ABSTRACT
Studies have shown that ABO blood group is related to the susceptibility and disease progression of SARS-CoV-2 infection, and most studies indicated that group O individuals were less likely to get infected while group A conferred a higher susceptibility to infection and propensity to severe disease. ABO blood group antigens are oligosaccharides expressed on red cells and other tissues. People with different ABO blood type have different susceptibility to a variety of pathogens, including SARS-CoV-2. There are several hypotheses to explain the differences in SARS-CoV-2 infection between ABO blood group individuals. Firstly, anti-A and/or anti-B antibodies could bind to corresponding antigens on the viral envelope and contribute to viral neutralization, thereby preventing target cell from being infected. The SARS-CoV-2 virus and SARS-CoV spike (S) proteins may be bound by anti-A isoagglutinin, which may block interactions between virus and angiotensin-converting-enzyme-2-receptor, thereby preventing entering into lung epithelial cells. Secondly, the receptor binding domain (RBD) of S protein domain can bind to antigen A expressed in respiratory epithelium and promote its infection to respiratory epithelial cells. In conclusion, most studies indicated that group O may be associated with a lower risk of SARS-CoV-2 infection while group A with a higher risk along with severe disease, and the related mechanism needs to be further studied.
ABSTRACT
Objective To establish a method of quantiying trace α-galactosidase from Bacteroides fragilis in enzymatic conversion of blood group B to O red blood cells ( B-ECO RBCs) .Methods BALB/c mice were immunized with purified recombinant B.fragilisα-galactosidase ( the purity>90%) to prepare monoclonal antibodies.The ascites were prepared using hybridoma cell lines stably secreting antibody and purified by HiTrap rProtein A column.The antibody titer and spe-cificity were detected by ELISA and Western blotting, respectively.Purified monoclonal antibody and rabbit polyclonal an-tibody were applied to detect residual enzyme in B-ECO RBCs and the washing solution was analyzed by indirect ELISA. Results A high titer and purity antibody was obtained.Western blotting showed that the antibody specifically reacted with B.fragilisα-galactosidase.Moreover, indirect ELISA was sensitive enough to detect the minimal amount of residualα-gal-actosidase at the concentration of 1 ng/ml.After four repeat washing cycles with 1∶4 ( v/v) phosphate-buffered saline, the amount of residual enzyme in B-ECO RBCs was less than 10 ng/ml.Conclusion An effective method of detecting the min-imal amount of residual α-galactosidase in blood conversion is established for safety evaluation of universal RBCs prepara-tion by enzymatic treatment.
ABSTRACT
ObjectiveTo explore the application value of acoustic radiation force impulse(ARFI) in the differential diagnosis of breast lesions.Methods Eighty six patients with 107 lesions were performed ARFI elastography.The stiffness of the masses in virtual touch tissue image(VTI) were scored.The pathological diagnosis as the gold standard,drawed the ROC curve to find the cut off point of area ratio to predict breast cancer.Shear wave velocity(SWV) within the breast masses were measured using virtual touch tissue quantification(VTQ) technique.ResultsThe elastography hardness score higher than grade 4 was mainly distributed in the malignancies compared to benign lesions( P ＜0.01).1.53 as the cut-off point of area ratio,sensitivity and specificity of diagnosing breast cancer were 95.7 ％,92.5 ％.SWV of malignant group higher than benign group,the difference was statistically significant (P ＜ 0.001 ).Conclusions Hardness score in VTI imaging,area ratio of benign and malignant lesions,SWV within the breast masses can help the differential diagnosis of breast lesions.