BACKGROUND Owing to its large molecular size, polyethylene glycol (PEG)-precipitable thyrotropin (TSH) can accumulate in the circulation, elevating TSH levels. PEG-precipitable TSH can be used to detect macro-TSH (mTSH) in serum. Our aim was to evaluate the prevalence of mTSH in patients who had undergone thyroidectomy for thyroid cancer. METHODS Seventy-three thyroid cancer patients and 24 c...

We assessed the laboratory performance and clinical utility of a new commercial third-generation assay of thyroid-stimulating hormone (TSH), Amerlite TSH-30. The interassay CV was 6% at TSH concentrations of approximately 0.08 mIU/L, and the analytical and functional detection limits of the assay were 0.005 and 0.0125 mIU/L, respectively. Although the assay recovered approximately 96% of TSH In...

Normalization of basal thyrotrophin (TSH) level is used as the endpoint in L-thyroxine (L-T4) therapy of primary hypothyroidism. However, several reports have questioned the reliability of this index because of seasonal variation of TSH. Therefore, we studied 85 consecutive patients with primary hypothyroidism over a period of 3.5 y. In these patients, TSH response (delta TSH) to intravenous th...

Thyroid-stimulating hormone (TSH) action in adipose tissue remains largely unknown. Our previous work indicates that human preadipocytes express functional TSH receptor (TSHR) protein, demonstrated by TSH activation of p70 S6 kinase (p70 S6K). We have now studied murine 3T3-L1 preadipocytes to further characterize TSH signaling and cellular action. Western blot analysis of 3T3-L1 preadipocyte l...

CONTEXT Measurements from all age groups defined the upper limit of the TSH reference range in National Health and Nutrition Examination Survey III. The TSH median, 97.5 centile and prevalence of subclinical hypothyroidism (SCH), normal serum T(4) and TSH greater than 4.5 mIU/liter, increased progressively with age. Age-adjusted reference ranges would include many people with TSH greater than 4...

Objetivos. Describir el nivel de hormona tiroestimulante (TSH) y tiroxina plasmática libre (T4L) en escolares con sobrepeso obesidad; además, determinar asociación entre TSH factores riesgo cardiovascular. Métodos. Participaron del estudio 96 mujeres, 7 a 17 años, eutiroideas. Se definió IMC 85 < 95p obesidad ≥ 95p. determinó glucosa, triglicéridos, colesterol total, alta baja densidad, T4L....

Cultured dog thyroid cells were used to investigate the mechanism by which previous exposure to thyrotropin (TSH) induces refractoriness to further TSH stimulation of cellular adenosine 3'-5'-monophosphate (cAMP). Refractoriness of the cAMP response to TSH could not be overcome by exposure of the cells to supramaximal stimulatory concentrations of TSH. Although an unknown factor present in huma...

To the Editor: Comparisons of the Vitros ECi thyroid-stimulating hormone (TSH) method with the AxSym (1 ), Immulite (1, 2), Elecsys (2 ), and ADVIA Centaur (2 ) have shown an unexplained progressive negative bias ,0.2 mIU/L, a phenomenon that we have also observed (Fig. 1A). To investigate the bias, we diluted the TSH International Reference Preparation 80/558 (predominately pituitary TSH) and ...