Journal of Thyroid Research最新文献

Exosomes are 30-100 nm, membrane-bound vesicles containing specific cellular proteins, mRNAs, and microRNAs that take part in intercellular communication between cells. A possible role for exosomes in thyroid function has not been fully explored. In the present study, FRTL-5 rat thyroid cells were grown to confluence and received medium containing either thyroid stimulating hormone (TSH), exogenous bovine thyroglobulin (bTg), or neither additive for 24 or 48 hours followed by collection of spent medium and ultracentrifugation to isolate small vesicles. Transmission electron microscopy and Western blotting for CD9 indicated the presence of exosomes. Western blotting of exosome extract using a monoclonal anti-Tg antibody revealed a Tg-positive band at ~330 kDa (the expected size of monomeric Tg) with a higher density in TSH-treated cells compared to that in untreated cells. These results are the first to show that normal thyroid cells in culture produce exosomes containing undegraded Tg.

Background. Regional lymph node recurrence (RLNR) is common in patients with thyroid cancer but clinicopathological predictors are unclear. We aimed to clarify these predictors and identify patients who would benefit from prophylactic lymph node dissection the most. Method. 343 patients with different types of thyroid cancer were analyzed retrospectively. All patients underwent total thyroidectomy between 2007 and 2013. Results. The median ± interquartile range of patients' age was 40 ± 25 years. 245 (71.4%) patients were female. Regarding the risk of regional lymph node recurrence, we found that male gender, age ≥45 years, non-PTC (i.e., medullary, follicular, and anaplastic types) histopathology, T3 (i.e., tumor size >4 cm in the greatest dimension limited to the thyroid or any tumor with minimal extrathyroid extension), stage IVa, and isolated cervical lymphadenopathy as initial manifestation (ICL) are significant risk factors. T3 (p < 0.001; odds ratio = 156.41, 95% CI [55.72-439.1]) and ICL (p < 0.001; odds ratio = 77.79, 95% CI [31.55-191.81]) were the strongest predictors of regional lymph node recurrence. Conclusion. We found easily achievable risk factors for RLNR in thyroid cancers patients. We suggested that patients with specific clinicopathological features like male gender, age ≥45 years, larger tumor size, and extrathyroidal extension be considered as prophylactic lymphadenectomy candidates.

According to the epidemiological studies, about 4.4% of American general elderly population has a pronounced hypothyroidism and relies on thyroid hormone supplements daily. The prevalence of hypothyroidism in our patients with pancreatic cancer was much higher, 14.1%. A retrospective analysis was performed on patients who underwent pancreaticoduodenectomy (Whipple procedure) or distal pancreatectomy and splenectomy (DPS) at Thomas Jefferson University Hospital, Philadelphia, from 2005 to 2012. The diagnosis of hypothyroidism was correlated with clinicopathologic parameters including tumor stage, grade, and survival. To further understand how thyroid hormone affects pancreatic cancer behavior, functional studies including wound-induced cell migration, proliferation, and invasion were performed on pancreatic cancer cell lines, MiaPaCa-2 and AsPC-1. We found that hypothyroid patients taking exogenous thyroid hormone were more than three times likely to have perineural invasion, and about twice as likely to have higher T stage, nodal spread, and overall poorer prognostic stage (P < 0.05). Pancreatic cancer cell line studies demonstrated that exogenous thyroid hormone treatment increased cell proliferation, migration, and invasion (P < 0.05). We conclude that exogenous thyroid hormone may contribute to the progression of pancreatic cancer.

Background. Tumor multifocality and bilaterality of papillary thyroid carcinoma (PTC) are important factors when selecting the most appropriate surgical procedure. The aim of this study was to assess the bilaterality rate in PTC and the relationship between the tumor size and bilaterality. Materials and Methods. Thyroidectomy specimens with a diagnosis of PTC were retrospectively reviewed in the Pathology Department of a tertiary care medical center. Specimens were divided into three groups according to the size of the primary and contralateral tumor foci. Tumors less than or equal to 1 cm in each lobe were included in group 1. Group 2 consisted of tumors greater than 1 cm in one lobe and less than 1 cm in the other lobe. Tumors greater than 1 cm in each lobe were included in group 3. Results. We identified 868 total thyroidectomy specimens with a diagnosis of PTC between 2001 and 2011. Of these cases, both thyroid lobes were involved in 262 cases (32%). There were 109 (42%), 121 (46%), and 32 cases (12%) in group 1, group 2, and group 3, respectively. Conclusion. Bilaterality is frequent in PTC and is not related to tumor size. Accordingly, the high frequency of bilateral disease in PTC should be kept in mind when determining the extent of the surgical procedure.

Background. Studies on bone effects of long-term substitution therapy with levothyroxine (LT4) have shown discrepant results. Previous studies have, however, not evaluated volumetric bone mineral densities (vBMD), bone structure, and strength using high resolution peripheral quantitative computed tomography (HR-pQCT) and finite element analysis (FEA). Using a cross-sectional design, we aimed to determine whether BMD, structure, and strength are affected in hypothyroid patients on LT4 substitution therapy. Methods. We compared 49 patients with well-substituted hypothyroidism with 49 age- and gender-matched population based controls. Areal BMD was assessed by DXA, vBMD and bone geometry by HR-pQCT, and bone strength by FEA. Results. Patients had been thyroidectomized due to thyroid cancer (10%) and nontoxic (33%) or toxic goiter (57%). 82% were women. TSH levels did not differ between groups, but patients had significantly higher levels of T4 (p < 0.001) and lower levels of T3 (p < 0.01). Compared to controls, patients had higher levels of magnesium (p < 0.05), whereas ionized calcium and PTH were lower (p < 0.05). Bone scans did not reveal any differences in BMD, bone geometry, or strength. Conclusion. If patients with hypothyroidism are well-substituted with LT4, the disease does not affect bone indices to any major degree.