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 ...

SH is defined as a serum thyroid stimulating hormone (TSH) above the upper limit of the reference range, with a serum T4 and T3 thyroxine within the reference range. Other causes of a raised TSH such as a past history of thyroid disease and patients on T4 hormone treatment need to be excluded. Although patients with subclinical thyroid disease are usually asymptomatic, but nearly 30% have sympt...

We present here the first performance evaluation of a new direct method for free thyroxin (T4) in serum by radioimmunoassay, with use of coated tubes and a radiolabeled T4 analog (Diagnostic Products Corp.). The assay is precise and robust: within-run imprecision (CV), 3.1-6.6%; between-run imprecision, 4.0-7.9%; no demonstrable variation between technologists irrespective of experience with th...

We have investigated one-point recalibration of heterogeneous enzyme immunoassays involving nonlinear calibration curves. By using a factor determined from a single standard we updated calibration curves obtained earlier by means of multiple-point determination. The prerequisite for this method is a reproducible working procedure, i.e., as ensured by a fully mechanized system. In our investigat...

The aim of this study was to see how a mixture of cadmium (Cd) and decabrominated diphenyl ether (BDE209) affect thyroid function, namely thyroid-stimulating hormone (TSH), thyroxin (T4), free thyroxin (FT4), triiodothyronin (T3), and free triiodothyronin (FT3) in Wistar rats (eight per group) receiving either a single substance or their combination by gavage for 28 days. Three groups were rece...

We used various kits to measure free thyroxin (T4) in serum from a patient with the very rare syndrome of euthyroid hyperthyroxinemia secondary to increased thyroxin-binding prealbumin in serum. This patient's free T4 by equilibrium dialysis was 13 ng/L (normal 9-21), whereas the free-T4 index was 18.6 (normal 5.5-11.5). Using six different commercial methods, the last three listed being T4-ana...

Using a two-site immunoradiometric assay, we measured concentrations of thyrotropin (TSH) in serum of 134 clinically euthyroid subjects, 93 patients with nonthyroidal illness, and 80 patients who were being treated with various drugs. Abnormal concentrations of TSH, free thyroxin, and free triiodothyronine, respectively, were recorded in serum of three (3.2%), 19 (20.4%), and 37 (39.8%) of the ...