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Biomedical subjects

K Takeya

Publications and source records attributed to K Takeya.

At least 163 records · Page 9Linked to original sources
PubMed1979

Direct cytotoxicity against chicken erythrocytes in mice. II. Nature of immunoglobulin on cytotoxic T lymphocytes.

Direct cytotoxicity raised at an early interval after immunization with chicken erythrocytes (CRBC) has been ascribed to O-positive, immunoglobulin (Ig)-bearing lymphocytes. Cytotoxicity of such effector cells was not affected by trypsinization. Cytotoxity was reduced by the treatment of effector cells with anti-IgG serum and complement or by the addition of anti-IgG serum to culture medium for cytotoxicity test. When the effector cells were treated with trypsin before cytotoxicity test, such procedures with anti-IgG serum did not affect their cytotoxicity. Ig molecules on cytotoxic T lympohcytes may not be an essential element for antigen recognition. This explanation may be supported by the fact that cytotoxicity against CRBC could be raised in 600 rad irradiation, thymus-cell transferred mice in the absence of antibody production.

Animals↗
PubMed1979

Direct cytotoxicity against chicken erythrocytes in mice. III. Degrees of radiosensitivity and cross-reactivity of cytotoxicity, delayed hypersensitivity and antibody production.

Exposure to 600 rad of X-irradiation 3 h after primary immunization with chicken erythrocytes (CRBC) abolished the production of antibodies and the generation of killer T cells, but scarcely affected the induction of delayed footpad reactions. Exposure to irradiation 3 h after secondary immunization reduced only slightly the generation of killer T cells and reduced slightly or substantially the production of antibodies. Delayed reactions persisted for long periods after elicitation in irradiated, boosted mice. Cross-reactivity between CRBC and quail erythrocytes (QRBC) was very weak with respect to the cytotoxicity, antibody and delayed reaction raised after primary immunization. Those raised after secondary immunization with the homologous antigen showed some degrees of cross-reactivity to another antigen. The booster with QRBC in CRBC-primed mice augmented the response to CRBC with respsect to the induction of cytotoxicity and delayed footpad reaction, but only weakly affected the response with respect to the production of antibody. Therefore, effector cells of cytotoxicity and delayed footpad reaction showed greater degrees of cross-reactivity than antibody-producing cells during an anamnestic response. The cross-reactive response raised after secondary immunization was radioresistant with respect to cytotoxicity and delayed footpad reaction but radiosensitive with respect to antibody production. Cytoxicity to immunizing antigen was inhibited by the unlabelled homologous antigen. Cytotoxicity to a cross-reacting antigen was inhibited by the same cross-reacting antigen and also by an immunizing antigen. There may exist heterogeneous populations of cytotoxic lymphocytes with different abilities to recognize antigens.

Animals↗
PubMed1979

The specificity of potentiating effect of glutathione on the actions of bradykinin.

Potentiating effects of GSH, a physiologic kininase inhibitor on the bradykinin actions on (a) blood pressure responses of rabbits, (b) acute inflammatory response in rat's hind paws and (c) the isolated guinea-pig ileum contractions were examined among the combinations between various active agents and thiols. The potentiation of the hypotensive response to bradykinin by GSH was highly specific compared with the other experimental models (B and C). Throughout these three experiments, specific relation between GSH and bradykinin was consistently observed.

Animals↗
PubMed1979

Effect of stimulation and blockade of mononuclear phagocyte system on the delayed footpad reaction to SRBC in mice.

The delayed footpad reaction to sheep erythrocytes (SRBC) was studied in mice whose mononuclear phagocyte system (MPS) was blocked or stimulated. Colloidal carbon or carrageenan was used for the blockade of MPS and Corynebacterium parvum or diethylstilbestrol used for the stimulation. The optimal dose of SRBC for the induction of the delayed footpad reaction was lower in MPS-blocked mice than in non-treated mice, whereas a high dose of SRBC was required for the induction of the strongest delayed footpad reaction in MPS-stimulated mice. These results suggest that non-specific phagocytic function of MPS modulates subsequent immune responses after administration of antigens.

Animals↗
PubMed1979

Immune response to syngeneic or autologous testicular cells in mice. I. Augmented delayed footpad reaction in cyclophosphamide-treated mice.

A delayed footpad reaction against syngeneic or autologous testicular cells was detected in mice of inbred C57BL/6, AKR and C3H/He strains. The reaction was only provoked to a measurable level if the immunization was preceded by treatment with cyclophosphamide (CY). Footpad reaction was strongest on day 6 after immunization and was detected in both male and female mice. It was found that the reaction was elicited not only with the immunizing antigen, but also with allogeneic or xenogeneic testicular antigen in mice immunized with syngeneic testicular cells.

Animals↗
PubMed1979

Augmented resistance to Listeria monocytogenes in mice at an early stage of aging.

Protective mechanisms against Listeria monocytogenes were studied in young (3-month-old) and old (15-month-old) mice of C3H/He strain. Cumulative mortality rates of old mice were lower than those of young mice after intravenous inoculation of the same doses of bacteria. The numbers of bacteria in the liver and spleen on days 1 and 3 were larger in young than old mice. Bacterial growth at this stage of infection is suppressed by accumulation of non-immune macrophages. On day 7, however, the numbers of bacteria in the liver were smaller in young than old mice. Bacterial elimination at this stage depends upon immune macrophages. These results suggest that the enhanced resistance to lethal effects of bacteria in old mice may be ascribed to activation of non-immune macrophages in the presence of depressed capacities to raise cell-mediated immunity.

Aging↗
PubMed1978

Physicochemical and biological properties of mycobacteriocin M12 produced by Mycobacterium smegmatis ATCC 25855.

A mycobacteriocin (M12) produced by Mycobacterium smegmatic ATCC 25855 was partially purified by ammonium sulphate precipitation followed by DEAE-cellulose chromatography and Sephadex G100 chromatography. Production of M12 was maximal when bacteria were harvested after 3 d cultivation in liquid medium and disrupted by sonication. The molecular weight of M12, estimated by Sephadex G100 chromatograpy, was about 85000. M12 was sensitive to proteolytic enzymes but resistant to DNAase and RNAase, and was relatively stable to heat treatment, sonication, ultraviolet irradiation and pH over the range 4 to 8. When sensitive bacteria were exposed to the mycobacteriocin, the number of viable cells began to decrease after about 6 h incubation. The killing curve of M12 thus appeared to be a multiple-hit curve. Electron microscopic observation revealed that the mycobacteriocin induced morphological changes in the cells; these were partial loss of ribosomes, enlargement of lipoidal inclusion bodies and thickening of the cell envelope. The activity spectrum of M12 was restricted to the genus Mycobacterium.

Bacteria↗
PubMed1978

Proliferation of hemolysin-plaque-forming cells in nude mice and normal littermates subjected to antigenic competition.

The increase of PFC per spleen and the development of hemolytic foci were examined to clarify the patterns of clonal expansion of B-lymphocytes in athymic nude mice (nu/nu) and normal littermates (nu/+) subjected to the procedure for antigenic competition between horse erythrocytes (HRBC) and sheep erythrocytes (SRBC). In normal littermates without pretreatment with HRBC, a small number of PFC and hemolytic foci of small size were detected 2-days after the challenge with SRBC. The number of PFC increased progressively from day 2 to day 4, and hemolytic foci increased in the number and size during the period. In nude mice, a small number of PVFC were detected on day 2 and the number increased only slightly from day 2 to day 4. No large hemolytic foci were detected during the period. In normal littermates subjected to the procedure for antigenic competition, the patterns of increase of PFC and development of hemolytic foci were similar to those in nude mice. In nude mice, the procedure for antigenic competition exerted almost no effect on the patterns.

Animals↗
PubMed1978

Effects of cyclophosphamide on the expression and induction of delayed hypersensitivity.

Erythematous delayed reactions without induration, presumably assigned to Jones-Mote type, were characterized by the resistance to treatment with cyclophosphamide (CY) before elicitation or immunization in guinea pigs immunized with BGG in IFA or CFA. CY-treatment before elicitation converted delayed erythematous reactions from negative to positive at late intervals after immunization with BGG in IFA. Such a treatment augmented erythematous delayed reactions in animals immunized with BGG in CFA, but abolished induration at the reaction sites. CY-treatment before elicitation or immunization reduced the numbers of basophils at the reaction sites, although erythematous delayed reactions were augmented. Effector T cells responsible for delayed erythematous reaction without induration appear to persist for a long period of time after immunization in the presence of antibody production or tuberculin hypersensitivity and the expression of their function may be inhibited by suppressive mechanisms.

Animals↗
PubMed1978

Purification and the ultrastructure of a bacteriocin produced from Shigella sonnei strain 100052.

A bacteriocin produced by strain 100052 of Shigella sonnei (shigellacin 52) was purified about 80-fold from a mitomycin C-induced culture supernatant. The purified preparation gave a single band on sodium dodecyl sulfate-gel electrophoresis with an approximate molecular weight of 10,000. The negatively stained electron micrograph of the purified bacteriocin preparation revealed the existence of three different particles. They were a small cylindrical tube (4.2 by 6.0 nm), a ring-shaped particle and a filamentous structure. The molecular weight calculated from the shape of the small tube was approximately 50,000. The latter two particles appeared to be constructed from subunits which were morphologically similar to the cylindrical tube. These results suggested that the morphological subunit of shigellacin 52 consisted of five chemical subunits with molecular weights of 10,000 each, and it assembled into two types of polymers, a ring-shaped particle and a filamentous structure, which seemed to be the main components of the purified shigellacin 52 preparation.

Bacteriocins↗
PubMed1978

Experimental models for prevention of graft-versus-host reaction in bone marrow transfusion. II. Inability to prevent graft-versus-host reaction in an H-2 identical combination.

Splenomegaly was strong in the degree and continued for a long period of time in adult F1 hybrids between AKR (H-2k) and C3H/He (H-2k) mice after transfer of spleen cells from normal C3H/He mice. In spleen cells of such F1 recipients, cytotoxicity was detected by an in vivo neutralization test using methylcholanthrene-induced sarcoma or AKR origin as target cells. All of newborn F1 recipients died within 17 days after cell transfer. Induction of splenomegaly and cytotoxicity was not prevented by repeated pretreatments of donors with sonicated AKR spleen cells in saline, which suppressed completely such phenomena of graft-versus-host reaction in an H-2 nonidentical combination. Induction of cytotoxicity in the spleen of F1 recipients was not prevented by a pretreatment of donors with AKR spleen cells in complete Freund's adjuvant, which suppressed the induction of cytotoxicity in an H-2 nonidentical combination. Graft-versus-host reaction appears to be stronger in a combination between parental strains of which major histocompatibility antigens were identical.

Animals↗
PubMed1978

Experimental models for prevention of graft-versus-host reaction in bone marrow transfution. III. Reversible and irreversible differentiation of lymphocytes destined for cytotoxicity to effector cells for splenomegaly.

When lymphoid cells were obtained from AKR donors 12 h after a treatment with C57BL/L cells in complete Freund's adjuvant and transferred to (AKR X C57BL/6) F1 mice, splenomegaly in F1 recipients was augmented but cytotoxicity was suppressed. The suppression of cytotoxicity was antigen-specific. When cell transfer was carried out at stages as early as 3 or 6 h after the treatment of donors, cytotoxicity was enhanced but splenomegaly was suppressed. Irreversible deviation of immune response from the generation of cytotoxicity to the development of splenomegaly appears to occur within 12 h after such a treatment of donors.

Bone Marrow Transplantation↗
PubMed1978

Relationships between IgE antibody production and other immune responses. II. Effect of thymectomy at various times after birth.

Mice were subjected to thymectomy at various times after birth and immunized with ovalbumin in aluminum hydroxide gel at 4 or 8 weeks of age. The capacities to produce IgE, IgM and IgG antibodies were abolished by thymectomy carried out within 48 h after birth. The capacity to produce IgE antibody was not affected by thymectomy at 7 days or later, whereas the capacities to produce IgM and IgG antibodies were reduced by thymectomy carried out at 4 weeks of age.

Animals↗