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1.
目的:建立一种可快速、精确地对蓖麻毒素( RT)进行定量检测的上转发光免疫检测技术( UPT-LF),即RT-UPT-LF。方法采用杂交瘤细胞技术制备蓖麻毒素单克隆抗体并对效价进行评价;采用效价最高的4种单抗分别与上转发光纳米颗粒( UCP-NP)共价偶联,分别作为检测带,进而两两配伍,确定最优的配伍组合条件建立RT-UPT-LF方法;对RT-UPT-LF的敏感性、精密性、定量能力和特异性进行评价。结果与结论所建立的RT-UPT-LF方法可在15 min内完成对蓖麻毒素的检测,灵敏度可达0.5 ng/ml,定量范围为0.5~1000 ng/ml,与其他高浓度毒素无非特异反应,该法为蓖麻毒素检测提供了一种新手段。  相似文献   

2.
目的:研制针对4种常见食源性致病菌:甲型副伤寒沙门菌( Salmonella paratyphi A)、乙型副伤寒沙门菌(Salmonella paratyphi B)、大肠埃希菌O157∶H7(Escherichia coli O157∶H7)、副溶血弧菌(Vibrio parahaemolyticus)的基于上转发光免疫层析技术( UPT-LF)的快速定量检测试纸,并对其检测性能进行评价。方法以上转发光纳米颗粒( UCP-NPs)作为示踪物,基于双抗体夹心检测模型,研制针对上述4种靶标菌的UPT-LF试纸;以4种靶标菌的系列浓度标准菌悬液作为标准样品,评价试纸的敏感性、特异性、线性和精密性,并进行模拟染菌食品的检测,评价模拟样品阳性检出率。结果针对4种靶标菌的UPT-LF试纸均具有良好的线性,相关系数r为0.985~0.996;检测敏感性达105~106 CFU/ml,与其他近缘菌株无交叉反应;对乳制品、饮料、小食品、水产、肉类等细菌污染的食品检出率较高。结论该研究建立的对4种常见食源性致病菌进行快速检测的UPT-LF,简便快速,具有良好的敏感性、特异性和线性定量能力,操作性能可满足食品安全检测的要求。  相似文献   

3.
目的:建立能够同时检测沙门菌、副溶血弧菌(VPH)和单核细胞增生性李斯特菌(LM)的多重环介导等温扩增(mLAMP)方法。方法分别针对沙门菌 bcfD 基因、VPH 的 tlh 基因和 LM的 iap 基因设计 mLAMP 引物,以LAMP 进行单重 LAMP 检测。实时浊度监测扩增结果,优化引物浓度配比,进而建立此3种食源性致病菌的mLAMP 检测体系,以 PCR 检测灵敏性作为比较,进行特异性和灵敏性分析。结果实时浊度监测表明,该 mLAMP体系具有良好特异性,可在45 min 内一次性检测以上3种致病菌,且无非特异扩增产生。这3种菌的检测最低限分别为300 fg/μl、4.2 pg/μl 和4.5 pg/μl,与 PCR 检测灵敏度相当。结论该多重 LAMP 可同时检测食品中的沙门菌、VPH 和 LM,可作为大规模样品的初筛或传统方法的辅助方法,用于快速判定样品中是否含有这3种致病菌。  相似文献   

4.
目的:利用上转发光免疫层析技术( AFM1-UPT-LF)建立奶粉及牛奶中黄曲霉毒素M1的快速检测方法。方法以UCP颗粒作为标记物,无需样品前处理,采用竞争免疫反应建立AFM1-UPT-LF方法。以AFM1阴性的奶粉、牛奶配制系列浓度AFM1标准品,确定检测方法的灵敏度、特异性、标准曲线与定量范围、精密度、准确度及回收率,并对实际样品进行定性和定量检测评价。结果利用AFM1-UPT-LF可实现奶粉及牛奶中AFM1定性及定量检测,20 min内即可完成。奶粉中检测下限可达0.1μg/kg,在0.1~0.7μg/kg间具有较好线性(r=-0.99359, P<0.01),牛奶中检测限为0.3μg/L,在0.3~0.7μg/L间具有较好线性(r=-0.99938,P<0.05)。在定性检测中,对奶粉检测灵敏度为100%,特异性为85%,受试者工作特征(ROC)的曲线下面积(AUC)为0.978±0.036;牛奶检测中灵敏度为81%,特异性为88%, ROC的AUC为0.891±0.099;与LC-MS结果进行χ2检验,P值均大于0.05,两种方法差异无显著性意义。在定量检测评价中,AFM1-UPT-LF对于奶粉及牛奶中AFM1检测均具有较好回收率,与LC-MS比较差异无显著性意义(奶粉:t=0.66,P>0.05;牛奶:t=1.01,P>0.05)。结论利用UPT-LF所建立的AFM1-UPT-LF方法可实现奶粉及牛奶中AFM1定性及定量快速检测,检出限满足国标限量标准要求;该法无需样品处理,操作简便,可满足食品安全中对现场快速检测的需求。  相似文献   

5.
胶体金免疫层析技术快速定量检测相思子毒素   总被引:2,自引:0,他引:2  
目的:建立胶体金免疫层析技术快速定量检测相思子毒素。方法:利用胶体金标记和双抗体夹心免疫层析技术,建立相思子毒素的快速检测方法,评价其特异性和敏感性,并拟合检测曲线进行定量检测。在面粉、饼干、奶粉、苹果汁、牛奶、果冻等食品样品中添加相思子毒素模拟污染样品,评价该方法对固体、半固体、液体等食品样品的检测能力。结果与结论:该法可在15min内完成定性和半定量检测,灵敏度为30ng/ml,线性范围30~600ng/ml、回收率80%~110%,变异系数小于15%。所建立的检测相思子毒素的胶体金免疫层析方法,能快速、灵敏、特异、准确地检测样品中的相思子毒素,并可实现定量,适用于现场快速检测。  相似文献   

6.
多项肿瘤标志物联合检测对恶性胸腔积液诊断价值的探讨   总被引:1,自引:0,他引:1  
目的:探讨胸腔积液糖链抗原50(CA50),糖链抗原125(CA125)及癌胚抗原(CEA)3项指标联合检测对恶性胸腔积液的诊断价值。方法:CA50采用免疫放射技术测定,CA125与CEA应用全自动化学发光免疫分析技术检测。结果:恶性胸腔积液中CA50、CA125与CEA水平明显高于良性胸腔积液组,差异均有显著性(P〈0.01)。3项指标联合检测诊断恶性胸腔积液的敏感性71.8%,特异性90.0%,准确性80.6%。结论:胸腔积液CA50、CA125及CEA单项检测在恶性胸腔积液诊断中特异性较高,而敏感性均偏低,且三者联合检测可提高恶性胸腔积液的敏感性及特异性,临床诊断价值更大。  相似文献   

7.
目的:基于基因芯片技术建立一种能快速甄别粪肠球菌、屎肠球菌及万古霉素耐药基因的检测方法。方法根据GenBank中查找的2种常见肠球菌特异性基因序列( ddl)及万古霉素耐药基因( vanA,vanB)序列,设计与合成用于检测肠球菌的特异性基因及耐药基因的引物和探针,制备耐万古霉素肠球菌(VRE)检测基因芯片。利用多重不对称PCR法扩增样品中的特异性基因与耐药基因片段,标记产物与基因芯片上的探针杂交,经清洗、化学发光法显色后进行结果分析。在优化的多重PCR体系、杂交反应和化学发光法检测条件下,评价芯片的特异性、灵敏性和重复性。结果共筛选出1对通用引物、4对特异性引物和1条细菌通用探针、4条特异性检测探针。该芯片具有良好的特异性和重复性,灵敏性可达103 CFU/ml。10例临床分离株样本的芯片检测结果与药敏实验基本一致(8/10)。结论初步建立了检测VRE的基因芯片方法,利用此方法可以甄别2种VRE种类并检测其耐药基因。  相似文献   

8.
目的:建立斑点免疫金标渗滤法(DIGFA)检测棘球蚴囊肿抗体。方法:用金标探针检测血清抗体,并与ELISA法同步比较。结果:用DIGFA法检测已确诊棘球蚴肿病40例,抗体阳性38例,阳性率为90.4%,其它疾病94例,阳性6例,假阳性率6.2%,此方法的特异性和敏感性分别为90.4%和92.5%。与ELISA法相比无统计学差异(P>0.05)。但具有操作简便、快速、实用等特点。结论:DIGFA是诊断棘球缦囊肿病实用有效的血清学检测手段。  相似文献   

9.
酶联免疫试验法检测梅毒的体会   总被引:1,自引:1,他引:0  
微量絮状试验(VDRL),快速血浆反应素环状卡片试验(RPR),自动反应素试验(APT)等,对普及快速、准确诊断梅毒,虽有各自的优点,但总体而言这些试验的敏感性及特异性都较差,易出现漏检和误判。2003年3月-2006年11月,我院对327人份静脉血采用梅毒螺旋体酶联免疫试验法(TP-ELISA)检测,准确率可达90%以上。  相似文献   

10.
3种重要虫媒病毒的RT-PCR检测   总被引:2,自引:1,他引:1  
目的:建立快速、敏感、特异的虫媒病毒RT-PCR检测方法。方法:采用改进的核酸制备方法,分别从感染的乳鼠脑和细胞培养上清液中提取病毒RNA,再用RT-PCR和套式PCR方法进行检测。结果:通过对肌PCR反应条件的优化,用3种虫媒病毒的特异引物均可从不同稀释度的感染小鼠脑和细胞上清中提取的病毒RNA扩增出特异的目的基因片段。甲病毒属的东部马脑炎病毒和西部马脑炎病毒之间,及与黄病毒属的黄热病毒均无交叉反应,表明建立的RT-PCR检测方法特异性强。套式PCR与肝PCR比较可提高检测敏感性10~10000倍。结论:建立的肝PCR和套式:PCR法可用于3种虫媒病毒的快速检测。  相似文献   

11.
Digital radiography with large-area flat-panel detectors   总被引:3,自引:0,他引:3  
Kotter E  Langer M 《European radiology》2002,12(10):2562-2570
Large-area flat-panel detectors with active readout mechanisms have been on the market for the past 2 years. This article describes different detector technologies. An important distinction is made between detectors with direct and those with indirect conversion of X-rays into electrical charges. Detectors with indirect conversion are built with unstructured or structured scintillators, the latter resulting in less lateral diffusion of emitted light. Some important qualities of flat-panel detectors are discussed. The first phantom and clinical studies published report an image quality at least comparable to that of screen-film systems and a potential for dose reduction. The available studies are summarised in this article.  相似文献   

12.

Objective

The aim of this study was to determine (1) the effect of various scan delays on pixel intensity measurements and (2) the diagnostic accuracy of occlusal caries detection.

Methods

72 non-cavitated extracted human permanent molar teeth with sound and carious occlusal surfaces were radiographed using the DIGORA® storage phosphor plates (SPPs) (Soredex Corporation, Helsinki, Finland). Plates were scanned immediately and 10 min, 30 min, 60 min and 120 min after exposure. Three different plates were used for each scan delay. An aluminium (Al) wedge was used to evaluate the change in mean grey values (MGVs) for scan delays. Diagnostic accuracy for occlusal caries detection was performed by scoring all the digital images. The true presence of caries was determined by stereomicroscopy. Comparison of MGVs of the Al wedge for immediate and delayed scans was made using repeated measures analysis of variance (ANOVA) and Tukey–Kramer tests. The accuracy was expressed as the area under the receiver operating characteristics curves (Az). Azs were compared using two-way ANOVA and t-tests. Kappa was used to measure inter and intraobserver agreement.

Results

The mean Azs of immediately scanned plates were higher than the Azs of plates scanned with four different delays (p < 0.05). The Az of immediately scanned images was significantly higher than the Azs of images with 60 min and 120 min scan delays (p < 0.05) but not for 10 min and 30 min delays (p > 0.05). MGVs of immediately scanned plates were significantly higher than the plates scanned with four different delays (p < 0.05). Agreement decreased with increasing scan delays.

Conclusion

Scanning of DIGORA SPPs should not be delayed beyond 30 min for accurate occlusal caries diagnosis.  相似文献   

13.
Imaging plates (IPs) are a reusable media, which when exposed to ionizing radiation, store a latent image that can be read out with a red laser as photostimulated luminescence (PSL). They are widely used as a substitute for X-ray films for diagnostic studies. In diagnostic radiology this technology is known as computed radiography. In this work, the energy response of a commercial IP to beta-particle reference radiation fields used for calibrations at the National Institute of Standards and Technology was investigated. The absorbed dose in the active storage phosphor layer was calculated following the scaling procedure for depth dose for high Z materials with reference to water. It was found that the beta particles from Pm-147 and Kr-85 gave 68% and 24% higher PSL responses than that induced by Sr-90, respectively, which was caused by the different PSL detection efficiencies. In addition, normalized response curves of the IPs as a function of depth in polystyrene were measured and compared with the data measured using extrapolation chamber techniques. The difference between both sets of data resulted from the continuous energy change as the beta particle travels across the material, which leads to a different PSL response.  相似文献   

14.

Objective

The aim of this study was to determine the relationship between the amount of calcium loss, lesion depth, and the accuracy of storage phosphor plate (SPP) and film radiographs for the detection of artificial proximal demineralization.

Methods

Standard enamel windows of extracted premolars were exposed to a demineralizing solution for 60 h, 80 h, 100 h and 120 h. Solutions were analysed for calcium concentration by atomic absorption spectrometer and the lesion depths were calculated by a specific formula. All teeth were radiographed with SPPs and F-speed films before and after acid application. Images were evaluated by five observers. Stereomicroscopic and scanning electron microscopic (SEM) observations were carried out to visualize enamel surfaces after acid exposure. Receiver operating characteristic analysis was used for diagnostic accuracy (Az). Azs were compared with factorial analysis of variance and t-tests. The relationship between Azs and lesion depths was determined with Pearson''s correlation test.

Results

Strong positive correlation was found between Azs of both radiographic methods and lesion depths. No difference was found between the Azs of two radiographic systems for any of the demineralization durations (p > 0.05). Pair-wise comparisons revealed no significant difference in Azs of SPPs (p > 0.05), while significant differences were obtained for the Azs of films for different demineralization periods (p < 0.05). Stereomicroscopic and SEM observations confirmed demineralizations from superficial to deeper layers of enamel.

Conclusion

Subsurface enamel demineralization was not accurately detectable with either storage phosphor plates or F-speed films. The amount of calcium loss and the depth of demineralization have a strong relationship with diagnostic accuracy with a significant effect particularly on F-speed films.  相似文献   

15.
In order to evaluate the influence of radiation exposure on image quality in digital storage phosphor radiography, 200 digital storage phosphor chest radiographs, obtained on a neonatal Intensive Care Unit, and the same number of conventional screen-film radiographs (speed 250) were assessed for the visibility of anatomical structures and catheters. The same exposure parameters were used in both groups. Normal variations of radiation exposure under free exposure conditions were estimated in all digital images using a formula calculating radiation dose in the screen-plane from image sensitivity, latitude and average grey value of the right lung. There was already a significant (P < 0.001) decline in image quality in the digital images with a 30–50% reduction in radiation exposure, which was most severe for structures such as trachea, retrocardiac space, lung texture and low-contrast catheters. Compared with optimally exposed conventional images, only those digital images with a slightly higher than normal dose had an equivalent image quality. Correspondence to: U. Bick  相似文献   

16.
To determine the value of digital storage-phosphor radiography (SR) on the detection and identification of subtle lung nodules, postero-anterior (PA) and lateral (LAT) film-screen (FR) chest radiographs were compared with isodose SR images of 45 patients with metastatic malignancies. The SR postprocessing was done with a particular mode previously optimized for routine chest radiography. Pulmonary metastases were found in 34 patients and were proved or excluded by CT (n = 28) or longterm follow-up FR (n = 17). Chest images were divided into four regions for evaluation of image quality, number of lung nodules per region and marked pulmonary structures by receiver-operating characteristics (ROC) analysis (45 patients; 125 nodules; 2810 observations; five readers). Of the nodules selected for an ROC study 82 % were 0.5–1.0 cm in diameter. Overall image quality was rated better for FR concerning lung fields (PA) and mediastinum/hilum (LAT). More lung-field nodules were detected on FR than on SR chest images (P < 0.05). Use of FR was superior to SR in the general identification of nodules (PA chest), especially concerning intermediate (P < 0.01) and subtle abnormalities (P < 0.05), whereas there was no significant difference for LAT chest images. Our results show, that currently FR still has advantages over SR in the detection and identification of subtle lung nodules in routine clinical radiography. Correspondence to: R. Scheck  相似文献   

17.
电离辐射剂量监测用热释光探测器   总被引:5,自引:0,他引:5  
用固体能带(晶格能级)理论阐述了热释光探测用于剂理测量的机制;介绍了热释光探测器常用的5种磷光体,即LiF,CaSO4,CaF2,Li2B4O7和BeO的剂量学特性及其优缺点和使用中应注意的问题;给出了热压挤片法、热压切片法、冷压烧结法、毛细管封装法和树脂粘合法等热释光探测器的制备工艺,以及它们的适应范围。  相似文献   

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