Volume 91, Number 6 www.aafp.org/afp American Family Physician 359 Primary hypothyroidism is defined as low levels of blood thyroid hormone due to destruction of the thyroid gland. This destruction is usually caused by autoimmunity or an intervention such as surgery, radioiodine, or radiation. • It can be classified as clinical (overt) when diagnosed by characteristic clinical features, raised ...

We develop a novel method for finding sufficient experimental conditions for discriminating and quantifying individual biomolecule production sources in distributed, inhomogeneous multisource systems in vivo, and we apply it experimentally to a complex, unsolved problem in endocrinology. The majority of hormonal triiodothyronine (T3) is produced from prohormone thyroxine (T4) in numerous nonthy...

Free triiodothyronine was assayed in serum of 1050 euthyroid children with the Amerlex-MAB method. We studied 50 samples for each year of age, from < 1 to 20, and no child had more than one sample taken. A gradient of values was observed, increasing by 31% from 5.04 pmol/L as the mean of 20-year-old patients to 6.59 pmol/L in the serum of children younger than 1 year. For practical reasons the ...

The indirect indices of free-thyroxin concentration (fT4) are of limited effectiveness in diagnosing covert (mild) thyroid disease. We compared measurements of fT4 and of normalized T4 (NT4, the effective thyroxin ratio) in a group of patients being treated for thyroid disease, most of whom were clinically euthyroid. Although fT4 values correlated well with NT4, many of the patients (34% in one...

The performance characteristics of assays is reported for thyroxine (T4), triiodothyronine (T3), and T3-uptake (T3U) using the GAMMAFLOTM Automated Assay System. A comparison of calculated free thyroxine index (FTI) values is also presented. This automated radioimmunoassay (RIA) system utilizes a combination of continuous-flow methodology and chromatographic separation techniques. The T4 assay ...

The binding of thyroxine by bovine and human serum albumin has been studied by measurements of the quenching of the ultraviolet fluorescence of the protein. The results obtained by this method have been compared with those of equilibrium dialysis measurements. Both approaches agree in assigning to serum albumin a single binding site of high affinity and three or more weak sites. The binding con...

STATEMENT OF PROBLEM The increase in the use of metal-ceramic restorations and a high prevalence of porcelain chipping entails introducing an alloy which is more compatible with porcelain and causes a stronger bond between the two. This study is to compare shear bond strength of three base-metal alloys and one noble alloy with the commonly used VMK Master Porcelain. MATERIALS AND METHOD Three...

Changes in plasma testosterone (T), thyroxine (T4), triiodothyronine (T3), semen output and remex moult were studied in domestic ganders. A bimodal pattern in both plasma T and sperm concentration was observed during the annual cycle. Ganders started to produce semen at the end of January; maximum semen volume (0.32 +/- 0.04 ml) and sperm concentration (148 +/- 38 x 10(3)/mm3) were reached in M...

A 60to 125-fold purification of nuclear extracts from rat liver triiodothyronine receptor was achieved by dialysis of 0.4 M NaCl nuclear extracts followed by chromatography on DEAE-Sephadex. Extract was labeled either by injecting tracer [““Iltriiodothyronine into the animal or by direct addition of the tracer in. vitro prior to chromatography. Elution of the column with a linear NaCl gradient ...