OBJECTIVETo investigate the apoptosis of NK cells induced by the erythroleukemia cell line K562 in vitro.

METHODSPrimary NK cells isolated from the peripheral blood of healthy donors by magnetic-activated cell sorting were cultured with stem cell medium containing recombinant human interleukin-2 (rhIL-2). The NK cells and K562 cells were mixed and co-cultured at different E:T ratios for different time lengths. The apoptosis of NK cells and K562 cells were detected using PE-AnnexinV/7-AAD labeling and flow cytometry.

RESULTSThe purity of isolated NK cells reached (93.99∓4.22)%. At the same E: T ratio, the apoptotic rate of NK cells induced by K562 cells increased significantly with time. As the E:T ratio reduced, the apoptotic rate of the NK cells increased and their cytotoxic activity against K562 cells was attenuated.

CONCLUSIONK562 cells can induce the apoptosis of activated NK cells, which is one of the probable mechanisms of immune escape of tumors.

Apoptosis ; Cytotoxicity, Immunologic ; Humans ; K562 Cells ; Killer Cells, Natural ; cytology ; immunology ; Tumor Escape

In order to study effects of ginseng on the metabolism of drug belong to CYP3A4 substrate, screening of pregnane X receptor activation from ginsenosides was performed by reporter assay. Based on PXR-CYP3A stable translation cell lines, 13 ginsenosides were screened for pregnane X receptor activation by reporter assays, and RIF as the positive control. The effect of ginsenosides Rg1 onCYP3A4 mRNA expression was also investigated by RT-PCR. The PXR-CYP3A stable translation cell lines had good response to RIF, and the EC50 is 2.51 micro mol x L(-1). When the condition of final concentration was 10 micromol x L(-1), ginsenoside F2 and protopanaxatriol had moderate inductive effects on PXR. Panaxotriol, Rg2, pseudoginsenoside F11, Rg1, ginsenoside and Rb3 had inhibitory effects on PXR. Ginsenoside Rf1, Rg3, Rh2 and protopanaxdiol had no obvious effects on PXR. Rg1 down-regulated CYP3A4 mRNA expression in a concentration-dependent manner. Activation of pregnane X receptor by ginsenosides may influence the metabolism of drug belong to CYP3A4 substrate, and cause ginseng-drug interactions.

Objective To explore the causes of persistent abnormal muscle response (AMR) after microvascular decompression (MVD) for hemifacial spasm (HFS) and the clinical outcomes of these patients.Methods MVD was performed under intraoperative electrophysiological monitoring of AMR in 372 HFS patients in 2014.Before MVD,the characteristic AMR of HFS was recorded in 326 patients.The patients were divided into two groups based on whether AMR disappeared or persisted following MVD;21 patients showed persistent AMR after successful MVD while AMR disappeared after decompression in the other 305 patients.The clinical features,treatment efficacy and postoperative complications were compared between these two groups.Results Gender,side of depression and mean age between the two groups showed no significant differences (P＞0.05).The immediate postoperative cure rate of the AMR disappeared group (88.9％) was significantly higher than that in the AMR persisted group (28.6％,P＜0.05).The follow-up cure rate showed no significant difference between the two groups (P＞0.05),and the postoperative and follow-up complications showed no significant differences (P＞0.05).Conclusion The long duration of HFS patients may be responsible for persistent AMR after successful decompression,and it is more likely for these patients to get delayed cured;their long-term outcomes showed no difference as compared with those in patients with disappeared AMR after MVD.