Impact of Glutathione S-Transferase M1 and T1 Gene Polymorphisms on the Smoking-Related Coronary Artery Disease

Glutathione S-transferase (GST) plays a key role in the detoxification of xenobiotic atherogen generated by smoking. To analyze the effect of GSTM1/T1 gene polymorphisms on the development of smoking-related coronary artery disease (CAD), 775 Korean patients who underwent coronary angiography were enrolled. The subjects were classified by luminal diameter stenosis into group A (>50%), B (20-50%), or C (<20%). GSTM1 and GSTT1 gene polymorphisms were analyzed using multiplex polymerase chain reaction (PCR) for GSTM1/T1 genes and CYP1A1 gene for internal control. Of 775 subjects, 403 patients belonged to group A. They had higher risk factors for CAD than group B (N=260) and group C (N=112). The genotype frequencies of null GSTM1 and GSTT1 showed no significant differences among 3 groups. Considering the effect of GSTM1 gene polymorphisms on the smoking-related CAD, smokers with GSTM1 null genotype had more increased risk for CAD than non-smoker with GSTM1 positive genotype (odds ratios [OR], 2.07, confidence interval [CI], 1.06-4.07). Also the effect of GSTT1 gene polymorphism on smoking-related CAD showed the same tendency as GSTM1 gene (OR, 2.00, CI, 1.05-3.84). This effect of GSTM1/T1 null genotype on smoking-related CAD was augmented when both gene polymorphisms were considered simultaneously (OR, 2.76, CI, 1.17-6.52). We concluded that GSTM1/T1 null genotype contributed to the pathogenesis of smoking-related CAD to some degree

A theoretical and experimental study on cake filtration with sedimentation

Abstract−Sedimentation occurs in almost all cake filtration. To study the role of sedimentation during filtration, filtration-permeations were carried out for suspensions of various concentrations. The average specific cake resistances calculated by the traditional method using the filtration data and initial concentration of suspension give different values according to the suspension concentrations. But the average specific cake resistances from the permeation period show almost the same values in spite of the various suspension concentrations. To exclude the influence of sedimentation, a complete sedimentation was performed before beginning filtration and then filtration-permeation of the sediment was performed. The average specific cake resistance from the filtration period calculated with the mass fraction of sediment and that from the permeation period coincide very well. These values also coincide well with the former average specific resistances during permeation within the experimental error limits. It can be concluded that the average specific cake resistances by permeation operation give almost the same values for various concentrations of suspension. A new definition of a cake and a new concept of the filter medium R m are proposed based on the analysis of experimental results