苦参碱注射液对小鼠急性酒精性肝损伤的保护作用

目的探讨苦参碱注射液预处理对急性酒精性肝损伤小鼠模型的保护作用。方法将30只昆明小鼠随机分为空白组、模型组、阳性对照组(联苯双酯滴丸125 mg/kg)、苦参碱注射液高剂量组(2.8 mg/kg)、苦参碱注射液低剂量组(1.4 mg/kg),每组6只。各给药组按照10 ml/(kg·d)进行尾静脉注射,连续治疗14 d。第15天除空白组外,其余各组按照12 ml/kg一次性给予50%乙醇复制急性酒精性肝损伤模型,小鼠禁食不禁水,16 h后摘眼球取血并处死。采用HE染色观察小鼠肝脏病理变化,油红O染色检测肝脂肪沉积,检测血清丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、总胆红素(T-BIL)和肝组织中丙二醛(MDA)、超氧化物歧化酶(SOD)、还原型谷胱甘肽(GSH)、过氧化氢酶(CAT)、甘油三酯(TG)水平。结果模型组肝指数较空白组增加(P<0.05),苦参碱高剂量组、苦参碱低剂量组、阳性对照组较模型组降低(P<0.05)。模型组血清AST、ALT、T-BIL较空白组升高(P<0.05),阳性对照组、苦参碱高剂量组、苦参碱低剂量组较模型组降低(P<0.05)。模型组SOD、GSH、CAT较空白组降低(P<0.05),MDA、TG较空白组升高(P<0.05)。阳性对照组、苦参碱高剂量组的GSH、CAT、SOD较模型组升高(P<0.05),MDA、TG较模型组降低(P<0.05)。模型组肝脏脂滴数量较空白组增加(P<0.05),阳性对照组、苦参碱高剂量组、苦参碱低剂量组较模型组减少(P<0.05)。结论苦参碱注射液可以调节血清转氨酶,改善肝功能,提高抗氧化酶,改善氧化应激,对急性酒精性肝损伤有预防、治疗作用。

RNA interference of pax2 inhibits growth of transplanted human endometrial cancer cells in nude mice

The development of human endometrial carcinoma(HEC) is a complex pathologic process involves several oncogenes and tumor suppressor genes.The full-length paired-box gene 2(pax2),a recently discovered oncogene,promotes cell proliferation and growth and inhibits apoptosis of HEC cells.Here,we examined the effect of pax2 small interfering RNA(siRNA) on the growth of transplanted HEC cells in nude mice.The expression of Pax2 in 21 cases of normal endometrium and 38 cases of HEC was examined by immohistochemistry(IHC).HEC models were developed by subcutaneously transferring HEC cells into nude mice,followed by treatment with empty lentivirus vector,lentivirus vector-based pax2 siRNA,and phosphate buffered saline,respectively.Four weeks later,tumor size was measured,tumor inhibition rate was calculated,and histological analyses were conducted after staining with hematoxylin and eosin.The expression of Pax2 and Bcl-2 was detected by Western blot;proliferating cell nuclear antigen(PCNA) was detected by IHC.Significant differences were observed in the positive rate of Pax2 between normal endometrium and HEC(14.2% vs.60.5%,P<0.01).The expression index of Pax2 in well differentiated tumors was 1.88±1.68,much lower than that in tumors of moderate(3.07±1.96,P<0.05) or poor differentiation(5.45±2.76,P<0.01).Tumor necrosis increased,nuclear basophilia stain decreased,tumor growth was inhibited,and PCNA,Pax2,and Bcl-2 expression was reduced in HEC models treated with pax2 siRNA.These results indicate that Pax2 expression is related to HEC tumor biology with the increased expression of Pax2 correlated to malignancy.pax2 siRNA down-regulates Pax2 expression and inhibits tumorigenesis of HEC in nude mice,possibly due to cell apoptosis and the inhibition of tumor proliferation induced by down-regulation of Bcl-2.

Hepatitis B virus X protein regulates the mEZH2 promoter via the E2F1-binding site in AML12 cells

Histone lysine methyltransferase EZH2 has been reported to be frequently overexpressed in hepatocellular carcinoma(HCC) tissues and associated with hepatocarcinogenesis.However,the exact mechanism of EZH2 up-regulation in HCC has not been determined.In this study,we used murine hepatocyte AML12 cells to investigate the role of hepatitis B virus X protein(HBx) in regulating the expression of mEZH2.Western blot analysis demonstrated that the expression level of mEZH2 protein in AML12 cells was up-regulated by HBx in a dose-dependent manner.To further investigate the mechanism of mEZH2 overexpression,the 2500 bp regulatory sequence upstream from the first exon of the mEZH2 gene was amplified from AML12 genomic DNA and constructed into a luciferase reporter plasmid.The luciferase activity of the mEZH2 promoter significantly increased in AML12 cells co-transfected with HBx plasmid,and deleting the-486/-214 promoter region decreased HBx-induced mEZH2 promoter activation by nearly 50%.The-486/-214 region was then analyzed in the TRANSFAC 6.0 database and a typical E2F1-binding site was found.Mutation of this E2F1-binding site or knockdown of E2F1 expression by RNAi led to a dramatic decrease in HBx-induced activation of the mEZH2 promoter and mEZH2 overexpression in AML12 cells.These results provide evidence that HBx up-regulates mEZH2 expression by transactivating the mEZH2 promoter through E2F1 transcription factor,thereby providing new epigenetic evidence for the carcinogenic effect of HBx.

Investigation on subsurface vortices within a closed pump intake under different pressure conditions

An experimental study to investigate various features of subsurface vortices and their evolutions inside a closed pump intake under different pressure conditions at free surface,and to analyze the influence of a pipe bell with different mean axial velocities at the same water level on flow patterns is presented.For all cases,three different flow regimes are closely observed:various side-wall attached,back-wall attached and submerged vortices structures,and their evolutions are subject to the free-surface pressure for a critical flow rate,the number and strength of all these vortex rise as the absolute value of the pressure increases for a higher flow rate,for a lower flow rate,whether the side-wall vortices occur or not is related closely to the pressure magnitude,and there are no vortices for lower absolute pressure values,the number and the strength of the side-wall vortices increase as the absolute pressure values increase.Besides,based on statistical analyses,the side-wall vortex probability on the right side along the stream-wise direction is much higher than that on the opposite side for all operation cases,particularly single vortex probability,and the back-wall vortex probabilities are quite higher with values of more than 90%,meanwhile,the multi-vortices probability is much higher than that of the single-vortex.The captured vortices have been qualitatively classified into different“vortex zones”:no vortex zones and vortex zones including transition,single-and multi-vortex.The Reynolds number and the absolute value pressure are the most important parameters which influence the existence and the number of these vortices,and the increase of the two parameters reduces the no vortex transition zone and causes bigger difference in the back-wall and side-wall vortex zones.