Atrazine（AT,2-chloro-4-ethylamino-6-isopropyl-amino-s-triazine）has been detected in ground water in several areas of the United States for many years,as well as in China,wherein the growth rate of its gross
Mycoplasma mycoides subsp mycoides SC （MmmSC） is the etiological agent of contagious bovine pleuropneumonia （CBPP）. The lipoprotein LppQ encoded by lppQ gene is specific to MmmSC and is found in the type strain an...Mycoplasma mycoides subsp mycoides SC （MmmSC） is the etiological agent of contagious bovine pleuropneumonia （CBPP）. The lipoprotein LppQ encoded by lppQ gene is specific to MmmSC and is found in the type strain and in field strains isolated in Europe, Africa, and Australia, as well as in vaccine strains. No serological cross-reactions were observed with the related mycoplasmas of the Mycoplasma mycoides cluster. The N-terminal domain of the mature lipoprotein LppQ is hydrophilic, and it induces a strong, specific, early, and persistent immune response in naturally and experimentally infected animals. Mycoplasma-specific TGA （Trp） codons are utilized as stop codons in most other organisms. The lppQ N-terminal fragment from MmmSC HVRI X strain, the Chinese strain for CF antigen production, was mutated with one-step overlapping extension PCR. Sequence analysis confirmed the successful mutation from A to G in codon 198 in the lppQ gene. The fragment containing the mutation site was subcloned into the pET32a expression vector. The recombinant protein with molecular weight of 42 kDa was purified using the Ni-NTA His.Bind purification kit, with a purity of up to 95%. Western blot indicated that the standard positive serum of CBPP could react with the recombinant protein. The purified protein was diluted to 0.35 μg mL^-1, and coated to microtiter enzyme-linked immunosorbent assay （ELISA） plates. Indirect ELISA reaction conditions were optimized. The value of P/N was determined to be 4.8 （0.934/0.193）, the sensitivity to be 95.8% （46/48）, and the specificity to be 98.9% （161/163）. 3 817 cattle serum samples from three different provinces were detected by the indirect ELISA and CFT. The Kappa value is 0.63, which is middle or high agreement between the two methods.展开更多
Enzyme-linked immunosorbent assay (ELISA) is the most widely used method for measuring a single cytokine. Recent developments in cytokine quantification such as multiple arrays measure multiple cytokines simultaneousl...Enzyme-linked immunosorbent assay (ELISA) is the most widely used method for measuring a single cytokine. Recent developments in cytokine quantification such as multiple arrays measure multiple cytokines simultaneously. Although good correlations between ELISA and multiplex methods have been observed, side by side comparisons are limited. In the present study we hypothesized that ELISA and Luminex techniques are comparable in detecting cytokines in culture medium when pulmonary artery smooth muscle cells (PASMC) are exposed to stress. Primary human PASMC were cultured in modular chambers and exposed to 21% FiO2 and peak inspiratory and positive end expiratory pressure of 24 and 8 cmH2O respectively, and 95% FiO2. At 24 hours, culture medium was collected and assayed for interleukin-6 (IL-6) and IL-8 by quantitative ELISA and by Human Cytokine 25-Plex Panel using a Luminex 200 analyzer. A comparative analysis of agreement between our ELISA and Luminex data was detailed for control and stress conditions using the Bland-Altman plot analysis. Each assay resulted in comparable increased (p < 0.001) levels of IL-6 and IL-8 as compared to control in response to oxidative and biophysical stress. The Bland-Altman analysis demonstrated that 95% of the differences between ELISA and Luminex values were within ±1.96 SD from the mean difference indicated by the 95% limits of agreement for the measurements of IL-6 and IL-8. There was no systematic bias as a function of inflammation level. We conclude that in this cell culture model, ELISA and Luminex are comparable in detecting the levels of IL-6 and IL-8 in the culture medium. If measurements of multiple cytokines are demanded and the amount of sample is limited, Luminex multi-analyte profiling technology is accurate and sensitive.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
Objective： Survivin as a tumor marker in the diagnosis of bladder cancer has not been completely confirmed yet and there are few reports about using Survivin enzyme-linked immunosorbent assay （ELISA） kit to detect ...Objective： Survivin as a tumor marker in the diagnosis of bladder cancer has not been completely confirmed yet and there are few reports about using Survivin enzyme-linked immunosorbent assay （ELISA） kit to detect the urine of bladder cancer patients. This study aimed to develop a Survivin ELISA and validate its value in the detection of bladder cancer. Methods： Through square matrix titration, different combinations of coating antibody and detecting antibody, a Survivin ELISA was constructed. This assay was evaluated according to intra-assay precision, inter-assay precision and minimum detectable dose （MDD）. Survivin levels were detected and analyzed in 102 bladder cancer patients and 102 healthy people by established ELISA. Then cutoff value was defined according to the analysis of receiver operating characteristic （ROC） curve. The sensitivity and specificity of detection were calculated on the basis of cutoff value to diagnose bladder cancer patients. Furthermore, the value of Survivin expression detected by ELISA among different clinicopathological characteristics of patients was also compared. Results： Through optimization of different conditions, intra-assay precision was 8.39%, inter-assay precision 8.57% and MDD 0.0625 ng/mL in this assay. When the optical density at 450 nm （OD 450 ） was 0.09, it could get the optimized diagnostic cutoff value. According to this value, the sensitivity and specificity of diagnosis in bladder cancer patients were 70.6% and 89.2%, respectively. The associations between patients＇ clinical variables and OD 450 were not significant except tumor numbers in patients. Conclusions： This experiment has preliminarily developed a Survivin ELISA and confirmed Survivin as a biomarker which owned a practical and significant value in the diagnosis of bladder cancer.展开更多
Plasma quinolone concentrations are not routinely measured in clinical practice.However,in order to optimize quinolone treatment,monitoring of plasma concentrations could sometimes be useful particularly in critically...Plasma quinolone concentrations are not routinely measured in clinical practice.However,in order to optimize quinolone treatment,monitoring of plasma concentrations could sometimes be useful particularly in critically ill patients.In this study,anti-sparfloxacin antibody was obtained by immunizing rabbits with sparfloxacin conjugated with bovine serum albumin using isobutyl chloroformate method.After the assay procedure was optimized,the standard curve of sparfloxacin was established.The practical measuring range of the competitive ELISA extended from 5 ng/mL to 2 mg/mL.The recovery rates and coefficients of variation for rat plasma,urine and tissues were 87.7-106.2% and 4.8-15.3%,respectively.To demonstrate the potential of the ELISA,a preliminary pharmacokinetics and tissue distribution study of sparfloxacin in rats and quantitative analysis of sparfloxacin in several pharmaceuticals were performed and compared with high-performance liquid chromatography(HPLC).The experimental data indicated that the proposed method would be a valuable tool in therapeutic drug monitoring(TDM) for sparfloxacin.展开更多
Objective:To develop a standard enzyme-linked immunosorbent assay（ELJSA） for the detection of bovine herpesvirus type 1（BHV-1）.Methods:The assay was based on hyperimmune rabbit and guinea pig antisera raised again...Objective:To develop a standard enzyme-linked immunosorbent assay（ELJSA） for the detection of bovine herpesvirus type 1（BHV-1）.Methods:The assay was based on hyperimmune rabbit and guinea pig antisera raised against purified BHV-1.Polyethylene glycol precipitation and sucrose density gradient methods were adopted for viral concentration and purification.Antisera were raised using Freund’s adjuvant followed by extraction of IgG of high purity.Results: Optimum antisera dilutions as determined by titrations were chosen as 14 000,whereas the conjugate was used at 1:2 000 dilution.Using 95 clinical specimens,the ELISA test showed a sensitivity and specificity of 91.90%and 93.10%,respectively when compared to PCR.The cutoff value was fixed at 0.15<sub>490</sub>) and a P/N ratio of】1.30 indicated a significant positive reaction. Conclusions:The results have demonstrated that this ELISA could efficiently detect BHV-1 and can be used as an important diagnostic tool.展开更多
The simple rapid and sensitive enzyme-linked immunosorbent assay (ELISA) methods, di-rect and indirect ELISA, for quantitation of ochratoxin A in cereal had been developed by theutilization of monoclonal antibody on i...The simple rapid and sensitive enzyme-linked immunosorbent assay (ELISA) methods, di-rect and indirect ELISA, for quantitation of ochratoxin A in cereal had been developed by theutilization of monoclonal antibody on immunomicroplate. Direct FLIAS was found to be less timeconsuming than indirect ELISA. For direct FLISA, recovery of 1 -500 ppb OA added to wheat was78.9-100.0% and rice was 88.9- 120.0%. For indirect EI.IAS, recovery of 1-500 ppb OA addedto wheat was 79.0- 110.0% and rice was 82.0 120.0%. The minimal detection level for OA was Ippb. Analyses of 31 samples that caused humanintoxicant for OA showed that the ELISA resultsagreed wtll with those obtained by thin-layer chromatogrdphy.展开更多
Microcystins(MCs)are a group of closely related toxic cyclic heptapeptides produced by common cyanobacte-ria,which cause lots of accidents and threatens human health.In this paper,an indirect competitive enzyme-linked...Microcystins(MCs)are a group of closely related toxic cyclic heptapeptides produced by common cyanobacte-ria,which cause lots of accidents and threatens human health.In this paper,an indirect competitive enzyme-linked immu-nosorbent assay(ic-ELISA)was established and used to detect microcystin-LR(MC-LR)in drinking and surface waters.The concentration of coating antigen was 5 mg/mL,the dilution of monoclonal antibody MC10E7 was 1:3000,the dilution of enzyme tracer(goat anti-mouse IgG-peroxidase)was 1:3000,the standard concentration of MC-LR ranged from 0.001 mg/L to 30 mg/L,and o-phenylenediamine was used as substrate.The assay showed high relativity with high performance liquid chromatography(HPLC)with a correlation coefficient of more than 99%.The relative standard deviation was less than 10%,the detection limit was achieved down to 0.01 mg/L and up to 5.1 mg/L.The quantitative detection range was from 0.03 mg/L to 3 mg/L,and the antibody had high specificity for[4-arginine]microcystins.It performed well in spite of the influence of the real samples.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
A protein conjugate of streptomycin （streptomycin-bovine serum albumin （BSA） conjugate） was prepared and used as immunogen to produce monoclonal antibodies （MAb）. One hybridoma secreting anti-streptomycin MAb wa...A protein conjugate of streptomycin （streptomycin-bovine serum albumin （BSA） conjugate） was prepared and used as immunogen to produce monoclonal antibodies （MAb）. One hybridoma secreting anti-streptomycin MAb was obtained and then used to produce MAb. The MAb named 13H5 showed the 50% maximal inhibitory concentra- tion （IC50） value of 4.65 ng/ml and the IC20value of 0.21 ng/ml in phosphate buffered saline （PBS）. At optimum con- ditions, an indirect competitive enzyme-linked immunosorbent assay （ELISA） and a colloidal gold-based immuno- chromatographic assay （CGIA） were developed and applied to detect streptomycin residues in milk and swine urine samples. The developed ELISA showed that the minimum detection limit was 2.0 and 1.9 ng/ml for milk and swine urine samples, respectively, without obvious cross-reactivity to other tested antibiotics except dihydrostreptomycin which gave a 118.32% cross reaction value. Milk and swine urine samples spiked with streptomycin at 10, 50, 100 and 200 ng/rnl were analyzed by the established ELISA. The mean recovery of streptomycin was from 81.9% to 105.5% and from 84.3% to 92.2% for milk and swine urine, respectively. The optimized CGIA showed that the minimum de- tection limit was 20.0 ng/ml for milk and swine urine samples. The results of spiked analysis and specific analysis demonstrate that the CGIA could be applicable for screening milk and swine urine samples for the presence of streptomycin residues on-site. The established ELISA and CGIA allow the rapid, low-cost, and sensitive determination of streptomycin residues in food samples.展开更多
Objective：The programmed cell death-1 receptor/programmed cell death-1 ligand （PD-1/PD-L1） pathway plays a crucial role in tumor evasion from host immunity.This study was designed to evaluate the association betwee...Objective：The programmed cell death-1 receptor/programmed cell death-1 ligand （PD-1/PD-L1） pathway plays a crucial role in tumor evasion from host immunity.This study was designed to evaluate the association between circulating PD-L1 expression and prognosis in patients with advanced gastric cancer.Methods：Totally 80 advanced gastric cancer patients and 40 health controls from Beijing Cancer Hospital were enrolled in the present study.Circulating PD-L1 expression was tested by enzymelinked immunosorbent assay （ELISA）.The associations between the expression level of PD-L1 and clinicopathological features and prognosis were analyzed statistically.Results：Expression of PD-L1 in advanced gastric cancer patients was significandy up-regulated compared with health people （P=0.006）.The expression of PD-L1 was significantly correlated with differentiation and lymph node metastasis （P=0.026 and P=0.041,respectively）.Although we didn＇t find significant difference in all advanced gastric cancer patients with different PD-L1 expression,the adenocarcinoma patients with higher up-regulated PD-L1 expression had much better prognosis than low expression patients （65.6％ vs.44.7％,P=0.028）.Conclusions：PD-L1 was elevated in advance gastric cancer patients and may play an important role in tumor immune evasion and patients prognosis.展开更多
Ebola virus(EBOV) and Marburg virus(MARV),belonging to the Filoviridae family,emerged four decades ago and caused severe viral hemorrhagic fever in human and other primates.As high as 50-90% mortality,filoviruses can ...Ebola virus(EBOV) and Marburg virus(MARV),belonging to the Filoviridae family,emerged four decades ago and caused severe viral hemorrhagic fever in human and other primates.As high as 50-90% mortality,filoviruses can cause significant threats to public health.However,so far no specific and efficient vaccine has been available,nor have other treatment methods proved to be effective.It is of great importance to detect these pathogens specific,rapidly and sensitively in order to control future filovirus outbreaks.Here,recent progresses in the development of detection and diagnosis methods for EBOV and MARV are summarized.展开更多
Rice ragged stunt virus（RRSV） is a serious rice disease in Asia, causing serious yield losses on rice. The capsid protein（CP） gene of the major outer capsid protein of RRSV was expressed in Escherichia coli BL21（...Rice ragged stunt virus（RRSV） is a serious rice disease in Asia, causing serious yield losses on rice. The capsid protein（CP） gene of the major outer capsid protein of RRSV was expressed in Escherichia coli BL21（DE3） using the pMAL-C2 X expression vector. The recombinant protein was used as the immunogen to immunize BALB/c mice. A hybridoma cell line 8A12 secreting monoclonal antibody（MAb） against RRSV was obtained by fusing mouse myeloma cells（Sp 2/0） with spleen cells from the immunized BALB/c mice. Western blot analysis showed that the MAb 8A12 can specifically react with RRSV CP. Using the MAb, an antigen-coated-plate enzyme-linked immunosorbent assay（ACP-ELISA）, a dot enzyme-linked immunosorbent assay（dot-ELISA）, and immunocapture-RT-PCR（IC-RT-PCR） assay were developed to detect RRSV. The established ACP-ELISA, dot-blot ELISA and IC-RT-PCR methods could detect RRSV in infected rice tissue crude extracts with dilutions of 1：40 960, 1：1 280 and 1：655 360（w/v, g mL-1）, respectively. The ACP-ELISA and dot-blot ELISA methods could detect RRSV in infected insect vector crude extracts with dilutions of 1：12 800 and 1：1 600（an individual planthopper μL-1）, respectively. The field survey revealed that Rice ragged stunt disease occurs on rice in Hainan, Yunnan, Guangxi, Sichuan, Guizhou, Fujian, Hunan, Jiangxi and Zhejiang in China.展开更多
A competitive enzyme-linked immunosorbent assay （ELISA） suitable for the determination of the urea herbicide isoproturon, 3-（4-isopropylphenyl）-l,l-dimethylurea, in food and environmental samples was developed. Tw...A competitive enzyme-linked immunosorbent assay （ELISA） suitable for the determination of the urea herbicide isoproturon, 3-（4-isopropylphenyl）-l,l-dimethylurea, in food and environmental samples was developed. Two haptens named 1-（3- carboxypropyl）-3-（4-isopropylphenyl）-1-methylurea （hapten 4C） and 1-（5-carboxypentyl）-3-（4-isopropylphenyl）-1- methylurea （hapten 6C） were synthesized. The haptens were coupled to bovine serum albumin （BSA） and ovalbumin （OVA）, respectively, using the N-hydroxysuccinimide reaction. The hapten 6C-BSA conjugate was used as the immunogen, with which a high-titer anti-isoproturon polyclonal antibody （pAb） was successfully obtained by immunization of New Zealand white rabbits. The hapten 4C-OVA conjugate was used as coating antigen and a method of the indirect competitive ELISA for isoproturon was established. The haptens were confirmed with TLC, IR, and 1H NMR. The conjugation molar ratios of hapten 4C to OVA and hapten 6C to BSA were 36：1 and 46：1, respectively, as calculated by a UV spectrophotometry. The highest titer of the anti-isoproturon sera determined by a non-competitive indirect ELISA procedure was 1.6 × 10^5. The optimal concentrations of the coating antigen and the dilution of the anti-isoproturon sera used in the ELISA were 0.1 mg·L^-1 and 1.0 × 10^5, respectively. The concentration of isoproturon that inhibits 50% of antibody-antigen binding （IC50） was 0.07 mg·mL^-1. The cross-reactivities of six urea herbicides including chlorbromuron, fluometuron, monolinuron were lower than 0.1%. Isoproturon is a small molecule without immune activity and active functional group for attaching to carrier protein. To produce an antibody against isoproturon with high titer and high specificity is the most important step in the development of an immunochemical method for the determination of isoproturon in food and environmental samples. The two haptens synthesized in this study have carboxyl groups and accommodate different lengths of spacer arms, and the phenyl and isopropyl groups are fully exposed. An anti-isoproturon polyclonal antibody with high titer and high specificity was successfully obtained by immunization of rabbits with the conjugate of the hapten attached to the protein carrier.展开更多
The identification and localization of vertebrate follicle stimulating hormone （FSH） and luteinizing hormone （LH） in crustaceans may further elucidate the regulation mechanisms in arthropod repro-duction. Using im...The identification and localization of vertebrate follicle stimulating hormone （FSH） and luteinizing hormone （LH） in crustaceans may further elucidate the regulation mechanisms in arthropod repro-duction. Using immunocytochemical staining techniques, this study has localized vertebrate FSH-like and LH-like substances in neurons in the subesophageal and thoracic ganglia from the thoracic ganglion mass （TGM） of Scylla paramamosain （Crustacea： Decapoda： Brachyura）. Enzyme-linked immunosorbent assay （ELISA） has shown that the concentrations of both FSH-and LH-like sub-stances increased markedly in the TGM during the vitellogenic stage compared with that in the previtellogenic stage. These results indicate that substances resembling the vertebrate FSH and LH are present in S. paramamosain, and they may be involved in the development of the ovary as well as in ovulation.展开更多
Diethylphosphono acetic acid （DPA） was used as a current hapten to generate broad specificity polycolonal antibodies against a group of organophosphorus pesticides. Six New Zealand white rabbits were immunized with ...Diethylphosphono acetic acid （DPA） was used as a current hapten to generate broad specificity polycolonal antibodies against a group of organophosphorus pesticides. Six New Zealand white rabbits were immunized with immunogens synthesized by the active ester method （AEM） or 1-ethyl-3-（3-dimethylaminopropyl）-carbodimide method （EDC）. The titers of antisera reached 25 600 by AEM and 6 400 by EDC, respectively. Polyclonal antibodies raised against DPA were screened and selected for the competitive indirect enzyme-linked immunosorbent assay （CI-ELISA）. A CI-ELISA for DPA was developed with a detection limit of 3.536 ng mL^-1and an I50 value of 0.182 μg mL^-1. The assay specificity was evaluated by obtaining competitive curves for several structurally related compounds as competitors. The antiserum showed high affinities to chlorpyrifos, diazinon, omethoate, parathion-ethyl and profenofos with I50 of 0.12, 0.15, 0.21, 0.88, 0.97 and 2.5 μg mL^-1, respectively. The results indicate that the assay could be a screening tool for quantitation and semiquantitation determination of the above former five organophosphorus pesticides.展开更多
基金supported by the National Natural Science Foundation of China(No.81030052,20907074)National Science & Technology Supporting Program(2012BAJ25B03-02)Tianjin Science & Technology Program(11ZCKFSF01100)
文摘Atrazine（AT,2-chloro-4-ethylamino-6-isopropyl-amino-s-triazine）has been detected in ground water in several areas of the United States for many years,as well as in China,wherein the growth rate of its gross
文摘Mycoplasma mycoides subsp mycoides SC （MmmSC） is the etiological agent of contagious bovine pleuropneumonia （CBPP）. The lipoprotein LppQ encoded by lppQ gene is specific to MmmSC and is found in the type strain and in field strains isolated in Europe, Africa, and Australia, as well as in vaccine strains. No serological cross-reactions were observed with the related mycoplasmas of the Mycoplasma mycoides cluster. The N-terminal domain of the mature lipoprotein LppQ is hydrophilic, and it induces a strong, specific, early, and persistent immune response in naturally and experimentally infected animals. Mycoplasma-specific TGA （Trp） codons are utilized as stop codons in most other organisms. The lppQ N-terminal fragment from MmmSC HVRI X strain, the Chinese strain for CF antigen production, was mutated with one-step overlapping extension PCR. Sequence analysis confirmed the successful mutation from A to G in codon 198 in the lppQ gene. The fragment containing the mutation site was subcloned into the pET32a expression vector. The recombinant protein with molecular weight of 42 kDa was purified using the Ni-NTA His.Bind purification kit, with a purity of up to 95%. Western blot indicated that the standard positive serum of CBPP could react with the recombinant protein. The purified protein was diluted to 0.35 μg mL^-1, and coated to microtiter enzyme-linked immunosorbent assay （ELISA） plates. Indirect ELISA reaction conditions were optimized. The value of P/N was determined to be 4.8 （0.934/0.193）, the sensitivity to be 95.8% （46/48）, and the specificity to be 98.9% （161/163）. 3 817 cattle serum samples from three different provinces were detected by the indirect ELISA and CFT. The Kappa value is 0.63, which is middle or high agreement between the two methods.
文摘Enzyme-linked immunosorbent assay (ELISA) is the most widely used method for measuring a single cytokine. Recent developments in cytokine quantification such as multiple arrays measure multiple cytokines simultaneously. Although good correlations between ELISA and multiplex methods have been observed, side by side comparisons are limited. In the present study we hypothesized that ELISA and Luminex techniques are comparable in detecting cytokines in culture medium when pulmonary artery smooth muscle cells (PASMC) are exposed to stress. Primary human PASMC were cultured in modular chambers and exposed to 21% FiO2 and peak inspiratory and positive end expiratory pressure of 24 and 8 cmH2O respectively, and 95% FiO2. At 24 hours, culture medium was collected and assayed for interleukin-6 (IL-6) and IL-8 by quantitative ELISA and by Human Cytokine 25-Plex Panel using a Luminex 200 analyzer. A comparative analysis of agreement between our ELISA and Luminex data was detailed for control and stress conditions using the Bland-Altman plot analysis. Each assay resulted in comparable increased (p < 0.001) levels of IL-6 and IL-8 as compared to control in response to oxidative and biophysical stress. The Bland-Altman analysis demonstrated that 95% of the differences between ELISA and Luminex values were within ±1.96 SD from the mean difference indicated by the 95% limits of agreement for the measurements of IL-6 and IL-8. There was no systematic bias as a function of inflammation level. We conclude that in this cell culture model, ELISA and Luminex are comparable in detecting the levels of IL-6 and IL-8 in the culture medium. If measurements of multiple cytokines are demanded and the amount of sample is limited, Luminex multi-analyte profiling technology is accurate and sensitive.
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 National High Technology Research Development Plan (No.2012AA02A504)the Capital Healthy Development Special Fund (No.2011-1009-03)the Capital Laboratory Medicine Clinical Characteristic Fund (No.Z121107005112004)
文摘Objective： Survivin as a tumor marker in the diagnosis of bladder cancer has not been completely confirmed yet and there are few reports about using Survivin enzyme-linked immunosorbent assay （ELISA） kit to detect the urine of bladder cancer patients. This study aimed to develop a Survivin ELISA and validate its value in the detection of bladder cancer. Methods： Through square matrix titration, different combinations of coating antibody and detecting antibody, a Survivin ELISA was constructed. This assay was evaluated according to intra-assay precision, inter-assay precision and minimum detectable dose （MDD）. Survivin levels were detected and analyzed in 102 bladder cancer patients and 102 healthy people by established ELISA. Then cutoff value was defined according to the analysis of receiver operating characteristic （ROC） curve. The sensitivity and specificity of detection were calculated on the basis of cutoff value to diagnose bladder cancer patients. Furthermore, the value of Survivin expression detected by ELISA among different clinicopathological characteristics of patients was also compared. Results： Through optimization of different conditions, intra-assay precision was 8.39%, inter-assay precision 8.57% and MDD 0.0625 ng/mL in this assay. When the optical density at 450 nm （OD 450 ） was 0.09, it could get the optimized diagnostic cutoff value. According to this value, the sensitivity and specificity of diagnosis in bladder cancer patients were 70.6% and 89.2%, respectively. The associations between patients＇ clinical variables and OD 450 were not significant except tumor numbers in patients. Conclusions： This experiment has preliminarily developed a Survivin ELISA and confirmed Survivin as a biomarker which owned a practical and significant value in the diagnosis of bladder cancer.
文摘Plasma quinolone concentrations are not routinely measured in clinical practice.However,in order to optimize quinolone treatment,monitoring of plasma concentrations could sometimes be useful particularly in critically ill patients.In this study,anti-sparfloxacin antibody was obtained by immunizing rabbits with sparfloxacin conjugated with bovine serum albumin using isobutyl chloroformate method.After the assay procedure was optimized,the standard curve of sparfloxacin was established.The practical measuring range of the competitive ELISA extended from 5 ng/mL to 2 mg/mL.The recovery rates and coefficients of variation for rat plasma,urine and tissues were 87.7-106.2% and 4.8-15.3%,respectively.To demonstrate the potential of the ELISA,a preliminary pharmacokinetics and tissue distribution study of sparfloxacin in rats and quantitative analysis of sparfloxacin in several pharmaceuticals were performed and compared with high-performance liquid chromatography(HPLC).The experimental data indicated that the proposed method would be a valuable tool in therapeutic drug monitoring(TDM) for sparfloxacin.
文摘Objective:To develop a standard enzyme-linked immunosorbent assay（ELJSA） for the detection of bovine herpesvirus type 1（BHV-1）.Methods:The assay was based on hyperimmune rabbit and guinea pig antisera raised against purified BHV-1.Polyethylene glycol precipitation and sucrose density gradient methods were adopted for viral concentration and purification.Antisera were raised using Freund’s adjuvant followed by extraction of IgG of high purity.Results: Optimum antisera dilutions as determined by titrations were chosen as 14 000,whereas the conjugate was used at 1:2 000 dilution.Using 95 clinical specimens,the ELISA test showed a sensitivity and specificity of 91.90%and 93.10%,respectively when compared to PCR.The cutoff value was fixed at 0.15<sub>490</sub>) and a P/N ratio of】1.30 indicated a significant positive reaction. Conclusions:The results have demonstrated that this ELISA could efficiently detect BHV-1 and can be used as an important diagnostic tool.
文摘The simple rapid and sensitive enzyme-linked immunosorbent assay (ELISA) methods, di-rect and indirect ELISA, for quantitation of ochratoxin A in cereal had been developed by theutilization of monoclonal antibody on immunomicroplate. Direct FLIAS was found to be less timeconsuming than indirect ELISA. For direct FLISA, recovery of 1 -500 ppb OA added to wheat was78.9-100.0% and rice was 88.9- 120.0%. For indirect EI.IAS, recovery of 1-500 ppb OA addedto wheat was 79.0- 110.0% and rice was 82.0 120.0%. The minimal detection level for OA was Ippb. Analyses of 31 samples that caused humanintoxicant for OA showed that the ELISA resultsagreed wtll with those obtained by thin-layer chromatogrdphy.
基金This work was supported by the National High-Tech Research and Development(863)Program of China(2002AA649160).
文摘Microcystins(MCs)are a group of closely related toxic cyclic heptapeptides produced by common cyanobacte-ria,which cause lots of accidents and threatens human health.In this paper,an indirect competitive enzyme-linked immu-nosorbent assay(ic-ELISA)was established and used to detect microcystin-LR(MC-LR)in drinking and surface waters.The concentration of coating antigen was 5 mg/mL,the dilution of monoclonal antibody MC10E7 was 1:3000,the dilution of enzyme tracer(goat anti-mouse IgG-peroxidase)was 1:3000,the standard concentration of MC-LR ranged from 0.001 mg/L to 30 mg/L,and o-phenylenediamine was used as substrate.The assay showed high relativity with high performance liquid chromatography(HPLC)with a correlation coefficient of more than 99%.The relative standard deviation was less than 10%,the detection limit was achieved down to 0.01 mg/L and up to 5.1 mg/L.The quantitative detection range was from 0.03 mg/L to 3 mg/L,and the antibody had high specificity for[4-arginine]microcystins.It performed well in spite of the influence of the real samples.
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Project (No.2007C22047) supported by the Program of Science and Technology of Zhejiang Province,China
文摘A protein conjugate of streptomycin （streptomycin-bovine serum albumin （BSA） conjugate） was prepared and used as immunogen to produce monoclonal antibodies （MAb）. One hybridoma secreting anti-streptomycin MAb was obtained and then used to produce MAb. The MAb named 13H5 showed the 50% maximal inhibitory concentra- tion （IC50） value of 4.65 ng/ml and the IC20value of 0.21 ng/ml in phosphate buffered saline （PBS）. At optimum con- ditions, an indirect competitive enzyme-linked immunosorbent assay （ELISA） and a colloidal gold-based immuno- chromatographic assay （CGIA） were developed and applied to detect streptomycin residues in milk and swine urine samples. The developed ELISA showed that the minimum detection limit was 2.0 and 1.9 ng/ml for milk and swine urine samples, respectively, without obvious cross-reactivity to other tested antibiotics except dihydrostreptomycin which gave a 118.32% cross reaction value. Milk and swine urine samples spiked with streptomycin at 10, 50, 100 and 200 ng/rnl were analyzed by the established ELISA. The mean recovery of streptomycin was from 81.9% to 105.5% and from 84.3% to 92.2% for milk and swine urine, respectively. The optimized CGIA showed that the minimum de- tection limit was 20.0 ng/ml for milk and swine urine samples. The results of spiked analysis and specific analysis demonstrate that the CGIA could be applicable for screening milk and swine urine samples for the presence of streptomycin residues on-site. The established ELISA and CGIA allow the rapid, low-cost, and sensitive determination of streptomycin residues in food samples.
文摘Objective：The programmed cell death-1 receptor/programmed cell death-1 ligand （PD-1/PD-L1） pathway plays a crucial role in tumor evasion from host immunity.This study was designed to evaluate the association between circulating PD-L1 expression and prognosis in patients with advanced gastric cancer.Methods：Totally 80 advanced gastric cancer patients and 40 health controls from Beijing Cancer Hospital were enrolled in the present study.Circulating PD-L1 expression was tested by enzymelinked immunosorbent assay （ELISA）.The associations between the expression level of PD-L1 and clinicopathological features and prognosis were analyzed statistically.Results：Expression of PD-L1 in advanced gastric cancer patients was significandy up-regulated compared with health people （P=0.006）.The expression of PD-L1 was significantly correlated with differentiation and lymph node metastasis （P=0.026 and P=0.041,respectively）.Although we didn＇t find significant difference in all advanced gastric cancer patients with different PD-L1 expression,the adenocarcinoma patients with higher up-regulated PD-L1 expression had much better prognosis than low expression patients （65.6％ vs.44.7％,P=0.028）.Conclusions：PD-L1 was elevated in advance gastric cancer patients and may play an important role in tumor immune evasion and patients prognosis.
文摘Ebola virus(EBOV) and Marburg virus(MARV),belonging to the Filoviridae family,emerged four decades ago and caused severe viral hemorrhagic fever in human and other primates.As high as 50-90% mortality,filoviruses can cause significant threats to public health.However,so far no specific and efficient vaccine has been available,nor have other treatment methods proved to be effective.It is of great importance to detect these pathogens specific,rapidly and sensitively in order to control future filovirus outbreaks.Here,recent progresses in the development of detection and diagnosis methods for EBOV and MARV are summarized.
基金supported by the National Basic Research Program of China(2010CB126203)the special fund for Agro-scientific Research in the Public Interest,China(201003031)+1 种基金Earmarked Funds for Modern Agro-industry Technology Research SystemZhejiang Provincial Natural Science Foundation of China(Z3090039)
文摘Rice ragged stunt virus（RRSV） is a serious rice disease in Asia, causing serious yield losses on rice. The capsid protein（CP） gene of the major outer capsid protein of RRSV was expressed in Escherichia coli BL21（DE3） using the pMAL-C2 X expression vector. The recombinant protein was used as the immunogen to immunize BALB/c mice. A hybridoma cell line 8A12 secreting monoclonal antibody（MAb） against RRSV was obtained by fusing mouse myeloma cells（Sp 2/0） with spleen cells from the immunized BALB/c mice. Western blot analysis showed that the MAb 8A12 can specifically react with RRSV CP. Using the MAb, an antigen-coated-plate enzyme-linked immunosorbent assay（ACP-ELISA）, a dot enzyme-linked immunosorbent assay（dot-ELISA）, and immunocapture-RT-PCR（IC-RT-PCR） assay were developed to detect RRSV. The established ACP-ELISA, dot-blot ELISA and IC-RT-PCR methods could detect RRSV in infected rice tissue crude extracts with dilutions of 1：40 960, 1：1 280 and 1：655 360（w/v, g mL-1）, respectively. The ACP-ELISA and dot-blot ELISA methods could detect RRSV in infected insect vector crude extracts with dilutions of 1：12 800 and 1：1 600（an individual planthopper μL-1）, respectively. The field survey revealed that Rice ragged stunt disease occurs on rice in Hainan, Yunnan, Guangxi, Sichuan, Guizhou, Fujian, Hunan, Jiangxi and Zhejiang in China.
基金This work was financially supported by National Natural Science Foundation of China （20447003）.
文摘A competitive enzyme-linked immunosorbent assay （ELISA） suitable for the determination of the urea herbicide isoproturon, 3-（4-isopropylphenyl）-l,l-dimethylurea, in food and environmental samples was developed. Two haptens named 1-（3- carboxypropyl）-3-（4-isopropylphenyl）-1-methylurea （hapten 4C） and 1-（5-carboxypentyl）-3-（4-isopropylphenyl）-1- methylurea （hapten 6C） were synthesized. The haptens were coupled to bovine serum albumin （BSA） and ovalbumin （OVA）, respectively, using the N-hydroxysuccinimide reaction. The hapten 6C-BSA conjugate was used as the immunogen, with which a high-titer anti-isoproturon polyclonal antibody （pAb） was successfully obtained by immunization of New Zealand white rabbits. The hapten 4C-OVA conjugate was used as coating antigen and a method of the indirect competitive ELISA for isoproturon was established. The haptens were confirmed with TLC, IR, and 1H NMR. The conjugation molar ratios of hapten 4C to OVA and hapten 6C to BSA were 36：1 and 46：1, respectively, as calculated by a UV spectrophotometry. The highest titer of the anti-isoproturon sera determined by a non-competitive indirect ELISA procedure was 1.6 × 10^5. The optimal concentrations of the coating antigen and the dilution of the anti-isoproturon sera used in the ELISA were 0.1 mg·L^-1 and 1.0 × 10^5, respectively. The concentration of isoproturon that inhibits 50% of antibody-antigen binding （IC50） was 0.07 mg·mL^-1. The cross-reactivities of six urea herbicides including chlorbromuron, fluometuron, monolinuron were lower than 0.1%. Isoproturon is a small molecule without immune activity and active functional group for attaching to carrier protein. To produce an antibody against isoproturon with high titer and high specificity is the most important step in the development of an immunochemical method for the determination of isoproturon in food and environmental samples. The two haptens synthesized in this study have carboxyl groups and accommodate different lengths of spacer arms, and the phenyl and isopropyl groups are fully exposed. An anti-isoproturon polyclonal antibody with high titer and high specificity was successfully obtained by immunization of rabbits with the conjugate of the hapten attached to the protein carrier.
基金The National Natural Science Foundation of China under contract Nos 40406030 and 40776084the National High Technology Research and Development Program of China under contract No 2006AA10A406the Program for New Century Excellent Talents in Fujian Province University
文摘The identification and localization of vertebrate follicle stimulating hormone （FSH） and luteinizing hormone （LH） in crustaceans may further elucidate the regulation mechanisms in arthropod repro-duction. Using immunocytochemical staining techniques, this study has localized vertebrate FSH-like and LH-like substances in neurons in the subesophageal and thoracic ganglia from the thoracic ganglion mass （TGM） of Scylla paramamosain （Crustacea： Decapoda： Brachyura）. Enzyme-linked immunosorbent assay （ELISA） has shown that the concentrations of both FSH-and LH-like sub-stances increased markedly in the TGM during the vitellogenic stage compared with that in the previtellogenic stage. These results indicate that substances resembling the vertebrate FSH and LH are present in S. paramamosain, and they may be involved in the development of the ovary as well as in ovulation.
基金supported by the grants of National Natural Science Foundation of China (30471155)National 863 Program of China (2006AA06Z411)
文摘Diethylphosphono acetic acid （DPA） was used as a current hapten to generate broad specificity polycolonal antibodies against a group of organophosphorus pesticides. Six New Zealand white rabbits were immunized with immunogens synthesized by the active ester method （AEM） or 1-ethyl-3-（3-dimethylaminopropyl）-carbodimide method （EDC）. The titers of antisera reached 25 600 by AEM and 6 400 by EDC, respectively. Polyclonal antibodies raised against DPA were screened and selected for the competitive indirect enzyme-linked immunosorbent assay （CI-ELISA）. A CI-ELISA for DPA was developed with a detection limit of 3.536 ng mL^-1and an I50 value of 0.182 μg mL^-1. The assay specificity was evaluated by obtaining competitive curves for several structurally related compounds as competitors. The antiserum showed high affinities to chlorpyrifos, diazinon, omethoate, parathion-ethyl and profenofos with I50 of 0.12, 0.15, 0.21, 0.88, 0.97 and 2.5 μg mL^-1, respectively. The results indicate that the assay could be a screening tool for quantitation and semiquantitation determination of the above former five organophosphorus pesticides.
