人类全长新cDNA ARG1的抗砷功能研究

目的 探讨人类新基因ARG1的抗砷性.方法 将ARG1阅读框克隆于真核表达载体,真核转染于人肝细胞(L-02细胞),筛选并扩增稳定表达细胞,用细胞增殖试剂盒(XTT)检测转染细胞的抗砷性.结果 低水平(3、5、8 μmol/L)亚砷酸钠(NaAsO2)时,ARG1稳定转染细胞AH组(-0.348±0.133、0.070±0.029、0.286±0.052)、AM组(-0.258±0.130、0.091±0.089、0.219±0.066)与空白对照组(0.141±0.029、0.376±0.011、0.451±0.022)和空质粒转染组(0.118±0.030、0.310±0.031、0.459±0.036)相比,细胞死亡率明显降低(P＜0.05或＜0.01);较高水平(13、20、30 μmol/L)NaAsO2时,AH组(0.624 ±0.036、0.721±0.027、0.713±0.023)、AM组(0.558 ±0.027、0.629±0.025、0.616±0.024)与空白对照组(0.621±0.016、0.673±0.011、0.666±0.002)和空质粒转染组(0.599±0.013、0.704±0.014、0.704±0.018)相比,细胞死亡率未见明显改变(P＞0.05).结论 当NaAsO2＜13 μmol/L时,细胞中过量表达的ARG1蛋白可以增加细胞抗砷性.ARG1的基因产物具有抗砷功能,是一条新的抗砷基因.     

三磷酸腺苷结合盒转运子A1在真核细胞中的表达及对细胞抗砷性的影响

目的 研究含有三磷酸腺苷结合盒转运子A1(ABCA1)基因的真核表达载体pcDNA3.1/ABCA1转染真核细胞后,在细胞中的表达及对细胞抗砷性的影响.方法 由脂质体介导将pcDNA3.1/ABCA1重组质粒转染入人HeLa细胞中(转染重组质粒组),同时设转染空质粒组及未转染组作为对照,用实时定量PCR法检测各组细胞ABCA1 mRNA表达水平,用蛋白免疫印记法(Western blot)检测ABCA1蛋白的表达.转染48 h后,以不同剂量[0(对照)、4、8、16、32、64、128 μmol/L]亚砷酸钠(NaAsO2)染毒,用四甲基偶氮噻唑蓝(MTT)法检测细胞生存率.结果 转染重组质粒组、转染空质粒组及未转染组ABCA1 mRNA表达量分别为(2.09±0.08)×10-4、(0.09±0.02)×10-4、(0.08±0.02)×10-4,组间比较差异有统计学意义(F=1499.23,P<0.01),其中转染重组质粒组ABCA1 mRNA表达量高于转染空质粒组和未转染组(P均<0.01).转染重组质粒组、转染空质粒组及未转染组在相对分子质量(Mr)为254 × 103处均有特异性蛋白条带,其大小与ABCA1蛋白大小相符,且转染重组质粒组蛋白表达量明显高于转染空质粒组及未转染组.在NaAsO2剂量为4、8、16、32、64、128μmol/L时,转染重组质粒组细胞生存率[(94.8±0.9)%、(86.5±2.6)%、(77.8±2.0)%、(56.0±2.0)%、(23.8±1.7)%、(18.6±0.6)%]均高于转染空质粒组[(85.3±1.1)%、(78.7±0.6)%、(67.8±2.4)%、(43.2±1.5)%、(14.5±1.3)%、(8.0±0.4)%],二者比较差异有统计学意义(t值分别为18.985、6.689、5.922、9.504、9.481、32.634,P均<0.01).结论 ABCA1基因经转染后在HeLa细胞中呈现高表达状态,并使HeLa细胞对砷的耐受性提高.     

抗砷基因研究进展

砷是广泛存在于自然环境中的有毒元素。在生物进化的过程中 ,许多生物从细菌到哺乳动物都产生了对抗砷毒的生理机制 ,而这些机制的产生往往由其遗传学基础所决定。随着分子生物学及分子遗传学的飞速发展 ,抗砷机制的研究也进入到了分子水平 ,一些抗砷基因相继被发现 ,其结构和功能也逐步被摸清。下面就此做一综述。1　细菌抗砷基因用砷剂治疗感染性疾病和热带疾病在西方已有一定的历史 ,在中国用砷剂治疗疾病历史则更为长久。在砷剂的使用过程中 ,经常发现对砷剂的拮抗作用 [1 ]。 196 8年 ,Novick[2 ]报道了金黄色葡萄球菌由质粒介导的砷…     

458nt～1308nt乙型肝炎病毒剪接特异性蛋白对Huh7细胞基因表达的影响

目的研究458nt~1 308nt乙型肝炎病毒剪接特异性蛋白TSR′r′对Huh7细胞基因表达的影响,探讨其可能的致病机制。方法PCR扩增TSR′r′编码序列并克隆入pcDNA3.1/HisC。以FuGENE6将重组表达载体及相应空载体分别瞬时转染Huh7细胞,Trizol抽提细胞总蛋白与总RNA;以融合表达多肽表位抗体为一抗,Western blot检测目的蛋白的表达;用Affymetrix Genechip U133 plus 2.0人类基因表达谱芯片检测Huh7肝细胞基因转录的变化,并以半定量RT-PCR进一步验证。结果成功构建重组真核表达载体pcDNA3.1/HisC-TSR′r′,转染48 h后在Huh7细胞中表达TSR′r′蛋白。TSR′r′导致Huh7细胞载脂蛋白H等27个基因转录上调,其中包括5种代谢相关基因,7种免疫相关基因,7种胶原及胞外基质基因,5种干扰素诱导蛋白基因;TSR′r′还导致Huh7细胞核受体共激活物1基因在内的7种基因转录下降。结论458nt~1 308nt乙型肝炎病毒剪接特异性蛋白可能多方面影响肝细胞功能,具有重要的致病意义。     

WWOX 基因转染对卵巢癌干细胞增殖的抑制作用及其机制探讨

目的：探讨外源性WWOX基因转染对人卵巢癌干细胞增殖的抑制作用及机制。方法用脂质体介导的方法将pcDNA3．1-WWOX真核表达载体转染人卵巢癌干细胞,分为pcDNA3．1-WWOX重组质粒组、空质粒组及未转染组。应用G418筛选阳性细胞克隆并扩增,Western blot法检测各组细胞WWOX蛋白的表达,流式细胞仪分析细胞DNA周期变化,Western blot方法检测各组细胞Cyclin D1、CDK4蛋白的表达。结果重组质粒组WWOX蛋白高表达,空质粒组及未转染组细胞未检测到WWOX蛋白的表达。重组质粒组细胞的G0/G1期细胞比例高于空质粒组及未转染组（P＜0．01）,S期比例低于空质粒组及未转染组（P＜0．01）。重组质粒组Cyclin D1、CDK4表达均低于空质粒组及未转染组（P＜0．05）。结论 WWOX基因转染可能通过下调Cyclin D1、CDK4的表达而抑制人卵巢癌干细胞增殖,可能为卵巢癌的生物治疗开辟新的思路。     

含弓形虫复合抗原基因的真核表达质粒在哺乳动物细胞中的表达

目的研究弓形虫复合抗原真核表达质粒pcDNA3.1-P30-P22-CTXA2/B在哺乳动物细胞中的表达情况。方法利用脂质体介导的转染技术,将真核表达质粒pcDNA3.1-P30-P22-CTXA2/B和空载体pcDNA3.1分别转染He-la细胞,400μg/mlG418加压筛选和200μg/mlG418维持筛选,获得稳定转染的Hela细胞。采用SDS-PAGE和West-ern-blot方法对复合基因P30-P22-CTXA2/B的表达产物进行鉴定。结果SDS-PAGE结果显示,重组质粒转染Hela细胞后的表达产物分子质量单位为64ku,Western-blot显示此蛋白条带能被抗P30抗体识别。结论构建的真核表达质粒pcDNA3.1-P30-P22-CTXA2/B能在哺乳动物细胞中成功表达插入基因所编码的融合蛋白,为进一步动物实验提供了实验依据。     

细小病毒H-1非结构蛋白NS1基因对人胃癌细胞的抑制作用研究

前期研究表明细小病毒H-1（H-1PV）对胃癌细胞生长具有一定抑制作用,非结构蛋白NSl可能是其细胞毒作用的效应蛋白。胃癌细胞CD44^＋群体中可能含有肿瘤干细胞。目的：探讨H-1PV非结构蛋白NSl基因对不同分化程度的人胃癌细胞的影响。方法：以双酶切和质粒测序鉴定真核表达质粒pcDNA3．1-NSl,采用脂质体法将重组质粒转染高分化胃癌MKN28细胞、中分化胃癌SGC7901细胞和低分化胃癌MKN45细胞,并设置空质粒转染对照。G418筛选稳定转染的细胞克隆．以RT-PCR法检测NSl基因表达、裸鼠体内成瘤实验检测NSl基因对不同分化程度胃癌细胞的作用．流式细胞术分析CD44表达。结果：重组质粒pcDNA3．1-NSl转染的三种胃癌细胞均稳定表达NSl基因。以10^6／300μl浓度的肿瘤细胞皮下接种裸鼠3周后,MKN28细胞空质粒转染组和重组质粒pcDNA3．1-NSl转染组均观察到肿瘤生长;SGC7901、MKN45细胞空质粒转染组形成瘤体,而重组质粒pcDNA3．1-NSl转染组未见瘤体。转染重组质粒pcDNA3．1-NSl后,MKN28细胞不表达CD44,SGC7901和MKN45细胞CD44表达明显降低。结论：H-1PV非结构蛋白NSl基因表达对中低分化的胃癌细胞有较好的抗肿瘤活性．可能与其降低胃癌干细胞表型CD44的表达有关。     

胃癌相关基因GCRG213正反义真核表达载体的构建及鉴定

目的:构建胃癌相关基因GCRG213正、反义真核表达载体．方法:从pGEM-T质粒上扩增出的胃癌相关基因GCRG213的DNA片段,两端分别引入限制性内切酶KpnI,BamHI和EcoRI, BamHI识别位点．按正向、反向克隆入真核表达载体pcDNA3．1( )．测序正确的重组子pcDNA3．1-a(含GCRG213正向克隆), pcDNA3．1-b(含GCRG213反向克隆)和空载体经脂质体转染人胃癌细胞系MKN45细胞, G418筛选获得稳定转染的细胞株,采用半定量RT-PCR及Wlestern blot比较转染不同质粒的 MKN45细胞中GCRG213在mRNA和蛋白质水平上的表达差异．结果:经测序证实,GCRG213正向克隆和反向克隆正确插入真核表达载体 pcDNA3．1( ),组成重组子pcDNA3．1-a(含正向克隆),pcDNA3．1-b(含反向克隆)．重组子 pcDNA3．1-a,pcDNA3．1-b和空载体经脂质体转染人胃癌细胞系MKN45细胞,G418筛选获得稳定转染的细胞株．与对应的空载体比较,RT-PCR结果显示转染pcDNA3．1-a的 MKN45细胞中其mRNA的表达上调35．4％,而转染pcDNA3．1-b的MKN45细胞中其mRNA 的表达下调32．1％;Western blot结果显示转染 pcDNA3．1-a的MKN45细胞中其蛋白的表达上调49．4％,而转染pcDNA3．1-b的MKN45细胞中其蛋白的表达下调50．3％．结论:成功构建胃癌相关基因GCRG213正、反义真核表达载体．     

MORF4基因诱导HeLa细胞衰老

目的建立MORF4基因高表达诱导HeLa细胞衰老模型,探索MORF4基因对HeLa细胞衰老的影响。方法分别将pcDNA3.1(+)/Flag-MORF4和pcDNA3.1(+)空载质粒转染人宫颈癌HeLa细胞株。SA-β-Gal染色检测细胞衰老,MTT法及流式细胞术检测细胞周期变化及细胞的增殖活力,两者共同确定MG-132处理的最适条件。Western印迹检测MORF4、PCNA基因的表达。结果质粒经酶切和测序鉴定,证明pcD-NA3.1(+)/Flag-MORF4质粒中含有目的基因序列;经浓度梯度1.25、2.5、5、10μmol/L MG-132处理转染细胞2、4、24、48 h后,SA-β-Gal染色和MTT检测结果显示10μmol/L MG-132处理24 h的转染细胞明显衰老,细胞活力降低;细胞周期被阻滞在G0/G1期,S期细胞明显减少,增殖受到抑制;Western印迹检测结果显示MORF4蛋白在细胞中的含量明显升高,而与增殖相关基因PCNA表达下调。结论构建的pcDNA3.1(+)/Flag-MORF4质粒在HeLa细胞中表达;并在MG-132作用下,使MORF4基因的表达产物积累,从而影响PCNA蛋白的表达量,抑制HeLa细胞的增殖活性,阻滞细胞周期的进行,导致细胞进入衰老状态。     

丙型肝炎病毒1b基因型核心蛋白对HepG2细胞Bax与Bcl-2基因表达的影响

目的研究丙型肝炎病毒（HCV）1b基因型核心蛋白（C）对HepG2细胞B细胞淋巴瘤-2基因（Bcl-2）与Bcl-2相关X蛋白（Bax）表达的影响,以探索1b型HCV C蛋白与HepG2细胞凋亡的关系。方法利用RT-PCR扩增出HCV-1b-C基因,经双酶切后连接pcDNA3.1（-）,成功构建真核表达载体pcDNA3.1（-）/HCV-1b-C。利用脂质体转染HepG2细胞,RT-PCR及Western Blot检测其mRNA及蛋白的表达,RT-PCR及Western Blot检测转染成功后HCV-1b-C对HepG2细胞Bax与Bcl-2表达的影响,并设转染空质粒组及未处理组作对照。结果成功构建真核表达载体pcDNA3.1（-）/HCV-1b-C;瞬时转染HepG2细胞,成功表达HCV C mRNA及蛋白;转染C基因组的Bax的mRNA及蛋白相对表达量减少,与转染空质粒组及未处理组比较差异均有统计学意义（P〈0.01）;转染C基因组的Bcl-2的mRNA及蛋白相对表达量增多,与转染空质粒组及未处理组比较差异均有统计学意义（P〈0.01）。结论 1b基因型HCV C蛋白转染HepG2细胞会导致Bax表达减少及Bcl-2表达增多,降低Bax/Bcl-2比值,可能是抑制HepG2细胞凋亡的机制之一。     

氯吡格雷抵抗

氯吡格雷是一种抗血小板药物,是新型二磷酸腺苷受体拮抗剂,已广泛应用于急性冠脉综合征和经皮冠状动脉介入治疗的抗血栓治疗。但近年来的研究发现,有些患者存在氯吡格雷抵抗现象,即应用氯吡格雷治疗的患者仍会发生心血管血栓事件。     

Prevalence and characteristics of pseudohypertension in patients with “resistant hypertension”

Pseudohypertension has been described as a cause of resistant hypertension, due to medial hypertrophy of the artery from atherosclerosis. This phenomenon results in an elevated cuff pressure compared with intra-arterial measurements and is found primarily in populations with advanced age and atherosclerotic disease. The purpose of this review was to investigate the clinical picture and medical outcomes of patients with this phenomenon. We conducted a retrospective chart review between April 2009 and October 2011 of 244 patients seen in our Hypertension clinic. Baseline characteristics and outcomes of pharmacologic and lifestyle modifications were analyzed. There were 17/244 (7%) patients found to have pseudohypertension among patients enrolled. The mean number of antihypertensive medications decreased from 3.7 to 2.7, following a mean of 4.1 visits. All patients had a brachial artery bruit and triphasic blood pressure readings via Doppler. Our findings suggest that elderly patients with concomitant history of atherosclerotic disease, renal insufficiency, and diabetes mellitus have the highest risk of developing pseudohypertension. This condition should be considered in patients with resistant hypertension. Blood pressure measurement with Doppler can be considered as a noninvasive investigation. Recognition of this entity may result in potential cost reduction with fewer medications prescribed.     

铜绿假单胞菌113株的耐药性分析

目的：分析铜绿假单胞菌对常用抗菌药物的耐药性,以指导临床对铜绿假单胞菌的合理用药。方法采用湖南天地人公司生产的TDR．200B细菌分析系统对临床标本中分离出的铜绿假单胞菌进行药敏试验,分析我院2010-02～2012-02分离的113株铜绿假单胞菌的耐药性。结果铜绿假单胞菌对19种常用抗菌药物的耐药率以亚胺培南最低（10.6％）,其次为阿米卡星（12.4％）;其中敏感株7株（6.2％）,多重耐药株25株（22.1％）,泛耐药株8株（7.1％）,其余耐药株73株（64.6％）。结论铜绿假单胞菌对19种常用抗菌药物存在不同的耐药性,应加强铜绿假单胞菌的耐药性监测,为临床合理选用抗菌药物提供依据。同时应对多重和泛耐药铜绿假单胞菌采取有效的预防措施,避免多重和泛耐药株的暴发流行。     

Organ transplantation from a donor colonized with a multidrug-resistant organism: a case report

The number of intensive care unit patients with infections caused by multidrug-resistant organisms is increasing in most developed countries. We report the case of a deceased multiorgan donor, who was an asymptomatic carrier of carbapenem-resistant Klebsiella pneumoniae (CR-KP) in the respiratory tract, a condition that was not diagnosed before organ harvesting and transplantation. The outcome of the 2 kidney recipients, the liver recipient, and 1 of the lung recipients was uneventful; in particular, no evidence of infection transmission or adverse graft outcomes was noted. The other lung recipient had a complicated postoperative course and, 4 weeks post transplantation, he developed a bacteremic pneumonia with CR-KP from which he subsequently died. These results suggest that, in well defined conditions, organs from donors who are CR-KP positive may be considered for transplantation.     

Translating basic science insight into public health action for multidrug- and extensively drug-resistant tuberculosis

Multidrug (MDR)- and extensively drug-resistant (XDR) tuberculosis (TB) impose a heavy toll of human suffering and social costs. Controlling drug-resistant TB is a complex global public health challenge. Basic science advances including elucidation of the genetic basis of resistance have enabled development of new assays that are transforming the diagnosis of MDR-TB. Molecular epidemiological approaches have provided new insights into the natural history of TB with important implications for drug resistance. In the future, progress in understanding Mycobacterium tuberculosis strain-specific human immune responses, integration of systems biology approaches with traditional epidemiology and insight into the biology of mycobacterial persistence have potential to be translated into new tools for diagnosis and treatment of MDR- and XDR-TB. We review recent basic sciences developments that have contributed or may contribute to improved public health response.     

Recent controversies about MDR and XDR‐TB: Global implementation of the WHO shorter MDR‐TB regimen and bedaquiline for all with MDR‐TB?

Tuberculosis (TB) is now the biggest infectious disease killer worldwide. Although the estimated incidence of TB has marginally declined over several years, it is out of control in some regions including in Africa. The advent of multidrug‐resistant TB (MDR‐TB) and extensively drug‐resistant TB (XDR‐TB) threatens to further destabilize control in several regions of the world. Drug‐resistant TB constitutes a significant threat because it underpins almost 25% of global TB mortality, is associated with high morbidity, is a threat to healthcare workers and is unsustainably costly to treat. The advent of highly resistant TB with emerging bacillary resistance to newer drugs has raised further concern. Encouragingly, in addition to preventative strategies, several interventions have recently been introduced to curb the drug‐resistant TB epidemic, including newer molecular diagnostic tools, new (bedaquiline and delamanid) and repurposed (linezolid and clofazimine) drugs and shorter and individualized treatment regimens. However, there are several controversies that surround the use of new drugs and regimens, including whether, how and to what extent they should be used, and who specifically should be treated so that outcomes are optimally improved without amplifying the burden of drug resistance, and other potential drawbacks, thus sustaining effectiveness of the new drugs. The equipoise surrounding these controversies is discussed and some recommendations are provided.     

经导管去肾交感神经术——当前各种技术的优劣比较

作为一种非药物治疗顽固性高血压新技术,经导管去肾交感神经术（renal denervation,RDN）初步已显示出其安全性和有效性.近年来不同治疗方式的RDN专用导管不断发展,基于此现对当前主要的几种经导管RDN技术进行综述.     

Preventing Clostridium difficile infections: an executive summary of the Association for Professionals in Infection Control and Epidemiology's elimination guide

This article is an executive summary of the Association for Professionals in Infection Control and Epidemiology's Clostridium difficile infection elimination guide. Infection preventionists are encouraged to obtain the original, full-length elimination guide for more thorough coverage of C difficile infection prevention.     

应用结核病DNA疫苗治疗小鼠耐多药结核病的研究

Objective To establish foundation for new strategy and program on immune therapy of multi-drug resistant tuberculosis (MDR-TB) by studying the therapeutic effects of Mycobacterium tuberculosis Ag85A plasmid DNA vaccine alone or combined with drugs on MDR-TB mice. Methods Sixty 6-8 weeks old female BALB/C mice were injected via tail vein with clinical isolate Mycobacterium tuberculosis HB361 which was highly resistant to rifampin (RFP) and lowly resistant to isoniazid. The mice were randomly divided into six groups, ten mice in each group. From the second day after infection,the mice respectively received pVAX1 vector (group A), RFP (group B), pyrazinamide (PZA) (group C),Ag85A plasmid DNA vaccine (group D), Ag85A plasmid DNA vaccine combined with RFP (group E),Ag85A plasmid DNA vaccine combined with PZA (group F) for sixty days. Four weeks after the end of treatment,the lung, liver and spleen of the mice were taken and their pathological changes, weight and colony count were examined. Results Four weeks after infection, the numbers of bacteria in lung and spleen of the mice reached up to 1.5×107 CFU and 1.1 × 106 CFU,respectively. The death rates of mice in group A and group B were both 10% ,and the mice in other groups were alive. Four weeks after the end of treatment,lung pathology in the treated groups showed that the lung lesions were slight and limited,normal alveolar structure were seen, and the profile of the alveoli was relatively clear. Compared with group A, group C, D, E, F reduced by 1.18,1.35,1.38,1.08 logs on the colony count of lung, and reduced by 0.91,1.00,1.26 and 1.03 logs on the colony count of spleen (P＜0.01), respectively. Conclusions Mycobacterium tuberculosis Ag85A plasmid DNA vaccine alone or combined with drugs has significant therapeutic effects on MDR-TB mice. Ag85A plasmid DNA vaccine combined with anti-tuberculosis drugs is the most promising immunization strategy for treatment of MDR-TB.