Publications by authors named "Joao R M Martins"

The association of thyroid function with essential and non-essential amino acids is understudied, despite their common metabolic roles. Thus, our aim was to evaluate the association of thyroid function with the levels of branched-chain amino acids (BCAAs-leucine, isoleucine, and valine) and of alanine in the general population. We utilized data from the São Paulo research center of ELSA-Brasil, a longitudinal population-based cohort study.

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Purpose: This article aims to describe the presentation of Plummer disease and its evolution after radioiodine treatment and determine factors that may influence treatment efficacy.

Patients And Methods: The sample included retrospective medical records of 165 adult patients with toxic nodular goiter treated with radioiodine between 1997 and 2017, followed up at a single thyroid center.

Results: The efficacy of treatment with a single dose of radioiodine was higher than 90%.

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Objective: To analyze the effects of androgen therapy on the thyroarytenoid (TA) muscle, expression of androgen receptors (ARs) and hyaluronic acid (HA) concentration in the vocal folds (VFs) of adult female rats.

Methods: Twenty-one adult female Wistar rats were divided into experimental and control groups. The experimental group received weekly intramuscular injections of nandrolone decanoate for 9 weeks.

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Objective: The risk of malignancy and diagnostic accuracy of fine-needle aspiration biopsy (FNAB) of thyroid nodules (TN) with diameters ≥ 3-4 cm remains controversial. However, some groups have indicated surgical treatment in these patients regardless of the FNAB results. We aimed to evaluate the diagnostic accuracy of the FNAB in systematically resected ≥4 cm TN and if the risk of malignancy is higher in these patients.

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Thyroid cancer is the most common endocrine malignancy, and papillary thyroid carcinoma (PTC) is the main subtype. The cribriform morular variant is a histological phenotype of PTC characterized by its relationship with familial adenomatous polyposis (FAP). Description of the case: We report the genetic assessment of a 20-year-old female patient diagnosed with a cribriform-morular variant of PTC and FAP.

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: The disease caused by hepatitis C virus (HCV) is asymptomatic, silent, and progressive liver disease. In HCV-infected patients the increase in serum HA is associated with the development of hepatic fibrosis and disease progression. : HCV-RNA detection was performed in all serological samples of blood donors that tested positive using HCV Ultra ELISA.

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This position statement was prepared to guide endocrinologists on the best approach to managing thyroid disorders during the coronavirus disease (COVID-19) pandemic. The most frequent thyroid hormonal findings in patients with COVID-19, particularly in individuals with severe disease, are similar to those present in the non-thyroidal illness syndrome and require no intervention. Subacute thyroiditis has also been reported during COVID-19 infection.

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Objectives: Restless legs syndrome (RLS) is a frequent comorbid condition associated with distinct unrelated diseases. While the incidence of RLS has not been definitively confirmed, RLS-like symptoms have been reported in a section of Asian population who also had hyperthyroidism. The prevalence of RLS is generally low in Asian populations.

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Multiple endocrine neoplasia type 2 (MEN2) is an autosomal dominant genetic disease caused by RET gene germline mutations that is characterized by medullary thyroid carcinoma (MTC) associated with other endocrine tumors. Several reports have demonstrated that the RET mutation profile may vary according to the geographical area. In this study, we collected clinical and molecular data from 554 patients with surgically confirmed MTC from 176 families with MEN2 in 18 different Brazilian centers to compare the type and prevalence of RET mutations with those from other countries.

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Objective: Initial diagnosis of medullary thyroid carcinoma (MTC) is frequently associated with advanced stages and a poor prognosis. Thus, the need for earlier diagnoses and detection in relatives at risk for the disease has led to increased use of RET genetic screening.

Subjects And Methods: We performed RET screening in 247 subjects who were referred to the Brazilian Research Consortium for Multiple Endocrine Neoplasia (BRASMEN) Center in the State of Ceará.

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Purpose: The present study evaluates chondroitin sulfate (CS) and heparan sulfate (HS) in the urine and hyaluronic acid (HA) in the plasma of patients with prostate cancer before and after treatment compared to a control group.

Materials And Methods: Plasma samples were used for HA dosage and urine for quantification of CS and HS from forty-four cancer patients and fourteen controls. Clinical, laboratory and radiological information were correlated with glycosaminoglycan quantification by statistical analysis.

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Aim: Resistance to thyroid hormone (RTH), characterized by persistent hyperthyroxinemia with non-suppressed thyrotropin (TSH), is mostly caused by mutations in thyroid hormone receptor beta gene (THRB). Two differential diagnoses should be considered due to similar clinical and laboratory findings: TSH-producing pituitary adenoma (TPA) and Familial Dysalbuminemic Hyperthyroxinemia (FDH). The aim of this study is to describe our single tertiary center experience in the molecular diagnosis of RTH in Brazilian patients, analyzing their clinical and laboratory characteristics and the most common differential diagnosis.

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Matrix proteoglycans (PGs) have shown promise as biomarker in malignancies. We employed agarose gel eletrophoresis, quantitative real- time reverse transcription-polymerase chain reaction and immunohistochemistry to evaluate the content of sulfated glicosaminoglycans (chondroitin sulfate and heparan sulfate) and expression of PG (biglycan, glypican, perlecan, syndecan e versican) in patient-matched normal and tumor tissues obtained from resected specimens of lung cancer. A significant increase of heparan sulfate (HS) and chondroitin sulfate (CS) concentrations was found in tumor tissue samples when compared to normal lung tissue samples.

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Background: - Periportal fibrosis is the major pathological consequence of the Schistosoma mansoni infection.

Objective: - To evaluate the accuracy of serum markers and to construct an index to assess fibrosis.

Methods: - Patients (n=116) with schistosomiasis were evaluated by ultrasound scan and measurements of serum levels of aminotransferases, γ-glutamyl transferase, alkaline phosphatase, hyaluronic acid, cytokines and platelets.

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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.

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Introduction: The distribution, concentration and function of glycosaminoglycans in the various vocal fold tissues are still unclear.

Objective: To evaluate the distribution and concentration of sulfated glycosaminoglycans in different layers of the human vocal fold according to gender and age.

Methods: We used 11 vocal folds obtained from cadavers (7 men and 4 women) with no laryngeal lesion, less than 12h after death, and aged between 35 and 98 years.

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Thyroglobulin (Tg) is the major glycoprotein produced by the thyroid gland, where it serves as a template for thyroid hormone synthesis and as an intraglandular store of iodine. Measurement of Tg levels in serum is of great practical importance in the follow-up of differentiated thyroid carcinoma (DTC), a setting in which elevated levels after total thyroidectomy are indicative of residual or recurrent disease. The most recent methods for serum Tg measurement are monoclonal antibody-based and are highly sensitive.

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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.

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Introduction: The search for a specific marker that could help to distinguish between differentiated thyroid carcinoma and benign lesions remains elusive in clinical practice. Heparanase (HPSE) is an endo-beta-glucoronidase implicated in the process of tumor invasion, and the heparanase-2 (HPSE2) modulates HPSE activity. The aim of this study was to evaluate the role of heparanases in the development and differential diagnosis of follicular pattern thyroid lesions.

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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.

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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.

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