Publications by authors named "Meyer Knobel"

Patients with large benign goiters often present local compressive symptoms that require surgical treatment, including dysphagia, neck tightness, and airway obstruction. In contrast, patients with such goiters who remain asymptomatic may be observed after exclusion of malignancy. The use of levothyroxine (LT4) to reduce the volume of the goiter is still a controversial treatment for large goiters, and the optimal surgical procedure for multinodular goiter is still debatable.

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Chronic autoimmune thyroiditis (CAT) is the most common cause of acquired hypothyroidism, which requires lifelong levothyroxine replacement therapy. Currently, no effective therapy is available for CAT. Thus, the objective of this study was to evaluate the efficacy of low-level laser therapy (LLLT) in patients with CAT-induced hypothyroidism by testing thyroid function, thyroid peroxidase antibodies (TPOAb), thyroglobulin antibodies (TgAb), and ultrasonographic echogenicity.

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The aim of this study was to identify the genetic defect of a patient with dyshormonogenetic congenital hypothyroidisms (CH) with total iodide organification defect (TIOD). A male child diagnosed with CH during neonatal screening. Laboratory tests confirmed the permanent and severe CH with TIOD (99% perchlorate release).

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Background: Treatment of multinodular goiters (MNGs) is highly controversial. Radioiodine (RAI) therapy is a nonsurgical alternative for the elderly who decline surgery. Recently, recombinant human thyrotropin (rhTSH) has been used to augment RAI uptake and distribution.

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High nutritional levels of iodine may induce a higher prevalence of autoimmune thyroiditis, hypothyroidism, goiter, as well as hyperthyroidism, mostly in the elderly. This study assessed thyroid volume and ultrasonographic abnormalities as well as urinary iodine excretion (UIE) in 964 schoolchildren living in an iodine-sufficient area in southern Brazil. Thyroid volume correlated with age and body surface area in boys and girls.

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Context: Thyroglobulin (TG) is a large glycoprotein and functions as a matrix for thyroid hormone synthesis. TG gene mutations give rise to goitrous congenital hypothyroidism (CH) with considerable phenotype variation.

Objectives: The aim of the study was to report the genetic screening of 15 patients with CH due to TG gene mutations and to perform functional analysis of the p.

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Objectives: To evaluate the prevalence of thyroid dysfunction in elderly cardiac patients in an outpatient setting.

Subjects And Methods: A total of 399 consecutive patients (268 women, age range 60-92 years) who were followed at Heart Institute were evaluated for thyroid dysfunction with serum free T4, TSH, anti-Peroxidase antibodies, urinary iodine excretion measurements and thyroid ultrasound.

Results: Hyperthyroidism (overt and subclinical) was present in 29 patients (6.

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Objective: To extend the molecular analysis of the IVS30+1G>T intronic thyroglobulin (TG) mutation, and to report the eleven year follow-up of the affected patients. METHOSD: Two siblings with severe congenital hypothyroidism with fetal and neonatal goiter, harboring the IVS30+1G>T mutation were included. Nodular and non-nodular thyroid tissue specimens were collected.

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Background: Thyroglobulin (Tg) is a large glycoprotein that is intimately involved in the biosynthesis of thyroxine and triiodothyronine. At least 38 mutations have been described in the Tg gene that are associated with varying degrees of hypothyroidism. We studied the Tg gene in four related subjects with congenital hypothyroidism.

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Context: The expression of sodium iodide symporter (NIS) is required for iodide uptake in thyroid cells. Benign and malignant thyroid tumors have low iodide uptake. However, previous studies by RT-PCR or immunohistochemistry have shown divergent results of NIS expression in these nodules.

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Objective: To evaluate the prevalence of chronic autoimmune thyroiditis (CAT) and iodine-induced hypothyroidism, hyperthyroidism (overt and subclinical), and goiter in a population exposed to excessive iodine intake for 5 years (table salt iodine concentrations: 40-100 mg/kg salt). Design This was a population-based, cross-sectional study with 1085 participants randomly selected from a metropolitan area in São Paulo, Brazil, and conducted during the first semester of 2004.

Methods: Thyroid ultrasound examination was performed in all participants and samples of urine and blood were collected from each subject.

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Context: Mesotherapy consists of cutaneous injections of a mixture of compounds and has recently been used for cosmetic purposes to reduce local fat and cellulite. To date, several reports have described only local adverse events related to this therapy. We describe the first report of a female patient who developed thyrotoxicosis due to cosmetic mesotherapy with triiodothyroacetic acid in its formulation.

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Radioiodine ((131)I) treatment for nontoxic and toxic multinodular goiter (MNG) is an alternative therapeutic procedure used especially for patients with contraindication for surgery. Several studies have been conducted in recent years assessing the use of recombinant human TSH (rhTSH) in increasing (131)I uptake in MNGs. This procedure also decreases the activity level of the administered (131)I, changes the distribution of (131)I in the thyroid, lowers the absorption dose, and dramatically reduces the volume of the goiter (50-75% of the baseline volume).

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Treatment of large multinodular goiter (MNG) with radioiodine preceded by recombinant human thyrotropin (0.1 mg rhTSH) has been shown to be a safe alternative for patients with comorbidities that preclude surgery. However, the increase in serum thyroid hormones that follows both treatments may be harmful for some patients, particularly those with underlying cardiovascular disease.

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Unlabelled: Iodine is a trace element that is essential for the synthesis of thyroid hormone. Both chronic iodine deficiency and iodine excess have been associated with hypertrophy and hyperplasia of follicular cells, attributed to excessive secretion of TSH. This may be associated to thyroid cancer risk, particularly in women.

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Purpose: To evaluate the preoperative assessment of thyroid nodules using ultrasound studies and cytology of nodular aspirates.

Subjects And Methods: 2,468 patients with thyroid nodules were examined from 1999 to 2005. All patients were clinically examined and underwent ultrasonography followed by fine-needle aspiration biopsy (FNAB) and cytology.

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Purpose: To evaluate the prevalence of chronic autoimmune thyroiditis in 2 urban areas of metropolitan São Paulo (Brazil): Polo Area neighboring a large petrochemical complex and São Bernardo Campo Area (control area).

Subjects And Methods: Subjects were randomly included from the adult population (20 to 70 years of age) of both genders (women 80%, men 20%) who voluntarily agreed to participate. From the Polo Area, in the vicinity of a large petrochemical industrial complex, 409 subjects were included; from the control area (São Bernardo Campo Area) 420 individuals were included.

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The aim of the present study was to evaluate a new proposal for increasing compliance to the clinical management of patients with Graves' disease (GD) in a large and public University Hospital. The patients were carefully selected (no previous GD treatment, goiter volume less than 6 mL must be living in the metro area of São Paulo), received medication at no cost, were contacted frequently by the social worker and alerted for the date of consultation and only referred to a single endocrinologist during all phases of treatment. We recruited 229 patients with GD that were initially treated with methimazole (MMI--60 mg q.

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Radioiodine (RAI) treatment has increasingly been used mostly in elderly patients with multinodular goiter (MNG) as an alternative for surgery. Recombinant human thyrotropin (rhTSH) has been demonstrated to increase the uptake of RAI and also to promote a more even distribution of radionuclide among the various nodules. We have compared the surge of autoantibodies to thyroid peroxidase (anti-TPO) and to the TSH receptor (TRAb) in two groups of patients with MNG.

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The thyroid gland promotes its adaptation to iodine deficiency inducing an increase in the iodine uptake followed by a substantial increase in the thyroid gland mass (goiter). Simultaneously, there is a preferential T3 secretion by the follicular cell and a persistently elevated serum TSH. Laboratory tests, isotopic methods and imaging are routinely used to verify the altered thyroid pathophysiology.

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The detection of autoantibodies to the thyrotropin-receptor antibody (TRAb) is commonly used in clinical practice for the diagnostic assessment of Graves' disease (GD) and its differential diagnosis from toxic multinodular goiter (MNG) and autonomous adenoma. Additionally, TRAb assays can be useful during antithyroid drug treatment of GD to evaluate the risk of relapse and/or remission. The detection of TRAb was originally performed using a radioreceptor assay based on detergent-solubilized porcine thyroid membranes (TRAb).

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Mutations of the thyroperoxidase (TPO) gene have been reported as being the most severe and frequent abnormality in thyroid iodide organification defect (IOD) causing goitrous congenital hypothyroidism. The objective of this study was to screen and subsequently identify TPO gene mutations in patients with congenital hypothyroidism with evidence of total iodine organification defects (TIOD) or partial iodine organification defect (PIOD) as defined by the perchlorate discharge test. Seven goitrous patients with TIOD and seven patients with PIOD, from three and five unrelated families, respectively, were studied.

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