The role of a new polyclonal competitive thyroglobulin assay in the follow-up of patients with differentiated thyroid cancer with structural disease but low levels of serum thyroglobulin by immunometric and LC-MS/MS methods.

Purpose: The aims of this study were to assess the role of an in-house competitive thyroglobulin assay (Tg-c) in the follow-up of metastatic differentiated thyroid carcinoma (DTC) patients who presented underestimated Tg measurements by immunometric assays (Tg-IMA) and to compare the results with IMA and LC-MS/MS Tg methods.

Methods: This prospective study included 40 patients. Twenty-one with metastatic disease: 14 had Tg-IMA levels inappropriately low or undetectable (eight patients with positive and six with borderline TgAb) and seven had high Tg-IMA levels.

Novel immunoassay for TSH measurement in rats.

Measuring thyroid hormones is an important aspect for the study of metabolism and for monitoring diseases in both human and animal models. The traditional method for hormone measurement in rats is the radioimmunoassay (RIA). However, the RIA is associated with some practical disadvantages, including the use of radioactive material, the need for specialized equipment and expert staff, the short shelf-life of kits according to the half-life of the radioisotope and high costs.

Prevalence of pancreatic autoantibodies in non-diabetic patients with autoimmune thyroid disease and its relation to insulin secretion and glucose tolerance.

Objective: We evaluated the prevalence of glutamic acid decarboxylase (GADA) and tyrosine phosphatase-protein antibodies (IA2A), their titers and their relation to first phase insulin response (FPIR) and glucose tolerance in autoimmune thyroid diseases (ATDs) patients.

Subjects And Methods: Graves' disease (GD; n = 181) and Hashimoto's thyroiditis (HT; n = 143) patients in addition to healthy controls (n = 93) were studied. Secondly, FPIR and oral glucose tolerance tests (OGTT) were performed in 11 anti-pancreatic islet-cell (+) and in 20 anti-pancreatic-cell (-) patients.

Clinical impact of thyroglobulin (Tg) and Tg autoantibody (TgAb) measurements in needle washouts of neck lymph node biopsies in the management of patients with papillary thyroid carcinoma.

Objectives: The presence of thyroglobulin (Tg) in needle washouts of fine needle aspiration biopsy (Tg-FNAB) in neck lymph nodes (LNs) suspected of metastasis has become a cornerstone in the follow-up of patients with papillary thyroid carcinoma (PTC). However, there are limited data regarding the measurement of anti-Tg antibodies in these washouts (TgAb-FNAB), and it is not clear whether these antibodies interfere with the assessment of Tg-FNAB or whether there are other factors that would more consistently justify the finding of low Tg-FNAB in metastatic LNs.

Materials And Methods: We investigated 232 FNAB samples obtained from suspicious neck LNs of 144 PTC patients.

M918V RET mutation causes familial medullary thyroid carcinoma: study of 8 affected kindreds.

Germline mutations in codon 918 of exon 16 of the RET gene (M918T) are classically associated with multiple endocrine neoplasia type 2B (MEN 2B) with highly aggressive medullary thyroid cancer (MTC), pheochromocytoma and a unique phenotype. The objectives of this study are to describe the rare M918V RET mutation discovered in 8 MTC kindreds from Brazil lacking the MEN 2B phenotype classically observed in M918T patients and to investigate the presence of a founder effect for this germline mutation. Eight apparently sporadic MTC cases were diagnosed with the germline M918V RET mutation.

High frequency of vitamin D receptor gene polymorphism FokI in Brazilian Type 1 diabetes mellitus patients with clinical autoimmune thyroid disease.

Background: Polymorphisms of vitamin D receptor (VDR) gene have been studied as genetic markers of type 1 diabetes mellitus (T1DM) and some studies have reported associations with autoimmune thyroid disease. The aim of this study was to evaluate the relationship between VDR FokI polymorphism (rs10735810), thyroid autoimmunity and thyroid dysfunction (TD) in Brazilian T1DM.

Methods: One-hundred-eighty T1DM patients were evaluated for age, duration of diabetes (DDM), positivity to TPO Antibody (TPOA), GAD Antibody (GADA), IA2 Antibody (IA2A) and fasting serum C-peptide (FCP) according to diagnosis of TD.

Macrocalcitonin Is a Novel Pitfall in the Routine of Serum Calcitonin Immunoassay.

Context: Calcitonin (CT) is a sensitive marker of medullary thyroid carcinoma (MTC) and is used for primary diagnosis and follow-up after thyroidectomy. However, persistently elevated CT is observed even after complete surgical removal without evidence of a recurrent or persistent tumor.

Objective: To investigate the presence of assay interference in the serum CT of MTC patients who are apparently without a structural disease.

Low iodine diet does not improve the efficacy of radioiodine for the treatment of Graves' disease.

Objective: Consuming a low-iodine diet (LID) is a widely accepted practice before administering radioiodine (131I) to evaluate and to treat thyroid disease. Although this procedure is well established for the management of patients with differentiated thyroid cancer, its use in patients with benign disease is unclear. So, we aimed to evaluate the influence of a LID on the outcome in patients with Graves' disease (GD) treated with 131I.

Assessment of the Effect of Two Distinct Restricted Iodine Diet Durations on Urinary Iodine Levels (Collected over 24 h or as a Single-Spot Urinary Sample) and Na(+)/I(-) Symporter Expression.

Introduction: A restricted iodine diet (RID) may be recommended for depletion of the whole-body iodine pool in patients with differentiated thyroid cancer referred for radioiodine treatment or a whole-body scan. Evaluation of the iodine pool is possible through urinary iodide (UI) measurements, which can be collected in 24-hour (24U) or spot urinary (sU) samples. However, the minimum period required for an RID to lower the iodine pool, the measurement of iodine in sU samples as a iodine pool marker, and the influence of the iodine pool on Na(+)/I(-) symporter (NIS) expression are debatable in the literature.

Adult exposure to bisphenol A (BPA) in Wistar rats reduces sperm quality with disruption of the hypothalamic-pituitary-testicular axis.

Reproductive physiology involves complex biological processes that can be disrupted by exposure to environmental contaminants. The effects of bisphenol A (BPA) on spermatogenesis and sperm quality is still unclear. The objective of this study was to investigate the reproductive toxicity of BPA at dosages considered to be safe (5 or 25mg BPA/kg/day).

Development and application of a novel sensitive immunometric assay for calcitonin in a large cohort of patients with medullary and differentiated thyroid cancer, thyroid nodules, and autoimmune thyroid diseases.

Background: Serum calcitonin (sCT) is a useful biomarker for medullary thyroid cancer (MTC). Consensus has not been reached concerning sCT measurements in the evaluation of nodular thyroid disease (NTD).

Objective And Methods: We developed a new immunofluorometric assay for sCT and have validated it in samples from 794 patients [203 with MTC, 205 with autoimmune thyroid disease (ATD), 248 with NTD, 80 with differentiated thyroid cancer (DTC) 'free of disease', 58 with chronic renal failure (CRF)] and 178 normal individuals, including samples after pentagastrin tests and samples from the washout of 92 FNA procedures in patients with NTD or MTC.

Basal serum thyroglobulin measured by a second-generation assay is equivalent to stimulated thyroglobulin in identifying metastases in patients with differentiated thyroid cancer with low or intermediate risk of recurrence.

Background: Guidelines for the follow-up of differentiated thyroid cancer (DTC) recommend the measurement of TSH-stimulated thyroglobulin (s-Tg) instead of basal Tg on T4 therapy (b-Tg). However, these guidelines were established using first-generation Tg assays with a functional sensitivity (FS) of 0.5-1.

Daily exposure to silver nanoparticles during prepubertal development decreases adult sperm and reproductive parameters.

As silver nanoparticles (AgNPs) have antimicrobial properties and potentiate the activity of some antibiotics, they are broadly used in both medical and nonmedical applications. In this study, prepubertal male Wistar rats were orally treated with 15 or 30 µg/kg/day AgNPs from postnatal day 23 (PND23) to PND58 and sacrificed at PND102. The acrosome integrity, plasma membrane integrity, mitochondrial activity and morphological alterations of the sperm were analyzed.

A ten-year clinical update of a large RET p.Gly533Cys kindred with medullary thyroid carcinoma emphasizes the need for an individualized assessment of affected relatives.

Objective: Reviewing the clinical outcomes of a large kindred with a RET p.Gly533Cys mutation, 10 years after the first description of this kindred, has provided an important set of clinical data for healthcare decision-making.

Design And Patients: We identified 728 RET533 Brazilian relatives, spread out over 7 generations.

Development, characterization and clinical validation of new sensitive immunofluorometric assay for the measurement of serum thyroglobulin.

Objective: In the last decade, data published stressed the role of highly-sensitive thyroglobulin (Tg) assays in the follow-up of differentiated thyroid carcinoma (DTC) patients. The present study describes a new, highly-sensitive Tg assay, compares it with an available commercial assay, and validates it in the follow-up of DTC patients.

Subjects And Methods: The immunofluorometric high-sensitivity Tg assay is based on monoclonal and polyclonal antibodies produced at our laboratories.

Optimizing nucleic acid extraction from thyroid fine-needle aspiration cells in stained slides, formalin-fixed/paraffin-embedded tissues, and long-term stored blood samples.

Objective: Adequate isolation of nucleic acids from peripheral blood, fine-needle aspiration cells in stained slides, and fresh and formalin-fixed/paraffin-embedded tissues is crucial to ensure the success of molecular endocrinology techniques, especially when samples are stored for long periods, or when no other samples can be collected from patients who are lost to follow-up. Here, we evaluate several procedures to improve current methodologies for DNA (salting-out) and RNA isolation.

Materials And Methods: We used proteinase K treatment, heat shock, and other adaptations to increase the amount and quality of the material retrieved from the samples.

One month is sufficient for urinary iodine to return to its baseline value after the use of water-soluble iodinated contrast agents in post-thyroidectomy patients requiring radioiodine therapy.

Background: There is a concern regarding the use of iodinated contrast agents (ICA) for chest and neck computed tomography (CT) to localize metastatases in patients with differentiated thyroid cancer (DTC). This is because the iodine in ICA can compete with (131)I and interfere with subsequent whole scans or radioactive iodine treatment. The required period for patients to eliminate the excess iodine is not clear.

Parity is not related to autoimmune thyroid disease in a population-based study of Japanese-Brazilians.

Background: It has been suggested that the female preponderance for autoimmune thyroid disease might be associated with hormonal differences, abortion, and fetal microchimerism. Findings emerging from the few epidemiological studies on this matter, however, are controversial. In this study, we investigated the hypothesis whether parity, abortion, and the use of estrogens are associated with a higher risk for thyroid autoimmunity.

Development of a sensitive and specific quantitative reverse transcription-polymerase chain reaction assay for blood thyroglobulin messenger ribonucleic acid in the follow-up of patients with differentiated thyroid carcinoma.

Context: Serum thyroglobulin is a sensitive tumor marker in the follow-up of patients with differentiated thyroid carcinoma (DTC), but the presence of endogenous anti-thyroglobulin antibodies (TgAb) can interfere on its measurement. To prevent interference by TgAb, several investigators have tried to quantify blood mRNA Tg by real-time RT-PCR, but the results have been variable, not reporting a correlation between mRNA Tg and the presence of metastases.

Objective: The aim of the study was to evaluate the development of a sensitive and specific quantitative RT-PCR assay for blood mRNA Tg in the follow-up of patients with DTC.

Subclinical thyroid dysfunctions are independent risk factors for mortality in a 7.5-year follow-up: the Japanese-Brazilian thyroid study.

Objective: The currently available data concerning the influence of subclinical thyroid disease (STD) on morbidity and mortality are conflicting. Our objective was to investigate the relationships between STD and cardiometabolic profile and cardiovascular disease at baseline, as well as with all-cause and cardiovascular mortality in a 7.5-year follow-up.

HNF1A gene polymorphisms and cardiovascular risk factors in individuals with late-onset autosomal dominant diabetes: a cross-sectional study.

Background: Type 2 diabetes mellitus (T2DM) is a genetically heterogeneous disease, hepatocyte nuclear factor-1 homeobox A (HNF1A) single-nucleotide polymorphisms (SNPs) playing a minor role in its pathogenesis. HNF1A is a frequent cause of monogenic diabetes, albeit with early-onset. Some uncommon subgroups like late-onset autosomal dominant diabetes mellitus (LOADDM) may present peculiar inheritance patterns with a stronger familial component.

[Urinary iodine in patients with auto-immune thyroid disorders in Santo André, SP, is comparable to normal controls and has been steady for the last 10 years].

Objective: Evaluate whether the increase of iodine in the diet would be the triggering factor for auto-immune thyropathies in the city of Santo André, SP.

Methods: Urinary iodine was determined in samples isolated from 58 patients, divided in 4 Groups, and in 13 normal individuals (controls).

Results: Urinary Iodine: Group 1--hyperthyroidism = 203.

Prevalence of vitamin D receptor gene polymorphisms FokI and BsmI in Brazilian individuals with type 1 diabetes and their relation to beta-cell autoimmunity and to remaining beta-cell function.

The effect of the vitamin D receptor (VDR) gene polymorphisms on susceptibility to type 1 diabetes (T1DM) is heterogeneous. Genetic factors may also influence the residual beta-cell function. We studied the frequency of VDR FokI (rs10735810) and BsmI (rs154410) polymorphisms in T1DM and their relationship to beta-cell autoimmunity and residual beta-cell function.

Association of genetic variants in the adiponectin encoding gene (ADIPOQ) with type 2 diabetes in Japanese Brazilians.

Aim: The objective of this study is to assess the contribution of ADIPOQ variants to type 2 diabetes in Japanese Brazilians.

Methods: We genotyped 200 patients with diabetes mellitus (100 male and 100 female, aged 55.0 years [47.