Meta-Analysis of Smoking and the Risk of Gastric Cancer among the Chinese Population

OBJECTIVE To reevaluate the effect of tobacco smoking on therisk of developing gastric cancer among the Chinese population.METHODS Thirty articles from the literature both in Chineseand English from January,1988 to present were identified andfrom which adjusted odd ratios(ORs)or relative risks(RRs)werecombined by meta-analysis.Generalized least squares(GLS)fortrend estimation of summarized dose-response data was carriedout.All the analyses were performed using software of STATAversion 10.0.RESULTS Comparing current smokers with subjects who havenever smoked,the summary effect values on gastric cancer witha 95% confidence interval(CI)were 1.67(1.43-1.96)for case-control studies and 1.52(1.17-1.96)for cohort studies,respectively.The combined effect values with a 95%CI for the comparison ofsmoking quantity of current smokers with the referent groupwere 1.41(1.15-1.72)for case-control studies and 1.24(1.02-1.52)for cohort studies,respectively.The combined effect values witha 95%CI for the comparison of accumulative years smoked ofcurrent smokers with the referent group were 1.07(0.89-1.28)for case-control studies and 1.28(0.95-1.74)for cohort studies,respectively.Dose-response meta-analysis showed that the gastriccancer risk will increase 50%(OR=1.50,95%CI:1.34-1.67)witheach 20 cigarette per day increment and increase 14%(OR=1.14,95%CI:1.10-1.18)with each 10 year increment of smoking.CONCLUSION The gastric cancer risk among the Chinesepopulation is significantly associated with tobacco smoking andthe smoking quantity per day.Smoking cessation should be morestrongly advocated.

Lactoferrin improves hepatic pyroptosis in mice after irradiation

Objective:To investigate the effects of lactoferrin(Lf)on hepatic pyroptosis(an inflammatory form of programmed cell death)in mice exposed to radiation.Methods:A total of thirty-six BALB/c male mice were randomly divided into four groups,namely the control group,5 Gy group,5 Gyþ2 mg Lf group,and 5 Gyþ4 mg Lf group.The mice were administered whole-body ionizing radiation using a PRIMUS accelerator,with a single dose of 5 Gy and an absorbed dose rate of 2.0 Gy/min at a source-skin distance of 100 cm.Lf solution was intraperitoneally injected into the mice 2 h before and per day after radiation.The mice were sacrificed 1,3,and 9 d after radiation,and their livers were used for histopathologic examination,immunohistochemistry analysis,and Western blot analysis for absent in melanoma 2(AIM2)inflammasome pathway.Results:Histopathologic examination showed the disorder of the hepatocellular structure and the accumulation of inflammatory cells after radiation.Lf intervention inhibited hepatocellular proliferation and decreased the infiltration of inflammatory cells.Immunohistochemistry analysis indicated that AIM2 overexpression was significantly attenuated by 4 mg of Lf(t=3.065,P<0.05)3 d after radiation and by 2 mg and 4 mg of Lf(t=4.032,t=2.786,P<0.05)9 d after radiation.Western blot analysis showed that Lf downregulated the hepatic overexpression of AIM2,apoptosis-associated speck-like protein containing a caspase activation and recruitment domain(ASC),IL-1β,and IL-18.2 mg of Lf significantly downregulated the abovementioned protein expression 3 d(t=7.934,4.092,5.193,2.916,P<0.05)and 9 d after radiation(t=5.016,3.882,9.528,P<0.05 for AIM2,ASC,IL-1β).Conclusions:Lf intervention suppressed the hepatic pyroptosis in mice exposed to ionizing radiation by downregulating the protein expression of AIM2 inflammasome.