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Biomedical subjects

S Ogata

Publications and source records attributed to S Ogata.

At least 235 records · Page 13Linked to original sources
PubMed1981

Comparison of [3H]glucosamine-labeled glycoproteins from human renal cancer and normal kidney epithelial cell cultures by two-dimensional polyacrylamide gel electrophoresis.

Two-dimensional polyacrylamide gel electrophoresis has been used to compare the Nonidet P-40 soluble, [3H]glucosamine-labeled glycoproteins of human kidney cancer cell lines and short-term cultures of normal kidney epithelia. Two pairs of autologous combinations of tumor and normal cells and also six other cancer lines and four normal cultures were examined. Because autologous cells could be compared, possible differences due to allogeneic variations could be eliminated. The electrophoretic patterns given by tumor and normal cells were extremely similar. Nevertheless, more than 10 differences could be recognized when randomly selected combinations of cancer and normal cells were examined in detail. Of these differences, however, only one was consistently found in all possible combinations of cancer and normal cells. Cancer cells had three prominent components of molecular weight 27,500 and pIs of 5.7, 5.3, and 4.9, respectively. Normal cells have a fainter and different constellation of spots in this region, with the more acid component (pI 4.9) being absent (or barely detectable). The pattern of fetal kidney cells resembled that given by normal adult kidney.

Cell Line↗
PubMed1981

Cell surface antigens of human renal cancer defined by mouse monoclonal antibodies: identification of tissue-specific kidney glycoproteins.

Seventeen monoclonal antibodies derived from fusions with spleen cells of mice immunized with established culture lines of renal cancers identified nine cell-surface antigenic systems. Six of the systems (gp160, S25, gp120r, gp120nr, gp115, and V1) represent antigens not previously described. The other three systems are related to HLA-A, -B, and -C heavy chain and A and B blood group antigens. The most restricted of the newly described antigens are gp160, S25, and gp120r. These determinants are found only on cells of renal origin, both normal and malignant, and represent differentiation antigens of human kidney. In addition to the difference in the molecular weight of two of these antigens, gp160, S25, and gp120r can be distinguished on the basis of differential expression on a panel of cultured renal cancers and normal kidney epithelium and fetal kidney cells. Glycoproteins bearing gp120r share a determinant with renal gp120nr (as indicated by sequential precipitations with monoclonal antibodies that detect gp120r and gp120nr), but gp120nr is found on a broader range of cell types, including fibroblasts and cell lines derived from lung, bladder, and colon cancers. The two other new systems, gp115 and V1, have characteristics of broadly occurring differentiation antigens but can be distinguished from each other and from gp120nr by differences in molecular weight, heat stability (V1 is a heat-stable determinant), and differential expression on cell types of diverse origin.

ABO Blood-Group System↗
PubMed1981

Multiple forms of rat-serum alpha 1-protease inhibitor. Involvement of sialic acid in the multiplicity of three original forms.

alpha 1-Protease inhibitor was purified from rat serum by two different methods, of which an immunoaffinity method should be preferentially used to obtain all of the multiple forms. The protein thus obtained showed a single protein band in dodecylsulphate/polyacrylamide gel electrophoresis corresponding to a molecular weight of 54000, and contained 13.2% carbohydrate by weight. By column isoelectric focusing in a pH 3.5-5.0 gradient the purified alpha 1-protease inhibitor was separated into five forms with pI values from 4.3-4.7. The amino acid composition of each form was identical, while sialic acid content was significantly different from each other. The most acidic form contained 6.7 residues/molecule, the most basic form, 5.1 residues/molecule, and three forms between them showed proportionally intermediate values between the two. When alpha 1-protease inhibitor was treated with neuraminidase, the five forms were converted finally into three major forms with pI values of 5.3-5.7. In addition, the major form (band 3) of the inhibitor was also converted into three forms after complete removal of sialic acid. These results suggest that alpha 1-protease inhibitor originally exists as three forms with different charges, possibly due to modification of amino acids which might not be detectable by the amino acid composition analysis in the present study. A possible explanation was presented for involvement of sialic acid in appearance of multiple forms originating from three parental forms.

Amino Acids↗
PubMed1981

Specific Lysogenicity in Streptomyces azureus.

Slope (or plate) cultures of thiostrepton-producing Streptomyces azureus (ATCC 14921) often showed spontaneously developing plaques. Plaques increased in number during serial subcultures. The production of aerial mycelia and sporulating aerial hyphae was interrupted by the overlapping plaques, whereas the growth of substrate mycelia continued in the plaques. These abnormal (eroded) cultures were easily restored to their normal conditions once they were passed through liquid cultures under shaking conditions. A few phage particles were found in the plaques, together with some headless tails and numerous tail tips which formed a hexagonal crystal or a large crystal mass when viewed in an electron microscope. No lytic phenomenon and no phage production were found in the liquid cultures, although all mycelia and spores harbored phage-producing abilities. It was also found that the propagation of phages was successful in solid culture, but not in liquid culture. The whole phage was named SAt2, which belongs to group B of Bradley's morphological classification. From these results, it is considered that S. azureus is lysogenic with temperate phage SAt2, of which virulent mutants are able to infect the aerial mycelia and sporulating hyphae of their lysogenic host.

Journal Article↗
PubMed1980

Morphological changes during conversion of Clostridium saccharoperbutylacetonicum to protoplasts by sucrose-induced autolysis.

When exponentially growing cells of Clostridium saccharoperbutylacetonicum (ATCC 13564) were exposed to hypertonic concentrations of sucrose (0.3--0.5 M), rapid degradation of the cell wall occurred (sucrose-induced autolysis). The morphological changes from the original rod-shaped cells to protoplasts during the sucrose-induced autolysis were investigated by phase contrast and electron microscopy. When the cells were autolysed in the sucrose solution (0.35 M), each cell began to swell at the middle or at one pole and then formed a small bulb at the swollen part. The bulk consisted of the cytoplasm which was enveloped by the plasma membrane and extruded from the small gap produced by the degradation of the cell wall. The bulb gradually enlarged as lysis progressed, and finally became a protoplast which had no cell wall. The large pre-division cell frequently formed the bulb at the middle (septal site), while the small post-division cell formed the bulb at the pole.

Autolysis↗
PubMed1979

Antigenicity of protein and lipopolysaccharide from Yersinia enterocolitica.

The rabbits infected intravenously with viable Yersinia enterocolitica (Y.e.) produced the precipitating antibodies against a protein component as well as lipopolysaccharide of the organism. The production of the precipitins against protein antigen persisted for a long period of time even after the O-agglutinins had disappeared. The rabbits infected orally with the organism produced only the precipitins against protein antigen, and the amount of the antibody was equal to or greater than that of intravenous infection. The same precipitins that rabbits produced were detected even in human patients with yersiniosis showing O-agglutinin titers as low as less than or equal to 1:20. The antibody titers of mice infected with Y.e. were markedly lower than those of rabbits.

Agglutination Tests↗
PubMed1978

Effects of homologous O-antibody on host responses to lipopolysaccharide from Yersinia enterocolitica: neutralization of its pyrogenicity.

The pyrogenic activity of lipopolysaccharide (LPS) obtained from Yersinia enterocolitica was neutralized by the homologous O-antiserum at the optimal antigen/antibody ratio. The level of neutralization in either antigen excess or extreme antibody excess was significantly lower than that at the optimal ratio. These facts suggested that the structure of the so-called "lattice" of LPS/antibody complex might influence the neutralization of pyrogenic activity. Moreover, when LPS was gradually added to the antiserum to reach the optimal antigen/antibody ratio, the pyrogenic activity of LPS was only slightly neutralized by the antibody. The similar event to Danysz phenomenon that has been known in the diphtheria toxin-antitoxin system was also observed in the LPS-anti-LPS system.

Animals↗
PubMed1975

Fractionation of glycopeptides by affinity column chromatography on concanavalin A-sepharose.

Using [3H]-labeled oligosaccharides, we found that the presence of at least two alpha-mannosyl residues with free hydroxyl groups at C-3, 4, and 6 is required for oligosaccharides to be related by a concanavalin A-Sepharose column. This finding is also applicable to N-[14C]acetylated glycopeptides. Thus, the concanavalin A-Sepharose column might become a useful tool for structural studies of glycopeptides and oligosaccharides and for their fractionation. Glycopeptides prepared from the trypsinate of rat fibroblasts, which has been purified by paper electrophoresis, were further separated into two fractions by chromatography on a concanavalin A-Sepharose column.

Acetamides↗