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Biomedical subjects

A Takada

Publications and source records attributed to A Takada.

At least 487 records · Page 27Linked to original sources
PubMed1977

[Trypsin inhibitors in human urine (author's transl)].

By using ammonium sulfate, Arg-Sepharose and gel filtration, an urinary trypsin inhibitor (UTI) with molecular weight of 67,000 (UTI7) was isolated from normal human urine. The yield of UTI7 was about 3,200 U per liter of urine. When urine was acidified, an uropepsin-like substance was activated which caused molecular weight change of UTI7. New UTIs had molecular weight of 45,000 and 22,000 (UTI4-5 and UTI-2-2), respectively. These inhibitors showed a strong effect on trypsin, alpha--chymotrypsin and lesser extent on plasmin and elastase, but had no effect on esterolytic activity on thrombin and the first components of complement Cls an Clr.

Electrophoresis, Polyacrylamide Gel↗
PubMed1976

Membrane characteristics of established human T- and B-cell lines. Cross-reactivity of human T-antigenic determinants with peripheral lymphocytes of non-human primates and the presence of MLC antigens on cultured T-cell lines.

Human T-cell lines (MOLT-4 and SOMMER-T) were injected into rabbits and monkeys (stumptail and squirrel monkeys). Rabbit anti-MOLT serum was absorbed with human liver and cultured B cells. Absorbed anti-MOLT serum was cytotoxic to lymphocytes of baboons and stumptail monkeys. Rabbit anti-MOLT and SOMMER-T sera after absorption with liver and B cell showed florescent ring formation in baboon and stumptail lymphocytes by using immunoflurescence techniques. On the other hand, antisera against MOLT and SOMMER-T cells in stumptail and squirrel monkeys were not only cytotoxic to MOLT and SOMMER-T cells, but also to other T-cell lines, CCRF-CEM and CCRF-HSB-2 cells. Cultured B-cell lines stimulated allogeneic and xenogeneic (rabbit and monkeys) lymphocytes far better than cultured T-cells lines did. T-cell lines, CCRF-HSB-2 and SOMMER-T (number 8402), gave small but significant stimulation to allogenic lymphocytes especially in the presence of foetal calf serum. MOLT-4B failed to stimulatie allogeneic lymphocytes. When lymphocytes of non-human primates and rabbit were cultured with human B- and T-cell lines in the presence of foetal calf serum, CCRF-HSB-2 and SOMMER-T cells stimulated xenogeneic lymphocytes of rabbit, squirrel monkey and stumptail monkey. MOLT-4 cells stimulated lymphocytes of baboon to some extent. These results indicate that although cultured B-cell lines had more mixed lyphocyte reaction (MLR) stimulating structure than T-cell lines, the latter still maintained some stimulating structure on the membrances.

Animals↗
PubMed1976

Lymphokine-like factors produced by human lymphoid cell lines with B or T cell surface markers.

In the present series of experiments we examined the ability of eight continuous cell lines derived from human lymphocytes to release lymphokines into their culture media. We have demonstrated that all could produce a macrophage migration inhibitory factor and a neutrophil chemotactic factor. This ability was independent of the B or T cell origin of the cell lines. As a further extension of previous reports, we report that the migration inhibitory effect does not seem to be due to cytotoxic effects as judged by trypan blue exclusion studies, and more important by the demonstration that the inhibition is reversible. The demonstration that neutrophil chemotactic activity is removable by treatment with a previously described and characterized anti-lymphokine antiserum suggests that this factor may be chemically similar to some of the lymphokines (migration inhibitory factor or chemotactic factor for macrophages) produced by antigen-activated guinea pig lymphocyte cultures. The failure to effect similar removal or inactivation of the macrophage migration inhibitory factor may simply reflect greater interspecies heterogeneity in this factor, or more interestingly, that this does not correspond to "classic" MIF. These results extend previous observations by defining further the capacity of lymphoid cell lines in continuous culture to produce mediators and by characterizing their relationship to conventional lymphokines produced by antigen or mitogen-activated lymphocytes.

B-Lymphocytes↗
PubMed1975

Antigenic determinants common to established human B-cell lines, but not shared by human T-cell lines (molt and sommer).

Rabbits were immunized with two kinds of human B-cell lines (SOMMER-B, and RPMI number 1788 cells) to get anti-B-cell sera. Sera were absorbed with human red blood cells, human liver, human brain and human T cells (MOLT-4 and SOMMER-T cells). Cytotoxicity of absorbed sera was not only tested against B cells which were used for immunization but also tested against unrelated B cells, including B35M cells derived from Burkitt lymphoma specimens. Results indicated that established human B cells had antigenic determinants which were shared with allogeneic human B cells, but not shared with non-lymphoid cells or tissues, nor with extablished human T cells.

Absorption↗
PubMed1974

Immunological functions of human T-lymphoid cell line (MOLT). I. Release of immunosuppressive factors from the mixture of MOLT-4 cells and sheep red blood cells.

A short term incubation of the mixture of established human T-lymphoid cells (MOLT) and sheep red blood cells (SRBC) resulted in the release of factors which nonspecifically suppressed the response of mouse spleen cells against heterologous erythrocytes in vitro. Neither human B-cell line (RPMI 1788), nor the supernate of MOLT cell suspension in the absence of SRBC had such suppressive effects. The supernate of the mixture of MOLT cells with chicken red blood cells (CRBC) did not suppress either anti-CRBC or anti-SRBC responses of mouse spleen cells. Since CRBC did not form rosettes with MOLT cells, it is suspected that the origin of the production of these factors might be MOLT cells forming SRBC rosettes. Some of these factors are dialysable.

Animals↗