of the thyroid gland, a reasonable choice of therapy would be to try to correct the alteration in the immune system that initiated the disease. However, this therapeutic approach has yet to be perfected. Therefore, the alternative course of treatment of Graves’ disease is to control the excessive production and release of the thyroid hormones, thyroxine (T4) and triiodothyronine (T3), from the ...

The response to an intravenous dose of 200 microng of thyrotrophin releasing hormone (TRH) has been studied by estimating, by radioimmunoassay, baseline levels followed by further estimations of thyroid stimulating hormone (TSH) 20 minutes after the injection and triiodothyronine (T3) three hours after the injection in 112 patients referred for routine thyroid assessment. Comparison of diagnost...

Laboratories participate in collaborative quality-assurance programs to maintain and improve the quality of their diagnostic assays, but little attention has been paid to diagnostic quality in these programs. We used a national quality-assurance program to assess the quality of laboratory reference intervals as exemplified by triiodothyronine, thyroxin, and thyrotropin immunoassays. The limits ...

A T4 suppression test involving 24-h thyroidal 131I uptake was carried out on patients with Graves' disease during therapy with an antithyroid drug. Thirty-three patients received propylthiouracil (PTU) for at least 1 year. Each patient was given 75 micrograms L-T3 daily for 8 days in conjunction with PTU (50 mg/day) at the time of the experiment and then the 24-h thyroidal 131I uptake (post T3...

We measured serum thyroxine (free and total), triiodothyronine (free and total), thyroxine-binding globulin, and triiodothyronine uptake by talc in 97 normal men and 50 pregnant women. Mean serum thyroxine and triiodothyronine concentrations were higher in the pregnant subjects (104 vs. 78 mug/liter and 1.69 vs. 1.30 mug/liter) because of a higher mean thyroxine-binding globulin concentration (...

Previous studies in vitro have revealed that L-754,394, an HIV protease inhibitor, is a potent suicide inhibitor of cytochrome P-450 enzymes. The present report examines the effect of chronic treatment of L-754,394 on hepatic cytochrome P-450s in adult male rats. L-754,394 was administered orally once a day for 7 days and resulted in significant changes in marker activities. An unusual paraboli...

Concentrations of free thyroxin (T4) and free triiodothyronine (T3) were measured in sera from pregnant women, in subjects with congenitally increased or decreased thyroxin-binding globulin (TBG), and in euthyroid controls. Measured free hormone concentrations were compared with calculated values for free hormone derived from concentrations of total T4, total T3, and binding proteins. Measured ...

Studies in hypothyroid rats show that, when infused with a combination of thyroxine (T4) plus triiodothyronine (T3) to normalize thyrotropin (TSH), euthyroidism in all organs is only ensured when T(4) and T(3) are administered in a ratio as normally secreted by the rat thyroid. As substitution with T(4)-only results in an abnormal serum T(4)/T(3) ratio, it is also possible that in humans, euthy...

Before the middle of XX century treatment of hypothyroidism implied prescription to the patients animals’ thyroid extracts, containing both, thyroxine and triiodothyronine [Oppenheimer JH, 1995]. Those drugs, in which it was almost impossible to measure the dose of thyroid hormones precisely, could not adequately provide euthyroidism. Moreover, it was rather difficult to prescribe proper doses....

Serum triiodothyronine (T-3) concentrations have been estimated by radioimmunoassay using unextracted serum. The serum T-3 concentrations have been shown to be similar in two separate European populations (0.76-1.67 ng/ml). Raised T-3 values have been observed in all subjects with hyperthyroidism. Low values are seen in hypothyroidism although there is some overlap with the normal range. There ...