Objective To analyse the effects of high insulin on the expression and function of P-glycoprotein (P-gp), and preliminarily investigate the influence of insulin on chemotherapeutic sensitivity in MCF-7/ADR cells. Methods MCF-7/ADR cells were cultured with different concentrations of insulin(0.001, 0.005, 0.01, 0.05 and 0.1μmol/L). Real-time PCR was used to detect the expression of P-gp mRNA. Western blot assay was used to detect the expression level of P-gp. Rhodamine 123 was used to detect the efflux function level of P-gp. Cell viability and chemotherapeutic sensitivity were detected by MTT assay. Results High concentration of insulin (0.1 μmol/L) promoted the proliferation of MCF-7/ADR cells. The concentration of insulin (0.05 and 0.1 μmol/L) accelerated P-gp mRNA and protein expression, which also augmented the efflux function of P-glycoprotein and reduced the chemotherapeutic sensitivity to epirubicin. Conclusion High concentration of insulin may influence the drug resistance of breast cancer cells by promoting the expression and function of P-glycoprotein of MCF-7/ADR cells.

Objective To review and summarize the experiences of transcatheter closure of left ventricular-right atrium communication,and discuss the feasibility of interventional therapy for this kind of cardiac abnormalitis.Methods 22 patients who suffered from left ventricular-right atrium communication underwent transcatheter interventional therapy with ventricular septal defect(VSD) occluder.The operating procedures were performed as like as the transcatheter closure of VSD:established the pathway from femoral artery to femoral vein through left ventricle,VSD,right atrium (or from left ventricle to right atrial through the communication) and inferior vena cava,then inserted the polysheath from femoral vein,introduced by the pathway to left ventricle,and implanted VSD occluder through the polysheath to close the shunt.Results The operation succeeded in 21 patients.The cardiac murmur was disappeared in all patients,and there was no residual shunt or aortic regurgitation that conformed by postoperative ventriculography and echocardiography in follow up phase,and the tricuspid regurgitation was lessened than preoperative.The operation abort in 1 patient because of aortic regurgitation after implanting occluder.Conclusions Transcatheter closure of left ventricular-right atrium communication is feasible as the selected occluder is accordant,and atrioventricular block,aortic regurgitation and tricuspid regurgitation can be avoided.