ABSTRACT
Resumo Fundamento Tem sido demonstrado que um aumento dos níveis séricos de PON1 é protetor contra vários distúrbios. Foi relatado que vários polimorfismos de nucleotídeo único (SNPs, single nucleotide polymorphisms ) do gene PON1 estão associados a níveis e atividade de proteínas enzimáticas séricas. Objetivos Investigar a associação de SNPs do PON1 e atividade da paraoxonase sérica com a doença arterial coronariana (DAC). Métodos Foram estudados 601 pacientes não relacionados submetidos à angiografia coronária, incluindo aqueles com estenose >50% (N=266) e aqueles com estenose <30% (N=335). Os SNPs rs662 e rs840560 do gene da paraoxonase foram determinados utilizando o método ARMS-PCR e o SNP rs705379 foi genotipado utilizando análise de PCR-RFLP. A atividade da paraoxonase sérica foi medida utilizando paraoxon como substrato. O valor de p<0,05 foi considerado significante. Resultados A atividade da paraoxonase sérica não foi significativamente diferente entre os grupos de estudo. Após ajuste para idade, sexo, hipertensão, diabetes mellitus e dislipidemia, o genótipo GG e o modelo codominante de rs662 foram positivamente associados a uma angiografia positiva (respectivamente, OR = 2,424, IC 95% [1,123-5,233], p <0,05, OR = 1,663, IC 95% [1,086-2,547]). A atividade da paraoxonase sérica foi significativamente maior no alelo G e variante GG do polimorfismo rs662, alelo A e variante AA de rs854560 e alelo C e variante CC de rs705379. A análise de haplótipos mostrou que o haplótipo ATC foi significativamente mais prevalente no grupo com angiografia negativa. A análise entre os grupos indicou que o alelo A de rs662 foi significativamente associado à menor atividade da paraoxonase no grupo com angiografia positiva (p=0,019). Conclusões A presença do alelo G do polimorfismo de nucleotídeo único rs662 está independentemente associada ao aumento do risco de DAC.
Abstract Background It has been shown that increased serum PON1 levels are protective against several disorders. Several single nucleotide polymorphisms (SNPs) of the PON1 gene have been reported to be associated with serum enzyme protein levels and activity. Objective To investigate the association of SNPs of PON1 and serum paraoxonase activity with coronary artery disease (CAD). Methods A total of 601 unrelated patients who underwent coronary angiography including those who had >50% stenosis (N=266) and those with <30% stenosis (N=335) were studied. The Paraoxonase gene rs662 and rs840560 SNPs were determined using the ARMS-PCR method and the rs705379 SNP was genotyped using PCR-RFLP analysis. Serum paraoxonase activity was measured using paraoxon as a substrate. A p value of p<0.05 was considered as significant. Results Serum paraoxonase activity was not significantly different between the study groups. After adjustment for age, sex, hypertension, diabetes mellitus and dyslipidemia, the GG genotype and co-dominant model of rs662 was positively associated with a positive angiogram (respectively, OR=2.424, 95%CI [1.123-5.233], p<0.05, OR=1.663, 95%CI [1.086-2.547]). Serum paraoxonase activity was significantly higher in the G allele and GG variant of rs662, A allele and AA variant of rs854560 and C allele and CC variant of rs705379. The haplotype analysis has shown that the ATC haplotype was significantly more prevalent among the angiogram negative group. The analysis between groups indicated that the A allele of rs662 was significantly associated with lower paraoxonase activity in the positive angiogram group (p=0.019). Conclusions The presence of the G allele of the rs662 single nucleotide polymorphism is independently associated to increased risk of CAD.
ABSTRACT
Background and Objectives : All elements existing in orthodontic alloys can be released to the oral cavity as corrosion products; therefore, they can accumulate in body tissues after systemic absorption. Among body tissues that can be evaluated for systemic absorption of nickel, in this study we used hair strands, because if nickel is absorbed systematically, it would accumulate in these strands over time. Furthermore, hair sampling is a non-invasive method, so the main aim of this study was the evaluation of nickel ions release into the hair strands of fixed orthodontic patients compared with the control group in a 4-month duration. Materials and Methods: In this clinical trial, the test group included 24 female patients between 12-20 years of age that were going to begin fixed orthodontic treatment. The control group consisted of their sisters in the same age range, who volunteered to participate in this study. Initial hair samples were taken from both groups at the beginning the study and immediately before setting up the fixed appliances in test group. The samples were taken from three different scalp sites including; frontal, vertex, and occipital areas. After 16 weeks, hair samples were taken from approximately the same scalp areas in both the groups. The samples were analyzed by atomic absorption spectrophotometer and data analyzed by Mann-Whitney test. Results: This study showed that there were significant differences in nickel levels before and after study for case (P = 0.004) and control groups (P = 0.012). The mean nickel concentration after four months was 0.382 ± 0.36 μg/g for controls and 0.673 ± 0.38 μg/g for the case group, which was significantly different (P = 0.002). Conclusion: The hair nickel concentrations significantly increased after insertion of fixed orthodontic appliances as compared with the control group.