was studied microscopically and immunohistochemically using bromodeoxyuridine (BUdR). A compact cell layer around the neural tube, the meninx primitiva, was observed in 12- and 13-day fetuses. A reticular structure resembling the subarachnoid space appeared in the 14-day fetus. The ectomeninx, consisting of a collagen fiber layer, part of which became the dura mater, appeared in 15-day fetuses, allowing discrimination of the endomeninx, the arachnoid cell layer. The primordium of the choroid plexus also appeared in the lateral ventricle on the same day. Bone appeared in the primitive dura mater, and stratification of the meninx was almost complete in 21-day fetuses. BUdR-positive cells were confirmed in the meninx from day 12 of gestation to day 15 postpartum. The number of BUdR-positive cells was greatest in fetuses aged about 12 or 13 days, reaching nearly 50%, but decreased gradually toward the neonatal period. The findings of this study suggest that, after the migration of neural crest cells, marked cell proliferation in the meninx begins. Differentiation into various layers then follows and is almost complete before birth, whereas the proliferation of arachnoid cells continues even in the early neonatal period.

Animals↗
PubMed1990

Transferrin receptors in injured brain.

Recent studies have demonstrated the presence of transferrin receptors (Tf-R) in the central nervous system. The present study of Wistar rats with experimentally induced brain injuries, using immunohistochemistry at the light microscopy level, demonstrated the presence of Tf-R in regenerated endothelial cells, reactive astrocytes and in other cells, probably macrophages. Although Tf-R were seen in proliferating cells, Tf-R were also observed in non-proliferating cells, many of them macrophages. The receptors perhaps bind transferrin in edema fluid and play an important role in lesion repair.

Animals↗
PubMed1990

Nucleolar organizer regions in meningioma.

Seventy-eight cases of meningioma and related tumors were examined independently using a simple and reproducible argyrophilic method for the demonstration of nucleolar organizer regions (AgNORs) and staining with bromodeoxyuridine monoclonal antibody. The mean number of AgNORs per cell and the bromodeoxyuridine labeling index were shown to be linearly related (r = 0.84, P less than 0.001). The mean AgNOR number was 2.99 for meningeal sarcoma, 2.29 for anaplastic meningioma, 2.08 for hemangiopericytic meningioma. 1.72 for recurrent meningioma without atypical histological findings, and 1.52 for nonrecurrent meningioma. We noted that the mean number of AgNORs reflected the cellular kinetics of a tumor and was related to histological grade and clinical behavior.

Bromodeoxyuridine↗
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↗
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↗
PubMed1987

Catalase gene of the yeast Candida tropicalis. Sequence analysis and comparison with peroxisomal and cytosolic catalases from other sources.

A clone harbouring the genomic DNA sequence for the peroxisomal catalase of an n-alkane-utilizable yeast, Candida tropicalis, has been isolated by the hybrid-selection method and confirmed with a probe of catalase partial cDNA. Nucleotide sequence analysis of the cloned DNA disclosed that the gene fragment coding for catalase had a length of 1455 base pairs (corresponding to 485 amino acids; m = 54937 Da), and that the size of this enzyme was the smallest among all catalases reported hitherto. No intervening sequence was found in this coding region and some portions coincided with the amino acid sequences obtained from the analysis of the purified catalase. The comparison with three peroxisomal catalases from rat liver, bovine liver and human kidney, and one cytosolic catalase from Saccharomyces cerevisiae has revealed that catalase from C. tropicalis was more homologous to the peroxisomal enzymes than to the cytosolic one. C. tropicalis used the codons of the high-expression type. Amino acid residues were all conserved at the active and heme-binding sites. In the N and C-terminal regions there was no characteristic signal sequence or consensus sequence. However, a noticeable region, which can be discriminated between peroxisomal and cytosolic catalases, was proposed.

Amino Acid Sequence↗
PubMed1987

Peroxisomal acyl-coenzyme A oxidase multigene family of the yeast Candida tropicalis; nucleotide sequence of a third gene and its protein product.

We have determined the complete nucleotide sequence of gene POX2, which encodes one of the major peroxisomal polypeptides (PXPs) of Candida tropicalis. POX2 is linked to gene POX4, which codes for a subunit (PXP-4) of long-chain acyl-CoA oxidase. Southern blot analysis revealed that POX2 had a significant homology to POX4, and also to gene POX5 which encodes a subunit (PXP-5) of the isozyme of acyl-CoA oxidase. PXP-2, the protein product of POX2, was co-purified with PXP-4 from the isolated peroxisomes. PXP-2 itself was a flavoprotein and likely to form an equimolar complex with PXP-4, although its enzymatic activity was uncertain. POX2 corresponds to a single open reading frame of 724 amino acids and has no introns. The N-terminal sequence and the calculated Mr of the deduced polypeptide were consistent with those of isolated PXP-2. The primary structure was highly homologous to those of PXP-4 and PXP-5 in respect of the amino acid sequence and the hydropathy profile. We conclude that POX2 is a third gene of the peroxisomal acyl-COA oxidase multigene family.

Acyl-CoA Oxidase↗
PubMed1986

Two acyl-coenzyme A oxidases in peroxisomes of the yeast Candida tropicalis: primary structures deduced from genomic DNA sequence.

We report the complete nucleotide sequence of two genes encoding major peroxisomal polypeptides (PXPs) of Candida tropicalis. One, POX4, encodes PXP-4, which is the most abundant polypeptide in cells grown on oleic acid, and the other, POX5, is the gene for PXP-5. Each of the two polypeptides was found to be the subunit of a distinct long-chain acyl-coenzyme A oxidase: acyl-CoA oxidase II (PXP-4) or acyl-CoA oxidase I (PXP-5). Both the genes had no intron and gave a single open reading frame. The NH2-terminal sequences, except the initiator methionine, and the calculated molecular weights of the deduced polypeptides were consistent with those of the respective PXPs. Well-conserved sequences of 12 and 16 hydrophobic amino acids were present in the middle of the polypeptide, instead of at the NH2 terminus, and may be internal signal sequences for the peroxisomal location of PXPs. Although the two polypeptides were significantly homologous throughout their sequences, the local homologies in two regions out of five were markedly diverged from the average (63%); the homology in the second region was 93%, whereas that in the fourth one was only 24%. The implications of this finding are discussed in respect to the multiplicity of peroxisomal enzymes and the presence of multifunctional proteins in peroxisomes.

Acyl Coenzyme A↗
PubMed1984

High-level expression and molecular cloning of genes encoding Candida tropicalis peroxisomal proteins.

The development of peroxisomes in the cells of Candida tropicalis grown on oleic acid was accompanied by a markedly high expression of peroxisomal proteins. On the basis of this finding, the nuclear DNA library of this yeast was screened by differential hybridization, and 102 clones of oleic acid-inducible sequences were isolated. Seven coding regions were found to form clusters in three stretches of the genomic DNA. Five of the regions were identified as genes for peroxisomal polypeptides (PXPs). The coding sequence for PXP-2 hybrid selected an additional mRNA for PXP-4, the subunit of long-chain acyl coenzyme A oxidase, which was the most abundant PXP. PXP-2 and PXP-4 were close in apparent molecular weight and generated similar peptides when digested with a protease. The gene for PXP-4 was adjacent to that for PXP-2 on the genome and also hybridized to the mRNA coding for PXP-5. These and other similar results suggest that the genes for the peroxisomal proteins of this organism arose by duplication of a few ancestral genes.

Animals↗
PubMed1982

Absence of DNA in peroxisomes of Candida tropicalis.

Yeast peroxisomes were purified to near homogeneity from cells of Candida tropicalis grown on oleic acid for the purpose of examining the possible presence of DNA in this organelle. The purification procedure includes the effective conversion of cells to spheroplasts with Zymolyase and sodium sulfite and the separation of the organelles at extremely low ionic strength. The mitochondrial contamination was less than 1%, based on several criteria, and the yield of peroxisomes was about 40%. The purified peroxisomal fraction contained a very small amount of DNA, which yielded restriction fragments indistinguishable from those of mitochondrial DNA. The absence of DNA in peroxisomes was also supported by cesium chloride density gradient centrifugation of the organelles lysed with a detergent, staining of the organelles with a fluorescent dye specific to DNA, and labeling of the DNA with [3H]adenine.

Adenine↗