The use of tetra-substituted ammo aluminum phthalocyanine (TAAIPc) as a new red-region fluorescent substrate for horseradish peroxidase (HRP)-based enzyme-linked immunosorbent assay was investigated. TAAIPc displayed ...The use of tetra-substituted ammo aluminum phthalocyanine (TAAIPc) as a new red-region fluorescent substrate for horseradish peroxidase (HRP)-based enzyme-linked immunosorbent assay was investigated. TAAIPc displayed an excitation maximum at 610 nm and emission maximum at 678 nm in a strong acidic medium. In the presence of HRP, trace amounts of H2O2 could rapidly and significantly react with TAAIPc, thus quenching the fluorescence of TAAIPc. The Michaelis-Menten parameters Km and Vmax were measured to be 2.82 × 10?6 mol/L?1 and 6.0 × 10?9 mol·L?1, respectively. In this paper, TAAIPc was used in an HRP-based enzyme-linked immunosorbent assay (ELISA) of α-fetoprotein (AFP) in human serum with satisfactory results. AFP could be determined in the concentration range of 0.5–200 ng/mL with a detection limit of 0.2 ng/mL, which was close to that of radioimmunoassay. The advantage of proposed method was strongly minimizing the interference resulting from background fluorescence or scattering light and had a high analytical sensitivity.展开更多
The present study examined von Willebrand factor (vWF) levels and ADAMTS13 activity in pregnant and severe preeclamptic women in order to shed light on the prothrombotic state in severe preeclampsia.Thirty healthy wom...The present study examined von Willebrand factor (vWF) levels and ADAMTS13 activity in pregnant and severe preeclamptic women in order to shed light on the prothrombotic state in severe preeclampsia.Thirty healthy women of childbearing age,22 second trimester pregnant women,30 third trimester pregnant women and 10 severe preeclamptic patients were recruited in this study.ADAMTS13 activity was determined by the FRETS-vWF73 assay and vWF antigen (vWF:Ag) levels by an enzyme-linked immunosorbent assay.The results showed that there were statistically significant differences in plasma vWF antigen levels between the severe preeclamptic and third trimester pregnant women,between third and second trimester pregnant women (P【0.05).The third trimester pregnant women had significantly lower plasma ADAMTS13 activity than second trimester pregnant women (P【0.05).Nevertheless,no significant differences in plasma ADAMTS13 activity were found between severe preeclamptic patients and the third trimester pregnant women (P】0.05).In conclusion,plasma ADAMTS13 activity is normal in severe preeclampsia despite the increased vWF:Ag levels.Prothrombotic state is involved in the pathogenesis of severe preeclampsia,as a result of endothelial injury.展开更多
The global pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)virus has necessitated rapid,easy-to-use,and accurate diagnostic methods to monitor the virus infection.Herein,a ratiometric flu...The global pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)virus has necessitated rapid,easy-to-use,and accurate diagnostic methods to monitor the virus infection.Herein,a ratiometric fluorescence enzyme-linked immunosorbent assay(ELISA)was developed using Si-fluorescein isothiocyanate nanoparticles(FITC NPs)for detecting SARSCoV-2 nucleocapsid(N)protein.Si-FITC NPs were prepared by a one-pot hydrothermal method using 3-aminopropyl triethoxysilane(APTES)-FITC as the Si source.This method did not need post-modification and avoided the reduction in quantum yield and stability.The p-nitrophenyl(pNP)produced by the alkaline phosphatase(ALP)-mediated hydrolysis of pnitrophenyl phosphate(pNPP)could quench Si fluorescence in Si-FITC NPs via the inner filter effect.In ELISA,an immunocomplex was formed by the recognition of capture antibody/N protein/reporter antibody.ALP-linked secondary antibody bound to the reporter antibody and induced pNPP hydrolysis to specifically quench Si fluorescence in Si-FITC NPs.The change in fluorescence intensity ratio could be used for detecting N protein,with a wide linearity range(0.01-10.0 and 50-300 ng/mL)and low detection limit(0.002 ng/mL).The concentration of spiked SARS-CoV-2 N protein could be determined accurately in human serum.Moreover,this proposed method can accurately distinguish coronavirus disease 2019(COVID-19)and non-COVID-19 patient samples.Therefore,this simple,sensitive,and accurate method can be applied for the early diagnosis of SARS-CoV-2 virus infection.展开更多
Background Measurement of human epidermal growth factor receptor 2 (HER2) protein in the serum of metastatic breast cancer patients has previously been reported, but there are no consistent data to support the clini...Background Measurement of human epidermal growth factor receptor 2 (HER2) protein in the serum of metastatic breast cancer patients has previously been reported, but there are no consistent data to support the clinical utility of serum HER2 extracellular domain for patients with early stage breast cancer. We aimed to evaluate the correlation between serum extracellular domain levels and tissue HER2 expression, and analyzed their relationship with clinico-pathological parameters in patients with early stage disease. Methods A prospective study was conducted on 232 breast cancer patients with stage I-III prior to treatment. Preoperative serum samples were measured by enzyme-linked immunosorbent assay. Tissue HER2 status was analyzed by immunohistochemistry and fluorescence in situ hybridization assays. Results The median serum extracellular domain concentration was 6.8 ng/ml. The best diagnostic cut-off value was 7.4 ng/ml, with 62.9% sensitivity and 85.3% specificity. High serum extracellular domain levels were reported in 89 patients (38.3%), and HER2-positive expression was observed in 77 patients (33.2%). Multivariate analysis showed that elevated serum extracellular domain correlated with postmenopausal status (P 〈0.001), high histological grade (P 〈0.001), negativity of both estrogen (P=0.012) and progesterone receptors (P 〈0.001), and high levels of carcinoembryonic antigen 153 (P=-0.048). Conclusions We recommend that 7.4 ng/ml should be used as the cut-off value when evaluating serum extracellular domain levels in early stage of breast cancer. Patients with high serum extracellular domain levels have a certain clinico- pathological characteristics, may provide a basis for clinical practice.展开更多
文摘The use of tetra-substituted ammo aluminum phthalocyanine (TAAIPc) as a new red-region fluorescent substrate for horseradish peroxidase (HRP)-based enzyme-linked immunosorbent assay was investigated. TAAIPc displayed an excitation maximum at 610 nm and emission maximum at 678 nm in a strong acidic medium. In the presence of HRP, trace amounts of H2O2 could rapidly and significantly react with TAAIPc, thus quenching the fluorescence of TAAIPc. The Michaelis-Menten parameters Km and Vmax were measured to be 2.82 × 10?6 mol/L?1 and 6.0 × 10?9 mol·L?1, respectively. In this paper, TAAIPc was used in an HRP-based enzyme-linked immunosorbent assay (ELISA) of α-fetoprotein (AFP) in human serum with satisfactory results. AFP could be determined in the concentration range of 0.5–200 ng/mL with a detection limit of 0.2 ng/mL, which was close to that of radioimmunoassay. The advantage of proposed method was strongly minimizing the interference resulting from background fluorescence or scattering light and had a high analytical sensitivity.
基金supported by grants from National Natural Sciences Foundation of China(No.30672243,No.30671093)Natural Sciences Foundation of Hubei Province(No.ZR-Y1271)
文摘The present study examined von Willebrand factor (vWF) levels and ADAMTS13 activity in pregnant and severe preeclamptic women in order to shed light on the prothrombotic state in severe preeclampsia.Thirty healthy women of childbearing age,22 second trimester pregnant women,30 third trimester pregnant women and 10 severe preeclamptic patients were recruited in this study.ADAMTS13 activity was determined by the FRETS-vWF73 assay and vWF antigen (vWF:Ag) levels by an enzyme-linked immunosorbent assay.The results showed that there were statistically significant differences in plasma vWF antigen levels between the severe preeclamptic and third trimester pregnant women,between third and second trimester pregnant women (P【0.05).The third trimester pregnant women had significantly lower plasma ADAMTS13 activity than second trimester pregnant women (P【0.05).Nevertheless,no significant differences in plasma ADAMTS13 activity were found between severe preeclamptic patients and the third trimester pregnant women (P】0.05).In conclusion,plasma ADAMTS13 activity is normal in severe preeclampsia despite the increased vWF:Ag levels.Prothrombotic state is involved in the pathogenesis of severe preeclampsia,as a result of endothelial injury.
基金supported by the National Key Research and Development Program of China(No.2021YFA0910900)the National Natural Science Foundation(No.22104147)+4 种基金Youth Innovation Promotion Association CAS(No.2021359)the Natural Science Foundation of Guangdong(Nos.2018B030306046 and 2020A1515111130)Guangdong Provincial Key Laboratory of Synthetic Genomics(No.2019B030301006)Shenzhen Science and Technology Program(No.KQTD20180413181837372)Shenzhen Outstanding Talents Training Fund.
文摘The global pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)virus has necessitated rapid,easy-to-use,and accurate diagnostic methods to monitor the virus infection.Herein,a ratiometric fluorescence enzyme-linked immunosorbent assay(ELISA)was developed using Si-fluorescein isothiocyanate nanoparticles(FITC NPs)for detecting SARSCoV-2 nucleocapsid(N)protein.Si-FITC NPs were prepared by a one-pot hydrothermal method using 3-aminopropyl triethoxysilane(APTES)-FITC as the Si source.This method did not need post-modification and avoided the reduction in quantum yield and stability.The p-nitrophenyl(pNP)produced by the alkaline phosphatase(ALP)-mediated hydrolysis of pnitrophenyl phosphate(pNPP)could quench Si fluorescence in Si-FITC NPs via the inner filter effect.In ELISA,an immunocomplex was formed by the recognition of capture antibody/N protein/reporter antibody.ALP-linked secondary antibody bound to the reporter antibody and induced pNPP hydrolysis to specifically quench Si fluorescence in Si-FITC NPs.The change in fluorescence intensity ratio could be used for detecting N protein,with a wide linearity range(0.01-10.0 and 50-300 ng/mL)and low detection limit(0.002 ng/mL).The concentration of spiked SARS-CoV-2 N protein could be determined accurately in human serum.Moreover,this proposed method can accurately distinguish coronavirus disease 2019(COVID-19)and non-COVID-19 patient samples.Therefore,this simple,sensitive,and accurate method can be applied for the early diagnosis of SARS-CoV-2 virus infection.
文摘Background Measurement of human epidermal growth factor receptor 2 (HER2) protein in the serum of metastatic breast cancer patients has previously been reported, but there are no consistent data to support the clinical utility of serum HER2 extracellular domain for patients with early stage breast cancer. We aimed to evaluate the correlation between serum extracellular domain levels and tissue HER2 expression, and analyzed their relationship with clinico-pathological parameters in patients with early stage disease. Methods A prospective study was conducted on 232 breast cancer patients with stage I-III prior to treatment. Preoperative serum samples were measured by enzyme-linked immunosorbent assay. Tissue HER2 status was analyzed by immunohistochemistry and fluorescence in situ hybridization assays. Results The median serum extracellular domain concentration was 6.8 ng/ml. The best diagnostic cut-off value was 7.4 ng/ml, with 62.9% sensitivity and 85.3% specificity. High serum extracellular domain levels were reported in 89 patients (38.3%), and HER2-positive expression was observed in 77 patients (33.2%). Multivariate analysis showed that elevated serum extracellular domain correlated with postmenopausal status (P 〈0.001), high histological grade (P 〈0.001), negativity of both estrogen (P=0.012) and progesterone receptors (P 〈0.001), and high levels of carcinoembryonic antigen 153 (P=-0.048). Conclusions We recommend that 7.4 ng/ml should be used as the cut-off value when evaluating serum extracellular domain levels in early stage of breast cancer. Patients with high serum extracellular domain levels have a certain clinico- pathological characteristics, may provide a basis for clinical practice.