No description available.

No description available.

No description available.

No description available.

Forkhead (Fox) proteins are transcription factors that function in many processes including development, metabolism and cell cycle regulation. This gene family is divided into subfamilies that appear to originate from a common ancestor. I have identified the evolutionary selection pressures acting on individual amino acid positions in the FoxA, FoxC, FoxD, FoxI, FoxO and FoxP subfamilies. The patterns of selection observed allowed for the prediction of residue function and identification of residues that differentiate orthologs and paralogs. The subfamily structure and negative selection found within the subfamilies indicates that after gene duplication, differentiation of subfamilies through amino acid changes and subsequent negative selection on these changes has occurred. Meanwhile, the observed neutral changes and positive selection allow for further protein differentiation. Within the FoxC subfamily, positive selection was identified at one amino acid site in the inhibitory domain. Mutation of this site in FOXC1 alters transactivation activity and the effects of mutants on transactivation activity are different on different reporters. The mutant effects were consistent with those of known disease causing mutations, supporting the predicted positive selection. The inhibitory domain is known to function in reducing FOXC1 transactivation activity and influences protein stability. Here I additionally show that loss of the inhibitory domain and mutation of the positively selected site can reduce FOXC1 DNA binding. Co-transfection of FOXC1 and TLE4, a repressor protein that can potentially bind to the inhibitory domain, was shown to increase FOXC1 transactivation activity. The effects of a novel disease causing FOXC1 inhibitory domain mutation on FOXC1 function were also assessed. The mutation reduced FOXC1 transactivation activity and increased protein half-life both of which may lead to disease. Regulation of FOXC1 activity is critical for normal function and this work has furthered our knowledge of how the inhibitory domain influences FOXC1 activity. I have provided biological evidence for the theory that positive selection acts at the amino acid level to optimize protein function. I have also shown that both changes in transcription factor proteins and the cis-regulatory region of target genes have the potential to contribute to evolutionary adaptation.

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2008. / Härtill 4 uppsatser.

Context: Inferior vena cava (IVC) anomalies have a 0.5% incidence rate and could be associated with other congenital abnormalities. In later stage of the disease, trophic ulcers with or without deep vein thrombosis (DVT) is consistent finding.Case Report: A 29-year-old male patient presented with recurrent lower extremity ulcers. Further workup revealed an absent infrahepatic inferior vena cava, prominently dilated azygos and hemiazygos veins with enlarged retroperitoneal collaterals without DVT.Conclusion: IVC anomaly should be suspected in a young patient presenting with unexplained venous thrombosis and recurrent ulcers of a lower extremity. IVC anomaly would inherently lead to blood flow stasis and endothelial injury. Thus per Virchow's triad, other risk factors for hypercoagulability such as physical inactivity, smoking tobacco, oral contraceptive pills should be avoided and when hereditary thrombophilias or other irreversible risk factors are present, lifelong anticoagulation should be considered.

No description available.

INTRODUÇÃO: O hipotireoidismo congênito (HC) é uma doença, de acometimento neonatal, caracterizada por diminuição nos níveis de hormônios tireoidianos. As causas mais comuns de HC primário permanente são as alterações no desenvolvimento da glândula tireóide (disgenesia) e os defeitos de síntese dos hormônios tireóideos (disormonogênese). A determinação da etiologia do HC tem papel importante na determinação da gravidade da doença, evolução e tratamento. Essa investigação é feita através de exames como ultrassonografia e cintilografia (CINT) da tireóide. Além disso, com o conhecimento do genoma humano, diversas mutações foram descritas, sendo a investigação molecular importante para a determinação da etiologia da doença. OBJETIVOS: 1. Determinar o diagnóstico etiológico dos pacientes com HC a partir de dosagens hormonais, tireoglobulina e exames de imagem; 2. Estabelecer a importância do uso da ultrassonografia com Doppler colorido (USDC) no diagnóstico etiológico; 3. Estabelecer a importância do uso do teste do perclorato de sódio intravenoso (PSIV) no diagnóstico diferencial de HC por disormonogênese; 4. Estudar os genes PAX8 e receptor do TSH (TSHR) em pacientes com HC causado por disgenesia tireoidiana MÉTODOS: Avaliamos 40 pacientes acompanhados na APAE - São Caetano com diagnóstico de HC primário e permanente acima de 3 anos de idade. Os pacientes realizaram dosagens de T3, T4, T4 livre, TSH, tireoglobulina (TG) e anticorpo anti-TG pelo método imunofluorimétrico, além de USDC e CINT. Os pacientes com suspeita de disormonogênese foram submetidos ao teste PSIV e avaliação com otorrinolaringologista e audiometria tonal, se necessário. Os pacientes que apresentavam disgenesia tireoidiana tiveram o DNA extraído a partir de leucócitos periféricos para o estudo dos genes PAX8 e TSHR através de PCR e sequenciamento automático. RESULTADOS: Avaliamos 28 pacientes do sexo feminino e 12 do sexo masculino, após suspensão do tratamento com levotiroxina por 4 semanas. A idade média foi de 6,5 anos. O TSH médio foi 129,9 UI/mL (normal: 0,7-6,0). Os valores de T3, T4 e T4 livre variaram de 14 217 ng/dL (normal: 105-269), <1,6 15,8 g/dL (normal: 1,5-15) e < 0,3 2,7 ng/dL (normal: 0,7-1,5), respectivamente. A TG variou de <1 287 ng/dL (normal: 1,7-35). A USDC mostrou 21 pacientes com tireóide tópica (53%), 8 pacientes com tireóide ectópica (20%) e 11 pacientes com atireose (27%). Na CINT, o mapeamento identificou tireóide tópica em 20 pacientes (51%), tireóide ectópica em 13 pacientes (32%), e atireose em 7 pacientes (17%). A captação mostrou-se aumentada em 2 horas em 10 pacientes. O teste PSIV foi realizado em 9 pacientes com bócio ou glândula de tamanho normal ao USDC, cuja captação foi aumentada. Apenas um paciente apresentou vômito ao início do teste. Seis pacientes apresentaram teste positivo, considerando uma queda maior que 20%. Nenhum desses pacientes apresentava surdez neurossensorial. Encontramos discrepância entre USDC e CINT em 9 pacientes, principalmente nos casos de ectopia. A dosagem de TG auxiliou na confirmação de atireose. Os níveis mais altos de TG encontrados foram nos casos de disormonogênese causados por defeito na organificação. Assim, determinamos o diagnóstico de ectopia em 32,5% dos pacientes, hipoplasia em 20%, defeito na organificação (defeito de TPO ou THOX2) em 17,5%, atireose em 15%, defeito na TG em 7,5% e 3 casos a esclarecer (7,5%). Vinte e sete pacientes foram diagnosticados como portadores de disgenesia tireoidiana e não apresentaram mutações nos genes PAX8 e TSHR. CONCLUSÃO: Estabelecemos o diagnóstico etiológico em 37 dos 40 pacientes estudados. A USDC mostrou-se importante no diagnóstico etiológico do HC, especialmente associada à dosagem de TG. O teste PSIV mostrou-se seguro no diagnóstico diferencial do HC por disormonogênese. Não identificamos nenhuma mutação nos genes PAX8 e TSHR nos casos estudados de disgenesia / INTRODUCTION: Congenital hypothyroidism (CH) is a disease at neonatal period characterized by low thyroid hormones levels. Most common causes of primary CH are alterations at thyroid gland development (dysgenesis) and thyroid hormone synthesis defects (dyshormonogenesis). The establishment of CH etiology has important role to define the severity, evolution and treatment of the disease. This investigation is based on thyroid ultrasound and radiouptake and radionuclide imaging (RAIU). With human genome knowledge, several mutations were described, becoming molecular investigation so important to etiology definition. OBJECTIVES: 1. Establish the etiologic diagnosis of CH patients using hormonal measurements, thyroglobulin and imaging exams. 2. Establish the importance of color Doppler ultrasound (CDUS) in etiologic diagnosis. 3. Establish the importance of intravenous perchlorate sodium test in differential diagnosis of CH due to dyshormonogenesis. 4. Study PAX8 and TSH receptor (TSHR) genes in patients with CH due to thyroid dysgenesis. METHODS: We evaluated forty patients followed-up at APAE - São Caetano with primary and permanent CH diagnosis above 3 years-old. Patients performed T3, T4, free T4, TSH, thyroglobulin (TG) and anti-TG antibody using immunofluorimetric assays, besides thyroid CDUS and RAIU. Patients with thyroid dysgenesis had their DNA extracted from peripheral leukocytes to study PAX8 and TSHR genes using PCR and automatic sequencing. Patients with dyshormonogenesis suspected were submitted to intravenous perchlorate sodium test and otorhinolaryngologist and tonal audiometric evaluation, if necessary. RESULTS: We evaluated 28 female and 12 male after levothyroxine treatment off for 4 weeks. Mean age of studied patients was 6.5 years-old. Mean TSH was 129.9 UI/mL (normal: 0.7-6.0). T3, T4 and freeT4 ranged from 14 217 ng/dL (normal 105-269) , <1.6 15.8 g/dL (normal: 1.5- 15) and < 0.3 2.7 ng/dL (normal: 0.7-1.5) respectively. TG level ranged from < 1 287 ng/dL (normal 1.7-35). CDUS showed normally located thyroid in 21 patients (53%), ectopy in 8 patients (20%), and athyrosis in 11 patients (27%). At RAIU, thyroid scan identified normal located gland in 20 patients (51%), ectopy in 13 patients (32%) e athyrosis in 7 patients (17%). Two-hours uptake was elevated in ten patients. Intravenous perchlorate sodium test was performed in 9 patients with goiter or normal volume at CDUS, with normal or elevated uptake. Only one patient presented vomit. Six patients had positive test, considering more than 20% of decline. None from these patients had neurosensorial deafness. We found discrepancy between CDUS and RAIU in 9 patients, especially in ectopic cases. Thyroglobulin measurement helped to confirm athyrosis. Highest TG levels were found in dyshormonogenesis patients due to organification defects. Therefore we determined etiologic diagnosis of ectopic gland in 32,5% of patients, hypoplasia in 20%, organification defect (TPO or THOX2 defects) in 17,5%, athyrosis in 15%, thyroglobulin defect in 7,5% and three cases were undefined (7,5%). Twenty seven patients were diagnosed with thyroid dysgenesis and had no mutation in PAX8 and TSHR genes. CONCLUSION: We established the etiologic diagnosis in 37 from 40 patients here studied. CDUS was useful on etiologic diagnosis of CH, especially associated to thyroglobulin level. Intravenous perchlorate sodium test was safe and efficient in CH differential diagnosis of dyshormonogenesis. We identified no mutation in PAX8 and TSHR genes in dysgenesis cases

Parasitic wasps are highly diverse and play a major role in suppression of herbivorous pest populations, but relatively little is known of the mechanisms driving their diversity. Molecular studies indicate that cryptic species complexes resulting from adaptations to specific hosts or host-foodplants may be common. The gregarious endoparasitoid, Cotesia congregata (Braconidae), is a model system for understanding parasitic wasp biology. It is reported to attack at least 15 species of sphingid caterpillars, most of which are plant family specialists. Molecular studies have demonstrated genetic differentiation of two host-foodplant complex sources originating from Manduca sexta on tobacco (MsT) and Ceratomia catalpae on catalpa (CcC). Response to female pheromone and elements of their courtship songs differ. Wasps from both sources mated and produced F1 hybrid offspring in the laboratory; however, 90% of hybrid females resulting from one of the reciprocal crosses failed to produce offspring. I built on this previous work by evaluating an ecological barrier, the evolution of courtship songs within the genus, and patterns of hybrid sterility among four additional host-foodplant complexes, as well as differentiation of their symbiotic bracovirus. Tests of developmental tolerance to nicotine demonstrate that MsT wasps are highly adapted to hosts feeding on tobacco, whereas CcC wasps experience high mortality. Acoustic analysis of courtship songs among host-foodplant sources of C. congregata and eleven additional species of Cotesia demonstrates that songs are species specific and appear to be correlated with genetic relatedness. Cotesia congregata from all sources mated and produced F1 hybrid offspring in the laboratory; however, hybrid females resulting from specific reciprocal crosses failed to produce progeny. Dissections of hybrid females revealed that sterile wasps lacked mature ovaries and functional bracovirus, a symbiotic virus integrated into the wasp genome and necessary to suppress the host immune system. Relative in vivo expression of wasp bracovirus genes differs between MsT and CcC host-foodplant complexes. Cumulatively, these behavioral, ecological, and genetic barriers to reproduction indicate that C. congregata is diverged into two incipient species with limited gene flow, and provides insight into the role of varied reproductive barriers in speciation of parasitic wasps.