Objective To explore the anti-HBV activity of anodonta polysaccharides (AP) and dose-effect relationship in vitro.Methods HepG2.2.15 cells were cultured in vitro and incubated at 37℃ for nine days with AP at a dilution ratio of 1∶10.The expression of HBsAg and HBeAg were detected using ELISA and HBV-DNA copies were detected by real-time fluorescent quantitative PCR.Based on Thiele-type continued-fraction interpolation method,the anti-HBV activity of AP was studied,and the IC50 and the maximum inhibition rate were calculated.Results AP had significant inhibitory effect on the expression of HBsAg and HBeAg in HepG2.2.15 cells in vitro,as well as HBV DNA replication.By Thiele-type continued-fraction interpolation the equations of dose-effect relationship were obtained to determine the maximum inhibition rates of AP on HBeAg and HBsAg secretion being 47.7％ and 56.4％,and the IC50 inhibiting the expression of HBeAg being 143.7mg/L.AP was also able to inhibit HBV-DNA replication and the maximum inhibition rate was 17.8％ with the same method above.Conclusion Anodonta polysaccharides have anti-HBV activity.The thiele-type continued-fraction interpolation method is simple and practical and could be used as a new method for the analysis of drug activity.

Objective To determine the biological effectiveness of 125I radioactive seeds with continuous low dose rate radiation on the human esophageal cancer cell line KYSE150 in vitro and explore the underlying cellular mechanisms.Methods The cells were divided into three cell groups:control group,single dose radiation group (SDR) and 125I radioactive seeds with continuous low dose rate radiation group (125 I-CLDR).The KYSE150 cells were exposed to radiation of X-ray at a high dose rate of 1.052 Gy/min or 125I radioactive seeds at a low dose rate of 2.77 cGy/h.The responses of KYSE150 cells to two modes of irradiation were evaluated by the colony-forming assay,cell apoptosis as well as cell cycle analysis.Furthermore,the expression levels of γ-H2AX and Bax were detected by Western blot.Results KYSE150 cells were more radiosensitive to 125I-CLDR than SDR.The relative biological effectiveness (RBE) for 125I-CLDR related to SDR was 1.56.Compared with SDR,125I-CLDR yielded more proportions of the early and late apoptosis rate (t =4.07,11.08,P ＜0.05) as well as cells at G2/M phase (t =11.25,P ＜0.05).Moreover,γ-H2AX and Bax expression levels in 125I-CLDR significantly increased compared with SDR.Conclusions Compared with the high dose rate X-ray radiation,the continuous low dose rate radiation of 125I radioactive seeds had stronger inhibition effect on KYSE150 esophageal cancer cells by impairing clonogenic capacity,inducing apoptosis and G2/M cell cycle arrest,and increasing radiosensitivity.

Using the animal model of acute myocardial infarction of rabbit after left coronary artery ligation, the authors studied the reltionship between the change of myocardial K~+/Na~+ ,Mg~(2+)/Ca~(2+), and Zn~(2+)/Cu~(2+) ratio and the time after acute myocardial infarction. The results demonstrated that. (1)the K+/Na~+ and Mg~(2+)/Ca~(2+)ratio dropped with prolongation of time myocardial ischemia. There was significant (P0.05)difference of Zn~(2+)/Cu~(2+) ratio between the experimental groups and the control group, but Zn~(2+)/Cu~(2+) ratio showed a tendency of dropping with prolongation of time of ischemia in the experimental group. At 120 min of myocardial ischemia,the Zn~(2+)/Cu~(2+) ratio was abour 1/2 as those at 15min, 30min, and 60min(P