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Biomedical subjects

M Ogata

Publications and source records attributed to M Ogata.

At least 343 records · Page 19Linked to original sources
PubMed1988

IL-2-PE40 is cytotoxic for activated T lymphocytes expressing IL-2 receptors.

IL-2-PE40 is a chimeric molecule in which IL-2 is attached to the amino end of modified Pseudomonas exotoxin molecule lacking cell recognition domain. This molecule was extremely toxic for Con A-stimulated spleen cells from mice. Moreover, IL-2-PE40 has suppressive effect against Ag-activated cells; it inhibits the generation of cytotoxic T lymphocyte activity in a MLC. IL-2-PE40 could be a useful agent in IL-2R targeting therapy including immunosuppressive therapy for allograft rejection or some autoimmune diseases.

Animals↗
PubMed1988

Stimulative effect of chlordane on the various functions of the guinea pig leukocytes.

The effects of the chlordane-related compounds, cis-chlordane, trans-chlordane, heptachlor, and heptachlor epoxide, on stimulation responses of guinea pig polymorphonuclear leukocytes (PMNs) were examined. Treatment of PMN with these compounds stimulated superoxide (O2-) generation, altered membrane potential, and increased intracellular Ca2+ concentration ([Ca2+]i). However, there was no definite tendency among the stimulating effects of chlordane-related compounds, therefore the relationship between the effect and molecular structure of these substances remains unknown. Of these response reactions of PMN stimulated by chlordane-related compounds, stimulation of O2- generation lagged behind others. Increase in [Ca2+]i was due both to acceleration of extracellular Ca2+ penetration and to Ca2+ release from the intracellular pool. These results indicate that chlordane-related compounds stimulate PMN and suggest a causal relationship between the stimulation of O2- generation by these substances and their toxicity.

Animals↗
PubMed1988

Isoelectric focusing of catalase from acatalasemic mouse and human blood, and cultured human skin fibroblasts.

Hemolysates of normal, heterozygous hypocatalasemic and acatalasemic mice and of Japanese acatalasemic subjects were separated into three fractions, A, B and C, by DEAE-cellulose column chromatography, and pI values of A, B and C fractions were determined by isoelectric focusing. The pI value of catalase in the A, B and C fractions increased in the order of normal, hypocatalasemic and acatalasemic mouse blood. The results obtained from Japanese acatalasemic blood samples showed that the pI values of catalase in the A, B and C fractions were similar to those in normal blood. Catalase in Japanese acatalasemic cultured skin fibroblasts was also analyzed by isoelectric focusing. The pI values of catalase in the extract from the cultured skin acatalasemic fibroblasts was similar to that in normal fibroblasts.

Acatalasia↗
PubMed1988

An initiation site of DNA replication with transcriptional enhancer activity present upstream of the c-myc gene.

We have previously reported that c-myc protein may promote cellular DNA replication by binding to initiation sites of replication. Here we report that a putative origin of human cellular DNA replication (ori) is present at approximately 2 kb upstream of the coding region of the c-myc gene itself. The c-myc protein, or protein(s) complexed with c-myc protein, bind to the upstream region (approximately 200 bp in length) which has transcriptional enhancer activity as well as autonomously replicating activity in human cells, suggesting that the c-myc protein may be an enhancer binding protein as well as a DNA replication protein. Results with deletion mutants suggest that the sequence essential to the origin of DNA replication may be adjacent to, but cannot be clearly separated from, the sequence responsible for enhancer activity. Furthermore, when cloned DNA containing putative c-myc protein binding sequences was transfected as competitor into HL-60 cells, expression of c-myc was inhibited, suggesting that c-myc protein itself may be necessary for c-myc expression.

Base Sequence↗
PubMed1988

Low-density lipoprotein oxidized by polymorphonuclear leukocytes inhibits natural killer cell activity.

We studied the effect of low-density lipoprotein (LDL) oxidized by opsonized zymosan-stimulated polymorphonuclear leukocytes (PMN) on natural killer (NK) cell activity. Oxidized LDL inhibited NK cell activity in a dose-dependent manner, whereas normal LDL left it unaffected. However, oxidized LDL did not inhibit antibody-dependent cell-mediated cytotoxicity (ADCC). Moreover, a positive correlation was observed between the amount of thiobarbituric acid-reacting substances (TBARS) on the sample of oxidized LDL and the degree of inhibition of NK cell activity. We also showed that oxidized LDL suppressed the binding capacity of purified large granular lymphocytes (LGL) to target cells without changing the lytic activity. These results therefore suggest that activated PMN can modulate NK cell activity by oxidizing LDL.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1988

Thymic stroma-derived T-cell growth factor (TSTGF): II. Biochemical and functional characterization.

The culture supernatant (SN) from a cloned line of thymic stroma-derived cells in fibroblastic form (TSCF) contained a factor capable of supporting the growth of the interleukin (IL) 2-dependent, antigen-specific helper T cell (Th) clone 9-16 without requiring IL2 and antigen. This active substance, designated as thymic stroma-derived T-cell growth factor (TSTGF), was partially purified through DEAE-Sephacel chromatography and PBE 94 chromatofocusing. The original SN did not contain IL1, IL2, IL3, IL4, or interferon activities; but an appreciable magnitude of colony-stimulating factor (CSF) activity in addition to TSTGF was present, whereas the partially purified preparation of TSTGF was depleted of any type of CSF activity. The elution profile of TSTGF activity on the chromatofocusing has revealed that TSTGF has an isoelectric point (pI) of about 6.0. When a purified TSTGF sample was applied to Sephacryl S-200 column chromatography and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, TSTGF activity was eluted in a single peak around an apparent molecular weight of about 25,000. The activity of TSTGF also was shown to be relatively stable with heat treatment and in the wide range of pH, but it was abolished by treatment with either trypsin or dithiothreitol. These results indicate that TSTGF, a novel T-cell growth factor, is the protein that has an apparent molecular weight of about 25,000 and a pI of 6.0, and in the intact molecule, it contains the disulfide bond(s) required to maintain and/or express its biologic activity.

Biological Products↗
PubMed1988

Simultaneous determination of urinary creatinine and metabolites of toluene, xylene, styrene, ethylbenzene and phenol by automated high performance liquid chromatography.

An attempt was made to establish a method for the direct determination of urinary concentrations of creatinine, hippuric acid, methylhippuric acid and mandelic acid by automated high performance liquid chromatography (HPLC). Urine was diluted with distilled water or mobile phase, then the mixture was centrifuged and the supernatant was injected into HPLC. A stainless-steel column packed with octadecyl silanized silicate was used, and the mobile phase was a solution of [20 mM potassium phosphate monobasic containing 3 mM sodium 1-decanesulfonate]/acetonitrile (85/15). Another HPLC method for the determination of urinary concentration of phenol, metabolites of benzene and/or phenol is also described. Phenyl sulfate and phenyl glucuronide in urine were hydrolyzed enzymatically into phenol. The hydrolyzed mixture was injected into HPLC with the ODS column. The mobile phase was a solution of [20 mM potassium phosphate monobasic containing 1 mM sodium 1-decanesulfonate]/acetonitrile (85/15). The ratio of hippuric acid (HA) concentration to creatinine concentration determined by the urine of students after physical exercise was similar to that before exercise. Moreover, the coefficient of correlation found between the toluene concentration in a workshop and the HA concentration in workers' urine, corrected for creatinine, was higher than that obtained between the toluene concentration and the uncorrected HA concentration. For assays on stored urine samples, urine was spotted on filter paper, dried and kept several weeks, and then MA, HA, o-MHA, m-MHA and creatinine in the filter paper were eluted with 50% methanol and their concentrations determined by HPLC.

Adolescent↗
PubMed1988

Characterization and complete amino acid sequence of ferredoxin II from Desulfovibrio vulgaris Miyazaki.

One of 2 ferredoxins, Fd II, purified from Desulfovibrio vulgaris Miyazaki (DvM) has been characterized and its complete amino acid sequence established. Fd II is composed of 63 amino acid residues and contains 7 cysteinyl residues but has only 4 iron atoms in an iron-sulfur cluster of a standard redox potential of -405 mV. The arrangement of cysteinyl residues in the protein suggests that some cysteinyl residues are not directly involved in ligation to the iron-sulfur cluster. Homology is recognized among Fd II (DvM), Fd I (D. desulfuricans Norway), Fd I (D. africanus Benghazi), and Fd (D. gigas). Although Fd I and Fd II in DvM are poorly homologous, the C-terminal half of Fd I is fairly homologous to the N-terminal half of Fd II. Fd II is 40% as effective as Fd I as an electron carrier for pyruvate dehydrogenase coupled with hydrogenase and cytochrome c3.

Amino Acid Sequence↗
PubMed1988

Comparative immunological and electrophoretic analysis of Gc protein in sera from various animals.

1. On immunodiffusion, using an anti-human Gc antibody, serum Gc in all mammals tested revealed a partial identity with human Gc. 2. The relative cross-reactivities of serum Gc in monkeys, dogs, cats and rats with human Gc antiserum were found to be more than 70% while the serum Gc in other mammals (pigs, cattle, goats and a guinea pig) was less than 50%. 3. Testing, using the isoelectrofocusing method, showed specific patterns of Gc in the mammals. In the sera of cats and cattle, Gc polymorphisms were detected. 4. Neuraminidase treatment affected the isoelectrofocusing Gc patterns of pigs, goats and cattle, whereas those in other mammals remained unchanged.

Alleles↗
PubMed1988

Purification and characterization of ferredoxin from Desulfovibrio vulgaris Miyazaki.

Two ferredoxins, Fd I and Fd II, were isolated and purified from Desulfovibrio vulgaris Miyazaki. The major component, Fd I, is an iron-sulfur protein of Mr 12,000, composed of two identical subunits. The absorption spectra of Fd I and Fd II have a broad absorption shoulder near 400 nm characteristic of iron-sulfur proteins. The purity index, A400/A280, of Fd I is 0.69, and its millimolar absorption coefficient at 400 nm is 3.73 per Fe. It contains two redox centers with discrete redox behaviors. The amino acid composition and the N-terminal sequence of Fd I are similar to those of Fd III of Desulfovibrio africanus Benghazi and Fd II of Desulfovibrio desulfuricans Norway. Fd I does not serve as an electron carrier for the hydrogenase of D. vulgaris Miyazaki, but it serves as a carrier for pyruvate dehydrogenase of this bacterium. The evolution of H2 from pyruvate was observed by a reconstructed system containing purified hydrogenase, cytochrome C3, Fd I, partially purified pyruvate dehydrogenase, and CoA. The H2-sulfite reducing system can be reconstructed from the purified hydrogenase, cytochrome C3, Fd I and desulfoviridin (sulfite reductase), but the reaction rate is very slow compared to that of the crude extract at the same molar ratio of the components.

Amino Acid Sequence↗
PubMed1988

Amino acid sequence of ferredoxin I from Desulfovibrio vulgaris Miyazaki.

The amino acid sequence of ferredoxin (Fd) I, purified from Desulfovibrio vulgaris Miyazaki, has been established. Fd I is strikingly similar to Fd III of D. africanus Benghazi with 84% homology. Both have the sequence, -Cys-x-x-Asp-x-x-Cys-x-x-x-Cys-Pro- in the N-terminal half, and the sequence, -Cys-x-x-Cys-x-x-Cys-x-x-x-Cys-Glu- in the C-terminal half of the molecule, instead of the common sequences for ligation to the usual [4Fe-4S] clusters. Fd I has 76% homology to Fd II of D. desulfuricans Norway.

Amino Acid Sequence↗
PubMed1988

Interaction of cellular hydrogenase, cytochrome c3, and desulfoviridin in Desulfovibrio vulgaris Miyazaki with their antibodies.

Anti-sera for hydrogenase, cytochrome c3, and desulfoviridin (abbreviated as anti-hyd, anti-c3, and anti-dvn, respectively) were raised in mice, and used to locate these antigens in cells of Desulfovibrio vulgaris Miyazaki. The activity of the intact cells to absorb H2 with methyl viologen or sulfite as an electron acceptor was cumulatively inhibited by treating the cells with anti-hyd and anti-c3 but unaffected by anti-dvn treatment. The activity of the intact cells to produce H2 from formate was also inhibited by anti-c3 treatment, but the inhibition by anti-hyd treatment was not significant. The fluorescent antibody technique applied to intact cells of D. vulgaris Miyazaki indicated that both hydrogenase and cytochrome c3 are localized on the surface of the cell. These results are not exactly in conformity with the hydrogen-cycling hypothesis for proton gradient formation in the energy metabolism in Desulfovibrio. The procedure described in the present paper provides a new technique to elucidate the roles of proteins by applying anti-sera to intact cells without destroying the cellular structure.

Antibody Formation↗
PubMed1988

Experimental study on acute aggravating factors of cervical spondylotic myelopathy.

Systemic arterial hypotension, systemic arterial hypertension, cervical hyperflexion, cervical hyperextension, and cervical instability were induced in experimental animal with cervical spondylotic myelopathy, and their effects on spinal cord pathology were investigated. An experimental animal model of cervical spondylotic myelopathy was produced by combining anterior cervical cord compression with occlusion of the cervical vertebral arteries in dogs. Spinal cord pathology at the site of compression was characteristically different and depended on the type of load; that is, peripheral necrosis of the central gray matter in systemic hypotension, capillary congestion and subarachnoid hemorrhage in systemic hypertension, and linear necrosis of the transversely elongated central gray matter combined with occluded anterior spinal artery in cervical hyperflexion, and the pathologic severity was proportional to the number of loadings. This study suggests that cervical spondylotic myelopathy might progress stepwise rather than linearly when these aggravating factors are loaded.

Animals↗
PubMed1988

Mediation of in vivo tumor-neutralizing activity by Lyt-2+ as well as L3T4+ T cell subsets.

The present study reexamines the cell surface nature of T cells mediating in vivo protective tumor immunity with the use of anti-L3T4 and -Lyt-2 antibodies. C3H/HeN mice hyperimmune against syngeneic MH134 hepatoma or MCH-l-Al fibrosarcoma were prepared by intradermal (id) inoculation of viable tumor cells followed by surgical resection of the tumor and by repeated challenges with viable tumor cells. Spleen cells from these mice were fractionated into L3T4+ or Lyt-2+ T cell subset by treatment with anti-Lyt-2 or -L3T4 antibody plus complement (C). Winn assays performed by utilizing such fractionated T cells have revealed that both L3T4+ and Lyt-2+ T cell subsets from hyperimmune mice produced complete tumor protection. Flow microfluorometry study illustrated that the treatment with anti-L3T4 or -Lyt-2 antibody plus C resulted in the complete isolation of L3T4- Lyt-2+ (Lyt-2+) or L3T4+ Lyt-2- (L3T4+) T cell subset, respectively. This contrasted with the failure of treatment with anti-Lyt-1 antibody plus C to isolate all T cells expressing Lyt-2 marker. It was further demonstrated that each subset of T cells exerted its anti-tumor effect in a tumor-specific way and without a requirement for the other alternative subpopulation of unprimed T cells. These results indicate that Lyt-2+ T cell subset can be successfully isolated by treatment with anti-L3T4 but not with anti-Lyt-1 antibody plus C, and that each single subset of Lyt-2+ and L3T4+ T cells can function as in vivo effector T cells.

Animals↗
PubMed1988

Morphological differences in hearts of rats well adapted and poorly adapted to chronic hypoxia.

We carried out an experiment to analyze morphological differences in hearts of rats well adapted and poorly adapted to chronic hypoxia. Male and female Wistar rats, 1 week, 4 weeks and 9 weeks old, were employed on the assumption that adaptive ability was dependent on age and sex. These rats were raised at an altitude of 2,400 m and were kept for 7 to 9 weeks. Control groups were maintained at an altitude of 600 m during the same period of time. Each group consisted of 4 to 6 rats. At the end of the experiment, body weight, heart weight, ratio of heart weight to body weight and hematocrit were measured, and ventricular wall thickness, myocardial fiber diameter, capillary supply and mitochondria were morphometrically studied. Of the 6 experimental groups, the 4-week-old male rats (M2) had the highest body weight, as compared with the other experimental groups. In addition, relative to these other experimental groups, the following features were found for M2. Heart weight was intermediate, heart weight/body weight ratio was low and hematocrit was also low. Ventricular wall thickness was intermediate in the right ventricle (RV) and interventricular septum (IVS) but was thin in the left ventricle (LV). Myocardial fiber diameter was intermediate in the RV, large in the IVS and small in the LV. Capillary supply was intermediate in the RV and dense in the IVS and LV. Mitochondria were small but cristal density and percentage area, estimated from electron micrographs, were found to be high.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Two familial cases of dissociation of saliva Lea levels and erythrocyte Lewis types.

Two familial cases in which the saliva Lea levels were seen to dissociate with the donors' red blood cell (RBC) Lewis types are reported. In case 1, the saliva from a donor with an RBC type of Le(a+b-) contained a low level of Lea antigen. A low Lea level was also observed in the saliva from this proband's father who has an RBC type of Le(a+b-). In case 2, the saliva from a donor with an RBC type of Le(a-b+) contained a high level of Lea antigen. High Lea levels were also present in the saliva of this proband's father and brothers with an RBC type of Le(a-b+).

Enzyme-Linked Immunosorbent Assay↗