ABSTRACT
Objective To study the effects of schisandrin B (Sch B) on the apoptosis of human breast cancer MDA-MB-231 cells and its mechanism. Methods Cell counting reagent (CCK-8) was used to detect the effect of Sch B on the survival rate of MDA-MB-231 cells. MDA-MB-231 cells were treated with Sch B (10, 20, 40 μmol/L) for 24 hours. The cell death was detected by Annexin V-FITC/PI. The levels of intracellular reactive oxygen species (ROS) were detected by DCFA-DA fluorescent probe. Apoptosis and the expression of endoplasmic reticulum stress related proteins (Bcl-2、Bax、CHOP、GPR78、PERK、p-PERK、p-eIF2α、eIF2) were detected by Western blot. Results Compared with the blank group, the cell survival rate decreased significantly (P<0.01) with the increase of Sch B concentration, and its IC50 was 19.16 μmol/L. Compared with the control group, Sch B groups (10, 20, 40 μmol/L) inhibited cell clone formation in a dose-dependent manner (P<0.05). Sch B groups (10, 20, 40 μmol/L) induced apoptosis (P<0.05), significantly reduced the expression of anti-apoptotic protein Bcl-2 and significantly increased the expression of pro-apoptotic protein Bax (P<0.05). Sch B groups (10, 20, 40 μmol/L) significantly increased the level of intracellular ROS in a dose-dependent manner (P<0.05). Sch B groups (10, 20, 40 μmol/L) stimulated endoplasmic reticulum stress and increased the expressions of endoplasmic reticulum stress-related proteins CHOP, GPR78 and p-eIF2α in a dose-dependent manner (P<0.05). Conclusion Sch B induces apoptosis of MDA-MB-231 cells through ROS mediated endoplasmic reticulum stress.
ABSTRACT
Objective To establish a rapid,specific and sensitive TaqMan real-time fluorescence quantitative PCR assay for detection of murine polyomavirus ( MPyV) .Methods The specific primers and TaqMan probe were designed based on genome sequence of MPyV.The primers amplified a 69 bp fragment.After optimizing the reaction system and reaction condition, the standard curve was plotted by detecting recombinant plasmid standards.The specificity, sensitivity and reproducibility of this method were evaluated.In addition, samples of lungs, spleens and feces obtained from experimentally infected mice and 86 clinical samples were used to validate the efficacy of this real-time PCR assay.Results The specificity assay showed that this assay could specifically detect MPyV and the sensitivity for MPyV was about 100 copies/well.The coefficients of variation ( CV) of both intra-assay and inter-assay were less than 1.13%.All of the samples from experimentally infected mice were positive for MPyV and 3 out of 86 clinical samples were positive by this TaqMan-PCR detection with a positive rate of 3.5%.Conclusions The real-time fluorescence quantitative TaqMan-PCR assay established in this study has high specificity, sensitivity and stability.It can be used for clinical diagnosis, routine detection and epidemiological investigation of murine polyomavirus infections.
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Objective To study the effect of the evidence-based nursing in the treatment of acute myocardial infarction by the early thrombolytic therapy with urokinase.Method 138 patients with acute myocardial infarction were randomly divided into the observation group and control group in equal number: the former received the evidence-based nursing and the latter conventional nursing care.The two groups were compared in terms of recanalization rate,fatality and incidence of angina.Result The recanalization rate,fatality and incidence of angina in the observation group were all significantly lower than those in the control group(all P<0.05).Conclusion The evidence-based nursing used to nurse the acute myocardial infarction patient to be treated by is cared by early thrombolytic therapy with urokinase may prevent such complications as angina and reduce recanalization rate and fatality.