Les tumeurs thyroïdiennes constituent les tumeurs endocrines les plus fréquentes. Parmi celles-ci, on distingue les adénomes, tumeurs bénignes et encapsulées, et les carcinomes, tumeurs malignes. Ceux-ci sont eux-mêmes subdivisés, principalement sur base histologique, en carcinomes papillaires ou folliculaires, qui conservent certaines caractéristiques de différenciation des cellules thyroïdiennes initiales dont ils dérivent, et qui peuvent évoluer en carcinomes anaplasiques, totalement dédifférenciés. Les carcinomes différenciés de la thyroïde sont généralement de bon pronostic, contrairement aux cancers anaplasiques qui sont nettement plus agressifs, avec un taux de survie à 5 ans inférieur à 5%. <p>La technologie des microarrays permet d’analyser simultanément l’expression de milliers de gènes dans différentes cellules et différentes conditions physiologiques, pathologiques ou toxicologiques. Au cours de cette thèse de doctorat, nous avons déterminé le profil d’expression génique des carcinomes papillaires de la thyroïde à l’aide de la technique des microarrays en utilisant une plateforme contenant plus de 8000 gènes. Douze des 26 cancers papillaires étudiés étaient issus de patients habitant la région de Tchernobyl lors de l’explosion de la centrale nucléaire de 1986 et sont considérés comme des cancers radio-induits. Les 14 tumeurs restantes proviennent de patients habitant la France. Leur étiologie n’étant pas connue, ils sont considérés comme des cancers sporadiques. <p>La réalisation de ces expériences nous a permis d’identifier des signatures moléculaires entre des sous-types de cancers papillaires. Premièrement, nous avons montré que malgré un profil d’expression génique global similaire entre les cancers papillaires sporadiques et radio-induits, une signature multigénique permet de les séparer, indiquant que des subtiles différences existent entre les deux types de tumeurs. Deux autres signatures indépendantes, l’une liée aux agents étiologiques présumés de ces tumeurs (radiation vs. H2O2), l’autre liée aux mécanismes de recombinaison homologue de l’ADN, permettent également de séparer les cancers post-Tchernobyl des cancers sporadiques. Nous avons interprété ces résultats comme une différence de susceptibilité à l’irradiation entre ces deux types de tumeurs. D’autre part, nous avons pu identifier une liste de gènes permettant de séparer les cancers papillaires à variante classique des autres sous-types de cancers papillaires. L’analyse de cette liste de gènes a permis de mettre en relation cette signature avec l’important remodelage de cette variante histologique par rapport aux autres. <p>Ces expériences ont aussi abouti à l’obtention d’une liste de gènes différentiellement exprimés entre les cancers papillaires et leur tissu normal adjacent. Une analyse minutieuse de cette liste à l’aide d’outils statistiques a permis de mieux comprendre la physiopathologie de ces tumeurs et d’aboutir à différentes conclusions :(1) un changement de population cellulaire est observé, avec une surexpression de gènes liés à la réponse immune, reflétant l’infiltration lymphocytaire de ces tumeurs par rapport au tissu normal adjacent (2) la voie de signalisation JNK est activée par surexpression de ses composants (3) la voie de signalisation de l’EGF, également par une surexpression de ses composants, complémente les altérations génétiques des cancers papillaires pour l’activation constitutive de la voie ERK1/2 (4) une sousexpression des gènes de réponse précoce est observée (5) une surexpression de nombreuses protéases, d’inhibiteurs de protéases et de protéines de la matrice extracellulaire permet d’expliquer l’important remodelage des cancers papillaires (6) le profil d’expression génique des cancers papillaires peut être corrélé avec un mode de migration collectif de ces tumeurs. <p>Finalement, dans la dernière partie de la thèse, nous avons déterminé le profil d’expression génique des cancers anaplasiques de la thyroïde et l’avons comparé à celui des cancers papillaires. Nous avons montré que les deux types de tumeurs présentent des profils moléculaires globaux distincts, reflétant leur comportement tumoral très différent. <p> / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished

Pendrina é um transportador de ânions inserido na membrana apical de células foliculares. Estudos subseqüentes demonstraram que a proteína pode mediar o efluxo apical do iodeto nos tirócitos. Sendo o iodo fundamental para a síntese de hormônios tiroidianos foi objetivo deste estudo avaliar o efeito da administração aguda de iodo na expressão do mRNA da proteína pendrina, em curtos períodos de tempo (30min à 24h).Ratos Wistar foram divididos em: controle e iodo, que receberam injeção de salina ou NaI, sendo decapitados após 30, 1 e 24h dessa administração.O RNA da tiróide foi extraído para a análise da expressão do mRNA da Pendrina por Real Time PCR e Northern Blot. Para o estudo in vitro utilizou-se a linhagem celular de tiróide de rato PCCl3, que foi tratada ou não com 10-3M de NaI. As células permaneceram sob tratamento por 30´, 1 e 24h, quando então o RNA foi extraído para análise da expressão por Real Time PCR.Houve aumento significativo do mRNA da Pendrina em todos os grupos, indicando que mecanismos foram desencadeados visando o efluxo do iodeto da célula. / Pendrin is a chloride/iodide exchange located at the apical membrane of thyrocytes. Mutations in its gene lead to a defect in iodide organification. This suggested that pendrin could function as an apical iodide transporter in this cells. Since iodine is essential for thyroid hormone synthesis, this study attempted to investigate that possibility by evaluating whether the acute iodide administration, from 30min up to 24h, could regulate the Pendrin mRNA expression. Rats received NaI or saline, and were sacrificed 30´, 1 and 24h later.Thyroid total RNA was extracted and Pendrin mRNA content was evaluated by Northern Blotting and Real-Time PCR. For in vitro study,PCCl3 rat thyroid cells were cultured and treated or no with 103M NaI. After 30´, 1 and 24h, the cells were harvested and total RNA was extracted. The mRNA content was evaluated by Real-Time PCR. The mRNA increased in all groups of study, indicating that excess of iodide leads to an activation of Pendrin gene transcription and as consequence increased efflux of this element.

A biópsia por agulha fina é um procedimento importante na investigação de tumores, considerado de baixo-custo, minimamente invasivo e ideal para o fornecimento de um diagnóstico preciso em casos de nódulos da glândula tireóide. Para a realização bem sucedida da biópsia por agulha, a exatidão é essencial e a prática proporciona benefícios significativos tanto na recuperação do paciente, quanto na obtenção de resultados acurados. Esta tese investigou a possibilidade do desenvolvimento de um simulador de realidade virtual para treinamento de biópsia guiada por ultrassom de nódulos da glândula tireóide. O simulador de realidade virtual proposto e desenvolvido é também uma ferramenta educativa, pois além de praticar o procedimento, o usuário pode visualizar tanto um modelo da tireóide para sentir sua textura, quanto um modelo completo do pescoço com todos os seus órgãos internos, podendo ser rotacionado. O sistema consiste de duas interfaces: uma tridimensional, apresentando os modelos virtuais com estereoscopia na mesa de visualização, cuja interação do usuário é feita através do teclado ou dispositivo háptico (Phantom OmniTM); e uma segunda que simula o exame de ultrassom, com todas as funcionalidades de um exame real, sendo manipulada pelo mouse. As duas se comunicam e todo o processo é mostrado na janela do instrutor, que substitui o supervisor orientando o usuário durante o treinamento. O simulador de realidade virtual foi avaliado experimentalmente por profissionais da área médica e tecnológica, sendo aprovado como uma ferramenta para treinamento e ensino de biópsia de nódulos da glândula tireóide. / The fine needle biopsy is an important procedure to investigations in tumors, low-cost considered, minimally invasive and ideal for supplying an accurate diagnosis in cases of thyroid gland nodules. The exactness is essential for the successful accomplishment of the needle biopsy and the practice provides significant benefits in the recovery of the patient, as well as in attainment of accurate results. This thesis investigated the possibility of the development of virtual reality simulator for the training of the ultrasound guided needle biopsy of thyroid gland nodules. The proposed and developed virtual reality simulator is also an educative tool, because besides practicing the procedure, the user can visualize thyroid model to feel its texture, as well as a complete model of the neck with all its internal organs and it can be rotated. The system consists of two interfaces: first is a three-dimensional which presents the virtual models with stereoscopy in the visualization table, whose interaction of the user is made through the keyboard or haptic device (Phantom OmniTM); and second one that simulates the ultrasound images, with all the functionalities of a real examination, manipulated by the mouse. The two interfaces communicate with each other and all the process is shown in the instructor window that substitutes the supervisor and guides the user during the training. The virtual reality simulator was experimentally evaluated by professionals of the medical and technological areas, being approved as a tool for training and education in needle biopsy of the thyroid gland nodules.

A disfunção tireoidiana durante a gestação cursa com maior morbidade materno-fetal. A deficiência de iodo continua sendo uma causa importante de disfunção tireoidiana. O estado de São Paulo é considerado uma região suficiente em iodo. No entanto, as gestantes são consideradas grupo de risco para deficiência iódica devido a maior necessidade de produção dos hormônios tireoidianos ao longo da gestação. Este trabalho objetiva avaliar a suficiência iódica de gestantes residentes em São Paulo e correlacionar as concentrações de iodo com os valores dos hormônios tireoidianos em cada trimestre de gestação. Métodos: Foi realizado estudo transversal com gestantes em pré-natal de baixo risco nos três trimestres de gestação. Foram analisadas 251 mulheres sem doença tireoidiana prévia ou atual, com autoanticorpos antitireoidianos negativos e que não estavam em uso de polivitamínico contendo iodo. A concentração de iodo urinário foi feita em amostra isolada pelo método Sandell- Kolthoff. As dosagens de TSH, T4, T3, T4 livre (T4L), T3 livre (T3L), tireoglobulina (TG), globulina ligadora da tiroxina (TBG) anticorpo antitireoperoxidase (AntiTPO), antitireoglobulina (AntiTG), estradiol e hCG foram feitas por método eletroquimioluminescente. Ultrassonografia da tireoide foi realizada com aparelho Philips IU-22 e transdutor 7,5-12 mHz. Resultados: Os valores de TSH correspondentes aos percentis 2,5 e 97,5 foram 0,38 uIU/mL e 4,23 uIU/mL, respectivamente. Observou-se valores de TSH > 2,5-3,0 uIU/mL em 13,1% gestantes. Valores de TSH > 4 uIU/mL foi observado em 3,6% dos casos. Os valores de T4T e T3T correspondentes aos percentis 2,5 e 97,5 foram 7,8 ug/dL e 16,1 ?g/dL; 122 ng/dL e 249 ng/dL, respectivamente. Os valores de T4l e T3l correspondentes aos percentis 2,5 e 97,5 foram 0,76 ng/dL e 1,42 ng/dL; 0,21 ng/dL e 0,36 ng/dL, respectivamente. Houve aumento significativo na relação T3:T4 ao longo dos trimestres e, em 8% das amostras, essa relação estava acima do valor de referência para gestantes. As dosagens de iodúria não apresentaram diferenças estatísticas entre os três trimestres da gestação. As medianas foram 135ug/L, 153ug/L e 140ug/L, respectivamente. Encontramos iodúria < 150ug/L em 52,2% das gestantes. Comparando o grupo com iodúria < 150ug/L (deficiente em iodo) e o grupo com iodúria entre 150-250ug/L (suficiente em iodo), observou-se diferença significativa nos valores de TSH e de T3 nas gestantes do 2o Trimestre (média de TSH = 2,24 uIU/mL e TSH = 1,78 uIU/mL e média de T3 = 196 ng/dL e T3 = 181 ng/dL entre o grupo deficiente e suficiente, respectivamente). Não houve diferenças significativas entre os valores de TG e o volume tireoidiano ao longo dos trimestres. Conclusão: A frequência de hipotireoidismo subclínico variou de 3,6% a 13,1%, dependendo dos critérios adotados. Não foi possível estabelecer a frequência de hipotiroxinemia materna, devido à ausência de valores de corte de T4l estabelecido na nossa população. Foi encontrada deficiência iódica em 52,2% das gestantes avaliadas. Embora estas gestantes apresentem deficiência leve de iodo, foram necessários mecanismos adaptativos para equilibrar a função tireoidiana materna com possível produção preferencial de T3, aumento da relação T3:T4 e valores mais elevados de TSH. Conclui-se que, embora esta seja uma região suficiente em iodo, as mulheres poderiam se beneficiar com a suplementação deste nutriente durante a gestação / Thyroid dysfunction in pregnancy is associated with increased rate of obstetrical and neonatal adverse outcomes. Iodine deficiency continues to be a major cause of thyroid dysfunction. The state of São Paulo is considered a sufficient iodine region. However, pregnant women are considered a risk group for iodine deficiency due to an increased demand for production of thyroid hormones throughout pregnancy. This study aims to evaluate the iodine sufficiency of pregnant women in São Paulo and to correlate iodine concentrations with thyroid parameters in each trimester of gestation. Methods: A cross-sectional study was carried out with low-risk pregnant women in the three trimesters of gestation. We analyzed 251 women without history of thyroid disease, with negative antithyroid autoantibodies (anti TPO and anti TG) and who were not taking iodine supplementation. The urinary iodine concentration (UIC) was measured by the Sandell-Kolthoff digestion method in casual morning urine samples. Serum TSH, T4, T3, free T4 (FT4), free T3 (FT3), thyroglobulin (TG), TBG, anti-TPO, anti-TG, estradiol and hCG were measured by the electrochemiluminescence method. Thyroid ultrasound was performed with Philips IU-22 and 7.5-12 mHz transducer. RESULTS: The TSH values corresponding to the 2.5 and 97.5 percentiles were 0.38 IU/mL and 4.23 IU/mL, respectively. TSH levels > 2.5-3.0 IU/mL were observed in 13.1% pregnant women. TSH values > 4 IU/mL were observed in 3.6% of the cases. The T4T and T3T values corresponding to the 2.5 and 97.5 percentiles were 7.8 ug/dL and 16.1 ug/dL; 122 ng/dL and 249 ng/dL, respectively. The FT4 and FT3 values corresponding to the 2.5 and 97.5 percentiles were 0.76 ng/dL and 1.42 ng/dL; 0.21 ng/dL and 0.36 ng/dL, respectively. There was a significant increase in the T3:T4 ratio over the trimesters and in 8% of the samples it was above the reference value for pregnant women. The dosages of UIC did not present statistical differences between the three trimesters of gestation. The medians were 135 ug/L, 153 ug/L and 140 ug/L, respectively. We found UIC < 150 ?g/L in 52.2% of pregnant women. Comparing the group with UIC < 150 ?g/L (iodine deficient) and the group with UIC between 150-250 ug/L (sufficient in iodine), a significant difference was observed in TSH and T3 values in the 2nd trimester (TSH = 2.24 IU/mL and TSH = 1.78 IU/mL and mean T3 = 196 ng/dL and T3 = 181 ng/dL between the deficient and sufficient groups, respectively). There were no significant differences between TG values and thyroid volume over the trimesters. Conclusion: The subclinical hypothyroidism frequency ranged from 3.6% to 13.1%, depending on the adopted criteria. It was not possible to establish frequency of maternal hypothyroxinemia, due to the absence of FT4 cutoff established in our population. Iodine deficiency was found in 52.2% of pregnant women evaluated. Although these pregnant women presented mild iodine deficiency, adaptive mechanisms were necessary to balance thyroid function with possible preferential production of T3, increase in T3:T4 ratio and higher values of TSH. It is concluded that although this is an iodine sufficient region, women could benefit from supplementation of this nutrient during pregnancy

INTRODUÇÃO: O carcinoma papilífero da glândula tireoide é a neoplasia maligna endócrina mais prevalente com incidência em torno de 95%. Apresenta alto índice de disseminação linfática cervical, principalmente para os linfonodos do compartimento central ipsilateral, no nível VI, sendo os paratraqueais e os pré-traqueais os mais acometidos. Porém, existe uma área específica, não descrita nos compêndios anatômicos, que também é sede de metástase e de recidiva tumoral e está localizada entre o nervo laríngeo recorrente direito e as artérias carótida comum direita e tireóidea inferior direita. Uma abordagem cirúrgica nessa área causa maior morbidade devido à anatomia topográfica entre essas estruturas e os linfonodos ali localizados. Dessa forma, essa área pouco explorada é objetivo desse estudo, que pretende comparar dados antropométricos e demográficos com a presença ou não de linfonodos. MÉTODOS: Estudo anatômico transversal, com dissecção de 32 cadáveres não formalizados do Serviço de Verificação de Óbitos da Capital, onde se dissecou a região cervical à direita até a exposição da região localizada entre o nervo laríngeo recorrente direito e as artérias carótida comum direita e tireóidea inferior direita, com subsequente ressecção em bloco do tecido fibrogorduroso dessa região para análise dos linfonodos após preparação específica para esse fim. RESULTADOS: As características demográficas da população estudada foram as seguintes: Idade(anos): 66,75 ± 13,89; Sexo: masculino 20/32 (62,5%) e feminino 12/32 (37,5%); Peso (Kg): 63,1 ± 12,36; Altura (metros): 1,66 ± 0,09; IMC (Kg/m2): abaixo do peso 5/32 (15,6%), normal: 20/32 (62,5%), obeso: 3/32 (9,4%), obesidade mórbida: 4/32 (12,5%); Raça: branca 21/32 (65,62%), negra 10/32 (31,25%), amarela 1/32 (3,12%); Dados antropométricos: brevilineo 8/32 (25%), normolíneo 15/32 (46,88%), longilíneo 9/32 (28,12%). A presença de linfonodos em 22/32 (68,75%), IC 95%, nos casos em que se encontraram linfonodos, a média foi de 1,65 ± 0,29 linfonodos por cadáver. Presença de linfonodos em cadáveres classificados como normolíneos, pelo teste exato de Fischer (p=0,03) e da raça branca, pelo teste exato de Fischer (p=0,04). Não se observou relação entre IMC e a presença de linfonodos, pelo teste de Sperman (p=0,461). CONCLUSÕES: A presença de linfonodos foi confirmada em 22/32 das espécimes estudadas (68,75%); Quanto às características dos linfonodos encontrados, o número variou de zero a 6 e, contando somente os casos em que os linfonodos foram achados, a média foi de 1,65 ± 0,29 linfonodos por cadáver. O tamanho variou de 0,9 a 5,39 mm no diâmetro transverso e de 1,36 a 11,64 mm no diâmetro longitudinal. Houve correlação antropométrica com presença de linfonodos nos cadáveres considerados normolíneos (p=0,03) e da raça branca (p=0,04) / INTRODUCTION: The papillary carcinoma of thyroid gland is the most prevalent endocrin malignant neoplasm, whose incidence is around 95%. This type of cancer causes increased likelihood of lymphatic spread in neck region, mainly to lymph nodes of the ipsilateral central compartiment, in level VI, such as the paratraqueal and the pretraqueal lymph nodes. However, there is a specific area, not described in the anatomic literature, that is receptor of metastasis and of tumor recurrences and is located among the right recurrent laryngeal nerve and the right common carotid and right inferior thyroid arteries. A surgical approach in this area causes more morbidity because of the topographic anatomy among those structures and the lymph nodes located there. Thus, this unexplored area is objective of this scientific study, which pretends to compare anthropometric and demographic data with the lymph nodes presence or absence. METHODS: Cross-sectional anatomic study, with dissection of 32 non-preserved corpses from the Serviço de Verificação de Óbitos da Capital, this study there had happened dissection of the right neck region until the exposition of the region located among the right recurrent laryngeal nerve and the right common carotid and right inferior thyroid arteries. Moreover, there was made resection in block of fibroadipose tissue of this region to analyse the lymph nodes after being prepared with specific material for this goal. RESULTS: Those are the demographic characteristics of this studied population: Age (in years): 66,75 ±13,89; Gender: male 20/32 (62,5%) and female 12/32 ( 37,5%); Weight(Kg): 63,1 ± 12,36; Height(meters): 1,66 ± 0,09; BMI (body mass index) (Kg/m2): underweight 5/32 (15,6%), normal: 20/32 (62,5%); obese: 3/32 (9,4%); morbid obesity: 4/32 (12,5%); Race: caucasian 21/32 (65,62%), afrodescendants 10/32(31,25%), asian 1/32 (3,12%); anthropometric data: brevilineo 8/32 (25%), normolineo 15/32 (46,88%), longilineo 9/32 (28,12%). There are lymph nodes in 22/32 (68,75%); Confidence Interval 95%, in the cases that lymph nodes were found, the average was 1,65 ± 0,29 lymph nodes for each corpse. There are lymph nodes in corpses classified as normolineos by accurate Ficher\'s Test(p= 0,03) and of the white race by accurate Ficher\'s Test(p=0,04). There is no observed correlation between BMI and lymph nodes found, by Spearman\'s correlation test( p=0,461). CONCLUSIONS: lymph nodes were found in 22/32 studied corpses (68,75%). 0 to 6 is the gap of the number of lymph nodes found in the same body. In those bodies which lymph nodes were found, the average is 1,65 ± 0,29 lymph nodes for each body. Their size varies from 0,9 to 5,39 mm in the transversal diameter and from 1,36 to 11,64 mm in the longitudinal diameter. There is a anthropometric correlation with lymph nodes presence in corpses considered as normolineos(p=0.03) and of the white race (p=0,04)

Os microRNAs são pequenos RNAs importantes na modulação da expressão gênica. O carcinoma papilífero de tireoide (CPT) é responsável pela maior parte dos casos de câncer de tireoide. Mutações somáticas ativam as vias de MAPK e PI3K/AKT e exercem papel importante no desenvolvimento do CPT. Acredita-se que miRNAs regulem genes associados a essas vias. A expressão de miRNAs foi avaliada em amostras parafinadas de CPT caracterizadas quanto à presença da mutação BRAFV600E. A expressão de miRNAs variou devido à heterogeneidade dos tecidos emblocados e entre pacientes, dados importantes quando microRNAs são avaliados como biomarcadores. Microarranjos de DNA mostraram diferenças na expressão de miR-16, miR-19a, miR-21, miR146a, miR-146b, miR-221 e miR-222 entre amostras positivas e negativas para BRAFV600E, indicando um possível papel na modulação de vias influenciadas por esta mutação. Quando amostras adicionais foram analisadas, apenas miR-146b apresentou expressão diferencial entre os dois grupos, ressaltando a variabilidade entre pacientes quanto à expressão de miRNAs. / MicroRNAs are small non-coding RNAs that regulate protein-coding genes. Papillary thyroid cancer (PTC) accounts for most of the thyroid cancer cases. Somatic mutations activate MAPK and PI3K/AKT pathways and play a leading role in PTC. MiRNAs may contribute to the regulation of these pathways. We studied the expression of miRNAs in formalin-fixed, paraffin-embedded (FFPE) PTC samples submitted to mutation characterization. Our results show that miRNA expression varies due to embedded sample heterogeneity and that there is great variability in miRNA expression among patients, both important issues when miRNA expression is evaluated as a biomarker. DNA microarray experiments compared BRAFV600E positive and negative samples. MiR-16, miR-19a miR-21, miR146a, MiR-146b, miR-221 and miR-222 were deregulated, indicating a possible implication in BRAF-related pathways. When additional samples were evaluated, only miR-146b presented consistent variation in expression, highlighting variability among patients

Uma série de 205 casos de lesões nodulares da tireóide foi revista morfologicamente de acordo com a nova classificação da Organização Mundial da Saúde (OMS, 2004) e analisada quanto à imuno-expressão das citoqueratinas 14 (CK 14) e 19 (CK19) e de citocromo-oxidase. Especial ênfase foi dada à avaliação da oxifilia nos nódulos, valorizando não só a oxifilia clássica (mais de 75% de células oncocíticas), mas também o que aqui chamamos de oxifilia parcial, e ao diagnóstico dos tumores foliculares de potencial incerto de malignidade. Amostras parafinadas dissecadas de carcinomas foram analisados para mutações dos genes BRAF e RAS (H-RAS, KRAS e N-RAS) mediante PCR, SSCP e seqüenciamento e para rearranjo dos genes PAX8-PPARg mediante FISH e RT-PCR. A oxifilia esteve presente, com freqüência variável, em todos os subtipos de nódulos da tireóide, benignos e malignos: 20,7 a 69,7% dos nódulos exibiram oxifilia clássica e 58,6 a 90,6% oxifilia de qualquer intensidade (clássica ou parcial). A imuno-expressão de citocromo-oxidase mostrouse associada ao achado morfológico de oxifilia, principalmente nos nódulos benignos e nos carcinomas foliculares. A CK 19 apresentou reatividade intensa apenas nos carcinoma papilíferos e em um caso de carcinoma folicular com áreas sugestivas de evolução para carcinoma pouco diferenciado. Houve associação significativa entre o diagnóstico de carcinoma papilífero e expressão de CK19 (p<0.001), mas a associação entre oxifilia e expressão de CK 19 não foi significativa. Nos carcinomas papilíferos, a oxifilia ausente ou parcial associou-se a maior freqüência de multicentricidade e a oxifilia clássica à maior idade média dos pacientes. A mutação do gene BRAF (V600E) esteve presente apenas nos carcinomas papilíferos e não teve influência nas variáveis clínico-patológicas. O rearranjo PAX8-PPARg teve incidência nas lesões foliculares oncocíticas (22,2%) bem superior à relatada na literatura. Associou-se a menor idade média dos pacientes e menor diâmetro tumoral nos carcinomas foliculares. A presença de mutações do RAS nas lesões foliculares associou-se significativamente com invasão capsular e oxifilia parcial. Todas os padrões de alterações moleculares, embora presentes, foram menos freqüentes nos tumores oncocíticos. Nossos resultados evidenciam que a oxifilia é muito freqüente em todos os subtipos de nódulos da tireóide, inclusive nos recém-descritos tumores foliculares de potencial incerto de malignidade. Merece destaque o fato de, nas lesões foliculares, a presença de oxifilia, especialmente em sua forma clássica, ter sido significativamente mais freqüente nos carcinomas, seguidos dos tumores foliculares de potencial incerto, sendo menos prevalente nos adenomas foliculares. Embora a oxifilia tenha sido associada com menor freqüência de mutações nos genes BRAF, RAS e rearranjo PAX8-PPARg, a detecção de sua coexistência com estas mutações e a presença freqüente de oxifilia em todos os tipos de nódulos da tireóide favorecem o conceito de que a oxifilia e a tumorigênese possam ser eventos distintos, muitas vezes paralelos. / A series of 205 thyroid nodules was morphologically reviewed according to the new World Health Organization (WHO, 2004) classification and analyzed regarding the immunoexpression of cytokeratins 14 (CK14) and 19 (CK19) and mitochondrial enzyme cytochrome oxidase. Special emphasis was given to the oxyphilia evaluation in the nodules, concerning not only the classical oxyphilia (more than 75% of oncocytic cells) but also the presence of smaller amounts of oncocytic cells, named herein partial oxyphilia, and to the recently purposed diagnosis of follicular tumours of unknown malignancy potential. Dissected paraffin-embedded samples of carcinomas were screened for BRAF and RAS mutations (H-RAS, K-RAS and NRAS) by PCR, SSCP and direct sequencing, whereas FISH and RT-PCR were used for assessment of PAX8-PPARg rearrangement. The oxyphilia was present, with heterogeneous frequence, in all subtypes of thyroid nodules: 20.7 to 69.7% of the nodules showed classical oxyphilia and 58.6 to 90.6% of them, oxyphilia of any intensity (classical or partial). The immunoexpression of cytochrome-oxidase was associated to the morphological finding of oxyphilia, especially in benign nodules and in follicular carcinomas. CK19 showed intense reactivity only in papillary carcinomas and in one case of follicular carcinoma with areas that could be already poorly differentiated. There was a significant association between the diagnosis of papillary carcinoma and CK 19 expression (p<0.001), but the association between oxyphilia and CK 19 expression was not statistically significant. Papillary carcinomas without or with partial oxyphilia were associated to a higher frequency of multicentricity and those with classical oxyphilia to older mean ages of patients. The BRAF gene mutation (V600E) was present only in papillary carcinomas and had no influence on clinical-pathological variables. The PAX8-PPARg rearrangement rates in oncocytic follicular lesions were higher than those previously reported. This rearrangement was associated to a younger mean age of patients and to smaller follicular carcinomas. The presence of RAS mutations in follicular lesions was significantly associated to capsular invasion and partial oxyphilia. All patterns of molecular alterations assessed herein, although present, were less frequent in oncocytic tumours. Our study further demonstrates the prevalence of classical and partial oxyphilia within all subtypes of thyroid nodules, including the recently described follicular tumours of unknown malignancy potential. A remarkable finding is that, among follicular neoplasms, oxyphilia, especially in classical pattern was significantly more prevalent in carcinomas, intermediate in follicular tumours of unknown malignancy potential and less common in adenomas. The absence of a significative relationship between oxyphilia and malignancy in most nodules is noteworthy. However, an association between oxyphilia and malignancy was observed in follicular neoplasms. Although oxyphilia has been associated with a lower mutation frequency in BRAF and RAS genes and PAX8- PPARgrearrangement, it can coexist with these mutations. This finding and the high prevalence of oxyphilia in all subtypes of thyroid nodules support the concept that oxyphilia and tumourigenesis can be distinct, and many times, parallel events.

A biópsia por agulha fina é um procedimento importante na investigação de tumores, considerado de baixo-custo, minimamente invasivo e ideal para o fornecimento de um diagnóstico preciso em casos de nódulos da glândula tireóide. Para a realização bem sucedida da biópsia por agulha, a exatidão é essencial e a prática proporciona benefícios significativos tanto na recuperação do paciente, quanto na obtenção de resultados acurados. Esta tese investigou a possibilidade do desenvolvimento de um simulador de realidade virtual para treinamento de biópsia guiada por ultrassom de nódulos da glândula tireóide. O simulador de realidade virtual proposto e desenvolvido é também uma ferramenta educativa, pois além de praticar o procedimento, o usuário pode visualizar tanto um modelo da tireóide para sentir sua textura, quanto um modelo completo do pescoço com todos os seus órgãos internos, podendo ser rotacionado. O sistema consiste de duas interfaces: uma tridimensional, apresentando os modelos virtuais com estereoscopia na mesa de visualização, cuja interação do usuário é feita através do teclado ou dispositivo háptico (Phantom OmniTM); e uma segunda que simula o exame de ultrassom, com todas as funcionalidades de um exame real, sendo manipulada pelo mouse. As duas se comunicam e todo o processo é mostrado na janela do instrutor, que substitui o supervisor orientando o usuário durante o treinamento. O simulador de realidade virtual foi avaliado experimentalmente por profissionais da área médica e tecnológica, sendo aprovado como uma ferramenta para treinamento e ensino de biópsia de nódulos da glândula tireóide. / The fine needle biopsy is an important procedure to investigations in tumors, low-cost considered, minimally invasive and ideal for supplying an accurate diagnosis in cases of thyroid gland nodules. The exactness is essential for the successful accomplishment of the needle biopsy and the practice provides significant benefits in the recovery of the patient, as well as in attainment of accurate results. This thesis investigated the possibility of the development of virtual reality simulator for the training of the ultrasound guided needle biopsy of thyroid gland nodules. The proposed and developed virtual reality simulator is also an educative tool, because besides practicing the procedure, the user can visualize thyroid model to feel its texture, as well as a complete model of the neck with all its internal organs and it can be rotated. The system consists of two interfaces: first is a three-dimensional which presents the virtual models with stereoscopy in the visualization table, whose interaction of the user is made through the keyboard or haptic device (Phantom OmniTM); and second one that simulates the ultrasound images, with all the functionalities of a real examination, manipulated by the mouse. The two interfaces communicate with each other and all the process is shown in the instructor window that substitutes the supervisor and guides the user during the training. The virtual reality simulator was experimentally evaluated by professionals of the medical and technological areas, being approved as a tool for training and education in needle biopsy of the thyroid gland nodules.

A naturally occurring disease involving hyperplasia of the thyroid gland and a consistent pattern of musculoskeletal deformities of newborn foals in western Canada was first described in 1981. This disease was an important cause of foal mortality and, therefore, reproductive loss throughout western Canada during the 1990s and has since been recognized in western Ontario and the northwestern United States. A series of investigations were conducted to describe, characterize, and attempt to determine the pathogenesis and cause of this syndrome. Affected foals were typically born after a long gestation (x = 360 days, range = 340 to 400 days), were diagnosed as hypothyroid based on a poor response to the administration of thyroid-stimulating hormone, and had various musculoskeletal lesions of which mandibular prognathism, flexural deformities and rupture of tendons of the limbs, and incomplete ossification of the carpal and tarsal bones were present most commonly. In spite of the normal to long gestation, foals had signs of immaturity, were usually weak and unable to stand, became septic, and died or were euthanatised. Similar histories, clinical findings, and lesions were present in surgically created hypothyroid foals that were thyroidectomized in utero at about 210 days gestation. These findings supported the conclusion that foals which naturally developed these lesions were also hypothyroid in utero and that all the lesions present in affected foals were the result of the hypothyroidism and not of an underlying concurrent disease process. A case-control study was conducted to identify risk factors for naturally occurring congenital hypothyroidism. Information from congenitally hypothyroid foals concerning foal and dam signalment, farm environment, and dam management was compared with that from normal foals. Pregnant mares fed greenfeed, not supplemented with mineral, that left their "home farm" during gestation, or grazed irrigated pasture, had a 13.1 (<i>P</i>=0.0068), 5.6 (<i>P</i>=0.0472), 4.3 (<i>P</i>=0.0076) and approximately 15.3 (<i>P</i>=0.0245) times greater odds, respectively, of producing a congenitally hypothyroid foal than mares not exposed to these factors. Greenfeed often contains high levels of nitrate (NO₃^-) which is known to impair thyroid gland function. In light of this, forage samples from participating farms were analysed for nitrate levels. The odds of one or more congenitally hypothyroid foal being born on a farm feeding forage with at least a trace of nitrate was 8.0 times greater (<i>P</i>=0.0873) than the odds of the disease occurring a farm that fed forage free of nitrate. Further, the odds of a mare producing an affected foal when fed forage containing at least a trace of nitrate was 5.9 times greater (<i>P</i>=0.0007) than a mare fed nitrate-free forage.This study suggests that congenital hypothyroidism in foals may result from diets containing nitrate or low in iodine being fed to pregnant mares. These results need to be confirmed through further field investigations and controlled experiments. However, if they are accurate, there is cause for concern that other livestock raised in areas where congenitally hypothyroid foals occur may be exposed to the same dietary risk factors and may suffer similar disease.

published_or_final_version / abstract / toc / Surgery / Master / Master of Philosophy