T3-release from autonomously functioning thyroid nodules in vitro.

Toxic thyroid nodules have been shown to be of clonal origin. In a portion of them, point mutations affecting either the gene of the TSH receptor (TSHr) or the alpha-subunit of stimulating G-protein, consecutively leading to enhanced cAMP levels, which may enhance growth or functional activity of the thyrocyte or both, were recently found. To complement these studies, we evaluated hormone response (i.

Second generation assay for thyrotropin receptor antibodies has superior diagnostic sensitivity for Graves' disease.

Detection of autoantibodies to the TSH receptor (TSH-R) in Graves' disease has found widespread use in clinical routine and is performed mostly by commercial RRAs measuring TSH binding inhibitory activity. We report in this study on a second generation TSH binding inhibitory assay using the human recombinant TSH-R with two major improvements: 1) superior diagnostic sensitivity for Graves' disease, and 2) for the first time, nonradioactive and radioactive coated tube (CT) technology. Full-length human recombinant TSH-R was expressed in the K562 leukemia cell line and grown in suspension at a high density.

Pre-evaluation and system optimization of the Elecsys thyroid electrochemiluminescence immunoassays.

We present the results of a pre-evaluation of the thyroid function test free thyroxine, free triiodothyronine and third generation TSH using the Elecsys electrochemiluminescence immunoassay system. A collaborative field study between the development center of the manufacturer and a clinical chemistry laboratory addressed the reliability and comparability of the new Elecsys assays to established methods under clinical laboratory conditions using samples from routine in vitro thyroid testing. Preliminary (reference) formulations of the reagents and several electrochemiluminescent pilot models were used for assay measurements, either in the company's research center or in the clinical setting.

Regulation of intercellular adhesion molecule-1 expression in human thyroid cells in vitro and human thyroid tissue transplanted to the nude mouse in vivo: role of Graves' immunoglobulins and human thyrotropin receptor.

To further explore a potential role for the human TSH receptor (hTSHR) in the propagation of thyroid autoimmune disease, we examined immunomodulatory effects in response to its stimulation by Graves' Igs both in human thyroid tissue transplanted to the nude mouse and in primary cultures of human thyrocytes. We injected nude mice bearing transplants derived from normal human thyroid with protein A-Sepharose-purified Graves' IgGs (0.05-1 mg) on 2 days and assessed, in addition to functional stimulation, the expression of intercellular adhesion molecule-1 (ICAM-1) by transplant thyrocytes.

Enhanced functional activity in thyroid adenomas in vitro.

The majority of thyroid adenomas have been shown to be of clonal origin. In a portion of them, somatic or germline point mutations leading to altered TSH receptor or Gs alpha-proteins have been found. The constitutive activation of these proteins consecutively stimulate cAMP-levels.