A cyclic peptide–polymer probe for the detection of Clostridium botulinum neurotoxin serotype A

A Botulinum neurotoxin serotype A (BoNT/A) ELISA detection system was developed based upon an 11-mer cyclic peptide, termed C11-019, that was identified through peptide phage display technology. The assay employs a sandwich format using the C11-019 cyclic peptide attached to a PEMA (poly(ethylene maleic anhydride)) matrix as the capture phase and anti-BoNT/A polyclonal antibodies as the detection phase. Results reported demonstrate that the C11-019 peptide–polymer can specifically bind to BoNT/A with no cross-reactivity to other serotypes examined in assay buffers and a variety of body fluids and foodstuffs. When a highly sensitive chemiluminescent substrate was engaged, the detection of 1 pg/mL could be readily achieved within 3 h with a linear range of 0.1–1 ng/mL. These results demonstrate that an inexpensive peptide–polymer-based capture ELISA system can be used for rapid, sensitive and highly specific BoNT detection.     

Fumonisins as a possible contributory risk factor for primary liver cancer: A 3-year study of corn harvested in Haimen, China, by HPLC and ELISA

Employing HPLC fluorometry, gas-liquid chromatography (GLC) and a novel enzymelinked immunosorbent assay (ELISA) based on a monoclonal antibody, 40 corn samples, each collected in 1993 from agricultural stocks for human consumption in Haimen (Jiangsu County) and Penlai (Shandong Province), high- and low-risk areas for primary liver cancer (PLC) in China, respectively, were analysed for fumonisins (FBs), aflatoxins (AFs) and trichothecenes. Levels and positive rates of FBs and deoxynivalenol (DON) were significantly higher in Haimen than in Penlai. ELISA of the 40 corn samples harvested in the two areas in 1994 revealed that FB contamination levels and rates in these areas were comparable to those observed in 1993 in Haimen. ELISA analysis of 1993 and 1994 products revealed a wide occurrence of AFB₁ but the positive rates as well as levels were not significantly different between these areas. ELISA of the same sample number of corn harvested in 1995 revealed that FB contamination in Haimen was significantly higher than in Penlai. These 3-yearly surveys of corn samples (240 in total) demonstrated that corn harvested in Haimen was highly contaminated with FBs and that the contamination level, as well as positive rate in 1993 and 1995, were 10–50-fold higher than those in Penlai, suggesting FBs as a risk factor for promotion of PLC in endemic areas, along with the trichothecene DON. Co-contamination with AFs, potent hepatocarcinogens, was assumed to play an important role in the initiation of hepatocarcinogenesis.     

Quantification by ELISA of Aldrin/Dieldrin in river Nile water and tap water samples collected in Egypt

An indirect competitive ELISA was developed for the quantitative analysis of aldrin/dieldrin. This has been used to monitor the levels of these pesticides in water samples collected in Egypt. The detection range of the aldrin/dieldrin assay in water was 5–10 ppm without enhancement. River Nile water samples and tap water samples (n = 25) were collected from 25 stations in 16 different governorates in Egypt. Pesticides were detected in 10 of the 25 Nile water samples (40%) at levels from 10 to 110 ppb. In tap water samples, pesticides were not detected at levels greater than the lower limit of the assay. The technique described provides a rapid, economical, highly sensitive and specific method of analysis that is relatively simple to perform and interpret. It will be extremely useful in monitoring levels of pesticides in water used for human consumption.     

Stability studies of the components of a prototype penicillinase (β-lactamase)-linked ELISA kit

Penicillinase (β-lactamase) enzyme-linked immunosorbent assay (ELISA) for various reproductive hormones developed in the laboratory were found to have wide applicability in the fertility check clinic of the Institute. A need was thought to transform these assays into ready-to-use kit forms. Therefore, prototype ELISA kits for these hormones were developed and stability of the individual component was ascertained at various temperatures (room temperature, 37°C and 2-8°C). Stability studies were conducted on previously validated assay for pregnanediol-3α-glucuronide (PdG). The studies showed that immunosorbents (antibody coated plates) are stable at room temperature for a period of 2 weeks, at 37°C for 1 week and at 2-8°C for a period of 9 months when preserved after treatment with glycerol solution. The lyophilised conjugate, standard and immunoassay buffer, colour reagent, and its substrate were stable at 37°C up to 1 week and at room temperature up to 2 weeks and at 2-8°C for a period of 6 months, during which the stability was studied. © 1993 Wiley-Liss, Inc.     

EPF单克隆抗体杂交瘤细胞株的建立

本文用纯化的早孕因子免疫ＢＡＬＢ／Ｃ小鼠，通过鼠－鼠杂交瘤技术，成功地建立了２株分泌ＥＰＦ单克隆抗体的杂交瘤细胞。经检测，它们所分泌的抗体亚类均为ＩｇＧ１，毁交瘤染色体数目１００－１０６条，ＥＩＳＡ检测诱生腹水抗体效价为１：１．２８＊１０＾５，连续培养生物学性状稳定。抗ＥＰＦ抗原的单克隆抗体的建立，为深入研究ＥＰＦ的生物学性质、特征提供了有力的工具。     

重症肌无力病人乙酰胆碱受体抗体的测定及临床意义

用ＥＬＩＳＡ（固相酶联免疫吸附）法测定１７２例ＭＧ病人血清乙酰胆碱受体抗体（ＡｃｈＲａｂ），结果显著高于健康献血员组和非ＭＧ病人组。不同性别、病程及临床类型与ＡｃｈＲａｂ无相关性，但４１～５０岁组的显著高于其他年龄组。６７例类固醇激素治疗组、２２例大剂量两种球蛋白治疗组、１２例胸腺切除术组及３例ＭＧ危象病人２４次血浆交换疗法（ＰＥ）组，治疗后伴随肌无力症状的好转，ＡｃｈＲａｂ均显著低于治疗前。结果表明：ＡｃｈＲａｂ测定为ＭＧ诊断提供了可靠的实验依据，为类固醇激素、大剂量丙种球蛋白、胸腺切除术和ＰＥ等治疗ＭＧ提供理论依据和疗效评定的实验指标，进一步证实了ＭＧ免疫学发病机理。     

应用ELISA直接竞争法测定乳粉中黄曲霉毒素M_1

建立了测定黄曲霉毒素M_1的ELISA直接竞争法,其方法灵敏度为0.08ng/g。用该法测定了我国市售的乳粉97份,样品阳性率为84.5%,超标率(>0.5ng/g)为39.2%;阳性样品含量范围为0.08～4.16ng/g,调查结果证明我国南方生产的乳粉污染黄曲霉毒素M_1较严重。     

国产ELISA试剂盒应用于兴奋剂控制中的hCG检测

本文介绍用国产酶免定量药盒测定血、尿样中ｈＣＧ含量的一种ＥＬＩＳＡ方法。该方法特异性好、经济可靠而且简便快捷，适用于运动员尿样的兴奋剂检测。文中还报道了该方法应用于测定两例志愿者注射ｈＣＧ后的血、尿样及国际奥委会医学委员会１９９４年水平考试和１９９５年资格复试ｈＣＧ阳性尿样的结果，并讨论了测得值与其它试剂盒测定结果的差异及原因。     

组织型纤溶酶原激活物双单抗夹心ELISA建立及临床应用

本文动用自制ｔ－ＰＡ单克隆抗体建立ｔ－ＰＡ：Ａａ夹心ＥＬＩＳＡ法。结合ｔ－ＰＡ：Ａ、ＰＡＩ：Ａ测定，对５０例正常人，８７例肝病，４７例冠心病和１９例深静脉血栓 成患者的血浆ｔ－ＰＡ：Ａｇ、ｔ－ＰＡ：Ａ、ＰＡＩ：Ａ水平进行了研究。     

长沙市动物饲养员和屠宰工人等特殊人群弓形虫感染调查

目的 为了解长沙市动物饲养员、屠宰工人和宠物商贩等几种特殊人群弓形虫感染的情况。方法 采用ELISA法检测弓形虫抗体。结果 检测88名特殊人群，弓形虫IgG抗体阳性率为3．41％。结论 长沙市动物饲养员、屠宰工人和宠物商贩几种特殊人群弓形虫感染率低于全国平均水平，但仍有必要加强对动物密切接触者的健康教育，提高他们的自我防护意思。