Objective To compare the reversal effects of short hairpin RNA (shRNA) interference and tetrandrine on multidrug resistance (MDR) of human colorectal cancer cell line LoVo/5-fluorouracil(5-FU ).Methods An eukaryotic expression plasmid of shRNA targeting MDR1 was constructed and transfected into human colorectal cancer cell line LoVo/5-FU (transfection group).LoVo/5-FU was also pretreated with tetrandrine (tetrandrine group).Drug sensitivity was detected by methyl thiazolyltetrazolium colorimetric method.Cell cycle,apoptosis of cells and positive expression rate of P-glycoprotein (P-gp) were determined by flow cytometry assay.The expressions of MDR1 mRNA and P-gp were detected by real-time polymerase chain reaction and Western blot,respectively.All data were analyzed by analysis of variance and SNK-q test.Results (1)Drug sensitivity:the 50％ concentration of inhibition(IC50)of the control group,tetrandrine group and transfection group were (7.3 ± 0.3),(4.4 ±0.7) and (2.4 ±0.4) mmol/L,respectively,a significant difference between the 3 groups was found(F =65.27,P ＜ 0.05 ).There was a significant difference in the IC50 between the tetrandrine group and the transfection group (q =6.67,P ＜ 0.05 ).(2) Changes of cell cycle:the proportion of cells in the G1 phase and S phase of the control group,tetrandrine group and transfection group were 38.13％ ± 3.75％,51.36％ ± 2.76％,59.24％±4.31％ and 20.46％±2.23％,14.32％± 1.91％,9.40％± 1.65％,respectively,a significant difference between the 3 groups was found(F =25.23,24.37,P ＜ 0.05 ).There were significant differences in the proportion of cells in the G1 phase and S phase between the tetrandrine group and the transfection group(q =3.67,4.35,P ＜ 0.05 ).(3) Cell apoptosis:the cell apoptotic rates of the control group,tetrandrine group and transfection group were 1.32％ ± 0.47％,3.24％ ± 0.26％,5.88％ ±- 0.44％,respectively,a significant difference between the 3 groups was found(F =99.26,P ＜ 0.05 ).There was a significant difference in the cell apoptotic rate between the tetrandrine group and transfection group(q =11.48,P ＜ 0.05 ).(4)The expression of P-gp:the positive expression rates of P-gp of the control group,tetrandrine group and transfection group were 96.9％ ± 2.3％,61.6％ ± 4.9％,76.6％ ± 3.6％,respectively,a significant difference between the 3 groups was found(F =67.83,P ＜ 0.05 ).There was a significant difference in the positive expression rate of P-gp between the tetrandrine group and transfection group (q =6.97,P ＜ 0.05 ).(5)The mRNA expression of MDR1:the mRNA expressions of MDR1 of the control group,tetrandrine group and transfection group were 1462 ±161,570 ±85,233 ± 81,respectively,a significant difference between the 3 groups was found(F =90.59,P ＜ 0.05 ).There was a significant difference in the mRNA expression of MDR1 between the tetrandrine group and transfection group (q =5.12,P ＜ 0.05 ).Conclusions MDR1 shRNA and tetrandrine could reverse M DR1 gene-mediated m.ultidrug resistance in human colon cancer cell line LoVo/5-FU,but the effect of MDR1 shRNA is better than that of tetrandrine.MDR1 shRNA and tetrandrine might take effect by inhibiting P-gp expression and down-regulating mRNA expression of MDR1.

Objective:To evaluate the optimization efficacy of ropivacaine mixed with nalbuphine for epidural labor analgesia through comparison with ropivacaine mixed with sufentanil in primiparas.Methods:Four hundred and forty primiparas with a singleton fetus in vertex presentation without abnormal fetus, aged 19-36 yr, at 37-42 weeks of gestation, who were suitable and volunteered to receive epidural labor analgesia, were selected and randomly divided into observation group (NR group, n=220) and conventional group (C group, n=220).Epidural labor analgesia solution contained nalbuphine 40 mg and ropivacaine 120 mg in 150 ml of normal saline in group NR.Epidural labor analgesia solution contained sufentanil 50 μg and ropivacaine 120 mg in 150 ml of normal saline in group C. The analgesia pump was set up to deliver a 5 ml bolus dose with a 20-min lockout interval, programmed intermittent bolus 10-15 ml/h and background infusion at 2 ml/h after an initial dose of 15 ml to maintain VAS score <3.The length of labor, adverse reactions during labor analgesia, neonatal Apgar score, parameters of umbilical artery blood gas analysis and neonatal behavioral neurological assessment score were recorded. Results:Compared with group C, the incidence of urinary retention, pruritus, nausea and vomiting and fever at birth was significantly decreased in group NR ( P<0.05).The duration of the first and second stages of labor, neonatal Apgar score, pH value of umbilical artery blood, lactate concentrations, and neonatal behavioral neurological assessment score were within the normal range in both groups, and there was no significant difference between the two groups ( P>0.05). Conclusions:Compared with conventional medication, nalbuphine mixed with ropivacaine has the same efficacy when used for epidural labor analgesia in primiparas, but it has a certain optimization efficacy in terms of safety.