ABSTRACT
【Objective】 To further determine the relationship between blood donor role cognition and blood donation behavior, then prepare of blood donor role identity scale(BDRIS). 【Methods】 The preparation of the scale was divided into five stages. It includes literature retrieval, expert interview, construction of the basic framework of the scale, scale test and statistical index test. The study focused on items selection, dimensions identification, measurement reliability, content and structural validity. 【Results】 The blood donor role identity scale consisted of 35 items. Exploratory factor analysis divided the items into six common factors, including role identity, role expectation, current situation of blood collection and supply, role conflict, external reward and blood donation experience. The α of scale was 0.840. 【Conclusion】 The reliability and validity of the scale meet the basic measurement requirements, and the framework of the blood donor role scale is basically formed. It can be used as one of the means to explore the ways and mechanisms of the role identity of blood donors in blood donation behavior.
ABSTRACT
To investigate the duration of humoral immune response in convalescent coronavirus disease 2019 (COVID-19) patients, we conduct a 12-month longitudinal study through collecting a total of 1,782 plasma samples from 869 convalescent plasma donors in Wuhan, China and test specific antibody responses. The results show that positive rate of IgG antibody against receptor-binding domain of spike protein (RBD-IgG) to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the COVID-19 convalescent plasma donors exceeded 70% for 12 months post diagnosis. The level of RBD-IgG decreases with time, with the titer stabilizing at 64.3% of the initial level by the 9th month. Moreover, male plasma donors produce more RBD-IgG than female, and age of the patients positively correlates with the RBD-IgG titer. A strong positive correlation between RBD-IgG and neutralizing antibody titers is also identified. These results facilitate our understanding of SARS-CoV-2-induced immune memory to promote vaccine and therapy development.
ABSTRACT
Objective To dynamically analyze the antibodies with regard to in vitro serum bacteri-cidal activity and the quantity of IgG in healthy adults received one dose of immunization with ACYW 135 me-ningococcal polysaccharide vaccine .To investigate the term of protection with polysaccharide vaccine and the correlation between bactericidal titer and IgG concentration .Methods Twenty healthy adults were given one dose of immunization with quadrivalent meningococcal polysaccharide vaccine .Serum samples were col-lected before and after vaccination at specific time points .Test for serum bactericidal activity ( SBA ) and quantitative ELISA were performed to detect bactericidal titers and IgG concentrations in serum samples .Re-sults Certain levels of antibodies against capsular polysaccharides of serogroup A , C, Y and W135 strains had already existed prior to immunization .Moreover, bactericidal titers against serogroup A , Y and W135 strains except serogroup C strain were relatively high .Specific IgG concentrations and bactericidal titers for all serogroup stains were significantly increased on day 15 after vaccination (P0.05).However, a close correla-tion was demonstrated between GMTs and GMCs of serum samples (r>0.7, P<0.05).Conclusion The geometric mean titers ( GMTs) and geometric mean concentrations ( GMCs) of serum samples collected be-fore and after vaccination at different time points were reliable and consistent parameters for the evaluation of vaccine .The term of protection of quadivalent meningococcal polysaccharide vaccine was about 3 years upon a single dose of immunization .
ABSTRACT
Objective To prepare a human meningococcal reference serum and standardize IgG concentrations to capsular polysaccharides and in vitro bactericidal activities of the reference serum against serogroup A, C, Y and W135 strains.Methods Twenty healthy adults were recruited and given one dose of immunization with tetravalent (serogroups A, C, Y and W135) meningococcal polysaccharide vaccine . Plasma samples were collected and gone through a series of process treatments including defibrination , filtra-tion, and lyophilization to prepare the meningococcal reference serum Men 10.The IgG concentrations of Men10 to capsular polysaccharides of serogroups A , C, Y and W135 were calibrated by using an internation-al reference serum CDC1992 as the standard in enzyme-linked immunosorbent assay (ELISA).Provisional IgG concentrations of Men10 were intensively validated by testing a panel of 12 calibration serum samples from Centers for Disease Control and Prevention , USA ( US CDC) and a panel of 56 serum samples immu-nized with A, C, Y and W135 meningococcal polysaccharide vaccine from Lanzhou Institute of Biological Products Co., Ltd.(LIBP) with the assays using Men10 and CDC1992 as the standard and/or test sam-ples, respectively.The bactericidal titers against serogroup A , C, Y and W135 strains were measured by se-rum bactericidal assay (SBA).Results Four thousand vials (0.5 ml/vial)of lyophilized human meningo-coccal reference serum Men10 were successfully prepared with 2.5%of residual moisture .Reference serum Men10 was sterile and free from contamination by hepatitis B virus , hepatitis C virus , human immunodefi-ciency virus and syphilis .Provisional IgG concentration of Men 10 to capsular polysaccharide of serogroups A, C, Y and W135 was calibrated by using CDC1992 as the standard.Furthermore, IgG concentrations of both panels of 12 CDC calibration serum samples and 56 LIBP serum samples calibrated by using Men 10 as the standard correlated well with those by using CDC1992 as the standard (r=0.99,P<0.05).The IgG concentrations of CDC1992 as calibrated by using Men10 as the standard showed significant correlation with its previously determined values with variation <10%.SBA titers for serotype A , C, Y and W135 strains were established as well .Conclusion A panel of new human meningococcal reference serum Men 10 with accurately calibrated IgG concentration against capsular polysaccharide of serogroups A , C, Y and W135 as well as SBA titers was successfully established .
ABSTRACT
The Caco-2 cell model was widely applied in the research of absorption,metabolism and toxicity of drugs, especially in the aspect of anticancer,inorganic and traditional Chinese medicine,It has become an important tool of the study on medicine.
