荧光定量PCR法检测结核杆菌效果研究

目的:探讨荧光定量PCR法检测结核杆菌效果.方法:210例肺结核患者的血、尿、痰液标本均进行直接涂片和浓集涂片找抗酸杆菌和结核杆菌培养及FQ-PCR检测,观察3种方法检测不同标本中结核杆菌的阳性率.结果:本组痰标本中FQ-PCR技术检测结核杆菌阳性率为59.5%,高于涂片镜检的30.0%和结核杆菌培养的阳性率(39.1%),后两种与前者方法比较,差异有统计学意义(P<0.05).血和胸水标本中FQ-PCR技术检测结核杆菌阳性率分别为37.6%,36.7%,与其他两种方法比较差异均有统计学意义(P<0.05).结论:FQ-PCR应与常规细菌学方法互补使用,以提高结核病诊断的准确率.     

清幽健中汤联合西药治疗耐药幽门螺杆菌相关消化性溃疡的临床观察

目的:观察清幽健中汤联合四联补救疗法治疗耐药幽门螺杆菌相关消化性溃疡的疗效.方法:将92例耐药幽门螺杆菌相关消化性溃疡患者,随机分成两组.对照组45例使用四联补救疗法,然后再服用奥美拉唑20mg,每天2次,连服4周进行治疗;治疗组47例服用清幽健中汤联合四联补救疗法治疗.结果:治疗组总有效率明显高于对照组;胃镜下溃疡愈合率明显高于对照组;幽门螺杆菌根除率明显高于对照组;不良反应总发生率明显低于对照组.结论:清幽健中汤联合四联补救疗法治疗耐药幽门螺杆菌相关消化性溃疡,治疗耐药幽门螺杆菌相关消化性溃疡有明显优势.     

荧光定量PCR检测单核细胞增生性李斯特氏菌

[目的]建立一种快速检测单核细胞增生性李斯特氏菌的实时荧光定量PER方法.[方法]针对单核细胞增生性李斯特氏菌的特异基因hlyA,结合锁定寡核苷酸(LNA),设计引物和探针,利用阳性质粒和模拟标本建立单核细胞增生性李斯特氏菌实时定量荧光PCR检测方法.[结果]以单核细胞增生性李斯特氏菌为模板克隆了hlyA基因,得到阳性质粒,并进一步建立了荧光定量PCR方法,得到标准曲线Y=-3.273 X+37.640,相关系数R<'2>=1.000;该方法的灵敏度可以达到1.2×10 CFU/ml;人工污染猪肉检出限可以达到3.2×10<'2>CFU/ml.[结论]建立了快速检测单核细胞增生性李斯特氏菌的实时荧光定量PCR方法,为实现食品中单核细胞增生性李斯特氏菌的快速检测构建了一个技术平台.     

新疆阿拉尔垦区猪嗜血支原体PCR检测方法的建立

[目的]掌握阿拉尔垦区猪嗜血支原体的流行现状.[方法]根据GenBank上发表的猪嗜血支原体16S rRNA基因组序列(U88565)设计1对特异性引物,对采自新疆阿拉尔垦区的样品进行PCR扩增,并将其产物克隆到pBR322载体后测序.[结果]扩增出的片段为0.836 kb.同源性分析结果表明,该序列与猪嗜血支原体参考基因组序列同源性为99.47%,反映出我国分离株与国外株基因同源性较高.[结论]建立了一种猪嗜血支原体PCR检测方法,该方法为猪嗜血支原体病的快速诊断及流行病学调查提供了新的手段,并为相关基因的表达及功能研究奠定了基础.     

实时定量PCR检测大鼠神经激肽1受体mRNA方法的建立及评价

目的:建立检测大鼠神经激肽1(NK1)受体mRNA的SYBR Green Ⅰ实时定量PCR方法,为检测大鼠NK1受体基因表达提供有效的手段.方法:提取大鼠中脑总RNA,扩增NK1受体基因片段,将其克隆入pMD-18T载体,制作NK1受体标准品质粒;应用SYBR Green Ⅰ双链嵌合染料,对连续稀释的标准品质粒进行实时PCR分析,评价所建立方法的检测灵敏度;对PCR产物进行溶解曲线分析评价其特异性.结果:成功构建NK1受体标准品质粒,经酶切及测序鉴定,目的片段已插入pMD-18T载体;所建立的实时定量PCR方法的最低检测限度均为每反应102个拷贝,在每反应102～109拷贝范围内,荧光信号达到设定阈值所经历的循环数(Ct值)与起始模板浓度具有良好的线性关系,r=0.999.结论:所建立的检测大鼠NK1受体mRNA的SYBR Green Ⅰ实时定量PCR方法具有敏感性高、特异性强和线性范围广等特点,适用于对大鼠各种组织NK1受体的大量样本检测.     

记忆合金材料的X荧光快速分析方法的建立

介绍了抚钢使用本厂光谱套标和厂控标样在X荧光光谱仪上建立了记快合金材料的分析立法 ,为国内同行业用X荧光光谱仪分析检验记忆合金材料起到借鉴作用。     

食品中沙门氏菌的不同检测方法分析

目的:讨论沙门氏菌引起食物中毒对公共安全的危害,综合分析目前对食品检验中针对沙门氏菌的检测方法.方法:通过对目前食品中针对沙门氏菌的不同检测方法进行分析.结果:目前常用的检测方法,通过人们不断地努力,已经非常完善.结论:食品安全事关人们群众的身体健康,我们需要不断探索,研究出更加早期、准确、方便、适宜推广的检测方法.     

荧光定量PCR技术在植物病原检测方面的应用

就实时荧光定量PCR的原理、应用和不足及前景等方面进行了论述.实时荧光定量PCR技术以其快速、灵敏、准确和高通量等特点受到了人们越来越多的重视,被广泛的应用于生物学研究的各个领域.近年来在植物病原检测方面,已建立了一大批植物病原的实时荧光定量PCR方法,这为植物病害的准确诊断与防控提供了强有力的工具.     

Taqman定量PCR技术检测转基因大豆中外源基因拷贝数

[目的[采用Taqman定量PCR技术检测转基因杂交大豆中外源nos终止子基因的拷贝数.[方法]以大豆凝集素基因为内参照基因,以非转基因大豆基因组DNA为内参照基因标准品,通过梯度稀释法分别求取了内参照基因和质粒DNA的Ct值与拷贝数对数值的相关性标准曲线方程,并通过将得到的Ct值代入标准曲线方程求取了样品的拷贝数.[结果]内参照基因标准曲线方程为y=-3.422x+35.201,R2=0.998;外源基因标准曲线方程为y=-3.348x+34.890,R2=0.999.nos终止子基因及其下游边界序列在转基因杂交大豆中为单拷贝.[结论]为确定转基因大豆外源基因拷贝数提供了理论依据.     

能量色散X射线荧光光谱法对水溶液中多种重金属离子的检测方法探讨

使用小台式的能量色散X射线荧光光谱仪可以实现水溶液中多种痕量重金属离子的直接测试,不需要对溶液进行消解,且仪器简单,对环境要求低.通过对谱线能量不同的元素进行分组,对各组元素的滤光片进行选择:对于铬、锰、铁,使用0.2 mm Al滤光片;对于镍、铜、锌、铅、硒、砷、汞,使用0.5 mm Ti滤光片;对于锑,使用1.25...     

Comparison of five PCR methods for detection of Helicobacter pylori DNA in gastric tissues

Five different PCR methods for the detection of Helicobacter pylori were evaluated. The results of this study indicate that of the five PCR methods examined, the ureC (glmM) gene PCR is the most sensitive and specific for the detection of H. pylori in gastric biopsy specimens.     

Comparison of diagnostic methods for detection of Helicobacter pylori

Of two hundred Ethiopian patients with dyspepsia, multiple biopsies were taken from the antrum of the stomach. Helicobacter pylori was cultured from 85% of duodenal ulcer and in 75% of chronic antral gastritis patients. The overall Helicobacter pylori positivity was 70%. The sensitivity, specificity, positive and negative predictive values of the tests as compared to culture were as follows, respectively: direct urease test 100%/87%/95%/100%, direct gram stain 60%/98%/99%/51%, histological gram stain 66%/97%/98%/56%, Giemsa stain 100%/97%/99%/100% and Gimenez stain 100%/87%/95%/100%. It is concluded that gram staining of direct tissue smear or histology is an insensitive method in the diagnosis of Helicobacter pylori. All the other tests, are shown to be valid. Urease test is an excellent test for provision of presumptive diagnosis of Helicobacter pylori while awaiting confirmation either by culture of histology.     

Helicobacter pylori and functional dyspepsia: a real causal link?

This chapter reviews the evidence for a link between functional dyspepsia and Helicobacter pylori infection from three angles. In the section on pathophysiology, we evaluate how H. pylori could theoretically produce dyspeptic symptoms: many mechanisms can be proposed. In the discussion on epidemiology, we evaluate possible associations between the occurrence of symptoms and infection. Here, many studies claiming a coincidence or chronological sequence of infection and symptoms are criticized because of their poor design. In the section on the improvement of functional dyspepsia by the treatment of H. pylori infection, the conclusion is reached that if such an effect occurs at all--which is unlikely--it is very weak. The controversy on the link between H. pylori infection and functional dyspepsia is presently ongoing. Some authors are still trying to save an elegant concept that once looked so plausible but now has the facts against it.     

Positive association between Helicobacter pylori infection and food allergy in children

BACKGROUND: In children Helicobacter pylori has been involved as a pathogenetic factor in gastritis and duodenal ulcer and as a cofactor in protein-losing enteropathy, chronic diarrhoea, short stature, and gastritis lymphoproliferative disease. A subset of an H. pylori strain possesses an antigen, CagA, as a virulence factor. In the present study we determined anti-H. pylori IgG and anti-CagA IgG titres in children with food allergy. METHODS: Ninety paediatric patients were studied: 30 with food allergy, 30 with atopic asthma, and 30 with inflammatory bowel disease. Anti-H. pylori IgG and anti-CagA IgG were determined in all children by means of a commercial enzyme immunoassay (ELISA). RESULTS: The anti-H. pylori IgG titre was significantly higher in allergic patients than in the other two groups. The anti-CagA IgG titre did not differ significantly between the patients. CONCLUSIONS: These findings show a positive association between H. pylori infection and food allergy in children. We hypothesize that virulence factors other than CagA may be involved in the pathogenesis of H. pylori infection in paediatric patients with food allergy.     

Evaluation of eight commercial kits for Helicobacter pylori IgG antibody detection

Eight commercial kits and an in-house ELISA for detection of IgG antibodies against Helicobacter pylori were evaluated for their use in diagnosis of H. pylori infection and in epidemiological research: Helico-GTM (Porton-Cambridge), G. A. P. test (Bio-Rad), H. pylori antibodies ELISA (Biometra), Anti-H. pylori IgG EIA (Roche), 2nd generation H. pylori EIA (Roche), Anti-H. pylori MTP-assay (Roche), Pylori stat test kit (Whittaker), Pyloriset latex agglutination kit (Orion), and the in-house ELISA based on heat-stable antigens. Fifty-four patients with dyspepsia (31 H. pylori positive by culture or microscopy) and 68 asymptomatic persons were tested. Sensitivities for the eight kits were 71%, 77%, 90%, 84%, 87%, 94%, 90%, 87%, and 87%, specificities were 74%, 65%, 74%, 74%, 83%, 83%, 70%, 65%, and 65%, respectively. For epidemiological use the estimated seroprevalence varied within approximately 15% in all age groups. Sensitivities and specificities obtained in different studies reveal as great differences in the results with the same kit as between results obtained with different kits in the same study. Kits with the highest sensitivities tend to be the same in all studies. It is therefore more important to test a kit in the population to which it is to be applied than to choose a specific kit.     

An evaluation of whole blood testing for Helicobacter pylori in general practice

BACKGROUND: Rapid whole blood tests for Helicobacter pylori infection were developed to assist in the management of patients with dyspepsia in general practice. However, they have not been extensively tested in this setting. AIM: To investigate the test characteristics of the BM-Test (Helisal Quick Test) when used in general practice. METHOD: One hundred and ten dyspeptic patients attending local general practitioners were recruited into the study. The BM-Test was administered by the general practitioner at the screening visit according to standard instructions supplied with the test kit. The patient was then referred to Nepean or Mornington Peninsula Hospitals for further assessment. including a 14C-urea breath test. The test kit was forwarded to the appropriate hospital centre for an independent, blinded reading. The sensitivity and specificity of the BM-Test were evaluated against the results of the 14C-UBT. RESULTS: Based on general practitioner readings, the BM-Test had a sensitivity of 59.3% and a specificity of 90.2%. The positive and negative predictive values were 87.5% and 65.7%, respectively. When based on independent readings, sensitivity rose to 71.2% and specificity fell to 88.2%. The BM-Test was more sensitive for older patients than for younger patients when based on both the general practitioner and independent readings. CONCLUSION: The BM-Test performs below the generally recommended sensitivity and specificity of 90% required for clinical practice.     

Detection of Helicobacter pylori in stool specimens by PCR and antigen enzyme immunoassay

A highly sensitive seminested PCR assay to detect Helicobacter pylori DNA in feces was developed. PCR with stool specimens and a novel antigen enzyme immunoassay (EIA) for H. pylori detection in feces were evaluated as diagnostic tools and in follow-up with samples from 63 infected and 37 noninfected persons. Infected individuals received eradication therapy followed by endoscopic follow-up 35 days after the start of treatment. At that time, a second stool specimen was obtained from 55 of these patients. Before eradication, the sensitivity of PCR was 93.7% and that of EIA 88.9%. Specificities were 100 and 94.6%, respectively. Of the 55 follow-up specimens, 41 originated from patients from whom H. pylori had been eradicated. Of these, 21 were still positive by PCR and 13 were positive by EIA, indicating that 1 month may be too short a period for follow-up evaluation of stool specimens by these tests.     

Comparison of two rapid urease tests for detection of Helicobacter pylori infection

The selection of NIH 3T3 cells expressing a hydroxytamoxifen-inducible c-Raf-1-estrogen receptor fusion protein (c-Raf-1-BxB-ER) in the absence or presence of the inducer results in dramatic differences in the expression levels of the fusion protein. Hydroxytamoxifen-mediated constitutive activation of the Raf signal favors the selection of cells expressing low levels of c-Raf-1-BxB-ER. Cells selected in the absence of hydroxytamoxifen express up to 20 times higher levels of the inducible Raf kinase. Activation of the oncogenic Raf kinase in cells expressing low levels leads to a weak activation of the Raf/Mek/Erk cascade and the induction of S phase in confluent cells. The activation of cells expressing high levels of the kinase leads to a strong persistent signal and inhibits DNA synthesis and mitosis in proliferating cells. The inhibition of DNA synthesis and cell division is presumably due to the elevated expression of the cyclin-dependent kinase inhibitor p21cip1, similar to cells exposed to ionizing radiation. Despite the inhibition of DNA synthesis and mitosis, the constitutive activity of the Raf signaling pathway is still able to initiate cell growth. Activation of the high-intensity Raf signal in arrested serum-starved cells induces cell growth up to a size corresponding to that of M-phase cells in the absence of DNA synthesis. High-intensity Raf signals in proliferating cells consistently lead to an accumulation of cells with the size of M-phase cells and the DNA content of G1 cells or G2-M-phase cells. Therefore, the activation of Raf kinase is sufficient to drive cell growth, even in the presence of high levels of the cyclin-dependent kinase inhibitor p21cip1.     

Methodological study of 13C-urea breath test for detection of Helicobacter pylori infection

In this study, we investigate simple breath test for detection of Helicobacter pylori (HP) infection using 13C-urea. Thirty-nine patients (30 were HP positive, 9 were HP negative) were given three different doses (50, 100 and 150 mg) of 13C-urea at fasting, and keep sitting after mouth washing with water. Breath samples were taken before and 10, 20, 30, 45, and 60 minutes after urea administration. More than 100mg of 13C-urea was necessary for correct diagnosis of HP infection, because 2 HP positive cases were not detected by 50mg 13C-urea administration. In cases with patchy distribution of HP in the stomach, it may be necessary to change the posture to distribute urea within the whole stomach. In most of HP positive cases, peak delta 13CO2 were obtained within 30 minutes, but one HP negative case showed high delta 13CO2 at 10 minutes, which was probably caused by urease activity in the mouth. So it is appropriate to take breath sample at 20 minutes after urea administration. In this study, cut-off value for a positive test can be setted between 4 to 7 delta/1000, it is necessary to investigate much more cases to set exact cut-off value.