Rapid quantification of semen hepatitis B virus DNA by real-time polymerase chain reaction

AIM： To examine the sensitivity and accuracy of real-time polymerase chain reaction （PCR） for the quantification of hepatitis B virus （HBV） DNA in semen. METHODS： Hepatitis B viral DNA was isolated from HBV carriers＇ semen and sera using phenol extraction method and QIAamp DNA blood mini kit （Qiagen, Germany）. HBV DNA was detected by conventional PCR and quantified by TaqMan technology-based real-time PCR （quantitative polymerase chain reaction （qPCR））. The detection threshold was 200 copies of HBV DNA for conventional PCR and 10 copies of HBV DNA for real time PCR per reaction. RESULTS： Both methods of phenol extraction and QIAamp DNA blood mini kit were suitable for isolating HBV DNA from semen. The value of the detection thresholds was 500 copies of HBV DNA per mL in the semen. The viral loads were 7.5×10^7 and 1.67×10^7 copies of HBV DNA per mL in two HBV infected patients＇ sera, while 2.14×10^5 and 3.02×10^5 copies of HBV DNA per mL in the semen. CONCLUSION： Real-time PCR is a more sensitive and accurate method to detect and quantify HBV DNA in the semen.

Human papillomavirus 16 physical status detection in preinvasive and invasive cervical carcinoma by multiplex real-time polymerase chain reaction

Objective： To explore an ideal approach for detecting the physical status of HPV-16 in clinic use and to investigate the integrated HPV-16 in CINs and cervical cancer. Methods： Multiplex real-time PCR method was established to quantify the copy numbers of E2 and E6 genes （E2/E6） for analysis of the physical status of HPV-16 DNA and this assay was compared to Southern blot analysis. HPV-16-containing paraffin-embedded tissues including 49 CINs and 51 cervical squamous cancers were detected using the method. Results： （1） The cutoff ratio of E2/E6 to distinguish pure episomal from mixed HPV-16, was 0.81 in the multiplex real-time PCR; （2） The agreement rate between multiplex real-time PCR and Southern blot was 81.5% （the Kappa statistic was 0.844, P〈0.001）; （3） HPV-16 DNA existed in an episomal form in 57.1% and mixed form in 42.9% of CIN I lesions; The concomitant form of HPV-16 （〉70%） constituted the majodty in CIN Ⅱ and CIN Ⅲ; HPV-16 DNA mostly integrated into the host chromosome （s） in squamous cervical cancers （68.6%）; （4） The incidence of HPV-16 integration was increased with the degree of cervical lesions; （5） The frequency of pure integrated HPV-16 in stage Ⅱ＋Ⅲ （88%） was significantly higher than that in stage Ⅰ （33.3%）. Conclusion： （1） Mutiplex real-time PCR provides a rapid, sensitive and reliable method for clinic detection of the physical state of HPV-16 DNA; （2） The integration of the HPV-16 DNA is a very eady and important event in the progression from preinvasive to invasive cervical cancer; （3） The pure integrated status of HPV-16 in cervical cancer may be associated with poor prognosis of cervical cancer, but further study will be needed to prove its prognostic significance.

Expression of cellular fibronectin mRNA in adult periodontitis and peri-implantitis: a real-time polymerase chain reaction study

Cellular fibronectin （cFn） is a type of bioactive non-collagen glycoprotein regarded as the main substance used to maintain periodontal attachment. The content of cFn in some specific sites can reflect the progress of periodontitis or peri-implantitis. This study aims to evaluate the expression of cFn messenger RNA （mRNA） in tissues of adult periodontitis and peri-implantitis by real-time fluorescent quantitative polymerase chain reaction （PCR） and to determine its clinical significance. A total of 30 patients were divided into three groups of 10： healthy, adult periodontitis and peri-implantitis. Periodontal tissue biopsies （1 mmx I mmx I mm） from each patient were frozen in liquid nitrogen. Total RNA was extracted from these tissues, and the content, purity and integrity were detected. Specific primers were designed according to the sequence, and the mRNA expression levels of cellular fibronectin were detected by real-time PCR. The purity and integrity of the extracted total RNA were both high, and the specificity of amplified genes was very high with no other pollution. The mRNA expression of cFn in the adult periodontitis group （1.526＋0.441） was lower than that in the healthy group （3.253＋0.736）. However, the mRNA expression of cFn in the peri-implantitis group （3.965＋0.537） was significantly higher than that in the healthy group. The difference revealed that although both processes were destructive inflammatory reactions in the periodontium, the pathomechanisms were different and the variation started from the transcription level of the cFn gene.

Real-time polymerase chain reaction for the diagnosis of necrotizing herpes stromal keratitis

AIM： To design, optimize and validate a rapid,internally controlled real-time polymerase chain reaction（RT-PCR） test for herpes simplex virus（HSV） in the diagnosis of necrotizing herpes stromal keratitis.· METHODS： Tears alone or together with corneal epithelium scrapings from 30 patients（30 eyes）suspected of necrotizing herpes stromal keratitis were tested for HSV DNA by RT-PCR. The samples were collected during the first visit and then on the subsequent 7, 14, 28, 42, and 56 d. The symptoms of the patients were scored before treatment to determine the correlation between HSV concentration in the corneal epithelium scrapings and clinical scores.·RESULTS： The positive rate（46.4%） in the corneal epithelium group before the therapy was significantly higher than that（13.3%） in the tears group（P =0.006）.There were 13 positive HSV patients before the therapy,the concentration of HSV DNA in corneal epithelium scrapings group was significantly higher than that in the tears group（paired t-test, P =0.0397）. Multilevel mixedeffects model analysis showed that the difference between the corneal epithelium scrapings group and the tears group was statistically significant（P =0.0049）. The Spearman rank correlation analysis indicated a positive correlation between the HSV concentration in the corneal epithelium scrapings and clinical scores before the treatment（r =0.844, P〈 0.0001）.· CONCLUSION： RT-PCR appears to be a powerful molecular tool for the diagnosis of necrotizing herpes stromal keratitis.

Rapid genotyping of human rotavirus using SYBR green real-time reverse transcription-polymerase chain reaction with melting curve analysis

AIM: To develop a real-time reverse transcriptionpolymerase chain reaction(RT-PCR) assay to genotype rotavirus(G and P) in Alberta from January 2012 to June 2013. METHODS: We developed and validated a different approach to perform rotavirus G and P genotyping using a two-step SYBR green RT-PCR(rt-g PCR) by selecting genotype-specific primers of published conventional RT nested PCR(cn RT-PCR) assay and optimizing the amplification conditions. c DNA was first synthesized from total RNA with Super Script? Ⅱ reverse transcriptase kit followed by amplication step using monoplex SYBR green real-time PCR. After the PCR reaction, melting curve analysis was used to determine specific genotype. Sixteen samples previously genotyped using cn RT-PCR were tested using the new assay and the genotyping results were compared as sensitivity analysis. Assay specificity was evaluated by testing other gastroenteritis viruses with the new assay. The amplicon size of each available genotype was determined by gelelectrophoresis and DNA sequences were obtained using Sanger-sequencing method. After validation and optimization, the new assay was used to genotype 122 pediatric clinical stool samples previously tested positive for rotavirus using electron microscopy between January2012 and June 2013.RESULTS: The new rt-g PCR assay was validated and optimized. The assay detected G1 to G4, G9, G12 and P[4] and P[8] that were available as positive controls in our laboratory. A single and clear peak of melting curve was generated for each of specific G and P genotypes with a Tm ranging from 80 ℃ to 82 ℃. The sensitivity of rt-g PCR was comparable to cn RT-PCR with 100% correlation of the 16 samples with known G and P genotypes. No cross reaction was found with other gastroenteritis viruses. Using the new rt-g PCR assay, genotypes were obtained for 121 of the 122 pediatric clinical samples tested positive for rotavirus: G1P[8](42.6%), G2P[4](4.9%), G3P[8](10.7%), G9P[8](10.7%), G9P[4](6.6%), G12P[8](23.0%), and unknown GP[8](0.8%). For the first time, G12 rotavirus strains were found in Alberta and G12 was the second most common genotype during the study period. Gel electrophoresis of all the genotypes showed expected amplicon size for each genotype. The sequence data of the two G12 samples along with other genotypes were blasted in NCBI BLAST or analyzed with Rota C Genotyping tool(http://rotac.regatools.be/). All genotyping results were confirmed to be correct.CONCLUSION: rt-g PCR is a useful tool for the genotyping and characterization of rotavirus. Monitoring of rotavirus genotypes is important for the identification of emerging strains and ongoing evaluation of rotavirus vaccination programs.

Primary application of a real-time quantitative polymerase chain reaction for the detection of human breast cancer related novel gene-Metadherin expression

Objective:The aim of this study was to detect the expression level of Metadherin (MTDH) in peripheral blood of the breast cancer patients by real-time fluorescence quantitative polymerase chain reaction (PCR),and to explore the relationship between expression of Metadherin gene in the patients peripheral blood and the clinic-pathological features in breast cancer. Methods:Real-time fluorescence quantitative polymerase chain reaction was employed to determine the expression level of Metadherin gene in 80 peripheral blood samples of breast cancer patients and healthy donors. Results:The expression of Metadherin gene in breast cancer patients peripheral blood were positive,in which 34 breast cancer patients were highly expressed,accounting for 55.7%,while the expression of Metadherin gene in normal females peripheral blood were negative,there was statistical significance (Ratio = 2.02±0.81,P < 0.05); Ratio of the Metadherin expression in breast cancer patients peripheral blood and the glyceraldehyde-3-phosphate dehydrogenase expression was 1.15 ± 0.36. REST software analysis showed that the expression of Metadherin gene was significantly up-regulated in breast cancer. Conclusion:The SYBR Green I quantitative real-time polymerase chain reaction method can successfully detect the expression level of Metadherin gene. Expression level of Metadherin gene in breast cancer patients peripheral blood is closely related to survival,and it maybe involved in the development of breast cancer and used as an indicator of prognosis.

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.

Real-time Fluorescence PCR Method for Detection of Burkholderia glumae from Rice

Burkholderia glumae causing seedling rot and grain rot of rice was listed as a plant quarantine disease of China in 2007. It＇s quite necessary to set up effective detection methods for the pathogen to manage further dispersal of this disease. The present study combined the real-time PCR method with classical PCR to increase the detecting efficiency, and to develop an accurate, rapid and sensitive method to detect the pathogen in the seed quarantine for effective management of the disease. The results showed that all the tested strains of B. glumae produced about 139 bp specific fragments by the real-time PCR and the general PCR methods, while others showed negative PCR result. The bacteria could be detected at the concentrations of 1×10^4 CFU/mL by general PCR method and at the concentrations below 100 CFU/mL by real-time fluorescence PCR method. B. glumae could be detected when the inoculated and healthy seeds were mixed with a proportion of 1：100.

Diagnosis of anorectal tuberculosis by polymerase chain reaction,GeneXpert and histopathology in 1336 samples in 776 anal fistula patients

BACKGROUND The association of tuberculosis(TB)with anal fistulas can make its treatment quite difficult.The main challenge is timely detection of TB in anal fistulas and its proper management.There is little data available on diagnosis and management of TB in anal fistulas.AIM To detect TB in fistula-in-ano patients were analyzed in different methods utilized.METHODS A retrospective analysis of different methods,polymerase chain-reaction(PCR),GeneXpert and histopathology(HPE),utilized to detect tuberculosis in fistula-inano patients,treated between 2014-2020,was performed.The sampling was done for tissue(fistula tract lining)and pus(when available).The detection rate of various tests to detect TB and prevalence rate of TB in simple vs complex fistulae were studied.RESULTS In 1336 samples(776 patients)tested,TB was detected in 133 samples(122 patients).TB was detected in 52/703(7.4%)samples tested by PCR-tissue,in 77/331(23.2%)samples tested by PCR-pus,3/197(1.5%)samples tested with HPE-tissue and 1/105(0.9%)samples tested by GeneXpert.To detect TB,PCRtissue was significantly better than HPE-tissue(52/703 vs 3/197 respectively)(P=0.0012,significant,Fisher’s exact test)and PCR-pus was significantly better than PCR-tissue(77/331 vs 52/703 respectively)(P<0.00001,significant,Fisher’s exact test).TB fistulas were more complex than non-tuberculous fistulas[78/113(69%)vs 278/727(44.3%)respectively](P<0.00001,significant,Fisher’s exact test)but the overall healing rate was similar in tuberculous and non-tuberculous fistula groups[90/102(88.2%)vs 518/556(93.2%)respectively](P=0.10,not significant,Fisher’s exact test).CONCLUSION This is the largest study of anorectal TB to be published.The detection of TB by polymerase chain-reaction was significantly higher than by histopathology and GeneXpert.Amongst polymerase chain-reaction,pus had a higher detection rate than tissue.TB fistulas were more complex than non-tuberculous fistulas but aggressive diagnosis and meticulous treatment led to comparable overall success rates in both groups.

Comparison of Abbott and Da-an real-time PCR for quantitating serum HBV DNA

AIM: To compare the performance of the Da-an real-time hepatitis B virus (HBV) DNA assay and Abbott RealTime HBV assay.

Analysis of hepcidin expression: In situ hybridization and quantitative polymerase chain reaction from paraffin sections

AIM: To establish methods for quantitative polymerase chain reaction (PCR) for hepcidin using RNAs isolated from paraffin-embedded sections and in situ hybridization of hepatocellular carcinoma (HCC). METHODS: Total RNA from paraffin-embedded sections was isolated from 68 paraffin-embedded samples of HCC. Samples came from 54 male and 14 female patients with a mean age of 66.8 ± 7.8 years. Quantitative PCR was performed. Immunohistochemistry and in situ hybridization for hepcidin were also performed. RESULTS: Quantitative PCR for hepcidin using RNAs isolated from paraffin-embedded sections of HCC was performed successfully. The expression level of hepcidin mRNA in cancer tissues was significantly higher than that in non-cancer tissues. A method of in situ hybridization for hepcidin was established successfully, and this demonstrated that hepcidin mRNA was expressed in non-cancerous tissue but absent in cancerous tissue. CONCLUSION: We have established novel methods for quantitative PCR for hepcidin using RNAs isolated from paraffin-embedded sections and in situ hybridization of HCC.

Use of real-time polymerase chain reaction for the diagnosis of Pneumocystis pneumonia in immunocompromised patients： a meta-analysis

Background The diagnosis of Pneumocystis pneumonia （PCP） in immunocompromised patients is still challenging today due to the absence of an in vitro culture system and the low diagnostic accuracy of microscopic examinations. Herein, we performed a meta-analysis to evaluate the accuracy of real-time polymerase chain reaction （PCR） in the diagnosis of PCP. Methods We searched Web of Knowledge and Medline from 1990 to May 2010 for studies reporting diagnostic accuracy data regarding the use of real-time PCR in the diagnosis of PCP in immunocompromised patients. Results Ten individual studies were included. Overall, the sensitivity of real-time PCR was 97% （95% CI： 93%-99%）; the specificity was 94% （95% CI： 90%-96%）. The area under the HSROC curve （95% CO for real-time PCR was 0.99 （0.97-0.99）. In a subgroup analysis regarding studies involving HIV patients among the study population, the sensitivity and specificity were 97% （95% CI： 93%-99%） and 93% （95% CI： 89%-96%）, respectively. Regarding studies using Bronchoalveolar lavage （BAL） samples only： sensitivity =98% （95% CI： 94%-99%）; specificity =93% （95% CI： 89%- 96%）, respectively. Regarding studies using microscopy as a reference standard： sensitivity =97% （95% CI： 92%-99%）; specificity =93% （95% CI： 88%-96%）. However, high between-study statistical heterogeneity was observed in all analyses. Conclusions Real-time PCR has a good diagnostic accuracy and may provide a useful adjunctive tool for the diagnosis of PCP in immunocompromised patients. Further studies are needed in order to identify any differences in the diagnostic performance of real-time PCR in HIV and non-HIV immunocompromised patients.

Micro-droplet Digital Polymerase Chain Reaction and Real-Time Quantitative Polymerase Chain Reaction Technologies Provide Highly Sensitive and Accurate Detection of Zika Virus

The establishment of highly sensitive diagnostic methods is critical in the early diagnosis and control of Zika virus(ZIKV)and in preventing serious neurological complications of ZIKV infection. In this study, we established micro-droplet digital polymerase chain reaction(ddPCR) and real-time quantitative PCR(RT-qPCR) protocols for the detection of ZIKV based on the amplification of the NS5 gene. For the ZIKV standard plasmid, the RT-qPCR results showed that the cycle threshold(Ct) value was linear from 10~1 to 10~8 copy/l L, with a standard curve R^2 of 0.999 and amplification efficiency of 92.203%;however, a concentration as low as 1 copy/l L could not be detected. In comparison with RT-qPCR, the dd PCR method resulted in a linear range of 10~1–10~4 copy/l L and was able to detect concentrations as low as 1 copy/l L. Thus, for detecting ZIKV from clinical samples, RT-qPCR is a better choice for high-concentration samples(above 10~1 copy/l L),while ddPCR has excellent accuracy and sensitivity for low-concentration samples. These results indicate that the ddPCR method should be of considerable use in the early diagnosis, laboratory study, and monitoring of ZIKV.

乙肝病毒基因型与肝脏病理改变的关系

目的:探讨乙型肝炎病毒基因型与慢性乙型肝炎患者肝脏病理变化的关系.方法:应用乙肝病毒型特异性引物采用巢式聚合酶链反应(PCR)和荧光定量聚合酶链反应(FQ-PCR),对北京佑安医院住院92例慢性乙型肝炎患者进行乙型肝炎病毒基因型及亚型分析,参照2000年《病毒性肝炎防治方案》对慢性肝炎进行病理分级、分期诊断.结果:92例慢性乙型肝炎患者中HBV基因型分布为B型17例(B2亚型),B/C混合型17例(B2/Ca亚型),C型58例(Ca亚型).17例HBV B型感染患者中病理诊断肝脏炎症活动分级为G1-G3期分别为35.29%,58.82%,5.88%;肝脏纤维化程度分级为S1-3级分别为58.82%,29.41%,11.76%,17例HBV B/C型感染患者中病理诊断肝脏炎症活动分级为G1-G3期35.29%,52.94%,11.76%;肝脏纤维化程度分级为S1-3级23.52%,52.94%,23.52%,58例HBV C型感染患者中病理诊断肝脏炎症活动分级为G1-G4期31.03%,24.14%,36.21%,8.62%;肝脏纤维化程度分级为S1-4级25.86%,39.66%,5.17%,29.31%;HBV三组不同基因型的慢性乙型肝炎患者肝组织病理检查有统计学意义(x^2=15.13,P<0.01).HBV B型与B/C型感染患者年龄在21-30岁组58%-76%,31-40岁组17.6%-29.4%,C型感染患者年龄在21-30岁组25%,31-40岁组46.6%,40岁以上有24.24%;不同HBV基因型感染患者的年龄分布有显著性差异(x^2=9.54,P<0.05).结论:慢性乙型肝炎患者HBV基因型中C型比例明显高于B型与B/C型.HBV C型患者肝脏病理变化较B型与B/C型严重.不同HBV基因型感染患者的年龄分布不同.

IL-4和IL-13在溃疡性结肠炎中的表达

目的探讨Th2类细胞因子IL4和IL13在溃疡性结肠炎中的作用。方法收集30例经内镜检查证实的UC患者结肠黏膜和血清标本,20例性别、年龄相匹配的同期大肠息肉患者(取其正常组织)作为对照组。用RTPCR法和酶联免疫吸附法(ELISA)检测IL4及IL13的mRNA表达及其血清含量。结果轻度UC患者IL4和IL13的mRNA表达与对照组比较无统计学意义(P>0.05),中重度UC患者IL4和IL13的肠黏膜表达明显下降(P<0.05)与对照组比较,二者血清含量未见明显区别(P>0.05)。结论IL4和IL13在UC的发病中起重要作用。

石家庄汪洋沟地区抗生素、抗性细菌和抗性基因污染特征

以石家庄汪洋沟地区为研究对象，采用高效液相色谱-质谱法（HPLC-MS）、平板计数、实时荧光定量（qPCR）法分别对地表水、地下水及沉积物样品中的抗生素、抗性细菌和抗性基因进行定量分析。结果表明，汪洋沟地区四环素类抗生素总体含量高于磺胺类抗生素，水体中ρ（Σ四环素）为5.81×101-3.87×105 ng·L-1，ρ（Σ磺胺）为1.02×101-5.37×103 ng·L-1；沉积物中w（Σ四环素）为4.28×101-1.63×105 ng·g-1，w（Σ磺胺）为1.18×101-1.68×104 ng·g-1；水体中四环素的抗性细菌数量为4.00×101-2.13×104 CFU·mL-1，磺胺抗性细菌数量为6.67×101-7.34×105 CFU·mL-1；水体中抗性细菌含量比沉积物中低3-4个数量级。样品中检出的5种四环素类抗性基因（tetA、tetB、tetE、tetW和tetZ）、2种磺胺类抗性基因（sul1，sul2）及2种整合子基因（int1，int2）的相对表达量较高，其中tetA及sul1为汪洋沟地区的优势抗性基因，相对表达量均高于1.58×10-2。主成分分析结果表明ARGs的含量分布受不同污染源和复杂的水质特征的影响。从te t（B）基因的系统发育分析结果可以看出，水质的变化会导致抗性菌种存在差异。与国内外河流相比，汪洋沟抗生素含量处于较高污染水平，抗性基因污染也较为严重。

基因重排检测技术的建立及其在淋巴瘤诊断中的应用

目的:建立基于克隆性分析技术的B和T淋巴细胞产生的抗原受体分子基因重排检测技术,探讨B淋巴细胞免疫球蛋白及T淋巴细胞受体基因重排在恶性淋巴瘤临床诊断中的应用.方法:从组织蜡块中切取组织片5～10张,提取基因组DNA,PCR扩增,聚丙烯酰胺凝胶电泳后银染显示基因重排结果.结果:20例良性淋巴组织反应性增生病例中,淋巴细胞IgH及TCR基因重排均为阴性;18例T细胞非何杰金氏淋巴瘤中TCRγ基因重排12例,TCRβ基因重排3例,未见有IgH基因重排;32例B细胞性非何杰金氏淋巴瘤标本中有28例IgH基因重排阳性,有2例TCRγ和IgH基因重排均阳性;3例未确诊的疑难病例均为IgH基因重排;IgH及TCR基因重排检出率在淋巴瘤组与良性组之间,差异有显著意义(P<0.05).结论:应用PCR法检测B淋巴细胞IgH和T淋巴细胞TCR基因重排可作为淋巴细胞来源的良、恶性病变的一种辅助诊断手段,且适用于石蜡标本以进行回顾性研究.

慢性非细菌性前列腺炎患者生殖支原体感染的检测及意义

目的:探讨生殖支原体(Mg)在慢性非细菌性前列腺炎发病中的作用。方法:采用培养法及聚合酶链反应(PCR)技术检测987例慢性非细菌性前列腺炎患者的前列腺液Mg,并与正常对照组125例进行比较。结果:①在987例慢性非细菌性前列腺患者的前列腺液标本中Mg阳性302例(31．5％),其中153例并发其他病原体感染,以并发解脲支原体(Uu)最多见(128例);②125例正常人前列腺液标本中Mg阳性3例 (2．53％),两组阳性率比较差异有显著性(X2=44．32,P<0．01)。结论:慢性非细菌性前列腺炎患者的Mg感染率高,Mg可能是慢性非细菌性前列腺炎发病的原因之一。

Pim-3异常表达在胃癌中的意义

目的:探讨Pim-3的异常表达在胃癌发展过程中的作用.方法:使用半定量RT-PCR法和免疫组化法检测40例胃癌组织及20例癌旁正常组织标本Pim-3的表达,并比较Pim-3的表达与胃癌临床病理参数的关系.结果:与正常胃黏膜相比,Pim-3mRNA的表达量在胃癌组织中更高(0.287±0.058 vs 0.053±0.055,P<0.001).中分化腺癌中Pim-3蛋白的表达高于低分化腺癌组织中的表达,两者比较差异显著(50%vs20%,P<0.05).Pim-3的表达与淋巴转移、静脉转移密切相关(r=0.385,0.412,P=0.014,0.008).结论:Pim-3可作为胃癌早期的生物标志物,并可预示肿瘤的预后.

PMA在RT-PCR检测药品细菌污染中的应用

建立有效区分死菌、活菌PCR检测方法,用于药品中细菌污染检测。选取金黄色葡萄球菌及大肠埃希菌,用叠氮溴化丙锭(PMA)前处理,使PMA与死菌DNA分子共价交联,抑制该DNA分子PCR扩增。当PMA浓度大于5μg·mL-1、曝光时间大于5 min时,PMA可抑制细胞膜破裂革兰氏阴性、阳性菌死菌DNAPCR扩增;PMA浓度大于20μg·mL-1时对活菌DNAPCR扩增产生一定影响。经过PMA前处理,能有效抑制死菌DNA扩增,在药品细菌污染PCR检测中有很好应用前景。