RESUMO
BACKGROUND: X-ray repair cross-complementing group 1 (XRCC1) gene is a DNA repair gene and its non-synonymous single nucleotide polymorphisms (SNP) may influence DNA repair capacity which has been considered as a modifying risk factor for cancer development. METHODS: A case-control study was conducted to investigate impact of three frequently studied polymorphisms (Arg194Trp, Arg280His and Arg399Gln) on developing differentiated thyroid carcinoma (DTC). RESULTS: Increased risks for DTC were shown in homozygous (odds ratio [OR]: 3.66, 95% confidence interval [CI]: 0.38-35.60) and in dominant trait (OR: 1.22, 95% CI: 1.64-2.32) of Arg194Trp genotype. Also, for Arg280His genotype, an increased risk for DTC was shown in dominant trait (OR: 1.42, 95% confidence interval [CI]: 0.76-2.68), while a mildly reduction of risk for DTC (OR: 0.77, 95% [CI]: 0.50-1.17) was estimated in dominant Gln genotype of Arg399Gln. Considering combinatory effects of Arg194Trp and Arg280His genotypes on DTC, the calculated OR and 95% CI for being heterozygous for one of Arg194Trp or Arg280His genotypes were 1.57 and 0.90-2.74, respectively. CONCLUSION: Genotyping of codons 194, 280 and 399 in XRCC1 gene may use in risk assessment of DTC.
Assuntos
Diferenciação Celular , Teste de Complementação Genética , Polimorfismo de Nucleotídeo Único , Neoplasias da Glândula Tireoide/epidemiologia , Arginina/genética , Sequência de Bases , Estudos de Casos e Controles , Primers do DNA , Feminino , Glicina/genética , Histidina/genética , Humanos , Irã (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Fatores de Risco , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia , Triptofano/genéticaRESUMO
BACKGROUND: Methylenetetrahydrofolate reductase (MTHFR) involves in folic acid metabolism which influences DNA methylation. A single nucleotide polymorphism (SNP) called 677CâT in MTHFR gene causes producing a thermolabile enzyme with reducing function and eventually defects DNA methylation. To determine association between germ-line polymorphism in MTHFR gene with differentiated thyroid carcinoma (DTC), this preliminary study was designed. METHODS: This was a case-control study of 154 DTC patients and 198 cancer free individuals. Genotyping was performed by a multiplex PCR method and the frequencies of the 677CâT SNP in cases and controls were compared. The risk estimation was done by multivariate logistic regression analysis. RESULTS: Compared to CC genotype, an increased risk of DTC for the 677CâT homozygous genotype was demonstrated (odds ratio [OR]: 2.08, 95% confidence interval [CI]: 0.82-5.25). Also, multivariate analysis demonstrated an increased risk of DTC in recessive fashion (TT vs. CC or CT) (OR: 2.38, 95% CI: 0.97-5.82). CONCLUSION: The MTHFR 677CâT homozygous variant allele may be associated with increased risk of DTC.
Assuntos
Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo de Nucleotídeo Único/genética , Neoplasias da Glândula Tireoide/genética , Estudos de Casos e Controles , Diferenciação Celular , Feminino , Genótipo , Homozigoto , Humanos , Irã (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Neoplasias da Glândula Tireoide/epidemiologiaRESUMO
The diagnosis of the different forms of thalassemia is one of the important applications of analysis of globin chains. These analyses are done by high performance liquid chromatography (HPLC) using a MONO-S cation exchange column and ether is used for washing the globin powder in the final step. The presence of peroxide impurities in ether could change the structure of the globin chains. In the chromatograms, these modified globins appear as separated peaks next to the unmodified globin peaks. In these cases, the alpha/beta ratio exceed by artifact the correct value. Our study demonstrates that diagnostic centers should ensure that the ether they use is pure.
