星蒌承气汤和补阳还五汤对脑缺血大鼠细胞凋亡Fas/Fasl和Caspase-3调控的影响

目的:观察星蒌承气汤和补阳还五汤对脑缺血神经细胞凋亡Fas/Fasl和Caspase-3的影响,以明确其阻抑神经细胞凋亡的机制。方法:大鼠随机分为假手术组、模型组、尼莫地平组、星蒌承气汤和补阳还五汤组;线栓法制备大脑中动脉阻塞模型;星蒌承气汤(5.0 g·kg-1)、补阳还五汤(13.0 g·kg-1)、尼莫地平(10.8 mg·kg-1)组大鼠分别于造模前4 d灌胃,造模后每日1次;缺血后1,3,7 d取大鼠脑组织,免疫组织化学法检测Fas,Fasl,Caspase-3表达。结果:假手术组大鼠可见少许Fas(16.60±1.36),Fasl(19.40±1.72)和Caspase-3(16.35±1.63)表达;大鼠缺血后1,3,7 d的Fas(45.83±1.44,36.25±1.60,31.37±2.27),Fasl(44.27±2.25,37.68±2.01,34.15±1.55)和Caspase-3(37.18±2.78,29.50±2.07,25.26±3.04)表达均增强(P<0.01);与模型组比较,各用药组Fas,Fasl表达减弱,尼莫地平组缺血后1 d,星蒌承气汤和补阳还五汤各组Caspase-3表达减弱;各星蒌承气汤和补阳还五汤组7 d的Fas,Fasl表达、星蒌承气汤组3 d的Caspase-3表达均较尼莫地平组减弱;星蒌承气汤组缺血后1 d的Fas和Fasl,3 d的Fas和Caspase-3表达均较补阳还五汤组减弱。结论:脑缺血可引起细胞凋亡Fas/Fasl调控的表达上调,星蒌承气汤和补阳还五汤可下调Fas/Fasl及Caspase-3表达,星蒌承气汤阻抑Fas和Fasl及Caspase-3的作用较补阳还五汤早而显著,以缺血后1 d的调控作用最为明显。     

Growth inhibitory effect of wild-type Kras2 gene on a colonic adenocarcinoma cell line

AIM: To observe the growth inhibitory effect of wild-type Kras2 gene on a colonic adenocarcinoma cell line Caco-2. METHODS: Recombinant plasmid pCI-neo-Kras2 with wild type Kras2 open reading frame was constructed. The Caco-2 cells were transfected with either pCI-neo or pCI-neo-Kras2 using Lipofectamine 2000. The expression of wild type Kras 2 was examined by Northern blot analysis. And the expression of wild type Kras2 protein was examined by Western blot analysis. The effects of wild-type Kras2 on cell proliferation were analyzed by monotetrazolium (MTT) assay, meanwhile analyses of cell cycle and spontaneous apoptosis rate were carried out by flow cytometry (FCM). RESULTS: The plasmid of pCI-neo-Kras 2 was successfully established. The growth rate of cells transfected with pCI-neo-Kras2 was significantly lower than the control cells transfected with the empty pCI-neo vector (P < 0.05). Cell cycle analysis revealed arrest of the pCI-neo-Kras2 transfected cells in G0/G1 phases, decreased DNA synthesis and decreased fractions of cells in S phase. The proliferative index of cells transfected with pCI-neo-Kras2 was decreased compared with the control cells (49.78% vs 64.21%),while the apoptotic rate of Caco-2 cells with stable Kras 2 expression increased (0.30% vs 0.02%). CONCLUSION: The wild-type Kras2 gene effectively inhibits the growth of the colonic adenocarcinoma cell line Caco-2.     

组胺对大鼠正常肝细胞及缺氧/复氧时肝细胞活力的影响

目的:评价组胺对大鼠正常肝细胞及缺氧/复氧时肝细胞活力的影响。方法:大鼠肝细胞株,调整细胞密度为1×107cells/L,接种于培养孔中,每孔200μL作为研究对象,本研究包括2个实验,各实验中研究对象随机分为7组。实验1:空白组和2×104μg/L组各12孔,其它各组各6孔,空白组不做任何处理,10μg/L组、102μg/L组、103μg/L组、104μg/L组、2×104μg/L组和5×104μg/L组分别加入相应浓度的组胺,孵育25h,各组取6孔,测定肝细胞活力,取空白组和2×104μg/L组的其它6孔,收集细胞培养上清液和细胞,分别用于测定谷丙转氨酶(ALT)和超氧化物歧化酶(SOD)的活性,电镜观察细胞超微结构。实验2:分组方法同实验1,空白组和2×104μg/L组各12孔,其它各组各6孔,空白组不做任何处理,加入相应浓度的组胺后立即进行缺氧1h、复氧24h,各组取6孔,测定肝细胞活力,取空白组和2×104μg/L的其它6孔,收集细胞培养上清液和细胞,分别用于测定ALT和SOD的活性,电镜观察细胞超微结构。结果:实验1:与空白组比较,103μg/L组-5×104μg/L组肝细胞活力增加,且呈浓度依赖性,2×104μg/L组SOD活性升高(P0.05),ALT活性差异无显著(P0.05);电镜下空白组和2×104μg/L组肝细胞未见损伤。实验2:与空白组比较,102μg/L组-5×104μg/L组肝细胞活力降低,其中2×104μg/L组和5×104μg/L组肝细胞活力降低更明显,2×104μg/L组ALT活性升高,SOD活性降低(P0.05),2×104μg/L肝细胞损伤重于空白组。结论:组胺可增加大鼠正常肝细胞活力,且呈浓度依赖性,2×104μg/L组胺可提高其抗氧化能力;组胺可降低缺氧/复氧时大鼠肝细胞活力,且与浓度有关,2×104μg/L组胺可降低其抗氧化能力。     

Recombinant 56-kilodalton major outer membrane protein antigen of Orientia tsutsugamushi Shanxi and its antigenicity

The gene encoding the 56-kDa protein of Orientia tsutsugamushi Shanxi was amplified by a nested PCR and cloned into the expression vector pQE30. The 56-kDa protein of O. tsutsugamushi Shanxi (Sxh56) was expressed as a fusion protein with the His(6)-binding protein of Escherichia coli by deleting the signal peptide-encoding sequence from the 5' end of the open reading frame. The recombinant protein formed inclusion bodies when expressed in E. coli M15. The recombinant protein was examined for reactivity with mouse sera against three antigenic prototypes of O. tsutsugamushi by an immunoblot assay. The recombinant Sxh56 reacted only to polyclonal antiserum to O. tsutsugamushi Gilliam in an enzyme-linked immunosorbent assay (ELISA) and in an immunoblot assay. Recombinant Sxh56 was purified by Ni-nitrilotriacetic acid affinity chromatography and injected into mice to evaluate its ability to stimulate immune responses. High levels of immunoglobulin G and T-cell proliferation appeared in mice immunized with the recombinant protein. The recombinant Sxh56 was used in an ELISA to evaluate the ability of the method to detect antibodies to O. tsutsugamushi in human and animal sera. Thirty sera from mice infected with O. tsutsugamushi Gilliam or Shanxi and 55 sera from normal mice were detected in the ELISA with recombinant Sxh56, and the sensitivity and specificity were 96.67 and 100%, respectively. One hundred fifty-one positive sera and 412 negative sera to O. tsutsugamushi Gilliam were detected in an indirect immunofluorescence assay with the recombinant protein, and the sensitivity and specificity were 96.36 and 88.08%, respectively. These results strongly suggest that the recombinant Sxh56 is a suitable type-specific immunodiagnostic antigen and vaccine candidate.     

大鼠腮腺的5-羟色胺免疫组织化学

目的：观察大鼠腮腺内5-HT的分布。方法：免疫组织化学ABC法。结果：大鼠腮腺各级导管的上皮细胞、毛细血管及小血管的内皮细胞均呈5-HT免疫反应阳性。免疫反应物分布于胞质，胞核为阴性反应。结论：大鼠腮腺各级导管上皮细胞内含有5-HT，其存在对腮腺的功能可能有一定调节作用。     

2008年北京市HIV-1耐药株传播调查

目的 了解2008年北京市未经抗病毒治疗HIV-1感染者中耐药株传播水平,为耐药监测和临床抗病毒治疗工作提供本底资料.方法 参照WHO提出的HIV耐药警戒线调查方法(HIV drug resistance threshold survey,HIVDR-TS)指导方案,收集6个月内检测发现的60～70名小于25岁的感染者血浆样本,检测HIV-1 pol区亚型及耐药基因型,并计算耐药株检出率、评价传播水平.结果 61份符合要求的样本共获得50个有效pol区序列.感染途径以同性传播为主,占62%;亚型分布以B(42%)、CRF01_AE(28%)、CRF07_BC(26%)3种为主.出现1例针对PI类药物的耐药突变株,检出率为2%(1/50);出现1例针对NRTI类药物的耐药突变株,检出率为2%(1/50);未出现针对NNRTI类药物的耐药突变株,检出率为0.蛋白酶(PR)区和逆转录酶(RT)区的耐药突变株检出率均为2%,均属于低度传播范围(<5%).结论 北京市未经抗病毒治疗HIV-1感染者中出现PR和RT区的耐药突变株,传播水平尚处于低流行状态,现有的抗病毒治疗方案是可行的,治疗前尚不需要进行大规模耐药性检测.     

普氏立克次体120kDa表面蛋白N端和C端重组蛋白的抗原特异性研究

用免疫印迹和酶联免疫吸附试验分析普氏立克次体N端和C端重组蛋白,发现2个重组蛋白除与普氏立克次体免疫血清发生特异性反应外,并与立氏立克次体免疫血清发生反应,这2种立克次体也被这2个重组蛋白免疫血清所识别,提示这2个重组蛋白含有普氏和立氏立克次体的共同抗原决定簇。     

五日热巴通体重组外膜蛋白HbpA的研制和抗原性分析

为克隆并表达五日热巴通体外膜蛋白HbpA的基因,并对其抗原性进行初步分析,采用PCR方法从五日热巴通体基因组DNA扩增hbpA基因,将目的基因片段插入原核表达质粒pET32a（＋）,构建重组质粒pET32a（＋）-hbpA;将构建的重组质粒转化大肠杆菌BL21（DE3）并诱导目的基因表达,以SDS-PAGE电泳以及免疫印迹实验分析表达的目的蛋白。SDS-PAGE电泳分析发现pET32a（＋）-hbpA转化菌高效表达一48kDa重组蛋白;免疫印迹分析发现该蛋白与其免疫血清发生强烈反应;间接免疫荧光分析发现该重组蛋白免疫血清能特异识别五日热巴通体。实验结果表明五日热巴通体外膜蛋白HbpA的基因已在大肠杆菌中高效表达。     

2008年北京市HIV-1耐药株传播调查

目的 了解2008年北京市未经抗病毒治疗HIV-1感染者中耐药株传播水平,为耐药监测和临床抗病毒治疗工作提供本底资料.方法 参照WHO提出的HIV耐药警戒线调查方法(HIV drug resistance threshold survey,HIVDR-TS)指导方案,收集6个月内检测发现的60～70名小于25岁的感染者血浆样本,检测HIV-1 pol区亚型及耐药基因型,并计算耐药株检出率、评价传播水平.结果 61份符合要求的样本共获得50个有效pol区序列.感染途径以同性传播为主,占62%;亚型分布以B(42%)、CRF01_AE(28%)、CRF07_BC(26%)3种为主.出现1例针对PI类药物的耐药突变株,检出率为2%(1/50);出现1例针对NRTI类药物的耐药突变株,检出率为2%(1/50);未出现针对NNRTI类药物的耐药突变株,检出率为0.蛋白酶(PR)区和逆转录酶(RT)区的耐药突变株检出率均为2%,均属于低度传播范围(<5%).结论 北京市未经抗病毒治疗HIV-1感染者中出现PR和RT区的耐药突变株,传播水平尚处于低流行状态,现有的抗病毒治疗方案是可行的,治疗前尚不需要进行大规模耐药性检测.     

瘦素对缺氧复氧L02肝细胞凋亡及Fas/FasL表达的影响

目的： 观察瘦素(leptin)对缺氧复氧人正常肝细胞（L02）凋亡的影响。方法: 将L02细胞分别分为正常对照组、单纯缺氧12 h复氧组(IR组)和缺氧12 h复氧加不同浓度的瘦素（分别为100 μg/L、200 μg/L、400 μg/L、800 μg/L 和1 600 μg/L）干预组, 以流式细胞仪分析、DNA缺口末端标记 (TUNEL) 试验、荧光定量 PCR 等方法观察leptin 对L02肝细胞凋亡、Fas/FasL mRNA表达的影响。结果: （1）与正常对照组相比,IR组细胞凋亡率和TUNEL细胞阳性率增加（P<0.01）,加用不同浓度瘦素干预组的细胞凋亡率和TUNEL细胞阳性率与IR组相比明显下降（P<0.05）;（2）与正常对照组相比,IR组 L02 细胞中Fas/FasL mRNA表达明显上调(P<0.01);加用不同浓度瘦素干预组与IR组相比,Fas/FasL mRNA表达下降,以400 μg/L瘦素作用明显,结果有显著差异（P<0.05）。结论: 瘦素能减轻缺氧复氧培养L02肝细胞的凋亡,其机制可能与其下调细胞中Fas/FasL mRNA的表达有关。