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Biomedical subjects

K Shimura

Publications and source records attributed to K Shimura.

At least 37 records · Page 2Linked to original sources
PubMed1989

Enhancing effect of antitumor polysaccharide from Astragalus or Radix hedysarum on C3 cleavage production of macrophages in mice.

Effects of Astragalus polysaccharide (APS) and Radix hedysari polysaccharide (RHPS) on the third component of complement (C3) cleavage production of macrophages in ICR mouse were investigated by the immunofluorescent method. By two hours after intraperitoneal injection of 500 mg/kg of APS or RHPS, there was an obvious increase in the deposition of C3 on peritoneal macrophages. When APS or RHPS was injected 5 times (1 time/day), the proportion of C3 positive macrophages was more than that of 1-time injection. At the same time, the number of peritoneal macrophages also increased. Since C3 cleavage product occurred with the activation of C3, the results suggest that the immuno-potentiating action of APS and RHPS may be related to the activity of mouse complement C3.

Animals↗
PubMed1989

In vitro and in vivo interferon production in NOD mice.

The production of interferon-alpha/beta (INF-alpha/beta) and interferon gamma (IFN-gamma) in NOD and ICR mice was studied in vitro and in vivo. The in vitro IFN-alpha/beta production in the spleen cells of NOD mice, which were stimulated with either Newcastle disease virus (NDV), Sendai virus, poly(I:C) or lipopolysaccharide (LPS), was very similar to the IFN-alpha/beta production in the spleen cells of ICR mice. Contrastingly, the in vitro IFN-gamma production in the spleen cells of NOD mice, which were stimulated with either concanavalin A (Con A), phytohemagglutinin (PHA) or pokeweed mitogen (PWM), was greater than the IFN-gamma production in spleen cells of ICR mice. The in vivo IFN-alpha/beta production in NOD mice induced by NDV was also very similar to that in ICR mice, whereas the in vivo IFN-gamma production in the BCG-sensitized NOD mice, which was induced by purified protein derivative (PPD), was greater than that in the ICR mice. These results may indicate that NOD mice have abnormalities on the IFN-gamma production.

Animals↗
PubMed1988

Further evidence for the presence of a thiazoline ring in the isoleucylcysteine dipeptide intermediate in bacitracin biosynthesis.

Isoleucylcysteine dipeptide, a first intermediate peptide in bacitracin biosynthesis, was liberated from the enzyme protein and oxidized with manganese dioxide in dimethylsulfoxide. The resulting oxidation product was identified by thin-layer chromatography as 2-(2-methyl-l-oxobutyl)-thiazole-4-carboxylic acid which has been isolated from the hydrolysate of bacitracin F. This result shows that the intermediate dipeptide contains a thiazoline ring, and that the thiazoline ring is synthesized at the dipeptide stage in the process of peptide chain elongation in bacitracin biosynthesis. Improbability of non-enzymatic dehydrative cyclization of the dipeptide is discussed.

Bacitracin↗
PubMed1988

Immobilized anhydrochymotrypsin as a biospecific affinity adsorbent for the peptides produced by chymotryptic hydrolysis.

Anhydrochymotrypsin immobilized on Sepharose specifically adsorbed various peptides containing L-tryptophan, L-tyrosine, or L-phenylalanine residues at their carboxy-termini. These peptides correspond to the specific products of chymotryptic cleavage of polypeptides. A mixture of the chymotryptic peptides once adsorbed on the column could be effectively separated by eluting them with a pH gradient. This adsorbent, on the other hand, showed no substantial affinity toward the substrate-type peptides that contain the aromatic amino acid(s) within the peptide chain, or toward the C-terminal leucine peptides. By taking advantage of this unique property of anhydrochymotrypsin-Sepharose in combination with reversed-phase high-performance liquid chromatography, we have succeeded in separating the C-terminal peptides from chymotryptic digests of reduced and S-carboxymethylated bovine insulin and from tryptic digests from reduced and S-carboxymethylated Streptomyces subtilisin inhibitor.

Adsorption↗
PubMed1987

Affinophoresis of pea lectin and fava bean lectin with an anionic affinophore, bearing rho-aminophenyl-alpha-D-mannoside as an affinity ligand.

Affinophoresis is an electrophoretic separation technique for biological polymers with the aid of an affinophore, which is a macromolecular polyelectrolyte bearing affinity ligands. The affinophore migrates rapidly in an electric field, and consequently the electrophoretic mobility of molecules having an affinity for the ligand is specifically changed. An anionic affinophore-bearing mannosyl residue was synthesized for the affinophoresis of lectins. rho-Aminophenyl-alpha-D-mannopyranoside and aminomethanesulphonic acid were coupled to about one-tenth and one-fifth, respectively, of the carboxyl groups of succinyl-poly-L-lysine with an average degree of polymerization of 120 by the use of a water-soluble carbodiimide. Extracts of seeds of pea (Pisum sativum) or fava bean (Vicia fava) were subjected to two-dimensional agarose gel electrophoresis, in which the first dimension was ordinary agarose gel electrophoresis and the second dimension was affinophoresis with the affinophore. The separated proteins were stained with Coomassie Blue R250. The lectins in both seed extracts were separated from a diagonal line formed by other proteins in the extracts. About 10 ng of the separated pea lectin was detected on a nitrocellulose blot by immunostaining with a horseradish peroxidase-conjugated second antibody.

Aniline Compounds↗
PubMed1987

Affinophoresis in two-dimensional agarose gel electrophoresis: specific separation of biomolecules by a moving affinity ligand.

Affinophoresis is an electrophoretic separation technique for biomolecules which uses an affinophore. An affinophore is a macromolecular polyelectrolyte bearing affinity ligands. It migrates rapidly in an electric field, and consequently the electrophoretic mobility of molecules having affinity for the ligand is specifically changed. This technique has now been incorporated in two-dimensional agarose gel electrophoresis in a procedure which utilizes normal electrophoresis in the first dimension and affinophoresis in the second dimension. Proteins which do not have affinity for the ligand migrate to locations along a diagonal line passing through the origin, whereas proteins which have affinity are carried away from the line by the affinophore. Accordingly, molecules having affinity for the ligand can be readily assigned. Trypsins contained in Pronase and pancreatin were separated by this procedure using an affinophore bearing a competitive inhibitor for trypsin, benzamidine, on a polyanionic molecule (a polyacrylic acid derivative).

Affinity Labels↗
PubMed1987

Combination of high-performance affinity chromatography and specific detection of proenzyme applicable to the analysis of the fibrinolytic system of human plasma.

A procedure for the analysis of the fibrinolytic system in human blood was devised by combining high-performance affinity chromatography (HPAC) and specific detection of proenzyme. Components of the fibrinolytic system were separated by HPAC using Asahipak GS gel coupled with p-aminobenzamidine, and they were specifically detected by means of an on-line enzyme assay system. This system made it possible to quantitate not only Glu-plasminogen (Glu-Plg) but also Lys-plasminogen (Lys-Plg) in human plasma in a short time without pre-treatment. The effect of urokinase on the state of components of the fibrinolytic system in blood was studied. It was clearly shown that Lys-Plg is more susceptible to activation by urokinase than Glu-Plg (both in vitro and in vivo).

Chromatography, Affinity↗
PubMed1987

Goats as natural intermediate hosts of Hammondia hammondi.

The infectivity of Hammondia hammondi (the G-8 strain) to goats was studied to determine the origin of this strain, because it was originally isolated from feces of a cat fed goat muscles. No clinical signs except fever were observed in kids after oocyst inoculation. When cat fed muscles of these kids, the cats excreted oocysts. The prepatent period was 7 to 9 days and the patent period was 6 to 12 days. From these experiments it became clear that the G-8 strain was infectious to goats. The origin of this strain is very probably the goat, which thus is one of the natural intermediate hosts of H. hammondi.

Animals↗
PubMed1987

Further evidence for importance of the subunit combination of silk fibroin in its efficient secretion from the posterior silk gland cells.

A locus responsible for the Nd-s mutation of the silkworm, Bombyx mori, has been mapped very close to or within the fibroin light (L) chain gene on the 14th chromosome (Takei, F., K. Kimura, S. Mizuno, T. Yamamoto, and K. Shimura, 1984, Jpn. J. Genet., 59:307-313). A strain of B. mori carrying the homozygous Nd-sD mutation (Nd-sD/Nd-sD; Nd-sD is allelic to Nd-s) secretes less than 0.3% of fibroin into the lumen of the posterior silk gland compared with a strain carrying the homozygous wild-type alleles (+/+). The small amount of fibroin that is secreted in the Nd-sD/Nd-sD strain consists of the heavy (H) chain only and lacks the L chain, although the L chain mRNA and the proteins that are cross-reactable with the anti-L chain serum are present in the posterior silk gland cells. In the hybrid silkworm, Nd-sD/+, the H chain derived from either the Nd-sD or + allele forms disulfide linkage with the L chain derived from the + allele and these fibroins are secreted into the lumen with an equal efficiency, but the L chain derived from the Nd-sD allele remains in the cell unbound to the H chain. Some evidence suggesting structural abnormality of the L chain derived from the Nd-sD allele is presented. These results, together with the previous results on the effect of the H chain gene-linked Nd(2) mutation (Takei, F., F. Oyama, K. Kimura, A. Hyodo, S. Mizuno, and K. Shimura, 1984, J. Cell Biol., 99:2005-2010), strongly suggest that the H-L subunit combination of silk fibroin is important for its efficient secretion.

Alleles↗
PubMed1987

A rapid and sensitive analytical procedure for human plasminogen subspecies. Combination of high-performance affinity chromatography and specific monitoring of proenzymes.

Human plasminogens specifically separated by high-performance affinity chromatography were specifically detected by a newly devised, on-line monitoring system, in which the proenzymes were activated by urokinase and plasmin activity thus generated was assayed. Presence of Lys-plasminogen as a constituent in the blood was demonstrated by both chromatographic patterns and biochemical experiments. This system made it possible to estimate rapidly not only Glu-plasminogen but also Lys-plasminogen in the plasma without any pretreatment. Its utility as a tool for clinical analysis of fibrinolytic system was suggested.

Chromatography, High Pressure Liquid↗
PubMed1987

Anemia-inducing substance (AIS) in advanced cancer: inhibitory effect of AIS on the function of erythrocytes and immunocompetent cells.

The effects of anemia-inducing substance (AIS), found in the plasma of tumor-bearing subjects, on red blood cells (RBC) and cellular immunity were examined. The results obtained may be summarized as follows: 1) The osmotic resistance and the deformability of RBC were decreased in patients with terminal cancer. 2) Normal human RBC were made less deformable and their membrane was made fragile by treatment with cachectic plasma from those patients, and these changes in physical properties were irreversible. 3) Energy metabolism in RBC was affected by AIS, that is, ATP concentration and pyruvate kinase activity in RBC were lowered and transmembrane glucose influx was suppressed. 4) AIS was removed from cachectic plasma by repeated adsorption with normal RBC, and the inhibitory effect on cellular immunity was lessened as AIS was removed. 5) AIS was detected in cachectic RBC membrane, monocytes, and tumor tissue by indirect immunofluorescence assay using rabbit anti-AIS antibody prepared by us. These observations suggest strongly that tumor-derived AIS appears in the blood of patients with terminal cancer, shows cytotoxicity to RBC and immunologically competent cells, and plays a role in the pathogenesis of cancer cachexy.

Adenosine Triphosphate↗
PubMed1986

Transposable genetic element found in the 5'-flanking region of the fibroin H-chain gene in a genomic clone from the silkworm Bombyx mori.

A transposable genetic element was found in the 5'-flanking region of the fibroin H-chain gene in one of the genomic clones from the silkworm Bombyx mori. This element, named K-1.4, is about 1 X 4 X 10(3) base-pairs long, contains an open reading frame of only 225 base-pairs and has inverted repeats of 12 base-pairs at both ends. Duplication of three base-pairs seems to have occurred when this element was integrated into the silkworm genome. About 15 copies of K-1.4 are present per haploid genome of various silkworm strains. Genomic loci of some of these elements are different among different strains or even among individual offspring of the same parents. K-1.4 is present also in the genome of Bombyx mandarina. The K-1.4-related sequences are present in some species belonging to the family Saturniidae.

Animals↗