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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Análise de polimorfismos da enzima metilenotetrahidrofolato redutase no câncer colorretal / Analysis of the methylenotetrahydrofolate reductase enzyme polymorphism in colorectal cancer

Souza, Diego Mateus de 02 February 2017 (has links)
Estudos de polimorfismos podem auxiliar na detecção de pessoas com maior risco de desenvolver câncer, caracterização de evolução diferenciada e resposta distinta ao tratamento quimioterápico ou radioterápico. O conhecimento de como estão distribuídas as frequências genotípicas é relevante quando se estuda uma população específica. Neste trabalho foi analisado os polimorfismos da enzima metilenotetrahidrofolatoredutase (MTHFR) em pacientes com Câncer Colorretal (CCR). A MTHFR tem papel importante no metabolismo do folato, metilação e síntese do DNA. A metilação do DNA desempenha um papel crítico no controle da atividade gênica. As vias de metilação e variações do gene MTHFR podem afetar o desenvolvimento do câncer e prognósticos de doenças, com isso seus efeitos precisam ser monitorados de perto no tratamento do câncer. Os genótipos variantes dos polimorfismos MTHFR677 C >T e MTHFR1298 A>C do gene da MTHFR estão associados à diminuição importante da atividade desta enzima. Este trabalho teve como objetivo verificar a frequência dos polimorfismos MTFR (677C > T e 1298A > C) em pacientes com adenocarcinomacolorretal e analisar estas frequências com os dados clinicopatológicos, incluindo-se: sexo, idade, localização tumoral, tipo histológico, antecedentes de tabagismo e alcoolismo e sobrevida dos pacientes. Duzentos e vinte cinco pacientes com o diagnóstico de adenocarcinomacolorretal, histologicamente confirmado, admitidos no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo formam o grupo caso. Utilizou-se a análise do PCR em Tempo Real para determinar os genótipos os polimorfismos através dos ensaios TaqMan ® SNP GenotypingAssay. Os resultados encontrados foram associados aos dados epidemiológicos e clinicopatológicos dos pacientes. As populações estão em equilíbrio de Hardy-Weinberg. Determinaram-se as frequências dos polimorfismos MTFR (677C > T e 1298A > C) em pacientes com adenocarcinomacolorretal onde foram levantadas e agrupadas por genótipos assim como a significância. Na análise das razões de risco de óbito por CCR na presença dos genótipos estudados não foram encontrada associações estatisticamente significativas. A curva de sobrevida comparando os genótipos no teste de Long Rank para os SNPs MTHFR 677C > T e 1298A > C não mostraram diferenças significativas na sobrevida global para pacientes com CCR. Conclui-se que as frequências dos polimorfismos MTFR (677C > T e 1298A > C) em pacientes com adenocarcinoma colorretal foram levantadas e metade dos indivíduos apresentaram frequências genotípicas de homozigotos selvagens nos dois polimorfismos estudados (CC e AA), após as associações dos polimorfismos mencionados com os dados clinicopatológicos, sexo, idade, localização tumoral, tipo histológico, antecedentes de tabagismo e alcoolismo e sobrevida não houve associações estatisticamente significativas / Polymorphism studies may help to detect people at higher risk of developing cancer, characterization of differentiated evolution, distinct response to chemotherapeutic or radiotherapeutic treatment, knowledge of how genotype frequencies are distributed becomes necessary for any work with a specific population. In this work, the polymorphisms of the enzyme methylenetetrahydrofolatoreductase (MTHFR) were analyzed in patients with Colorectal Cancer (CRC). MTHFR plays an important role in folate metabolism, methylation and DNA synthesis. DNA methylation plays a critical role in the control of gene activity. Methylation pathways and variations of the MTHFR gene may affect the development of cancer and prognosis of diseases, so their effects need to be closely monitored in the treatment of cancer. The variant genotypes of the MTHFR677 C > T and MTHFR1298 A > C polymorphisms of the MTHFR gene are associated with a significant decrease in the activity of this enzyme. The aim of this study was to verify the frequency of MTFR polymorphisms (677C > T and 1298A > C) in patients with adenocarcinomes and to analyze these frequencies with clinicopathological data, including: sex, age, tumor location, histological type, history of smoking and alcoholism and patient survival. Two hundred and twenty five patients with the diagnosis of histologically confirmed adenocarcinomes were admitted to the Hospital das Clínicas of the Faculty of Medicine of the University of São Paulo, forming the case group. Real-time PCR analysis was used to determine the genotype polymorphisms through the TaqMan ® SNP Genotyping Assay assays. The results were associated with the epidemiological and clinicopathological data of the patients. The populations are in Hardy-Weinberg equilibrium. The frequencies of the MTFR polymorphisms (677C > T and 1298A > C) were determined in patients with adenocarcinoma-choroid where they were raised and grouped by genotypes as well as significance. The analysis of death risk ratios by RCC in the presence of the studied genotypes, there was no statistically significant associations were found. The survival curve comparing the genotypes in the Long Rank test for MTHFR 677C > T and 1298A > C SNPs did not show significant differences in overall survival for CRC patients. It was concluded that the frequencies of MTFR polymorphisms (677C > T and 1298A > C) in patients with colorectal adenocarcinoma were raised and half of the individuals presented genotype frequencies of wild homozygotes in the two polymorphisms studied (CC and AA), after associations of polymorphisms mentioned, there was no statistically significant association between these polymorphisms and the variables studied: sex, age, tumor location, histological type, history of smoking and alcoholism and survival
72

Impacto da expressão do gene PNPLA3 na esteatose hepática em pacientes com infecção pelo vírus da hepatite C / Impact of PNPLA3 gene expression in hepatic steatosis in patients infected with hepatitis C virus

Manchiero, Caroline 02 February 2017 (has links)
Introdução: O vírus da hepatite C (HCV) possui distribuição mundial, ocorrendo em indivíduos de todas as idades e etnias. Cerca de 80% dos casos de hepatite C aguda progridem para infecção crônica e 10-20% desses casos desenvolverão complicações de doença hepática crônica, como cirrose hepática, dentro de duas a três décadas e 1-5% vão desenvolver câncer de fígado. Estudos indicam que o polimorfismo rs738409 do gene PNPLA3 pode estar relacionado ao desenvolvimento da esteatose hepática e à progressão da fibrose. O presente estudo avaliou a associação entre o polimorfismo rs738409 presente no gene da PNPLA3 e presença de esteatose e o grau de fibrose em pacientes com hepatite C crônica. Métodos: Foram selecionados 314 pacientes com hepatite C crônica atendidos no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Foi realizada a genotipagem do polimorfismo rs738409 (I149M) do gene PNPLA3, utilizando a técnica de reação em cadeia da polimerase - análise de tamanho de fragmentos de restrição (PCR-RFLP). Resultados: Dos pacientes incluídos no estudo, 133 (45,9%) apresentaram o genótipo CC, 63 (21,7%) o genótipo CG e 94 (32,4%) o genótipo GG. Idade, infecção pelo vírus da hepatite C genótipo 3, moderada ou alta atividade inflamatória (A2-A3), IMC elevado, nível elevado de GGT e presença do alelo G (GG ou GC) mantiveram-se associados à esteatose hepática na análise multivariada. Permaneceram associados à fibrose avançada: idade, sexo masculino, níveis elevados de AST e GGT, moderada ou alta atividade inflamatória (A2-A3) e presença de esteatose hepática ( > 5%) na análise multivariada. Conclusões: Observou-se associação entre o polimorfismo rs738409 do gene PNPLA3 e esteatose hepática nos pacientes com hepatite C crônica, mas essa associação não foi encontrada com fibrose avançada / Introduction: The hepatitis C virus (HCV) has a worldwide distribution, occurring in individuals of all ages and ethnicities. About 80% of acute hepatitis C cases progress to chronic infection and 10-20% of these cases will develop the complications of chronic liver disease such as liver cirrhosis, within 2 to 3 decades, and 1-5% will develop liver cancer. Studies indicate that the rs738409 polymorphism of the PNPLA3 gene may be related to the development of hepatic steatosis and fibrosis progression. The present study evaluated the association between the rs738409 polymorphism present in the PNPLA3 gene and the presence of steatosis and the degree of fibrosis in patients with chronic hepatitis C. Methods: Three hundred and fourteen patients with chronic hepatitis C assisted at the Clinical Hospital of the Medical School of the University of São Paulo were selected. Genotyping for the PNPLA3 rs738409 (I149M) polymorphism was performed by a polymerase chain reactionrestriction fragment length polymorphism assay (PCR-RFLP). Results: Of the patients included in the study, 133 (45.9%) had the CC genotype, 63 (21.7%) the CG genotype and 94 (32.4%) the GG genotype. The multivariate analysis showed an association between hepatic steatosis and age, infection with hepatitis C genotype 3, moderate or high inflammatory activity (A2-A3), high BMI, high level of GGT and presence of the G allele (GG or GC). Furthermore, multivariate analysis also showed an association between advanced fibrosis and male gender, high levels of AST and GGT, moderate or high inflammatory activity (A2-A3) and the presence of hepatic steatosis ( > 5%). Conclusions: It was observed an association between PNPLA3 rs738409 polymorphism and hepatic steatosis in patients with chronic hepatitis C but this association was not found with advanced fibrosis
73

Associação dos polimorfismos nos genes CYBA e NOX4 da NADPH oxidase e sua relação com síndrome metabólica na doença hepática gordurosa não alcoólica (DHGNA) / Association of polymorphisms in CYBA and NOX4 genes of NADPH oxidase and its relation with metabolic syndrome and non-alcoholic fatty liver disease (NAFLD)

Rabelo, Fabíola 02 February 2018 (has links)
Introdução e Objetivos: A Doença hepática gordurosa não alcóolica (DHGNA) é claramente marcada por influência ambiental, no entanto, fatores genéticos têm sido associados a progressão para formas mais graves de DHGNA. O estresse oxidativo tem sido cada vez mais enfatizado nesta evolução e o sistema NADPH parece ser uma importante fonte de produção de espécies reativas de oxigênio. O papel dos polimorfismos do sistema NADPH nessa população e sua possível relação com progressão de doença e síndrome metabólica são desconhecidos. Desta maneira, investigamos dois polimorfismos de nucleotídeo único (SNPs) na região reguladora dos genes que codificam a NADPH oxidase 4 subunidade catalítica (NOX4) e sua subunidade regulatória p22phox (CYBA) e sua relação com variáveis histológicas e bioquímicas em pacientes com DHGNA. Métodos: 207 pacientes com DHGNA com biópsia hepática (esteatose=27; esteato-hepatite=180), sendo (70% do sexo feminino), foram genotipados para SNPs da Nox4 (rs3017887) e CYBA -675 T/A. O DNA genômico foi extraído a partir de células do sangue periférico e a genotipagem foi realizada utilizando primers específicos e sondas fluorescentes marcadas por sequenciamento. A análise histológica foi baseada na classificação de Kleiner et al (2005). Todos os pacientes eram negativos para os marcadores de hepatites virais, doença de Wilson, hemocromatose, doenças auto-imunes e tinham ingestão diária de álcool < 100 g/semana. Resultados:Associação do CYBA -675 T/A com triglicerídeos foi observada: 176,87 ± 12,93 (TT) versus 228,70 ± 21,66 (XA), p = 0,007 . Quando a população é estratificada, a associação aparece apenas entre os pacientes que possuem esteatohepatite não alcoólica (EHNA). Foi observada uma associação do CYBA-675 T / A com HDL: 48,05 ± 1,71 (TT) vs 41,70 ± 2,91 (TA) vs 28,03 ± 9,47 mg / dL (AA), p = 0,001. Quando a população é estratificada, a associação aparece apenas entre os pacientes que possuem EHNA. Quando se estudou o SNP no gene da NOX4, observou-se associação com ALT (CA + AA: 60,10 ± 6,01 U/L vs CC: 44,23 ± 4,36 U/L; P = 0,02). Porém, quando a população foi estratificada em esteatose e EHNA não se verificou diferença estatisticamente significante na frequência dos genótipos. Não houve associação de SNPs de genes que codificam proteínas do sistema NADPH oxidase nos genes CYBA (não registrado) e Nox4 (rs 3017887) e a presença de EHNA, nos portadores de DHGNA. Quanto aos resultados clínicos, observou-se que os graus de fibrose mais avançados ocorreram em pacientes com diagnóstico de Diabetes Mellitus tipo 2 (66,9% vs 37,5%; p= 0,007), além de serem mais obesos (32,2% vs 29%; p=0,003). Além disso, os níveis séricos de glicose e insulina aumentaram significantemente, de acordo com a presença de EHNA. A frequência da SM foi significativamente maior em pacientes com EHNA. Conclusões: 1) Houve associação entre a presença do genótipo CC na Nox4 SNP com uma maior concentração de ALT na população em geral 2) Houve associação entre a presença do genótipo AA no polimorfismo do gene -675 T/A CYBA com uma maior concentração de TGL e menor de HDL, nos pacientes com EHNA 3) Houve associação entre a presença de síndrome metabólica e graus avançados de fibrose hepática em portadores de DHGNA. No entanto, a amostra deve ser ampliada para confirmar estas associações, bem como, para melhor explorar possíveis relações com escores de fibrose e inflamação / Background/Aims: Oxidative stress has been implicated in progression to severe forms of non-alcoholic fatty liver disease (NAFLD). NADPH oxidase appears to be an important source of production of reactive oxygen species. We investigated by the first time two single nucleotide polymorphisms (SNPs) in the regulatory region of genes encoding the NADPH oxidase 4 (NOX4) and p22phox (CYBA) in NAFLD. Methods: 207 biopsy-proven NAFLD patients (27 = steatosis; 180= NASH) were evaluated. Genomic DNA was extracted from peripheral blood cells and on Nox4 and CYBA polymorphisms were determined by direct sequencing of PCR. All the patients were negative for markers of viral hepatitis, Metabolic diseases, autoimmune diseases and had daily intake of alcohol < 100 g/week. Results: An association of CYBA -675 T / A with triglycerides was observed: 176.87 ± 12.93 (TT) versus 228.70 ± 21.66 (XA), mean ± SEM, p = 0.007. When the population is stratified, the association appears only among patients who have non-alcoholic steatohepatitis (NASH). An association of CYBA-675 T/A with HDL was observed: 48.05 ± 1.71 (TT) vs 41.70 ± 2.91 (TA) vs 28.03 ± 9.47 mg/dL (AA), mean ± SEM, p = 0.001. When the population is stratified, the association appears only among patients who have NASH. When the NOX4 (rs 3017887) gene was studied, there was association with ALT (CA + AA: 60.10 ± 6.01 U / L vs CC: 44.23 ± 4.36 U/L; P = 0, 02). However, when the population was stratified in steatosis and NASH, there was no statistically significant difference in the frequency of genotypes. There was no association of SNPs from genes encoding NADPH oxidase system proteins in the CYBA (unregistered) and Nox4 (rs 3017887) genes and the presence of NASH in the DHGNA carriers. Regarding the clinical results, it was observed that the most advanced degrees of fibrosis occurred in patients diagnosed with Type 2 Diabetes Mellitus (66.9% vs 37.5%, p = 0.007), in addition to being more obese (32.2% % vs 29%, p = 0.003). In addition, serum glucose and insulin levels increased significantly, according to the presence of NASH. The frequency of MS was significantly higher in patients with NASH. Conclusions: 1) There was an association between the presence of the CC genotype in the Nox4 SNP with a higher concentration of ALT in the general population. 2) There was an association between the presence of the AA genotype in the CYBA gene -675 T / A polymorphism with a higher concentration of TGL and lower HDL in patients with NASH. 3) There was an association between the presence of metabolic syndrome and advanced degrees of hepatic fibrosis in patients with NAFLD. However, the sample should be expanded to confirm these associations, as well as to better explore possible relationships with fibrosis and inflammation scores
74

Influência do transplante renal e de polimorfismos genéticos nos níveis de proteína C reativa em pacientes com doença renal crônica / Influence of kidney transplantation and single-nucleotide polymorphisms on C - reactive protein levels in chronic kidney disease patients

Silva Junior, Antonio Carlos Cordeiro 21 January 2008 (has links)
Avaliamos a influência do transplante renal (Tx) e de \"polimorfismos de nucleotídeos isolados\" (SNPs), na região promotora do gen codificador da proteína C reativa, sob os níveis de PCR, em 50 pacientes com doença renal crônica em terapia dialítica. Os níveis de PCR foram avaliados no período pré-Tx, no primeiro e segundo anos pós-Tx. Inicialmente, os pacientes foram divididos em três grupos de acordo com os percentis (25, 50 e 75) dos níveis de PCR no período pré-Tx. Em seguida, avaliamos os genótipos para 2 SNPs, um bi-alélico na posição -409 (G->A) e um tri-alélico (C->T->A) na posição -390. Na análise geral os níveis de PCR decresceram significativamente no primeiro ano pós-Tx e tiveram uma elevação, não significativa, no segundo ano após o transplante. Após a divisão por percentis, observamos que nos pacientes cujos níveis de PCR se situavam dentro da normalidade (percentis 25 e 50), este marcador se manteve estável ao longo do estudo, enquanto houve uma significativa e progressiva redução dos níveis de PCR, pós-Tx, nos pacientes do percentil 75 (p=0,002). Todos os pacientes apresentaram o genótipo -409GG, quando avaliados para o SNP nesta posição. Quando avaliados para a posição -390, não foram encontrados pacientes com o alelo \"A\", havendo 15 pacientes com o genótipo \"CC\", 11 \"TT\" e 24 \"CT\". A média geral dos níveis de PCR diferiu significativamente entre os indivíduos de diferentes genótipos (p=0,019). A presença do alelo \"T\" associou-se a níveis mais elevados de PCR no pré-transplante (p=0,007) e no primeiro ano pós (p=0,001), fato não observado no segundo ano (p=0,146). Concluímos que o Tx reduz os níveis de PCR em pacientes com PCR previamente elevada. SNPs na posição -390 da região promotora do gen codificador da PCR influenciam os níveis basais desta proteína, de tal forma que o alelo \"C\" se associa com os menores níveis de PCR e o alelo \"T\" com os maiores. Em nossos pacientes, esta influência deixou de ser observada no segundo ano pós-Tx. / We evaluated the influence of kidney transplantation (Tx), as well as single nucleotide polymorphisms (SNPs) in the \"C\" reactive protein (CRP) gene promoter region on CRP levels in 50 patients with chronic kidney disease under dialysis. CPR levels were evaluated at pre-Tx, as well as during the first and second years post-Tx. Initially, patients were divided into tree groups according to pre-Tx CRP percentiles (25, 50 and 75). At the same time, we evaluated the genotypes for 2 SNPs, a bi-allelic (G->A) at the -409 position and a tri-allelic (C->T->A) at the -390 position. In general analysis, CRP levels was significantly reduced in the first year and increased, not significantly, in the second year post Tx. Upon dividing the groups, the patients with CRP levels under the normal range (25th and 50th percentiles) presented stable, whereas there was a progressive and significant reduction in the post Tx CRP levels in patients in the 75th percentile (p=0.002). All patients presented the -409GG genotype. When evaluated for the -390 position, the \"A\" allele was not found and there were 15 \"CC\" pts, 11 \"TT\" and 24 \"CT\". CRP general means were different among patients with different genotypes (p=0.019). Also, allele \"T\" presence was associated with higher CRP levels in the pre-Tx (p=0.007) and first year post (p=0.001), but not at the second year post-Tx (p=0.146). We concluded that Tx reduces CRP levels in patients with previously high CRP. SNPs at the -390 position of the CRP gene promoter region influence CRP´s basal levels in such a way that the \"C\" allele correlates with the lowest and the \"T\" with the highest. We did not observe this influence in our patients at the second year post-Tx.
75

Genetic association study in candidate genes and pathogenesis of hepatocellular carcinoma in Chinese.

January 2003 (has links)
by Sung Ying-Man, Mandy. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 112-125). / Abstracts in English and Chinese. / Acknowledgments --- p.I / List of Abbreviations --- p.II / Abstract --- p.IV / 摘要 --- p.VII / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Epidemiology --- p.1 / Chapter 1.2 --- Aetiological factors --- p.4 / Chapter 1.2.1 --- Hepatitis B infection --- p.4 / Chapter 1.2.2 --- Aflatoxin exposure --- p.5 / Chapter 1.2.3 --- Alcohol consumption --- p.5 / Chapter 1.2.4 --- Genetic risk factors --- p.6 / Chapter 1.3 --- Aims of the study --- p.7 / Chapter Chapter 2 --- Polymorphisms of candidate genes in Interleukin- signalling pathway in HCC --- p.6 / Chapter 2.1 --- Introduction --- p.9 / Chapter 2.2 --- Materials and Methods --- p.15 / Samples and Genomic DNA isolation --- p.15 / PCR-PFLP --- p.15 / dHPLC --- p.16 / Direct Sequencing --- p.17 / Stattistical Analysis --- p.17 / Chapter 2.3 --- Results --- p.25 / Chapter 2.3.1 --- Known IL6 polymorphisms --- p.25 / Chapter 2.3.2 --- IL-6R and gp130 polymorphisms --- p.28 / Chapter 2.3.3 --- Stat-3 polymorphisms --- p.29 / Chapter 2.3.4 --- SOCS-1 polymophisms --- p.32 / Chapter 2.3.5 --- Mutation screening of IL-6 gene --- p.34 / Chapter 2.3.6 --- Mutation screening of SOCS-1 gene --- p.39 / Chapter 2.4 --- Discussion --- p.40 / Chapter 2.4.1 --- Interleukin-6 --- p.40 / Chapter 2.4.2 --- Gp130 and IL6-R --- p.43 / Chapter 2.4.3 --- STAT-3 --- p.44 / Chapter 2.4.4 --- SOCS-l --- p.46 / Chapter Chapter 3 --- Methylation status of SOCS-1 gene in Chinese HCC patients / Chapter 3.1 --- Introduction --- p.49 / Chapter 3.2 --- Methods and Materials --- p.53 / Tissue Sampling --- p.53 / Methylation specific PCR (MSP) --- p.53 / Chapter 3.3 --- Results --- p.55 / Chapter 3.4 --- Discussion --- p.56 / Chapter Chapter 4 --- Polymorphisms of enzyme encoding genesin steroidogenesis in Chinese / Chapter 4.1 --- Introduction --- p.59 / Chapter 4.1.1 --- Steroid 5a reductases (SRD5A) --- p.62 / Chapter 4.1.1a --- Steroid 5a reductase type II (SRD5A2) --- p.63 / Chapter 4.1.1b --- Steroid 5a reductase type I (SRD5A1) --- p.65 / Chapter 4.1.2 --- Cytochrome P450al7 (CYP17) --- p.67 / Chapter 4.1.3 --- "Cytochrome P450, family 1,subfamily A polypeptide1 (CYP1A1)" --- p.69 / Chapter 4.1.4 --- "Cytochrome P450, subfamily IIIA (niphedipine oxidase) polypeptide 4 (CYP3A4)" --- p.71 / Chapter 4.2 --- Materials and Methods --- p.74 / Samples and Genomic DNA isolation --- p.74 / PCR-PFLP --- p.74 / Direct Sequencing --- p.74 / Statistical Analysis --- p.74 / Chapter 4.3 --- Results --- p.77 / Chapter 4.3.1 --- SRD5A2 --- p.77 / Chapter 4.3.2 --- Linkage Disequilibrium in SRD5A2 gene --- p.83 / Chapter 4.3.2 --- SRD5A1 --- p.84 / Chapter 4.3.3 --- CYP17 --- p.87 / Chapter 4.3.4 --- CYP1A1 --- p.89 / Chapter 4.3.5 --- CYP3A4 --- p.92 / Chapter 4.3.6 --- Logistic regression --- p.95 / Chapter 4.4 --- Discussion --- p.96 / Chapter 4.4.1 --- SRD5A2 --- p.96 / Chapter 4.4.2 --- SRD5A1 --- p.99 / Chapter 4.4.3 --- CYP17 --- p.101 / Chapter 4.4.4 --- CYP1A1 --- p.103 / Chapter 4.4.5 --- CYP3A4 --- p.106 / Chapter 4.4.6 --- Logistic Regression --- p.107 / Chapter Chapter 5 --- Conclusions and Future Prospect --- p.108 / Chapter 5.1 --- Conclusions --- p.108 / Chapter 5.2 --- Future works and prospect --- p.111 / References --- p.113
76

Associação entre fatores genéticos e risco aumentado de prematuridade em pacientes com antecedente de incompetência cervical / Association between genetic factors and high risk of prematurity in women with cervical insufficiency

Ana Paula Vieira Dias Alves 08 June 2016 (has links)
A incompetência istmo cervical é uma importante causa de prematuridade. Atualmente, o componente genético está relacionado ao parto prematuro, dentre os quais os polimorfismos de nucleotídeo único (SNPs) de alguns genes candidatos estão associados. Os SNPs nos genes do colágeno, da matrix extracelular e das de interleucinas têm relação direta com o comprimento do colo uterino podendo relacionar-se com o encurtamento do colo uterino, como também ocorre na incompetência cervical. Este estudo tem o objetivo de associar a frequência dos SNPs dos genes do COL1 A1, COL 4A3, TGF-B e TIMP2 à história de incompetência cervical. Foi realizado estudo de caso controle com grupo de pacientes, que realizaram cerclagem do colo uterino na última gestação e o grupo de pacientes com antecedente de gestação a termo (controle). Em sangue periférico, foi extraído DNA, realizadas reações de PCR com primers específicos para os SNPs de interesse em 62 amostras preparadas para sequenciamento de última geração pelo Ion Torrent. Houve leitura satisfatória em 57 amostras, sendo 28 casos e 29 controles. A frequência do SNPS do COL1A1 no grupo caso foi de 70,4% versus 33,3% no grupo controle (p=0,03). Os SNPs do COL4A3 e do TIMP2 apresentaram associação com o antecedente de abortos totais (p=0,02 e p=0,023) e abortos tardios (p=0,001 e p=0,034); para os demais SNPs não houve diferença em frequência entre os grupos caso e controle. Foram identificados SNPs exônicos ainda não descritos na literatura. O presente estudo observou uma maior taxa de homozigoze T/T para o SNP COL1A1 no grupo caso, que é um gene associado ao metabolismo do colágeno, além de identificar SNPs ainda não descritos na literatura, que poderão ser objeto de estudo no futuro para conhecimento da sua repercussão na composição do colágeno / Cervical incompetence is one of the most important causes of prematurity. It has already been suggested that genetic factors plays a significant hole in determining the risk of preterm birth and the single nucleotide polimofisms (SNPS) from candidate genes are associated. Polymorfisms in several genes such as the collagen, the extracelular matrix and the interleucins, are related to abnormal cervical length, as it occurs in cervical incompetence. The aim of this study, was to associate the frequency of the SNPs in the COL1A1, COL4A3, TGF-B and TIMP2 genes to the cervical incompetence. We conduced a case control study with patients submitted to cervical cerclage and a control group with women who delivery at term. DNA was isolated from blood samples and amplifications of the genomic DNA were performed by PCR protocol with specific primers for the SNPs. DNA sequencing of 62 samples, was obtained from next generation sequencing on the Ion Torrent. A total of 57 samples, including 28 cases and 29 controls had results available. The frequency of the SNP in COL1A1 in the case group was 70,4% versus 33% in the control group (p=0,03). The SNPS in COL4A3 and TIMP2 were significant related to the history of miscarriages (p=0,2 and p=0,023) and fetal losses (p=0,001 and p=0,034) No significant differences were observed in the frequencies for the others SNPs in the two groups. In the present study, non described exonic SNPs were discovered. Higher frequencies of the homozygous T/T genotype in COL1A1 were observed in the case group involving the collagen metabolism and the non described exonic SNPs might be associated to collagen abnormalities in future studies
77

Polimorfismos do gene BMP4 em pacientes com a síndrome dos ovários policísticos / Polimorphisms of BMP4 gene in patients with polycystic ovary syndrome

Daniella De Grande Curi 02 December 2014 (has links)
A síndrome dos ovários policísticos (SOP) é um distúrbio endócrino complexo e heterogêneo, caracterizado por hiperandrogenismo e anovulação crônica. Dentre as manifestações clínicas do hiperandrogenismo, o hirsutismo é o mais frequente e pode estar presente em cerca de 70% das pacientes com SOP. Sabe-se que o crescimento e diferenciação do pelo são regulados por fatores locais, endócrinos, parácrinos e genéticos. No entanto, a fisiopatologia do hirsutismo ainda é pouco conhecida. O gene BMP4 (que codifica a Proteína Morfogenética Óssea-4) relaciona-se ao controle do crescimento e diferenciação do pelo, porém não há estudos sobre seu papel no hirsutismo em mulheres com síndrome dos ovários policísticos. Foram estudadas 245 mulheres, 142 SOP e 103 controles em que analisaram-se os polimorfismos rs4898820 e 538 T/C, para verificar frequências genotípicas e alélicas. Nas pacientes com SOP foi investigada a existência de associação entre esses polimorfismos e hirsutismo e parâmetros laboratoriais e clínicos. Não houve diferença significante na frequência dos polimorfismos entre os grupos. Não houve associação dos polimorfismos com hirsutismo. Quando analisados os exames laboratoriais das mulheres com SOP, houve associação do genótipo mutado do polimorfismo 538 T/C (CC) com níveis mais altos de SHBG, menores de glicemia e maior sensibilidade à insulina. Houve também associação entre os alelos mutados (CC ou TC), com menores níveis de testosterona livre. Encontrou-se diferença significante para o FSH nas portadoras do genótipo mutado para o polimorfismo rs4898820 (TT). Não houve associação dos polimorfismos com hirsutismo / Polycystic ovary syndrome (PCOS) is a complex and heterogeneous endocrine disorder characterized by chronic anovulation and hiperandrogesnism. Among the clinical manifestations of hyperandrogenism, hirsutism is the most frequent and may be present in approximately 70% of patients with PCOS. It is known that the hair growth and differentiation are coordinated by local, endocrine, paracrine and genetic factors. However, the pathophysiology of hirsutism is poorly understood. BMP-4 (Bone Morphogenetic Protein-4) is a gene involved in the hair growth and differentiation, but there are no studies about its action in hirsutism in women with polycystic ovary syndrome. A total of 245 women, 142 with PCOS diagnostic and 103 control women were studied to investigate the the allelic frequency of the single nucleotide polymorfisms rs4898820 and 538 T/C in PCOS in comparison with the control group. In PCOS group, we sought to investigate a possible association between the genetic variations and the hirsutism. There were no differences for the polymorphisms between groups. There was no association between the genotypes and the presence of hirsutism in PCOS women. When the polymorphisms were analyzed in the PCOS group, those who had homozygous genotype for 538 T/C (CC) had lower levels of SHBG, lower levels of glucose and better insulin sensitivity. Mutated allele (CC or TC), were associated with lower levels of free testosterone. Those who had the mutated genotype for the polymorphism rs4898820 (TT) had higher levels of FSH
78

Identify SNPs associated with type 2 diabetes using self-organizing maps and random forests.

January 2009 (has links)
Zhang, Ji. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 100-104). / Abstracts in English and Chinese. / Chapter CHAPTER 1. --- Introduction / Chapter 1.1. --- Introduction of genetic association studies --- p.1 / Chapter 1.1.1. --- Application of genetic association studies in complex diseases --- p.3 / Chapter 1.1.2. --- Application of genetic association studies in type-2 diabetes --- p.4 / Chapter 1.2. --- Study design of genetic association studies --- p.7 / Chapter 1.3. --- Overview of statistical approaches in association studies --- p.10 / Chapter 1.3.1. --- Preliminary analyses --- p.10 / Chapter 1.3.1.1. --- HardýؤWeinberg equilibrium testing --- p.10 / Chapter 1.3.1.2. --- Inference of missing genotype data --- p.12 / Chapter 1.3.1.3. --- SNP tagging --- p.14 / Chapter 1.3.2. --- Single-point and multipoint tests for association --- p.15 / Chapter 1.4. --- Other relevant methods employed in this study --- p.20 / Chapter 1.4.1. --- Self-Organizing Maps (SOM) with further classification by K-means clustering --- p.20 / Chapter 1.4.2. --- Random forests --- p.27 / Chapter 1.5. --- Main objectives of this study --- p.31 / Chapter CHAPTER 2. --- Materials and methods / Chapter 2.1. --- Study cohort --- p.32 / Chapter 2.2. --- Study design --- p.34 / Chapter 2.2.1. --- Construction of sample sets for each stage using SOM and K-means clustering --- p.34 / Chapter 2.2.2. --- Stage 1 analysis by random forests --- p.37 / Chapter 2.2.3. --- Stage 2 analysis by chi-square test --- p.42 / Chapter 2.2.4. --- Two-stage genetic association study by chi-square test --- p.43 / Chapter 2.2.5. --- Comparison of results: random forests plus chi-square test versus chi-square test --- p.43 / Chapter 2.2.6. --- Validation of results in the whole sample set by allelic chi-square test --- p.44 / Chapter 2.2.7. --- Extensions of the study: cumulative effects of candidate SNPs on risk of type-2 diabetes --- p.45 / Chapter CHAPTER 3. --- Results / Chapter 3.1. --- Effects of sample classification by SOM and K-means clustering --- p.50 / Chapter 3.2. --- Genetic associations in stage 1 --- p.64 / Chapter 3.3. --- Genetic associations in stage 2 and validation of results --- p.69 / Chapter 3.4. --- Cumulative effects of candidate SNPs on risk of type-2 diabetes --- p.76 / Chapter CHAPTER 4. --- Discussion / Chapter 4.1. --- Overall strategy --- p.81 / Chapter 4.1.1. --- Effects of SOM and K-means clustering --- p.82 / Chapter 4.1.2. --- Effects of random forests in the first stage of association study --- p.83 / Chapter 4.1.3. --- Comparison of our method with traditional chi-square test --- p.84 / Chapter 4.1.4. --- Joint effects of candidate SNPs selected by the hybrid method --- p.86 / Chapter 4.2. --- Biological significance of candidate SNPs --- p.88 / Chapter 4.2.1. --- Gene CDKAL1 --- p.89 / Chapter 4.2.2. --- Gene KIAA1305 --- p.90 / Chapter 4.2.3. --- Gene DACH1 --- p.91 / Chapter 4.2.4. --- Gene FUCA1 --- p.92 / Chapter 4.2.5. --- Gene KCNQ1 --- p.93 / Chapter 4.2.6. --- Gene SLC27A1 --- p.94 / Chapter 4.3. --- Limits and improvement of this study --- p.96 / Chapter 4.4. --- Conclusion --- p.99 / REFERENCES --- p.100
79

The influences of indoor environmental factors and CD14 polymorphisms on asthma phenotypes in Chinese children.

January 2007 (has links)
Wong, Yun Sze. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 142-162). / Abstracts in English and Chinese. / Abstract (in English) --- p.ii / Abstract (in Chinese) --- p.vi / Acknowledgement --- p.ix / Statement of Work --- p.x / Table of Contents --- p.xi / List of Tables --- p.xiv / List of Figures --- p.xvi / Glossary of Terms and Abbreviations --- p.xviii / Chapter Section I: --- Introduction --- p.1 / Chapter Chapter 1: --- General Overview of Asthma --- p.2 / Chapter 1.1 --- Asthma definition and its phenotype --- p.2 / Chapter 1.2 --- Asthma epidemiology and its prevalence in past decades --- p.4 / Chapter 1.3 --- Hygiene hypothesis and asthma development --- p.8 / Chapter 1.4 --- Asthma pathogenesis and innate immunity --- p.12 / Chapter 1.5 --- The environmental factors and genetic makeup in relation with asthma --- p.17 / Chapter Chapter 2: --- Study Plan and Obj ective --- p.21 / Chapter Section II: --- Literature Review --- p.24 / Chapter Chapter 3: --- Indoor Environmental factors of Asthma --- p.25 / Chapter 3.1 --- Overview of the indoor environmental factors --- p.25 / Chapter 3.2 --- House dust endotoxin --- p.27 / Chapter 3.2.1 --- Determinants of endotoxin exposure in home environment --- p.21 / Chapter 3.2.2 --- Protective role of endotoxin in allergy and asthma development --- p.29 / Chapter 3.2.3 --- Deleterious effect of endotoxin exposure in asthma: the dark side --- p.31 / Chapter 3.3 --- Allergen --- p.34 / Chapter 3.3.1 --- Allergens: an update --- p.34 / Chapter 3.3.2 --- Determinants of allergens in home environment --- p.35 / Chapter 3.3.3 --- Allergens avoidance: environmental intervention --- p.36 / Chapter 3.4 --- Nitrogen dioxide --- p.40 / Chapter 3.4.1 --- Determinants of indoor nitrogen dioxide and its relation with gas cooking --- p.40 / Chapter 3.4.2 --- The adverse effects of nitrogen dioxide on respiratory symptoms --- p.41 / Chapter 3.4.3 --- Reactive nitrogen species and nitrosative stress in asthma --- p.42 / Chapter Chapter 4: --- CD14 Single Nucleotide Polymorphisms and Asthma --- p.45 / Chapter 4.1 --- Overview of CD14 receptor --- p.45 / Chapter 4.2 --- Action of CD14 receptor in endotoxin response --- p.47 / Chapter 4.3 --- Relation of CD14 with asthma --- p.48 / Chapter 4.3.1 --- Associations between CD14 polymorphisms and asthma phenotypes --- p.48 / Chapter 4.3.2 --- Endotoxin switch concept: from gene to gene - environment --- p.52 / Chapter Section III: --- Study Core --- p.55 / Chapter Chapter 5: --- Methodology in indoor environment investigation and its result --- p.57 / Chapter 5.1 --- Study Population --- p.57 / Chapter 5.2 --- Home Visiting Protocol --- p.60 / Chapter 5.2.1 --- The International Study of Asthma and Allergies in Childhood (ISAAC) --- p.60 / Chapter 5.2.2 --- ISAAC questionnaire --- p.61 / Chapter 5.2.3 --- House dust collection procedures --- p.62 / Chapter 5.2.4 --- Indoor nitrogen dioxide measurements --- p.65 / Chapter 5.2.4.1 --- Ogawa passive sampler --- p.65 / Chapter 5.2.4.2 --- Preparation and measurement procedures --- p.66 / Chapter 5.2.4.3 --- Indoor nitrogen dioxide quantification --- p.67 / Chapter 5.3 --- House dust extraction --- p.69 / Chapter 5.4 --- House dust endotoxin measurement --- p.70 / Chapter 5.5 --- Allergen measurement --- p.72 / Chapter 5.6 --- Statistical Analysis --- p.75 / Chapter 5.7 --- Results --- p.77 / Chapter 5.7.1 --- Demographic data and subjects characteristics --- p.77 / Chapter 5.7.2 --- "Dust weight, endotoxin and allergen levels and their determinants in household" --- p.82 / Chapter 5.7.3 --- Indoor NO〕2levels and its determinant in household --- p.95 / Chapter 5.7.4 --- Associations between indoor environmental factors and respiratory health --- p.96 / Chapter 5.7.4.1 --- Clinical symptoms --- p.96 / Chapter 5.7.4.2 --- Exhaled NO levels --- p.101 / Chapter 5.7.4.3 --- Spirometric indices --- p.103 / Chapter Chapter 6: --- Methodology in genotyping CD14 polymorphisms and its result --- p.105 / Chapter 6.1 --- Study population --- p.105 / Chapter 6.2 --- Serum Total and allergen-specific IgE measurement --- p.106 / Chapter 6.3 --- CD14 Genotyping s --- p.107 / Chapter 6.3.1 --- Genotyping promoter SNPs ofCD14/-159 and -1359 --- p.107 / Chapter 6.3.2 --- Genotyping promoter SNP of CD14/-1619 --- p.109 / Chapter 6.3.3 --- Validation of genotyping by sequencing --- p.111 / Chapter 6.4 --- Statistical Analysis --- p.112 / Chapter 6.5 --- Results --- p.113 / Chapter 6.5.1 --- Subjects characteristics and clinical features. --- p.113 / Chapter 6.5.2 --- Associations between CD14 SNPs and asthma phenotypes --- p.114 / Chapter Chapter 7: --- Discussion --- p.120 / Chapter 7.1 --- Influence of indoor factors on asthmatic children --- p.120 / Chapter 7.2 --- CD14 polymorphisms in modifying asthma phenotypes --- p.135 / Chapter Chapter 8: --- Conclusion and Further Works --- p.138 / References --- p.141 / Appendix 1 Questionnaire / Appendix 2 Publications
80

Estudo da associação de genes de pigmentação com cor da pele, cabelo e olhos para fenotipagem forense em amostra brasileira / Association study of pigmentation genes with skin, hair and eyes color for forensic phenotyping purposes in Brazilian sample

Lima, Felícia de Araujo 04 May 2017 (has links)
A pigmentação humana é uma característica variável e complexa determinada por fatores genéticos e hormonais, exposição à radiação ultravioleta, idade, doenças, entre outros. Alguns polimorfismos em genes de pigmentação têm sido associados com a diversidade fenotípica de cor da pele, cabelo e olhos e em populações homogêneas. A técnica denominada Fenotipagem Forense pelo DNA (FDP) vem beneficiando a ciência forense em vários países e auxiliando investigações criminais por ser capaz de sugerir, com boa precisão, os possíveis fenótipos para as características externamente visíveis (EVCs) em amostras de origem desconhecida. No presente trabalho foram avaliadas as associações entre os SNPs presentes nos genes SLC24A5 (rs1426654; rs16960620; rs2555364), TYR (rs1126809) e ASIP (rs6058017) com cor de pele, cabelo e olhos em indivíduos da população brasileira para apontar o possível uso desses marcadores na prática forense em populações miscigenadas. Os voluntários responderam um questionário no qual fizeram a autodeclaração dessas características e estes dados foram usados para as comparações entre genótipos e fenótipos. Os resultados mostraram que para os SNPs rs2555364 e rs1426654 o alelo ancestral esteve associado com as características cor de pele negra, cabelos castanhos ou pretos e olhos castanhos. Além disso, o alelo ancestral do SNP rs6058017 foi significativamente associado com cor de pele negra e olhos castanhos. Inversamente, os alelos variantes destes SNPs são correlacionados com características de pigmentação clara para as EVCs avaliadas, corroborando os estudos prévios realizados em diferentes populações. Esses resultados mostram que a informação molecular pode ser útil para a inferência de EVCs, e a técnica de FDP é uma importante ferramenta para estudos forenses em amostra brasileira / Human pigmentation is a variable and complex trait determined by genetic and hormonal factors, exposure to ultraviolet radiation, age, diseases, among others. Some polymorphisms in pigmentation genes have been associated with the phenotypic diversity of skin, hair and eyes color in homogeneous populations. Forensic DNA Phenotyping (FDP) is benefiting forensic science in several countries, helping in criminal investigations due to its ability to suggest, with good accuracy, the possible phenotypes for externally visible characteristics (EVCs) in samples of unknown origin. Herein, we evaluated the associations between the SNPs present in the genes SLC24A5 (rs1426654; rs16960620; rs2555364), TYR (rs1126809) and ASIP (rs6058017) with skin, hair and eyes color in individuals of the Brazilian population in order to point out the possible use of these markers in forensic practice in admixed populations. The volunteers answered a questionnaire in which they self reported these characteristics for comparison between genotypes and phenotypes. The results showed that for the SNPs rs2555364 and rs1426654 the ancestral allele was associated with characteristics of black skin color, brown or black hair and brown eyes. In addition, the ancestral allele of the SNP rs6058017 was significantly associated with black skin color and brown eyes. Inversely, the variant alleles of these SNPs are correlated with fair pigmentation characteristics for the evaluated EVCs, corroborating the previous studies performed in different populations. These results show that molecular information may be useful for the inference of EVCs, and the FDP technique is an important tool for forensic studies in a Brazilian sample

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