RESUMO
Human colorectal cancer (CRC) is a major worldwide health concern, and its development has been shown to be associated with alcohol intake. We carried out a study to investigate the effect of the ADH1B Arg47His and ALDH2 Glu487Lys genetic polymorphisms and their interaction with alcohol consumption on development of CRC. Between March 2013 and May 2015, a total of 274 CRC patients and 358 healthy controls were recruited. Genotyping of sequence variations was performed using the polymerase chain reaction-restriction fragment length polymorphism method. Under a co-dominant model, individuals with the ADH1B Arg47His AA genotype showed increased CRC risk compared to those carrying the GG genotype, with an adjusted odds ratio (and 95% confidence interval) of 3.37 (2.00-5.70). Moreover, under dominant and recessive models, ADH1B Arg47His variant genotypes were associated with greater susceptibility to CRC when compared with the wild-type sequence. Both polymorphisms examined were positively associated with alcohol consumption in a Spearman correlation analysis of CRC risk. In conclusion, our study suggests that the ADH1B Arg47His polymorphism, but not the ALDH2 Glu487Lys variation, may influence development of CRC in the Chinese population.
Assuntos
Álcool Desidrogenase/genética , Aldeído-Desidrogenase Mitocondrial/genética , Povo Asiático/genética , Neoplasias Colorretais/genética , Interação Gene-Ambiente , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único/genética , Estudos de Casos e Controles , Demografia , Feminino , Estudos de Associação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
Because spin-flip length is longer than the electron mean-free path in a metal, past studies of spin-flip scattering are limited to the diffusive regime. We propose to use a magnetic double barrier tunnel junction to study spin-flip scattering in the nanometer sized spacer layer near the ballistic limit. We extract the voltage and temperature dependence of the spin-flip conductance Gs in the spacer layer from magnetoresistance measurements. In addition to spin scattering information including the mean-free path (70 nm) and the spin-flip length (1.0-2.6 microm) at 4.2 K, this technique also yields information on the density of states and quantum well resonance in the spacer layer.
