To the Editor: Iervasi et al1 report a strong correlation between low free biologically active triiodothyronine (fT3), a thyroid hormone, and all-cause and cardiovascular mortality in 573 consecutive patients with heart disease. The observations in this study are stimulating and may be of major clinical interest. However, the following points deserve to be clarified for better appreciating the ...

A 63-year-old male presented with productive cough, fever, palpitation, shortness of breath, and mental confusion. Fulminant hepatic failure occurred with high aminotransferase and severe jaundice. Thyroid function tests showed thyroid-stimulating hormone level of 0.7 microU/mL (normal range, < 6.2 microU/mL), with normal serum thyroxine and triiodothyronine levels. He died on post-admission da...

High-affinity, limited-capacity nuclear binding activities, putative receptors for triiodothyronine, were detected after incubation of hormone with intact rat pituitary GH1 cells in culture, isolated GH1 cell nuclei, or rat liver nuclei. The total number of triiodothyronine binding sites per nucleus was similar in each case (approximately 8,000). The estimated equilibrium dissociation constants...

Selenium, as selenocysteine, is an integral component of two important enzymes — glutathione peroxidase and iodothyronine deiodinase — that are present in many tissues, including the thyroid gland. Glutathione peroxidase catalyzes the breakdown of hydrogen peroxide, thereby protecting against oxidative damage. Iodothyronine deiodinase catalyzes the deiodination of thyroxine to triiodothyronine,...

We measured concentrations of thyroxine, triiodothyronine, reverse triiodothyronine, thyroxine-binding globulin, and thyrotropin in pooled samples of cord sera from normal newborns. Sera collected in winter contain significantly (p less than 0.05) higher concentrations of the first tour--14.9, 13.4, 9k9, and 7.5%, respectively--than do sera collected in summer; thyrotropin concentrations are si...

Introduction: Determination of thyrotropin, total and free thyroxine and triiodothyronine are widely used as diagnostic methods for thyroid function evaluation. There have been numerous reports of interferences in thyroid hormone immunoassays. Herein, a prominent positive interference is reported for a radioimmunoassay kit of total triiodothyronine. Materials and Methods: In this study, a total...

We determined appropriate temperatures for sample storage and the resulting stability of 14 analytes commonly radioimmunoassayed in the clinical laboratory. Serum specimens to be tested for concentrations of cholylglycine, cortisol, digoxin, ferritin, follitropin, immunoglobulin E, lutropin, prolactin, thyroxin (also blood-spot thyroxin), triiodothyronine, and triiodothyronine uptake could be s...

We assessed the use of a dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA) system to measure thyrotropin (thyroid-stimulating hormone, TSH) in routine clinical practice. The assay is simple and precise, with intrabatch CV of less than 10% down to 0.1 milli-int. unit/L. When compared with free thyroxin, total thyroxin, and triiodothyronine measurements in 142 patients, the present assa...