Studies of the possibility that thyroxine (T4) is converted to 3.5,3'-triiodo-L-thyronine (T3) in the extrathyroidal tissues in man have been conducted in 13 patients, all but two of whom were athyreotic or hypothyroid, and all of whom were receiving at least physiological replacement doses of synthetic sodium-L-thyroxine.T3 was found in the sera of all patients, in concentrations ranging betwe...

Intrauterine growth restriction (IUGR) is associated with accelerated growth and increased adiposity in early life due to unknown mechanisms, which could include increased thyroid hormone (TH) action. We hypothesized that placental restriction (PR) of fetal growth would increase circulating TH concentrations and alter their response to fasting, and that these would relate to growth and body com...

Neonatal changes in plasma total and free iodothyronine levels were monitored in 18 Limousin X Romanov suckling lambs (experiment 1) and 24 Limousin X Romanov animals bottle-fed in standardized conditions (experiment 2). In the two experiments, plasma free T3 levels were closely related to total T3 levels, whereas some differences could be observed between total and free plasma T4 levels. The n...

BACKGROUND It is well known that certain non-thyroidal critical illness may lead to euthyroid sick syndrome(ESS). There are little reports about the change of thyroid hormone in the children's central nervous system (CNS) infections. RESULTS The results of serum TT3, TT4 and TSH in these children were compared with those in 20 cases of healthy adults and 20 cases of adults with primary hypoth...

1. Iodothyronine 5'-deiodinase, which is mainly responsible for peripheral triiodothyronine (T3) production, has recently been demonstrated to be a selenium-containing enzyme. In the elderly, reduced peripheral conversion of thyroxine (T4) to T3 and overt hypothyroidism are frequently observed. 2. We measured serum selenium and erythrocyte glutathione peroxidase (as indices of selenium status),...

Mutations of the monocarboxylate transporter 8 gene (MCT8, SLC16A2) cause the Allan-Herndon-Dudley syndrome, an X-linked syndrome of severe intellectual deficit and neurological impairment. Mct8 transports thyroid hormones (T4 and T3), and the Allan-Herndon-Dudley syndrome is likely caused by lack of T3 transport to neurons during critical periods of fetal brain development. To evaluate the rol...

OBJECTIVE To characterize thyroid hormone levels at the time of diagnosis in the nosological types of thyrotoxicosis diagnosed in the population and to analyze determinants for serum thyroxine (T4) and tri-iodothyronine (T3). DESIGN Population-based study of thyrotoxicosis at disease onset. METHODS In the period 1997-2000, we prospectively identified all patients diagnosed with incident pri...

Thyroid function was assessed at the time of initial diagnosis in 204 patients with lung cancer and compared with that of age and sex-matched patients with non-malignant lung disease. Abnormalities in thyroid function were found in 67 patients (33%). The most prevalent abnormality was a low T3 concentration; this was not associated with other clinical or biochemical evidence of hypothyroidism, ...

Endoscopic thoracic sympathectomy is routinely used to treat severe hyperhidrosis. It is usually performed at the T2-T3 level of the nerve, but may produce less severe compensatory hidrosis if performed at a lower level. This study evaluates the outcome of 1,274 patients who underwent endoscopic thoracic sympathectomy for plamar, plantar, axillary or facial hyperhidrosis/blushing. Half of the p...

The uptake and efflux of reverse triiodothyronine (rT3) in JAr cells were investigated. Uptake of 125I-rT3 was time dependent and reversible with a saturable component of around 70 per cent of total uptake after 30 min of incubation. Efflux was not saturable. Kinetic analysis of the initial specific uptake rates revealed an uptake process with a Michaelis constant of 3.04+/-0.53 microM (mean+/-...