Detection of circulating hepatocellular carcinoma cells in peripheral venous blood by reverse transcription-polymerase chain reaction

Objective: To detect circulating hepatocellular carcino-ma by demonstrating hepatocellular carcinoma cells orhepatocyte-associated mRNA in the nuclear cell com-ponent of peripheral blood (PBL).Methods: Peripheral blood (5 ml) samples were ob-tained from 93 patients with hepatocellular carcinoma(HCC) and from 33 control subjects (9 with liver cir-rhosis after hepatitis B,14 with chronic hepatitis B,10with normal liver function). To identify HCC cells inperipheral blood, liver-specific human alpha-fetopro-tein (AFP) mRNA was amplified from total RNA ex-tracted from whole blood by reverse transcription-polymerase chain reaction.Results: AFPmRNA was detected in 50 blood samplesfrom the HCC patients (50/93, 53.8%). In contrast,there were no clinical control patients whose samplesshowed detectable AFPmRNA in PBL. The presence ofAFPmRNA in blood seemed to be correlated with thestage (by TNM classification) of HCC, the serum AFPvalue, and the presence of intrahepatic metastasis,portal vein thrombosis, tumor diameter and/or distantmetastasis. In addition, AFPmRNA was detected in theblood of 21 patients with metastasis at extrahepaticorgans (100%) in contrast to 29 (40.3%)of 72 pa-tients without metastasis.Conclusion: The presence of AFPmRNA in peripheralblood may be an indicator of malignant hepatocytes,which might predict hematogenous spreading metasta-sis of tumor cells in patients with HCC.

Detection of the Pandemic H1N1/2009 Influenza A Virus by a Highly Sensitive Quantitative Real-time Reverse-transcription Polymerase Chain Reaction Assay

A quantitative real time reverse-transcription polymerase chain reaction (qRT-PCR) assay with specific primers recommended by the World Health Organization (WHO) has been widely used successfully for detection and monitoring of the pandemic H1N1/2009 influenza A virus. In this study, we report the design and characterization of a novel set of primers to be used in a qRT-PCR assay for detecting the pandemic H1N1/2009 virus. The newly designed primers target three regions that are highly conserved among the hemagglutinin (HA) genes of the pandemic H1N1/2009 viruses and are different from those targeted by the WHO-recommended primers. The qRT-PCR assays with the newly designed primers are highly specific, and as specific as the WHO-recommended primers for detecting pandemic H1N1/2009 viruses and other influenza viruses including influenza B viruses and influenza A viruses of human, swine, and raccoon dog origin. Furthermore, the qRT-PCR assays with the newly designed primers appeared to be at least 10-fold more sensitive than those with the WHO-recommended primers as the detection limits of the assays with our primers and the WHO-recommended primers were 2.5 and 25 copies of target RNA per reaction, respectively. When tested with 83 clinical samples, 32 were detected to be positive using the qRT-PCR assays with our designed primers, while only 25 were positive by the assays with the WHO-recommended primers. These results suggest that the qRT-PCR system with the newly designed primers represent a highly sensitive assay for diagnosis of the pandemic H1N1/2009 virus infection.

Quantification of Porcine Follicle-stimulating Hormone Receptor Messenger Ribonucleic Acid by Reverse Transcription competitive Polymerase Chain Reaction

An easy and reliable method was developed for construction and quantification of competitive templates, which shared the same sequence as the amplified target DNA except for a 20 bp insertion in the middle by recombinant polymerase chain reaction (PCR). Among the advantages of competitive PCR is that any predictable or unpredictable variable that affects amplification has the same effect on both target and competitor species and that the final ratio of amplified products reflects exactly the initial targets. The utilization of a thermostable reverse transcriptase in the RT step was proposed to overcome the problem of the efficiency of target cDNA synthesis. In addition, to obtain reliable measurements, it was recommended to perform four PCR with amounts of competitive template flanking the concentration of the target mRNA.

Exogenous reference gene normalization for real-time reverse transcription-polymerase chain reaction analysis under dynamic endogenous transcription

Quantitative real-time reverse transcription-polymerase chain reaction （qPCR） is widely used to investigate transcriptional changes following experimental manipulations to the nervous system. Despite the widespread utilization of qPCR, the interpretation of results is marred by the lack of a suitable reference gene due to the dynamic nature of endogenous transcription. To address this inherent deficiency, we investigated the use of an exogenous spike-in mRNA, luciferase, as an internal reference gene for the 2ct normalization method. To induce dynamic transcription, we systemically administered capsaicin, a neurotoxJn selective for C-type sensory neurons expressing the TRPV-1 receptor, to adult male Sprague-Dawley rats. We later isolated nodose ganglia for qPCR analysis with the reference being either exogenous luciferase mRNA or the commonly used endogenous reference 13-111 tubulin. The exogenous luciferase mRNA reference clearly demonstrated the dynamic expression of the endogenous reference. Furthermore, variability of the endogenous reference would lead to misinterpretation of other genes of interest. In conclusion, traditional reference genes are often unstable under physiologically normal situations, and certainly unstable following the damage to the nervous system. The use of exogenous spike-in reference provides a consistent and easily implemented alternative for the analysis of qPCR data.

Detection of hepatocellular carcinoma cells in the peripheral blood with reverse--transcription polymerase chain reaction

In order to detect circulating cells of hepatocellular carcinoma(HCC) in the peripheral blood with reverse transcripition polymerase chain reaction (RT-PCR ), alpha-fetoprotein (AFP ) mRNA was tested in the blood samples of 113 cases of HCC and 69 controls (including 30 cases of liver cirrhosis, 9 cases of metastatic liver cancer and 30 normal subjects). 20/43 (46. 5% ) cases of HCC and 2/30 (6. 7% ) cases of liver cirrhosis are positive and the cases of nletastatic liver cancer and normal controls were negative for human AFP(hAFP) rnRNA. The presence of hAFP mRNA in the peripheral blood seems to be correlated with intrahepatic and distant nletastasls of HCC and portal vein thrombosis. It is concluded that the presence of hAFP mRNA in the peripheral hloocl is an indicator of circulating HCC cells and can be used to diagnose the rnetastasisof HCC through henlatogenous route and RT-PCR amplification of hAFP mRNA is a sensitive and specificprocedure for detecting circulating cells of HCC.

Quantification of mRNA Levels by Fluorescently Labelled Reverse Transcription Competitive PCR

A reproducible,quantitative,non-radioactive method for the analysis of mRNA expression is described.After RNA preparation and cDNA synthesis,the cDNA was co-amplified with an internal standard in the same PCR system.The PCR products containing both targen and internal standard amplificates were electrophoresed and detected on an ABI 377 DNA Sequencer.For each sample,β-actin was also quantified by an identical procedure to compensate for relative differences between samples in the integrity of the individual RNA samples and for variations in reverse transcription.Due to the linear relationship between cDNA content and PCR product ratio of target cDNA template and competitive standard,a single PCR reaction was sufficient for quantification of a sample.The experimental results showed that the method is a mRNA quantitative RT-PCR method with high sensitivity and good reproducibility.It can be used in large-scale accurate quantitative analyses of mRNA expression of any gene.

复合探针实时荧光RT-PCR法检测小儿上呼吸道感染甲型流感病毒的价值

目的 分析小儿上呼吸道感染甲型流感病毒应用复合探针实时荧光反转录聚合酶链反应(RT-PCR)法检测的临床价值。方法选择2023年1月至2023年12月流感监测信息系统两家监测点上呼吸道感染甲型流感病毒感染的患儿80例监测标本进行回顾性分析,均开展复合探针实时荧光RT-PCR法检测,分析其诊断价值。结果 根据监测标本最终诊断结果显示,阳性标本68例、阴性标本12例。经复合探针实时荧光RT-PCR法检出67例,检出率为83.75%,敏感度为95.59%、特异度为83.33%、准确度为93.75%、阳性结果预测值为97.01%、阴性结果预测值为76.92%;批间批内变异系数均小于5%。结论 小儿上呼吸道感染甲型流感病毒应用复合探针实时荧光RT-PCR技术具有较高的敏感度、特异度及准确度,且检查结果快速,可为小儿上呼吸道感染甲型流感病变提供可靠的诊断,有利于制订合理的治疗方案。

饮食习惯与肥胖患儿性早熟的相关性分析

目的探讨饮食习惯与肥胖患儿性早熟的相关性分析。方法选取苏州市吴中人民医院2019年3月至2022年3月期间收治的72例性早熟肥胖患儿作为观察组,另选取同期体检的健康肥胖儿童71例作为常规组。采用实时-逆转录荧光定量聚合酶链反应(RT-qPCR)检测两组外周血miR-125b水平,分析患儿饮食习惯。通过比较两组肥胖儿童的外周血miR-125b、饮食习惯,采用Logistic回归分析法分析外周血miR-125b、饮食习惯与肥胖患儿性早熟的关系。结果观察组外周血miR-125b表达水平高于常规组,差异有统计学意义(P<0.05)。观察组饮食没规律、荤多素少、高添加剂食品占比均高于常规组,差异有统计学意义(P<0.05)。观察组女性患儿、不良饮食习惯占比高于常规组,且经多因素分析显示外周血miR-125b表达水平、女性、不良饮食习惯是肥胖患儿性早熟的独立危险因素,差异有统计学意义(P<0.05)。结论肥胖患儿性早熟外周血miR-125b表达水平高于健康肥胖儿童,不良饮食习惯高于健康肥胖儿童,外周血miR-125b表达水平偏高、不良饮食习惯偏低均为肥胖患儿性早熟的影响因素。

帕利亚姆病毒实时荧光定量RT-PCR检测方法的建立与应用

本研究拟建立帕利亚姆病毒(Palyam virus,PALV)血清型特异性实时荧光定量RT-PCR(qRT-PCR)方法用于临床样本或媒介中PALV血清型鉴定。根据我国流行PALV毒株的基因节段2序列,设计扩增引物和TaqMan探针,建立PALV血清型特异型qRT-PCR方法,对方法的特异性、灵敏性与重复性进行评估;以我国分离的28株PALV和90份核酸阳性血液样本评估检测方法的可靠性;利用建立的方法对采集库蠓样本中携带的PALV进行血清型鉴定。结果显示,建立的PALV血清型qRT-PCR检测方法具有良好的特异性与灵敏性,可检出核酸拷贝数下限在22至28 copies·μL^(-1)。对28株PALV的qRT-PCR检测结果与病毒测序鉴定结果一致;对PALV不同感染阶段哨兵动物血液(90份)中的qRT-PCR鉴定结果与分离病毒的血清型鉴定结果一致;建立的方法可准确鉴定库蠓中携带PALV的血清型。本研究建立的PALV血清型qRT-PCR定型方法具有良好的特异强、敏感性与重复性,可用于PALV感染动物与媒介中PALV血清型的鉴定,具有良好的应用价值。

新型冠状病毒亚基因组RNA检测方法的建立及性能评估

目的建立检测新型冠状病毒(新冠病毒)亚基因组RNA(subgenomic RNA,sgRNA)的方法,并对所建立的方法进行性能评估。方法根据新型冠状病毒sgRNA序列设计引物和探针,建立检测sgRNA的实时荧光逆转录PCR(reverse transcription polymerase chain reaction,RT-PCR)方法,对所建立的方法进行优化,包括引物、探针的浓度及比例、延伸温度、反应体积和模板量。并对所建立的方法进行性能评估,包括最低检测限、灵敏度、特异性和重复性。对临床样本进行新冠病毒sgRNA和基因组RNA(genomic RNA,gRNA)检测,并对检测结果进行分析。结果建立了检测新冠病毒sgRNA的RT-PCR方法。所建方法的最低检测限为100 copies/mL,对常见病原体的检测结果均为阴性。对高、中、低浓度样本sgRNA进行检测,CV均<5%。115例疑似新冠病毒感染者的咽拭子样本sgRNA为阳性(115/330,阳性率为34.85%)。gRNA-N Ct值<30时,sgRNA-N的阳性率为100.00%;gRNA-N的Ct值介于30~32时,sgRNA-N的阳性率为68.75%;gRNA-N的Ct值介于32~35时,sgRNA-N的阳性率为44.44%;gRNA-N的Ct值>35时,sgRNA-N均为阴性。结论建立了新冠病毒sgRNA的RT-PCR检测方法,方法灵敏、特异、重复性好。

Identifying the stability of housekeeping genes to be used for the quantitative real-time PCR normalization in retinal tissue of streptozotocin-induced diabetic rats

AIM:To investigate the stability of the seven housekeeping genes:beta-actin(ActB),glyceraldehyde-3-phosphate dehydrogenase(GAPDH),18s ribosomal unit 5(18s),cyclophilin A(CycA),hypoxanthine-guanine phosphoribosyl transferase(HPRT),ribosomal protein large P0(36B4)and terminal uridylyl transferase 1(U6)in the diabetic retinal tissue of rat model.METHODS:The expression of these seven genes in rat retinal tissues was determined using real-time quantitative reverse transcription polymerase chain reaction(RT-qPCR)in two groups;normal control rats and streptozotocininduced diabetic rats.The stability analysis of gene expression was investigated using geNorm,NormFinder,BestKeeper,and comparative delta-Ct(ΔCt)algorithms.RESULTS:The 36B4 gene was stably expressed in the retinal tissues of normal control animals;however,it was less stable in diabetic retinas.The 18s gene was expressed consistently in both normal control and diabetic rats’retinal tissue.That this gene was the best reference for data normalisation in RT-qPCR studies that used the retinal tissue of streptozotocin-induced diabetic rats.Furthermore,there was no ideal gene stably expressed for use in all experimental settings.CONCLUSION:Identifying relevant genes is a need for achieving RT-qPCR validity and reliability and must be appropriately achieved based on a specific experimental setting.

基于直扩RT-PCR技术的寨卡病毒快速检测方法的建立

目的建立基于直扩实时荧光定量逆转录聚合酶链反应(RT-PCR)技术的寨卡病毒快速检测方法。方法采用特殊功能的DNA聚合酶,以及优选PCR增强剂,以此建立直扩RT-PCR技术的寨卡病毒快速检测5种样本(全血、血清、唾液、咽拭子和尿)的方法。结果5种样本检测限分别为血清103 PFU/mL,尿、咽拭子和唾液102 PFU/mL,全血104 PFU/mL,标准曲线的拟合优度的可决系数均在0.98以上,扩增效率均在90%~110%;寨卡病毒核酸成功扩增,非寨卡病毒核酸均未能扩增;尿、全血和唾液样本的重复性实验中106 PFU/mL和102 PFU/mL两个浓度的6个重复Ct值的变异系数均<5%。该研究建立的直扩RT-PCR技术的寨卡病毒检测方法与常规RT-PCR技术的检测结果一致,8个寨卡病毒样本,均只检测出2个血清样本,其余62个非寨卡病毒样本及12个阴性样本均未得到扩增。结论成功建立基于直扩RT-PCR技术的寨卡病毒快速检测方法,该方法简便快捷且灵敏度高、特异度强。

RT-PCR法在沙门菌检测及血清分型鉴定中的应用价值研究

目的:探讨反转录-聚合酶链反应(RT-PCR)法在沙门菌检测及血清分型鉴定中的应用价值。方法:选择2022年8月至2024年1月本疾控中心收治的456例腹泻患者的粪便标本,均行细菌培养和RT-PCR检测,记录RT-PCR鉴定沙门菌血清分型结果,以细菌培养结果作为金标准,分析RT-PCR鉴定沙门菌的价值及其与细菌培养的一致性,对比细菌培养、RT-PCR鉴定沙门菌的费用及操作时间。结果:456例腹泻中经细菌培养共检出沙门菌78株,RT-PCR检出85株,RT-PCR检测敏感度为97.44%(76/78),特异度为96.83%(366/378),准确度为96.93%(442/456),阳性预测值为89.41%(76/85),阴性预测值为99.46%(366/368);RT-PCR鉴定沙门菌结果与细菌培养一致性较高(kappa值=0.897,P<0.001);RT-PCR鉴定结果与细菌培养完全一致有73株,符合率为93.59%,其中里森沙门菌、鼠伤寒沙门菌、德尔卑沙门菌、姆班达卡沙门菌4种优势血清型结果完全一致,而与细菌培养鉴定不一致菌株5株;RT-PCR鉴定沙门菌操作时间为(0.30±0.07)天,费用(100.22±6.52)元,细菌培养鉴定沙门菌的操作时间为(2.82±0.25)天,费用为(300.52±12.16)元,RT-PCR鉴定沙门菌的费用及操作时间均低于细菌培养,差异有统计学意义(P<0.001)。结论:RT-PCR法可准确检出沙门菌,判断沙门菌血清分型,与细菌培养结果具有较高的一致性,且操作用时短、所需费用低,可应用于沙门菌检测。

酒泉市猪繁殖与呼吸综合征的流行病学监测和分析

为掌握酒泉市猪繁殖与呼吸综合征(PRRS)的流行情况,本试验在酒泉市五个农业县市采集638份样品,采用反转录-聚合酶链式反应(荧光RT-PCR)方法进行核酸检测,对不同地域、不同生长期、不同饲养模式的流行情况进行分析。结果显示,638份样品共检测出PRRS核酸阳性样品29份,PRRS阳性感染率为4.55%。不同地域PRRS阳性感染率介于0-7.95%;屠宰场、规模场、散养户PRRS阳性感染率分别为0、2.96、6.82%;种公猪、育肥猪、仔猪、母猪PRRS阳性感染率分别为0、3.1、5.38、6.36%。结果表明,酒泉市PRRS呈散发流行,规模养殖场标准化高,饲养管理模式先进PRRS阳性感染率低,此病仔猪和母猪更容易感染,本试验将对我市PRRS综合防控提供技术支撑。

Abnormal expression of VEGF and its gene transcription status as diagnostic indicators in patients with non-small cell lung cancer

Objective Angiogenesis is known to be essential for the survival,growth,invasion,and metastasis of lung cancer cells. Vascular endothelial growth factor(VEGF) is an important factor regulating angiogenesis of non-small cell lung cancer(NSCLC); however,its pathologic features and significance are unclear. In this study,the tissue VEGF expression levels and its gene transcriptional status,as well as circulating VEGF levels,were investigated in patients with lung disease. Methods VEGF protein and m RNA expression levels in 38 lung tissue samples were analyzed by immunohistochemistry and reverse transcription-polymerase chain reaction(RT-PCR),respectively. Circulating VEGF levels were detected quantitatively by an enzyme linked immuno-sorbent assay. Results The level of VEGF expression was significantly higher in lung cancer tissue than in the corresponding paracancerous or non-cancerous tissues. The average level of VEGF-positive staining was 76% in tissue samples from NSCLC patients; the levels were 89% in tissue samples from stage III patients and 92% in stage IV patients. High VEGF expression was also evident in cases with lymph node metastasis(84%),distant metastasis(90%),and lower differentiation degree(89%). VEGF m RNA in cancerous tissues was represented predominantly by the VEGF121 and VEGF165 isoforms. Circulating VEGF levels were significantly higher in NSCLC patients [(840 ± 324) pg/m L] than in patients with benign lung diseases [(308 ± 96) pg/m L] or in healthy individuals serving as controls [(252 ± 108) pg/m L]. Conclusion The over-expression of lung VEGF and its gene transcription status should be useful molecular indicators for NSCLC diagnosis.

Novel flutamide regulated genes in the rat veritral prostate： differential modulation of their expression by castration and flutamide treatments

Aim： To identify flutamide regulated genes in the rat ventral prostate. Methods： Total RNA from ventral prostates of control and flutamide treated rats were isolated. Differentially expressed transcripts were identified using differential display reverse transcriptase polymerase chain reaction. The effect of castration on the expression of flutamideregulated transcripts was studied. Results： We have identified β2-microglobulin, cytoplasmic FMR1 interacting protein 2 and pumilio 1 as flutamide induced and spermine binding protein and ribophorin Ⅱ as flutamide repressed targets in the rat ventral prostate. Although flutamide treatment caused an induction of pumilio 1 rnRNA, castration had no effect. Conclusion： Castration and flutamide treatments exert differential effects on gene expression. Flutamide might also have direct AR independent effects, which might have implications in the emergence of androgen independent prostate cancer and the failure of flutamide therapy.

猪德尔塔冠状病毒RT-nPCR检测方法的建立与N基因变异分析

建立一种基于猪德尔塔冠状病毒(PDCo V)N基因的RT-n PCR检测方法,对陕西省猪群PDCo V感染情况进行流行病学调查,分析PDCo V流行毒株N基因变异情况。通过病毒分离、检测引物设计、反应体系与条件优化、灵敏性试验和特异性试验,建立了PDCo V RT-nPCR检测方法,并对N基因片段进行序列分析。结果表明:建立的RT-n PCR方法能够扩增出303 bp的N基因目的片段,检测单链c DNA的极限为2.0194×10^(-3)ng·μL^(-1),该方法检测PEDV、TGEV、PRo V、CSFV与PRRSV均无交叉反应,特异性良好;陕西省猪场184份样品检测结果显示,PDCo V阳性率为6.52%(12/184);N基因序列分析发现,获得的HY2019、QLS2020的N基因片段同源性为99.0%,提示可能为同一来源;进化树分析发现,HY2019、QLS2020与我国四川株SCNC201705、Sichuan2017、Sichuan2019同处于一个小的进化分支上,且均存在168~179位“TGTCTGTCTCTA”共12个核苷酸缺失,推测陕西株与四川株高度同源,可能起源于早期四川毒株。

南疆某规模化猪场猪瘟病原与抗体的检测分析

研究旨在调查南疆某规模化猪场免疫猪群的猪瘟抗原与抗体水平,为制定适应当地生产条件的免疫程序提供参考。试验运用酶联免疫吸附试验(ELISA)对该场免疫猪群的480份血清样品进行抗体检测与分析,并采用反转录-聚合酶链式反应(RT-PCR)对采集的24份猪瘟疑似病料进行抗原检测。结果显示,对随机采集的480份血清样品进行猪瘟抗体检测,其中449份为阳性样品,阳性率为93.5%;不同类别群体中以母猪的抗体阳性率最高,为97.2%;2~4胎母猪与5~6胎母猪的抗体阳性率为97.8%;22~28 d的阳性率最低,为76.9%;36~50 d的仔猪抗体阳性率最高,为92.3%。对采集的24份猪瘟疑似病料进行抗原检测,显示均为阴性。研究表明,该规模化猪场的猪瘟免疫情况良好,未出现感染情况。

蛹虫草退化梯度的建立及退化过程中相关分子机制的变化

该研究以实验室人工栽培模拟工业生产工艺,对蛹虫草菌株ZGCM进行重复传代培养,人为建立了1至7代的菌种退化梯度株系,以探究蛹虫草退化过程中的形态变化规律及其内在分子机制的变化。实验结果表明,ZGCM菌株自第2代开始退化,至第6代基本不产生子实体。培养基残糖含量随退化梯度菌种代际数目的上升而呈下降趋势,第5代与第1代相比下降了62.40%。培养基残余蛋白质含量在第2代下降后出现回升,提示蛹虫草菌株随着传代次数的上升,吸收外界氮源的能力持续下降。以qRT-PCR法测定过往报道中发现的14个转录水平变化趋势与蛹虫草退化代际数目呈线性相关的基因,结果表明仅有CCM_04090基因的表达量呈上升趋势,第5代与第1代相比提高了39.60%,与过往报道一致。其他基因均无显著变化。以HPLC法测定静置液体发酵液中的虫草素含量,发现其随着传代次数的上升而下降。静置发酵30d时,第5代与第1代相比虫草素产量下降了74.56%。结果表明蛹虫草菌株退化会对子实体产量和虫草素含量等两大产品品质核心因素造成负面影响。

寨卡病毒核酸检测技术研究进展

寨卡病毒(ZIKV)为黄病毒科黄病毒属的一种单链RNA病毒,主要通过埃及伊蚊和白纹伊蚊传播,也可通过血液、性、母婴等途径传播。传播ZIKV的蚊虫在我国分布广泛,同时,随着全球化的发展,世界各国人员往来日益频繁,ZIKV在我国有潜在传播的可能性。核酸检测技术是实验室快速检测的有效手段,对预防和控制ZIKV传播具有重要意义。本文介绍了ZIKV基因组结构,并对ZIKV核酸检测的样本特点及方法进展作一综述。