Thyroid gland, function

Thyrotoxicosis factitia should be suspected in a thyrotoxic patient without evidence of increased hormone production, thyroidal inflammation, or ectopic thyroid tissue. The RAIU is low because thyroid gland function is suppressed by the exogenous thyroid hormone. Measurement of plasma thyroglobulin reveals the presence of very low levels. 

In the second paragraph, the thyroid gland function is mentioned as slowing down—one effort on the part of the body to protect itself According to the second paragraph, dehydration contributes to constipation. 

Raldua D, Babin PJ (2009) Simple, rapid zebrafish larva bioassay for assessing the potential of chemical pollutants and dmgs to dismpt thyroid gland function. Environ Sci Technol 43 6844-6850... 

Disrupting Effects of Single and Combined Emerging Pollutants on Thyroid Gland Function... 

Keywords Goitrogens, Thyroid follicle, Thyroid gland, Thyroid gland function dismptor, Thyroid hormone, Zebrafish... 

Zebrafish A Vertebrate Model for Screening Thyroid Gland Function Disrupters.. 421... 

Fig. 1 Thyroid hormone synthesis in a thyroid follicular cell. NIS and TPO (organification and coupling reaction) have been marked in red dashed line as the two main targets for direct thyroid gland function disrupters. DEHALl iodotyrosine dehalogenase 1, DIT diiodotyrosine, DUOX2 dual oxidase 2, MIT monoiodotyrosine, Na/K-ATPase sodium-potassium ATPase, NIS sodium-iodide symporter, PSD pendrin, TG thyroglobulin, TPO thyroperoxidase. Reprinted from [7] with permission from Elsevier...

Fig. 5 Heat-map summarizing mammalian versus zebrafish eleutheroembryo responses using 16 known or suspected direct-TGFDs with different modes of action. Red indicates thyroid gland function disrupting activity Green indicates that the chemical is not a TGFD...

IT4C, which emphasizes the risk for the thyroid gland function of the mixture of chemicals with thyroid disrupting activity. 

In summary, our data provide evidence for the suitability of zebrafish eleuther-oembryos as a predictive vertebrate model for evaluating the effect of individual chemicals and mixtures on thyroid gland function. TIQDT performed on zebrafish eleutheroembryos is an alternative whole-organism screening assay that provides relevant information for environmental and human risk assessments. 

Clinical use of amiodarone is limited because of its high toxicity, which consists of cardiac block, bradycardia, cardiac insufficiency, damaged thyroid gland function, neuropathology, and increased sensitivity to light, all of which significantly limit use of amiodarona, and it is only used in therapy for extremely serious tachyarrhythmias such as reoccurring ventricular fibrillation and hemodynamic unstable ventricular tachycardia, and only under supervision of a physician in a clinical situation. Synonyms of amiodarone are cordarone, rythmarone, and others. 

Iodine concentrations in breast milk and in random urine in neonates and the serum concentrations of neonatal TSH and free thyroxine on day 5 after delivery were measured after the use of povidone-iodine for disinfection after delivery (36). Iodine concentrations in the breast milk and neonatal TSH were significantly raised. Perinatal iodine exposure causes transient hypothyroidism in a significant number of neonates, in whom careful monitoring and follow-up of thyroid gland function are needed. It is better to avoid the use of iodine-containing antiseptics in pregnancy and neonates, especially if follow-up cannot be guaranteed. 

Madej A, Persson E, Lundh T, Ridderstrale Y. 2002. Thyroid gland function in ovariectomized ewes exposed to phytoestrogens. J Chromatogr B Analyt Technol Biomed Life Sci 777 281-287. 

Thyroid gland function also regulates calcitonin which combats elevated levels of calcium. 

There are numerous thyroid gland function tests, each designed to determine the etiology of thyroid dysfunction. In general, though, when hypothyroidism is present, circulating T3 and T4 levels are down and TSH is up. The opposite is true of hyperthyroidism. In addition, free (non-protein-bound) T4 and TBG may be determined to clarify inconclusive results. In hyperthyroidism, free T4 is increased but total T4 may be normal. It is the free serum T4 that has been correlated with clinical symptoms rather than total T4. 

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