In vivo, immunocompetent T lymphocytes are only detected late in ontogeny, among mature thymocytes expressing either T4 (L3T4 in mouse) or T8 (Lyt-2) surface glycoproteins. We have previously shown, however, that there are functional precursors among T3+4-6-8- human thymocytes in vivo. Here we report on the in vitro differentiation of prothymocytes into T3+4-6-8- and mature T cells. T11+3-4-6-8...

A 40-year-old hypothyroid female who had been treated with synthetic thyroxine was admitted to our hospital in October 1988 due to abnormal liver function tests. She had low serum free triiodothyronine (T3; 2.3 pg/ml) and high serum thyrotropin (TSH; 20.8 microU/ml) concentrations. On the other hand, the serum free thyroxine (FT4) level was inappropriately high, being 2.46 ng/dl. Immune precipi...

1. The effect of yohimbine (Y) on blood levels of thyroxine (T4), triiodothyronine (T3), and cortisol was investigated in 5 mature male white-tailed deer immobilized with xylazine hydrochloride (X). 2. T4 levels were erratic in X-treated deer, but stabilized in the X- and Y-treated deer. 3. T3 remained unchanged in both groups. 4. Cortisol levels have increased in X-treated deer, but declined i...

Address correspondence and requests for reprints to: Leonidas H. Duntas, M.D., Endocrine Unit, Evgenidion Hospital, University of Athens, 20 Papadiamantopoulou Str., 11528 Athens, Greece, e-mail: [email protected] Received 16-03-05, Accepted 30-03-05 mainly owing to lesser affinity of the serum binding proteins for T3. At times T3 has been added at various dosages or as a fixed preparation, cont...

Thyroid hormones regulate adipogenic differentiation, lipogenic and lipolytic metabolism, and mitochondrial activity in adipose tissue. Triiodothyronine (T3) levels in tissues are regulated by the deiodinase enzymes. The objective was to study the activity and messenger RNA (mRNA) expression of the 5' outer-ring deiodinases (type 1 [D1] and type 2 [D2] deiodinase) and thyroid hormone concentrat...

BACKGROUND A relatively unexplored area for biomarker identification is alternative splice variants. We undertook this study to evaluate the usefulness of mRNA isoforms encoded by the KLK8 (kallikrein-related peptidase 8) gene as prognostic markers for lung cancer. METHODS Real-time reverse-transcription PCR was used to analyze the mRNAs encoded by KLK8 (particularly 2 mRNA splice variants, K...

The present comments are restricted to the role of maternal thyroid hormone on early brain development, and are based mostly on information presently available for the human fetal brain. It emphasizes that maternal hypothyroxinemia - defined as thyroxine (T4) concentrations that are low for the stage of pregnancy - is potentially damaging for neurodevelopment of the fetus throughout pregnancy, ...

Thyroid hormones (THs) are key regulators of metabolism. The thyroid gland produces both thyroxine (T4) and triiodothyronine (T3). T4 is the main product and is converted in the periphery via deiodination to T3 which is the main biologically active TH. The production of THs is regulated by thyrotrophin (TSH) in response to TSH releasing hormone (TRH). This, in turn, is regulated by a negative f...

We compared the uptake, metabolism, and biological effects of tetraiodothyroacetic acid (Tetrac) and rT3 in anterior pituitary cells with those of T4 and T3. Cells were isolated from adult male Wistar rats and cultured for 3 days in medium with 10% fetal calf serum. Uptake was measured at 37 C in medium with 0.1% BSA for [125I]Tetrac (200,000 cpm; 240 pM) and [125I]T4 (100,000 cpm; 175 pM) or w...