SERODIAGNOSIS OF CLONORCHIASIS BY ENZYME—LINKED IMMUNOSORBENT ASSAY WITH HRP—SPA

In thes paper the authors used the Horseradish peroxidase labelledstaphylococcal protein A(HRP—SPA)in ELISA,for the detection of Clo-norchis sinensis infection.Serum tests were made on 116 confirmed cases ofclonorchiasis,103(88.8%)of them showed positive,while only 6(4.4%)werepositive among 138 healthy people.Samples were collected on filter paperstrips,111(95.7%)cases were positive among 116 comfirmed cases tested,but only 2(1.5%)were positive out of 138 healthy persons.The resultswere similar to those obtained by sheep antihuman IgG.Animal experimentalso showed that the SPA—ELISA can be used for the diagnosis ofclonorchiasis.In an endemic area,stool egg positive rate was 8.8%(62/703).whenchecked with SPA—ELISA,the rate of conformity in both filter paperstrips and stool examinations was 90.3(56/62).Among 641 serum testsfrom individuals negative in stool examinations,only 35(5.5%)reactedpositively.The authors suggested—that SPA—ELISA with soluble Clo-norchis antigens could be used in a large scale seroepidemiological surveyin endemic areas.

Serological diagnosis of nasopharyngeal carcinoma by enzyme linked immunosorbant assay:optimization,standardization and diagnostic criteria

Objectives To produce an enzyme linked immunosorbant assay (ELISA) to detect antibodies against Epstein Barr virus (EBV) specified nuclear antigen 1 (EBNA 1) and the 18kD EBV matrix protein, and to determine and optimize its sensitivity and specificity for the diagnosis of nasopharyngeal carcinoma (NPC).Methods We used a combination of highly purified glutathione transferase fusion proteins of the 40kD carboxy domain of EBNA1 and the 18kD EBV matrix protein for coating ELISA plates. In three separate studies, we tested for IgA antibodies in serum specimens from 28 EBV seronegative donors, 284 EBV seropositive donors and 160 newly diagnosed NPC patients. By comparing the sensitivity and specificity of diagnosis obtained for different cutoff values, we derived several quantitative parameters to evaluate assay performance, establish objective diagnostic criteria which optimize the intrinsic diagnostic capability of the assay and assess the significance of individual test results, respectively. Optimum cutoff optical density (OD) is defined as the cutoff OD where sensitivity of the assay equals its specificity, and resolution of the assay is indicated by the value of sensitivity (or specificity) determined at the optimum cutoff OD. Diagnosis of NPC was achieved by setting a cutoff zone at +/-20% of this value.Results All the EBV seronegative donors tested were not reactive, and most of the EBV seropositive donors were weakly reactive, while the majority of NPC patients were moderately or strongly reactive. While the assay was thus shown to be specific for EBV, there was an overlap in the level of these serum antibodies between few individuals of the two latter groups. It was shown that the assay performed equally well in two separate studies conducted under different testing conditions and using different collections of sera in that assay resolution determined on these occasions were 86% and 87% respectively. Diagnosis of NPC can be achieved at the same expected sensitivity of 89% and 83% determined at the lower and upper limits of the cutoff zones, with the corresponding values of specificity being 78% and 91%. It was further shown in the third study that resolution of the assay can be increased to 90% using an assay produced with a higher concentration of the same antigens, and that diagnosis of NPC can be achieved at a higher sensitivity ranging between 86% and 95% at a corresponding specificity of 93% and 86%.Conclusions After optimization and standardization, the ELISA can achieve a sensitivity ranging from 86% to 95%, with corresponding specificities of 93% and 86% respectively for the diagnosis of NPC.

Concerns arise: wheat allergy risk in pre-packaged food products from China

Understanding and monitoring the cross-contamination of food allergens is crucial for safeguarding public health and ensuring food safety.Food allergen risk assessment,derived from classical toxicological principles,can identify and quantify the risk of allergies.This study aimed to investigate the risk of wheat allergic reactions to prepackaged foods from China through the utilization of food allergen risk assessment.A total of 575 products have been surveyed,wheat/gluten,milk and egg were major allergens labelled on products.According to voluntary incidental trace allergen labelling 3.0(VITAL®3.0)program,the number of products belonged to Action Level 2 were 303.Integration of precautionary allergen labeling(PAL)analysis indicated that 9.57%products would pose a potential risk to wheat allergic individuals.The probabilistic risk assessment results suggest that 7984 allergic reactions may arise among wheat-allergic consumers during 10000 eating occasions due to the consumption of pre-packaged food products with incorrect wheat-related allergen labelling.This study demonstrated that a risk assessment-based approach can support the guidance of allergen labelling and management of food allergen for pre-packaged food products,providing protection for allergic individuals in food consumption and for food manufacturers in food production and trade.

Development and evaluation of immunoassay for zeranol in bovine urine

A high affinity polyclonal antibody-based enzyme linked immunosorbent assay （ELISA） was developed for the quantification of zeranol in bovine urine. On the basis of urine matrix studies, the optimized dilution factors producing insignificant matrix interference were selected as 1：5 in pretreatment. In the improved ELISA, the linear response range was between 0.02 and 1 μg/ml, and the detection limit was 0.02 μg/ml for the assay. The overall recoveries and the coefficients of variation （CVs） were in the range of 82%-127% and 3.5%-8.8%, respectively. Thirty-six bovine urine samples spiked with zeranol （ranging from 0.2 to 10 μg/ml） were detected by the ELISA and liquid chromatography （LC） method, and good correlations were obtained between the two methods （R^2=0.9643）. We conclude that this improved ELISA is suitable tool for a mass zeranol screening and can be an altemative for the conventional LC method for zeranol in bovine urine.

新霉素ELISA检测方法的建立

目的:比较直接和间接竞争酶联免疫法(enzyme linked immunosorbent assay,ELISA)的优缺点,建立新霉素残留ELISA检测方法。方法:利用自制的新霉素多克隆抗体,采用直接竞争和间接竞争ELISA方法检测新霉素残留,并比较两种方法的优缺点。结果:新霉素抗血清和庆大霉素的交叉反应率为2.04%,和卡那霉素的交叉反应率为0.02%,和氨苄青霉素、红霉素、四环素的交叉反应率均小于0.01%。初步测试新霉素间接竞争ELISA法的准确性和回收率。板内误差小于4%,板间误差小于11%,回收率为135.5%～191.3%。直接竞争和间接竞争ELISA方法的检测极限分别为28.58ng/mL和51.74ng/mL,达到了国家对新霉素规定的500μg/kg MRL检测限。结论:建立了直接竞争和间接ELISA吸附检测方法,条件优化更成功的间接竞争ELISA可用于开发新霉素检测试剂盒。

重症大疱性类天疱疮患者血清抗体变化规律与病情相关性的研究

目的：研究重症大疱性类天疱疮（ bullous pemphigoid ， BP ）患者血清中抗体BP180NC16a的酶联免疫吸附试验（ELISA）指数变化情况，观察其与病情变化的相关性，并分析用于病情监测和指导治疗的临床意义。方法对12例皮损面积＞50％的重症大疱性类天疱疮患者血清抗体BP180 NC16 a水平在不同时期进行监测及评分，并分析之间的关系。结果12例患者，平均年龄65岁，皮损面积均大于全身体表面积的50％以上。皮疹主要表现为疱壁紧张的大疱、水疱，部分有口腔黏膜损害。患者皮损面积和病情评分与血清抗体BP180NC16a-ELISA指数具有显著性关联（P＜0．05），患者疾病活动期和临床缓解期抗体BP180NC16a-ELISA指数几乎与病情呈平行变化，并且该指数可以预测病情，从而指导治疗。结论重症大疱性类天疱疮多为老年患者，病情危重，在发病早期不易诊断，因而延误治疗导致死亡。血清中抗体BP180 NC16 a-ELISA 指数可反映疾病的活动程度，用于病情监测，为治疗时根据个体差异选用适量的糖皮质激素快速控制病情提供了有利的实验室证据。

A MONOCLONAL ANTIBODY RECOGNIZING NON DERIVATIVE 13 HYDROXY GIBBERELLINS AND THEIR GLUCOSIDES *

The production and characterization of a monoclonal antibody (MAb AB10) against GA 3 glucoside as well as GA 3 is described. MAb AB10 was derived from an immunogen in which human serum albumin (HSA) was linked to GA 3 at carbon 3. This antibody showed high affinity for GA 3 glucoside as well as for 13 hydroxy gibberellins (GA 1, GA 3, GA 5, etc). The affinity of MAb AB10 for 13 hydroxy GAs was significantly reduced by methylation of the 7 oic acid but not by glycosylation of 3 hydroxyl group. Based on this antibody, both of competitive enzyme linked immunosorbent assays (ELISAs) for GA 3 glucoside and for GA 3 were developed. These two ELISAs displayed linear detection ranges from 0 2 pmol to 20 pmol. Using these assays, the fluctuation of GA 3 like and GA 3 glucoside like substances in the leaves of Rumex japonicus was investigated. The results indicated that the glycosylation of free GAs was connected with leaf senescence and that the function of 6 benzyl amino purine in retarding the leaf senescence was probably related to delaying the process of glycosylation of free GAs.

Construction and Expression of Tp0453 Recombinant Protein of Treponema pallidum and Development of Indirect ELISA for Diagnosinq Syphilis

Objectives： To clone and express Tp0453 outer membrane protein of Treponema pallidum, and to evaluate its significance in the serodiagnosis of syphilis. Methods： The immuno-dominant epitope of Tp0453 gene was amplified from the complete genome of T.pallidum by polymerase chain reactions （PCR）, subcloned into the expression vector Pqe32 to generate recombinant plasmid Pqe32/Tp0453, and was then expressed in E. coli M15. The fusion protein was purified with Ni-NTA affinity purification. Indirect ELISA was developed to detect human serum IgG antibody to T. pallidum. Results： The recombinant Tp0453 protein was successfully expressed and purified. The recombinant protein had a molecular weight of approximately 32KDa.Indirect ELISA to the recombinant protein was developed.Sixty control sera were tested by ELISA and yielded a sensitivity of 100% （30/30） and a specificity of 100% （30/30）. While testing for T. pallidum in human sera, the sensitivity and specificity of ELISA were 96.8% and 100%, respectively, when compared with TPPA test results. The concordance of results between the ELISA test and the TPPA test was 98.2%. Conclusion： The recombinant Tp0453 outer membrane protein elicited a strong immunoreaction to anti-T.pallidum IgG antibody and has great potential use in ELISA for the serodiagnosis of syphilis.

三甲氧苄氨嘧啶单克隆抗体制备以及酶联免疫试剂盒的研究

[目的]探讨系统地检测水质中三甲氧苄氨嘧啶残留量的方法。[方法]通过三甲氧苄氨嘧啶与马来酸酐反应，得到三甲氧苄氨嘧啶半抗原，再通过免疫动物得到抗三甲氧苄氨嘧啶单克隆抗体，并将其应用于能够检测水质中三甲氧苄氨嘧啶残留量的ELISA试剂盒。[结果]试验表明，该试剂盒对水质中三甲氧苄氨嘧啶的检测限为2．34μg／kg，IC50（50％抑制浓度）为4．8μg／L，回收率为60．5％～79．7％，试剂盒的标准曲线范围为0～80μg／L，批内、批间的相对标准偏差均小于10％，三甲氧苄氨嘧啶单克隆抗体与二甲氧苄氨嘧啶的交叉反应率小于1％，4℃下能够保存12个月，稳定性较好。[结论]研究可为监管三甲氧苄氨嘧啶的滥用提供参考。

Preparation of Monoclonal Antibodies to Trimethoprim and ELISA Kit for Rapid Detection

[Objective] This study was conducted to find out an approach for determining trimethoprim residues in water. [Method] Trimethoprim antigen was prepared through a series of reactions from trimethoprim hapten which was generated through the reaction between trimethoprim and maleic anhydride. And trimethoprim monoclonal antibodies were prepared by animal immune, and used to prepare ELISA kit to detect trimethoprim residues in water. Finally, the limit of detection （LED） of the ELISA kit was determined. [Result] The standard curve covered a concentration range of 0-80 μg/L. The LeD of trimethoprim in water using the ELISA kit was 2.34 μg/kg; the IC50 （half maximal inhibitory concentration） was 4.8 μg/L; the recovery rate of added trimethoprim standard ranged from 60.5% to 79.7%; within-and among-batches RSD was less than 10%. The trimethoprim monoclonal antibody was specific, as the cross-reactivity rate of trimethoprim antibody and diaveridine was less than 1%. The stability tests revealed that the ELISA kit was stable after being stored at 4 ℃ for 12 months. [Conclusion] The results will provide references for controlling the abuse of trimethoprim.

单克隆抗体技术在小麦贮藏蛋白研究及其遗传改良中的应用进展

近20年来,人们制备了许多小麦种子贮藏蛋白的单克隆抗体(Monoclonal Antibody,McAb),一方面作为有效工具研究胚乳贮藏蛋白(主要是麦谷蛋白聚集体、特定的谷蛋白亚基及醇溶蛋白)的结构与功能关系;另一方面用作诊断试剂(diagnostic tools),为筛选具有合适加工品质的小麦品种提供依据。本文综述了国内外单克隆抗体技术在小麦贮藏蛋白研究及其遗传改良中的应用进展,并展望其应用前景。

Changes of p53 protein blood level in esophageal cancer patients and normal subjects from a high incidence area in Henan,China

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Serological prevalence and risk factor analysis of hepatitis G virus infection in Hubei Province of China

Hepatitis G virus (HGV),also known as GB virus C, is a recently cloned virus which may be associated with human non A-E hepatitis[1，2] It is parenterally transmitted and usually coinfected or superinfected with hepatitis B or hepatitis C virus[3-5]. Some investigations have been reported on the seroprevalence and molecular prevalence of HGV infection in different areas and different population[6-15]. Current infection of HGV is diagnosed by detection of HGV RNA, and past infection with HGV is detectable by testing anti-HGV envelope protein (E2)[16-17]. To investigate the prevalence of HGV in Hubei Province, a central area of the People's Republic of China, ELISA and RT-PCR were employed to detect serum anti-HGV and HGV RNA in 1516 patients who were divided into 16 groups.

Cloning and expression of NS3 cDNA fragment of HCV genome of Hebei isolate in E.coli

AIM To obtain greater antigenicity of HCV NS3 protein. METHODS The HCV NS3 cDNA fragment was amplified by reverse transcription polymerase chain reaction from the sera of the HCV infected patients. The DNA sequence was determined by dideoxy mediated chain termination method using T7 polymerase. HCV NS3 protein was expressed in E. coli . RESULTS Sequence analysis indicated that the HCV isolate of this study belongs to HCV Ⅱ; SDS PAGE demonstrated an M r 23800 and an M r 22000 recombinant protein band which amount to 14% and 11% of the total bacterial proteins separately. Western blotting and ELISA showed NS3 protein possessed greater antigenicity. CONCLUSION Recombinant HCV NS3 protein was expressed successfully, which provided the basis for developing HCV diagnostic reagents.

Potential of soluble CD26 as a serum marker for colorectal cancer detection

Colorectal cancer is characterized by a low survival rate even though the basis for colon cancer development,which involves the evolution of adenomas to carcinoma,is known.Moreover,the mortality rates continue to rise in economically transitioning countries although there is the opportunity to intervene in the natural history of the adenoma–cancer sequence through risk factors,screening,and treatment.Screening in particular accounted for most of the decline in colorectal cancer mortality achieved in the USA during the period 1975-2000.Patients show a better prognosis when the neoplasm is diagnosed early.Among the variety of screening strategies,the methods range from invasive and costly procedures such as colonoscopy to more low-cost and non-invasive tests such as the fecal occult blood test(guaiac and immunochemical).As a non-invasive biological serum marker would be of great benefit because of the performance of the test,several biomarkers,including cytologic assays,DNA and mRNA,and soluble proteins,have been studied.We found that the soluble CD26(sCD26)concentration is diminished in serum of colorectal cancer patients compared to healthy donors,suggesting the potential utility of a sCD26 immunochemical detection test for early diagnosis.sCD26 originates from plasma membrane CD26 lacking its transmembrane and cytoplasmic domains.Some 90%–95%of sCD26 has been associated with serum dipeptidyl peptidase IV(DPPIV)activity.DPP-IV,assigned to the CD26 cluster,is a pleiotropic enzyme expressed mainly on epithelial cells and lymphocytes.Our studies intended to validate this test for population screening to detect colorectal cancer and advanced adenomas are reviewed here.

A clinical evaluation of serological diagnosis for pancreatic cancer

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A clinical evaluation of serum concentrations of intercellular adhesion molecule-1 in patients with gastric cancer

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Association of Preoperative Serum IGF-Ⅰ Concentration with Clinicopathological Parameters in Patients with Non-Small Cell Lung Cancer

Insulin-like growth factor- I （IGF- I ） is a mitogenic and anti-apoptotic factor. Serum IGF-I concentration is related to some cancer risk and tumor progression. The aim of this research was to study the association of preoperative serum IGF- I concentration with clinicopathological parameters and prognosis of non-small cell lung cancer （NSCLC）. Preoperative serum IGF- I concentration was measured in 80 consecutive patients with NSCLC who underwent radical lung cancer resection, and 45 patients with benign pulmonary lesion （BPL） by Using enzyme linked immunosorbent assay （ELISA）. The results showed that the serum IGF- I concentration was elevated and correlated with clinicopa- thological parameters and overall survival （OS） in NSCLC patients. Serum IGF- I concentration was significantly higher in patients with NSCLC tfian in those with BPL. The IGF- I concentrations were significantly higher in NSCLC patients with 〉T2, NI-3, and in IIIA-IV but not in those with 〈T2, NO, or I A- IIB. The increased serum IGF- I concentration was significantly correlated with poor prog- nosis. Our data show the positive correlation between IGF-I serum concentration and the tumor size for the first time. It seems that IGF-I related to the progression of lung cancer may depend on autocrine/paracrine function. In addition, our study reveals that higher serum IGF- I concentration is correlated with larger tumor size, advanced stages, local lymph node metastasis and worse prognosis, indicating that endocrine IGF- I is also important for the progression for NSCLC.

DYNAMIC CHANGES OF SERUM VASCULAR ENDOTHELIAL GROWTH FACTOR LEVELS IN A RAT MYOCARDIAL INFARCTION MODEL

To investigate the dynamic changes of serum vascular endothelial growth factor(VEGF) levels in a rat model of acute myocardial infarction. Materials and methods.Eighty eight adult male Sprague Dawley rats weighing approximately 270 g were used in this study. Eighty rats were subjected to left coronary artery ligation, with 8 rats for each different duration of infarct. Eight sham operated animals in which the left coronary artery was surgically exposed without ligation were used as controls. Blood samples were drawn from the right atrium before (sham animals) and 1,3,6,12,24 h and 2,3,5,7,14 d after myocardial infarction. The concentrations of serum VEGF were measured by a sensitive enzyme linked immunosorbent assay with a rabbit polyclonal antibody specific for VEGF. Results. In the 8 control animals, the mean concentration of serum VEGF was 66.99±17.83 pg/ml. Six hours after myocardial infarction, the level of serum VEGF significantly increased to 125.68±28.07 pg/ml (P<0.01 vs. sham controls), and reached a peak (240.61±70.63 pg/ml. P<0.01 vs. sham animals) at 24 h after ligation and then decreased gradually over the remaining 2 weeks. However, the level remained significantly elevated for 14 d (107.64±30.13pg/ml, P<0.01 vs. sham controls). Conclusion. The present study shows that the levels of serum VEGF are markedly increased until 14 d in the rat model of acute myocardial infarction. The increased serum VEGF level may play an important role in the angiogenesis associated with myocardial infarction.

Levels of soluble delta-like ligand 1 in the serum and cerebrospinal fluid of tuberculous meningitis patients

In this study, the levels of soluble delta-like ligand 1 in cerebmspinal fluid and serum of 50 patients with tuberculous meningitis, 30 patients with viral meningitis, 20 patients with purulent meningitis and 40 subjects without central nervous system disease were determined using an enzyme-linked immunosorbent assay. The mean levels of soluble delta-like ligand 1 in both cerebrospinal fluid and serum from patients with tuberculous meningitis were significantly higher compared with those from patients with viral meningitis or purulent meningitis or from subjects without central nervous system disease. Meanwhile, the level of soluble delta-like ligand 1 gradually decreased as tuberculous meningitis patients recovered. If patients deteriorated after treatment, the level of soluble delta-like ligand 1 in cerebrospinal fluid gradually increased. There was no correlation between the level of soluble delta-like ligand 1 and the protein level/cell number in cerebrospinal fluid. Our findings indicate that the levels of soluble delta-like ligand 1 in cerebrospinal fluid and serum are reliable markers for the diagnosis of tuberculous meningitis and for monitoring treatment progress. At the same time, this index is not influenced by protein levels or cell numbers in cerebrospinal fluid.