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
Objective:This investigation delineates the anti-cancer potency of epigallocatechin-3-gallate(EGCG)in an oral cancer mouse model,with a focus on its effect on T-cell activation.Methods:An oral cancer model was establi...Objective:This investigation delineates the anti-cancer potency of epigallocatechin-3-gallate(EGCG)in an oral cancer mouse model,with a focus on its effect on T-cell activation.Methods:An oral cancer model was established in male Balb/c mice using 4-nitroquinoline 1-oxide(4-NQO).The mice were systematically grouped and administered graded concentrations of EGCG.Key parameters such as body weight,hydration levels,tumor volume,and mass were meticulously tracked.T-cell activity and cytokine expression profiles,focusing on interleukin-2(IL-2),interferon-gamma(IFN-γ),and tumor necrosis factor-alpha(TNF-α),were quantified using ELISA.A comprehensive statistical evaluation included one-way ANOVA,Tukey’s HSD multiple comparison test,and the Kruskal-Wallis non-parametric assessment.Results:EGCG-administered cohorts exhibited a pronounced reduction in tumor size and mass,with the high-dose group showing the greatest efficacy.ELISA findings corroborated a significant increase in T-cell activity and concomitant upregulation of key cytokines,including IL-2,IFN-γ,and TNF-α(P<0.05).Conclusion:This investigation confirms the tumor-suppressive efficacy of EGCG in a murine oral squamous cell carcinoma model.The therapeutic effects of EGCG are mediated through T-cell activation and the upregulation of pivotal cytokine expression,highlighting its potential immunomodulatory role in oral cancer treatment.展开更多
BACKGROUND Defective neutrophil regulation in inflammatory bowel disease(IBD)is thought to play an important role in the onset or manifestation of IBD,as it could lead to damage of the intestinal mucosal barrier by th...BACKGROUND Defective neutrophil regulation in inflammatory bowel disease(IBD)is thought to play an important role in the onset or manifestation of IBD,as it could lead to damage of the intestinal mucosal barrier by the infiltration of neutrophils in the inflamed mucosa and the accumulation of pathogens.Like neutrophils in the context of innate immune responses,immunoglobulin A(IgA)as an acquired immune response partakes in the defense of the intestinal epithelium.Under normal conditions,IgA contributes to the elimination of microbes,but in connection with the loss of tolerance to chitinase 3-like 1(CHI3L1)in IBD,IgA could participate in CHI3L1-mediated improved adhesion and invasion of potentially pathogenic microorganisms.The tolerance brake to CHI3L1 and the occurrence of IgA autoantibodies to this particular target,the exact role and underlying mechanisms of CHI3L1 in the pathogenesis of IBD are still unclear.AIM To determine the predictive potential of Ig subtypes of a novel serological marker,anti-CHI3L1 autoantibodies(aCHI3L1)in determining the disease phenotype,therapeutic strategy and long-term disease course in a prospective referral cohort of adult IBD patients.METHODS Sera of 257 Crohn’s disease(CD)and 180 ulcerative colitis(UC)patients from a tertiary IBD referral center of Hungary(Division of Gastroenterology,Department of Internal Medicine,Faculty of Medicine,University of Debrecen)were assayed for IgG,IgA,and secretory IgA(sIgA)type aCHI3L1 by enzyme-linked immunosorbent assay using recombinant CHI3L1,along with 86 healthy controls(HCONT).RESULTS The IgA type was more prevalent in CD than in UC(29.2%vs 11.1%)or HCONT(2.83%;P<0.0001 for both).However,sIgA subtype aCHI3L1 positivity was higher in both CD and UC patients than in HCONT(39.3%and 32.8%vs 4.65%,respectively;P<0.0001).The presence of both IgA and sIgA aCHI3L1 antibodies was associated with colonic involvement(P<0.0001 and P=0.038,respectively)in patients with CD.Complicated disease behavior at sample procurement was associated with aCHI3L1 sIgA positivity(57.1%vs 36.0%,P=0.009).IgA type aCH3L1 was more prevalent in patients with frequent relapse during the disease course in the CD group(46.9%vs 25.7%,P=0.005).In a group of patients with concomitant presence of pure inflammatory luminal disease and colon involvement at the time of diagnosis,positivity for IgA or sIgA type aCH3L1 predicted faster progression towards a complicated disease course in time-dependent models.This association disappeared after merging subgroups of different disease locations.CONCLUSION CHI3L1 is a novel neutrophil autoantigenic target in IBD.The consideration of antibody classes along with location-based prediction may transform the future of serology in IBD.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
[Objective] The aim of this study was to study on expression of Bt protein in transgenic pest-resistant rice. [Method] Enzyme-linked immunosorbent assay (ELISA) was used to measure Bt protein expression in different...[Objective] The aim of this study was to study on expression of Bt protein in transgenic pest-resistant rice. [Method] Enzyme-linked immunosorbent assay (ELISA) was used to measure Bt protein expression in different tissues of transgenic pest-resistant rice at same growth stage. [Result] Absolute content of Bt protein from high to low was as follows: leaves 〉 immature seeds and glumes 〉 roots 〉 stems in different tissues of transgenic rice in grain-filling stage; Bt protein content of trans- genic rice changed a little in different growth stages (including tillering stage, booting stage, and grain-filling stage); in general, its level declined a little in later growth stage, but the resistibility would not be influenced significantly. [Conclusion] The ex- periment is significant for pest prevention and transgenic rice breeding.展开更多
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 et...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.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
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 immunog...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.展开更多
Chlamydial and gonococcal infections are recognized as two of the major causes of sexually transmissible human bacterial infection which may lead to infertility. In this cross sectional study, we aimed to determine th...Chlamydial and gonococcal infections are recognized as two of the major causes of sexually transmissible human bacterial infection which may lead to infertility. In this cross sectional study, we aimed to determine the prevalence of Neisseria gonorrhoeae, Chlamydia trachomatis among Egyptian women using different microbiological methods. One hundred and fifty cervical swabs were collected, of which 100 were from infertile women. Culture and ELISA technique were used for screening of Neisseria gonorrhoeae and Chlamydia trachomatis individually. In addition, PCR was used for all examined samples. For C. trachomatis, 3 cases were positive for antigen detection by ELISA. Moreover, in obtained results of PCR, DNA was detected in 4 samples, and three of them from infertile group. So based on PCR results, the sensitivity and specificity of ELISA were 75% and 100% respectively. Furthermore, 3 samples were positive for gonococcal infections by PCR, and two of them were taken from infertile women. Positive results of two samples were verified by culture. The estimated sensitivity and specificity of culture method were 66.7% and 100% respectively. Results of this study indicate that PCR is a valuable method for detection of gonococcal and chlamydial infection and it is suitable for the confirmation of ELISA results for C. trachomatis diagnosis. Culture method is less sensitive than PCR for detection of N. gonorrhoeae. The prevalence of such infections is higher among infertile women.展开更多
Hepatocellular carcinoma (HCC) is one of the most common malignancies in China. To date, surgery is still the best solution to it. However, metastatic recurrences after curative hepatic resections are very common. Tan...Hepatocellular carcinoma (HCC) is one of the most common malignancies in China. To date, surgery is still the best solution to it. However, metastatic recurrences after curative hepatic resections are very common. Tang et al have reported that recurrence rate within 5 years of curative hepatic resection is 61.5% [1]. As curative hepatic resection has a high tendency for metastatic recurrence, therapeutic interventions such as transarterial embolization and antiangiogenesis have been tried to further improve prognosis of HCC patients. Therefore, establishing a dependable, sensitive, easy, and economical method to predict metastatic recurrence following curative hepatic resection is of clinical urgency.展开更多
INTRODUCTIONVitamin E succinate (RRR-α-Tocopheryl Succinate,VES), a derivative of natural vitamin E, is acompound esterified by succinic acid and 6-hydroxyl-α-tocopheryl.
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.
基金Innovation and Entrepreneurship Project for College Students in Changsha Medical University,Changsha Medical Education 2022(Project No.41-149)。
文摘Objective:This investigation delineates the anti-cancer potency of epigallocatechin-3-gallate(EGCG)in an oral cancer mouse model,with a focus on its effect on T-cell activation.Methods:An oral cancer model was established in male Balb/c mice using 4-nitroquinoline 1-oxide(4-NQO).The mice were systematically grouped and administered graded concentrations of EGCG.Key parameters such as body weight,hydration levels,tumor volume,and mass were meticulously tracked.T-cell activity and cytokine expression profiles,focusing on interleukin-2(IL-2),interferon-gamma(IFN-γ),and tumor necrosis factor-alpha(TNF-α),were quantified using ELISA.A comprehensive statistical evaluation included one-way ANOVA,Tukey’s HSD multiple comparison test,and the Kruskal-Wallis non-parametric assessment.Results:EGCG-administered cohorts exhibited a pronounced reduction in tumor size and mass,with the high-dose group showing the greatest efficacy.ELISA findings corroborated a significant increase in T-cell activity and concomitant upregulation of key cytokines,including IL-2,IFN-γ,and TNF-α(P<0.05).Conclusion:This investigation confirms the tumor-suppressive efficacy of EGCG in a murine oral squamous cell carcinoma model.The therapeutic effects of EGCG are mediated through T-cell activation and the upregulation of pivotal cytokine expression,highlighting its potential immunomodulatory role in oral cancer treatment.
基金Supported by the German Federal Ministry of Education and Research(BMBF-Wachstumskern-PRAEMED.BIO),03WKDB2Csupported by the Janos Bolyai Research Scholarship of the Hungarian Academy of Sciences,BO/00232/17/5+1 种基金Research Grants of National Research Development and Innovation Office,K115818/2015/1New National Excellence Program of the Ministry of Human Capacities,ÚNKP-18-4 Bolyai Plus.
文摘BACKGROUND Defective neutrophil regulation in inflammatory bowel disease(IBD)is thought to play an important role in the onset or manifestation of IBD,as it could lead to damage of the intestinal mucosal barrier by the infiltration of neutrophils in the inflamed mucosa and the accumulation of pathogens.Like neutrophils in the context of innate immune responses,immunoglobulin A(IgA)as an acquired immune response partakes in the defense of the intestinal epithelium.Under normal conditions,IgA contributes to the elimination of microbes,but in connection with the loss of tolerance to chitinase 3-like 1(CHI3L1)in IBD,IgA could participate in CHI3L1-mediated improved adhesion and invasion of potentially pathogenic microorganisms.The tolerance brake to CHI3L1 and the occurrence of IgA autoantibodies to this particular target,the exact role and underlying mechanisms of CHI3L1 in the pathogenesis of IBD are still unclear.AIM To determine the predictive potential of Ig subtypes of a novel serological marker,anti-CHI3L1 autoantibodies(aCHI3L1)in determining the disease phenotype,therapeutic strategy and long-term disease course in a prospective referral cohort of adult IBD patients.METHODS Sera of 257 Crohn’s disease(CD)and 180 ulcerative colitis(UC)patients from a tertiary IBD referral center of Hungary(Division of Gastroenterology,Department of Internal Medicine,Faculty of Medicine,University of Debrecen)were assayed for IgG,IgA,and secretory IgA(sIgA)type aCHI3L1 by enzyme-linked immunosorbent assay using recombinant CHI3L1,along with 86 healthy controls(HCONT).RESULTS The IgA type was more prevalent in CD than in UC(29.2%vs 11.1%)or HCONT(2.83%;P<0.0001 for both).However,sIgA subtype aCHI3L1 positivity was higher in both CD and UC patients than in HCONT(39.3%and 32.8%vs 4.65%,respectively;P<0.0001).The presence of both IgA and sIgA aCHI3L1 antibodies was associated with colonic involvement(P<0.0001 and P=0.038,respectively)in patients with CD.Complicated disease behavior at sample procurement was associated with aCHI3L1 sIgA positivity(57.1%vs 36.0%,P=0.009).IgA type aCH3L1 was more prevalent in patients with frequent relapse during the disease course in the CD group(46.9%vs 25.7%,P=0.005).In a group of patients with concomitant presence of pure inflammatory luminal disease and colon involvement at the time of diagnosis,positivity for IgA or sIgA type aCH3L1 predicted faster progression towards a complicated disease course in time-dependent models.This association disappeared after merging subgroups of different disease locations.CONCLUSION CHI3L1 is a novel neutrophil autoantigenic target in IBD.The consideration of antibody classes along with location-based prediction may transform the future of serology in IBD.
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Transgenic cry1C Novel Materials of Japonica Rice Resistant Against Snout Moth’s Larva Cultivated with Biotechnology (201205068)The National Program of Transgenic Variety Development of China (2011ZX08001-001)~~
文摘[Objective] The aim of this study was to study on expression of Bt protein in transgenic pest-resistant rice. [Method] Enzyme-linked immunosorbent assay (ELISA) was used to measure Bt protein expression in different tissues of transgenic pest-resistant rice at same growth stage. [Result] Absolute content of Bt protein from high to low was as follows: leaves 〉 immature seeds and glumes 〉 roots 〉 stems in different tissues of transgenic rice in grain-filling stage; Bt protein content of trans- genic rice changed a little in different growth stages (including tillering stage, booting stage, and grain-filling stage); in general, its level declined a little in later growth stage, but the resistibility would not be influenced significantly. [Conclusion] The ex- periment is significant for pest prevention and transgenic rice breeding.
基金SupportedbytheNationalNaturalScienceFoundationofChina (No .39870 473) .
文摘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.
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.
文摘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.
文摘Chlamydial and gonococcal infections are recognized as two of the major causes of sexually transmissible human bacterial infection which may lead to infertility. In this cross sectional study, we aimed to determine the prevalence of Neisseria gonorrhoeae, Chlamydia trachomatis among Egyptian women using different microbiological methods. One hundred and fifty cervical swabs were collected, of which 100 were from infertile women. Culture and ELISA technique were used for screening of Neisseria gonorrhoeae and Chlamydia trachomatis individually. In addition, PCR was used for all examined samples. For C. trachomatis, 3 cases were positive for antigen detection by ELISA. Moreover, in obtained results of PCR, DNA was detected in 4 samples, and three of them from infertile group. So based on PCR results, the sensitivity and specificity of ELISA were 75% and 100% respectively. Furthermore, 3 samples were positive for gonococcal infections by PCR, and two of them were taken from infertile women. Positive results of two samples were verified by culture. The estimated sensitivity and specificity of culture method were 66.7% and 100% respectively. Results of this study indicate that PCR is a valuable method for detection of gonococcal and chlamydial infection and it is suitable for the confirmation of ELISA results for C. trachomatis diagnosis. Culture method is less sensitive than PCR for detection of N. gonorrhoeae. The prevalence of such infections is higher among infertile women.
基金the Shanghai Leading Medical Subjects Grant(№983001)State Key Basic Research Grant(№G1998051211)for financial supports.
文摘Hepatocellular carcinoma (HCC) is one of the most common malignancies in China. To date, surgery is still the best solution to it. However, metastatic recurrences after curative hepatic resections are very common. Tang et al have reported that recurrence rate within 5 years of curative hepatic resection is 61.5% [1]. As curative hepatic resection has a high tendency for metastatic recurrence, therapeutic interventions such as transarterial embolization and antiangiogenesis have been tried to further improve prognosis of HCC patients. Therefore, establishing a dependable, sensitive, easy, and economical method to predict metastatic recurrence following curative hepatic resection is of clinical urgency.
基金Project supported by National Natural Science Foundation of China, No. 39870662
文摘INTRODUCTIONVitamin E succinate (RRR-α-Tocopheryl Succinate,VES), a derivative of natural vitamin E, is acompound esterified by succinic acid and 6-hydroxyl-α-tocopheryl.