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Biomedical subjects

K Hisatsune

Publications and source records attributed to K Hisatsune.

At least 109 records · Page 6Linked to original sources
PubMed1977

Immunological properties of Vibrio cholerae lipopolysaccharides.

Immunological effects of wall lipopolysaccharide (LPS) preparations obtained from Vibrio cholerae Inaba 569B, Ogawa NIH 41 and NAG 4715 strains by the hot phenol-water procedure were examined in mice. Although these LPS lack KDO, which are basic components of the core region of most gram-negative LPS, they still have potencies as B-cell mitogens, adjuvants, immunosuppressants, polyclonal B-cell activators and phagocytic stimulants for macrophages. The activities of these V. cholerae LPS on murine immune system seemed to be weaker than those of Salmonella typhimurium LT2-LPS. Among these V. cholerae LPS, NAG 4715-LPS showed the strongest mitogenic activity and phagocytic stimulation, while the potencies of this NAG 4715-LPS for the induction of polyclonal B cell activation, adjuvant effects and immunosuppression did not seem to be greater to those of the other LPS.

Animals↗
PubMed1975

[Study on the age-hardenable silver alloy (3 rd report). III. On the ageing process of dental Ag-Pd-Cu-Au alloy (author's transl)].

The precipitation hardening process of a dental silver base alloy, Ag-28 Pd-10 Cu-12 wt % Au, was studied by means of X-ray diffraction, hardness measurement and metallographic observations. After solution treatment at 900 degrees C for 30 min, specimens were subjected to anisothermal annealing at the rate of 1 degrees C/min. PdCu ordered phase and alpha2 solid solution (Ag rich phase) precipitated hetelogeneously at the grain boundaries and then grew up into each grain. Drastic increase in hardness was recognized with the spread of nodular region. Electron microscopic observation of these precipitates showed very fine lamellar structure. It is concluded that the age hardening of this alloy could be attributed to this grain boundary precipitation and the softening at the overaged stage to the second grain boundary reaction which produced very coarse lamellar structure.

Copper↗
PubMed1970

Bacteriolytic enzymes from Staphylococcus aureus. Purification of an endo-beta-N-acetylglucosaminidase.

On cultivation of Staphylococcus aureus in a complex liquid medium, bacteriolytic activity is found extracellularly. The maximal amount was found at the end of the exponential growth phase in batch culture, but in continuous culture run under similar conditions the yield was doubled. Isoelectric focusing of dialysed crude culture supernatants showed that the bacteriolytic activity of all four strains studied (M18, 524, Wood 46 and Duncan) was heterogeneous. The most alkaline peak of activity (isoelectric point 9.5+/-0.1) was assayed against Micrococcus lysodeikticus turbidimetrically. This bacteriolytic activity was purified more than 70-fold after continuous dialysis by adsorption on CM-Sephadex, precipitation with ethanol, heat purification, isoelectric focusing and Sephadex G-100 chromatography. The purified enzyme (isoelectric point 9.6+/-0.1) was found to give a single band on polyacrylamide-gel and cellulose acetate electrophoresis and was devoid of all 14 staphylococcal enzymes and toxins assayed for. The molecular weight is 70000+/-5000 as estimated by Sephadex G-100 and G-200 chromatography. The marked instability of the partially and highly purified enzyme was investigated. The mode of action and some properties of this enzyme are given in the following papers (Wadström & Hisatsune, 1970; Wadström, 1970). These results indicate that this extracellular enzyme which is produced by several strains of S. aureus is not a ;lysozyme' (endo-beta-N-acetylmuramidase) as previously suggested, but an endo-beta-N-acetylglucosaminidase.

Adsorption↗
PubMed1970

Bacteriolytic enzymes from Staphylococcus aureus. Specificity of ction of endo-beta-N-acetylglucosaminidase.

The bacteriolytic enzyme with an isoelectric point of 9.5 that is produced by all strains of Staphylococcus aureus investigated was purified from strain M18 (Wadström & Hisatsune, 1970). This enzyme released reducing groups from cell walls of Micrococcus lysodeikticus and was thus shown to be a bacteriolytic hexosaminidase. Although dinitrophenylation and acid hydrolysis of cell walls hydrolysed by a partially purified enzyme gave DNP-alanine and DNP-glycine from staphylococcal peptidoglycan, which indicated the presence of a peptidase and probably also an N-acetylmuramyl-l-alanine amidase, hydrolysis of cell walls by the extensively purified enzyme did not give any DNP-amino acids. The enzyme digest was purified by Amberlite CG-120 and Sephadex G-10 chromatography. Reduction by sodium borohydride of the disaccharide obtained was followed by acid hydrolysis and paper chromatography. Glucosamine completely disappeared after this treatment and a new spot identical with glucosaminitol appeared. The muramic acid spot remained unchanged. The purified enzyme was found to be devoid of exo-beta-N-acetylglucosaminidase activity. These results are compatible with the action of a bacteriolytic endo-beta-N-acetylglucosaminidase. It is also proposed that this enzyme is probably identical with the staphylococcal lysozyme. The mode of action of this has not previously been investigated.

Alanine↗
PubMed1970

Cell Wall Component Which Affects the Ability of Serum to Promote Phagocytosis and Killing of Staphylococcus aureus.

The role of various cell wall components of nonencapsulated Staphylococcus aureus in phagocytosis and killing was studied. Adsorption of human serum with S. aureus cell walls, or trypsin-digested cell walls, reduced the rate of phagocytosis and killing of S. aureus by human-blood leukocytes when compared to unadsorbed serum. When the various components of the cell walls were used for adsorption, only the intact mucopeptide was found to remove these factors. Products of digestion of this mucopeptide with several enzymes were found to be inactive when used for adsorption of human serum. Other components tested were teichoic acids alpha, beta, and combinations of both and protein A. When used in equivalent amounts, these were found to have no effect on the removal of serum factors necessary for phagocytosis and intracellular killing of S. aureus.

Journal Article↗