ABSTRACT
Anti-Gal is a human polyclonal antibody that constitutes approximately 1% of the circulating immunoglobulin G (IgG), interacts specifically with the mammalian carbohydrate alpha-galactosyl epitope. Furthermore, it was found to mimic in vitro thyrotropin (TSH) effects regarding stimulation for cyclic adenosine monophosphate (cAMP) synthesis, 125I uptake, and cellular proliferation on cultured porcine thyrocytes and on Graves' disease thyrocytes, but not on normal human thyrocytes. As immune activation in sporadic and endemic goiters might play a secondary role in regulating thyrocyte proliferation and function, we evaluated anti-Gal titers in endemic goiter. Serum was obtained from 109 Chagas'-negative patients living in an endemic goiter area of Brazil (Grao Mogol, MG) and 160 controls. The patients were divided into 3 groups, according to their goiter size (World Health Organization [WHO] classification): grade 0 (group 1, n = 24), grade I-II (group 2, n = 41), and grade III-IV (group 3, n = 44). Anti-Gal was assessed by a radioimmunological procedure (results expressed as the percentage of bound radioactivity/total activity [%B/T]). The antibody titer was significantly more elevated in group 1 (mean +/- SEM: 9.27%+/-0.80%), in group 2 (mean +/- SEM: 16.17%+/-0.97%), and in group 3 (20.97%+/-1.30%) than in normal controls (6.46%+/-0.33%). Analysis of the male and female data separately for anti-Gal titer did not substantially alter these results. We concluded that the anti-Gal titer is higher in patients with endemic goiter and presented a possible relationship with the size of goiter. Whether these antibodies contribute to the pathogenesis of the disease needs further clarification.
Subject(s)
Autoantibodies/blood , Galactose/immunology , Goiter, Endemic/blood , Goiter, Endemic/immunology , Immunoglobulins, Thyroid-Stimulating/blood , Adult , Aged , Aged, 80 and over , Female , Goiter, Endemic/classification , Humans , Male , Middle Aged , Radioimmunoassay , Reference Values , Thyroglobulin/blood , Thyrotropin/blood , Thyroxine/bloodABSTRACT
Two radioimmunological techniques for the measurement of anti-alpha-galactosyl (anti-Gal) antibodies were developed and we demonstrated that this antibody is present in the serum of most untreated patients with Graves' disease, thyroid-associated ophthalmopathy (TAO) and autoimmune thyroiditis. Thyrotropin-binding inhibiting immunoglobulins (TBII) and Thyroid Stimulating Antibodies (TSAb) are frequently found in serum of patients with Graves' disease but not with autoimmune thyroiditis. Although TBII and anti-Gal were found sometimes simultaneously in the same serum samples, we demonstrated that anti-Gal could be present in the absence of TBII and reciprocally.
Subject(s)
Autoantibodies/blood , Eye Diseases/immunology , Graves Disease/immunology , Radioimmunoassay/methods , Thyroiditis, Autoimmune/immunology , Trisaccharides/immunology , Animals , Autoantibodies/metabolism , Eye Diseases/etiology , Graves Disease/complications , Humans , Immunoglobulins, Thyroid-Stimulating/blood , Mice , Radioimmunoassay/statistics & numerical data , Receptors, Thyrotropin/metabolism , Sensitivity and SpecificityABSTRACT
An immunoradiometric assay (IRMA) for the determination of human Sex Hormone Binding Globulin (SHBG) in serum is described. This IRMA uses three mouse monoclonal antibodies. Two monoclonals anti-human SHBG are coated on tubes and used as capture antibodies. The third monoclonal labeled with 125I completes the system, allowing the formation of the "sandwich". The detection limit of the assay is 2.5 femtomol SHBG per tube (250 pg/tube). Using this test for the measurement of SHBG and radioimmunoassays for the determination of total Testosterone and Estradiol, we calculated the Free Androgen Index (FAI) and the Free Testosterone. The results obtained were compared with the values of Free Testosterone measured by equilibrium dialysis. There is a close correlation between both calculated parameters and the levels of Free Testosterone, validating this SHBG assay.
Subject(s)
Antibodies, Monoclonal , Immunoradiometric Assay/methods , Sex Hormone-Binding Globulin/analysis , Estradiol/blood , Evaluation Studies as Topic , Humans , Immunoradiometric Assay/standards , Immunoradiometric Assay/statistics & numerical data , Reference Standards , Serum Albumin/analysis , Sex Hormone-Binding Globulin/immunology , Sex Hormone-Binding Globulin/standards , Testosterone/bloodABSTRACT
The effect of barium on isolated acini was tested. Barium in the 0.1-10 mM concentration range non-competitively inhibited the efflux of 86Rb+ stimulated by carbamylcholine or substance P. This inhibition was independent of the presence of calcium in the extracellular medium. In the same preparation, barium did not affect the efflux of 45Ca2+ but, at a 10 mM concentration, it increased amylase release by 70%. Removal of extracellular calcium decreased basal amylase release and the response to carbamylcholine. Adding back calcium or barium to the incubation medium increased basal and carbamylcholine-stimulated amylase secretion, but calcium was more effective than barium. These results suggest that barium has two opposite effects on calcium-regulated processes in rat parotid gland: (1) it is an inhibitor of calcium-activated potassium channels; (2) it is a partial agonist of calcium-activated amylase secretion.
