Association Between Nitrite and Nitrate Intake and Risk of Gastric Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND Studies have shown inconsistent associations of nitrite and nitrate intake with the risk of gastric cancer or its associated mortality. We performed a meta-analysis of observational studies to evaluate the correlation of nitrite and nitrate intake with the risk of gastric cancer. MATERIAL AND METHODS We searched for studies reporting effect estimates and 95% confidence intervals (CIs) of gastric cancer in PubMed, EMBASE, and the Cochrane Library through November 2018. The summary results of the included studies were pooled using a random-effects model. RESULTS Eighteen case-control and 6 prospective cohort studies recruiting 800 321 participants were included in this study. The summary results indicated that the highest (odds ratio [OR], 1.27; 95%CI, 1.03-1.55; P=0.022) or moderate (OR: 1.12; 95%CI, 1.01-1.26; P=0.037) nitrite intake were associated with a higher risk of gastric cancer. However, we noted that high (OR, 0.81; 95%CI, 0.68-0.97; P=0.021) or moderate (OR, 0.86; 95%CI, 0.75-0.99; P=0.036) nitrate intakes were associated with a reduced risk of gastric cancer. These associations differed when stratified by publication year, study design, country, the percentage of male participants, assessment of exposure, adjusted model, and study quality. CONCLUSIONS High or moderate nitrite intake was associated with higher risk of gastric cancer, whereas high or moderate nitrate intake was correlated with lower risk of gastric cancer.

Polymorphic distribution and forensic effectiveness study of eight miniSTR in Chinese Uyghur ethnic group.

We obtained the allelic frequencies and forensic efficiency data for eight mini short tandem repeat loci including Penta E, D12S391, D6S1043, D2S1338, D19S433, CSF1PO, Penta D and D19S253 loci from a sample of 128 unrelated Uyghur individuals from China. The amplification products of the eight STR loci are <240 bp in size. A total of 94 alleles were observed and the corresponding allelic frequencies ranged from 0.0039 to 0.3438 in the present study. Observed genotype distributions for each locus do not show deviations from Hardy-Weinberg equilibrium expectations. The combined power of discrimination, combined power of exclusion and combined matching probability of the eight STR loci equaled to 0.999999999963373, 0.9997770 and 3.6627 × 10(-11), respectively. Because of the small fragment length of PCR products and the high degree of polymorphisms, the eight STR loci are highly beneficial for the forensic analysis of degraded DNA samples which are commonly observed in forensic cases. The STR data of the Uyghur group were compared with the previously published population STR data of other groups from different ethnic or areas, and significant differences were observed among these groups at some loci.