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Biomedical subjects

C T Chou

Publications and source records attributed to C T Chou.

At least 55 records · Page 3Linked to original sources

Interferon production from peripheral blood, synovial fluid, and synovial tissue lymphocytes in patients with rheumatoid arthritis and ankylosing spondylitis.

A previous study demonstrated that interferon was present in the serum of 30% of the patients with systemic lupus erythematosus (SLE), which was significantly higher than the 4.5% found in normal controls. We also recently reported that interferon production was deficient from SLE mononuclear cells, which has been attributed to immunodeficiency of the lymphocytes. In this study, interferon measurement included lymphocytes obtained from peripheral blood (PB), synovial fluid (SF) and synovial tissue (ST) in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS). PB from normal subjects (NS) was used as a control. The results showed with PHA stimulation, that the interferon level in PBL (L = lymphocyte) in NS (70.0 +/- 67.5) was significantly higher when compared with PBL in RA (27.9 +/- 21.6). However, there was no difference between PBL in NS and AS. With ConA stimulation, the interferon level was significantly higher in the PBL of NS (130 +/- 59) and as compared with the PBL in RA (83.6 +/- 53.5). The SFL in RA (67.8 +/- 31.1) and the STL in RA (77.2 +/- 93.2) were also significantly different. It is concluded that interferon production was deficient not only in PBL in RA, but also in SF and STL in RA. The reduced interferon production from PB, SF and ST lymphocytes in RA patients may be due to previous release or immunodeficiency. Lymphocyte interferon production was normal in AS, which suggests that the lymphocyte abnormality between RA and AS may be different.

Adult↗

[The occurrence and clinical significance of antibodies to type II collagen in sera and synovial fluid of Chinese patients with rheumatoid arthritis].

Antibodies to type II collagen (Col II) in sera and synovial fluid (SF) were measured with an enzyme linked immunosorbent assay (ELISA) using a solid phase sandwich method. The subjects included: 42 patients with rheumatoid arthritis (RA); 31 cases of osteoarthritis (OA); 10 cases of gouty arthritis; 4 cases of ankylosing spondylitis (AS); 5 cases of systemic lupus erythematosus (SLE); and 44 normal controls. The antigens used to detect antibodies against Col II were in native and heat-treated denatured forms, both of which were purified from chicken sternal cartilage by limited enzyme digestion and differential precipitation with salt. The reactivity to native type II collagen was generally higher than the reaction to the denatured collagen. In sera, significant higher levels of Col II were detected in the different arthritis groups when compared with the normal control group, with the exception of AS. In SF, the Col II was significantly higher in RA than it was in OA (p less than 0.001), while no difference was present between gout and OA (p less than 0.05). When native Col II was simultaneously measured in sera and SF among arthritics, positive rates were both higher among RA (65% and 58%, respectively). Positive rates were only higher in sera among OA (59% in sera and 3% in SF) and were both lower among gouty arthritis. The above findings show that the measurement of Col II is more important in SF than in sera.

Arthritis, Rheumatoid↗

Fluorescence-activated cell sorter (FACS) analysis of rabbit cells.

Monoclonal antibodies RB1, RB2, RT1, RT2 and RB3 were prepared against rabbit lymphoid cells by immunization with various fractions of rabbit lymphoid cells. The antigens detected by the antibodies are found on B and T cells in different densities. High proportions of polymorphonuclear and bone marrow cells which do not carry the RABELA and RTLA antigens carry the antigens of the RB and RT series. A subpopulation of appendix sIg-negative, RTLA-negative cells has a relatively high concentration of RT2. In general, B and T cells of the appendix show relatively small differences in the membrane densities of RB and RT antigens.

Animals↗

Cross-reaction of a monoclonal antibody to human MHC class II molecules with rabbit B cells.

Monoclonal antibodies, 21w4 and 44H10, against human MHC class II determinants, were analysed for their reactivity with rabbit lymphoid cells. Both MAb bind to all human B lymphoblastoid lines, irrespective of their HLA-DR phenotype. HLA-DR antigens, purified by affinity to 21W4 IgG Sepharose, can be precipitated with 44H10 MAb, indicating that both antibodies react with the same molecules. Competitive inhibition studies with purified MAb IgG show that 44H10 and 21w4 recognize different epitopes of HLA-DR molecules. The 21w4 MAb, previously shown to cross-react with cells of pig, mouse and sheep, does not react with rabbit lymphoid cells. The 44H10 MAb binds to lymphoid cell suspensions prepared from rabbit appendix, spleen and mesenteric lymph nodes. Its reactivity correlates with that of RABELA, a polyclonal antibody specific for rabbit B cells. Mesenteric lymph node and spleen cell suspensions, depleted of sIg+ cells, are devoid of 44H10+ cells, while similarly-treated appendix B cells still contain a subset of B cells which are sIg-, RABELA+ and 44H10+. These studies thus report on the presence of MHC class II determinants on rabbit B cells, cross-reacting with human HLA-DR.

Animals↗

Immunoglobulin A nephropathy and ankylosing spondylitis. Report of two patients in Taiwan and review of the literature.

We describe 2 patients with immunoglobulin A (IgA) nephropathy in association with ankylosing spondylitis. Renal biopsy demonstrated mesangial proliferative glomerulonephritis with prominent IgA, C3c, and less intense properdin deposition in the glomeruli. Intraglomerular clumps of virus-like particles were also observed in the kidney sample from one patient (case 2), who had an abnormal liver function. Our findings support the hypothesis that here is a possible common pathogenesis responsible for the concurrence of both IgA nephropathy and ankylosing spondylitis.

Adolescent↗

[The interrelationships of hepatitis B e antigen antibody and HBsAg-circulating immune complexes in asymptomatic HBsAg carriers].

The prevalence of asymptomatic HBsAg carriers and positive rate of HBsAg immune complexes (HBsAg-CICs) were comparatively higher among Chinese. The former is considered to be related with hepatitis B e antigen and the latter is not clear yet. In order to investigate the relationship between HBsAg-CICs and e antigen antibody among asymptomatic carriers. 90 subjects of carriers was tested for HBsAg-CICs by PEG-trypsinisation method and for e antigen antibody by radio-immunoassay. HBsAg-CICs were positive in 66 subjects among 90 carriers. The concentration of HBsAg-CICs (ng/ml) was significantly higher among 32 subjects with positive HBeAg (333.87 +/- 265.39) than 27 subjects with positive anti-HBe (181.03 +/- 162.05), p less than 0.02. Furthermore, the positive rate of e antigen and e antibody was just contrary among carriers with positive and negative HBsAg-CICs. Among 24 subjects with negative HBsAg-CICs, the percentage of positive HBeAg was much lower than positive e antibody. A significant interrelationship was present between positive or negative HBsAg-CICs and e antigen, antibody, the statistically significant was proved by the Chi square test. The above results showed that the high prevalence of asymptomatic HBsAg carriers among Chinese may be related to e antigen.

Antigen-Antibody Complex↗

Computer software for specimen orientation adjustment using double-tilt or rotation holders.

Computer software for specimen orientation adjustment relative to the incident electron beam has been developed. The difficulties encountered when tilting severely strained, highly beam-sensitive, or small-grain-size specimens with known structures using either a double-tilt or a rotation holder in transmission electron microscopy (TEM) can be minimized. Combined with computer programs for obtaining the reduced bases from diffraction patterns, the software is also useful for unknown crystals. The algorithm is introduced and examples are given.

Crystallization↗

Lymphokine-activated killer (LAK) cells: I. Age-dependent decline of LAK cell-mediated cytotoxicity.

Experiments were designed to assess age-related changes in generation of lymphokine-activated killer (LAK) cells and to test whether these changes can be modified by diets differing in the proportion of polyunsaturated to saturated fatty acids (P/S). Ficoll-Hypaque-isolated spleen lymphocytes of rodent chow-fed, 6-85-week-old C57BL/6 (H-2b), 8-81-week-old C57BL/10 (H-2b) and 6-62-week-old SJL (H-2s) mice were cultured in IL-2-containing medium and examined in 51Cr cytotoxicity assay. Similarly, Ficoll-Hypaque-isolated spleen lymphocytes of 6-36-week-old SJL mice fed diets which differed in the ratio of polyunsaturated/saturated fatty acids were cultured in IL-2-containing medium and assayed for cytotoxicity. Age-related decline of LAK cell-mediated cytolysis was observed in mice of both H-2b and H-2s haplotype. The age-related decline of LAK cell-mediated cytolysis was the consequence of age-related decrease in the rate of LAK cell precursor maturation. SJL mice fed from birth with diets differing in P/S did not differ in LAK cell-mediated cytolysis.

Aging↗

[Specific circulating immune complexes in patients with hepatitis B].

Antigen specific hepatitis B surface antigen circulating immune complexes (HBsAg-CICs) were measured in 109 cases of hepatitis B with positive HBsAg (among them, 49 cases were acute and 60 cases were chronic hepatitis), 96 cases of asymptomatic hepatitis B surface antigen carriers, and 95 cases of normal blood donors. The mean concentration (ng/ml) of HBsAg-CICs was 303.50 +/- 357.70, 319.26 +/- 334.35 and 179.66 +/- 234.26 for the first three groups respectively; and was negative in normal groups. The concentration of HBsAg-CICs were significantly higher in acute and chronic group when compared with the asymptomatic carrier's group, (p less than 0.02 and p less than 0.01, respectively). Longitudinal series studies showed a close correlation between the levels or changes of HBsAg-CICs and the activity of the disease; patients with persistent HBsAg-CICs had a poor prognosis; and this were true not only in acute but also in chronic hepatitis patients. The mean concentration of HBsAg-CICs was higher in patients with positive hepatitis B e antigen (HBeAg) than in negative; but lower in patients with hepatitis B e anti-body (anti-HBe) positive than in negative. The higher prevalence of HBsAg-CICs in sera among asymptomatic HBsAg carriers in our study might be related to the prevalence of HBeAg among Chinese carriers. Further more, because HBsAg-CICs was related to the activity and prognosis of hepatitis B, it is worthwhile reconsidering whether so called "healthy" carriers were really healthy when their sera HBsAg-CICs tested positive.

Antigen-Antibody Complex↗

The rabbit immune system: cells regulating the proliferative response of purified T cells to concanavalin A and phytohaemagglutinin.

T cell specific, B cell specific and Ia specific polyclonal antisera, as well as monoclonal antibodies, were employed to characterize cells involved in regulation of T cells, proliferating upon stimulation with concanavalin A or phytohaemagglutinin. Evidence for Ia+ accessory cells was obtained and the constellation of membrane antigens was determined by cytotoxic cell kill with the above mentioned antibodies. Help given by Ia+ cells was not blocked by polyclonal antibody against Ia, in the absence of complement. There was indirect evidence that a fraction of helper/accessory cells were Ia-.

Animals↗

Characterization of rabbit cells by monoclonal and polyclonal antibodies.

Reagents for the identification of rabbit cell markers have been developed at a relatively slow rate. In this paper, rabbit cells are being characterized by polyclonal antibodies against a T-cell antigen (RTLA), a B-cell antigen (RABELA) and an analogue of murine Ia antigen. A number of monoclonal antibodies, specific for lymphocytes and/or bone marrow and/or polymorphonuclear leucocytes, have been used for the analysis of cells with identifiable membrane antigens. Populations that have cells with two of the above antigens in the membranes were identified. To these ends, complement-mediated cell kill by antisera alone and in mixtures was employed.

Animals↗