Single nucleotide polymorphism in DNA methyltransferase 3B promoter and its association with gastric cardiac adenocarcinoma in North China

AIM: To investigate the association between single nucleotide polymorphism (SNP)in promoter of the DNA methyltransferase 3B (DNNT3B) gene and risk for development and lymphatic metastasis of gastric cardiac adenocarcinoma (GCA).METHODS: The hospital based case-control study included 212 GCA patients and 294 control subjects without overt cancer. The DNMT3B SNP was genotyped by PCR and restriction fragment length polymorphism (RFLP) analysis. RESULTS: The C/C genotype was not detected in both GCA patients and controls. In control subjects, the frequency of T/T and C/T genotypes was 94.9% and 5.1% respectively,and that of T and C alleles was 97.4% and 2.6%, respectively.The genotype and allelotype distribution in the GCA patients was not significantly different from that in controls (P = 0.34 and 0.33, respectively). When stratified by smoking status and family history of upper gastrointestinal cancer, significant difference in the genotype distribution was not observed between GCA patients and controls. The distribution of DNMT3Bgenotypes in GCA patients with or without lymphatic metastasis did not show significant difference (P = 0.42). CONCLUSION: The distribution of DNMT3BSNP in North China is distinct from that in Caucasians. Although this SNP has been associated with susceptibility to lung, head, neck and breast cancer, it may not be used as a stratification marker to predict susceptibility and lymphatic metastasis of GCA, at least in the population of North China.

No association of the matrix metalloproteinase 1 promoter polymorphism with susceptibility to esophageal squamous cell carcinoma and gastric cardiac adenocarcinoma in northern China

AIM: To investigate association of the 2G or 1G single nudeotide polymorphism (SNP)in matrix metalloproteinase 11(MMP1)promoter with susceptibility to esophageal squam-ous cell carcinoma (ESCC) and gastric cardiac adenocarcinoma (GCA) in a population of North China.METHODS: MMP1 promoter SNP was genotyped by polymerase-chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis in 417 cancer patients (234ESCC and 183 GCA) and 350 healthy controls.RESULTS: The genotype frequencies of the MMP1promoter SNP in healthy controls were 55.4% (2G/2G),30% (1G/2G) and 14.6% (1G/1G), respectively. The genotype and allelotype distribution in ESCC and GCA patients was not significantly different from that in healthy controls (all Pvalues were above 0.05). Compared with the 1G/1G genotype, neither the 2G/2G nor in combination with the 1G/2G genotype significantly modified the risk of developing ESCC and GCA, the adjusted odds ratio was 1.28 (95%CI = 0.78-2.09), 1.23 (95%CI = 0.38-2.05)in ESCC and 1.39 (95%CI = 0.80-2.41), 1.34 (95%CI =0.74-2.40) in GCA, respectively. When stratified by smoking status and family history of upper gastrointestinal cancer, the 2G/2G genotype alone or in combination with the 1G/2G genotype also did not show any significant influence on the risk of ESCC and GCA development. In addition, influence of the MMP1 SNP on lymphatic metastasis in ESCC and GCA was also not obs-erved.CONCLUSION: The 2G or 1G SNP in the MMP1 promoter might not modify the risk of ESCC and GCA development and might not be used as a stratification marker to predict the potential of lymphatic metastasis in these two tumor types.

Epoxide hydrolase Tyr113 His polymorphism is not associated with susceptibility to esophageal squamous cell carcinoma in population of North China

AIM: To investigate the possible association of microsomal epoxide hydrolase ( mEH) Tyr113 His polymorphism with susceptibility to esophageal squamous cell carcinoma (ESCC) in a population of North China.METHODS: The mEH-Tyr113 His genotypes were determined by polymerase-chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis in 257 patients with esophageal squamous cell carcinoma (ESCC) and 252 healthy subjects as a control group.RESULTS: The frequencies for Tyr and His alleles were 44.2 %, 55.8 % in ESCC patients, and 44.0 % and 56.0 %in healthy subjects, respectively. No statistic difference in allele distribution was observed between ESCC patients and controls (x2=0.008, P=0.929). The overall genotype distribution difference was not observed between cancer cases and controls (x2=2.116, P=-0.347). Compared with Tyr/Tyr genotype, neither His/His genotype nor in combination with Tyr/His genotype significantly modified the risk of the development of ESCC, the adjusted odds ratio was 1.076 (95 % CI=0.850-1.361) and 0.756 (95 % CI=0.493-1.157),respectively. When stratified for sex, age, smoking status and family history of upper gastrointestinal cancer, His/His genotype alone or in combination with Tyr/His genotype also did not show any significant influence on the risk of developing ESCC.CONCLUSION: MEH Tyr113His polymorphism may not be used as a stratification marker in screening individuals at a high risk of ESCC.

Unitary Bases and Noncommutative Wavelets

In this paper, we construct new unitary bases in noncommutative wavelets.

Perturbation spectrum method for seismic analysis of non-classically damped systems

Fundamental principles from structural dynamics,random theory and perturbation methods are adopted to develop a new response spectrum combination rule for the seismic analysis of non-classically damped systems,such as structure-damper systems. The approach,which is named the perturbation spectrum method,can provide a more accurate evaluation of a non-classically damped system's mean peak response in terms of the ground response spectrum. To account for the effect of non-classical damping,all elements are included in the proposed method for seismic analysis of structure,which is usually ap-proximated by ignoring the off-diagonal elements of the modal damping matrix. Moreover,as has been adopted in the traditional Complete Quadratic Combination (CQC) method,the white noise model is also used to simplify the expressions of perturbation correlation coefficients. Finally,numerical work is performed to examine the accuracy of the proposed method by comparing the approximate results with exact ones and to demonstrate the importance of the neglected off-diagonal elements of the modal damping matrix. In the examined cases,the proposed method shows good agreement with direct time-history integration. Also,the perturbation spectrum method leads to a more efficient and economical calculation by avoiding the integral and complex operation.