A study on the ideal method for cryopreserving human fetal islet tissues was carried out. The viability and the secretory function of fetal islets cryopreserved with 1.0,1.5,and 2.0 mol/L DMSO and with balancing for 30 and 60 minutes under room temperature and 4℃ as well as the influence of different cooling rates were compared. The results of the study showed that the viability of islets cryopreserved with slow cooling rate at 0.3℃/min, was the best and the insulin content of the media and the amount of insulin secretion of the insulin releasing test were significantly higher than those of the control group.In addition,morphologic examination with HE and immunocytochemical staining showed that the morphology of the islets cryopreserved with 1.5 mol/L DMSO,balancing under 4℃ for 60 minutes and slow cooling rate was much better,i.e.the acinar cells appeared to be degenerated and necrosed,clusters of islets with insulin-positive cells and the ductule-like cells were clearly visible.

In recent 10 years, using radiofrequency catheter ablation, our medical center has treated 4865 cases of paroxysmal supraventricular tachycardia (PSVT). To improve clinical practice, a retrospective analysis of this group was made. In this group, 2092 cases were atrioventricular reentry tachycardia (AVRT), including 1415 left accesory pathway and 677 right accesory pathway, and 2773 cases were atrioventricular nodal reentry tachycardia (AVNRT). The total success rate of radiofrequency treatment is 99.71%; the recurrence rate after half a year 1.73%; the total complication rate 1.25%. In conclusion, radiofrequency ablation is a safe and effective treatment for tachycardia with high rate of success and low rate of complication.
Adult ; Catheter Ablation ; Female ; Humans ; Male ; Retrospective Studies ; Tachycardia, Paroxysmal ; surgery ; Tachycardia, Supraventricular ; surgery ; Young Adult

OBJECTIVE: To determine the effect and molecular mechanism of DNA damage caused by suicide gene therapy system HSV-TK/GCV under Tet-On regulation in human breast cancer cell line MCF-7 infected by recombinant adeno-associated virus (rAAV). METHODS: We used comet assay to detect the effect of HSV-TK/GCV suicide gene regulation system on MCF-7 DNA damage, and analyzed the expression change of relative DNA damage response active genes and proteins with RT-PCR and Western blot. RESULTS: Compared with other control groups, the comet assay showed that MCF-7 cells with HSV-TK/GCV treatment had obvious comet tails, and the expression level of DNA damage response active genes and proteins changed obviously in the HSV-TK/GCV treatment group,such as ATM, p53 and p27,but CyclinE and CDK2 did not change. CONCLUSION DNA damage on MCF-7 cells is resulted from HSV-TK/GCV in suicide gene therapy system through a p53-dependent signal pathway, causing cell cycle arrest and cell death.
Breast Neoplasms ; genetics ; pathology ; therapy ; DNA Damage ; Dependovirus ; genetics ; Female ; Ganciclovir ; metabolism ; pharmacology ; Gene Expression Regulation, Neoplastic ; Genes, Transgenic, Suicide ; genetics ; Genetic Therapy ; Humans ; MCF-7 Cells ; Recombinant Fusion Proteins ; genetics ; metabolism ; Simplexvirus ; enzymology ; Thymidine Kinase ; genetics