Objective:To evaluate the performance of three antibody kits for novel coronavirus (SARS-CoV-2) and to investigate the feasibility and advantages of them in clinical application.Methods:A total of 104 patients who were admitted to Guangzhou Eighth People′s Hospital with COVID-19 from January to February 2020 were selected as research group. Fifty-one healthy subjects were selected during the same period as negative control group. Serum antibodies (IgM/IgG) against SARS-CoV-2 were detected using two kinds of colloidal gold kits (A and B kits) and one chemiluminescence kit (C kit). The positive rates of SARS-CoV-2 nucleic acid in different samples from patients with COVID-19 were retrospectively analyzed.Results:The clinical sensitivity of A kit to detect SARS-CoV-2-specific IgM and IgG was 77.88% (81/104) and 65.38% (68/104), respectively, and the clinical specificity was 70.59% (36/51) and 100.00% (51/51). However, the false positive rate in IgM detection was as high as 29.41% (15/51). The sensitivity of B kit to test total antibodies to SARS-CoV-2 was 63.46% (66/104), and the clinical specificity was 94.12% (48/51). The clinical sensitivity of C kit to detect SARS-CoV-2-specific IgM and IgG were respectively 31.73% (33/104) and 64.42% (67/104), and the clinical specificity were both 98.04% (50/51). There was a moderate correlation between the detection results of two colloidal gold kits and the chemiluminescence kit with the Kappa values of 0.462 and 0.587 ( Z=6.157, P<0.01; Z=7.345, P<0.01). C kit had the highest positive detection rate for IgG, and would be more reliable to be used for IgG detection in COVID-19 patients 14 d after onset. The total positive detection rate of nucleic acid in all types of samples was 63.46% (66/104). The highest positive detection rate was in throat swabs or sputum samples, followed by those in blood samples and anal swabs. No viral nucleic acid was detected in urine samples for the time being. Conclusions:SARS-CoV-2-specific antibodies could be detected in the early or late stage of COVID-19. The method of antibody detection has the advantages of shorter detection time, simple operation and high biological safety, indicating that it could be used as a supplementary or auxiliary detection for the diagnosis of suspected COVID-19 cases with negative nucleic acid test results. The chemiluminescence kit has good sensitivity and specificity, and is well recommended for clinical laboratories.

Objective:To explore the mechanism of bone morphogenetic protein 2 (BMP-2) regulating pulmonary vascular remodeling in pulmonary hypertension (PH).Methods:Pulmonary artery smooth muscle cells (PASMC) groups: control group, PH group, PH+BMP-2 group, PH+BMP-2+ small interfering BMP receptor(si-BMPR)-Ⅰa group, PH+BMP-2+ si-BMPR-Ⅰb group, PH+BMP -2+si-BMPR-Ⅱ group. In vitro PH model was induced by hypoxia. The three BMP-2 receptors were silenced by the transfection of si-BMPR-Ⅰa, si-BMPR-Ⅰb and si-BMPR-Ⅱ plasmids, respectively. Cell proliferation and apoptosis in each group were detected, transient receptor potential ion channel C1/6 (TRPC1/6), p21 mRNA and protein levels, and intracellular Ca 2+ concentration were detected. Results:The intracellular Ca 2+ concentration in the PH group was higher than that in the control group: (785.15 ± 44.26) nmol/L vs. (224.15 ± 15.87) nmol/L, the and apoptosis rate was lower than that in the control group: (3.15 ± 0.22)% vs. (7.31 ± 0.45)%, there were statistical differences ( P<0.05). The intracellular Ca 2+ concentration in the PH+BMP-2 group was (297.64 ± 21.46) nmol/L, and was lower than that in the PH group, and apoptosis rate was (6.88 ± 0.75)%, and was higher than that in the PH group, there were statistical differences ( P<0.05). The intracellular Ca 2+ concentration in the PH+BMP-2+si-BMPR-Ⅰa group, PH+BMP-2+ si-BMPR-Ⅰb group, PH+BMP -2+si-BMPR-Ⅱ group was (412.31 ± 29.57), (384.34 ± 30.66), (695.23 ± 39.85) nmol/L, and was higher than that in the PH+BMP-2 group, and apoptosis rate was (4.10 ± 0.27)%, (4.26 ± 0.28)%, (3.33 ± 0.24)%, and was lower than that in the PH+BMP-2 group, there were statistical differences ( P<0.05). The intracellular Ca 2+ concentration in the PH+BMP -2+si-BMPR-Ⅱ group was higher than that in the PH+BMP-2+si-BMPR-Ⅰa group and PH+BMP-2+ si-BMPR-Ⅰb group, the apoptosis rate was lower than that in the PH+BMP-2+si-BMPR-Ⅰa group and PH+BMP-2+ si-BMPR-Ⅰb group, there were statistical differences ( P<0.05). Conclusions:BMP-2 mainly inhibits the expression of TRPC1/6 by interacting with the receptor BMPR-Ⅱ, inhibits the influx of Ca 2+ and promotes the expression of p21, thereby inhibiting the proliferation of PASMC and promoting apoptosis, participating in pulmonary vascular remodeling in PH.

Objective:To construct and validate a predictive model for the risk of excessive blood loss in pa-tients with ruptured tubal pregnancy,and to provide a basis and tool for the assessment of changes in the condi-tion of patients with ruptured tubal pregnancy.Methods:Clinical data of inpatients with ruptured tubal pregnancy from January 2014 to July 2021 were retrospectively analyzed,who underwent surgical treatment in the Depart-ment of Gynecology,Dongguan Maternal and Child Health Hospital.The pelvic blood volume was categorized into excessive blood loss and non-excessive blood loss groups based on whether the amount of pelvic blood was found to be≥750 ml intraoperatively.Factors influencing the occurrence of excessive blood loss were screened and modeled by univariate analysis,Lasso regression,and multi-factor Logistic stepwise regression.The area un-der the subject working characteristic curve(AUC)was used to evaluate the discrimination of the predictive mod-el,the model's consistency was evaluated by calibration curve and goodness-of-fit test,and the clinical utility of the model was evaluated and validated by the decision analysis curve.Finally,column line plots were drawn.Results:①A total of 386 patients with ruptured tubal pregnancy were included,of whom 124(32.12%)had blood loss≥750 ml.②The optimal predictors for predicting concomitant blood loss in patients with ruptured tubal preg-nancy were screened,including:days of abdominal pain,dizziness,pallor,fatigue,the maximum diameter of para-metrial mass,human chorionic gonadotropin(β-hCG),and hemoglobin(Hb)and the model and the column line graphswere constructed accordingly.③The prediction model AUC was 0.827(95%CI 0.781-0.873);the cut-off value was 0.391,at which point the specificity and sensitivity were 68.55%and 84.35%,respectively,and the AUC validated within the model by resampling was 0.804.Clinical decision curves showed that the threshold probability intervals for the maximum net benefit values ranged from 8.5%-97%,respectively.Conclusions:The constructed prediction model was validated to suggest good discriminatory efficacy and degree of consistency.As a tool,it has clinical application value in predicting the risk of hemorrhage in patients with ruptured tubal pregnan-cy.It can help to determine the occurrence of adverse events such as hemorrhagic shock at an early stage and improve the success rate of rescue treatment.