Stroke, a major cause of death and disability, is described as interruption or severe reduction of blood flow in cerebral arteries. Oxidative stress plays an important role in the pathogenesis of atherosclerosis and carotid atherosclerosis is a risk factor for stroke. Combination of multiple environmental and genetic risk factors is thought to increase susceptibility to the development of this disease. Therefore, investigation of the polymorphisms of drug metabolizing enzymes is of crucial importance to determine the molecular etiology of the disease. The main objective of this study was to investigate the possible association between polymorphisms of enzymes causing oxidative stress (CYP2E1, FMO3 and NOS3) and enzymes protecting against oxidative stress (GST and NQO1), and the pathogenesis of atherosclerosis and ischemic stroke risk. The study population consisted of 245 unrelated ischemic stroke patients and 145 healthy control subjects. There was no statistically difference between the patient and control groups in terms of age and gender. Hypertension, diabetes, smoking and obesity were found to be at least 2 times more common in stroke patients than controls. While total cholesterol, triglyceride and LDL-cholesterol level were higher in stroke patients, HDL-cholesterol level was lower in stroke patients when compared to controls. In the case-control analyses for the risk of ischemic stroke, CYP2E1*5B mutant allele, *5B was found to be associated with the development of disease (Odds Ratio / OR=7.876, 95%CI=1.025-60.525, P=0.019). In addition, significant difference was observed between stroke patients and controls with respect to CYP2E1*5B genotype distribution (OR=0.869, 95%CI=1.044-62.339, P=0.017). On the other hand, in the NQO1*2 polymorphism, together with NQO1 heterozygote (*1*2), NQO1 homozygote mutant (*2*2) genotype was found protective against ischemic stroke (OR=0.627, 95%CI=0.414-0.950, P=0.027). The risk of hypertensive individuals having stroke was highest in the FMO3 472GA group (OR=6.110, P=0.000). In diabetics, GSTP1 313AG genotype was found to be the highest risk factor for stroke (OR=3.808 P=0.001). On the other hand, NQO1 *1*2 heterozygote genotype was associated with 5 times increased risk for stroke in smokers (OR=5.000, P=0.000). In addition GSTM1 present genotype constituted 8 times increased stroke risk in obese individuals (OR=8.068, P=0.001). Logistic regression analysis revealed that hypertension, diabetes mellitus, obesity and smoking were significant risk factors for stroke. On the other hand, HDL-cholesterol and having NQO1 *1*2 heterozygote genotype were found to be protective factors against stroke.

Orientador: Claudia Regina Bonini Domingos / Banca: Antonio Fabron Junior / Banca: Luiz Carlos de Mattos / Banca: Sonia Maria Oliani / Banca: Wilson Araújo Silva Junior / Resumo: Na talassemia beta, o acúmulo das cadeias alfa livres, bem como a liberação do grupo heme e do ferro durante o processo hemolítico, ocasionam aumento de danos oxidativos que podem resultar em lipoperoxidação de membranas celulares, desnaturação de proteínas e oxidação da hemoglobina. Na deficiência de glicose- 6-fosfato desidrogenase (G6PD), esse aumento é decorrente da diminuição da produção de nicotinamida adenina dinucleotídeo fosfato reduzido (NADPH) que pode resultar em hemólise intravascular. Diante da possibilidade de estresse oxidativo nos portadores de beta talassemia heterozigota e nos indivíduos com deficiência de G6PD, neste trabalho avaliou-se a expressão fenotípica das afecções genéticas por meio da identificação das mutações e análise de marcadores para estresse oxidativo. Para o estabelecimento dos grupos controle e com deficiência de G6PD foram avaliadas 544 amostras de sangue periférico de indivíduos da região Noroeste do Estado de São Paulo, sendo 426 doadores de sangue e 118 indivíduos de uma instituição de ensino superior. Para a composição do grupo com talassemia beta heterozigota foram avaliadas 46 amostras de sangue de indivíduos com diagnóstico clínico de talassemia beta da cidade de São Carlos/SP. Foram realizados métodos de triagem e confirmatórios para a identificação da talassemia beta heterozigota e da deficiência de G6PD, e dosagens bioquímicas para quantificação das espécies reativas ao ácido tiobarbitúrico (TBARS), utilizado como marcador de estresse oxidativo, e para a determinação da capacidade antioxidante em equivalência ao Trolox (TEAC). Os polimorfismos da glutationa S-transferase (GST) GSTM1 e GSTT1 foram avaliados por PCR multiplex o de GSTP1 por PCR/RFLP. No grupo com talassemia beta heterozigota foram encontradas 18 (39%) amostras com a mutação CD39; 22 (48%) com a mutação... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In beta thalassemia, the excess of unpaired alpha chains, as well as the heme group and iron released during the hemolytic process increase the oxidative damage. In G6PD deficiency, this increase is caused by a reduced production of NADPH that results in an intravascular hemolysis. Thus, facing the oxidative stress possibility in beta thalassemia carriers and G6PD deficiency individuals, it was aimed to evaluate the fenotypic expression of this genetic disorders through the mutation identification, as well as the oxidative stress marker analysis. We used 544 peripheral blood samples of individuals from São Paulo's northwestern to control group and to G6PD deficiency group establishment. For beta thalassemia heterozygote group were evaluated 48 blood samples of São Carlos/SP city. Tests were carried out aiming the screening and confirmation of beta thalassemia and G6PD deficiency, as well as the analysis of lipid peroxidation products measured as thiobarbituric acid reactive species (TBARS) and Trolox equivalent antioxidant capacity (TEAC). Were determined the frequencies of GSTM1, GSTT1 and GSTP1 polymorphisms. The analysis with beta thalassemia carriers allowed to establish in the study group a frequency of 39% for CD39 mutation, 48% for IVS-I-110 mutation and 2% for IVS-I-6 mutation. For G6PD deficiency was founded a frequency of 3.86%. The beta thalassemic group evaluation showed an increase of TBARS and TEAC values, when compared to the control group. There was a tendency to increase lipid peroxidation in beta0 CD39 mutants compared to beta+ IVS-I-110 mutants, because there is more free chains amount in beta0 thalassemia than beta+ thalassemia. In the G6PD deficiency analysis was found a lower G6PD activity in men than in women, but there was no interference of gender in the TBARS and TEAC assays results. The comparison between the control group and the G6PD deficiency group... (Complete abstract click electronic access below) / Doutor

Background: The adequacy of serum ascorbic acid (vitamin C) concentrations in young Canadian adults is unknown. Individuals have varied serum ascorbic acid response to dietary vitamin C, possibly due to genetic variation. Objective: To investigate the prevalence of serum ascorbic acid deficiency in young Canadians and to determine whether common genotypes modify the association between dietary vitamin C and serum ascorbic acid. Methods: Subjects were 1277 men and women aged 20-29 years from the Toronto Nutrigenomics and Health study. Vitamin C intakes were estimated by a 196-item FFQ. Fasting blood was collected to measure serum ascorbic acid by HPLC and to genotype for common polymorphisms in genes that code for glutathione S-transferase (GST) (GSTM1, GSTT1 and GSTP1), haptoglobin (Hp), and vitamin C transporters (SLC23A1 and SLC23A2). Results: 53% of subjects had adequate, 33% had suboptimal and 14% had deficient serum ascorbic acid. Subjects with deficiency had higher mean C-reactive protein, waist circumference, BMI and blood pressure than subjects with adequate serum ascorbic acid. The odds ratio (95% confidence interval) for serum ascorbic acid deficiency was 3.43 (2.14, 5.50) for subjects who did not meet the vitamin C recommendation compared to those who did. The corresponding odds ratios were 2.17 (1.10, 4.28) and 12.28 (4.26, 33.42) for individuals with the GSTT1 functional and null genotypes respectively (interaction p=0.01), and 2.29 (0.96, 5.45) and 4.03 (2.01, 8.09) for the GSTM1 functional and null genotypes (interaction p=0.04). These odds ratios were 4.77 (2.36, 9.65) for the Hp2-2 genotype, but 1.69 (0.80, 3.63) for carriers of the Hp1 allele (interaction p=0.02). Serum ascorbic acid concentrations (mean +/- SE) differed among SLC23A1 rs4257763 genotypes (GG: 24.4 +/- 1.3, GA: 26.8 +/- 1.1, AA: 29.7 +/- 1.4, p=0.002). Conclusions: Serum ascorbic acid deficiency is prevalent and associated with markers of chronic disease. Individuals with GST null or Hp2-2 genotypes had an increased risk of deficiency if they did not meet the recommendation for vitamin C, suggesting that GSTs and haptoglobin may spare ascorbic acid when dietary vitamin C is insufficient, thus protecting against serum ascorbic acid deficiency.

Background: The adequacy of serum ascorbic acid (vitamin C) concentrations in young Canadian adults is unknown. Individuals have varied serum ascorbic acid response to dietary vitamin C, possibly due to genetic variation. Objective: To investigate the prevalence of serum ascorbic acid deficiency in young Canadians and to determine whether common genotypes modify the association between dietary vitamin C and serum ascorbic acid. Methods: Subjects were 1277 men and women aged 20-29 years from the Toronto Nutrigenomics and Health study. Vitamin C intakes were estimated by a 196-item FFQ. Fasting blood was collected to measure serum ascorbic acid by HPLC and to genotype for common polymorphisms in genes that code for glutathione S-transferase (GST) (GSTM1, GSTT1 and GSTP1), haptoglobin (Hp), and vitamin C transporters (SLC23A1 and SLC23A2). Results: 53% of subjects had adequate, 33% had suboptimal and 14% had deficient serum ascorbic acid. Subjects with deficiency had higher mean C-reactive protein, waist circumference, BMI and blood pressure than subjects with adequate serum ascorbic acid. The odds ratio (95% confidence interval) for serum ascorbic acid deficiency was 3.43 (2.14, 5.50) for subjects who did not meet the vitamin C recommendation compared to those who did. The corresponding odds ratios were 2.17 (1.10, 4.28) and 12.28 (4.26, 33.42) for individuals with the GSTT1 functional and null genotypes respectively (interaction p=0.01), and 2.29 (0.96, 5.45) and 4.03 (2.01, 8.09) for the GSTM1 functional and null genotypes (interaction p=0.04). These odds ratios were 4.77 (2.36, 9.65) for the Hp2-2 genotype, but 1.69 (0.80, 3.63) for carriers of the Hp1 allele (interaction p=0.02). Serum ascorbic acid concentrations (mean +/- SE) differed among SLC23A1 rs4257763 genotypes (GG: 24.4 +/- 1.3, GA: 26.8 +/- 1.1, AA: 29.7 +/- 1.4, p=0.002). Conclusions: Serum ascorbic acid deficiency is prevalent and associated with markers of chronic disease. Individuals with GST null or Hp2-2 genotypes had an increased risk of deficiency if they did not meet the recommendation for vitamin C, suggesting that GSTs and haptoglobin may spare ascorbic acid when dietary vitamin C is insufficient, thus protecting against serum ascorbic acid deficiency.

Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2012-08-29T21:11:40Z No. of bitstreams: 1 Silvana Sousa Paz Avaliação de marcadores....pdf: 756990 bytes, checksum: 5aac886be232eac44d86b25a30837ac4 (MD5) / Made available in DSpace on 2012-08-29T21:11:40Z (GMT). No. of bitstreams: 1 Silvana Sousa Paz Avaliação de marcadores....pdf: 756990 bytes, checksum: 5aac886be232eac44d86b25a30837ac4 (MD5) Previous issue date: 2012 / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil / As leucemias são malignidades hematopoiéticas, caracterizadas por subgrupos biologicamente distintos, sendo os tipos mais frequentes de cânceres em crianças e adolescentes. Polimorfismos em genes de enzimas que metabolizam xenobióticos podem estar relacionados com a inserções/deleções, polimorfismos de nucleotídeo simples (SNP’s) e variações no número de cópias e têm sido relacionados com a patogênese de algumas neoplasias hematológicas, como a leucemia linfóide aguda (LLA). O objetivo deste estudo foi o de determinar as frequências de polimorfismos em genes associados ao estresse oxidativo e metabolismo de xenobióticos (GSTT1, GSTM1, CYP2E1, NQO1 e MPO), em pacientes pediátricos com LLA, associando-as a aspectos clínicos e marcadores de evolução da doença. A casuística foi composta por 37 pacientes pediátricos seguidos na clínica ONCO e tratados pelo protocolo GBTLI-LLA 93. O perfil hematológico dos pacientes foi realizado ao diagnóstico e durante o tratamento e os polimorfismos gênicos foram investigados por reação da polimerase em cadeia - polimorfismo de tamanho de fragmento de restrição (PCR-RFLP) e por reação da polimerase em cadeia multiplex (PCR Multiplex). As análises estatísticas apresentaram significância para os valores de leucócitos totais nos D1 e D7 (p= 0,0016) e nos D1 e D14 (p= 0,0059); linfócitos nos D1 e D7 (p= 0,0088) e D1 e D14 (p= 0,0101); segmentados neutrófilos nos D1 e D7 (p= 0,0033) e D1 e D14 (p= 0,0252); blastos periféricos D1 e D7 (p< 0,0001) e D1 e D14 (p< 0,0001) e; para a contagem de blastos na medula óssea (MO) nos D1 e D15 (p<0,0001), D1 e D28 (p< 0,0001) e D15 e D28 (p= 0,0005). As frequências alélicas e genotípicas para os genes estudados estavam em equilíbrio de Hardy-Weinberg. A mutação do gene MPO foi associada a infiltração da MO (p= 0,0473) e presença de blastos no líquor (p= 0,0473). O polimorfismo do gene GSTT1 foi associado à contagem de leucócitos (p= 0,014) e plaquetas (p= 0,0034) no D1 e a contagem de leucócitos (p=0,037) e segmentados neutrófilos (p= 0,0008) no D7. A presença do polimorfismo no gene NQO1 foi associado à infiltração da MO (p= 0,0410) e a presença de blastos no líquor (p= 0,0410). Entretanto, o polimorfismo NQO1 apresentou associação com a presença de palidez (p=0,0096). Os dados encontrados corroboram em parte com dados encontrados na literatura, sendo necessária a realização de um estudo com numero maior de pacientes para confirmação dos achados relacionados aos genes investigados e a LLA. / Leukemia is characterized by biologically distinct subgroups and is the most frequent hematological malignity in childhood. Polymorphisms in genes of enzymes that metabolize xenobiotics may be related to insertions/ deletions, single nucleotide polymorphisms (SNP's) and gene copies variation and have been related to the pathogenesis of some hematologic malignancies, including acute lymphoblastic leukemia (ALL). The aim of this study was to investigate genes polymorphisms associated with the oxidative stress and xenobiotic metabolism (GSTT1, GSTM1, CYP2E1, NQO1 and MPO) in a group of childhood ALL patients, associating them with clinical evolution and prognostic markers. The casuistic was compound by 37 pediatric patients followed and treated at the clinic ONCO with the protocol GBTLI-LLA 93. The hematological profile of patients was performed at diagnosis and during treatment and gene polymorphisms were investigated by Polimerase Chain Reaction - Restriction Fragment Length Polymorfism (PCR-RFLP) and Polimerase Chain Reaction Multiplex (Multiplex PCR). Statistical analyses were significant for values of total leukocytes in D1 and D7 (p= 0.0016) and in D1 e D14 (p= 0.0059); lymphocytes in D1 and D7 (p= 0.0088), D1 and D14 (p= 0.0101); neutrophils in D1 and D7 (p= 0.0033), D1 and D14 (p= 0.0252). It was also find statistical significance at the number of peripheral blasts in D1 and D7 (p< 0.0001), D1 and D14 (p< 0.0001); the blast count in bone marrow (BM) in D1 and D15 (p<0.0001), D1 and D28 (p< 0.0001) and D15 and D28 (p= 0.0005). The allelic and genotypic frequencies of all gene polymorphism investigated were in Hardy-Weinberg equilibrium. The MPO gene mutation was associated with infiltration of the BM in D28 (p= 0.0473) and the presence of blasts in the CSF (p= 0.0473). The GSTT1 gene polymorphism was associated with leukocyte (p= 0.014) and platelet counts (p= 0.0034) in D1 and with leukocytes (p=0,037) and neutrophils counts (p= 0.0008) in D7. The NQO1 gene polymorphism presence was associated with BM infiltration at D28 (p= 0.0410) and the presence of blasts in the CSF (p= 0.0410). However, the NQO1 polymorphism was associated with the presence of pallor (p=0.0096). Result described here corroborated in part with previous described data, being necessary to carry out additional study with a larger number of patients to confirm the finding related to genes polymorphism investigated and the clinical evolution of ALL patients.