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Concept: Thyroid disease

172

The endocrine system and particular endocrine organs, including the thyroid, undergo important functional changes during aging. The prevalence of thyroid disorders increases with age and numerous morphological and physiological changes of the thyroid gland during the process of aging are well-known. It is to be stressed that the clinical course of thyroid diseases in the elderly differs essentially from that observed in younger individuals, because symptoms are more subtle and are often attributed to normal aging. Subclinical hypo- and hyperthyroidism, as well as thyroid neoplasms, require special attention in elderly subjects. Intriguingly, decreased thyroid function, as well as thyrotropin (TSH) levels – progressively shifting to higher values with age – may contribute to the increased lifespan.This short review focuses on recent findings concerning the alterations in thyroid function during aging, including these which may potentially lead to extended longevity, both in humans and animals.

Concepts: Thyroid disease, Hypothyroidism, Hashimoto's thyroiditis, Hyperthyroidism, Thyroid, Graves' disease, Endocrine system, Triiodothyronine

171

Autoimmune thyroid disease (AITD), including Graves' disease (GD) and Hashimoto’s thyroiditis (HT), is one of the most common of the immune-mediated diseases. To further investigate the genetic determinants of AITD, we conducted an association study using a custom-made single-nucleotide polymorphism (SNP) array, the ImmunoChip. The SNP array contains all known and genotype-able SNPs across 186 distinct susceptibility loci associated with one or more immune-mediated diseases. After stringent quality control, we analysed 103 875 common SNPs (minor allele frequency >0.05) in 2285 GD and 462 HT patients and 9364 controls. We found evidence for seven new AITD risk loci (P < 1.12 × 10(-6); a permutation test derived significance threshold), five at locations previously associated and two at locations awaiting confirmation, with other immune-mediated diseases.

Concepts: Bioinformatics, Single-nucleotide polymorphism, Thyroid disease, Genetic genealogy, Hashimoto's thyroiditis, Hyperthyroidism, Thyroid, Minor allele frequency

168

BACKGROUND: We would like to investigate the if IMRT produced better target coverage and dose sparing to adjacent normal structures as compared with 3DCRT and LOF for patients with Graves' ophthalmopathy treated with retro-orbital irradiation. METHODS: Ten consecutive patients diagnosed with Graves' ophthalmopathy were prospectively recruited into this study. An individual IMRT, 3DCRT and LOF plan was created for each patient. Conformity index (CI), homogeneity index (HI) and other dosimetric parameters of the targets and organs-at-risk (OAR) generated by IMRT were compared with the other two techniques. RESULTS: Mann–Whitney U test demonstrated that CI generated by IMRT was superior to that produced by 3DCRT and LOF (p=0.005 for both respectively). Similarly HI with IMRT was proven better than 3DCRT (p=0.007) and LOF (p=0.005). IMRT gave rise to better dose sparing to some OARs including globes, lenses and optic nerves as compared with 3DCRT but not with LOF. CONCLUSIONS: IMRT, as compared with 3DCRT and LOF, was found to have a better target coverage, conformity and homogeneity and dose sparing to some surrounding structures, despite a slight increase but clinically negligible dose to other structures. Dosimetrically it might be a preferred treatment technique and a longer follow up is warranted to establish its role in routine clinical use.

Concepts: Hospital, Thyroid disease, Hyperthyroidism, Target Corporation, Graves' ophthalmopathy

80

 To estimate the effectiveness and safety of thyroid hormone treatment among pregnant women with subclinical hypothyroidism.

Concepts: Childbirth, Prolactin, Thyroid disease, Constipation, Hypothyroidism, Hyperthyroidism, Thyroid, Thyroid hormone

61

Although growing evidence points to highly indolent behavior of encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC), most patients with EFVPTC are treated as having conventional thyroid cancer.

Concepts: Cancer, Oncology, Types of cancer, Thyroid disease

33

A 21-year-old woman with thyroid carcinoma underwent thyroidectomy and lymph-node dissection. Two days later, she had forced extension of the neck, nonrigid opening of the jaw, and deviation of the eyes. Videos show the reaction and the resolution after treatment with biperiden.

Concepts: Thyroid disease, Dystonia

28

AIMS: Understanding the exact relationship between serum thyrotropin/thyroid stimulating hormone (TSH) and free thyroxine (FT(4)) is a prerequisite for improving diagnostic reliability and clinical decision making. METHODS: We (1) retrospectively studied the relationship between TSH and FT(4) in a large unselected clinical sample (n=6641) of primary hypothyroid, euthyroid and hyperthyroid subjects, and (2) applied a mathematical model of thyroid hormone feedback control to assess the relation between structural parameters and TSH levels in the different functional states. RESULTS: When separately analysing total sample and untreated subjects, the correlation slope for logTSH versus FT(4) for hypothyroid subjects was significantly different from that of the euthyroid panel and hyperthyroid subjects (the latter being compromised by reaching the TSH assay’s lower detection limit). As trends between functional states changed, each functional segment appeared to become differently regulated. Theoretical modelling and sensitivity analysis revealed that the influence of various structural parameters on TSH levels also depends on the overall function of the feedback loop. CONCLUSIONS: Our data suggest that the states of hypothyroidism, euthyroidism and hyperthyroidism can be regarded as differently regulated entities. The apparent complexity could be replicated by mathematical modelling suggesting a hierarchical type of feedback regulation involving patterns of operative mechanisms unique to each condition. For clinical purposes and assay evaluation, neither the standard model relating logTSH with FT(4), nor an alternative model based on non-competitive inhibition can be reliably represented by a single correlation comparing all samples for both hormones in one all-inclusive group.

Concepts: Physics, Thyroid-stimulating hormone, Thyroid disease, Hypothyroidism, Hyperthyroidism, Thyroid, Thyroid hormone, Triiodothyronine

28

Studies on the role of thyroid hormones (THs) in teleost fish physiology have deployed the synthetic goitrogens, methimazol (MMI), propilthiouracil (PTU) and thiourea (TU) that are used to treat human hyperthyroidism. However, the action of the goitrogens, MMI, PTU and TU at different levels of the hypothalamic-pituitary-thyroid (HPT) axis in teleosts is largely unknown. The central importance of the hypothalamus and pituitary in a number of endocrine regulated systems and the cross-talk that occurs between different endocrine axes makes it pertinent to characterize the effects of MMI, PTU and TU, on several endpoints of the thyroid system. The marine teleost, sea bream (Sparus auratus) was exposed to MMI, PTU and TU (1mg/kg wet weight per day), via the diet for 21days. Radioimmunoassays (RIA) of plasma THs and ELISA of the TH carrier transthyretin (TTR) revealed that MMI was the only chemical that significantly reduced plasma TH levels (p<0.05), although both MMI and PTU significantly (p<0.05) reduced plasma levels of circulating TTR (p<0.05). Histological analysis of the thyroid tissue revealed modifications in thyrocyte activity that explain the reduced circulating levels of THs. MMI also significantly (p<0.05) up-regulated transcript abundance of liver deiodinase 1 and 2 while significantly (p<0.05) decreasing TRβ expression in the pituitary, all hallmarks of HPT axis action of goitrogens in vertebrates. The results indicate that in the sea bream MMI is the most effective goitrogen followed by PTU and that TU (1mg/kg wet weight for 21days) failed to have a goitrogenic effect. The study highlights the non-uniform effect of goitrogens on the thyroid axis of sea bream and provides the basis for future studies of thyroid disrupting pollutants.

Concepts: Thyroid disease, Hyperthyroidism, Thyroid, Endocrine system, Actinopterygii, Goitrogen, Teleostei, Goitrin

28

Anaplastic thyroid cancer (ATC) is an aggressive neoplasm for which a paucity of data exist about the relative role of operative procedures in disease management.

Concepts: Epidemiology, Cancer, Oncology, Patient, Types of cancer, Thyroid disease

28

Carcinomas arising in the thyroglossal duct cysts are rare, accounting only for about 0.7-1.5 % of all thyroglossal duct cysts.1 (-) 3 Synchronous occurrence of thyroglossal duct carcinoma and thyroid carcinoma is reported to be even rarer.4 Traditionally, surgical treatments of such coexisting thyroglossal duct cyst carcinoma (TGDCa) and papillary thyroid carcinoma (PTC) were typically performed through a single transverse or double incisions on the overlying skin. A longer, extended cervical incision might be required if neck dissection is necessary. Though this method provides the operator with the optimal surgical view, the detrimental cosmetic effect on the patient of possessing a scar cannot be avoided, despite the effort of the surgeon to camouflage the scar by placing the incision in natural skin creases. Recently, the authors have previously reported the feasibility of robot-assisted neck dissections via a transaxillary and retroauricular (“TARA”) approach or modified face-lift approach in early head and neck cancers.5 (,) 6 On the basis of the forementioned surgical technique, we demonstrate our novel technique for robot-assisted Sistrunk’s operation via retroauricular approach as well as robot-assisted neck dissection with total thyroidectomy via transaxillary approach.

Concepts: Head and neck, Surgery, Epithelium, Thyroid disease, Al-Andalus, Surgical oncology, Otolaryngology, Thyroglossal cyst