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,c...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.展开更多
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 facto...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.展开更多
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 optim...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.展开更多
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 G...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.展开更多
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 amplif...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.展开更多
[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 ...[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.展开更多
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...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.展开更多
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 app...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.展开更多
Objective: To investigate the serum levels of soluble macrophage colony-stimulating factor receptor (M-CSFsR) in normal subjects and patients with hematological diseases and its clinical implications in hematological ...Objective: To investigate the serum levels of soluble macrophage colony-stimulating factor receptor (M-CSFsR) in normal subjects and patients with hematological diseases and its clinical implications in hematological diseases. Methods: The concentration of M-CSFsR was determined by ELISA. The serum M-CSFsR was identified and characterized by immunoprecipitation and Western blotting. Results: The mean serum level of M-CSFsR of 123 normal individuals was 0.48 ng/ml ± 0.41 ng/ml. Immunoprecipitation and Western blotting assay revealed a ～ 90kD band of serum M-CSFsR. The mean serum M-CSFsR level of 60 patients with acute lymphoblastic leukemia (ALL), 36 patients with acute myeloblastic leukemia (AML), 13 patients with myelodysplastic syndrome (MDS) and 42 patients with aplastic anemia (AA) .were 0.22 ng/ml±0.23 ng/ml, 0.17 ng/ml±0.16 ng/ml, 0.19 ng/ml±0.16 ng/ml and 0.23 ng/ml±0.21 ng/ml, respectively, which were significantly lower than that of normal subjects (P=0.002 ,P<0.0001,P<0.0001 andP<0.0001). The mean serum M-CSFsR level of 51 idiopathic thrombocytopenic purpura (ITP) patients was significantly higher than that of normal subjects (2.05 ng/ml±2.75 ng/ml,P<0.0001). Conclusion: The serum M-CSFsR levels of patients with ALL, AML, MDS and AA were significantly lower, while the level of patients with ITP was significantly higher than that of normal individuals. Patients with severe ITP (platelet count<30×l09/L) had the highest M-CSFsR level. It suggested that the abnormal levels of serum M-CSFsR may associate with some hematological diseases and may contribute to the pathological process.展开更多
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 subje...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.展开更多
The value of ELISA, N-PCR and RT-PCR in clinical practice for pregnant women with HCMV infection was investigated. 5581 pregnant women were screened by ELISA. Among them, 100 cases were positive for IgM (group 1). 69 ...The value of ELISA, N-PCR and RT-PCR in clinical practice for pregnant women with HCMV infection was investigated. 5581 pregnant women were screened by ELISA. Among them, 100 cases were positive for IgM (group 1). 69 for both IgM and serous DNA (group 2) and 69 for both IgM and mRNA (group 3). The infectious status, maternal-fetal transmission and pregnancy outcome were monitored. It was demonstrated that the accordance rate of group 3 and group 2 with group 1 was 56. 25 % and 43. 75 % , respectively. The maternal-fetal transmission rate in the group 1, 2 and 3 was 19. 00 % , 40. 58 % and 46. 15 %, respectively, with a significant difference found between group 2, 3 and group 1 (P<0. 01). Incidence of spontaneous abortion, fetal death, fetal abnormality and neonatal death in group 1, 2 and 3 was 10. 00 %, 15. 94 % and 30. 77 %, respectively, and that of group 3, 2 was 4 and 2 times as much as that of group 1, respectively (OR = 4. 00, P<0. 001; OR=2. 343, P<005, respectively). It was concluded that HCMV-IgM(+) can only be considered as an screening indicator for pregnant women with HCMV infection, while IgM(+) combined with serous DNA( + ) or mRNA( + ) indicates active infection and has a high incidence of maternal-fetal transmission and abnormal pregnancy outcome.展开更多
[ Objective] To develop an indirect ELISA assay for detecting antibodies against envelope glycoprotein （ E protein） of Japanese encephalitis virus （JEV）. [ Method] Specific primers were designed according to JEV s...[ Objective] To develop an indirect ELISA assay for detecting antibodies against envelope glycoprotein （ E protein） of Japanese encephalitis virus （JEV）. [ Method] Specific primers were designed according to JEV sequences published in the GenBank. The cDNA of JEV E gene （about 1 000 10p） was amplified by the RT-PCR with the specific primers. After sequencing analysis, the E gene was cloned into pET30a expression vector and expressed in E. coli BL21 （DE3） with the induction of IPTG. After denaturation, purification and renaturation, the recombinant protein was analyzed by the SDS-PAGE and the westem blotting. An indirect ELISA was developed to detect antibodies against JEV. [ Result] The E protein was mainly expressed in inclusion body. With the purified E protein, the indirect ELISA was developed and displayed good specificity, sensitivity and repeatability, [ Conclusion]The developed ELISA using the truncated E protein as antigen is a simple, convenient and rapid serological method for diagnosis, monitoring antibody level and epidemiological investigation of JEV.展开更多
The purpose of this study was to develop a method for detecting antibodies against porcine pseudorabies virus （PRV）. According to the published genomic sequence of PRV SA strain, an approximately 1 070-bp gD gene fr...The purpose of this study was to develop a method for detecting antibodies against porcine pseudorabies virus （PRV）. According to the published genomic sequence of PRV SA strain, an approximately 1 070-bp gD gene fragment was amplified by PCR. The PCR products were cloned into the prokaryotic expression vector pET30a and the positive recombinant plasmid was transformed into E. coli BL21. Through induction with IPTG, the recombinant gD protein was expressed as inclusion bodies. As analyzed by western blot assay, the purified recombinant gD protein had good antigenicity and high specificity. Using the purified gD protein as coating antigen and horseradish peroxidase labeled staphylococcal protein A （PPA） as secondary antibody, we developed a PPA-ELISA for detecting antibodies against porcine PPV. No cross-reaction with the positive sera against seven common pathogens in pigs including classical swine fever virus, porcine parvovirus, porcine reproductive and respiratory syndrome, Japanese encephalitis virus, porcine circovirus type 2, porcine epidemic diarrhea virus, transmissible gastroenteritis virus was observed. The repeatability test showed that the intra- and inter-assay coefficients of variation were lower than 5% and 10%, respectively. Compared with the ELISA gD antibody test kit produced by IDEXX, the coincidence, sensitivity and specificity of the developed PPA-ELISA were 92.0%, 95.1% and 88.1%, respectively. The developed PPA-ELISA had good repeatability, sensitivity and specificity and was a rapid and simple serological method for surveillance of PRV antibodies in pig herds as well as for rapid diagnosis and epidemiological investigation of PRV infection.展开更多
<strong>Objective:</strong> To evaluate three different serological tests [Indirect Hemaglutination (IHA), Enzyme Linked Immunosorbent Assay (ELISA) and Western Blotting (WB)] using native crude antigen fo...<strong>Objective:</strong> To evaluate three different serological tests [Indirect Hemaglutination (IHA), Enzyme Linked Immunosorbent Assay (ELISA) and Western Blotting (WB)] using native crude antigen for diagnosis of hepatic cystic echinococcosis (HCE) patients. <strong>Materials and Methods:</strong> Sheep hydatid fluid (HF) was collected from fertile cysts obtained from a slaughterhouse and used as an antigen. Forty patients who were attended the Dr. Ersin Arslan Training and Research Hospital in Gaziantep, Turkey, were investigated. Serum samples were obtained from surgically confirmed CE patients. Healthy Turkish people and 16 patients with other helminthic infections were included as a control group. <strong>Results:</strong> Of the 40 analyzed patients, 10 (25%) were men and 30 (75%) were female. The average age was 46.97 years (s.d.;18.95). The majority of the patients had a single cystic lesion situated in one lobe of the liver (usually in the right lobe) (55%), 32.5% of patients had two cystic lesions and 12.5% of patients had multiple cyst formations with various numbers. In all cases, ultrasound (US) examinations were positive and the size of cysts was between 2.1 - 12.7 cm. Twenty-three patients of the total 40 patients were classified according to the WHO classification system based on US findings. According to the results of WB analysis, molecular weights of 8 kDa (80%), 12 kDa (80%), 22 - 24 kDa (97.5%), 26 kDa (97.5%), 34 kDa (100%), 36 - 38 kDa (90%), 45 - 50 - 55 kDa (97.5%), and 60 - 75 kDa (97.5%) bands were identified. But 34, 50, and 55 kDa bands were also found in other helminthic diseases. <strong>Conclusion:</strong> The specificity and sensitivity of three serological tests (IHA, ELISA and WB) using crude antigen were compared by diagnosing hepatic cystic echinococcosis patients. IHA and ELISA showed high sensitivity but low specificity. Western blotting showed low sensitivity but high specificity.展开更多
Objective: To study the therapeutic mechanism of Santeng Dingtong recipe (STDT) on monosodium urate crystal (MSU) induced rabbit arthritis Methods: Forty-two rabbits were randomly divided into six groups, 7 in each gr...Objective: To study the therapeutic mechanism of Santeng Dingtong recipe (STDT) on monosodium urate crystal (MSU) induced rabbit arthritis Methods: Forty-two rabbits were randomly divided into six groups, 7 in each group. Group 1 received 0.9% saline 2. 5 ml/kg per day by gastrogavage (ig) for 10 days; Group 2, 3 and 4 received STDT 0.125 g/kg, 1.0 g/kg and 8.0 g/kg per day respectively by ig for 10 days; Group 5 received colchicine 4. 5 mg/kg per day by ig for 4 days; and Group 6 was untreated. MSU crystals 10 mg /500ul containing polymyxin B 10 u/ml was injected into the knee joints of Group 1-5 to make rabbit arthritis models. Leukocytes in synovial lavage fluids was then counted and differentiated; pathological injury of synovial membranes was observed under HE staining; interleukin-1 beta (IL-1B), tumor necrosis factor alpha (TNFa) and leukotriene B4 (LTB4) content in synovial lavage fluids were determined by ELISA. Results: MSU caused a rapid leukocyte infiltration and increased production of IL-1B, TNFa and LTB4 2 hrs after intra-articular injection. STDT inhibited neutrophil infiltration in synovial fluids dose-dependently, protected the synovial membrane against pathological injury and reduced the production of IL-1B, TNFa and LTB4; while colchicine did not decrease the level of TNFa, but significantly inhibited neutrophil infiltration in synovial fluid and reduced the production of IL-11B and LTB4. Conclusion: STDT exerts an anti-inflammatory effect in rabbit model of acute MSU arthritis, its mechanism being probably due to the decrease of XL-1B, TNFa and LTB4 synthesis.展开更多
Objective: To evaluate the interaction between serum levels of soluble intercellular adhesion molecule 1 (sICAM 1) and Helicobacter pylori (H. pylori) infection in patients with chronic gastritis and peptic ulc...Objective: To evaluate the interaction between serum levels of soluble intercellular adhesion molecule 1 (sICAM 1) and Helicobacter pylori (H. pylori) infection in patients with chronic gastritis and peptic ulcer. Methods: The serum levels of sICAM 1 in 205 patients with chronic gastric diseases were detected by ELISA method and the status of H. pylori was determined by histologic examination, RUT, 14 C UBT, and serology. The sera obtained from 18 healthy volunteers served as controls. Results: The serum levels of sICAM 1 were significantly higher in patients with H. pylori positive than those of H. pylori negative (889.43±32.52 ng/ml vs. 747.07±30.45 ng/ml, P <0.05). The serum levels of sICAM 1 in patients with mild, moderate and severe infection of H. pylori were 841.68±72.36 ng/ml, 905.43±37.59 ng/ml and 1012.54±49.34 ng/ml,respectively ( P <0.05). The serum levels of sICAM 1 proved to be significantly correlated with the density of H. pylori colonization in gastric mucosa ( r s =0.316, P < 0.001) . The serum levels of sICAM 1 in patients with chronic gastritis and peptic ulcer were significantly higher than those in healthy controls ( P <0.05). Conclusions: These results indicated that H. pylori infection up regulates the expression of sICAM 1.展开更多
[Objective] To develop a new method for serodiagnosis of swine toxoplasmosis. [Method] With the purified recombinant microneme protein 3 （rMIC3） as coating antigens, an indirect ELISA was developed for detection of ...[Objective] To develop a new method for serodiagnosis of swine toxoplasmosis. [Method] With the purified recombinant microneme protein 3 （rMIC3） as coating antigens, an indirect ELISA was developed for detection of antibodies against Toxoplasma gondii. [ Result] The optimal working concentration of rMIC3 was 3. 40 ug/ml, and the optimal degree of dilution of sera was 1：160. Cross-reaction was not observed between the Toxoplasma gondii-positive sera and the positive sera against classical swine fever virus or some other pathogens. The developed ELISA had 92.56% coincidence rate with latex agglutination test. [ Conclusion] The developed ELISA is sensitive, rapid, specific and reproducible, and thus it can be applied in serodiagnosis and seroprevalence investigation of swine toxoplasmosis.展开更多
[Objectives]This study was conducted to develop an enzyme-linked immunoassay kit that can detect the residual amount of pentachloronitrobenzene in Penaeus vannamei.[Methods]This study was conducted to develop an enzym...[Objectives]This study was conducted to develop an enzyme-linked immunoassay kit that can detect the residual amount of pentachloronitrobenzene in Penaeus vannamei.[Methods]This study was conducted to develop an enzyme-linked immunoassay kit that can detect the residual amount of pentachloronitrobenzene in P.vannamei.[Results]The standard curve range of the kit was 0-8.1μg/L;the detection limit for P.vannamei was 0.912μg/kg;the recovery was 80.6%-103.5%;and the relative standard deviation range within batches was 5.3%-10.1%,and the relative standard deviation range between batches was 6.7%-8.1%.The specificity of the pentachloronitrobenzene monoclonal antibody was relatively good,and the cross-reaction rates with pentachlorophenol,hexachlorobenzene,tetrachlorophthalide,and chlorothalonil were low,all of which did not exceed 30%.The ELISA kit could be stored at 4℃for 12 months,showing good stability.[Conclusions]The detection kit has low cost,short time and small deviation,and is an ideal preliminary screening method.展开更多
The importance of natural enemies as the foundation of integrated pest management （IPM） is widely accepted, but few studies conduct the manipulative field experiments necessary to directly quantify their impact on p...The importance of natural enemies as the foundation of integrated pest management （IPM） is widely accepted, but few studies conduct the manipulative field experiments necessary to directly quantify their impact on pest populations in this context. This is particularly true for predators. Studying arthropod predator-prey interactions is inherently difficult： prey items are often completely consumed, individual predator-prey interactions are ephemeral （rendering their detection difficult） and the typically fluid or soft-bodied meals cannot be easily identified visually within predator guts. Serological techniques have long been used in arthropod predator gut-contents analysis, and current enzyme linked immunosorbent assays （ELISA） are highly specific and sensitive. Recently, poly- merase chain reaction （PCR） methods for gut-contents analysis have developed rapidly and they now dominate the diagnostic methods used for gut-contents analysis in field-based research. This work has identified trophic linkages within food webs, determined predator diet breadth and preference, demonstrated the importance of cannibalism and intraguild predation within and between certain taxa, and confirmed the benefits （predator persis- tence） and potential disadvantages （reduced feeding on pest species） of the availability of alternative nonpest prey. Despite considerable efforts to calibrate gut-contents assays, these methods remain qualitative. Available techniques for predator gut-contents analysis can provide rapid, accurate, cost-effective identification of predation events. As such, they perfectly compliment the ecological methods developed to directly assess predator im- pacts on prey populations but which are imperfect at identifying the key predators. These diagnostic methods for gut-contents analysis are underexploited in agricultural research and they are almost never applied in unison with the critical field experiments to measure predator impact. This paper stresses the need for a combined approach and suggests a framework that would make this possible, so that appropriate natural enemies can be targeted in conservation biological control.展开更多
基金supported by the Central Government Guide Local Special Fund Project for Scientific and Technological Development of Jiangxi Province(20221ZDD02001).
文摘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.
基金Project supported by the National Natural Science Foundation of China (No. 30471155) the Agriculture Key Technologies R & D Program of Shanghai (No. (2003) 9-4), China
文摘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.
文摘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.
文摘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.
基金Financially supported by Key grant from the Education Committee of Hunan Province (No. 02A046)
文摘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.
基金Supported by Beijing Municipal Science and Technology Project(Z151100002115059)~~
文摘[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.
基金supported by National Natural Science Foundation of China(No.81272590)
文摘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.
文摘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.
基金National "863" High Technology Program of China ( 102-11-01-03).
文摘Objective: To investigate the serum levels of soluble macrophage colony-stimulating factor receptor (M-CSFsR) in normal subjects and patients with hematological diseases and its clinical implications in hematological diseases. Methods: The concentration of M-CSFsR was determined by ELISA. The serum M-CSFsR was identified and characterized by immunoprecipitation and Western blotting. Results: The mean serum level of M-CSFsR of 123 normal individuals was 0.48 ng/ml ± 0.41 ng/ml. Immunoprecipitation and Western blotting assay revealed a ～ 90kD band of serum M-CSFsR. The mean serum M-CSFsR level of 60 patients with acute lymphoblastic leukemia (ALL), 36 patients with acute myeloblastic leukemia (AML), 13 patients with myelodysplastic syndrome (MDS) and 42 patients with aplastic anemia (AA) .were 0.22 ng/ml±0.23 ng/ml, 0.17 ng/ml±0.16 ng/ml, 0.19 ng/ml±0.16 ng/ml and 0.23 ng/ml±0.21 ng/ml, respectively, which were significantly lower than that of normal subjects (P=0.002 ,P<0.0001,P<0.0001 andP<0.0001). The mean serum M-CSFsR level of 51 idiopathic thrombocytopenic purpura (ITP) patients was significantly higher than that of normal subjects (2.05 ng/ml±2.75 ng/ml,P<0.0001). Conclusion: The serum M-CSFsR levels of patients with ALL, AML, MDS and AA were significantly lower, while the level of patients with ITP was significantly higher than that of normal individuals. Patients with severe ITP (platelet count<30×l09/L) had the highest M-CSFsR level. It suggested that the abnormal levels of serum M-CSFsR may associate with some hematological diseases and may contribute to the pathological process.
基金supported by the National Natural Science Foundation of China,No.30770758
文摘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.
文摘The value of ELISA, N-PCR and RT-PCR in clinical practice for pregnant women with HCMV infection was investigated. 5581 pregnant women were screened by ELISA. Among them, 100 cases were positive for IgM (group 1). 69 for both IgM and serous DNA (group 2) and 69 for both IgM and mRNA (group 3). The infectious status, maternal-fetal transmission and pregnancy outcome were monitored. It was demonstrated that the accordance rate of group 3 and group 2 with group 1 was 56. 25 % and 43. 75 % , respectively. The maternal-fetal transmission rate in the group 1, 2 and 3 was 19. 00 % , 40. 58 % and 46. 15 %, respectively, with a significant difference found between group 2, 3 and group 1 (P<0. 01). Incidence of spontaneous abortion, fetal death, fetal abnormality and neonatal death in group 1, 2 and 3 was 10. 00 %, 15. 94 % and 30. 77 %, respectively, and that of group 3, 2 was 4 and 2 times as much as that of group 1, respectively (OR = 4. 00, P<0. 001; OR=2. 343, P<005, respectively). It was concluded that HCMV-IgM(+) can only be considered as an screening indicator for pregnant women with HCMV infection, while IgM(+) combined with serous DNA( + ) or mRNA( + ) indicates active infection and has a high incidence of maternal-fetal transmission and abnormal pregnancy outcome.
文摘[ Objective] To develop an indirect ELISA assay for detecting antibodies against envelope glycoprotein （ E protein） of Japanese encephalitis virus （JEV）. [ Method] Specific primers were designed according to JEV sequences published in the GenBank. The cDNA of JEV E gene （about 1 000 10p） was amplified by the RT-PCR with the specific primers. After sequencing analysis, the E gene was cloned into pET30a expression vector and expressed in E. coli BL21 （DE3） with the induction of IPTG. After denaturation, purification and renaturation, the recombinant protein was analyzed by the SDS-PAGE and the westem blotting. An indirect ELISA was developed to detect antibodies against JEV. [ Result] The E protein was mainly expressed in inclusion body. With the purified E protein, the indirect ELISA was developed and displayed good specificity, sensitivity and repeatability, [ Conclusion]The developed ELISA using the truncated E protein as antigen is a simple, convenient and rapid serological method for diagnosis, monitoring antibody level and epidemiological investigation of JEV.
基金funded by the Special Fund for Research and Development of Application Technology of Binzhou City(200706)Youth Science and Technology Innovation Fund of Shandong Binzhou Animal Science & Veterinary Medicine Academy (2007-02)
文摘The purpose of this study was to develop a method for detecting antibodies against porcine pseudorabies virus （PRV）. According to the published genomic sequence of PRV SA strain, an approximately 1 070-bp gD gene fragment was amplified by PCR. The PCR products were cloned into the prokaryotic expression vector pET30a and the positive recombinant plasmid was transformed into E. coli BL21. Through induction with IPTG, the recombinant gD protein was expressed as inclusion bodies. As analyzed by western blot assay, the purified recombinant gD protein had good antigenicity and high specificity. Using the purified gD protein as coating antigen and horseradish peroxidase labeled staphylococcal protein A （PPA） as secondary antibody, we developed a PPA-ELISA for detecting antibodies against porcine PPV. No cross-reaction with the positive sera against seven common pathogens in pigs including classical swine fever virus, porcine parvovirus, porcine reproductive and respiratory syndrome, Japanese encephalitis virus, porcine circovirus type 2, porcine epidemic diarrhea virus, transmissible gastroenteritis virus was observed. The repeatability test showed that the intra- and inter-assay coefficients of variation were lower than 5% and 10%, respectively. Compared with the ELISA gD antibody test kit produced by IDEXX, the coincidence, sensitivity and specificity of the developed PPA-ELISA were 92.0%, 95.1% and 88.1%, respectively. The developed PPA-ELISA had good repeatability, sensitivity and specificity and was a rapid and simple serological method for surveillance of PRV antibodies in pig herds as well as for rapid diagnosis and epidemiological investigation of PRV infection.
文摘<strong>Objective:</strong> To evaluate three different serological tests [Indirect Hemaglutination (IHA), Enzyme Linked Immunosorbent Assay (ELISA) and Western Blotting (WB)] using native crude antigen for diagnosis of hepatic cystic echinococcosis (HCE) patients. <strong>Materials and Methods:</strong> Sheep hydatid fluid (HF) was collected from fertile cysts obtained from a slaughterhouse and used as an antigen. Forty patients who were attended the Dr. Ersin Arslan Training and Research Hospital in Gaziantep, Turkey, were investigated. Serum samples were obtained from surgically confirmed CE patients. Healthy Turkish people and 16 patients with other helminthic infections were included as a control group. <strong>Results:</strong> Of the 40 analyzed patients, 10 (25%) were men and 30 (75%) were female. The average age was 46.97 years (s.d.;18.95). The majority of the patients had a single cystic lesion situated in one lobe of the liver (usually in the right lobe) (55%), 32.5% of patients had two cystic lesions and 12.5% of patients had multiple cyst formations with various numbers. In all cases, ultrasound (US) examinations were positive and the size of cysts was between 2.1 - 12.7 cm. Twenty-three patients of the total 40 patients were classified according to the WHO classification system based on US findings. According to the results of WB analysis, molecular weights of 8 kDa (80%), 12 kDa (80%), 22 - 24 kDa (97.5%), 26 kDa (97.5%), 34 kDa (100%), 36 - 38 kDa (90%), 45 - 50 - 55 kDa (97.5%), and 60 - 75 kDa (97.5%) bands were identified. But 34, 50, and 55 kDa bands were also found in other helminthic diseases. <strong>Conclusion:</strong> The specificity and sensitivity of three serological tests (IHA, ELISA and WB) using crude antigen were compared by diagnosing hepatic cystic echinococcosis patients. IHA and ELISA showed high sensitivity but low specificity. Western blotting showed low sensitivity but high specificity.
基金This program was supported by the National New Drugs Foundation(No.98-35-N-13)
文摘Objective: To study the therapeutic mechanism of Santeng Dingtong recipe (STDT) on monosodium urate crystal (MSU) induced rabbit arthritis Methods: Forty-two rabbits were randomly divided into six groups, 7 in each group. Group 1 received 0.9% saline 2. 5 ml/kg per day by gastrogavage (ig) for 10 days; Group 2, 3 and 4 received STDT 0.125 g/kg, 1.0 g/kg and 8.0 g/kg per day respectively by ig for 10 days; Group 5 received colchicine 4. 5 mg/kg per day by ig for 4 days; and Group 6 was untreated. MSU crystals 10 mg /500ul containing polymyxin B 10 u/ml was injected into the knee joints of Group 1-5 to make rabbit arthritis models. Leukocytes in synovial lavage fluids was then counted and differentiated; pathological injury of synovial membranes was observed under HE staining; interleukin-1 beta (IL-1B), tumor necrosis factor alpha (TNFa) and leukotriene B4 (LTB4) content in synovial lavage fluids were determined by ELISA. Results: MSU caused a rapid leukocyte infiltration and increased production of IL-1B, TNFa and LTB4 2 hrs after intra-articular injection. STDT inhibited neutrophil infiltration in synovial fluids dose-dependently, protected the synovial membrane against pathological injury and reduced the production of IL-1B, TNFa and LTB4; while colchicine did not decrease the level of TNFa, but significantly inhibited neutrophil infiltration in synovial fluid and reduced the production of IL-11B and LTB4. Conclusion: STDT exerts an anti-inflammatory effect in rabbit model of acute MSU arthritis, its mechanism being probably due to the decrease of XL-1B, TNFa and LTB4 synthesis.
文摘Objective: To evaluate the interaction between serum levels of soluble intercellular adhesion molecule 1 (sICAM 1) and Helicobacter pylori (H. pylori) infection in patients with chronic gastritis and peptic ulcer. Methods: The serum levels of sICAM 1 in 205 patients with chronic gastric diseases were detected by ELISA method and the status of H. pylori was determined by histologic examination, RUT, 14 C UBT, and serology. The sera obtained from 18 healthy volunteers served as controls. Results: The serum levels of sICAM 1 were significantly higher in patients with H. pylori positive than those of H. pylori negative (889.43±32.52 ng/ml vs. 747.07±30.45 ng/ml, P <0.05). The serum levels of sICAM 1 in patients with mild, moderate and severe infection of H. pylori were 841.68±72.36 ng/ml, 905.43±37.59 ng/ml and 1012.54±49.34 ng/ml,respectively ( P <0.05). The serum levels of sICAM 1 proved to be significantly correlated with the density of H. pylori colonization in gastric mucosa ( r s =0.316, P < 0.001) . The serum levels of sICAM 1 in patients with chronic gastritis and peptic ulcer were significantly higher than those in healthy controls ( P <0.05). Conclusions: These results indicated that H. pylori infection up regulates the expression of sICAM 1.
基金supported by the Key Research Project of the Ministry of Education (105120)Educational Commission of Hubei Province of China (B20091203)
文摘[Objective] To develop a new method for serodiagnosis of swine toxoplasmosis. [Method] With the purified recombinant microneme protein 3 （rMIC3） as coating antigens, an indirect ELISA was developed for detection of antibodies against Toxoplasma gondii. [ Result] The optimal working concentration of rMIC3 was 3. 40 ug/ml, and the optimal degree of dilution of sera was 1：160. Cross-reaction was not observed between the Toxoplasma gondii-positive sera and the positive sera against classical swine fever virus or some other pathogens. The developed ELISA had 92.56% coincidence rate with latex agglutination test. [ Conclusion] The developed ELISA is sensitive, rapid, specific and reproducible, and thus it can be applied in serodiagnosis and seroprevalence investigation of swine toxoplasmosis.
基金Key R&D Program of Hebei Province:Special Project on Key Common Technologies for High-quality Agricultural Development(20327505D).
文摘[Objectives]This study was conducted to develop an enzyme-linked immunoassay kit that can detect the residual amount of pentachloronitrobenzene in Penaeus vannamei.[Methods]This study was conducted to develop an enzyme-linked immunoassay kit that can detect the residual amount of pentachloronitrobenzene in P.vannamei.[Results]The standard curve range of the kit was 0-8.1μg/L;the detection limit for P.vannamei was 0.912μg/kg;the recovery was 80.6%-103.5%;and the relative standard deviation range within batches was 5.3%-10.1%,and the relative standard deviation range between batches was 6.7%-8.1%.The specificity of the pentachloronitrobenzene monoclonal antibody was relatively good,and the cross-reaction rates with pentachlorophenol,hexachlorobenzene,tetrachlorophthalide,and chlorothalonil were low,all of which did not exceed 30%.The ELISA kit could be stored at 4℃for 12 months,showing good stability.[Conclusions]The detection kit has low cost,short time and small deviation,and is an ideal preliminary screening method.
文摘The importance of natural enemies as the foundation of integrated pest management （IPM） is widely accepted, but few studies conduct the manipulative field experiments necessary to directly quantify their impact on pest populations in this context. This is particularly true for predators. Studying arthropod predator-prey interactions is inherently difficult： prey items are often completely consumed, individual predator-prey interactions are ephemeral （rendering their detection difficult） and the typically fluid or soft-bodied meals cannot be easily identified visually within predator guts. Serological techniques have long been used in arthropod predator gut-contents analysis, and current enzyme linked immunosorbent assays （ELISA） are highly specific and sensitive. Recently, poly- merase chain reaction （PCR） methods for gut-contents analysis have developed rapidly and they now dominate the diagnostic methods used for gut-contents analysis in field-based research. This work has identified trophic linkages within food webs, determined predator diet breadth and preference, demonstrated the importance of cannibalism and intraguild predation within and between certain taxa, and confirmed the benefits （predator persis- tence） and potential disadvantages （reduced feeding on pest species） of the availability of alternative nonpest prey. Despite considerable efforts to calibrate gut-contents assays, these methods remain qualitative. Available techniques for predator gut-contents analysis can provide rapid, accurate, cost-effective identification of predation events. As such, they perfectly compliment the ecological methods developed to directly assess predator im- pacts on prey populations but which are imperfect at identifying the key predators. These diagnostic methods for gut-contents analysis are underexploited in agricultural research and they are almost never applied in unison with the critical field experiments to measure predator impact. This paper stresses the need for a combined approach and suggests a framework that would make this possible, so that appropriate natural enemies can be targeted in conservation biological control.
