化学发光酶联免疫分析法同时检测3种有机磷农药残留

利用能同时识别对硫磷、甲基对硫磷和杀螟硫磷的宽谱特异性单克隆抗体,建立了同时测定这3种有机磷农药残留的化学发光酶联免疫分析方法（chemiluminescence enzyme immunoassay,CLEIA）,比较了间接竞争（ic-CLEIA）和直接竞争（dc-CLEIA）2种反应模式,优化了相关理化参数,确立了最适反应条件。结果表明:间接竞争CLEIA法检测对硫磷、甲基对硫磷和杀螟硫磷的抑制中浓度（IC₅₀）分别为5.57、2.30和2.62 μg/kg,检测线性范围分别为0.39~100、0.39~25和0.39~25 μg/kg;直接竞争CLEIA法检测对硫磷、甲基对硫磷和杀螟硫磷的抑制中浓度（IC₅₀）分别为5.43、1.34和1.24 μg/kg,检测线性范围分别为0.39~100、0.10~25和0.10~25 μg/kg。所建立的CLEIA方法基本能满足对硫磷、甲基对硫磷和杀螟硫磷在谷物和果蔬中最大残留限量的检测要求,为研制有机磷农药多残留检测试剂盒提供了技术依据。     

3种血清肿瘤标志物在诊断大肠癌中的价值

目的：探讨癌胚抗原（CEA）、糖链抗原（CA199．casbohydrate antigen19-9）和CA242（casbohydrate antigen 242）在大肠癌的临床价值。方法：采用微粒酶免疫法（MEIA）检测30例大肠良性疾病及45倒大肠癌患者血清CEA,CA199和CA242的水平。结果：大肠癌患者与大肠良性疾病患者的CEA,CA199和CA242水平比较差异有显著性（P〈0．01～0．05）。血清CEA,CA199和CA242的水平随大肠癌病程的进展而逐渐升高;3种肿瘤标志物中以CA242敏感性和特异性最高．分别为60．3％和73．3％．3种肿瘤标志物对诊断的敏感性与大肠癌的分期有关;联合检测可使诊断的敏感性提高至83．6％。结论：血清CEA,CA199和CA242水平测定可应用于大肠癌的诊断和疗效的观察,并可用于监测肿瘤的复发和转移。肿瘤标志物的联合检测有助于大肠癌的早期诊断,并增加诊断的敏感性和特异性。     

IgY在免疫检测及治疗中的应用进展

卵黄抗体(IgY)是存在于卵黄中的免疫球蛋白,是鸟类、爬行动物和两栖类动物体内的主要抗体,具有强大的免疫功能。论文介绍了卵黄抗体的分子结构和理化特性,综述了IgY在寄生虫(弓形虫、血吸虫、球虫)、细菌(肠产毒素大肠埃希菌)、病毒(B型流感病毒、狂犬病病毒)等病原检测、抗生素(卡那霉素、庆大霉素)残留检测及相关疾病如雏鸡球虫病、猪大肠杆菌病、鳗鱼弧菌和利斯顿氏菌病、轮状病毒病治疗中的应用,并指出目前IgY应用中存在的诸如可能存在禽类未知病原、尚无生产标准规程以及稳定性不够理想等问题。因卵黄抗体具有安全、高效、无公害的特点,其在疫病检测和防治中具有广阔的应用前景。     

Endotoxin and Arachidonic Acid Metabolites in Portal,Hepatic and Arterial Blood of Cattle with Acute Ruminai Acidosis

Andersen, P. Haubro, M. Hesselholt and N. Jarlev: Endotoxin and arachidonic acid metabolites in portal, hepatic and arterial blood of cattle with acute ruminai acidosis. Acta vet.scand.1994,35,223-234.– Ruminai acidosis was induced experimentally with 70 g barley / kg body weight in 2 rumen fistulated cows with chronic indwelling catheters in the portal vein, in a hepatic vein and the carotid artery. The cows were followed for 24 and 20h after the overfeeding and evaluated clinically and by clinical chemistry. The 2 cows exerted different responses to the treatment. Both cows showed signs of severe ruminai acidosis. Both cows had endotoxin in portal and hepatic vein blood, but only 1 of the cows convincingly developed a systemic endotoxaemia. A pre-hepatic release of the stable prostacyclin and thromboxane metabolites, 6-ketoprostaglandin F_lα and thromboxane B₂ was demonstrated in this cow. The results of the present study show that endotoxin and arachidonic acid metabolites of pre-hepatic origin may be factors involved in the pathogenesis of ruminai acidosis, and that investigation of the factors affecting translocation of ruminai endotoxin and subsequent clearing in the liver, will be of importance.     

A Labelled Avidin–Biotin ELISA to Detect Antibodies to Caprine Arthritis-encephalitis Virus in Goats' Sera

A labelled avidin–biotin ELISA (lab-ELISA) was developed and compared with indirect ELISA (i-ELISA) and agar-gel immunodiffusion assay (AGID) for its efficacy in detecting antibodies against caprine arthritis-encephalitis virus (CAEV) in goat sera. The enzyme immunoassays were standardized using 113 sera from CAEV-negative goat flocks. The tests were compared using the results from 339 serum samples. The lab-ELISA showed the greatest number of positive results (94/339) as compared with AGID (51) and i-ELISA (64). The comparison of the other two tests with the lab-ELISA showed an agreement of 87.3% with AGID and 90.6% with i-ELISA. The lab-ELISA may be useful for screening large populations for CAEV antibodies, in epidemiological surveys and in the control of caprine arthritis-encephalitis.     

Concentrations of C-reactive Protein in Normal Monkeys (Macaca irus) and in Monkeys Inoculated with Bordetella bronchiseptica R-5 and Measles Virus

The concentrations of C-reactive protein (CRP) in serum from normal crab-eating monkeys (Macaca irus) were measured by means of a monkey-specific turbidimetric immunoassay (TIA), and the changes in the serum CRP concentrations in crab-eating monkeys inoculated with Bordetella bronchiseptica R-5 and measles virus (Ichinose or NK 3 strain) were also examined. The CRP concentrations in sera from 54 normal crab-eating monkeys ranged from 0 to 8.3 g/ml (mean 2.2±1.9). No significant difference was found in the CRP concentrations between males and females (p>0.05). The concentrations of CRP in the sera from four crab-eating monkeys inoculated intrabronchially with 10⁹ live B. bronchiseptica increased gradually to a peak at 2 days after inoculation. The peak concentrations of CRP were from 102.4 to 313.2 g/ml, 54–96 times the preinoculative values of 1.9–5.6 g/ml. When the same four crab-eating monkeys were inoculated intrabronchially with measles virus 34 days after inoculation of B. bronchiseptica, the serum CRP concentrations did not increase. Monitoring of CRP is useful for assessing monkeys with acute B. bronchiseptica infection and will probably be of value in the diagnosis of other bacterial infections.     

电化学酶联免疫分析检测烟草花叶病毒和烟草环斑病毒

以邻苯二胺 (OPD)底物为例 ,用抗原直接包被法 (DAC -ELISA)同线性扫描极谱法 (LSV)相结合 ,检测烟草花叶病毒 (TMV)的提纯液 ,检出限可达 0 2 5ng/ml,TMV粗提液的最高稀释比为 1 :1 0 2 4 0 0 ;检测烟草环斑病毒 (TRSV)提纯液 ,检出限为 1 0ng/ml,粗提液的最高稀释比为 1 :1 0 0 0 0 ,该方法的灵敏度比DAC -ELISA光度法提高了 5倍以上     

A Preliminary Comparative Study of a Dipstick Colloidal Dye Immunoassay and Two Antigen-detection ELISAs for Diagnosis of Trypanosoma evansi Infection in Cattle

A dipstick colloidal dye immunoassay (DIA) was developed for the field diagnosis of Trypanosoma evansi infection using affinity-purified polyclonal antibodies (PcAbs) and the monoclonal antibody (McAb) 8B9. PcAbs were adsorbed onto Palanil Red dye particles and used as dye reagents. Dipsticks were dotted with four different antibodies; normal rabbit and mouse IgGs as negative controls, and anti-T. evansi PcAb and McAb 8B9, which capture trypanosome antigens in the tested samples. Since the dye reagent bound to the captured antigens, the presence of coloured dots on the dipstick identified trypanosome infections. The sensitivity of the DIA was compared with two antigen detection ELISAs (Ag-ELISA); one was PcAb-based and the other was based on a combination of the same Mc- and PcAbs as were employed for the DIA. With a positive serum, the DIA detected trypanosomal antigen up to a dilution of 1:500 for both the PcAb and McAb dots, at which dilution the PcAb- and combination-based Ag-ELISA gave positive OD readings of 0.13 and 0.36, respectively. When 124 field sera were tested, circulating antigens were detected in 51 (41%) samples by the DIA, and 76 (61%) and 49 (40%) samples by the PcAb- and combination-based Ag-ELISAs respectively, of which 48 (63%) and 34 (69%) were also positive by the DIA.     

奶牛乳汁孕酮免疫检测方法研究进展

有关乳汁孕酮的放射免疫检测技术和酶联免疫检测技术，近几十年来不断有报道，并逐渐成熟。但是测试费用、技术人员培养及方法本身的弊端等因素，使得这些项技术的普及受到了限制。这就要求从业人员不断创新，开发更有市场价值、老百姓更易接受的测试方法。胶体金试纸条在医学上应用广泛，已经呈现出了它应用于动物医学中，在激素测定方面乐观的应用前景。     

The use of divalent cation chelating agents (EDTA/EGTA) to reduce non-specific serum protein interaction in enzyme immunoassay

An indirect enzyme immunoassay (ELISA) for detection of bovine antibody toBrucella abortus was modified by the addition of divalent chelating agents to the serum diluent. This addition resulted in an increase in specificity from 96.0% in the regular assay to 99.4% in the modified procedure. Of the 15 715 sera initially tested by the indirect ELISA, 691 that had given positive reactions were selected for retesting in the indirect ELISA with EDTA/EGTA added. The buffered plate antigen test (BPAT) correctly identified 98.6% of the samples as negative. The addition of chelating agents did not alter the sensitivity of the indirect ELISA, which correctly classified 609 sera from animals from whichB. abortus had been isolated as positive. The sensitivity of the BPAT was 97.8%.Abbreviations ABTS 2,2-azinobis(3-ethylbenzthiazoline sulphonic acid) - BPAT buffered plate antigen test - EDTA ethylenediaminetetraacetic acid disodium salt - EGTA ethylene glycol-bis(-aminoethyl ether)-N,N,N,N-tetraacetic acid - ELISA enzyme-linked immunosorbent assay - IgG₁ immuno- globulin G₁ - IgM immunoglobulin M - Tris tris(hydroxymethyl)aminomethane