Thyroid hyperfunction

The main role of the human thyroid gland is production of thyroid hormones (iodinated amino acids), essential for adequate growth, development, and energy metaboHsm (1 6). Thyroid underfunction is an occurrence that can be treated successfully with thyroid preparations. In addition, the thyroid secretes calcitonin (also known as thyrocalcitonin), a polypeptide that lowers excessively high calcium blood levels. Thyroid hyperfunction, another important clinical entity, can be corrected by treatment with a variety of substances known as antithyroid dmgs. 

Artuii, F., Capula, C., Chiefari, E., Filetti, S., and Russo, D. (1998) Thyroid hyperfunctioning adenomas with and without Gsp/TSH receptor mutations show similar clinical features. Exp. Clin. Endocrinol. Diabetes. 106, 234-236. 

Thyroid hyperfunction poses a particular challenge to the thermoregu-Ltillmann, Color Atlas of Pharmacology 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 

When recently studied, tetanus toxin was shown to interact with thyroid plasma membranes.35 38 More important, the properties of this interaction were shown to closely resemble the properties of the TSH interaction with TSH receptors on these membranes the interaction of tetanus toxin with thyroid membranes exhibited several characteristics of its interaction with neural tissue tetanus toxin would not bind to membranes of a thyroid tumor with a TSH receptor defect and tetanus toxin could stimulate thyroid hyperfunction in mice subjected to conditions known to precipitate thyroid storm. 

The ability of tetanus toxin to interact with thyroid membranes and with TSH receptors on these membranes, as suggested above, has several significant implications and applications. An obvious clinical implication is that the syndrome of sympathetic overactivity which can appear in tetanus is contributed to by the ability of the toxin to induce thyroid hyperfunction. This syndrome would thus be analogous in its etiological relationship to the thyroid as is thyroid storm or as is the hypersensitivity to... 

Thyroid Hyperfunction Thyrotoxicosis is the term applied to any condition caused by elevated levels of circulating free thyroid hormones, while hyperthyroidism is restricted to those conditions in which thyroid hormone production and release are caused by gland hyperfunction. 

The Finnish workers, Roine et a/, in 1960, fed 11 Yorkshire pigs of both sexes diets containing soybean oil and HEAR oil at 28 calorie % for 60 days. No histological difference was seen between animals fed HEAR or soybean oil. A few pigs on both diets showed histological evidence of thyroid hyperfunction, interstitial myocarditis, and inflammatory reaction in the gastric mucosa. No lesions were found in the other tissues. 

Abrams and Grundy found that hypothyroid patients had a virtually normal cholesterol absorption, but that the absorbed fraction was lowered after treatment with thyroxin[127]. The authors speculated that the accelerated transit time induced by hyperthyroidism could be responsible for the reduced cholesterol absorption. To similar conclusions came Carulli et al. who studied cholesterol absorption and small bowel transit both in hyper and in hypothyroid patients[128]. The authors found that thyroid hyperfunction was associated with a very rapid intestinal transit and with a cholesterol absorption significantly lower than normal in contrast, hypothyroid patients had a very slow transit time and in 3 out of 5 cholesterol absorption was at the upper limits of normal. Furthermore, in 4 hyperthyroid patients with a low cholesterol absorption the absorbed fraction rose sharply after antithyroid therapy[129]. 

An elevated 24-hour radioactive iodine uptake (RAIU) indicates true hyperthyroidism the patient s thyroid gland is overproducing T4, T3, or both (normal RAIU 10% to 30%). Conversely, a low RAIU indicates that the excess thyroid hormone is not a consequence of thyroid gland hyperfunction but is likely caused by thyroiditis or hormone ingestion. 

Mutations with similar outcomes have been identified in nonautoimmune autosomal dominant hyperthyroidism (toxic thyroid hyperplasia) (25,26,28,32,33). These variants are located in the third TM (Val509Ala), the seventh TM (Cys672Tyr), and the carboxyl tail (Asp727Glu) regions (34). These variants result in a form of congenital hyperthyroidism that is the germline counterpart of a hyperfunctioning thyroid adenoma, with similar functional characteristics (25,33). 

In a hyperfunctioning of the thyroid gland, secretion of an excess quantity of thyroid hormones leads to a hyperthyroid condition (Basedow s disease, goiter). In this condition, drags are used that suppress production of thyrotropic hormones in the anterior lobe of the hypophysis (diiodotyrosine), in the thyroid gland (propylthiouracil, methylthiouracil,... 

Methimazole also directly disrupts thyroxine and triiodothyronin sysnthesis in the thyroid gland, and it is used for the same indications as propylthiouracil and methylthiouracil to treat hyperfunctioning thyroid glands in patients with Basedow s disease. Synonyms of this drug are merazolil, thiamazole, metothyrin, timidazol, and others. 

While hypofunction of the thyroid gland is relatively common, hyperfunction is an uncommon illness affecting less than 0.25 percent of the population. It is more prevalent among females than males (8 1) and usually occurs in middle age it rarely occurs in children or adolescents. Hyperfunction of the thyroid gland is known as Graves disease, after the Irish physician who was one of the first to fully describe the syndrome. 

Derivatives of 6-methyl-2-thiouracil (I) are widely used, as medical products for treatment virus HSV-1 [1, 2], hyperfunctions of a thyroid gland [3], illnesses Huntington, Parkinson, migraines, depressions, infringements of memory [4], Derivatives 2-thiouracil are inhibitors of human immunodeficiency vims revers transcriptase of type (HIV-1) and show powerful inhibitiones properties in attitude HIV-1 in vitro [5-18], One of the most developed... 

These germ-line variants, resulting in a form of congenital hyperthyroidism, share similar functional characteristics somatic mutations present in hyperfunctioning thyroid adenoma [24, 32],... 

G. N. Burrow Thyroid function and hyperfunction during gestation. Endocrine Review 14, 194 (1993). 

Parma, J., Duprez, L., Van sande, J., Cochaux, P., Gervy, C., Mockel, J., Dumont, J., Vassart, G., 1993. Somatic mutations in the thyrotropin receptor gene cause hyperfunctioning thyroid adenomas. Nature 365, 649-651,... 

Notes-. 184 cases of hyperfunctioning thyroid adenoma, adenomatous nodules, or carcinomas listed in the TSHR Mutation Database II (http //www.uni-leipzig.de/ innereAsh/) were studied for their base exchanges. 

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