Blind hamsters had no alteration of the dialyzable fraction of serum thyroxine (T4) but had depressed total and free T4 concentrations compared to controls. Prevention of the effects of blinding by pinealectomy indicates pineal influence on circulating free T4 concentration. Parallel changes in free T4 and the free T4 index indicate adequacy of the index in representing pineal-induced changes i...

There have been, and continue to be, reports of discordant free thyroxine (T4) 3 measurements when different free-T4 methods are applied to the same serum samples (1– 4 ). Our laboratory has attempted to identify some of the factors that contribute to these disparities. There are 4 separate components of serum T4: free T4, albumin-bound T4, transthyretin-bound T4, and thyroxine-binding globulin...

1. Effects of endosulfan, malathion and carbaryl on circulating T4, T3 and T3/T4 ratio in the freshwater catfish, C. batrachus have been studied during reproductively active phases, i.e. vitellogenic and post-vitellogenic phases of its annual reproductive cycle. 2. Endosulfan provoked a significant increase in T4 and a decrease in T3 as well as the T3/T4 ratio. 3. Malathion decreased T3 and T3/...

We study constructions and classifications of three-generation models based on magnetized $T^4$ $T^4/{Z}_2$ orbifold as candidates the compact space. focus chiral fermion zero-mode wave functions in extra dimensions. Freedoms constant gauge fields, called Scherk-Schwarz phases are taken into account. Infinite number yielded, corresponding to ways which magnetic flux can be turned on. classify t...

OBJECTIVE To determine a levothyroxine (T4) dose recommendation for the treatment of autoimmune thyroiditis (AIT)-induced hypothyroidism. METHODS T4 doses in 75 children and adolescents with newly diagnosed AIT were prospectively collected and compared to T4 doses of patients with congenital hypothyroidism (CH, n=22). RESULTS Sixty-four patients with AIT and 22 patients with CH were include...

Serum free thyroxin (FT4) was determined in 40 patients with various nonthyroidal illnesses. We studied seven methods: (1) a free thyroxin index calculated from total T4 and triiodothyronine resin uptake; (2) a free T4 index determined by enzyme inhibitor assays (Abbott's "Tetrazyme" and "Thyrozyme"); (3) a free T4 index calculated from total T4 and thyroxin-binding globulin; (4) free T4 by equ...

Excessive bias and imprecision are major analytical problems associated with some assays for free and total thyroxine (T4). Bias in free T4 methods is largely proportional to variations in serum T4 binding. In direct methods, this is attributable to requirements for substantial quantities of protein-bound T4 to replace analytical losses of free T4. In some total T4 methods, bias is inversely pr...