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Biomedical subjects

T Orita

Publications and source records attributed to T Orita.

At least 55 records · Page 3Linked to original sources
PubMed1992

[Ruptured aneurysm at the peripheral branch of the posterior cerebral artery with systemic lupus erythematosus].

We report a 73-year-old woman with systemic lupus erythematosus (SLE) in whom intracerebral and intraventricular hemorrhage developed secondary to a ruptured aneurysm on the peripheral branch of the posterior cerebral artery. We reviewed data on 22 patients (43 aneurysms) in previous reports of ruptured cerebral aneurysms associated with SLE, including our case. Of these aneurysms, 34 (79.1%) were located on the major artery, and 9 (20.9%) were located on the peripheral small artery. Fusiform aneurysms accounted for 27.9% of the total. The prognosis was poor, and 14 patients (63.6%) died. Direct aneurysmal surgery was performed in 11 patients (50%), but 4 patients died of other diseases associated with SLE.

Aged↗
PubMed1991

Suicide process of renal cell carcinoma cells encountering mumps virus.

Renal cell carcinoma cells produced the substance(s) which killed them (suicide factor(s)) after co-culture with mumps virus. The suicide factor(s) were heat-sensitive and were degraded with trypsin. Furthermore, actinomycin D inhibited the production of the substance(s) by cancer cells. Considering these facts, the substance(s) were thought to be protein(s) derived from de novo synthesis in cancer cells. It was demonstrated that renal cell carcinoma cells proliferated with the autocrine loop of interleukin-6 (IL-6). Mumps virus almost completely inhibited the IL-6 production in several hours. Because of these two facts, the suicide process might be initiated in renal cell carcinoma cells after encountering mumps virus, i.e. inhibition of the autocrine growth loop of IL-6 followed by the induction of an autocrine killing loop of unknown substance(s).

Carcinoma, Renal Cell↗
PubMed1991

Primitive neuroectodermal tumor of the leptomeninges.

Primitive neuroectodermal tumor (PNET) without an obvious intraparenchymal mass lesion and with diffuse spread in the subarachnoid space is rare. We report such a rare case and discuss the computed tomography (CT) and magnetic resonance (MR) features.

Adolescent↗
PubMed1991

Major histocompatibility complex expression in brain of rats with graft-versus-host disease.

In a healthy state, the central nervous system (CNS) is believed to be an immunologically privileged site, which does not participate in the immune reactions of the rest of the body, and in which identifiable components of the immune system are rare or non-existent. In this study, an immunohistochemical examination of the CNS of F1 hybrid rats following induction of graft-versus-host disease (GVHD) was carried out to determine whether specific immune reactions in the normal CNS could occur during a systemic immune reaction. The results revealed extensive parenchymal and vascular expression of class I and II major histocompatibility complex (MHC) encoded cell surface molecules. The strongest expressors of class I and II molecules were endothelial cells and parenchymal cells, respectively, the latter being apparently activated microglia, in the cerebrum and cerebellum of rats with GVHD. In addition, occasional scattered lymphocytes were detected in the CNS of GVHD rats without blood-brain barrier disruption. Thus, evidence was obtained for the presence of immune responses such as MHC antigen expression and lymphocyte infiltration in the CNS during a strong systemic immune response such as GVHD, microglia and endothelial cells apparently playing an important role.

Animals↗
PubMed1991

cDNA clones of Japanese hepatitis C virus genomes derived from a single patient show sequence heterogeneity.

Twelve cDNA clones of Japanese hepatitis C virus (HCV) have been isolated from liver tissue of a single non-A, non-B hepatitis patient. These clones represented the non-structural domains of HCV. The degree of substitution in the nucleotide sequences and deduced amino acid sequences between these clones was 9.5 and 7.7%, respectively. This high level of substitution suggested that repeated infections of different HCVs may have occurred in the patient.

Amino Acid Sequence↗
PubMed1991

Brain metastasis of testicular tumor with massive hemorrhage--report of two cases.

The authors report two cases of brain metastasis from testicular tumor with massive, sudden intratumoral hemorrhage. In both cases, the hemorrhage occurred during the 1st admission day and carried a high risk of fatality. Early, aggressive surgical removal is advisable before general deterioration. Postoperative chemotherapy with an agent different from the one applied to primary lesion is also recommended because of drug tolerance.

Adult↗
PubMed1991

[Immunohistochemical expression of alpha-1-antitrypsin in human gliomas].

The present paper describes the analysis of immunostaining patterns of four antibodies, alpha-1-antitrypsin (alpha-AT), glial fibrillary acid protein (GFAP), S-100 protein (S-100), and vimentin in 31 human gliomas. The gliomas were 10 astrocytomas, 10 anaplastic astrocytomas, and 11 glioblastoma multiforme tumors. The immunoreactivity for vimentin and alpha-AT that is one of the main proteinase inhibitors changed in proportion to the degree of histological malignancy. As alpha-AT was localized mainly in the cytoplasm of tumor cells and partially in extracellular spaces, it was thought to have been derived from tumor cells. Preparations immunolabelled with anti-GFAP and anti-S-100 showed no increasing loss of immunoreactivity parallel with increasing malignancy.

Adolescent↗
PubMed1991

[Quantification of wallerian degeneration of the pyramidal tract in the capsular region by magnetic resonance imaging].

Using magnetic resonance imaging, we studied 23 patients with motor deficit associated with cerebrovascular disease of the internal capsule. According to the severity of the motor deficits, 23 patients were divided into three groups (severe group...9, moderately severe group...8, mild group...6). A coronal T2-weighted image was obtained along a straight line between the front edge of the medulla and the deepest point of the interpeduncular cistern in a midsagittal T1-weighted image. It was revealed that wallerian degeneration extended continuously from part of the internal capsule down to the pons or medulla or the decussation in all patients. The area of wallerian degeneration in the pons and the area of half the pons were calculated from the coronal T2-weighted image. Moreover, the wallerian index was calculated as: (area of wallerian degeneration in pons divided by area of half the pons) X 100. Values of the wallerian index +/- SD were 26.4 +/- 5.1 in the severe group, 19.2 +/- 5.6 in the moderately severe group, and 10.0 +/- 5.4 in the mild group. There were significant differences among the three groups. We concluded that the area of wallerian degeneration was related to the severity of motor deficits.

Adult↗
PubMed1991

[Comparison of positivity between density gradient centrifugal method and whole blood method in lymphocyte surface marker analysis with flow-cytometry].

The lymphocyte surface marker analysis with flow-cytometry is usually performed using a density gradient centrifugal method or a whole blood method. We have compared these two methods using several monoclonal antibodies and have found the significant difference in positivity all monoclonal antibodies except TCR-1 (anti alpha/beta receptor on T-lymphocyte). We found the significantly higher positivity of Leu12 and HLA-DR as well as lower of the other monoclonal antibodies by using whole blood method than by density gradient centrifugal method. We conclude that it is necessary to make a distinct description of the method used in the surface marker analysis.

Adult↗
PubMed1990

O-linked sugar chain of human granulocyte colony-stimulating factor protects it against polymerization and denaturation allowing it to retain its biological activity.

Human granulocyte colony-stimulating factor (hG-CSF) is a glycoprotein carrying one O-linked sugar chain. To clarify the role of the oligosaccharide in hG-CSF, some biological and physicochemical properties of the deglycosylated hG-CSF and the intact factor were compared. Recombinant hG-CSF produced in transfected Chinese hamster ovary cells was sequentially digested with neuraminidase and endo-alpha-N-acetylgalactosaminidase. The deglycosylated hG-CSF was one-third as active as the intact form in the colony-forming assay, but it was almost as active as the intact hG-CSF in the cell proliferation assay using NFS-60 cells (NFS-60 bioassay). Inactivation of the deglycosylated hG-CSF was also found by NFS-60 bioassay after incubation for 2 days at pH values from 7 to 8 and at 37 degrees C. This inactivation was accompanied by polymerization of the factor which did not occur with the glycosylated factor. Circular dichroic and calorimetric analyses demonstrated that the deglycosylated hG-CSF is more sensitive to heat denaturation than the intact form and that the inactivation of both forms of hG-CSF was accompanied by conformational change of the proteins. From these results, it was concluded that the O-linked sugar chain of hG-CSF contributes to the stability of the factor by suppressing polymerization and/or its conformational changes.

Amino Acids↗
PubMed1990

Thrombopoietic activity of human interleukin-6.

Thrombopoietin (TPO), a regulatory factor in platelet production, was purified from the conditioned medium of TNK-01 cells cultured in the presence of human interleukin-1. The N-terminal sequence of purified TPO was determined to be VPPGEDSKDVAAPHRQPLT, identical to that of the N-terminal region of human interleukin-6 (IL-6). Two forms of TPO with molecular masses of 24 and 27 kDa were identified as IL-6 by Western analysis using an anti-IL-6 antibody. Commercial recombinant human IL-6 produced in Escherichia coli, stimulated megakaryocyte colony formation in the presence of mouse interleukin-3 and increased the number of peripheral platelets in mice in a dose-dependent manner. From these results, it is concluded that human IL-6 has thrombopoietic activity.

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

Physicochemical and biological comparison of recombinant human erythropoietin with human urinary erythropoietin.

Physicochemical and biological properties of recombinant human erythropoietin (rhEPO) were compared with human urinary erythropoietin (uEPO). uEPO and rhEPO were purified to apparent homogeneity from the urine of patients with aplastic anemia and from the conditioned medium of Chinese hamster ovary (CHO) cells transfected with a cDNA clone for human EPO, respectively. The microheterogeneous nature of both factors, observed on isoelectric focusing, is derived from the difference of the number of terminal sialic acid residues bound to the carbohydrate chains of the EPO molecule. The primary structure of rhEPO, consisting of 165 amino acid residues, was determined, and the C-terminal arginine predicted from the cDNA sequence was confirmed to be missing, as described previously (Recny et al. (1987) J. Biol. Chem. 262, 17156). Three N-glycosylation and one O-glycosylation sites of both factors were determined as Asn24, Asn38, and Asn83 and Ser126, respectively. Two disulfide linkages are located between Cys7 and Cys161, and between Cys29 and Cys33, in both EPOs. Hematogenic potencies of rhEPO and uEPO compared in normal and in partially nephrectomized rats were approximately the same. Both factors also stimulated the colony formation of CFU-E, BFU-E, and CFU-Meg in a dose-dependent manner. From these results, it is concluded that rhEPO produced in CHO cells transfected with cDNA clone for human EPO is indistinguishable from uEPO physicochemically and biologically, and is valuable for further research and for clinical use.

Amino Acid Sequence↗
PubMed1990

Structural characterization of natural and recombinant human granulocyte colony-stimulating factors.

Granulocyte colony-stimulating factor (G-CSF) is a glycoprotein which stimulates predominantly neutrophilic granulocyte colony formation in mammals. Natural human G-CSF (hG-CSF) and recombinant hG-CSF produced in Chinese hamster ovary (CHO) cells transfected with the cDNA clone for hG-CSF have been purified to apparent homogeneity for structural and biological comparison. The amino acid sequence of recombinant hG-CSF, composed of 174 amino acid residues, was identical with that of natural hG-CSF and also with the sequence predicted from the cDNA. Both forms of hG-CSF have a free Cys-17 and two intramolecular disulfide linkages, between Cys-36 and Cys-42, and between Cys-64 and Cys-74. The O-glycosylation occurred at Thr-133 in both hG-CSFs. Similar CD spectra were obtained for both hG-CSFs. Additionally, both forms showed almost the same biological activities determined by in vitro colony-forming assay and in vivo assay. It is thus concluded that the recombinant hG-CSF is indistinguishable from its natural counterpart and that the former is valuable for more detailed characterization and clinical use.

Amino Acid Sequence↗
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↗