ABSTRACT
【Objective】 To study the expression level of ABO blood group antigen on the surface of platelets of blood donors. 【Methods】 A total of 506 donors with normal ABO blood group were selected to analyze the ABO antigen on platelets by flow cytometry. Among them, 30 donors were selected to monitor the changes of ABO antigen on platelets during the storage period, and the remaining 476 to analyze the expression difference of ABO antigen among blood donors. 【Results】 The ABO antigen on platelets of each sample fluctuated slightly but was relatively stable over 1~7 days in vitro. According to MFI values, the donors were divided into low-, moderate- and high- expression groups, with the average frequency of 59.6%, 35.5% and 4.9%, respectively. The A and B antigens of blood group AB platelets exhibited a competitive co-expression pattern. 【Conclusion】 Most individuals have low-expression phenotype of ABO antigen on platelets and can be potential platelet donors for ABO-incompatibility transfusion, which is helpful to improve platelets transfusion strategy.
ABSTRACT
Extra-articular distal tibial fractures as a result of high-energy damage are often comminuted or displaced, frequently accompanied by severe soft tissue injuries.Poor blood supply and various complications make the treatment more difficult,affecting life quality of the patients.The main goals of the treatment are to abtain a healed,well-aligned fracture,functional range of motion of the ankle joint and minimizing complications.It is generally recommended that surgical treatment be performed in the proper context of local conditions to facilitate early functional exercise.Plate fixation and intramedullary nail fixation are the common options for closed fractures.This article focuses on the two treatment methods and some important auxiliary technologies in both domestic and foreign, hoping to provide some references for clinical treatment.
ABSTRACT
Objective To investigate the biomechanical properties of our self-designed 4 cannulated screws in 4 configurations for fixation of extremely unstable femoral neck fractures.Methods Twelve adult cadaveric femoral specimens were randomly divided into 4 equal groups (n =3) and made into models of extremely unstable femoral neck fracture combined with comminution (Pauwels type Ⅲ).Group A was subjected to fixation in configuration of “double axial compressions plus double stabilizations”,group B to configuration of “positive triangle parallel compression plus small angle screwing”,group C to configuration of “inverted triangle parallel compression plus small angle screwing”,and group D to configuration of “diamond pattern screwing”.Static compression tests,cyclic loading tests and limit load tests were carried out for the 4 groups on a biomechanical testing machine.Results For groups A,B C and D,the axial compression stiffness was respectively 995.29 ±34.16 N/mm,509.89 ± 138.90 N/mm,559.28 ± 111.25 N/mm and 610.18 ±232.35 N/mm,and the limit load was respectively 3,225.33 ±461.31 N,2,008.67 ±237.27 N,2,705.67 ±496.39 N and 2,395.33 ±403.71 N,showing significant differences between the 4 groups (P ＜ 0.05).For groups A,B C and D,the displacement was respectively 0.46 ± 0.10 mm,1.47 ± 0.72 mm,1.14 ±0.24 mm and 1.22 ±0.22 mm,and the limit stiffness was respectively 1,139.28 ±342.09 N/mm,843.56 ±408.91 N/mm,585.98 ± 81.60 N/mm and 729.96 ±251.37 N/mm,showing no significant differences between the 4 groups (P ＞ 0.05).Conclusions In the fixation of extremely unstable femoral neck fracture with our self-designed 4 cannulated screws,the configuration of “double axial compressions plus double stabilizations” may lead to the greatest biomechanical advantage while the configuration of “positive triangle parallel compression plus small angle screwing” may result in the poorest biomechanical properties.