Hashimoto's thyroiditis - an independent risk factor for papillary carcinoma / Hashimoto's thyroiditis - an independent risk factor for papillary carcinoma

Abstract Introduction: The link between Hashimoto's thyroiditis and thyroid carcinoma has long been a topic of controversy. Objective: The aim of our study was to determine the prevalence of thyroid carcinoma and Hashimoto's thyroiditis coexistence in histopathologic material of thyroidectomized patients. Methods: In a retrospective study, the clinicohistopathologic data of 2117 patients (1738 females/379 males), who underwent total or partial thyroidectomy for thyroid gland disorder at a single institution from the 1st of January 2005 to the 31st of December 2014 were analyzed. Results: Thyroid carcinoma was detected in 318 cases (15%) and microcarcinoma (thyroid cancer ≤10 mm in diameter) was found in permanent sections in 169 cases (8%). Hashimoto's thyroiditis was detected in 318 (15%) patients. Hashimoto's thyroiditis was significantly more often associated with thyroid carcinoma and microcarcinoma compare to benign condition (p = 0.048, p = 0.00014, respectively). Coexistence of Hashimoto's thyroiditis and thyroid carcinoma/thyroid microcarcinoma did not affect tumor size (p = 0.251, p = 0.098, respectively), or tumor multifocality (p = 0.831, p = 0.957, respectively). Bilateral thyroid microcarcinoma was significantly more often detected when Hashimoto's thyroiditis was also diagnosed (p = 0.041), but presence of Hashimoto's thyroiditis did not affect bilateral occurrence of thyroid carcinoma (p = 0.731). Conclusion: Hashimoto's thyroiditis is associated with significantly increased risk of developing thyroid carcinoma, especially thyroid microcarcinoma.

Resumo: Introdução: A relação entre a tireoidite de Hashimoto e o carcinoma de tireoide tem sido um tema de controvérsia por um longo tempo. Objetivo: Determinar a prevalência da coexistência de carcinoma de tireoide e tireoidite de Hashimoto no exame histopatológico de amostras de pacientes tireoidectomizados. Método: Em um estudo retrospectivo, foram analisados os dados clinico-histopatológicos de 2.117 pacientes (1.738 mulheres/379 homens), submetidos à tireoidectomia total ou parcial por distúrbio da glândula tireoide em uma única instituição, de 1º de janeiro de 2005 a 31 de dezembro de 2014. Resultados: O carcinoma de tireoide foi detectado em 318 casos (15%) e o microcarcinoma (câncer de tireoide ≤ 10 mm de diâmetro) foi encontrado em secções permanentes em 169 casos (8%). A tireoidite de Hashimoto foi detectada em 318 (15%) pacientes e foi associada ao carcinoma da tireoide e ao microcarcinoma com maior frequência em comparação com condições benignas (p = 0,048, p = 0,00014, respectivamente). A coexistência de tireoidite de Hashimoto e carcinoma/microcarcinoma não influenciou o tamanho do tumor (p = 0,251, p = 0,098, respectivamente) ou a multifocalidade tumoral (p = 0,831, p = 0,957, respectivamente). O microcarcinoma de tireoide bilateral foi detectado com maior frequência quando a tireoidite de Hashimoto também foi diagnosticada (p = 0,041), mas a presença de tireoidite não influenciou na ocorrência bilateral de carcinoma (p = 0,731). Conclusão: A tireoidite de Hashimoto está associada a um aumento significativo do risco do desenvolvimento de carcinoma de tireoide, especialmente microcarcinoma da tireoide.

Effects of magnesium on cytomorphology and enzyme activities in thyroid of rats.

Till date knowledge regarding the effects of high dietary magnesium on thyroid gland is incomprehensive though certain epidemiological studies reported development of thyroid gland dysfunctions in people with chronic exposure to hard water (especially with high magnesium) despite sufficient iodine consumption. The present study is to explore the effects of chronic high dietary magnesium exposure on thyroid morphology and functional status. Male adult albino Wistar strain rats were treated with graded doses of magnesium sulphate (MgSO4; 0.5, 1.0 and 1.5 g %) for 60 days and changes in different thyroid parameters were investigated. Significantly stimulated thyroid peroxidase and Na+–K+-ATPase and altered idothyronine 5/- deiodinase type I activities, enhanced serum thyroxine (T4) (both total and free), total triiodothyronine (T3) and thyroid stimulating hormone with decreased free T3 levels and T3/T4 ratio (T3:T4) along with enlargement of thyroid with associated histopathological changes were observed in the treated groups. The results clearly confirm that chronic high dietary magnesium exposure causes potential thyroid disruption as reported in earlier epidemiological studies.

B-RafV600E inhibits sodium iodide symporter expression via regulation of DNA methyltransferase 1

B-RafV600E mutant is found in 40-70% of papillary thyroid carcinoma (PTC) and has an important role in the pathogenesis of PTC. The sodium iodide symporter (NIS) is an integral plasma membrane glycoprotein that mediates active iodide transport into the thyroid follicular cells, and B-RafV600E has been known to be associated with the loss of NIS expression. In this study, we found that B-RafV600E inhibited NIS expression by the upregulation of its promoter methylation, and that specific regions of CpG islands of NIS promoter in B-RafV600E harboring PTC were highly methylated compared with surrounding normal tissue. Although DNA methyltransferase 3a and 3b (DNMT3a,3b) were not increased by B-RafV600E, DNMT1 expression was markedly upregulated in PTC and B-RafV600E expressing thyrocytes. Furthermore, DNMT1 expression was upregulated by B-RafV600E induced NF-kappaB activation. These results led us to conclude that NIS promoter methylation, which was induced by B-RafV600E, is one of the possible mechanisms involved in NIS downregulation in PTC.

Alterações da PET-FDG na avaliação pré-operatória de pacientes com nódulos tireoidianos e correlação com marcadores imuno-histoquímicos / FDG PET abnormalities in preoperative evaluation of patients with thyroid nodules and association with immunohistochemical biomarkers

INTRODUÇÃO: Cerca de 80% dos nódulos de tireóide com citologia indeterminada são benignos. É possível que a tomografia por emissão de pósitrons (PET) com 2-[18F]- fluoro-2-desoxi-D-glicose (FDG) ajude a identificar quais dessas lesões são malignas. A captação de FDG depende da expressão de GLUTs (transportadores de glicose transmembrana) e hexoquinases. Captação difusa de FDG no leito tireoidiano tem ainda sido associada à tireoidite autoimune crônica (TAC), embora haja evidências de que pacientes com parênquima tireoidiano aparentemente sadio possam ter essa alteração. OBJETIVOS: (1) Determinar a sensibilidade e especificidade da PET-FDG no diagnóstico pré-operatório de malignidade dos nódulos tireoidianos, especialmente daqueles com resultados citológicos indeterminados, e avaliar esse desempenho no subgrupo de pacientes com TAC. (2) Determinar a correlação entre o achado de captação difusa tireoidiana da FDG à PET com o diagnóstico histopatológico de TAC e compará-la às concentrações plasmáticas dos anticorpos antitireoidianos. (3) Determinar a correlação entre a expressão dos marcadores imuno-histoquímicos GLUT 1, GLUT 3, GLUT 12, hexoquinase 2 e hexoquinase 3 com o diagnóstico histopatológico dos nódulos e com a captação de FDG apresentada pelos mesmos. MÉTODOS: 56 pacientes com nódulo de tireóide (42 com citologia indeterminada, 10 compatíveis com carcinoma papilífero e 4 com citologia benigna) realizaram PET-FDG e foram submetidos à tireoidectomia. Os resultados da PET-FDG foram comparados com o diagnóstico histopatológico do nódulo, com o infiltrado linfocitário no parênquima tireoidiano, com o diagnóstico de TAC e com os resultados do estudo imuno-histoquímico de micromatriz tecidual de tecido correspondente ao nódulo tireoidiano puncionado e ao tecido tireoidiano não nodular. RESULTADOS: 1) Todos os 21 pacientes com câncer de tireóide (11 com citologia indeterminada) apresentaram captação focal de FDG na tireóide...

INTRODUCTION: Around 80% of thyroid nodules with indeterminate cytological result are benign. Positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy- D-glucose (FDG) might help to identify malignant thyroid lesions. FDG uptake depends on GLUTs expression (transmembranous glucose transporters) and on hexokinases. Although diffuse FDG thyroid uptake has been associated with chronic autoimmune thyroiditis (CAT), there is some evidence that patients with apparently normal thyroid parenchyma can display this pattern of FDG uptake. OBJECTIVES: (1) To assess the sensitivity and specificity of FDG PET in identifying thyroid malignancy in the preoperative evaluation of thyroid nodules and evaluate these results in the subgroup of patients with indeterminate cytological results and in the subgroup with CAT. (2) To compare the finding of diffuse FDG thyroid uptake with the histopathologic diagnosis of CAT and with the serum levels of antithyroid antibodies. (3) To evaluate the immunoexpression by thyroid nodules of GLUT 1, GLUT 3, GLUT 12, hexokinase 2 and hexokinase 3 and to compare it with the histopathologic diagnosis of these nodules and with FDG uptake. METHODS: 56 patients with thyroid nodules (42 with indeterminate cytological result, 10 with papillary carcinoma and 4 with benign cytological result) underwent FDG PET and, subsequently, thyroidectomy. FDG PET results were compared with the histopathologic diagnosis of the nodule, lymphocytic infiltrate of thyroid parenchyma, CAT diagnosis and immunohistochemical results of tissue microarray of the tissue from the thyroid nodule and the normal thyroid parenchyma...

Apoptose, proliferação e histomorfometria do baço de ratas adultas com hipofunção tireoidiana e ovariana / Apoptosis, proliferation and spleen histomorphometry of adult female rats with thyroid and ovarian hypofunction

Apoptose, proliferação e histomorfometria do baço foram investigados em ratas Wistar adultas ovariectomizadas e não-ovariectomizadas, mantidas em hipotireoidismo induzido pela administração diária de propiltiouracil (PTU) por 120 dias. Dois grupos eutireóideos ovariectomizados e não-ovariectomizados serviram como controle. Foi colhido o plasma para dosagem de T4 livre e o baço para análise da histomorfometria, do índice apoptótico e da expressão imunohistoquímica de caspase 3 e CDC47. Valores de T4 livre foram menores nas ratas tratadas com PTU (p < 0,05). Nos grupos hipotireóideos houve redução do peso do baço, do número e do tamanho dos folículos linfóides e aumento do índice apoptótico e da expressão de caspase 3 (p < 0,05). Porém, o baço de ratas hipotireóideas ovariectomizadas apresentou aumento menos acentuado do índice apoptótico e da expressão de caspase 3 do que o baço de ratas hipotireóideas não-ovariectomizadas (p < 0,05). O grupo eutireóideo ovariectomizado apresentou hiperplasia da polpa branca em relação ao grupo eutireóideo não-ovariectomizado. Não houve diferença na expressão de CDC47 entre os grupos. Conclui-se que a hipofunção tireoidiana e gonadal apresentam efeitos distintos no baço e que na associação hipotireoidismo-hipogonadismo há aumento menos acentuado do índice apoptótico e da expressão de caspase-3 esplênica do que no hipotireoidismo isolado.

Apoptosis, proliferation and histomorphometry of spleen were investigated in ovariectomized and non-ovariectomized adult Wistar rats maintained in hypothyroidism induced by daily administration of propylthiouracil (PTU) during 120 days. Two groups ovariectomized euthyroid and non-ovariectomized euthyroid were used as controls. Plasma was collected for free T4 dosage and the spleen for histomorphometry analysis, apoptosis index and the immunohistochemistry expression of caspase 3 and CDC47. Values of free T4 were lower in rats treated with PTU (p<0.05). In the hypothyroid groups there was some decrease in the spleen weight as well as the number and size of lymphoid follicles and there was some increase in the apoptotic index and the caspase 3 expression (p<0.05). However, the increase in the apoptosis index and the expression of caspase 3 in ovariectomized hypothyroid rats spleen was less accentuated than non-ovariectomized hypothyroid ones (p<0.05). The ovariectomized euthyroid group presented white pulp hyperplasia in comparison to the non-ovariectomized euthyroid group. There was no difference in the CDC47 expression between groups. It was concluded that the thyroid and ovarian hypofunction have distinct effects on the spleen and that in the hypothyroidism-hypogonadism association, the increase in the apoptosis index and in the expression of splenic caspase 3 is not as much as in isolated hypothyroidism.

Regulation of Inhibitors of Differentiation Family Proteins by Thyroid-Stimulating Hormone in FRTL-5 Thyroid Cells

Members of the inhibitors of differentiation (Id) family of helix-loop-helix (HLH) proteins are known to play important roles in the proliferation and differentiation of many cell types. Thyroid-stimulating hormone (TSH) regulates proliferation and differentiation by activating TSH receptor (TSHR) in thyrocytes. In this study, we found that Id2, one of the Id family proteins, is a major target for regulation by TSH in FRTL-5 thyroid cells. TSH rapidly increases the Id2 mRNA level in FRTL-5 thyroid cells but the Id2 protein showed biphasic regulatory patterns, being transiently reduced and subsequently induced by TSH treatment. Transient reduction of Id2 protein was noted within 2 hr of TSH treatment and was mediated by proteasomal degradation. Moreover, reduced Id2 expression correlated with the activity of the phosphatidylinositol 3 kinase pathway, which is activated by TSH. Although TSH increases the activity of the Id2 promoter, TSH-induced activation of this promoter was independent of c-Myc. Id2 did not alter TTF-1- and Pax-8-mediated effects on the regulation of the Tg promoter. Thus, in summary, we found that TSH regulates Id2 expression, but that Id2 does not alter the expression of thyroid-specific genes, such as Tg, in FRTL-5 thyroid cells.

Citología tiroidea: métodos complementarios / Thyroid cytology: complementary methods

Describir nuestra experiencia en la punción aspiración con aguja fina de tiroides utilizando ultrasonido tiroideo y/o control citológico inmediato para así evaluar la sensibilidad de los mismos en apoyo a este procedimiento. Se revisaron historias clínicas de 242 pacientes entre enero 2005 y abril 2007 en los cuales se realizaron 130 punciones guiadas por ultrasonido, 126 con control citológico inmediato y ambos en 26 pacientes; evaluando el número, tamaño y distribución de los nódulos, caraterísticas ecográficas, número de láminas, diagnóstico citológico y correlación con el diagnóstico definitivo. Se encontró mayor prevalencia de nódulos únicos entre 1 y 4 cm; ubicándose principalmente en el lóbulo derecho siendo más frecuentes las lesiones complejas. Para valorar los diagnósticos citológicos, fueron agrupados como maligno, hipercelular o hipocelular, consiguiendo porcentajes de 12 por ciento, 81 por ciento respectivamente. De las muestras hipocelulares 15 fueron guiadas por ultrasonido y 5 con control citológico inmediatos, en 3 casos se utilizaron ambos métodos. La sensibilidad de las punciones guiadas por ultrasonido fue de 88 por ciento y de los casos en los que se utilizó control citológico inmediato del 96 por ciento. El 20 por ciento de los pacientes fueron llevados a cirugía, siendo compatible el diagnóstico citológico con el definitivo en 88 por ciento de los mismos. La punción aspiración con aguja fina de tiroides es un método adecuado para suministrar información de los nódulos tiroideos, cuya sensibilidad aumenta al utilizar soporte citológico y ultrasonográfico. Estudios posteriores deben realizarse con el objetivo de valorar la relación costo beneficio en cada caso.

Biphasic modulation of insulin receptor substrate-1 during goitrogenesis

Insulin receptor substrate-1 (IRS-1) is the main intracellular substrate for both insulin and insulin-like growth factor I (IGF-I) receptors and is critical for cell mitogenesis. Thyrotropin is able to induce thyroid cell proliferation through the cyclic AMP intracellular cascade; however, the presence of either insulin or IGF-I is required for the mitogenic effect of thyroid-stimulating hormone (TSH) to occur. The aim of the present study was to determine whether thyroid IRS-1 content is modulated by TSH in vivo. Strikingly, hypothyroid goitrous rats, which have chronically high serum TSH levels (control, C = 2.31 ± 0.28; methimazole (MMI) 21d = 51.02 ± 6.02 ng/mL, N = 12 rats), when treated with 0.03 percent MMI in drinking water for 21 days, showed significantly reduced thyroid IRS-1 mRNA content. Since goiter was already established in these animals by MMI for 21 days, we also evaluated IRS-1 expression during goitrogenesis. Animals treated with MMI for different periods of time showed a progressive increase in thyroid weight (C = 22.18 ± 1.21; MMI 5d = 32.83 ± 1.48; MMI 7d = 31.1 ± 3.25; MMI 10d = 33.8 ± 1.25; MMI 14d = 45.5 ± 2.56; MMI 18d = 53.0 ± 3.01; MMI 21d = 61.9 ± 3.92 mg, N = 9-15 animals per group) and serum TSH levels (C = 1.57 ± 0.2; MMI 5d = 9.95 ± 0.74; MMI 7d = 10.38 ± 0.84; MMI 10d = 17.72 ± 1.47; MMI 14d = 25.65 ± 1.23; MMI 18d = 35.38 ± 3.69; MMI 21d = 31.3 ± 2.7 ng/mL, N = 9-15 animals per group). Thyroid IRS-1 mRNA expression increased progressively during goitrogenesis, being significantly higher by the 14th day of MMI treatment, and then started to decline, reaching the lowest values by the 21st day, when a significant reduction was detected. In the liver of these animals, however, a significant decrease of IRS-1 mRNA was detected after 14 days of MMI treatment, a mechanism probably involved in the insulin resistance that occurs in hypothyroidism. The increase in IRS-1 expression during goitrogenesis may represent...

Effect of conjugated equine estrogens and tamoxifen administration on thyroid gland histomorphology of the rat

OBJETIVO: Avaliar a ação dos estrogênios conjugados eqüinos e do tamoxifeno na histomorfologia da tireóide de ratas. MÉTODO: Estrogênios conjugados eqüinos são ministrados clinicamente como terapia estrogênica e contêm formulação complexa com muitos tipos de estrogênios que diminuem os sintomas da pós-menopausa. Trinta ratas adultas ooforectomizadas foram divididas aleatoriamente em três grupos: GI – veículo (propilenoglicol); GII - ECE 200 µg/Kg por dia; e GIII – TAM 1 mg/Kg por dia. Acrescentou-se ainda um grupo de 10 animais com os ovários intactos e tratados com veículo (GIV). Todos os animais foram tratados por gavagem durante 50 dias consecutivos, ao final foram coletadas amostras do sangue e a tireóide removida e processada para análise morfológica e imunohistoquímico para avaliar o PCNA. RESULTADOS: A maior altura das células foliculares foi observada nos animais tratados com ECE (14,90 ± 0,20 µm), TAM (14,90 ± 0,10 µm) e no grupo com ovários intactos (15,10 ± 0,50 µm), comparando-se aos controles ovariectomizados (GI) (9,90 ± 0,20 µm) (p<0,001). A maior área folicular foi detectada nos grupos tratados com ECE (2.225 ± 51 µm2) e com TAM (2.127 ± 67 µm2), comparado ao veículo (5.016 ± 53 µm2) em animais ooforectomizados. Os níveis de T4 e T3 nos grupos tratados com ECE, com TAM e no grupo com ovários intactos foram maiores do que no grupo tratado com veículo (p<0,001). O índice do PCNA no grupo tratado com veículo foi menor do que em todos os outros grupos. CONCLUSÃO: Nossos dados sugerem que a administração de ECE e TAM resulta em atividade proliferativa na tireóide.

Diagnostic specificity of fine needle aspiration cytology [FNAC] in cold thyroid nodule and its surgical management

To determine the diagnostic potential and cost-effectiveness of various diagnostic methods and effectiveness of various treatment methods for the management of cold thyroid nodules Prospective surgical study with follow up. Surgical outdoor and surgical unit-iv Nishtar Hospital Multan. Random selection of 30 patients of cold thyroid nodule regardless of age, sex and domicile. Of the 30 patients on FNAC 5 patients [16.66%] had cystic nodules, 18 patients [60%] had benign solid nodules. 2 patients [6.66%] had malignant disease while 5 patients [16 66%] had cytology Indeterminate or suspicious for malignancy Out of 5 patients with cystic nodules, who were aspirated-2 patients [40%] had no recurrence while 2 patients who had blood stained aspirate had lobectomy. 5 patients out of 18 [27,77%] were given LT4 therapy. 2 patients out of these 5 [40%] had more than 50% decrease in the size of the nodule while 1 patient had no benefit. 2 patients did not continue the medical treatment and opted for surgery. The fine needle aspiration cytology proved to be a reliable method for the preoperative diagnosis of cold thyroid nodule and better planning of their management Routine use of USG and thyroid scan was not helpful to distinguish between benign and malignant cold nodules. A need was felt about the selective policy for the surgical excision of cold throid nodule

Punção aspirativa por agulha fina guiada por ultra-sonografia de nódulos tireoidianos: estudo de 63 casos / Ultrasound-guided fine needle aspiration biopsy of thyroid nodules: study of 63 cases

Neste trabalho foi revisada a técnica empregada na execução da punção aspirativa por agulha fina guiada por ultra-sonografia, e são descritos os seus benefícios no diagnóstico de nódulos tireoidianos. Foram realizadas punções aspirativas por agulha fina em 63 pacientes do Hospital Universitário Clementino Fraga Filho da Universidade Federal do Rio de Janeiro, encaminhados ao Serviço de Radiodiagnóstico, no período de agosto de 2001 a junho de 2002. Dos 63 pacientes estudados, 58 (92 por cento) eram do sexo feminino e cinco (8 por cento) eram do sexo masculino, com uma relação mulher/homem de cerca de 11:1. Trinta e um pacientes (49 por cento) se situaram na quinta e sexta décadas de vida. Oitenta e nove por cento dos pacientes apresentaram-se com nódulos múltiplos ao exame ecográfico; apenas 11 por cento dos pacientes tinham nódulo único. Em relação aos laudos citológicos dos nódulos puncionados, 47 por cento foram benignos, 31 por cento, suspeitos, 17 por cento, inadequados e apenas 5 por cento, malignos. Todos os nódulos malignos (três pacientes) tiveram o diagnóstico citológico de carcinoma papilífero. Dos nódulos benignos, 93 por cento foram diagnosticados como hiperplasia nodular e apenas 7 por cento tiveram diagnóstico de tireoidite. Dos laudos considerados inadequados, 70 por cento foram considerados hemorrágicos, sendo 30 por cento considerados hipocelulares. Os dados encontrados no nosso trabalho estiveram de acordo com os encontrados na literatura médica.

Theophylline Increases the Uptake of Radioiodine by Mouse Thyroid

Diagnostic and therapeutic use of radioiodine in the management of thyroid disorders depends on the ability of thyroid cells to concentrate radioiodine, a process that is regulated by the intracellular increase in cAMP. We hypothesized that theophylline, a drug known to increase intracellular cAMP via inhibition of phosphodiesterase, could increase thyroidal radioiodine uptake. We tested this effect in vivo, using C57BL/6j mice, and in vitro, using Fisher rat thyroid (FRTL-5) cells. One mouse received 2.5mg theophylline i.p., whereas a control mouse received only saline. Twenty-hours after theophylline, mice were injected with 10mu Ci Na(125)I in 0.1 mL saline through the tail vein. Mean thyroidal (125)I activity was 3.3-fold higher in theophylline-treated mice than in their respective controls. Radioiodine uptake and intracellular cAMP production of FRTL-5 cells were increased by a relatively low concentration of theophylline (1mu M). Intracellular cAMP increased up to 30 min and then declined in response to 1mu M theophylline. Sera from theophylline-treated mice stimulated (125)I uptake and intracellular cAMP production by FRTL-5 cells. These findings show that theophylline can enhance radioiodine uptake by thyrocytes in vivo and in vitro. The in vitro effects of theophylline on both radioiodine uptake and cAMP production in a dose-dependent manner are consistent with an action mediated by phosphodiesterase inhibition.

Effect of polyethylene glycol 4000 on adhesion formation following thyroid surgery in rats.

BACKGROUND & OBJECTIVES: Difficulties in dissection encountered during reoperative thyroid surgery could be minimised by preventing formation of adhesions in the operative field. We studied the prevention of adhesion formation in rats after thyroid surgery by using polyethylene glycol 4000 (PEG 4000). METHODS: Twenty two rats in two equal groups were studied. Right hemithyroidectomy was performed in both groups with 0.9 per cent saline being instilled in the operative field in the control group and PEG 4000 solution in the study group. After 10 days, all rats were re-explored and the remaining thyroid tissue of the right lobe was excised. The specimens were scored according to the thickness of the connective tissue over the remainder of the thyroid gland. RESULTS: The connective tissue thickness over the remaining tissue of the thyroid gland in the control and study groups was 272.04 +/- 77.10 and 172.90 +/- 48.92 microns respectively. The decrease of the connective tissue thickness over the remainder of thyroid gland in the study group was significant (P < 0.05). INTERPRETATION & CONCLUSION: In this animal model although application of PEG 4000 did not completely prevent adhesion formation, a significantly decreased amount of adhesions was found.

Punçäo aspirativa por agulha fina de nódulos tiróideos: revisäo da literatura com ênfase à punçäo orientada por ultra-sonografia / Aspiration puncture with fine needle of thyroid nodes: literature review with emphasis in punction guided by ultrasound

A punção aspirativa por agulha fina de nódulos tiróideos tem sido proposta como método de triagem pré-operatória para se reduzir o número de pacientes submetidos a cirurgia desnecessária. Alguns autores têm relatado alta acurácia e boa relação custo-benefício deste método para identificação de câncer em pacientes com lesões clinicamente palpáveis. Entretanto, este método apresenta algumas limitações quando os nódulos a serem examinados são pequenos ou de difícil acesso à palpação. O advento da ultra-sonografia de alta resolução tem revolucionado o diagnóstico dos nódulos tiróideos, sobretudo nesses casos. Talvez o maior avanço da ultra-sonografia seja a habilidade para orientar a biópsia por agulha fina. Vários estudos têm demonstrado que a análise combinada das características citológicas e aspectos morfológicos dos nódulos tiróideos palpáveis e não-palpáveis, proporcionada por essa técnica, melhora o diagnóstico preoperatório destas lesões.

Estradiol decreases iodide uptake by rat thyroid follicular FRTL-5 cells

Estradiol has well-known indirect effects on the thyroid. A direct effect of estradiol on thyroid follicular cells, increasing cell growth and reducing the expression of the sodium-iodide symporter gene, has been recently reported. The aim of the present investigation was to study the effect of estradiol on iodide uptake by thyroid follicular cells, using FRTL-5 cells as a model. Estradiol decreased basal iodide uptake by FRTL-5 cells from control levels of 2.490 0.370 to 2.085 0.364 pmol I-/æg DNA at 1 ng/ml (P<0.02), to 1.970 0.302 pmol I-/æg DNA at 10 ng/ml (P<0.003), and to 2.038 0.389 pmol I-/æg DNA at 100 ng/ml (P<0.02). In addition, 4 ng/ml estradiol decreased iodide uptake induced by 0.02 mIU/ml thyrotropin from 8.678 0.408 to 7.312 0.506 pmol I-/æg DNA (P<0.02). A decrease in iodide uptake by thyroid cells caused by estradiol has not been described previously and may have a role in goiter pathogenesis

Correlación ecográfica-patológica en patología nodular tiroidea / Pathologic-Ecografic correlation in pathology tyroid nodular

Se realizó un trabajo prospectivo entre marzo de 1998 a junio de 1999 en el Servicio de Cirugía General del Hospital Militar "Dr. Carlos Arvelo", Caracas Venezuela, analizando el estudio ecosonográfico (transductor lineal de 7,5 mghz, equipo General Electric, advantage III) tiroideo de 51 pacientes y correlacionándolo con 44 punciones aspiraciones con aguja fina (citológico) y con 13 biopsias (histológicas) quirúrgicas. Se agruparon a los pacientes en tres grupos; Nº1: imagen única hipoecoica con microcalcificaciones, Nº2: imagen única hipoecoica con halo ecolúcido sin microcalcificaciones con o sin zonas ecolúcidas en su interior (ecomixta), Nº3: imágenes multiples hipoecoicas con o sin halo ecolúcido; con o sin zonas ecolúcidas en su interior. Los pacientes del grupo Nº1 se catalogaron como procesos malignos, y los de los grupos restantes como procesos benignos. Del grupo Nº1 se obtuvo 4 casos, que correspondieron todos a adenocarcinoma papilar; del grupo Nº2 se encontraron 22 pacientes, con un solo caso de adenocarcinoma de células de Hurthle (falso negativo). Del grupo Nº3 se hallaron 25 pacientes, con diagnóstico de tumores benignos por citología e histología. La sensibilidad de la imagen B fue de 83 por ciento y la especificidad del 100 por ciento