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Biomedical subjects

N Ohara

Publications and source records attributed to N Ohara.

At least 145 records · Page 8Linked to original sources
PubMed1994

Characterization of two polysaccharides having activity on the reticuloendothelial system from the root of Rehmannia glutinosa.

Two acidic polysaccharides, called rehmannan SA and rehmannan SB, were isolated from the dried root of Rehmannia glutinosa Liboschitz. They were homogeneous on electrophoresis and gel chromatography, and their molecular masses were estimated to be 6.4 x 10(4) and 7.9 x 10(4), respectively. They were commonly composed of L-arabinose:D-galactose:L-rhamnose:D-galacturonic acid in the molar ratios of 10:10:1:1 (rehmannan SA) and 14:7:3:8 (rehmannan SB), in addition to small amounts of peptide moieties. About eighty percent (rehmannan SA) and about thirty percent (rehmannan SB) of the hexuronic acid residues exist as methyl esters. Reduction of carboxyl groups, methylation analysis, nuclear magnetic resonance and the controlled Smith degradation studies indicated the structural features of rehmannan SB, the major one in terms of the yield. It has a core structural unit of a characteristic rhamnose-rich arabino-3,6-galactan type. Both polysaccharides showed remarkable reticulo-endothelial system-potentiating activity in a carbon clearance test.

Animals↗
PubMed1994

Characterization of a novel glucan, which exhibits reticuloendothelial system-potentiating and anti-complementary activities, from the rhizome of Cnidium officinale.

A novel glucan, called cnidirhan SI, was isolated from the rhizome of Cnidium officinale Makino. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 1.3 x 10(4). It is composed of D-glucose alone, in addition to small numbers of O-acetyl groups. Methylation analysis, nuclear magnetic resonance and enzymic degradation studies indicated it has a high-branched glucan type structure composed of alpha-1,4-linked D-glucopyranose residues with both 3,4- and 4,6-branching points. The glucan showed significant reticuloendothelial system-potentiating activity in a carbon clearance test, as well as pronounced anti-complementary activity. This substance is the first example of a branched alpha-glucan with phagocytosis-stimulating and anti-complementary activities.

Adult↗
PubMed1994

Analysis of adrenocortical hyperplasia by computed tomography in patients with Cushing's Disease, idiopathic hyperaldosteronism and adrenogenital syndrome.

We assessed the usefulness and reliability of computed tomography (CT scan) in evaluating adrenal hyperplasia in 38 patients, including 14 with Cushing's disease, 17 with idiopathic hyperaldosteronism (IHA), and 7 with the adrenogenital syndrome (AGS). Eighty-two normal subjects were also examined. We analyzed the shape of the adrenal gland and quantitated its thickness, width and length. Visual inspection revealed V-shaped right adrenal glands in 100% of patients with Cushing's disease, 94% of patients with IHA, 100% of patients with AGS and in 41% of the normal subjects. Triangular left adrenal glands were observed in 100% of patients with Cushing's disease, 82% of patients with IHA, 67% of patients with AGS and in 12% of the normal subjects. Quantitative analysis showed that the right adrenal gland was significantly thicker and longer in patients with Cushing's disease, IHA and in those with AGS than in normal subjects. The right adrenal gland was significantly wider in the patients with Cushing's disease and AGS than in control subjects. The left adrenal gland was significantly wider and longer in patients with Cushing's disease and AGS than in the normal controls. Analysis of individual data indicated that the upper limit of normal for thickness of the right adrenal was 7 mm. Therefore, adrenal hyperplasia was strongly suggested when the right adrenal gland was more than 7 mm thick. Our findings suggest that the CT scan is useful and reliable in diagnosing adrenal hyperplasia.

Adrenal Cortex↗
PubMed1994

Acquired amegakaryocytic thrombocytopenic purpura with humoral inhibitory factor for megakaryocyte colony formation.

A 67-year-old man with thrombocytopenia, and amegakaryocytic but otherwise normal bone marrow, was evaluated. Antibody against thrombocytes was negative and the half-life of thrombocytes was normal. In vitro clonal culture of the patient's bone marrow cells yielded no megakaryocyte colony with normal granulocyte-macrophage and erythroid colony formation. Megakaryocyte colony formation of the control bone marrow cells was significantly suppressed by the addition of the patient's serum to the culture, suggesting the existence of humoral inhibitory factor(s) for megakaryocyte colony formation. Therapeutic trials with plasma exchange, cyclosporine, prednisolone, and cyclosporine plus prednisolone were all unsuccessful, but serious bleeding has been absent.

Aged↗
PubMed1993

Cloning, sequencing and expression of the gene for alpha antigen from Mycobacterium intracellulare and use of PCR for the rapid identification of Mycobacterium intracellulare.

The complete nucleotide sequence of alpha antigen secreted from Mycobacterium intracellulare (ATCC13950) was determined. The gene encoded 330 amino acids including 40 amino acids for signal peptide, followed by 290 amino acids for a mature protein with molecular mass 30,645 Da. The cloned gene was expressed in Escherichia coli by using an E. coli expression vector. Based on these results, the feasibility of rapid identification of M. intracellulare by two step polymerase chain reaction (PCR) was demonstrated.

Amino Acid Sequence↗
PubMed1993

Isolation and amino acid sequence of the 30S ribosomal protein S19 from Mycobacterium bovis BCG.

The 30S ribosomal proteins from Mycobacterium bovis BCG were separated by reverse phase-high performance liquid chromatography (RP-HPLC). The isolated proteins were analyzed by SDS-PAGE, blotted on PVDF-membranes and subjected to sequence analyses using a gas-phase sequencer to correlate them to those of the well studied Escherichia coli and Bacillus stearothermophilus ribosomes. Moreover, the internal amino acid sequence of one ribosomal protein, MboS19, which is homologous to E. coli ribosomal protein S19 (EcoS19) and B. stearothermophilus ribosomal protein S19 (BstS19), was further analyzed by sequencing its internal peptides and two segments from the N- and C-termini of the protein were selected to deduce the sequence of two oligonucleotide primers which were used in a polymerase chain reaction. Using the amplified DNA fragment thus obtained as a hybridization probe, the gene encoding protein S19 was identified and cloned. Sequence analysis of the DNA fragment, together with peptide sequence analysis could determine the complete amino acid sequence of MboS19. This sequence proved to be 64% and 71% identical to those of the corresponding S19 proteins from the eubacteria E. coli, and B. stearothermophilus, respectively; 33% of the residues of MboS19 were identical to those in the archaebacterial ribosomal protein HmaS19.

Amino Acid Sequence↗
PubMed1993

Gliosarcoma with features of chondroblastic osteosarcoma.

BACKGROUND: The occurrence of osteoid-chondral elements in gliosarcoma is extremely rare and has been reported in only two cases. A new, rare case of gliosarcoma with osteosarcomatous differentiation in a 55-year-old man and histogenesis of osteoid-chondral tissue in gliosarcoma is discussed. METHODS: Surgically removed tumor tissues were examined immunohistochemically and electron microscopically, and a histologic examination was performed. RESULTS: Immunohistochemical and electron microscopic studies confirmed the presence of glial, fibroblastic, and osteoid-chondral elements. A major part of the sarcomatous tissue was undifferentiated and stained only by vimentin. Some areas of osteoid-chondral tissue were positive for glial fibrillary acidic protein (GFAP). CONCLUSIONS: These data suggest that osteoid-chondral elements came from the sarcomatous portion and GFAP positivity is not restricted to astrocytes and has been seen particularly in chondroid areas of non-glial tumors.

Brain Neoplasms↗
PubMed1993

A novel monoclonal antibody specifically reactive with human T-lymphotropic virus type-II (HTLV-II) envelope protein.

A novel monoclonal antibody (MAb), N5.4.4, specifically reactive with human T-lymphotropic virus type-II (HTLV-II) envelope glycoprotein (gp) has been developed through immunization with a synthetic peptide corresponding to the amino acid sequence 171-196 of the HTLV-II envelope protein (II-env 171-196). This MAb, which belonged to the IgG1 kappa subclass, reacted with the cytosmears of HTLV-II-infected cell lines (Si-IIA, CR-IIA-I and AS-IIA), but not with those of HTLV-I-infected cell lines (MT-1 and MT-2) or other HTLV-uninfected cell lines. On Western blot analysis, this MAb reacted with gp46 of HTLV-II lysates but not with HTLV-1 lysates. Moreover, flow-cytometric analysis revealed that this MAb recognized the native surface of only the HTLV-II-producing cells. Through application to immunohistochemical or serological method, this MAb may be of value in elucidating the pathogenesis of HTLV-II infection in comparison with HTLV-I.

Amino Acid Sequence↗
PubMed1993

Co-expression of CD4 and CD8 associated with elevated interleukin-4 in a cord T cell line derived by co-cultivating normal cord leukocytes and an HTLV-II-producing simian leukocyte cell line (Si-IIA).

A new interleukin-2(IL-2)-dependent T cell line, designated CS-IIA, was established by co-cultivating normal human cord leukocytes and a lethally X-irradiated HTLV-II-producing simian leukocyte cell line (Si-IIA). CS-IIA showed CD4 dominance during the early culture. However, after addition of IL-2, CS-IIA predominantly co-expressed CD4 and CD8 (69.5%) and also expressed the surface markers CD1-, CD3+, CD19-, CD25+ and HLA-DR+. A significantly elevated level of IL-4 (1697 pg/ml) was observed in the culture supernatant from CS-IIA. In addition, the conversion of phenotype from some CD4+CD8+ cells to CD4+CD8- was demonstrated by the neutralization assay using anti-IL-4 antibody. CS-IIA had a normal human karyotype and was free from Epstein-Barr virus nuclear antigen and immunoreactive with sera of HTLV-I- or HTLV-II-infected patients and anti-HTLV-1, p19 or p24 mAb. The provirus genome of HTLV-II was detected in this cell line by the polymerase chain reaction combined with a digoxigenin-enzyme-linked immunosorbent assay. However, electron microscopy of CS-IIA cells revealed no C-type virus particles in the extracellular space. These results indicate that HTLV-II can be transmitted from an HTLV-II-infected simian leukocyte cell line to human cord T lymphocytes and suggest that co-expression of CD4 and CD8 on T cells may be induced by the high level of IL-4, which can mediate CD8 induction on CD4+ T cell clones.

CD4-CD8 Ratio↗
PubMed1993

Development of autoimmune thyroid dysfunction after bilateral adrenalectomy in a patient with Carney's complex and after removal of ACTH-producing pituitary adenoma in a patient with Cushing's disease.

Although the factors that cause developments or exacerbations of autoimmune thyroid dysfunction are not known, the changes of glucocorticoids might modulate the autoimmune responses. We compared the postoperative changes in thyroid function in one patient with Carney's complex with primary adrenocortical nodular dysplasia (PAND) and 19 patients with Cushing's disease due to ACTH-producing pituitary adenoma. Thyroid dysfunction developed after surgery for glucocorticoid excess in two patients; one with Carney's complex had transient hypothyroidism after bilateral adrenalectomy for PAND, and the other had transient hyperthyroidism due to thyroiditis after removal of ACTH-producing pituitary adenoma for Cushing's disease. Both patients had no thyroid autoantibodies at the time of surgery. None of the remaining 18 patients had clinically evident thyroid disease or increased antithyroidantibody titers. Development of autoimmune thyroid dysfunction may be observed after surgery for glucocorticoid excess in the patients with any forms of Cushing's syndrome, even who do not have thyroid antibodies.

Adenoma↗
PubMed1993

Structure-function relationship in secondary biliary cirrhosis in the rat. Stereologic and hemodynamic characterization of a model.

Secondary biliary cirrhosis in the rat is an attractive model since unlike other models it does not rely on exogenous toxic compounds to induce cirrhosis. However, because little is known about the microcirculatory abnormalities of this model, this study investigated hemodynamics in rats with predefined functional impairment and related them to different aspects of stereologically quantified structure. All animals with at least 50% reduction in microsomal function, assessed by the aminopyrine breath test, had portal hypertension. The sinusoidal space, as assessed by multiple indicator dilution in the perfused liver, was reduced whereas large vessel space was increased. This reduction in sinusoidal space could contribute to increased portal resistance. The degree of intrahepatic shunting varied as assessed by a microsphere technique (13.9 vs. 0.5% in controls). These alterations were confirmed by stereological analysis. Numerically, there was excellent agreement between functional indicator dilution data and anatomic quantitation. Microvascular exchange was impaired as in other models of cirrhosis as shown by a reduced extravascular albumin space (4.5 vs. 2.2%, p < 0.01). In contrast to alterations in vascular space, this functional impairment was not reflected in the stereologically assessed space of Disse which averaged 5% of liver volume in both groups. Finally, in spite of reduced microsomal function in vivo (aminopyrine breath test) and in vitro (aminopyrine N-demethylase activity), the smooth endoplasmic reticulum was maintained (4.3 vs. 3.5 m2/ml cytosol, n.s.), which demonstrates that microsomal function in this model is reduced per unit hepatocyte. This suggests that the sick-cell hypothesis applies to secondary biliary cirrhosis in the rat.

Aminopyrine↗
PubMed1993

A human T cell line with an abnormal trisomy 2 karyotype established by coculture of peripheral lymphocytes with an HTLV-II-infected simian leukocyte cell line.

A new human T cell line with a chromosomal abnormality (47,XY,+2), designated AS-IIA, was established by coculturing peripheral blood leukocytes of a healthy adult male with a lethally irradiated human T lymphotropic virus type II (HTLV-II)-infected simian leukocyte cell line (Si-IIA). A polymerase chain reaction method showed that this interleukin-2 (IL-2)-dependent cell line possessed the HTLV-II provirus genome; the cells also reacted with HTLV-II-positive human sera, anti-HTLV-I/II p24, and anti-HTLV-II gp46 antibodies. AS-IIA cells expressed the suppressor/cytotoxic T cell markers CD3+, CD4-, CD8+, CD25+, and HLA-DR+, with later conversion to CD8-. These cells showed better proliferation than other human HTLV-II-infected cell lines with normal karyotypes, but were not transplantable into severe combined immunodeficiency mice. Virus production from AS-IIA was confirmed not only by electron microscopic examination, which revealed mature and immature type C virus particles, but also by the capacity of the line to immortalize human T cells. These results suggest that HTLV-II shows broad tropism for T cells including CD4+ or CD8+, and that not only Si-IIA, but also AS-IIA, are good sources of HTLV-II. The authors of the present study believe that AS-IIA may be a useful human T cell line for the investigation of HTLV-II in comparison with HTLV-I.

Adult↗
PubMed1993

Cloning and sequencing of the gene for alpha antigen from Mycobacterium avium and mapping of B-cell epitopes.

The complete nucleotide sequence of alpha antigen secreted from Mycobacterium avium (A-alpha) was determined. The gene encodes 330 amino acids, including 40 amino acids for the signal peptide, followed by 290 amino acids for the mature protein with a molecular mass of 30,811 Da. This is the first sequence of A-alpha. Comparisons between A-alpha and alpha antigens of Mycobacterium leprae, Mycobacterium bovis BCG, and Mycobacterium kansasii showed highly homologous regions which suggested a conserved functional domain and two less-homologous regions. Serological analysis of recombinant A-alpha, expressed by a series of deletion constructs, indicated the possibility that A-alpha carries at least six B-cell epitopes. The three antigenic determinants were common to Mycobacterium tuberculosis, M. kansasii, and M. avium. The results also suggested the possibility that there are three species-specific epitopes.

Amino Acid Sequence↗
PubMed1993

Immunological properties of ribosomal proteins from Mycobacterium bovis BCG.

Two proteins with molecular mass 65 kDa, a heat shock protein, and an S1-like protein were found in a 30S ribosomal subunit from Mycobacterium bovis BCG. The 17-kDa protein in the 30S subunit was homologous to alpha-crystallin heat shock protein, and the 16-kDa protein in the 50S subunit was homologous to the L7/L12 protein. The latter provoked a strong delayed-type hypersensitivity reaction in the sensitized guinea pigs. The GroES-like protein (12 kDa) loosely associated with ribosomes.

Animals↗
PubMed1993

Increased pulmonary vascular permeability in rats with biliary cirrhosis: role of thromboxane A2.

Rats with liver cirrhosis exhibit arterial hypoxemia and loss of hypoxic pulmonary vasoconstriction similar to some patients with end-stage liver disease. We hypothesized that the pulmonary circulatory dysfunction in cirrhosis results from vascular endothelial cell injury and interstitial lung edema. To investigate this hypothesis, we compared the extravascular lung albumin leak, lung ultrastructural changes, and tissue eicosanoid levels in control and cirrhotic rats. In comparison to sham-operated controls, rats with biliary cirrhosis, 6 wk after ligation of the common bile duct, had increased lung albumin leak index (1.46 +/- 0.12 vs. 0.80 +/- 0.04, P < 0.001) and bloodless lung wet-to-dry weight ratio (4.94 +/- 0.05 vs. 4.78 +/- 0.03, P < 0.05). Electron-microscopic sections of lungs from cirrhotic rats demonstrated infiltration with intravascular macrophage-like cells, endothelial cell injury, and interstitial edema. In addition, lung tissue thromboxane B2 was significantly increased in cirrhotic rats, and pretreatment with a thromboxane synthase inhibitor, dazoxiben, reduced lung thromboxane B2 level and attenuated extravascular lung albumin leak (control 1.03 +/- 0.07, cirrhotic 2.29 +/- 0.06, cirrhotic plus dazoxiben, 1.57 +/- 0.17). In contrast, WEB 2086, a platelet-activating factor antagonist, had no effect on lung albumin leak. We conclude that pulmonary vascular permeability is increased in rats with biliary cirrhosis and that thromboxane A2 contributes to the pulmonary circulatory abnormalities in cirrhosis.

Albumins↗