Editor—We read with great interest the article by Nitahara and colleagues showing concentration-dependent inhibitory effects of sevoflurane on neuromuscular transmission in myasthenia gravis (MG) patients which was more prominent in patients with a pre-anaesthetic T4/T1,0.9. In their study, T4/T1 returned to baseline value in all patients at the end of anaesthesia. The importance of monitoring ...

Several influences modulate biochemical responses to a weight-adjusted levothyroxine (l-T4) replacement dose. We conducted a secondary analysis of the relationship of l-T4 dose to TSH and free T3 (FT3), using a prospective observational study examining the interacting equilibria between thyroid parameters. We studied 353 patients on steady-state l-T4 replacement for autoimmune thyroiditis or af...

It is over 40 years since the original demonstration that thyroxine (T4), the principal secretory product of the thyroid, is deiodinated, to 3,5,3'-tri-iodothyronine (T3) in peripheral mammalian tissues. Subsequently it was shown that the antithyroid drug propylthiouracil (PTU) also blocked the metabolic effects of administered T4 in proportion to its inhibition of T4 to T3 conversion, indicati...

A new method for the estimation of the maximal T4-binding capacity of TBG (max. TBG) in serum (dextran-coated charcoal-triosorb method) was devised. Thyroxine (T4) concentration in test sera were determined by the Tetrasorb method and then T3 resin sponge uptake (T3 RSU) was determined after extraction of 70% of the endogenous T4 with dextran-coated charcoal. The binding capacity of unsaturate...

BACKGROUND Total or near-total thyroidectomy is increasingly used to treat benign thyroid conditions. Lifelong treatment with thyroxine (T4) is then required, but the optimal dose is difficult to predict. This study investigated factors that might predict the ideal T4 dose, with the aim of reducing delays in achieving normal thyroid function after surgery. METHODS Data on 98 patients who unde...

Thyroid hormones (THs) play a vital role in vertebrate neural development, and, together with the beta isoform of the thyroid hormone receptor (TRβ), the development and differentiation of cone photoreceptors in the vertebrate retina. Rainbow trout undergo a natural process of cone cell degeneration during development and this change in photoreceptor distribution is regulated by thyroxine (T4; ...

Experimental and clinical observations suggest that thyroid hormone [L-thyroxine (T4) and 3,5,30-triiodo-Lthyronine (T3)] can support cancer cell proliferation. T3 and T4 promote both tumor cell division and angiogenesis by activating mitogen-activated protein kinase (MAPK) via binding to a hormone receptor on the avb3 integrin, overexpressed on many cancer cells. We have studied the responsive...

Viral metagenomics (viromics) is a tremendous tool to reveal viral taxonomic and functional diversity across ecosystems ranging from the human gut to the world's oceans. As with microbes however, there appear vast swaths of "dark matter" yet to be documented for viruses, even among relatively well-studied viral types. Here, we use viromics to explore the "Far-T4 phages" sequence space, a neighb...

We hypothesized that nitric oxide generated by inducible nitric oxide synthase (iNOS) may contribute to the homeostatic role of this agent in hyperthyroidism and may, therefore, participate in long-term control of blood pressure (BP). The effects of chronic iNOS inhibition by oral aminoguanidine (AG) administration on BP and morphological and renal variables in hyperthyroid rats were analyzed. ...