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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.
101

Genetic influences on the pharmacokinetics and pharmacodynamics of statins. / CUHK electronic theses & dissertations collection

January 2011 (has links)
Clinical evidence suggested patients with lower plasma C-reactive protein (CRP) levels after statin therapy could have better clinical outcome. The last part of the study was to measure on-treatment high sensitivity CRP (hsCRP) levels among 229 Chinese patients with hyperlipidaemia undergoing treatment with simvastatin 40 mg daily. The patients were genotyped for 15 SNPs or haplotypes in 11 candidate genes that would have significant allele frequency among Chinese patients and may be linked to statin efficacy or hsCRP levels. The analysis suggested BMI is the largest single contributing factor of 15.0% of the variation in hsCRP levels, followed by plasma triglycerides levels contributing 4.7% and male gender 1.6% (all P<0.05). However comparisons of hsCRP levels among genotype groups did not reveal any significant findings, with or without adjustment with covariate genotypic or phenotypic factors. To further categorize individuals as high or medium risk, we set a threshold hsCRP level of 1 mg/L as the benchmark for evaluation. The CRPc.3872G>A SNP was related to lower risk compared to the homozygous wild-type genotype (adjusted odds ratio AOR = 0.289; P = 0.014) after adjusting for phenotypic factors of age, gender, smoking status, BMI, waist circumference, hip circumference, plasma lipid profiles, co-existing disease and co-medications. Another marginal finding included the HNF1A c.79A>C SNP (AOR = 0.575; P = 0.118). / Polymorphisms in the drug transporters are likely to be more important with hydrophilic statins such as pitavastatin, which undergoes transporter mediated distribution. The SLCO1B1 c.388A>G polymorphism in the gene encoding the uptake transporter organic anion transporting polypeptide (OATP1B1) is common in Chinese and the variant was associated with increases of 63--68% in maximum plasma concentration and 44--47% in systemic exposure of both the lactone and acid compared to wild-type subjects (P<0.05). Co-administration of pitavastatin with grapefruit juice (GFJ) resulted in a small increase of the area under the plasma concentration time curve (AVC) by 15--16% for both the acid and lactone (P<0.05). However, there was no significant effect on the drug-food interaction in relation to relevant SNPs in the enzymes and transporters examined. / The SNPs examined included those in the genes for the enzymes and transporters involved in the metabolic pathway or the distribution of simvastatin. Cytochrome P450 (CYP) enzymes are involved in hepatic and intestinal metabolism of several statins and simvastatin is known to undergo extensive metabolism via the CYP3A4/3A5 pathway. The common candidate SNPs in the CYP3A4/3A5 enzymes found in Chinese populations include CYP3A4*1G, CYP3AP1*3 and CYP3A5*3 , which are associated with altered enzyme expression and activity. However, no statistically significant relationship was found between these SNPs and a potential phenotypic marker of enzyme activity, the urinary ratio of 6beta-hydroxy-cortisol/cortisol (6beta-OHC/C) concentrations. The analysis of lipid lowering responses in relation to individual SNPs or combinations from gene-gene interactions also revealed no statistically significant findings. In the subgroup of patients with familial hypercholesterolaemia, the CYP3A4*1G, CYP3AP1*3 and CYP3A5*3 polymorphisms appeared to have a small effect on the changes in LDL-C and total cholesterol with the subjects with the CYP3A5*3 and CYP3AP1*3 variants showing less reduction and those with the CYP3A4*1G variant showing more reduction than subjects with the wild-type genotype with a tendency for a gene-dose effect. It is difficult to interpret these findings and the significance may be related to multiple testing. / The statins, or 3-hydroxymethyl-3-glutaryl coenzyme A (HMG-CoA) reductase inhibitors, act on the rate limiting step in endogenous cholesterol synthesis. Their primary action results in reduction of plasma low-density lipoprotein cholesterol (LDL-C) levels and this is thought to be the major mechanism by which they reduce cardiovascular events. There are considerable differences between subjects in both the plasma levels of the statins and in their effects on LDL-C and other lipid parameters and some of this variation appears to be related to genetic differences in the pathways of drug metabolism and distribution and in the pathways involved in lipid metabolism. / The variation in response may be related to variations in systemic or hepatic exposure to the drug, which in turn will be related to the pharmacokinetics. This is also likely to play a role in the adverse effects of myopathy and therapeutic tolerance. In a pharmacokinetic study in healthy male Chinese subjects, the common polymorphism of CYP2D6*10 was analyzed in relation to the pharmacokinetics of lovastatin and simvastatin. There was a tendency for reduced clearance of simvastatin lactone by 30% (P>0.05) in subjects with the CYP2D6*10/*10 genotype. With lovastatin, there were similar findings with 38.5--84.9% decrease in clearance which appeared to be related to enzyme activity according to genotype, with *5 carriers showing a greater decline in clearance than *10 carriers (P<0.05). / These results provide some insights into the pharmacokinetics and pharmacodynamics of statins and the pharamacogenetic relationships to candidate SNPs. Future research in this field should help to facilitate safer and more effective treatment with these commonly used medications, resulting in personalized therapy and optimal clinical benefits for patients with cardiovascular disease. / This thesis describes a study of 270 patients recruited from the outpatient clinics at the Prince of Wales Hospital who were treated with simvastatin 40 mg daily for at least 4 weeks. Their mean (+/-SD) LDL-C baseline level was 5.38+/-1.68 mmol/L and the reduction in LDL-C after simvastatin treatment was 2.81+/-0.99 mmol/L or -47.1+/-12.5%. / Mak, Wah Lun Valiant. / Adviser: Brian Tomlinson. / Source: Dissertation Abstracts International, Volume: 73-06, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 253-289). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
102

Influência dos polimorfismos do gene IL-28B na resposta à terapia com interferon peguilado e ribavirina em pacientes tratados por hepatite C crônica / Influence of IL-28B gene polymorphisms in the response to pegylated interferon and ribavirin therapy in patients with chronic hepatitis C

Martins, Luciane Lilian Cristina Patricio 19 August 2014 (has links)
Introdução: Estima-se que a infecção pelo vírus da hepatite C (VHC) acometa 3% da população global constituindo a maior causa de cirrose hepática e hepatocarcinoma. Nos pacientes infectados pelo genótipo 1 do VHC, a terapia em vida real com interferon peguilado (PEG-IFN) e ribavirina (RBV) resulta em 30% a 50% de resposta virológica sustentada (RVS). Este desfecho é determinado por fatores de associados ao VHC (carga viral, genótipo, quasispécies), características do hospedeiro (etnia, gênero, fatores genéticos, comorbidades, adesão) e fatores ligados aos medicamentos. Estudos de associação genética ampla (GWAS) têm demonstrado que a presença dos polimorfismos (SNP) no gene da interleucina 28B (IL-28B) associam-se a resposta à terapia baseada em interferon. Os SNPs rs12979860, rs8099917 e rs12980275 têm sido amplamente estudados e pacientes com o perfil favorável têm maiores chances de alcançar a RVS ou a eliminação espontânea do VHC. Objetivos: Avaliar a frequência relativa e a influência dos polimorfismos rs12979860 (C > T), rs8099917 (T > G) e rs12980275 (A > G) no gene IL-28B em brasileiros portadores de infecção crônica pelo VHC tratados com PEGIFN/ RBV em uma casuística de pacientes atendidos pelos médicos do Ambulatório de Hepatites DMIP/LIM-47 e avaliar retrospectivamente a possibilidade de predição de resposta à partir do perfil IL-28B na população estudada. Materiais e Métodos: Após aprovação ética, foram selecionados 171 pacientes com coleta retrospectiva e sistematizada das informações de interesse. O DNA destes pacientes foi purificado e foram desenhados primers e sondas específicas para a genotipagem dos SNPs através da técnica de reação em cadeia de polimerase em tempo real. Resultados: entre os SNPs selecionados na análise univariada rs12979860 e rs12980275 associaram-se com RVS (p < 0,05). rs8099917 não teve associação com RVS. Na análise multivariada apenas rs12980275 manteve associação com RVS (p < 0,05). Conclusão: Ao contrário do descrito na Literatura Internacional nos pacientes brasileiros apenas o pouco estudado SNP rs12980275 associou-se à RVS / Introduction: Currently, infection with hepatitis C virus (HCV) affects 3% of people worldwide, and is the major cause of chronic hepatitis C, liver cirrhosis and hepatocellular carcinoma. In patients infected by genotype 1 of HCV, 30%- 50% of patients achieve sustained virological response, when they are treated with pegylated interferon (PEG-IFN) and ribavirin (RBV). This outcome is determined by VHC factors (mutations, genotype, quasispecies), host factors (gender, ethnic, genetic factors, comorbidities, adherence to treatment) and factors related to drugs. Genome wide association studies (GWAS) demonstrated that the presence of polymorphisms in interleukin 28B gene (IL- 28B) are associated with response to interferon based therapy. SNPs rs12979860, rs8099917 and rs12980275 have been widely studied and patients with the favorable profile are more likely to achieve SVR. Objectives: To evaluate the relative frequency and influence of the polymorphisms rs12979860 (C > T), rs8099917 (T > G) and rs12980275 (A > G) in Brazilian patients treated for chronic hepatitis C with PEG-IFN/RBV, and to evaluate, retrospectively, the prediction of the response possibility from IL-28B profile in the selected patients. Material and Methods: It was selected 171 patients. Medical history was evaluated retrospectively. A real time polymerase chain reaction assay was realized in order to analyze the polymorphisms. Results: In univariate analysis the polymorphisms rs12979860 and rs12980275 were associated with SVR (p < 0,05). The SNP rs8099917 was not associated with SVR. Multivariate analysis revealed that only rs12980275 maintained an association with SVR (p < 0,05). Conclusion: It is described on international literature that rs12979860 is strongly associated with SVR, however in Brazilian patients only the less studied SNP rs12980275 was associated with SVR
103

Genetic association study between chitinase and atopic eczema phenotype in Chinese children.

January 2009 (has links)
Ching, Ka Wai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves [69-80]). / Abstract also in Chinese. / Abstract (in English) --- p.ii / Abstract (in Chinese) --- p.v / Acknowledgement --- p.viii / Table of Contents --- p.ix / List of Tables --- p.xii / List of Figures --- p.xiii / Glossary of Terms and Abbreviations --- p.xv / Chapter Chapter 1: --- Introduction --- p.1 / Chapter 1.1 --- Introduction of Atopic Eczema (AE) --- p.1 / Chapter 1.1.1 --- Definition and classification of AE --- p.1 / Chapter 1.1.2 --- Epidemiology --- p.3 / Chapter 1.1.2.1 --- The hygiene hypothesis --- p.5 / Chapter 1.2 --- Pathogenesis and Etiology --- p.6 / Chapter 1.2.1 --- Biphasic type-1/type-2 T-helper lymphocyte (Thl/Th2) immunological responses --- p.6 / Chapter 1.2.2 --- Nature and involvements of immunoglobin E (IgE) --- p.8 / Chapter 1.2.3 --- Microbial colonization --- p.9 / Chapter 1.2.4 --- Cytokines involvement --- p.10 / Chapter 1.2.5 --- Pruritus inducing neurotrophic factors --- p.11 / Chapter 1.2.6 --- "Food allergens, aeroallergens" --- p.12 / Chapter 1.2.7 --- Dysregulation of innate immune system --- p.13 / Chapter 1.2.7.1 --- Dysregulation of antimicrobial peptides --- p.14 / Chapter 1.2.7.2 --- Skin barrier impairment --- p.14 / Chapter 1.2.8 --- Genetic predisposition --- p.15 / Chapter 1.3 --- Assessments of Atopic Eczema (AE) --- p.17 / Chapter 1.3.1 --- AE severity assessment --- p.17 / Chapter 1.3.1.1 --- Scoring of atopic dermatitis (SCORAD) system --- p.17 / Chapter 1.3.1.2 --- Nottingham eczema severity score (NESS) --- p.20 / Chapter 1.3.2 --- Dermatological parameter - skin hydration (SH) and transepidermal water loss (TEWL) --- p.22 / Chapter 1.4 --- Chitinase (CHIA) --- p.22 / Chapter 1.4.1 --- Chitin and CHIA --- p.22 / Chapter 1.4.2 --- Association of acid mammalian chitinase (AMCase) with asthma --- p.23 / Chapter 1.4.3 --- Hygiene hypothesis implies: AMCase and allergy relationship --- p.24 / Chapter Chapter 2: --- Hypothesis and Objectives --- p.25 / Chapter 2.1 --- Hypothesis - based on CHIA involvements in canine AE --- p.25 / Chapter 2.2 --- Hypothesis --- p.25 / Chapter 2.3 --- Objective 226}0ؤ based on AMCase single nucleotide polymorphism (SNPs) in asthma susceptibility --- p.25 / Chapter 2.4 --- Objectives --- p.27 / Chapter Chapter 3: --- Methodology --- p.28 / Chapter 3.1 --- Recruitment of cases and controls --- p.28 / Chapter 3.2 --- Assessment of clinical parameters --- p.29 / Chapter 3.2.1 --- Scoring of atopic dermatitis (SCORAD) system --- p.29 / Chapter 3.2.2 --- Nottingham eczema severity score (NESS) --- p.29 / Chapter 3.2.3 --- Dermatologic parameters --- p.29 / Chapter 3.2.3.1 --- Cutaneous bacterial colonization --- p.29 / Chapter 3.2.3.2 --- Skin hydration (SH) and transepidermal water loss (TEWL) --- p.30 / Chapter 3.3 --- Peripheral blood collection and genomic deoxyribonucleic acid (DNA) extraction --- p.30 / Chapter 3.4 --- Acid mammalian chitinase (AMCase) polymorphism genotyping --- p.31 / Chapter 3.4.1 --- Polymerase chain reactions (PCR) amplification of AMCase gene --- p.31 / Chapter 3.4.1.1 --- List of PCR reagents --- p.32 / Chapter 3.4.1.2 --- Electrophoresis reagents --- p.33 / Chapter 3.4.2 --- Restriction fragment length polymorphism (RFLP) analysis of AMCase and confirmation with direct sequencing --- p.33 / Chapter 3.5 --- Statistical analysis --- p.34 / Chapter Chapter 4: --- Results and Data Analysis --- p.36 / Chapter 4.1 --- Results --- p.36 / Chapter 4.1.1 --- Demographic data of cases and controls --- p.36 / Chapter 4.1.2 --- PCR amplification and RFLP analysis of AMCase gene --- p.37 / Chapter 4.1.3 --- PCR cycle sequencing of the PCR fragments --- p.40 / Chapter 4.2 --- Data analysis --- p.41 / Chapter 4.2.1 --- Data overview --- p.41 / Chapter 4.2.2 --- Genotypes distribution of AMCase polymorphisms --- p.43 / Chapter 4.2.2.1 --- Allele frequency comparison of AMCase single nucleotide polymorphism (SNPs) by chi-square --- p.43 / Chapter 4.2.2.2 --- Allele frequency comparison of AMCase SNPs by logistic regression analysis --- p.44 / Chapter 4.2.3 --- Haplotype frequency estimation via maximum likelihood algorithm --- p.45 / Chapter 4.2.4 --- Association of AMCase polymorphism with Atopic Eczema (AE) clinical parameters --- p.47 / Chapter 4.2.4.1 --- Peripheral blood eosinophil counts --- p.48 / Chapter 4.2.4.2 --- Serum immunoglobin E (IgE) level --- p.49 / Chapter 4.2.4.3 --- Dermatologic factors --- p.49 / Chapter 4.2.4.3.1 --- Cutaneous Staphylococcus aureus colonization --- p.49 / Chapter 4.2.4.3.2 --- Skin hydration (SH) and transepidermal water loss (TEWL) --- p.50 / Chapter Chapter 5: --- Discussion --- p.52 / Chapter 5.1 --- Data overview --- p.52 / Chapter 5.2 --- AMCase rs3806448 polymorphism was significantly different among AE cases and controls --- p.53 / Chapter 5.2.1 --- Allele frequency comparison of AMCase SNPs polymorphisms by chi-square --- p.53 / Chapter 5.2.2 --- Allele frequency comparison of AMCase SNPs polymorphisms by logistic regression analysis --- p.54 / Chapter 5.2.3 --- The possible genetic modification by rs3806448 homozygous recessive genotype --- p.55 / Chapter 5.3 --- "Significant difference of haplotype frequency, 2212 among case-control comparison" --- p.56 / Chapter 5.4 --- Strong associations between AMCase SNPs polymorphisms and clinical parameters of AE --- p.57 / Chapter 5.4.1 --- Peripheral blood eosinophil counts --- p.57 / Chapter 5.4.2 --- Dermatologic factors --- p.58 / Chapter 5.4.2.1 --- Cutaneous Staphylococcus aureus colonization --- p.58 / Chapter 5.4.2.2 --- Skin hydration (SH) and transepidermal water loss (TEWL) --- p.59 / Chapter 5.5 --- Limitation of the present study --- p.59 / Chapter Chapter 6: --- Conclusion and Future Prospect --- p.62 / Chapter 6.1 --- Conclusion --- p.62 / Chapter 6.2 --- Future prospect --- p.62 / Chapter Chapter 7: --- Appendices --- p.64 / Chapter Chapter 8: --- References --- p.69
104

Genetic polymorphisms in the stearoyl-CoA desaturase1 (SCD1) gene and their influence on the conjugated linoleic acid (CLA) and monounsaturated fatty acids (MUFA) content of milk fat of Canadian Holstein and Jersey cows

Kgwatalala, Patrick M., 1973- January 2008 (has links)
Stearoyl-CoA desaturase1 (SCD1) catalyzes the synthesis of conjugated linoleic acid (CLA) and mono-unsaturated fatty acids (MUFA) in the mammary gland of ruminant animals. We hypothesized that single nucleotide polymorphisms (SNPs) in the coding region, 5' and 3' untranslted regions (UTRs) of the SCD1 gene would influence the activity of SCD1 enzyme and consequently account for some within-breed variations in milk CLA and MUFA. Sequence analysis of the coding region of the SCD1 gene of Jerseys and Holsteins revealed c.702A&rarr;G, c.762T&rarr;C and c.878C&rarr;T SNPs in exon 5 in both breeds and c.435G&rarr;A in exon 3 in Holsteins. The SNPs resulted in: A (G435A702T 762C878), A1 (A435A702T 762C878), B (G435G702C 762T878) and B1 (A435G702C 762T878) coding variants in Holsteins and only variants A and B in Jerseys. Only SNP 878C&rarr;T resulted in a non-synonymous codon change resulting in p.293Ala and p.293Val protein variants or alleles at the SCD1 locus. Subsequent association studies found significantly higher C10 index, C12 index and C14 index and consequently higher concentrations of C10:1 and C12:1 in p.293AA cows compared to the p.293VV cows in both breeds. The SCD1 genotype had no influence on concentrations of C141, C16:1, C18:1 and CLA in both breeds. / Sequence analysis of the 5' and 3' UTRs revealed no SNPs in the 5'UTR and a total of 14 SNPs in the 3'UTR of both breeds. The SNPs were in complete linkage disequilibrium resulting in 3 haplotypes or regulatory variants: H1 (G1571G1644C1763C2053A2584 A3007C3107G3208 T3290G 3497G3682A4399C4533G4881), H2 (G1571G1644A1763C2053A 2584G3007 C3107G3208T3290G3497G 3682A4399C4533G4881) and H3 (T 1571C1644A1763 T2053G2584G3007T 3107A3208C3290A3497A3682T 4399T4533A4881) in Holsteins and only H1 and H3 variants in Jerseys. A subsequent association study involving 862 Holstein cows, found the H1 regulatory variant to be associated with higher C10 and C12 desaturase indices and consequently with higher concentrations of C10:1 and C12:1 compared with the H3 variant. The effects of the H2 variant were intermediate to those of H1 and H3. 3'UTR genotype had no influence on the concentrations of C14:1, C16:1, C18:1 and CLA. The concentrations of C10:1 and C12:1 in milk fat could therefore be due to effects of SNPs in the open reading frame and the 3'UTR regions of the SCD1 gene. These results indicate that SNPs in the coding and 3'UTR regions of the SCD1 gene could be used as markers for genetic selection for increased C10:1 and C12:1 contents of milk.
105

Inflammatory bowel disease in twins : studies of genetics and environmental factors /

Halfvarson, Jonas, January 2005 (has links) (PDF)
Diss. Linköping : Linköpings universitet, 2005.
106

Genetic Variation and Expression of the IRF5 Gene in Autoimmune Diseases /

Kristjansdottir, Gudlaug Thora, January 2009 (has links)
Diss. (sammanfattning) Uppsala : Univ., 2009. / Härtill 4 uppsatser.
107

Genetic Variation and Expression of the IRF5 Gene in Autoimmune Diseases

Kristjansdottir, Gudlaug Thora, January 2009 (has links)
Diss. (sammanfattning) Uppsala : Uppsala universitet, 2009. / Härtill 4 uppsatser.
108

Análise da expressão do KISS1/KISS1  do polimorfismo rs5780218 KISS1 em somatotropinomas e adenomas hipofisários clinicamente não funcionantes / Investigation of KISS1/KISS1R gene expression and KISS1 rs5780218 polymorphism in somatotropinomas nonfunctioning pituitary adenomas

Paulo Vinícius Gonçalves Holanda Amorim 20 April 2018 (has links)
Apesar de amplamente estudados, os mecanismos envolvidos no processo de transformação neoplásica das células hipofisárias e na progressão desses tumores permanecem, ainda, pouco esclarecidos. Os genes da kisspeptina (KISS1), originalmente identificado como um supressor tumoral, e de seu receptor (KISS1R) desempenham um papel crucial no eixo hipotalâmico-hipofisário-gonadal e sua perda de expressão foi, recentemente, relacionada ao surgimento dos adenomas hipofisários. Com o objetivo de estudar a importância do KISS1/KISSR nesses tumores, foram avaliadas a expressão desses genes e a frequência do polimorfismo rs5780218 na região promotora do KISS1, em somatotropinomas e adenomas hipofisários clinicamente não funcionantes (ACNF). Foram avaliados 97pacientes, 49 somatotropinomas e 48 ACNF. DNA tumoral foi obtido de todos os tumores e RNA de 68 caso. Desses tumores, 52 foram classificados como invasivos (44 apresentavam invasão apenas para o seio cavernoso) e 45 não invasivos. A quantificação da expressão do mRNA de KISS1 e KISS1R foi realizada pela qPCR em tempo real com sondas TaqMan utilizando o método de quantificação relativa 2-deltaCt. A determinação do genótipo do rs5780218 foi feita por PCR seguida pela técnica de polimorfismo no comprimento do fragmento de restrição (RFLP). O gene KISS1 apresentou-se hipo-expresso na vasta maioria dos pacientes avaliados (97.2% dos somatotropinomas e 92.6% do ACNF). Em relação ao KISS1R, este também estava hipo-expresso na maior parte dos pacientes (100% dos somatotropinomas e 84.4% dos ACNF). Hiperexpressão do KISS1 e KISS1R foi rara em ambos os subtipos tumorais. Em relação as características clínicas dos pacientes e ao fenótipo tumoral, como tamanho e invasividade, não foram encontradas diferenças significantes na expressão desses genes. A avaliação do polimorfismo rs5780218 no KISS1 mostrou que o genótipo homozigoto para o alelo variante foi bem mais frequente nos somatotropinomas (32.6%) versus ACNF (10.4%; P=0.03). A presença do rs5780218 foi relacionada a invasividade tumoral, quando considerado apenas a invasão para o seio cavernoso (P=0.03). Esse é um dado interessante, já que a KISS1 pode formar um complexo com as metaloproteinases e estas têm sido relacionadas a invasão dos adenomas hipofisários para o seio cavernoso e não para o seio esfenoidal. Entre os pacientes com ACNF, o alelo variante foi mais frequente nos indivíduos do sexo masculino (P=0.02) e foi relacionado com uma menor idade de diagnóstico (mediana 33.0 anos, min 26 - max 42) quanto presente em homozigose (P < 0.01); os pacientes homozigotos para o alelo ancestral e heterozigotos apresentaram idade diagnóstica com mediana de 50.0 (min 19 - max 73) e 54.8 (min 17- max 84), respectivamente. Curiosamente, a expressão do KISS1 foi menor nos tumores com homozigose para o alelo mutante tantos nos somatotropinomas quanto nos ACNF. Em conclusão, foi observada hipo-expressão do KISS1 e KISS1R nos somatotropinomas e ACNF, podendo essa perda expressão estar relacionada a gênese desses adenomas. O alelo variante rs5780218 KISS1 foi relacionado a invasão para o seio cavernoso e encontrado em maior frequência nos somatotropinomas, sugerindo que a importância dos KISS1/KISS1R pode diferir entre os subtipos de tumores hipofisários / Although broadly studied, the mechanisms involved in the neoplastic process of pituitary cells remains still unclear. Kisspeptin1 (KISS1), originally identified as a tumor suppressor, and its receptor (KISS1R) play a crucial role in the hypothalamic-pituitary-gonadal axis and the loss of their expression was, recently, associated with pituitary adenomas onset. Aiming to investigated the importance of KISS1/KISS1R in these tumors, expression of KISS1 and KISS1R was determined in somatotropinomas and nonfunctioning pituitary adenomas (NFPA). The frequency of the rs5780218 polymorphism, located in the KISS1 promoter region, was also evaluated. A total of 97 patients were assessed, 49 somatotropinomas and 48 NFPA. Among these, 52 were categorized as invasive (44 of which only showed invasion to the cavernous sinus). KISS1 and KISS1R mRNA expression was performed through RT-qPCR using TaqMan probes and the 2-deltaCt relative quantification method. KISS1 rs5780218 genotyping was done by PCR and restriction fragment length polymorphism (RFLP) method. The KISS1 gene was underexpressed in the vast majority of the cases (97.2% of the somatotropinomas and 92.6% of NFPA). KISS1Runderexpression have also been observed in most cases (100% of the somatotropinomas and 84.4% of the NFPA). KISS1 and KISS1R overexpression was rarely detected. No significant differences were found between KISS1 and KISS1R gene expression and patient\'s clinical characteristics and tumor phenotype, such as size and invasiveness. The characterization of rs5780218 showed that the variant genotype in homozygosis was much more frequent in somatotropinomas (32.6%) versus NFPA (10.4%; P=0.03). The presence of variant allele was associated with tumor invasiveness when considered invasion to the cavernous sinus only (P=0.03). This data is particularly interesting, since KISS1 has the ability for form a complex with metalloproteinases and these, for instance, are related to invasiveness of pituitary adenomas to the cavernous, but not to the sphenoidal, sinus. When considered only NFPA, the variant allele was more frequent in males (P=0.02) and was associated with earlier age at presentation (median 33 years old, min 26 - max 42) when in homozygosis (P < 0.01); the wilt-type homozygotes and heterozygotes had medians of 50.0 (min 19 - max 73) and 54.8 (min 17 - max 84), respectively. Curiously, KISS1 expression was lower in rs5780218 homozygotes both in somatotropinomas and NFPA. In conclusion, we have identified the KISS1 and KISS1R underexpression in both somatotropinomas and NFPA, which lead to notion that the loss of expression might be related to the genesis of these adenomas. The rs5780218 KISS1 variant allele was associated with invasion to the cavernous sinus and was found to be more frequent in somatotropinomas, suggesting that role of KISS1/KISS1R in tumor behavior might differ between pituitary adenomas subtypes
109

O polimorfismo de um único nucleotídeo rs713041 no gene GPX4 modula a susceptibilidade à neuropatia autonômica cardiovascular em portadores de diabetes mellitus tipo 1 / The polymorphism of a single nucleotide rs713041 in the GPX4 gene modulates the susceptibility to cardiovascular autonomic neuropathy in patients with type 1 diabetes mellitus

Sharon Nina Admoni 06 June 2017 (has links)
Introdução: As neuropatias periférica (NP) e autonômica cardiovascular (NAC) são complicações prevalentes do diabetes mellitus (DM). Há indícios de que seu desenvolvimento se deve não somente ao controle metabólico. Neste sentido, a busca por preditores genéticos faz-se imperativa. Diversos genes relacionados às vias bioquímicas que levam ao dano celular induzido pela hiperglicemia têm sido investigados, destacando-se os genes relacionados às vias do extresse oxidativo. O balanço entre os sistemas antioxidantes (como glutationa e tiorredoxina) e pró-oxidantes (como o NADPH-oxidase) é um importante fator na defesa celular contra o estresse oxidativo. Objetivo primário: avaliar a associação entre os polimorfismos de um único nucleotídeo (SNP) pertencentes às vias anti- e pró-oxidantes mencionadas e a NP e NAC em pacientes DM tipo 1: 718C/T na região 3\' UTR (untranslated region) (rs713041) no gene da glutationa peroxidase 4 (GPX4); -129 C/T (rs1788390) no gene da glutamato cisteína ligase (GLCL); -1365 C/T (rs7211) no gene da proteína de interação com a tiorredoxina (TXNIP); -2810 A/G (rs6610650) no gene do CYBB; - 675 T/A (não registrado) no gene do CYBA. Objetivo secundário: avaliar a relação entre as diferentes complicações microvasculares entre si (neuropatia, doença renal diabética [DRD] e retinopatia diabética [RD]). Material e métodos: foram selecionados 378 pacientes com DM tipo 1 do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo e do Hospital das Clínicas da Universidade Estadual de Campinas com mais de 10 anos de doença e controle inadequado (HbA1c >8% em algum período da vida), e examinados para NP e NAC. A genotipagem dos polimorfismos foi realizada pela técnica de reação em cadeia da polimerase em tempo real (Sistema Taqman ®). Foram avaliadas variáveis clínicas, laboratoriais do metabolismo glicêmico e lipídico e a presença de DRD e de RD. Foram avaliados 257 pacientes retrospectivamente quanto à evolução da taxa de filtração glomerular estimada (TFGe) em relação à NP e NAC. O teste de Pearson foi usado para comparar as frequências dos genótipos e a magnitude de associação foi estimada pelo cálculo do odds ratios (OR), com respectivo intervalo de confiança (IC) ajustada por regressão logística para possíveis fatores de confusão. Resultados: A presença de pelo menos um alelo T do SNP +718C/T no gene GPX4 conferiu proteção para NAC (OR=0,39; IC 95% 0,17 - 0,84; P = 0,0165). Na análise de associação entre as complicações, observou-se que: (1) na presença de NP há aumento na probabilidade de NAC (OR = 3,38; IC95% 2,01 - 5,73; P < 0,0001), de albuminúria A3 (OR = 7,17; IC95% 3,68 - 14,53; P < 0,0001) e de RD proliferativa (OR = 9,58; IC95% 5,04 - 19,09; P < 0,0001) e (2) na presença de NAC há aumento na probabilidade de NP (OR = 3,72; IC95% 2,14 - 6,53; P < 0,0001), de albuminuria A3 (OR = 9,37; IC95% 4,68 - 19,65; P < 0,0001) e de RD proliferativa (OR = 3,30; IC95% 1,81 - 6,18, P < 0,0001). No subgrupo avaliado retrospectivamente, a presença de NP e de NAC associou-se com queda de TFGe anual maior (-4,74 mL/min/ano vs. -1,22 mL/min/ano; P < 0,0001 e -3,74 mL/min/ano vs. -1,54 mL/min/ano; P = 0,04, respectivamente). Conclusões: (1) a presença do alelo T no SNP +718C/T (rs713041) no gene GPX4 confere proteção para NAC na população com DM tipo 1 estudada e (2) existe associação de risco para NP e NAC entre si e para as formas graves de DRD e RD / Introduction: Peripheral (PN) and cardiovascular autonomic neuropathies (CAN) are prevalent complications of diabetes mellitus (DM). There are indications that their development occurs not only secondary to metabolic control. Thus, search for genetic predictors is very important. Several genes related to the biochemical pathways that lead to cellular damage induced by hyperglycemia have been investigated, emphasizing the genes related to the pathways of oxidative stress. The balance between antioxidant systems (such as glutathione and thioredoxin) and pro-oxidants (such as NADPH oxidase) is an important factor in cell defense against oxidative stress. Primary objective: to evaluate the association between the single nucleotide polymorphisms (SNP) of the mentioned anti-and pro-oxidant pathways and NP and NAC in type 1 DM patients: 718C / T in the 3 \'UTR (untranslated region) (rs713041) of the glutathione peroxidase 4 gene (GPX4); -129 C / T (rs1788390) in the glutamate cysteine ligase gene (GLCL); -1365 C / T (rs7211) in the thioredoxin interaction protein gene (TXNIP); -2810 A / G (rs6610650) in the CYBB gene; - 675 T / A (unregistered) in the CYBA gene. Secondary objective: to evaluate the relationship between different microvascular complications (neuropathy, diabetic renal disease [DRD] and diabetic retinopathy [DR]). Material and methods: 378 type 1 patients DM were selected from the Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo and from Hospital das Clínicas da Universidade Estadual de Campinas; they had more than 10 years of disease and inadequate control (HbA1c > 8% at some period of life), and were examined for NP and NAC. Polymorphism genotyping was performed by real-time polymerase chain reaction (Taqman System®). Clinical, glycemic and lipid metabolism laboratorial variables and the presence of DRD and DR were evaluated. Also 257 patients were retrospectively evaluated regarding the evolution of the estimated glomerular filtration rate (eGFR) in relation to PN and CAN. The Pearson test was used to compare the frequencies of the genotypes and the magnitude of association was estimated by the odds ratios (OR), with the respective confidence interval (CI) adjusted by logistic regression for possible confounding factors. Results: The presence of at least one T allele at the SNP + 718C / T of the GPX4 gene protected for CAN (OR = 0.39; 95% CI 0.17-0.84; P = 0.0165). In the analysis of the association between complications, it was observed that: (1) in the presence of NP, there was an increase in risk of NAC (OR = 3.38; 95% CI 2.01 - 5.73; P < 0.0001), of albuminuria A3 (OR = 7.17; 95% CI 3.68 - 14.53; P < 0.0001) and of proliferative DR (OR = 9.58; 95% CI, 5.04 - 19.09; P < 0.0001) (2) in the presence of CAN, there was an increase in risk of PN (OR = 3.72; 95% CI 2.14 - 6.53; P < 0.0001), albuminuria A3 (OR = 9.37; CI95% 4.68 - 19.65; P<0,0001) and proliferative DR (OR = 3.30; CI95% 1.81 - 6.18; P < 0,0001).) In the subgroup evaluated retrospectively, the presence of PN and CAN was associated with a greater annual decrease of eGFR (-4.74 mL / min / year vs. -1.22 mL / min / year, P < 0.0001 and - 3.74 mL / min / yr vs. -1.54 mL / min / yr, P < 0.04, respectively). Conclusions: (1) the presence of the T allele at the SNP + 718C / T (rs713041) in the GPX4 gene confers protection for the presence of CAN in the studied type 1 DM population and (2) there is a risk association for PN and CAN among themselves and for severe forms of DRD and RD
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Efeito dos polimorfismos nos genes  da leptina e do receptor da leptina sobre a compulsão alimentar em crianças e adolescentes obesos / Effect of polymorphisms in the leptin and leptin receptor genes on binge eating in obese children and adolescents

Clarissa Tamie Hiwatashi Fujiwara 31 July 2014 (has links)
INTRODUÇÃO: A obesidade na infância e adolescência representa uma epidemia global e figura como um problema de saúde pública proeminente de prevalência crescente. A obesidade frequentemente está associada à compulsão alimentar periódica (CAP) e componentes genéticos participam de sua etiologia multifatorial. Polimorfismos de nucleotídeo único (SNPs) no gene da leptina (LEP) e do receptor da leptina (LEPR) podem modificar a expressão da leptina e de suas vias de sinalização e, consequentemente, alterar a regulação do apetite e da saciedade, contribuindo assim para a etiopatogenia e manutenção da CAP. O objetivo deste trabalho foi investigar a influência dos polimorfismos rs7799039 (G > A) no gene LEP e rs1137100 (A > G), rs1137101 (A > G) e rs8179183 (G > C) no gene LEPR sobre a CAP em crianças e adolescentes obesos, além de caracterizar a população quanto à CAP e verificar a associação dos SNPs com o risco cardiometabólico (RCM) e a obesidade. MÉTODOS: Estudo transversal que incluiu 465 crianças e adolescentes obesos com idade entre 7 e 19 anos avaliados quanto a variáveis antropométricas e metabólicas. Os fatores de RCM consistiram de hipertensão arterial sistêmica, glicemia de jejum alterada, HDL-colesterol baixo e hipertrigliceridemia. A CAP foi avaliada por meio da Escala de Compulsão Alimentar Periódica (ECAP). Para investigar o efeito dos SNPs no risco para a obesidade foi incluído um grupo controle composto por 135 crianças e adolescentes eutróficos. A genotipagem foi realizada por PCR em tempo real e para análise dos SNPs, adotou-se o modelo dominante. Foi calculado o desequilíbrio de ligação entre os SNPs e estimada as frequências dos haplótipos. As comparações entre os grupos foram realizadas estratificadamente por gênero e estádio puberal. Para avaliar a magnitude do risco dos SNPs sobre a CAP e a obesidade foi realizada regressão logística ajustada para variáveis de confusão (idade, Z-IMC e estádio puberal). RESULTADOS: As crianças e adolescentes obesos (12,5 ± 2,9 anos; 52,7% meninas) classificados com CAP apresentaram maior adiposidade e a frequência da CAP foi mais elevada no gênero feminino (OR= 2,146; IC 95% 1,461-3,152; p < 0,001). A frequência do alelo A do rs7799039 foi mais elevada no grupo de obesos (OR= 1,530; IC 95% 1,022-2,292; p= 0,039) e o alelo associou-se ao maior nível de leptina e colesterol total em meninas e à maior glicemia em meninos (p < 0,05). No rs1137100 e o rs1137101, a presença do alelo G em meninas conferiu risco para a hipertrigliceridemia (OR= 1,926; IC 95% 1,010-3,673; p= 0,047 e OR= 2,039; IC 95% 1,057-3,931; p= 0,033, respectivamente). O alelo C do rs8179183 relacionou-se, em meninas, à relação cintura-estatura e glicemia mais elevadas e, em meninos, ao maior percentil de pressão arterial diastólica, glicemia, colesterol total e LDL-colesterol (p <0,05). CONCLUSÃO: Os polimorfismos não foram associados à compulsão alimentar periódica. A CAP foi relacionada ao pior grau de adiposidade e o maior risco foi observado no gênero feminino. O SNP rs7799039 no gene LEP conferiu risco para obesidade, enquanto o rs1137100, rs1137101 e rs8179183 no gene LEPR relacionaram-se ao pior perfil cardiometabólico em crianças e adolescentes obesos / INTRODUCTION: Obesity during childhood and adolescence represents a global epidemic and consists in a prominent public health issue of increasing prevalence. Obesity is frequently associated with binge eating (BE) and genetic factors participate of its multifactorial etiology. Single nucleotide polymorphisms (SNPs) in the leptin (LEP) and leptin receptor (LEPR) genes may modify the leptin expression and its signaling pathways and, consequently, alter appetite and satiety regulation, thus contributing to the etiopathogeny and maintenance of BE. The aim of this study was to investigate the influence of polymorphisms rs7799039 (G > A) in the LEP gene and rs1137100 (A > G), rs1137101 (A > G) and rs8179183 (G > C) in the LEPR gene on BE in obese children and adolescents, besides characterize the population regarding to BE and examine the association of SNPs with cardiometabolic risk (CMR) and obesity. METHODS: Cross-sectional study in which 465 obese children and adolescents aged from 7 to 19 years were enrolled and had anthropometric and metabolic variables assessed. The CMR factors consisted of systemic hypertension, impaired fasting glucose, low HDL-cholesterol levels and hypertriglyceridemia. The BE was evaluated through the Binge Eating Scale (BES). To investigate the effect of SNPs on obesity risk, a control group of 135 eutrophic children and adolescents was enrolled. Genotyping was performed by real-time PCR and for the SNPs analysis, the dominant model was adopted. The linkage disequilibrium between SNPs was calculated and the haplotype frequencies were estimated. Comparisons between groups were performed stratified by gender and pubertal stage. To assess the risk magnitude for the SNPs on BE and obesity, logistic regression adjusted for confounding variables (age, Z-BMI and pubertal stage) was performed. RESULTS: Obese children and adolescents (12.5 ± 2.9 years, 52.7% girls) classified with BE showed greater adiposity and BE frequency was higher among females (OR= 2.146; 95% CI 1.461-3.152; p < 0.001). The observed frequency of A allele of rs7799039 was a higher in the obese group (OR= 1.530; 95% CI 1.022-2.292; p= 0.039) and the allele was associated with higher leptin and total cholesterol levels in girls and higher glucose levels in boys (p < 0.05). For the rs1137100 and rs1137101, the presence of the G allele among girls, conferred risk for hypertriglyceridemia (OR= 1.926; 95% CI 1.010-3.673; p= 0.047 and OR= 2.039; 95% CI 1.057-3.931; p= 0.033, respectively). The C allele of rs8179183 was associated, among girls, with a higher waist-to-height ratio and glucose levels and, among boys, with greater diastolic blood pressure percentile, glucose, total cholesterol and LDL-cholesterol levels (p < 0.05). CONCLUSION: Polymorphisms were not associated with binge eating. BE was related with a more severe adiposity and an increased risk was observed among females. The SNP rs7799039 in the LEP gene contributed to the risk of obesity, whereas the rs1137100, rs1137101 and rs8179183 in LEPR gene were related to a worse cardiometabolic profile in obese children and adolescents

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