We assessed a commercial kit (Corning Medical) for "free" and total thyroxine determination, results being compared to those obtained by the Ekins and Ellis dialysis method (free thyroxine) and the method of Weeke and Orskov (total thyroxine). The kit procedure permits determination of both free and total thyroxine within 4 to 5 h, and the combined results may disclose changes in binding to pl...

In order to evaluate the influence of thyroxine treatment on thyroid volume after thyroidectomy for non-toxic goitre 110 consecutive patients were randomised to receive thyroxine (150 micrograms daily) or no treatment three months after operation. Thyroid volume determined by ultrasonography did not differ significantly between the two groups one year after operation. Nevertheless, a similar de...

Woolley (1) has prepared a number of ethers of N-acetyl-3,5-diiodotyrosine and found them to interfere with various effects of thyroxine on amphibian larvae. Some of Woolley’s observations were confirmed and extended by Winder and Frieden (2) and by Williams et al. (3). It is the purpose of this report to investigate the competitive nature of several thyroxine inhibitors and to determine the st...

The effect of isoflurane (Forane) anaesthesia and surgery on thyroid function was investigated in nine male patients. Isoflurane anaesthesia alone for 30 minutes prior to the start of surgery increased plasma triiodothyronine uptake (T3U) and thyroxine (T4) level by 18 and 20 per cent, respectively. Free thyroxine index (FTI) values in blood increased by 62 per cent during the same period. One ...

The increased requirement for vitamin Blz in thyrotoxic animals is well established (l-3). Vitale et al. (4) have demonstrated that magnesium will also partially overcome the growth-inhibiting action of thyroxine administration. Uncoupling of oxidative phosphorylation occurs in rats made magnesium-deficient either by dietary deprivation of magnesium (5) or by thyroxine administration (4). In vi...

In the late 1980s, the Austrian biologists Christian Endler and Waltraud SchererePongratz, based at the time at the Zoological Institute of Graz University and the Boltzmann Institute Graz, picked up a long-forgotten line of research on amphibian metamorphosis and homeopathic potencies. Rather than merely replicate K€onig’s original experiments conducted in the 1920s, using metal salts they cho...

The hypothalamic content and concentration of thyrotropin-releasing hormone (TRH) were determined by radioimmunoassay in normal, thyroidectomized, hypophysectomized and cold-exposed rats with or without thyroxine. In normal animals, the single administration of thyroxine (1,5 and 20 microgram/100 g B.W.) altered neither the content nor the concentration of TRH in the hypothalamus. However, seve...

Nephrotic syndrome increases L-thyroxine requirements because of urinary loss of free and protein-bound thyroid hormones. We report 2 hypothyroid patients referred to us because of high serum TSH, even though the L-thyroxine daily dose was maintained at appropriate levels or was increased. The cause of nephrotic syndrome was multiple myeloma in one patient and diabetic glomerulosclerosis in the...

To evaluate cardiovascular functionality in patients with thyroid cancer, we have performed echocardiography and ambulatory blood pressure monitoring in 19 women with differentiated thyroid carcinoma during thyroxine withdrawal, at three time points: the last day on TSH-suppressive thyroxine doses (subclinical or mild hyperthyroidism), 4-7 days after withdrawal (normal free thyroxine (FT4) and ...

In previous work from this laboratory (1) studies on equilibrium dialysis were carried out to determine the binding constants for the interaction of human serum albumin with thyroxine and its analogs. The classical technique of equilibrium dialysis as described by Scatchard and others (2-6) was employed. At present it seems clear that thyroxine in human serum migrates to at least three differen...