Short-term experimental diabetes mellitus (DM) produces a significant decrease in serum thyroid hormones, a decreased or normal serum thyroid-stimulating hormone (TSH) and a reduction in hepatic and renal T4-5'-deiodination. However, little is known about the effects of chronic diabetes mellitus on the pituitary-thyroid axis function. We evaluated the changes induced by very short-term (6 days)...

crease in T4 secretion induced by iodine is not the result of an acute, sustained inhibition of T4 synthesis, but rather results from an abrupt decrease in the fractional rate of thyroidal T4 release.

The genomes of petite T4 phage particles presumably cannot circularize because they are deficient for a significant terminal segment and hence not terminally redundant like normal T4 genomes. Combined density- and 32P-labeling shows that the majority of such deficient DNA molecules can nevertheless replicate their entire length. Furthermore, the density-shift technique shows that replicated par...

Integration deficient (L) mutants of phage P22 can be complemented with L+ phage to yield L mutant lysogens. Once established the L prophage is stable in the absence of L+ function. Ultraviolet or thermal induction of L lysogens leads to product,ion of defective phage particles and low yields of infectious phage. The defective particles contain a normal amount of DNA but the DNA is mainly bacte...

A 28 year old woman with Hashimoto's disease was treated with desiccated thyroid and triiodothyronine (T3). She improved steadily during the first 2 to 3 months and thyroidal function tests turned to normal. Then, in spite of continuing treatment, her serum T4 level decreased gradually and she became fatigued. A serum T3 radioimmunoassay manifested an interference pattern suggested anti-T3 anti...

To study thyroid hormone and estrogen interactions in the central nervous system (CNS), the expression of estrogen sensitive genes was examined within the limbic-hypothalamic circuit. Estrogen up-regulates the expression of reproductively relevant neuropeptide messenger RNAs (mRNAs) encoding cholecystokinin (CCK) and enkephalin, peptides that stimulate lordosis. Estrogen down-regulates the expr...

CONTEXT Familial dysalbuminemic hyperthyroxinemia, characterized by abnormal circulating albumin with increased T4 affinity, causes artefactual elevation of free T4 concentrations in euthyroid individuals. OBJECTIVE Four unrelated index cases with discordant thyroid function tests in different assay platforms were investigated. DESIGN AND RESULTS Laboratory biochemical assessment, radiolabe...

Background. Recently, it has been shown that liquid L-T4 formulation can be ingested with breakfast. This study looked to extend these findings by investigating whether a soft gel capsule formulation of L-T4 could also be ingested at breakfast time. Methods. 60 patients (18-65 yrs), previously submitted to thyroidectomy for proven benign goitre in stable euthyroidism receiving liquid L-T4 thera...

Bacteriophage T4 encodes most of the genes whose products are required for its DNA metabolism, and host (Escherichia coli) genes can only infrequently complement mutationally inactivated T4 genes. We screened the following host mutator mutations for effects on spontaneous mutation rates in T4: mutT (destruction of aberrant dGTPs), polA, polB and polC (DNA polymerases), dnaQ (exonucleolytic proo...

BACKGROUND L-thyroxine (L-T4) malabsorption is a potential concern in patients with autoimmune atrophic gastritis. METHODS We evaluated five patients with autoimmune gastritis, who showed high serum thyrotropin (TSH) levels (in the hypothyroid range) while in therapy with L-T4 in tablet. All patients were switched to receive an oral L-T4 liquid formulation maintaining the same dosage. RESUL...