重叠PCR法构建宫颈癌相关的EGFR基因G719S和T790M融合重组载体

目的构建包含与宫颈癌相关的EGFR基因G719S和T790M位点重组p MD19-exon18-exon20载体,为制备突变型EGFR基因重组载体提供模板。方法以健康人全血基因组DNA作为模板,设计2对有重叠互补区的特异性引物,对EGFR基因的exon18和exon20两片段分别进行扩增,用重叠PCR技术将exon18和exon20片段进行连接,再将连接产物exon18-exon20片段插入p MD19-T质粒,构建成野生型p MD19-exon18-exon20载体,转入至大肠埃希菌感受态细胞DH5α中进行表达,利用菌液PCR和基因组测序进行鉴定。结果琼脂糖凝胶电泳结果显示,exon18和exon20两位点扩增片段在778 bp和596 bp处有清晰的目的条带,两片段的融合产物exon18-exon20片段可在1 374 bp处见一清晰目的条带;经菌液PCR和基因组测序结果鉴定,EGFR基因融合重组质粒均与预期结果一致。结论利用重叠PCR法将exon18和exon20片段进行融合,且成功构建了EGFR基因重组表达载体。     

采用定点突变PCR构建c-kit D816V突变的重组质粒标准品

目的构建含野生型c-kit基因第17号外显子片段以及含D816V突变型的重组质粒,用作检测c-kit基因D816V突变的阳性对照和阴性对照标准品。方法通过设计定点突变的克隆引物和野生型克隆引物,以健康人外周血基因组DNA为模板,采用PCR方法扩增获得突变和野生型c-kit基因17号外显子片段,将其插入pEGFP-C1载体质粒中获得重组质粒,并通过酶切和测序鉴定重组质粒,通过紫外分光光度计检测标本的浓度和纯度。结果从健康外周血细胞基因组DNA中成功扩增得到野生型和定点突变的c-kit DNA片段,并将其插入到质粒载体pEGFP-C1中,构建的阳性和阴性对照质粒经酶切和测序鉴定与目的片段完全一致。阴性和阳性质粒标准品的浓度分别为140.1μg/ml和189.9μg/ml,其OD260/OD280值分别为1.821和1.802。结论成功构建了含野生型和D816V突变的c-kit重组质粒,为检测c-kit基因D816V突变提供阴性和阳性对照以及质控品。     

三种常见CD36基因突变体标准质粒的构建

目的构建3种常见的CD36基因突变质粒,为建立高分辨率熔解曲线方法提供突变标准品。方法选取广州人群常见的CD36基因突变位点A1237C、C268T及329-330delAC作为研究位点,采用重叠延伸PCR方法及TA克隆技术构建含有上述突变位点的野生型和突变型质粒,并且对其进行测序验证。结果 DNA测序结果证实构建的3种重组质粒分别含有CD36基因A1237C、C268T、329-330delAC突变。结论成功构建CD36基因A1237C、C268T、329-330delAC突变体标准质粒,为后续建立高分辨率熔解曲线方法筛查CD36基因多态性奠定物质基础。     

重叠PCR法构建PTEN基因3位点的融合重组载体

目的构建包含与子宫内膜癌相关的PTEN基因3位点的重组p MD19-exon 5-exon 8载体。方法以健康人全基因组DNA为模板,设计2对有重叠区的特异性引物分别扩增PTEN基因的exon 5和exon 8片段,利用重叠PCR技术,将exon 5和exon 8片段进行连接,再将连接产物exon 5-exon 8片段插入p MD19-T质粒,构建成重组p MD19-exon 5-exon 8载体,转化入大肠埃希菌感受态细胞DH5α进行表达,利用菌液PCR和基因组测序进行鉴定。结果 exon 5-exon 8片段经凝胶电泳检测,可在1 253 bp处见一清晰的目的条带,PTEN基因融合重组质粒经菌液PCR及测序结果鉴定,均与预期结果一致。结论应用重叠PCR法将exon 5和exon 8片段进行融合,并成功构建了PTEN基因融合重组表达载体。     

基于PASS技术的EGFR基因突变比例检测方法的建立与评价

目的 近期临床研究发现EGFR-TKI并非对所有EGFR基因激活突变的NSCLC患者都有效,提示EGFR-TKI的治疗效果也可能与NSCLC患者中EGFR基因突变比例相关。本研究基于平行等位基因特异性测序(Parallel Allele-Specific Sequencing, PASS)方法,建立一个稳定可靠的EGFR突变基因比例检测平台。方法 构建野生型和突变型EGFR基因重组质粒,建立EGFR基因突变比例检测的PASS平台,从灵敏度、精密度以及准确度对PASS检测平台进行性能评价。结果 建立的PASS平台可用于EGFR基因点突变和缺失突变的检测,能够检测到的最小基因拷贝数为1,能够稳定检测到的最小基因拷贝数为10,在野生型基因中最低能检测出0.01%的突变基因。线性回归分析显示,检测到的突变型/野生型比例与预期的突变型/野生型比例呈良好的线性相关(R₂=0.9962)。结论 该方法的建立能够对EGFR基因突变比例进行灵敏、准确测定,这对其在临床中的应用奠定了良好的技术基础,对于评价EGFR基因突变比例与EGFR-TKI靶向治疗NSCLC患者疗效的关系也具有重...     

常氧条件下同时表达突变型低氧诱导因子1α目的蛋白和人源化绿色荧光蛋白报告分子腺病毒真核表达载体的构建

背景:低氧诱导因子1能够调控多种基因共同表达,在骨缺损部位可诱导生理功能完整的新血管生成.目的:构建能够同时表达突变型低氧诱导因子1α(hypoxia inducible factor 1 alpha,HIF-1α)目的蛋白和人源化绿色荧光蛋白(human renilla reniformis green fluorescent protein,hrGFP)报告分子的新型腺病毒真核细胞表达载体.方法:对目的基因供体质粒pCMV6-XL5-HIF1α携带的人低氧诱导因子1α基因进行测序和对其序列内部限制性内酶识别位点进行分析,利用PCR(poly-merase chain reaction,PCR)技术定点突变低氧诱导因子1α基因编码区的第402位、564位和803位氨基酸,酶切、测序检测突变情况,将正确突变后的低氧诱导因子1α基因(突变mutagenesis,突变后的HIF-1α基因写作HIF-1αmu)定向连入腺病毒穿梭载体pShuttle-CMV-IRES-hrGFP-1中.携带HIF-1αmu基因的重组腺病毒穿梭载体经测序鉴定、Pme I酶切线性化后转化BJ5183-AD-1电感受态细胞,利用细菌内同源重组机制将HIF-1αmu和人源化绿色荧光蛋白基因连同其顺势表达元件重组入腺病毒基因组质粒,通过Pac I酶切及测序鉴定获得重组体.结果与结论:经基因测序证实,HIF-1α基因编码区的第402位、564位和803位氨基酸均定点突变成丙氨酸.经酶切鉴定及测序证实,重组腺病毒表达载体构建成功.结果表明,成功构建了新型重组腺病毒突变型真核细胞表达载体pAd-HIF1αmu-IRES-hrGFP-1.     

Blimp1基因突变影响其编码蛋白转录抑制功能的体外研究

目的:探讨Blimp1基因突变在弥漫大B细胞淋巴瘤(diffuse large B-cell lymphoma,DLBCL)发病中的作用。方法:应用基因测序方法检测1例DLBCL患者Blimp1基因的突变情况;用PCR扩增其Blimp1全长编码基因,并通过定点突变获得野生型Blimp1的全长编码基因。分别将野生型、突变型Blimp1的全长编码基因亚克隆至含有Flag标签的Flag-CMV4真核表达载体中,将重组质粒分别命名为Flag-Blimp1-wt和Flag-Blimp1-mut;采用PCR扩增获得人CIITA启动子,并将扩增片段插入PGL3-Basic荧光报告基因载体中,所有重组质粒均通过酶切鉴定并测序验证序列正确;将Flag-Blimp1-wt/mut分别与PGL3-CIITA-promoter共转染293T细胞,用荧光素酶报告基因系统检测报告基因载体的活性及Blimp1基因对其表达的调控,采用蛋白印迹法检测融合蛋白Flag-Blimp1-wt与Flag-Blimp1-mut的蛋白表达差异。结果:成功构建野生型、突变型Flag-Blimp1融合蛋白表达载体及PGL3-CIITA-promoter报告基因载体;经荧光素酶报告基因检测系统证实,构建的报告基因载体具有启动子活性,野生型Blimp1蛋白对其表达具有抑制作用,且该抑制作用与Blimp1的转染剂量呈正相关,而突变型Blimp1对其抑制功能明显减弱;蛋白印迹检测结果显示,突变型Blimp1蛋白明显低于野生型。结论:该例患者中Blimp1的突变影响了其转录抑制功能,可能是由基因突变导致Blimp1蛋白表达量的减少所引起。     

荧光定量RT-PCR检测AFP mRNA基因表达方法的建立

目的　建立荧光定量RT PCR检测检测AFPmRNA基因表达的方法。方法　提取肝癌细胞株HepG2 的总RNA ,进行RT PCR扩增AFPmRNA特异性片段 ,纯化PCR产物并与pMD 18 T载体连接 ,构建重组质粒。结果　重组的质粒经酶切和测序鉴定 ,目的片段已插入 pMD 18 T载体内。 结论　成功建立荧光定量RT PCR检测AFPmRNA基因表达的方法。     

晚期肺腺癌患者奥希替尼后线治疗耐药后基因突变模式研究

目的分析外周血表皮生长因子受体(epidermal growth factor receptor,EGFR)基因T790M突变的晚期肺腺癌患者后线应用奥希替尼治疗耐药后的基因突变情况,探讨可能的耐药机制。方法晚期肺腺癌患者52例,均给予奥希替尼后线治疗,并于入院次日清晨采集外周血,提取循环肿瘤DNA,采用微滴数字PCR法检测EGFR基因T790M突变情况。对外周血检出EGFR基因T790M突变者,至病情进展时再次采集外周血,采用高通量测序进行实体瘤常见突变基因检测。结果 52例患者中36例检出外周血EGFR基因T790M突变。36例患者奥希替尼耐药后再次检测,发现10例T790M突变丢失;26例T790M突变保留,其中24例新发C797S突变;4例检出EGFR基因L718Q、L718V和L792F突变;29例检出旁路基因突变,其中MET基因突变21例(8例MET基因扩增,12例单核苷酸位点变异,1例多MET基因位点突变),12例ERBB2基因突变,7例BRAF基因突变,3例KRAS/NRAS基因突变,5例PIK3CA基因突变,1例PTEN基因突变,1例NF1基因突变,17例检出2种及以...     

一种KRAS基因突变检测方法的建立及初步应用

目的建立一种KRAS基因实时荧光定量PCR-Sanger测序突变检测方法,并初步探讨其临床应用价值。方法以KRAS基因热点突变区域12、13密码子为研究位点设计特异性扩增、测序引物,利用已知野生型、突变型样品以TA克隆技术构建相应质粒作为标准品,建立KRAS基因实时荧光定量PCR—Sanger测序突变检测方法,并进行方法学和应用评估。结果成功构建了KRAS基因12、13密码子野生型、突变型质粒。建立了KRAS基因实时荧光定量PCR—Sanger测序突变检测方法,该方法灵敏度高（9．39×10^1copies／uL）,重复性好（实时荧光定量PCR部分批内、批间变异系数分别为1．60％、2．54％）。该法与传统Sanger测序法同时检测40例临床样品,结果符合率为100％。结论本研究成功建立了可用于临床样品检测的KRAS基因实时荧光定量PCR—Sanger测序突变检测方法。     

Migraine and genetic and acquired vasculopathies

It is remarkable that migraine is a prominent part of the phenotype of several genetic vasculopathies, including cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL), retinal vasculopathy with cerebral leukodystrophy (RVCL) and hereditary infantile hemiparessis, retinal arteriolar tortuosity and leukoencephalopahty (HIHRATL). The mechanisms by which these genetic vasculopathies give rise to migraine are still unclear. Common genetic susceptibility, increased susceptibility to cortical spreading depression (CSD) and vascular endothelial dysfunction are among the possible explanations. The relation between migraine and acquired vasculopathies such as ischaemic stroke and coronary heart disease has long been established, further supporting a role of the (cerebral) blood vessels in migraine. This review focuses on genetic and acquired vasculopathies associated with migraine. We speculate how genetic and acquired vascular mechanisms might be involved in migraine.     

Fibrinogen and fibrin structure and functions

Fibrinogen molecules are comprised of two sets of disulfide-bridged Aalpha-, Bbeta-, and gamma-chains. Each molecule contains two outer D domains connected to a central E domain by a coiled-coil segment. Fibrin is formed after thrombin cleavage of fibrinopeptide A (FPA) from fibrinogen Aalpha-chains, thus initiating fibrin polymerization. Double-stranded fibrils form through end-to-middle domain (D:E) associations, and concomitant lateral fibril associations and branching create a clot network. Fibrin assembly facilitates intermolecular antiparallel C-terminal alignment of gamma-chain pairs, which are then covalently 'cross-linked' by factor XIII ('plasma protransglutaminase') or XIIIa to form 'gamma-dimers'. In addition to its primary role of providing scaffolding for the intravascular thrombus and also accounting for important clot viscoelastic properties, fibrin(ogen) participates in other biologic functions involving unique binding sites, some of which become exposed as a consequence of fibrin formation. This review provides details about fibrinogen and fibrin structure, and correlates this information with biological functions that include: (i) suppression of plasma factor XIII-mediated cross-linking activity in blood by binding the factor XIII A2B2 complex. (ii) Non-substrate thrombin binding to fibrin, termed antithrombin I (AT-I), which down-regulates thrombin generation in clotting blood. (iii) Tissue-type plasminogen activator (tPA)-stimulated plasminogen activation by fibrin that results from formation of a ternary tPA-plasminogen-fibrin complex. Binding of inhibitors such as alpha2-antiplasmin, plasminogen activator inhibitor-2, lipoprotein(a), or histidine-rich glycoprotein, impairs plasminogen activation. (iv) Enhanced interactions with the extracellular matrix by binding of fibronectin to fibrin(ogen). (v) Molecular and cellular interactions of fibrin beta15-42. This sequence binds to heparin and mediates platelet and endothelial cell spreading, fibroblast proliferation, and capillary tube formation. Interactions between beta15-42 and vascular endothelial (VE)-cadherin, an endothelial cell receptor, also promote capillary tube formation and angiogenesis. These activities are enhanced by binding of growth factors like fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor (VEGF), and cytokines like interleukin (IL)-1. (vi) Fibrinogen binding to the platelet alpha(IIb)beta3 receptor, which is important for incorporating platelets into a developing thrombus. (vii) Leukocyte binding to fibrin(ogen) via integrin alpha(M)beta2 (Mac-1), which is a high affinity receptor on stimulated monocytes and neutrophils.     

Telemedicine and teleradiology technologies and applications

Summary. Telemedicine and teleradiology hold the key for improving future health care delivery. In this paper we first review current communication and computer technologies used in telemedicine and teleradiology. Five examples in teleradiology applications are given including hospital-integrated picture archiving and communication systems, tele-neuro-imaging, telemammography, university consortium teleradiology service, and teleradiology for second opinion. Parameters important to teleradiology applications like costs, image quality, system reliability, and turn around time are considered. Data security is discussed, including patient confidentiality and image authenticity-which will be a major issue in future teleradiology applications.     

创伤高血糖与感染和MODS早期诊断和干预

本文详细介绍了创伤后血糖应激适度理论,以及高血糖与感染和多器官功能不全综合征的关系;提出涉及胰岛B细胞功能不全的MODS实验诊断新方案和极化液个体化干预新措施,可早期发现创伤MODS、降低感染率及MODS发生率和病死率。     

腹膜后纤维化与肾积水发生关系的临床研究

目的：探讨腹膜后纤维化（RPF）导致肾积水的原因及诊治经验。方法：回顾分析2004年1月—2010年12月24例腹膜后纤维化致肾积水患者的诊治资料。结果：（1）RPF患者常见首发症状为腰背痛或腹痛（69.2%）;（2）红细胞沉降率（ESR）增快和血清IgG4升高最常见。超声检查仅提示上尿路积水。RPF的静脉肾盂造影（IVP）和CT尿路成像（CTU）表现具有特征性。IVP肾盂输尿管显影不良时,CTU能较清晰的显示上尿路影像。CT扫描发现腹膜后软组织肿块9例（37.5%）,优于超声检查;（3）输尿管松解和腹腔化手术治疗22例;行肾切除术1例;行输尿管置双J管术1例。最终确诊为继发性RPF8例,其中4例为术前诊断,3例为术中腹膜后软组织肿块冷冻活检证实,1例为术后病理证实;（4）特发性RPF手术后肾积水均获长期缓解,而继发性RPF的预后取决于原发疾病及其治疗方案。结论：影像学检查是诊断RPF的重要手段,CTU优于超声检查和IVP。输尿管松解和腹腔化手术可以使特发性RPF输尿管梗阻得到长期的缓解,术中对肿块进行冷冻活检有助于鉴别特发性和继发性RPF,及时调整治疗方案。     

探讨儿童慢性顽固性咳嗽与支原体感染的关系及临床治疗观察

目的探讨儿童慢性顽固性咳嗽与肺炎支原体（MP）感染的关系及临床疗效观察。方法采用回顾性研究方法对于现将2005年3月至2008年3月在我院的55例确诊慢性顽固性咳嗽患儿,主要表现为肺炎支原体感染为临床特点进行分析,并进一步临床治疗研究。结果①临床特点：在55例确诊慢性咳嗽的患儿中,以慢性顽固性咳嗽为主要症状。58％（32／55）的病例无肺部体征;②外周血：85％（47／55）的病例外周血变化不大,WBC（4—10）×10 9／L之间,嗜酸性粒细胞增多;③特别检查：47．27％（26／55）肺炎支原体IgM（MP—IgM）抗体阳性,83．64％（46／55）PeR技术检测肺炎支原体特异性DNA;④X光报告为多种形式。结论肺炎支原体（MP）感染是引起儿童慢性顽固性咳嗽的病因之一,对儿童慢性咳嗽,特别是顽固性咳嗽的诊治中应更加重视。     

Acetaminophen and acetylcysteine dose and duration: Past,present and future

Abstract

Acetylcysteine has been utilized successfully in the treatment of acetaminophen overdose since the 1970s. Although prospective trials as to efficacy and safety of acetylcysteine were conducted, there were no randomized controlled trials. This commentary addresses the reasons for this, and the background to choice of dose of acetylcysteine utilized in the oral and IV dosing regimens. Nomograms to predict possible hepatotoxicity based upon time of ingestion of acetaminophen were developed from a relatively arbitrary definition of toxicity as an aspartate aminotransferase/alanine aminotransferase (ALT/AST) greater than 1000 IU/L. While these have proved generally useful, patients still continue to develop hepatic damage after acetaminophen overdose, particularly if they present late after ingestion. The optimum management of these patients remains unclear, and one area of uncertainty is the dose and duration of acetylcysteine in various circumstances. This article discusses the issues that need to be elucidated to better target changes in acetylcysteine dose. The potential for measurements of other markers to improve treatment selection is the subject of further research.     

VEGF和NSE在良恶性嗜铬细胞瘤中的表达及意义

目的探讨肿瘤标志物血管内皮生长因子（VEGF）和神经元特异性烯醇化酶（NSE）在良、恶性嗜铬细胞瘤组织中的表达,分析其可能的临床价值及病理学意义,为临床鉴别良、恶性嗜铬细胞瘤提供辅助依据。方法应用免疫组化（SP法）检测16例恶性嗜铬细胞瘤、18例良性嗜铬细胞瘤及17例正常肾上腺髓质组织中细胞因子VEGF和NSE表达情况,显微镜下判断组织切片的染色结果。结果①恶性嗜铬细胞瘤VEGF表达明显强于正常肾上腺髓质和良性嗜铬细胞瘤（P〈0.01）。良性肿瘤和正常肾上腺髓质的VEGF表达差异无统计学意义（P〉0.05）。恶性嗜铬细胞瘤强阳性率明显高于良性嗜铬细胞瘤（P〈0.01）。②良、恶性嗜铬细胞瘤NSE表达差异有统计学意义（P〈0.05）,良性嗜铬细胞瘤NSE的表达高于正常肾上腺髓质的NSE表达（P〈0.05）。恶性嗜铬细胞瘤强阳性率高于良性嗜铬细胞瘤（P〈0.05）。③VEGF和NSE共同阳性表达在良、恶性嗜铬细胞瘤之间差异有统计学意义（P=〈0.01）。结论临床上检测VEGF和NSE可能为鉴别良、恶性嗜铬细胞瘤提供辅助依据,共同检测VEGF和NSE可能提高良、恶性嗜铬细胞瘤鉴别的敏感性。