Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0028754 (obesity)
 124,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The binding of chicken thyroglobulin-coated chicken red blood cells by splenic, thymic, and bursal lymphoid cells was analysed in Obese strain (OS) chickens with spontaneous autoimmune thyroiditis and normal white Leghorn controls aged 1 week to 2.5 yr. Chicken erythrocytes coated with pneumococcal polysaccharide SIIII served as controls. The specificity of thyroglobulin-rosette-forming cells was verified by inhibition experiments. OS chickens showed significantly higher counts of thyroglobulin-rosette-forming cells in the spleen and thymus as compared to normal controls while no such difference was found for SII-rosette-forming cells. The values obtained with bursal lymphoid cells were in the same range in both OS and normal white Leghorn birds. The appearance of thyroglobulin-rosette-forming cells and their peak values clearly preceded the maximum frequency and severity of thyroiditis and the peak of the thyroglobulin antibody curve. It is concluded that the presence of thyroglobulin rosette-forming cells is a prerequisite for the future development of spontaneous autoimmune thyroiditis in the OS. Inhibition studies with specific turkey anti-chicken bursa and thymus cell sera revealed the B cell nature of active thyroglobulin-rosette-forming cells and suggested that passive rosette-forming cells were of T cell origin.
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PMID:Thyroglobulin-binding lymphoid cells in obese strain (OS) chickens. 23 98

Homozygeous nu/nu mice do not develop experimental autoimmune thyroiditis and circulating thyroglobulin autoantibodies after two immunizations with murine thyroid extract and fortified complete Freund's adjuvant. However, heterozygeous nu/+ mice are perfectly apt for the induction of both thyroiditis and thyroglobulin autoantibodies. These results provide further evidence for the assumption that the development of experimentally induced autoimmune thyroiditis depends on the presence of T-cells as opposed to the spontaneously occurring autoimmune thyroiditis in Obese strain (OS) chickens which is mediated by B-effector cells. The present data further show that thyroglobulin is a T-dependent antigen in the mouse.
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PMID:No development of experimental autoimmune thyroiditis in nude mice. 30 59

Antigen-coated particles of cross-linked dextran may be used for affinity chromatography of antibodies and for the fractionation of lymphoid cells with appropriate surface receptors. Furthermore, such particles serve as convenient substrates for quantitative immunofluorescence tests. The fluoro-immuno-cyto-adherence (FICA) is a simple technique which combines affinity chromatography and immunofluorescence, provides durable antigen-coated substrates and allows the identification, enumeration and characterization of lymphoid cells capable of binding an antigen, covalently linked via a spacer onto the surface of dextran beads. In the present study chicken thyroglobulin (TG) or bovine serum albumin (BSA) were coupled onto fluorescein and rhodamin-labelled or unlabelled Sephadex G-25 beads by means of spacer molecules. The specificity and degree of antigen-coating were controlled by indirect immunoflourescence. For the study of antigen-binding cells the different antigen-coated beads were mixed with suspensions of peripheral blood lymphoid cells from Obese strain (OS) chickens with spontaneous hereditary autoimmune thyroiditis, or with cells from BSA-immunized or unimmunized normal White Leghron chickens. Specific adherence of OS lymphocytes to TG-coated beads and of lymphocytes from BSA-immunized chickens to BSA-beads was found. The test and control preparations are observed simultaneously under the fluorescence microscope where the distinction of beads coated with different antigens can be made on the basis of the color of their fluorescence. Results obtained with the FICA technique are in good agreement with those of conventional rosette tests.
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PMID:Fluoro-immuno-cytoadherence (FICA): A new method for the identification and enumeration of antigen-binding cells. 32 Jul 68

All major lymphoid organs from animals of the Obese strain (OS) of chickens which develop a spontaneous autoimmune thyroiditis with circulating thyroglobulin autoantibodies (Tg-AAb) were investigated for Tg-AAb producing cells using the immunofluorescence method (IF). No Tg-binding cells could be detected in spleen, bursa. Harderian glands, thymus, coecal tonsils or bone marrow. The infiltrated thyroid gland was shown to be the only site of Tg-AAb production detectable by IF.
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PMID:Immunofluorescence localization of thyroglobulin autoantibody producing cells in various organs of obese strain (OS) chickens. 34 76

The Obese strain (OS) of White Leghorn chickens develops a spontaneous autoimmune thyroiditis with circulating thyroglobulin-autoantibodies (Tg-AAb) similar to human Hashimoto thyroiditis. The paper describes attempts to localize the site of Tg-AAb production in various organs of these animals using the immunofluorescence method. Tg-AAb producing plasma cells and germinal centers could be detected in the infiltrated thyroid glands but not in spleen, bone marrow, coecal tonsils, thymus, bursa of Fabricius and Harderian glands.
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PMID:Immunofluorescent localization of thyroglobulin--autoantibody producing cells in various organs of obese strain (OS) chickens. 56 3

Thyroglobulin-binding lymphoid cells were identified in the spleen of Obese strain (DS) chickens by their capacity to form rosettes with thyroglobulin-coated chicken red blood cells. The nature of these cells was studied in inhibition experiments using turkey anti-chicken bursa or thymus cell sera and rabbit antisera specific for chicken Ig, gamma, mu, alpha, Fabgamma or Fcgamma. Spleen cells actively synthesizing surface receptors for thyroglobulin were identified as B cells and the receptors found to be complete IgM molecules. Normal T cells became thyroglobulin-rosette-forming cells via passive adsorption of thyroglobulin antibodies, a phenomenon which could be inhibited competitively by the addition of normal chicken serum to the incubation medium. Thyroglobulin antibodies passively adsorbed onto the surface of normal T cells also belong to the IgM class as verified both by inhibition experiments and studies employing IgM and IgG fractions of a high titered OS serum for the preincubation of the cell suspensions. Only preincubation with the IgM fraction of the anti-thyroglobulin antibodies resulted in the formation of significant numbers of passive rosette-forming cells.
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PMID:The nature of active and passive thyroglobulin binding lymphoid cells in Obese strain (OS) chickens. 82 40

F1-hybrids of Obese strain (OS) chickens, afflicted with spontaneous autoimmune thyroiditis (SAT), and normal, inbred CB chickens, do not develop severe thyroiditis. About 50% of these crosses show circulating autoantibodies to thyroglobulin (TgAAb), but the thyroid glands are only slightly infiltrated, suggesting that the target organ is not susceptible to autoimmune attack. In the present study we show that despite this mild infiltration TgAAb are only synthesized by lymphoid cells within the thyroid gland. Furthermore, we demonstrate that immunization with chicken thyroglobulin (Tg) in complete Freund's adjuvant causes severe experimental autoimmune thyroiditis (EAT) in F1(OSxCB) hybrids.
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PMID:Target organ susceptibility and autoantibody production in an animal model of spontaneous autoimmune thyroiditis. 139 97

Dietary iodine has been shown to be important in the induction of thyroiditis in susceptible chicken strains although the underlying mechanism remains unknown. Iodine may exert its effects through the formation of reactive oxidative radicals which would cause thyroidal injury and initiate infiltration. We have tested this hypothesis by examining the ability of butylated hydroxyanisole (BHA), ethoxyquin, and other antioxidants to prevent thyroiditis in Obese strain (OS) chickens, a strain that develops severe disease by 4 weeks of age. BHA, when administered from hatching until death at 5 weeks of age, reduced thyroidal infiltration and serum levels of antibodies binding thyroglobulin, T3, T4. Similar effects were observed with the antioxidant ethoxyquin. Weaker antioxidants such as vitamins C and E and beta-carotene had only slight or negligible effects on these parameters. BHA reduced thyroiditis in OS chicks killed at 3 and 5 weeks of age, but not at 8 weeks. When BHA treatment was initiated after the development of severe disease, it did not reduce thyroglobulin antibody levels. To determine the mechanism by which BHA reduces thyroiditis, studies were performed to assess the effect of BHA on thyroid function and on the immune responses to exogenous antigens. BHA had no effect on thyroid function in normal strain chickens since thyroidal radioiodine uptake and organification and serum T3 and T4 levels were unaffected. BHA did not alter immune responses to exogenous antigens such as sheep red blood cells or Brucella abortus in OS chickens. In summary, potent antioxidant drugs delayed the onset of thyroiditis when treatment was initiated before the onset of disease, suggesting that reactive oxygen intermediates are involved in the early stages of pathogenesis. However, the site of action remains unknown since they had no detectable effects on thyroid function or general immune responses.
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PMID:Antioxidants delay the onset of thyroiditis in obese strain chickens. 240 Dec 27

For the analysis of the genetic background of autoimmune thyroiditis we used the Obese strain (OS) chicken model which develops a SAT. Practically all animals from this strain show severe lymphoid infiltration of the thyroid gland and circulating autoantibodies against thyroglobulin (Tg-AAb) within a few weeks after hatching. Of the 3 MHC haplotypes (B5, B13, B15) present in the OS, B13 was mostly associated with severe thyroid infiltration. Haplotypes B5 and B15 were associated both with severe, as well as with mild infiltration. To clarify these controversial results published by different groups and to further assess the role of the MHC in the development of SAT, we selected by appropriate breeding sublines with high and low levels of Tg-AAb. With the help of serological methods and GvH assays we were not able to find additional differences in the MHC antigens of that line. Therefore, for further characterization of these haplotypes, RFLP analysis was applied in the present study. Southern blots were done with restriction enzyme digests of erythrocyte DNA hybridized with a chicken cDNA probe (code-p234) for MHC class II antigens. The Southern blots with BamH-I digests showed at least 5 bands, four of which were polymorphic. Four RFLP patterns emerged, two of which were observed within chickens with the B15 haplotype. The confirmation of this RFLP heterogeneity within serologically identical haplotypes requires additional analysis.
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PMID:Typing of MHC haplotypes in OS chicken by means of RFLP analysis. 257 97

The characteristics of thyroglobulin (Tg) autoantibodies in Obese strain (OS) chickens with thyroiditis have been defined and compared with those of polyclonal antibodies to chicken Tg produced by immunizing normal chickens and a rabbit, and with mouse monoclonal antibodies (MoAb) to chicken Tg. Chicken Tg autoantibodies (aAb), when tested against Tg from 24 species all showed specificity for chicken Tg which ranged from absolute to limited although in most instances cross-reactions with Tgs of other species were either absent or at a low level. Antibodies to chicken Tg produced by immunization showed a similar limited range of cross-reactions. Four of five chTg-MoAbs were specific for chicken Tg and the fifth was almost so. In competitive experiments, the polyclonal rabbit antibody could fully inhibit binding of all chicken Tg-aAb to chicken Tg but not vice versa. It was inferred that polyclonal rabbit Tg antiserum includes antibodies to all the epitopes seen by chicken Tg-aAb and many more besides. In similar experiments with four chicken Tg-MoAbs, the binding of one chicken Tg-aAb was unaffected, and three other patterns of inhibitions were defined. The binding to chicken Tg of a fifth chicken Tg-MoAb was enhanced rather than inhibited by chicken Tg-aAb. Some but not all chicken Tg-aAb preparations could differentiate between Tgs containing different amounts of thyroxine. We conclude that the autoantibodies to Tg in OS chickens are directed in the main against determinants unique to the species. Not all the species-specific determinants are involved in the autoimmune response but the number of epitopes involved is at least four. In these respects the immune response to Tg in OS chickens resembles that in autoimmune thyroid disease in humans. The conformation of chicken Tg may be affected by combination with antibody or by the content of thyroid hormone.
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PMID:Selective autoimmune response to the chicken-specific structures of thyroglobulin in Obese strain chickens. 276 75


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