Search PubMed⌕ Search

Biomedical subjects

C T Chou

Publications and source records attributed to C T Chou.

87 records · Page 5Linked to original sources
PubMed1976

Rabbit lymphoid cells. I. T-cell mitogens, cell volume and adherence properties as probes for cellular heterogeneity.

Thymus-derived cell populations were characterized by sedimentation velocity in the Earth's gravitational field, by adherence properties, and in terms of the thymus-specific antigen RTLA. T cells, responding to mitogens, could be shown to be a subpopulation of RTLA-bearing cells and to have a relatively large volume. The size distribution of mitogen-responsive cells from different individuals showed some variation, but in general large spleen cells took up less thymidine per 10(6) cells than did large cells from other lymphoid organs. Upon stimulation with concanavalin A (con A) small popliteal lymph node cells took up more thymidine per 10(6) cells than did small thymus cells. The corresponding small cells of mesenteric lymph node and spleen took up intermediate quantities of thymidine. Thymus-derived cells that were resistant to complement-mediated cell kill with RTLA antiserum showed greater responsiveness to con A than did the original cell preparations. Non-adherent cells incorporated more thymidine when stimulated with phytohaemagglutinin (PHA) than when they were stimulated with con A. Lightly adherent cells were relatively more responsive to con A stimulation and firmly adherent cells were less responsive to both. The findings were discussed in terms of the density of RTLA on the membranes of T cells. In adherence and in sedimentation velocity fractionation, the relative yield of nucleated cells always exceeded the yield of PHA- and con A-responsive cells. The differential separation of mitogen responsive and of co-operating cells were considered as a possible cause of this deficit.

Animals↗
PubMed1976

Rabbit lymphoid cells. II. Anti-allotype antisera, lipopolysaccharide and other bacterial and fungal mitogens as probes for the identification of B-cell subpopulations.

Removal of adherent cells or complement-mediated killing of rabbit thymus lymphocyte antigen (BTLA) bearing rabbit T lymphocytes did not abolish the responsiveness (increased thymidine incorporation) of lymphoid cells to antibody against immunoglobulin allotype, Nocardia water-soluble mitogen (NWSM), pneumococcal polysaccharide SIII (PPSIII), S. abortus lipopolysaccharide (LPS), lipid A conjugated to bovine serum albumin and a crude preparation containing C polysaccharide from the cell wall of Diplococcus pneumoniae. Isologous and heterologous antisera, directed against different portions of the Ig receptor, differed in their capacity to enhance thymidine incorporation. The difference in mitogenicity of these antisera was discussed in terms of the accessibility of cell-bound immunoglobulin receptor sites. Spleen cells, responsive to anti-allotype (Ab4) antiserum and B-cell mitogens, NWSM and PPSIII, were characterized by velocity sedimentation. The mean volume of NWSM- and PPSIII-responsive cells was larger than that of the cells responsive to anti-allotype antiserum. Fractionation of spleen cells on glass bead columns yielded a population of non-adherent cells which were two to six times as responsive to anti-Ab4 antiserum as the original spleen cell suspension. The responsiveness of peripheral blood lymphocytes to anti-Ab4 antiserum was significantly greater than that of spleen cells. On the other hand, spleen cells were more responsive to PPSIII than were cells from the peripheral blood, the popliteal and the mesenteric lymph nodes.

Animals↗
PubMed1975

Volume, adherence properties, membrane antigens and mitogen responsiveness of rabbit lymphoid cell subpopulations.

Subpopulations of rabbit spleen cells which respond to T and B mitogens, respectively, can be distinguished by sedimentation velocity in the earth's gravitational field. T cell subpopulations which differed in their responsiveness to Con A and to PHA could be identified by differences in adherence properties and by their sensitivity to complement mediated cell kill with RTLA-antiserum.

Absorption↗
PubMed1967

Cells as antigen carriers and as immunoglobulin producers. Synthesis of antibody and allogeneic immunoglobulin after transfer of antigen-treated cells to newborn rabbits.

The injection into newborn rabbits of a small quantity of human albumin, associated with red blood corpuscles or nucleated rabbit cells, induces an antibody response in the majority of animals, whereas the same quantity of antigen in solution fails to stimulate antibody formation or induces tolerance. The promoting capacity of the cells depends on attachment of antigen to them. The antibody produced after the injection of albumin, associated with nucleated cells, is of recipient origin. However, immunoglobulin carrying the marker of donor cells can be demonstrated in the recipient animals, and may reach serum concentrations similar to those normally present in animals which are heterozygous with respect to the marker. It appears that the antibody-promoting function and the synthetic capacity for allotype are quite distinct and that the period required for allotype formation is very short with mononuclear peritoneal exudate cells and is very much longer with cells from the thymus. The capacity of cells from lymph nodes for sustained allotype formation is less than that of thymus cells but greater than that of mononuclear peritoneal exudate cells.

Animals↗
PubMedDate not supplied

Rabbit B spleen lymphocytes and macrophages as accessory cells in T-cell activation by mitogens.

The enhancement of the response of T cells to concanavalin A (ConA) and phtyohaemagglutinin (PHA) by macrophages has been shown in most species, whereas the accessory role of B cells has been only described in studies using human or rabbit lymphocytes. In rabbit, the accessory activity is confined to a subpopulation of B lymphocytes: the majority of B cells have sedimentation velocity of 2.5 to 4 mm/h, whereas the maximum of the accessory activity is found among the B cells, sedimenting with a velocity of 3.5 to 8 mm/h; B cells sedimenting between 1 and 3.5 mm/h have only a very weak accessory activity. Splenic adherent and/or phagocytic spleen cells may contribute additional augmentation of the response of T cells to ConA, since other macrophages (peritoneal and alveolar) are able to increase the ConA response to spleen T cells.

Animals↗
PubMedDate not supplied

Enterobacterial antibodies in Chinese patients with rheumatoid arthritis and ankylosing spondylitis.

OBJECTIVE: To study the role of microbial infection in rheumatic diseases. METHODS: Sera from 39 Chinese patients with rheumatoid arthritis (RA), 52 patients with ankylosing spondylitis (AS) and 51 healthy subjects (HS) were examined for IgG, IgA, and IgM class antibodies against Proteus mirabilis, Escherichia coli, Campylobacter jejuni, Salmonella typhimurium and enteritidis, Yersinia enterocolitica, and Klebsiella pneumoniae (capsular serotypes 31 and 43), using an enzyme-linked immunosorbent assay. RESULTS: In patients with RA, IgA class antibodies against all bacterial strains used as the antigen were increased when compared to healthy controls. In patients with AS, significantly elevated IgA levels were observed against Campylobacter and Klebsiella K43. IgM class antibodies were less frequently elevated in RA and in AS than IgA class antibodies. In RA patients, IgG antibodies against Klebsiella K43 and Proteus were significantly increased. No differences were observed in IgG class antibodies between AS patients and healthy controls. CONCLUSION: Increases in serum bacterial antibodies in RA and AS suggest that in both diseases stimulation of the intestinal immune system by enterobacteria may have a role. However, the question whether this phenomenon is due to increased intestinal permeability and/or represents cross reactions between different enterobacteria remains open.

Antibodies, Bacterial↗