We describe a patient whose serum gave consistently low results for thyroxin as measured with the Abbott TDx but normal results by radioimmunoassay. Further clinical and laboratory studies did not support the low TDx results. Anti-thyroxin antibodies did not explain the discordant results, and we found no evidence of heterophilic antibodies in the patient's serum. We were unable to identify the...

Free thyroxin (FT4) concentrations, total thyroxin/thyroxin-binding globulin (T4/TBG) ratios, and thyrotropin (TSH) and albumin concentrations were measured in serum in a longitudinal study in each of the three trimesters of 25 normal pregnancies. In late pregnancy, FT4 estimates by assays reputedly either affected or unaffected by albumin were in the lower half of the reference range for nonpr...

Background: Subclinical hypothyroidism (SCH) is mild-to-moderate thyroid insufficiency that is characterized by thyrotropin (TSH) level higher than the upper limit despite normal serum free thyroxin (fT4) level. Likewise, SCH as well might be a risk factor for cardiovascular diseases. Some placebocontrolled studies showed beneficial effect of L-thyroxin replacement on the risk for early atheros...

We compared the clinical value of "Amerlex" (Amersham International) and "Pre-release Coat-A-Count" (Diagnostic Products Corp.) radioimmunoassay kits for free triiodothyronine with that of triiodothyronine, triiodothyronine/thyroxin-binding globulin ratio, and free triiodothyronine index in patients with thyroid disease, pregnant women, oral contraceptive users, thyroxin-binding globulin-defici...

OBJECTIVES: Approximately 20% of BALB/cCF mice are born with partial or total absence of the corpus callosum. Here, we analyzed testosterone and free thyroxin blood levels in adult male mice of this strain in order to see if these hormones are related to the incidence of callosal defects. METHODS: Blood collected from the axillary blood vessels of 12 normal and 10 acallosal deeply anesthetized ...

Previous results are contradictory regarding the concentration of thyroxin in human milk. Using a sensitive radioimmunoassay, we have found a lack of parallelism between the standard curve for thyroxin and the curve for serial dilutions of whole human milk, skimmed milk, or ethanol extracts of milk. Nonspecific binding also indicated the presence of analytical artifacts. Thus we have separated ...

AIM Research shows that subclinical hypothyroidism (SCH) is related to an increased carotid intima-media thickness (CIMT), a surrogate marker of subclinical cardiovascular disease (CVD). It is controversial whether or not SCH should be treated to reduce CVD morbidity and mortality. This meta-analysis aimed to determine whether SCH is associated with an increase in CIMT as compared to Euthyroidi...

We performed a limited evaluation of four free thyroxin (FT4) reagent kits: the Amerlex-M (AFT4), the Amerlite (LFT4), the MagicLite (MFT4), and the GammaCoat two-step RIA (GFT4). FT4 was measured in specimens from 201 subjects: 19 healthy controls, 14 patients who were thyrotoxic, 13 who were hypothyroid, 59 who had a past history of thyroid disease, seven with thyroxin autoantibodies, seven w...