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Biomedical subjects

C T Chou

Publications and source records attributed to C T Chou.

At least 73 records · Page 4Linked to original sources
PubMed1986

Modification of a screening technique to evaluate systemic lupus erythematosus in a Chinese population in Taiwan.

Several recent reports have suggested that systemic lupus erythematosus (SLE) may be more common in Chinese than in other populations. We have revised a validated questionnaire devised by Liang, et al, for use in Chinese and surveyed 1,836 people in a community survey and 2,000 students at a girls college in Taipei, Taiwan. This constitutes the largest population yet surveyed with this technique. Only 1 case of probable SLE was identified. Since many apparent normals gave the 3 positive responses suggested to require ANA screening, continued effort should be directed toward increasing survey specificity before the massive population surveys needed to calculate accurate prevalence.

Antibodies, Antinuclear↗
PubMed1985

Musculoskeletal manifestations in hemodialysis patients.

One hundred and two consecutive patients receiving maintenance hemodialysis were interviewed and examined to analyze their musculoskeletal problems. Radiographic abnormalities of renal osteodystrophy were found in 23 and there were periarticular calcifications in 5. Only one patient had apatite associated knee arthritis and none had gout or calcium pyrophosphate deposition disease. Twenty patients had arthralgias, 3 polyarthritis, and 4 knee effusions all of which were incompletely explained. Correlations of arthralgias with radiographic findings was poor. Muscle cramps were seen in 24 patients, multiple fractures in one, symmetrical distal neuropathy in 18, and carpal tunnel syndrome in 9.

Adolescent↗
PubMed1984

Clinical and pathologic studies of synovitis in polymyalgia rheumatica.

Clinically detectable joint swelling was found in 10 of 13 fully evaluated patients considered to have polymyalgia rheumatica. Five patients had some joint findings at disease onset. Knees were most commonly affected. Sternoclavicular involvement was seen in 3 patients. Joint effusions in 8 patients had 300-5,700 leukocytes/mm3 with a mean of 2,900. Six synovial biopsy specimens studied by light microscopy revealed mild to moderate synovial proliferation and chronic inflammation that was generally less severe than in typical rheumatoid arthritis. Electron microscopy identified microvascular changes and large amounts of vesicular and granular debris in lining cells. In 1 patient, a "fingerprint" pattern in the granular material was suggestive of the findings in some immune complexes. This still unexplained synovitis may, as previously suggested, be important in the pathogenesis of the polymyalgia rheumatica syndrome.

Adult↗
PubMed1984

T cell antigens and MHC determinants on rabbit granulocytes.

A cell preparation, consisting of 90% granulocytes (polymorphonuclear leukocytes), can be obtained from the rabbit peritoneal cavity. These cells have some membrane antigens, similar to those characteristic of thymus cells (T1, T2), but they do not have the thymus antigen, RTLA. Unlike thymus cells, many polymorphonuclear leukocytes have Ia antigen, in their membranes. Heterogeneity of the cell population is indicated by differences in the number of cells affected by complement-mediated cytotoxic cell-kill with monoclonal antibodies, directed against T1 and T2 and with polyclonal antibodies directed against Ia.

Animals↗
PubMed1982

A comparison of regulatory cells from rabbit spleen and appendix.

Both spleen and appendix of the rabbit contain two types of accessory cells that regulate the response of T-cells to concanavalin A. These accessory cells are found among non-T, non-B adherent cells and among B-cells. There is, so far, no evidence for a sequential interaction of these two cell types. In addition, there is an inhibitory adherent cell type in the appendix that interferes with the B-cell-regulated proliferative T-cell response.

Animals↗
PubMed1982

Rabbit spleen B lymphocytes as helper cells in lymphocyte activation by concanavalin A and phytohaemagglutinin.

Using rosetting methods, we have purified rabbit B cells and studied their interactions with T cells purified by passage over an anti-immunoglobulin-coated Degalan beads column. B cells enhance the response of T cells to concanavalin A (Con A) and phytohaemagglutinin. In regulation of the response to Con A, an adherent cell is a third participating cell. B-cell preparation contain a minority of cells that can respond to T mitogens with the help of non-proliferating T cells, but the proportion of these responding cells is small, and the involvement of the T-cell impurity cannot be excluded.

Animals↗
PubMed1981

Relative expression of light-chain allotypic specificities on the surface of rabbit lymphocytes as a function of age.

Lymphoid cells of heterozygous Ab4/Ab9 rabbits of various ages were stained with fluorescent anti-allotype antibodies. In foetal and newborn rabbits, the percentage of Ab-positive cells in low; it increases with age, reaching the adult value when the animals are 100 days old. The rate of increase in the percentage of Ab4-positive cells is higher than in that of Ab9-positive cells. Thus, the Ab4/Ab9 ratio, which is initially 1, increases with age and reaches 2.2. in spleen and 4 in appendix of young adult animals. We conclude that the change in Ab4/Ab9 ratio is due to differential clonal expansion which we attribute to charge-related differences in the ability of Ab4 and Ab9 receptor-bearing cells to capture antigen when environmental antigens are encountered in postnatal life.

Aging↗
PubMed1980

The effect of temperature-dependent autorosettes on B/T cell ratios of purified rabbit peripheral blood lymphocytes.

Contradictory reports as to B/T cell ratios in the peripheral blood lymphocytes (PBL) of rabbits led to an investigation of current purification methods. PBL prepared by sedimentation at 37 degrees C in gelatin solution showed the same B/T ratios as did whole blood. PBL prepared by the Ficoll-Hypaque method at 4 degrees C or at room temperature were enriched in B cells compared to the whole blood. This enrichment depended on the presence of autologous erythrocytes during centrifugation and it was not demonstrable when centrifugation was carried out at 37 degrees C. Resuspended red cell pellets contained more than 3 times as many rosette-forming cells if the pellets were obtained by centrifugation of blood on Ficoll at 4 degrees C rather than 37 degrees C. We, therefore, conclude that aggregation of T cells with autologous erythrocytes is responsible for the depletion of B cells in the PBL prepared by the Ficoll-Hypaque method at 4 degrees C or at room temperature.

Animals↗
PubMed1980

Isolation and characterization of a mouse-rabbit hybridoma.

Immunoglobulin was obtained from a hybridoma cell line, which was a reclone of a hybrid between a rabbit cell and mouse myeloma cell (X63-Ag8). The immunoglobulin, isolated from the cell culture medium was found to be homogeneous by isoelectrofocusing and immunoelectrophoresis and consisted of mouse heavy and rabbit light chains, linked by disulphide bonds. All immunoglobulin molecules carried both mouse and rabbit determinants; mouse determinants were associated only with the heavy chains while rabbit determinants were only associated with the light chains. The rabbit light chains were of Ab4 allotypical specificity, but possess only some of the Ab4 determinants normally present in Ab4/Ab4 animals. It was suggested that the restriction in allotypical specificity may be a general property of light chain Ab allotypes; the normal serum immunoglobulins may be heterogeneous with respect to the allotypic determinants and any one molecule may possess only a proportion of determinants detected by a conventional anti-allotype antiserum.

Animals↗
PubMed1979

Purification of rabbit B spleen cells by removal of adherent and of T cells.

B lymphocytes from the rabbit spleen were freed of T cells by removal of cells which formed rosettes with papain-treated rabbit erythrocytes. Additional purification could be achieved if fractionation by rosette removal was preceded by removal with a magnet of cells which adhered to or ingested poly L-lysine coated iron core particles. Cell yield and purification were assessed by complement mediated cytotoxic kill of B and T cells with antibody directed against RABELA and RTLA, respectively. Other criteria depended on determination of the number of Fc receptor bearing cells and of thymidine uptake by cells which were stimulated with concanavalin A, PHA or with antibody directed against the allotypic specificity of receptor Ig light chains. Purified preparations of B cells were obtained in a yield of about 20% of the B cells in the original spleen and contained less than 10% of cells which were not B cells. This method allows purification which does not interfere with the membrane of the isolated cells.

Animals↗
PubMed1979

Regulatory influences on the response of rabbit T cells to concanavalin A and phytohaemagglutinin.

The proliferative response, induced in rabbit spleen cells by concanavalin A (Con A) and phytohaemagglutinin (PHA), is abolished when T cells are killed with antibody against rabbit thymus lymphocyte antigen (RTLA) in the presence of complement. The response was examined with purified spleen T cells, to which various helper cell fractions were added; it could be shown that B cells help the responding T cells. The helper effect in the response to PHA is abolished and the response to Con A is reduced by any manoeuvre which destroys or removes B cells. Help by B cells is given when helper cells have lost proliferative capacity as a consequence of mitomycin-C treatment. Spleen cells adhering to the walls of culture tubes help suspended T spleen cells in their response to Con A. This help could be abolished by complement mediated cell kill with antibody to rabbit bursal equivalent lymphocyte antigen (RABELA). On the other hand, the helper effect in Con A response was increased when T cells were removed. Thus the response of T cells to Con A is regulated by helper B cells and suppressor T cells.

Animals↗
PubMed1979

Immunoglobulin synthesis by thymus B cells.

Rabbit lymphoid cells transferred to newborn recipients synthesized donor-type immunoglobulin. Elimination of donor T cells did not affect this synthesis of donor immunoglobulin, while elimination of B cells abolished or significantly decreased the synthesis. The synthetic capacity of B cells from thymus was thirty-four times greater than the synthetic capacities of B cells from spleen, fifty-five times greater than that of mesenteric lymph nodes and 180 times greater than that of appendix cells. Synthetic activity of spleen cells ceased before the tenth day after transfer, while thymus cells might continue to synthesize immunoglobulin for a longer time. This was shown by comparing half-lives of donor immunoglobulin in the recipients' sera. Increasing the number of injected spleen cells (from 2 x 10(6) to 120 x 10(6)), resulted in a corresponding increase in donor Ig synthesis. With thymus cells, donor immunoglobulin increased with cell numbers up to 2 x 10(7) cells, above this dose there was no further donor immunoglobulin increase in the recipients' serum.

Animals↗
PubMed1979

Rabbit B spleen lymphocytes and T helper cells. I. Responsiveness to mitogens of B cell subpopulations of different sedimentation velocities and subpopulations bearing or lacking Fcgamma receptors.

The response to anti-allotype (anti-Ab4), Nocardia Water Soluble Mitogen (NWSM), pneumococcal polysaccharide type III (SSS III), and human Fc fragments of various purified and unfractionated rabbit spleen cell populations was determined in terms of 3H-thymidine up-take. B cells were isolated either from untreated suspensions of spleen cells or from suspensions from which adherent and phagocytic cells were removed. The purification factor was greater than the enhancement of 3H-thymidine uptake by anti-Ab4, NWSM, and SSS III as compared with the response of unfractionated spleen cells. It thus appears that a helper cell was involved: the mitogen response of purified B cells was enhanced by the addition of T cells. B subpopulations were separated by sedimentation or by rosetting, which allowed us to separate Fcgamma receptor-bearing cells from cells that did not possess this receptor. There were differences between cells responding to B mitogens not only in sedimentation velocity but also in the absolute number of cells. B cells bearing the Fcgamma receptor were less responsive to anti-Ab4 and more responsive to SSS III, NWSM, and human Fc than were B cells lacking the Fcgamma receptor.

Animals↗