湖羊口蹄疫不同免疫剂量及3种苗联免抗体效价对比试验

湖羊口蹄疫的传播和蔓延不仅会危害一个地区羊养殖产业的安全,而且会威胁人类身体健康。口蹄疫是我国强制免疫的病种之一。通过对湖羊养殖场应用囗蹄疫O型灭活苗进行不同剂量、加免及口蹄疫、小反刍、羊传染性胸膜肺炎3种疫苗分点联免效果进行对比分析,对比试验表明口蹄疫疫苗标准剂量加强注射确实能提高抗体水平,而且抗体产生的快,保护期长。

抗强毒新城疫、禽流感(H5、H9)多价二联高免卵黄抗体的研制和应用

以强毒新城疫 (VND)、禽流感 (AIH5、H9型 )高效价抗原多次免疫健康蛋鸡 ,收集ND、AI卵黄抗体均高于14Log2的鸡蛋 ,经过特殊工艺处理 ,加入一定量的丁胺卡那霉素、防腐剂按适当比例用灭菌生理盐水稀释制备新城疫、禽流感 (H5、H9)多价二联高免卵黄抗体。应用该高免卵黄抗体对1月龄鸡只进行预防免疫 ,攻毒治疗试验。试验结果表明 ,预防ND免疫保护率可达87 -100% ,治疗保护率达73%以上 ;预防AI免疫保护率可达100 % ,治疗保护率达80%。

Preparation and Application of Monoclonal Antibodies Specific for Salicylic Acid

Salicylic acid (SA) is widely distributed in many monocots and dicots and has many physiological effects. It can induce heat production in the thermogenic inflorescences of Arum lily([1]), block the biosynthesis of ethylene, and more attractively, it seems to be an important natural signal molecule in the induction of systemic acquired resistance (SAR) in tobacco, cucumber and other plants([2,3]). Studies in recent years showed that SA was also intimately related to the resistance of plants to aboitic stress, for example, SA increased chilling resistance of maize seedlings. Hence, SA has been accepted as a kind of new plant hormones. Up to date, the quantification of SA usually has been performed by HPLC[4,5], which often needs a large quantity of sample and a verbose pretreatment. Compared to HPLC, immunoassays, including radio-immunoassays (RIA) and enzyme-immunoassays (EIA), are easy to perform and have been widely used in the quantification of other plant hormones, such as IAA([6]), ABA([7,8]), GAs([9]), cytokinins et al([10]), and jasmonic acid (JA)([11]), and other low-molecular-weight, none-immunogenic compounds in plants([12]). Till now, only an indirect enzyme-linked immunosorbent assay (ELISA) for SA based on polyclonal antibodies (PAbs) has been developed by our group([13]), although Bennett et al([14]) had prepared SA PAbs using 4-aminosalicylic acid linked to KLH as immunogen in goat. However, the sensitivity of the ELISA we established formerly was relatively low, and also relatively larger quantity of sample is needed than other ELISAs for plant hormones. In this paper, an ELISA for SA based on monoclonal antibody raised against SA-NH-CH2-NH-KLH was introduced, and the fluctuation of SA content in cucumber leaves after inoculated with Pseudomonas syringae pv. syringae was determined.

Serum Treponema lgM Antibody Test for Syphilis Diagnoss

Objective: To evaluate the clinical utility of testingserum anti-treponema pallidum IgM antibody in thediagnosis of syphilis patients. Methods: Seventy-two cases of syphilis were testedfor specific IgM antibody with ELISA, and the resultswere compared with RPR and TPPA. Results: The sensitivity of IgM antibody was 73.3%(11/15) in primary syphilis, 88.9% (16/18) in sec-ondary syphilis, and there was no significant differ-ence between these values (x^2=1.6363, P>0.10). Thesensitivity of IgM antibody in diagnosing latent syphi-lis was only 26.1% (6/23), much lower than the detec-tion rate in symptomatic early syphilis (x^2=17.6189, P<0.005). RPR and TPPA were both 100% sensitive inlatent and early symptomatic syphilis. Two were posi-tive for IgM in the 16 cases who had received regulartreatments 2 to 24 months before enrolled. Conclusions: Specific IgM antibody detection doesnot appear superior to RPR and TPPA in diagnosingprimary syphilis. The diagnosis of latent syphilisshould mainly rely on RPR and TPPA, since there arelow titers of IgM antibody at that stage. IgM antibodytesting alone should not be recommended for monitor-ing syphilis development or treatment efficacy. Fur-ther studies should be concerned.

Primary Study of Egg Yolk Antibody for Detection of King Cobra Venom Antigens

Aim To study whether antivenom from laying hens can be used for the detection of venom antigens, Methods Chickens （white Leghorn） were immunized with detoxicated king cobra venom by formaldehyde and egg yolk immunoglobulin （IgY） isolated from yolk; IgY was labelled with the horseradish peroxidase （HRP）. Experimental condition and parameters were determined by chessboard test. The specificity, sensitivity, precision, and stability of this method were assayed in the experiment. Results This method could detect as low as 32 μg· L^-1 of the king cobra antigens. A good linear relation was found within 32 ～ 750 μg· L^-1 of king cobra venom concentrations （ r = 0. 963）. There was no cross reactivity for the reagents with Agkistrodon acutus Guenther venom or Vipera russelli siamensis Smith venom;slight cross reactivity .with Bungarus multicinctus Blyth venom or Bungarus fasciatus Chmeider venom; and notable cross reactivity with cobra venom. The average intra-assay relative standard deviation （RSD） was 1% - 3%, and the inter-assay RSD was less than 8%. The reagents （including IgY and HRP-IgY） were stable; no differences （P 〉 0.05） were observed for the detection of venom antigens when the reagents were stored at 37 ℃ up to 6 d. Conclusion IgY is a good reagent for diagnosis of snakebite after eliminating the genus cross reactivity.

Genetic Analysis of the P1 Region of Human Enterovirus 71 Strains and Expression of the 55 F StrainVP1 Protein

Enterovirus 71 （EV71） is a member of the Entero-virus genus of the Picomaviridae family and is the major cause of Hand, foot, and mouth disease （HFMD） in children. Different strains from Gansu were cloned and the P1 protein was sequenced and analysed. Results indicate that there are three kinds of EV71 infections prevalent in Gansu. The VP 1 protein from one of these strains, 55F, was expressed. The recombinant protein was expressed with high level and reacted specifically with the EV71 patient antibody, the recombinant protein was also applied to raise antiserum in rabbits and after the fourth injection a high titer of antiserum was detected by ELISA assay. These data are useful for further clarification of prevalent EV71 strains in the north of China at the molecular level and provide a basis for EV71 diagnosis.

Secretory Expression of E2 Main Antigen Domain of CSFV C Strain and the Establishment of Indirect ELISA Assay

The sequence encoding an E2 main antigen glycoprotein of the C strain of classical swine fever virus (CSFV) was highly expressed in the host cell E. coli BL21–CodonPlus (DE3)–RIL using the pGEX-4T-1 expression vector and the soluble recombinant product was purified with Glutathione Sepharose TM4B by centrifugation. The soluble recombinant protein showed good immune reactions and was confirmed by Western blot using anti-CSFV-specific antibodies. Then an indirect ELISA with the purified E2 protein as the coating antigen was established to detect antibody against CSFV. The result revealed that the optimal concentration of coated antigen was 0.6 μg/well and the optimal dilution of serum was 1:80. The positive cut-off value of this ELISA assay was OD tested serum / OD negative serum≥2.1. The E2-ELISA method was evaluated by comparison with the indirect hemagglutination test (IHAT). When a total of 100 field serum samples were tested the sensitivity and specificity were 90.3% and 94.7% respectively. Specificity analysis showed that there were no cross-reactions between BVD serum and the purified E2 protein in the E2-ELISA.

Development of a Fast ELISA for the Specific Detection of both Leucomalachite Green and Malachite Green

Malachite green(MG), a dye, is an antifungal agent that has been used to treat and prevent fish diseases. It is metabolized into reduced leucomalachite green forms(LMG) that may reside in fish muscles for a long period, thus being harmful to human health. The aim of this study was to develop a competitive and direct enzyme-linked immunosorbent assay(ELISA) to detect MG and LMG specifically. The monoclonal antibody(m Ab) to LMG was generated using a hybridoma technique. The obtained m Ab showed good cross-reactivity(CR) to malachite green(MG), but not to crystal violet(CV) and Brilliant Green(BG). The m Ab was used to develop a fast detecting ELISA of MG and LMG in fish. By introducing the conjugation LMG-HRP, the detection capability was 0.37 ng m L-1 for MG and LMG. The mean recovery from spiked grass carp tissues ranged from 76.2% to 82.9% and the coefficients of variation varied between 1.8% and 7.5%. The stable and efficient monoclonal cell line obtained is a sustainable source of sensitive and specific antibody to MG and LMG.

Intramuscular vs intradermal route for hepatitis B booster vaccine in celiac children

AIM： To compare intradermal （ID） and intramuscular （IM） booster doses, which have been used in healthy and high risk subjects, such as healthcare workers, haemodialysis patients, human immunodeficiency virus patients, and renal transplant recipients unresponsive to initial hepatitis B vaccination, in celiac individuals. METHODS： We conducted our study on 58 celiac pa- tients, vaccinated in the first year of life, whose blood analysis had showed the absence of protective hepati- tis B virus （HBV） antibodies. All patients had received the last vaccine injection at least one year before study enrolment and they had been on a gluten free diet for at least 1 year. In all patients we randomly performed an HBV vaccine booster dose by ID or IM route. Thirty celiac patients were revaccinated with recombinant hepatitis B vaccine （Engerix B） 2 μg by the ID route, while 28 celiac patients were revaccinated with Engerix B 10 μg by the IM route. Four weeks after every boost- er dose, the anti-hepatitis B surface （HBs） antibody titer was measured by an enzyme-linked immune- adsorbent assay. We performed a maximum of three booster doses in patients with no anti-HBs antibodies after the first or the second vaccine dose. The cut off value for a negative anti-HBs antibody titer was 10 IU/L.Patients with values between 10 and 100 IU/L were considered ＂low responders＂ while patients with an antibody titer higher than 1000 IU/L were considered ＂high responders＂. RESULTS： No significant difference in age, gender, du- ration of illness, and years of gluten intake was found between the two groups. We found a high percent- age of ＂responders＂ after the first booster dose （ID = 76.7%, IM = 78.6%） and a greater increase after the third dose （ID = 90%, IM = 96.4%） of vaccine in both groups. Mloreover we found a significantly higher num- ber of high responders （with an anti-HBs antibody titer 〉 1000 IU/L） in the ID （40%） than in the IM （7.1%） group, and this difference was evident after the first booster dose of vaccination （P 〈 0.01）. No side effects were recorded in performing delivery of the vaccine by either the ID or IM route. CONCLUSION： Our study suggests that both ID and IM routes are effective and safe options to administer a booster dose of HBV vaccine in celiac patients. Howev- er the ID route seems to achieve a greater number of high responders and to have a better cost/benefit ratio.

Incidence of toxoplasmosis in patients with cirrhosis

AIM:It is known that toxoplasmosis rarely leads to various liver pathologies,most common of which is granulomatose hepatitis in patients having normal immune systems.Patients who have cirrhosis of the liver are subject to a variety of cellular as well as humoral immunity disorders.Therefore,it may be considered that toxoplasmosis can cause more frequent and more severe diseases in patients with cirrhosis and is capable of changing the course of the disease.The aim of this study was to investigate the frequency of toxoplasmosis in patients with cirrhosis. METHODS:Serum samples were taken from 108 patients with cirrhosis under observation in the Hepatology Polyclinic of the Gastroenterology Clinic,and a control group made up of 50 healthy blood donors.IFAT and ELISA methods were used to investigate the IgG and IgM antibodies,which had developed from these sera. RESULTS:Toxoplasma IgG and IgN antibody positivity was found in 74 (68.5%) of the 108 cirrhotic patients and 24 (48%) of the 50 people in the control group.The difference between them was significant (P<0.05). CONCLUSION:In conclusion,it was found that the toxopiasma sero-prevalence in the cirrhotic patients in this study was higher.Cirrhotic patients are likely to form a toxoplasma risk group.More detailed studies are needed on this subject.

Adenovirus-expressed preS2 antibody inhibits hepatitis B virus infection and hepatic carcinogenesis

AIM:To investigate the inhibitory effect of hepatitis B virus (HBV) preS2 antibody (preS2Ab) against HBV in-fection and HBV-associated hepatic carcinogenesis.METHODS:An adenoviral vector carrying the full-length light and heavy chains of the HBV preS2Ab gene,Ad315-preS2Ab,was constructed.Enzyme linked immunosorbent assay (ELISA) and Western blotting analyses were used to determine the preS2Ab expres-sion levels in vitro.Immunofluorescent techniques were used to examine the binding affinity between the expressed HBV preS2Ab and HBV-positive liver cells.ELISAs were also used to determine hepatitis B surface antigen (HBsAg) levels to assess the inhibitory effect of the preS2Ab against HBV infection in L02 cells.The inhibitory effect of preS2Ab against hepatic carcinogen-esis was studied with diethylnitrosamine (DEN)-induced hepatocellular carcinomas (HCCs) in HBV transgenic mice.RESULTS:The expression of HBV preS2Ab increased with increases in the multiplicity of infection (MOI) of Ad315-preS2Ab in L02 cells,with 350.87 ± 17.37 μg/L of preS2Ab when the MOI was 100 plaque forming units (pfu)/cell.The expressed preS2Abs could recog-nize liver cells from HBV transgenic mice.ELISA results showed that L02 cells expressing preS2Ab produced less HBsAg after treatment with the serum of HBV pa-tients than parental L02 cells expressing no preS2Ab.HBV transgenic mice treated with Ad315-preS2Ab had fewer and smaller cancerous nodes after induction with DEN than mice treated with a blank Ad315 vec-tor or untreated mice.Additionally,the administration of Ad315-preS2Ab could alleviate hepatic cirrhosis and decrease the serum levels of alanine transaminase and aspartate transaminase.CONCLUSION:Adenovirus-mediated HBV preS2Ab expression could inhibit HBV infection in L02 cells,and then inhibit DEN-induced hepatocellular carcinogenesis and protect hepatic function in HBV transgenic mice.

Indirect ELISA with Recombinant GP5 for Detecting Antibodies to Porcine Reproductive and Respiratory Syndrome Virus

Porcine reproductive and respiratory syndrome is caused by the PRRS virus (PRRSV),which has six structural proteins (GP2,GP3,GP4,GP5,M and N). GP5 and N protein are important targets for serological detection by enzyme-linked immunosorbent assay (ELISA) and other methods. Toward this goal,we developed an indirect ELISA with recombinant GP5 antigens and this method was validated by comparison to the LSI PRRSV-Ab ELISA kit. The results indicated that the optimal concentration of coated recombinant antigen was 0.2 μg/well for a serum dilution of 1:40. The rate of agreement with the LSI PRRSV-Ab kit was 88.7% (266/300). These results support the potential use of recombinant GP5 as an antigen for indirect ELISA to detect PRRSV antibodies in pigs.

Affinity peptide developed by phage display selection for targeting gastric cancer

AIM:To develop an affinity peptide that binds to gastric cancer used for the detection of early gastric cancer.METHODS:A peptide screen was performed by biopanning the PhD-12 phage display library,clearing non-specific binders against tumor-adjacent normal appearing gastric mucosa and obtaining selective binding against freshly harvested gastric cancer tissues.Tumortargeted binding of selected peptides was confirmed by bound phage counts,enzyme-linked immunosorbent assay,competitive inhibition,fluorescence microscopy and semi-quantitative analysis on immunohistochemistry using different types of cancer tissues.RESULTS:Approximately 92.8% of the non-specific phage clones were subtracted from the original phage library after two rounds of biopanning against normal-appearing gastric mucosa.After the third round of positive screening,the peptide sequence AADNAKTKSFPV(AAD) appeared in 25%(12/48) of the analyzed phages.For the control peptide,these values were 6.8 ± 2.3,5.1 ± 1.7,3.5 ± 2.1,4.6 ± 1.9 and 1.1 ± 0.5,respectively.The values for AAD peptide were statistically signif icant(P < 0.01) for gastric cancer as compared with other histological classif ications and control peptide.CONCLUSION:A novel peptide is discovered to have a specific binding activity to gastric cancer,and can be used to distinguish neoplastic from normal gastric mucosa,demonstrating the potential for early cancer detection on endoscopy.

B Cell Epitopes within VP1 of Type O Foot-and-mouth Disease Virus for Detection of Viral Antibodies

In this study, the coding region of type O FMDV capsid protein VP1 and a series of codon optimized DNA sequences coding for VP1 amino acid residues 141-160 （epitopel）, tandem repeat 200-213 （epitope2 （＋2）） and the combination of two epitopes （epitopel-2） was genetically cloned into the prokaryotic expression vector PPRoExHTb and pGEX4T-1, respectively. VP1 and the fused epitopes GST-E1, GST-E2 （＋2） and GST-E1-2 were successfully solubly expressed in the cytoplasm of Escherichia coli and Western blot analysis demonstrated they retained antigenicity. Indirect VP1-ELISA and epitope ELISAs were subsequently developed to screen a panel of 80 field pig sera using LPB-ELISA as a standard test. For VP1-ELISA and all the epitope ELISAs, there were clear distinctions between the FMDV-positive and the FMDV-negative samples. Cross-reactions with pig sera positive to the viruses of swine vesicular disease virus that produce clinically indistinguishable syndromes in pigs or guinea pig antisera to FMDV strains of type A, C and Asia1 did not occur. The relative sensitivity and specificity for the GST-E1 ELISA, GST-E2 （＋2）, GST-E1-2 ELISA and VP1-ELISA in comparison with LPB-ELISA were 93.3% and 85.0%, 95.0% and 90%, 100% and 81.8%, 96.6% and 80.9% respectively. This study shows the potential use of the aforementioned epitopes as alternatives to the complex antigens used in current detection for antibody to FMDV structural proteins.

PREPARATION AND CHARACTERIZATION OF MONOCLONAL ANTIBODY AGAINST HUMAN TELOME RASE REVERSE TRANSCRIPTASE

Objective.To develop monoclonal antibodies again st the catalytic subunit of human telomerase reverse transcriptasefor i ts expression detection of human tumors.Methods.A dominant epitope in hTERT was automatically synthesized based on Fmoc method,and was used to immuni ze Balb/c mice.Hybridomas were generated and screened by ELISA for specific mo noclonal antibodies,and the characterization was performed by Western blotting and immunohistochemical staining.The heavy chain variable region of antibody wa s cloned by RT-PCR and sequenced.Results.Antigenic peptide hTERT 7 was synthesized and confirmed by MALDI-TOF-MS and HPLC analysis.One hybr idoma cell line secreting anti-hTERT 7 antibodies designated as M2was established after primary screening and cons equent 3rounds of limited dilution.M2was IgG1in isotyping.The competi-tive assay showed that the M2antibody was hTERT 7-specific,and the affinity constant was about 1×10 6 mol-1 .The antibody reacted with cell extracts from HeLa cancer cells but not wi th those from normal2BS cells in ELISA assay.For in situ staining of immunohis tochemistry,the positive staining presented in the nuclear compartment of HeLa ,while2BS was negative.The heavy chain variable region from M2re-vealed tha t the monoclonal antibody was mouse origin.Conclusions.The developed mouse mon oclonal antibody is hTERT-specific and able to recognize native cellular hTERT in ELISA and immunohistochemistry,which makes the immuno-detection of telom-e rase hTERT expression in cancer cells or tissues possible.

Determination of Postvaccinal Antibodies Against OspA B. afzelii, B. garinfi and B. burgdorferi sensu stricto Using Elisa Method

The specific recombinant proteins rOspA B. afzelii, rOspA B. garinii a rOspA B. burgdorferi sensu stricto were used as antigens for construction of ELISA sets. ELISA examination enables determination of specific post-vaccination antibodies against OspA B. afzelii, B. garinii a B. burgdorferi sensu stricto.Using recombinant DNA technology, genes from B. afzelii, B. garinii and B. burgdorferi sensu stricto were inserted into E. coli-expression vectors and the rOspA proteins were produced. These proteins were used for the construction of ELISA kits for the determination of post-vaccination antibodies against individual Borrelia serovars contained in the vaccine. The antibody response of dogs vaccinated with whole-cell vaccine BORRELYM 3 and non-vaccinated dogs was monitored and compared. The ELISA method proved as highly sensitive for the determination of post-vaccination antibodies against individual Borrelia serovars in vaccinated animals. Detection of these antibodies and their quantification may be used for evaluation of efficiency of vaccines against Lyme borreliosis in dogs caused by Borrelia burgdorferi sensu lato. Prospectively, it will be necessary to establish a correlation between post-vaccination antibody levels and protective immunity of vaccinated dogs.

Production of a monoclonal antibody against oxytetracycline and its application for oxytetracycline residue detection in shrimp

A novel monoclonal antibody （MAb） against oxytetracycline （OTC） was generated and characterized. The MAb was used in the development of an enzyme-linked immunosorbant assay （ELISA）-based detection system. An OTC-bovine serum albumin （BSA） conjugate was prepared and used in the immunization of mice. A conventional somatic cell fusion technique was used to generate MAb-secreting hybridomas denoted 2-4F, 7-3G, and 11-11A. An indirect competitive ELISA （icELISA） was applied to measure the sensitivity and specificity of each MAb in terms of its 50% inhibitory concentration （IC50） and percentage of cross-reactivity, respectively. MAb 2-4F exhibited the highest sensitivity, with an ICs0 of 7.01 ng/ml. This MAb showed strong cross-reactivity to rolitetracycline, but no cross- reactivity to other unrelated antibiotics. When MAb 2-4F was used to detect OTC from shrimp samples, the recoveries were in the range of 82%-118% for an intra-assay and 96%-113% for an inter-assay. The coefficients of variation of the assays were 3.9%-13.9% and 5.5%-14.9%, respectively.