荧光定量聚合酶链反应检测乙型肝炎患者血清HBV DNA及临床价值

目的探讨荧光定量聚合酶链反应法定量检测乙型肝炎病毒(HBV)核酸的临床应用价值。方法应用荧光定量聚合酶链反应定量检测1962例乙型肝炎患者血清HBV DNA水平并与血清HBV标志物进行比较,并对35例乙型肝炎患者在拉米夫定治疗前后血清HBV DNA含量及相关指标作动态观察。结果乙型肝炎患者HBVDNA定量范围在6.79×102～1.95×109拷贝/毫升之间,在HBeAg阳性患者,其检出率和定量拷贝数较高。拉米夫定治疗后患者外周血HBV DNA载量下降明显。结论荧光定量PCR法是一种相对准确、灵敏度高、特异性强的定量检测HBV DNA的技术,对乙型肝炎诊断、指导、临床用药和疗效监测方面具有实用价值。     

乙型肝炎病毒共价闭合环状DNA套式-实时荧光定量聚合酶链反应的建立

目的 建立检测HBV共价闭合环状DNA(cccDNA)的套式一实时荧光定量PCR法.方法 根据HBV cccDNA与松环DNA(rcDNA)结构上的差异,设计2对跨缺口的特异引物及1条位于负链缺口下游的特异TaqMan荧光探针.根据Plasmid-SafeTM ATP-Dependent Dnasc(PSAD)对rcDNA与cccDNA作用的不同,对模板DNA进行酶切纯化,降解reDNA,再进行套式PCR扩增,先用外引物和模板进行第一轮常规PCR,再用内引物、荧光探针和第一轮PCR产物进行实时荧光定量PCR,根据阳性参照标准品,得出待检标本定量值.结果 检测阳性参照标准品.得出该方法灵敏度可达2 lg拷贝/mL.用上述方法检测34份乙型肝炎患者血清HBV DNA阳性标本,25份血清HBVcccDNA阳性,28份外周血单个核细胞HBV cccDNA阳性.27份健康对照者血清HBV DNA阴性标本,6份HBV cccDNA阳性.对5份HBV cccDNA阳性标本扩增产物进行克隆测序,无碱基缺失、突变.与HBV不同基因型序列(A～G)比较,同源性为90.6%～99.1%,其中,与B、C基因型同源性为95.3%～99.1%,验证了方法的特异度.结论 套式-实时定量PCR法可检测乙型肝炎患者血清、PBMC中的HBV CCCDNA,且具有敏感、特异性.     

DNA聚合酶链反应血清直接法测定HBV DNA

应用pADR1－HBc区的一对DNA引物，A和B（A：459－482，B：1039＝1061），首次建立了微量血清DNA聚合酶链反应（polymerase chain,reaction PCR）直接法，用常规琼脂糖凝胶电泳HBV一DNA。经双盲法测定182份血清HVB DNA，同时以HBVDNA标准样品（PBR322－HBV DNA）为模板，模拟血清直接法进行PCR测定。结果表明，该方法灵敏可靠，受检血清中仅含10fgHBVDNA时即可检出，较正向和逆向HBVDNA斑点杂交试验检测的灵敏度至少高100倍。本方法毋须从血清中提DNA，反应后仅需作常规的DNA琼脂糖电泳，观察619bpHBVDNA特异区带，以判定其结果。从而简化了方法，提高了检测的灵敏度，为推广临床应用，奠定了基础。     

贝类奥尔森派琴虫实时荧光定量PCR检测方法的建立及初步应用

目的建立一种快速、灵敏、特异的用于检测贝类奥尔森派琴虫的实时荧光定量PCR方法。方法根据基因库中奥尔森派琴虫的基因保守序列,设计合成1对引物和1条TaqMan探针,建立荧光定量PCR方法,对采自广西沿海的49份贻贝标本进行检测,并与常规PCR比较。结果建立的荧光定量PCR方法灵敏度可达20个拷贝,比常规PCR灵敏度高100倍。49份贻贝标本的阳性率为16.3%,检测的奥尔森派琴虫基因组DNA含量为2.38×10^6～9.21×10^2拷贝/μl。结论建立的荧光定量PCR方法可以用于贝类奥尔森派琴虫感染的快速检测。     

54例慢性乙型肝炎患者肝组织乙型肝炎病毒共价闭合环状DNA与血清HBsAg定量检测结果分析

目的 检测慢性乙型肝炎患者肝组织HBV共价闭合环状DNA (cccDNA)和血清HBsAg,分析两种定量指标之间及其与血清HBV DNA载量的相关性.方法 应用PSAD消化+滚环扩增+跨缺口实时荧光PCR方法,定量检测54例慢性乙型肝炎患者甲醛固定石蜡包埋肝组织HBV cccDNA水平;用化学发光试剂定量检测患者血清HBsAg.用Pearson检验及直线回归分析方法 对数据进行分析.结果 患者肝组织HBV cccDNA与血清HBsAg定量水平之间呈正相关(r=0.459,P＜0.01),但与血清HBV DNA载量相关性无统计学意义;血清HBsAg定量水平与血清HBV DNA载量呈正相关(r=0.328,P＜ 0.05),与病毒复制效率呈负相关(r=-0.373,P＜0.05).结论 慢性乙型肝炎患者肝组织HBV cccDNA载量与血清HBsAg定量水平相关,结合血清HBVDNA定量检测,可以更全面的反映HBV的复制水平,评价抗病毒疗效.     

采用高敏检测技术检测血清HBV DNA载量筛选低病毒血症的无偿献血人群隐匿性乙型肝炎病毒感染研究

目的 探讨采用高敏检测技术检测血清乙型肝炎病毒(HBV)DNA筛选低病毒血症(LLV)的无偿献血人群隐匿性乙型肝炎病毒感染(OBI)的价值。方法 2017年2月～2021年12月我市收集的11352份血清HBsAg阴性的无偿献血人群血液标本,采用电化学发光法定性检测血清HBeAg、HBeAb和HBcAb),定量检测血清HBsAb,使用AU5800型全自动生化分析仪检测血生化指标,使用ABI ViiA7型荧光定量PCR扩增仪,采用高敏PCR法检测血清HBV DNA载量,对所有经高敏PCR法检测为HBV DNA阳性的血清再使用Cobas AmpliPrep/Cobas TaqMan全自动核酸定量检测系统复核。结果 以全自动核酸定量检测系统检测结果为金标准,发现高敏PCR检测为HCV DNA阳性的67例(0.59%)为LLV人群,结果显示,该方法诊断OBI人群LLV的灵敏度和特异度均为100.0%和100.0%;金标准方法与高敏PCR检测血清HCV DNA载量差异无统计学意义【(110.7±20.2)IU/ml对(108.2±19.6)IU/ml,P>0.05】;经高敏PCR法检验发现...     

定量PCR对乙型肝炎患者血清HBVDNA的测定与分析

目的:观察各类型乙型肝炎患者血清HBV DNA复制水平及其与临床病情、乙肝血清学诊断标志变化的关系。方法:应用美国Brotronics公司的一种新型定量PCR HBV DNA检测法测定85例乙肝患者血清HBV DNA。利用荧光素标记引物在扩增过程中能量转换的原理对模板DNA进行定量检测,由计算机自动控制和分析。结果:85例乙型肝炎患者HBV DNA检出率94.1％。63例CHB与LC患者中,HBeAg阳性与抗HBe阳性病例均表现较高的HBV DNA复制水平。7例AH与3例SH乙肝血清学诊断标志不典型,但也表现一定HBV DNA水平。血清ALT的异常变化与HBV DNA复制水平无显著相关性。结论:定量HBV DNA PCR法具有很高灵敏度和特异性,定量PCR测定HBV DNA优于斑点杂交法。     

动态评价联合检测乙肝病毒前S1抗原与核心抗原的临床意义

目的：探讨联合检测乙肝病毒前S1抗原和核心抗原与HBVDNA的关系以及在乙肝诊疗中的意义。方法：对100例慢性乙肝患者的346份系列血清和486例正常对照血清采用实时荧光定量PCR（FQ-PCR）进行DNA定量检测,酶联免疫吸附试验（ELISA）进行乙肝病毒前S1抗原和核心抗原的联合检测（检测结果以HBV NRAg表示）及对乙肝血清标志物进行定性检测。结果：342份HBV DNA（＋）的血清中,有338份HBV NRAg检测为阳性,灵敏度为98．8％（95％CI：0．970-0．995）,HBV NRAg特异度为99．6％（95％CI：0．985-0．999）。45例患者的系列血清HBV NRAg的OD均值随着HBVDNA拷贝数降低而下降,且具有一定的相关性（r=0．721）。其中有两位患者的血清标本出现了HBV DNA阴转。此外在46例不明原因肝功能不良患者中,发现3例HBsAg（-）,HBV DNA（＋）的慢性乙肝患者。结论：联合检测乙肝病毒前S1和HBcAg不仅能反映乙肝患者体内HBV复制情况,而且对抗病毒药物在临床的使用具有一定的指导作用。     

荧光定量PCR检测嗜吞噬细胞无形体

目的采用新型TaqMan-MGB探针建立检测嗜吞噬细胞无形体的实时荧光定量PCR(quantitativereal-timePCR)方法。方法依据gltA基因序列设计嗜吞噬细胞无形体特异引物和探针,以克隆的嗜吞噬细胞无形体gltA基因片段作DNA模板,在荧光定量PCR检测仪(ABI7900HT)上建立实时荧光定量检测方法。结果建立的定量标准曲线的循环阈值(Ct)与模板拷贝数呈良好的线性关系(r=0.996);与套式PCR相比较,荧光定量PCR检测的灵敏度是其100倍。用荧光定量PCR检测其它相关立克次体和细菌DNA样本,检出结果几乎为0;对荧光定量PCR检测重复性进行分析,变异系数(CV)批内和批间误差在0~2.1%之间,证明该荧光定量PCR具有种特异性和良好的重复性。用荧光定量PCR检测体疑染嗜吞噬细胞无形体的10份蜱和30份小鼠脾脏标本,结果与套式PCR检测结果有密切相关性,但是定量PCR检测敏感性和准确率均高于套式PCR。结论本研究建立的检测嗜吞噬细胞无形体的实时荧光定量PCR具有很高的特异性和敏感性,特别适合检出样本中微量嗜吞噬细胞无形体。     

应用竞争性荧光定量聚合酶链反应检测乙型肝炎病毒DNA

目的:建立竞争性荧光定量聚合酶链反应(CFQ-PCR),并探讨CFQ-PCR在乙型肝炎病毒(HBV)临床检测中的意义.方法:根据HBV病毒adr亚型基因组序列合成一对HBV特异的引物,和一条特异的TaqMan探针;根据上述引物序列,采用分子克隆技术制备内对照DNA;再根据内对照序列合成一条内对照DNA特异的与上述TaqMan探针不同标记的TaqMan探针;将适量的内对照DNA加入到PCR反应体系中,使其与HBV靶序列共扩增.结果:在30μL CFQ-PCR反应体系中,加入约20拷贝内对照DNA能够稳定地获得共扩增曲线;经琼脂糖凝胶电泳分析,加入约100-500拷贝内对照DNA能够有效地获得共扩增产物条带信号;在210个临床HBsAg阳性血清标本的CFQ-PCR扩增中识别出8个未能有效扩增的标本,60份HBsAg阴性血清标本中识别出2个内对照未能有效扩增的标本,后经DNA纯化处理,上述全部标本的内对照均获得阳性扩增结果,其中有7个HBsAg阳性血清标本获得HBV DNA扩增阳性结果.结论:CFQ-PCR能够有效地提示临床标本HBV DNA体外扩增时由于扩增失败导致的假阴性,适合临床推广应用.     

Establishment and assessment of two methods for quantitative detection of serum duck hepatitis B virus DNA

AIM: To establish and assess the methods for quantitative detection of serum duck hepatitis B virus (DHBV) DNA by quantitative membrane hybridization using DHBV DNA probe labeled directly with alkaline phosphatase and fluorescence quantitative PCR (qPCR). METHODS: Probes of DHBV DNA labeled directly with alkaline phosphatase and chemiluminescent substrate CDP-star were used in this assay. DHBV DNA was detected by autoradiography, and then scanned by DNA dot-blot. In addition, three primers derived from DHBV DNA S gene were designed. Semi-nested primer was labeled by AmpliSensor. Standard curve of the positive standards of DHBV DNA was established after asymmetric preamplification, semi-nested amplification and on-line detection. Results from 100 samples detected separately by alkaline phosphatase direct-labeled DHBV DNA probe with dot-blot hybridization and digoxigenin-labeled DHBV DNA probe hybridization. Seventy samples of duck serum were tested by fluorescent qPCR and digoxigenin-labeled DHBV DNA probe in dot-blot hybridization assay and the correlation of results was analysed. RESULTS: Sensitivity of alkaline phosphatase direct-labeled DHBV DNA probe was 10 pg. The coincidence was 100% compared with digoxigenin-labeled DHBV DNA probe assay. After 30 cycles, amplification products showed two bands of about 180 bp and 70 bp by 20 g/L agarose gel electrophoresis. Concentration of amplification products was in direct proportion to the initial concentration of positive standards. The detection index was in direct proportion to the quantity of amplification products accumulated in the current cycle. The initial concentration of positive standards was in inverse proportion to the number of cycles needed for enough quantities of amplification products. Correlation coefficient of the results was (0.97, P<0.01) between fluorescent qPCR and dot-blot hybridization. CONCLUSION: Alkaline phosphatase direct-labeled DHBV DNA probe in dot-blot hybridization and fluorescent qPCR can be used as valuable means to quantify DHBV DNA in serum.     

Presence and integration of HBV DNA in mouse oocytes

AIM: Hepatitis B is a worldwide public health problem. To explore the feasibility of hepatitis B virus (HBV) vertical transmission via oocytes, the presence and integration of HBV DNA in mouse oocytes were studied. METHODS: Genomic DNA was isolated and metaphases were prepared, respectively from mouse oocytes cocultured with pBR322-HBV DNA plasmids. PCR, Southern blot, dot hybridization and fluorescence in situ hybridization (FISH) were performed to explore the existence and integration of HBV DNA in oocytes. RESULTS: PCR detected positive bands in the tested samples, and then Southern blot revealed clear hybridization signals in PCR products. Final washing solutions were collected for dot hybridization and no signal for HBV DNA was observed, which excluded the possibility that contamination of washing solutions gave rise to positive results of PCR and Southern blot. FISH demonstrated that 36 of 1 000 metaphases presented positive signals. CONCLUSION: HBV DNA sequences are able to pass through the zona and oolemma to enter into oocytes and to integrate into their chromosomes. HBV DNA sequences might be brought into embryo via oocytes as vectors when they are fertilized with normal spermatozoa.     

Detection of HBV DNA in HBsAg-positive sera after amplification using the polymerase chain reaction

The presence of hepatitis B virus (HBV) DNA in serum as detected by molecular hybridization is considered the most reliable marker for the presence of complete virions and, therefore, infectivity. This technique, however, has a lower limit of detection of 0.1 pg HBV DNA. Using the polymerase chain reaction (PCR), a technique by which DNA sequences can be amplified selectively, we investigated sera from 30 HBsAg carriers, 6 also positive for HBeAg and 24 negative for HBeAg. After PCR followed by Southern blot, 27 sera were found to be positive for HBV DNA, whereas only 7 sera were positive for HBV DNA in the conventional dot blot. PCR followed by Southern blot analysis lowered the limit of detection to 0.5 fg HBV DNA. Amplified HBV DNA fragments from some samples were directly sequenced without previous cloning. We conclude that PCR is a suitable method to amplify parts of viral genomes present in human sera, and that PCR with subsequent Southern blot analysis allows the detection of hepatitis B virions in the majority of HBsAg-positive sera.     

应用Digoxigenin标记探针定量检测血清HBV DNA

本文报道采用非同位素Ｄｉｇｏｘｉｇｅｎｉｎ标记探针定量检测血清ＨＢＶ ＤＮＡ。显色膜经空气干燥，液体石蜡透明处理后，即可置酶联免疫检测仪上测定各斑点的光密度值，液长６３０ｎｍ。结果发现已各含量的ＨＢＶ ＤＮＡ在２－５００ｐｇ／样点范围内与其相应的ＯＤ值有着良好的线性关系。标本测得ＯＤ值后，便可知其含量，该法重复性试验试验结果良好，１１份ＨＢＶ ＤＮＡ阳性的血清经定量测定，其ＨＢＶ ＤＮＡ含量在２０     

体内与转染细胞中乙型肝炎病毒株复制特性的相关性

目的 比较不同乙型肝炎病毒（HBV）株在体内及转染细胞中复制特性是否相符。方法 以核酸杂交定量和聚合酶链反应-酶联免疫吸附试验（PCR-ELISA）测定5例孕妇血清中HBVDNA含量,并测定乙型肝炎表面抗原（HBsAg)和乙型肝炎e抗原（HBeAg)含量,分别克隆血清中的HBV基因组转染细胞,检测培养上清液中HBsAg和HBeAg表达水平,并以Southern印迹及核酸杂交检测转染细胞内、外HBVDNA复制水平。结果 转染细胞内、外HBVDNA复制水平与相应血清HBVDNA量呈正相关趋势,转染细胞表达的病毒抗原水平与相应血清中病毒抗原含量也呈正相关趋势。结论 感染者血清中HBVDNA和病毒抗原的含量与毒株在细胞中复制和抗原表达水平有相符趋势。HBV不同毒株在转染细胞中的复制可基本反映体内毒株的复制特性。     

Detection of hepatitis B virus in plasma using flow cytometric analyses of polymerase chain reaction-amplified DNA incorporating digoxigenin-11- dUTP

Blood donations are routinely screened by multiple serologic assays for antigens/antibodies associated with infection by blood-borne viruses, including hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency viruses (HIV-1 and HIV-2), and human T-cell lymphotropic virus (HTLV-I and HTLV-II). A direct detection of these viruses would be more effective for the prevention of transfusion- transmitted infections than the indirect measurement of the variable host immune response to these agents. Because the polymerase chain reaction (PCR) for viral gene amplification offers the most sensitive and direct means of detecting viruses in blood, we have developed a nonisotopic PCR procedure for the detection of HBV, chosen as a prototype. The problems, common to previously described PCR methods, of nucleic acid extraction and inhibition of the PCR by plasma proteins were overcome by isolation of HBV from plasma by means of 450-microns polystyrene beads covalently coated with monoclonal antibody to the Pre- S1 region of the viral envelope protein. Detergent lysis and proteinase K digestion of the immunocaptured virions isolated from plasma released the HBV DNA. A modified PCR-amplification protocol, incorporating digoxigenin-labeled dUTP in the amplified gene products followed by hybridization with a specific biotinylated oligonucleotide probe bound to streptavidin-coated 2.8-microns magnetic beads, allowed flow cytometric analyses of HBV-specific PCR products by means of antibodies to digoxigenin labeled with fluorescein isothiocyanate. The endpoint serial dilutions of pedigreed human plasma samples containing chimpanzee infectious dose (CID50) of 10(7) for adw and CID50 of 10(7.5) for the ayw subtypes were compared in repeated testing of PCR products by our immunoreactive bead (PCR-IRB) assay. HBV DNA was consistently detected in a 5 x 10(-10) dilution of each sample. In testing 20 coded specimens of blood donors, with or without serologic markers of HBV infection, the PCR-IRB was specific and more sensitive than the PCR analyses by slot blot hybridization with radioactive probe. The PCR-IRB assay can be adapted for simultaneous detection of multiple blood-borne viruses by an automated flow cytometric analysis system.     

Evaluation of synthetic DNA probes for confirmation of Clostridium perfringens enterotoxin gene PCR products

A new diagnostic reagent was developed that is capable of detecting the presence of Clostridium perfringens rapidly and accurately compared to the conventional methods. C. perfringens enterotoxin (cpe) gene is the gene of interest since it encodes the enterotoxin responsible for food poisoning. Two new cpe-specific labeled DNA probes were evaluated using Southern and dot blot hybridization. Bacterial DNA was amplified by a duplex PCR procedure. The results showed that 40 enterotoxin producing C. perfringens strains generated two bands of amplicons with sizes of 420 and 280 bp, whereas 40 non-enterotoxin producing strains produced a single band of 280 bp on agarose gel-electrophoresis. No bands were observed from 32 strains of Clostridium spp and other bacteria. Southern blot analysis using either cpe-specific DNA or oligonucleotide probe showed hybridization specifically to the 420 bp band in enterotoxin-positive C. perfringens. On the dot blot membrane, both cpe-specific DNA and oligonucleotide probes were able to hybridize specifically with the corresponding DNA templates but with different efficacy (100% vs 91.1%).     

2种PCR试剂盒定量检测血清HBV DNA含量的比较

目的探讨AMPLIPREP-COBAS TAQMAN法(罗氏COBAS法)和北京鑫诺美迪PCR-荧光探针"一管法"检测血清HBV DNA含量的性能差异。方法采用2种方法同步检测175例乙型肝炎患者血清样本,并将黄疸、溶血和脂血标本作为干扰样本,分析2种方法的相关性、一致性和抗干扰性。取一已知定量为2.24×109IU/ml的标本,用阴性血清做1+9(即1∶10)的稀释,并依次稀释至2.24×10 IU/ml,比较2种方法的线性范围和灵敏性的差异。结果 175份均有数值的标本中,2种试剂检测结果比较差异无统计学意义。2种试剂对黄疸、溶血和脂血标本的定量值影响不大。对于HBV DNA1.70×108IU/ml的样本,罗氏COBAS法结果只显示1.70×108IU/ml,而"一管法"无须稀释仍能准确定量;对于HBV DNA1.00×102IU/ml的样本,"一管法"仅能检测到病毒,而罗氏COBAS法的稳定性和线性更好。结论 PCR-荧光探针"一管法"与进口罗氏COBAS法具有良好的一致性,且省时、省力,价格低廉,适合在我国推广应用。     

原代培养人胎肝细胞体外感染HBV的研究

目的建立HBV感染人胎肝细胞体外培养系统。方法 首先分离、培养人胎肝细胞，然后应用HBV阳性血清感染体外培养的人胎肝细胞；每隔2d收集上清液和肝细胞，应用ELISA,免疫组化法、原位杂交法和斑点杂交法检测上清液和细胞中HBsAg和HBV DNA。结果 上清液中HBsAg在感染后2d～20d均可测出，以感染后4d～16d达高峰(A值在0．22左右)。免疫组化检测细胞中HBsAg呈阳性表达，原位杂交和斑点杂交检测细胞和上清液中HBV DNA也呈阳性表达。结论 HBV在原代培养人胎肝细胞中能稳定复制和表达至少达16d。     

不同方法抽提血清HBV DNA得率的比较

目的：比较不同的HBV DNA抽提方法对PCR产物量的影响,方法：将HBV DNA阳性血清及投入了HBV DNA质粒的HBV DNA阴性血清,分别采用7种不同方法抽提核酸,抽提物作PCR后,产物行琼脂糖凝胶电泳,并对阳性扩增条带进行密度定量,结果：血清直接煮沸法,经典的蛋白酶裂解加酚／氯仿抽提法,蛋白酶裂解加酚／氯仿抽提法省缺乙醇沉淀和柱抽提法的HBV DNA抽提得率分别为75．2％,13．8％,21．9％,用碱变性裂解和蛋白酶裂解后煮沸所得上清液,以及血清直接作为模板,行PCR后不能得到阳性扩增条带。结论：核酸抽提方法选择不当能直接影响基因检测的灵敏度,导致基因定量准确性下降,血清直接煮沸法抽提HBV DNA得率高,操作简便,省时和经济,值得推荐。