Objective:To characterize the allele frequencies and its polymorphisms of human platelet antigen (HPA) in Guangzhou population.Methods:A total of 500 samples from healthy voluntary platelet donors in Guangzhou were genotyped for HPA-1 to-17 by PCR-SSP.Results:HPA-1a to-17a alleles were found in each of the samples;The gene frequencies of HPA-1a to-17a were 99.8%,99.85%,56.3%,99.9%,98.8%,98.6%,100%,100%,100%,100%,100%,100%,100%,100%,55.1%,and 100%,100% respectively.The gene frequencies of HPA-1b to-6b and-15b alleles were 0.2%,0.15%,43.7%,0.1%,1.2%,1.4% and 44.9% respectively;HPA-7b to-14b and-16b-17b were not detected.In summary Guangzhou population displayed higher frequency of HPA-1a to-17a and HPA-3b,-15b.Compared with those of other Han populations in China,HPA frequency of Guangzhou people was significantly different from that of Beijing;Compared to that of the European,American,English and Egyptians,HPA frequency was different significantly.While HPA frequency was different from those of Japanese and Thais.This study for the first time investigated the assortment of HPA genes and its frequency,there were 40 assortments in Guangzhou population,only 5 assortment of HPA gene frequencies more than 10%,35 assortment of HPA gene frequencies less than 9%.Conclusion:HPA distribution in Guangzhou population appears to have local characteristics.This study confirms the ethnic and original difference of HPA.The allele frequencies and its polymorphisms of HPA in Han population are shown North-South differences.Races and countries outside Asia are also shown differences.The basic information provided by this study of the HPA system polymorphisms is useful to guide the design of the local HPA genotype database of volunteer platelet donors.It's also useful to avoid the PTR,and the HPA related clinical research.

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.

Objective To establish a cell line stably expressing the human CD36 by using TA clo-ning and cell transfection technology and to analyze its application to the detection of anti-CD36 antibodies. Methods Total RNA was isolated from human platelets and then used to synthesize complementary DNA ( cDNA) . Sequence of the gene encoding CD36 on human platelets was obtained by PCR amplification. The recombinant vector was transformed into TOP10 E. coli after TA cloning. The positive recombinant pcDNA3. 1/V5-CD36 plasmid was screened out by blue-white selection and then sequenced. The correctly constructed plasmid coated with Effectene? Transfection Reagent was transferred into HEK293T cells. Fluo-rescence-activated cell sorting was performed to screen out the cell line that could stably express the CD36 on human platelets. The transfected cell line-based flow cytometry analysis and antibody capture assay ( ACA) were established and used for antibody detection in nine serum samples positive for anti-CD36 antibodies. Results The HEK293T cell line stably expressing the recombinant CD36 was successfully established. Compare with the monoclonal antibody immobilization of platelet antigens assay ( MAIPA) , anti-CD36 anti-bodies could be easily identified in nine serum samples by using the transfected cell line-based flow cytome-try analysis and ACA. Conclusion This study suggests that the HEK293T cells stably expressing the re-combinant CD36 could be used in flow cytometry analysis and ACA for the detection of anti-CD36 antibod-ies. It also paves the way for further researches on the mechanism of CD36 in other diseases.

Objective:To investigate the clinical efficacy of proximal femoral nail anti-rotation (PFNA) assisted by the "3-2-1" surface positioning method in the treatment of femoral subtrochanteric fractures.Methods:A total of 97 patients with subtrochanteric fractures admitted to the Second Hospital of Fuzhou from January 2015 to December 2020 were retrospectively analyzed. They were divided into two groups according to whether the "3-2-1" surface positioning method (3 longitudinal axes, 2 preset incisions, and 1 auxiliary incision) was used. There were 44 patients in the surface positioning group, including 25 males and 19 females, aged 61.59±18.43 years (range, 22-90 years). According to the Seinsheimer classification, there were 13 cases of type II, 11 cases of type III, 6 cases of type IV, and 14 cases of type V. The mechanism of injury was low energy injury in 26 cases and high energy injury in 18 cases. There were 53 patients in the traditional positioning group, including 30 males and 20 females, aged 56.38±17.24 years (range, 24-90 years). According to the Seinsheimer classification, there were 9 cases of type II, 22 cases of type III, 9 cases of type IV, and 13 cases of type V. According to the mechanism of injury, there were 30 cases of low energy injury and 23 cases of high energy injury. The length of incision, operation time, and blood loss were recorded. At 1, 3, 6, and 12 months after operation, the anteroposterior and lateral X-ray films of the hip were taken to evaluate the imaging indicators (neck-shaft angle, anteroposterior and lateral displacement, and angulation), fracture healing, and complications (infection, malunion, loosening and breakage of the internal fixation, and periprosthetic fracture). The Harris hip score and EuroQol five dimensions questionnaire (EQ-5D) were evaluated.Results:All patients successfully completed the operation and were followed up for 15.12±1.54 months (range, 12-18 months). The operation time, incision length, dominant blood loss and hidden blood loss in the surface positioning group were 1.78(1.50, 2.00) h, 8(8, 9) cm, 300(200, 400) ml and 843(629, 1 130) ml, respectively, which were less than 2.10(1.69, 2.38) h, 10(9, 12) cm, 400(300, 500) ml and 1 030(954, 1 266) ml in the traditional positioning group, and the difference was statistically significant ( P<0.05). The neck-shaft angle in the surface positioning group was 135.54°±2.83°, which was larger than 132.33°±3.37° in the traditional positioning group, and the difference was statistically significant ( t=5.02, P<0.001). The anterolateral and lateral displacement and lateral image angle in the surface positioning group were 4.70±1.60 cm, 4.52±1.71 cm and 9.36°±2.94°, respectively, which were lower than 6.14±2.57 cm, 5.98±2.70 cm and 11.46°±4.68° in the traditional positioning group, and the difference was statistically significant ( P<0.05). One year after operation, the Harris hip score and EQ-5D score of the surface positioning group were 92(84, 99) points and 0.90(0.73, 1.00) points, respectively, which were higher than 88(74, 96) points and 0.81(0.72, 0.94) points of the traditional positioning group ( P<0.05). Conclusion:The "3-2-1" surface positioning method assisted PFNA internal fixation in the treatment of femoral subtrochanteric fracture can improve the quality of reduction, reduce intraoperative blood loss, and improve hip function and quality of life.

Antibodies against human CD36 are responsible for several immune-mediated disorders. The detection of anti-CD36 antibodies using the standard monoclonal antibody (mAb) immobilization of platelet antigens (MAIPA) assay is hampered by a high frequency of false-negative results, most likely due to competitive inhibition of the mAb used as the capture antibody. We generated a panel of mouse mAbs against CD36 and seven hybridomas (GZ-3, GZ-13, GZ-70, GZ-143, GZ-413, GZ-507, and GZ-608), which were selected for MAIPA assays, as they reacted with mouse and human CD36. Fourteen anti-CD36 sera were assayed; all of which showed a positive reaction in a PakPlus (Immucor GTI Diagnostics, Inc., Waukesha, WI, USA) ELISA-based screening (optical density: 0.257–2.292). When the reference anti-CD36 mAb FA6-152 was used in the MAIPA assay, only 6/14 (42.9%) sera displayed a positive reaction. In contrast, anti-CD36 antibodies were detected in 13/14 (92.9%) sera when GZ-70 and GZ-608 mAbs were used. This significant improvement resulted in the identification of anti-CD36 antibodies by an antigen capture assay. Since patient’s platelets possibly carrying rare native antigens are used, this method will facilitate the identification of new platelet antibodies against CD36 that are involved in immune-mediated thrombocytopenia and other diseases, such as transfusion-related acute lung injury.

OBJECTIVE: To construct eukaryotic expression vectors for human platelet CD36 gene 220 C>T and 429+4insg variants and analyze their expressions in HEK293T cells. METHODS: RNA was isolated from human platelets and reversely transcribed into cDNA. Sequences of 220C>T and 429+4insg variants were derived by PCR amplification. The target sequence was ligated into a pcDNA3.1/V5-His-TOPO vector by TA cloning, which was transformed into TOP10 E. coli. Positive plasmids were screened by blue-white selection. After sequencing, plasmid DNA carrying 220C>T or 429+4insg variant was used to transfect HEK293T cells with the help of effectene. Expression of CD36 protein was then analyzed by flow cytometry and Western blotting. RESULTS: An eukaryotic expression vector pcDNA3.1/V5-His-CD36 (220C>T/429+4insg) was constructed by TA cloning. After transfected into HEK293T cells, the 220C>T and 429+4insg variants resulted in CD36 deficiency in HEK cells, which was confirmed by flow cytometry and Western blotting. CONCLUSION The 220C>T and 429+4insg variants can cause CD36 deficiency in human platelets. This system may be used for assessing the effect of 220C>T, 429+4insg, and other variants on the expression of CD36.
Blood Platelets ; CD36 Antigens ; Cloning, Molecular ; Escherichia coli ; Eukaryota ; Genetic Vectors ; HEK293 Cells ; Humans ; Plasmids ; Transfection

Objective:To evaluate the clinical efficacy of modified anterior subacromial approach plate internal fixation for three- or four-part valgus impacted proximal humeral fractures.Methods:A retrospective analysis of 35 patients treated between November 2018 and November 2021 at Fuzhou Second General Hospital was performed, including 15 males and 20 females aged 61.7±7.8 years (range: 40 to 73 years). Patients were classified under the Neer system; 17 had 3-part fractures and 18 had 4-part fractures. The modified approach accessed the fracture site via the natural interval of the deltoid anterior bundle, facilitating fracture reduction and fixation using a plate. Operative time, incision length, intraoperative fluoroscopy time, follow-up duration, Constant-Murley score, fracture healing time, visual analogue scale (VAS) for pain, and humeral neck-shaft angle were assessed. Intraoperative and postoperative complications were also recorded.Results:All patients underwent successful surgery, with an average incision length of 8.1±0.3 cm (range, 7.6-9.0 cm) and intraoperative fluoroscopy time of 6.6±0.3 seconds (3-part fractures: 6.3±0.2 s, 4-part fractures: 6.8±0.2 s, t=6.350, P<0.001). Follow-up averaged 22.1±5.8 months (range, 14-31 months). Fracture healing occurred in 11.8±1.4 weeks (range, 10-15 weeks). At the final assessment, the VAS score was 1.6±0.7 (range, 1-3), the Constant-Murley score was 89.6±2.9 (range, 84-95), and the humeral neck-shaft angle was 133.4°±3.1° (range, 128°-138°; 3-part fractures: 133.6°±3.5°, 4-part fractures: 133.3°±2.8°, t=0.288, P=0.075). No complications such as avascular necrosis of the humeral head, varus collapse of the fracture site, or axillary nerve injury were recorded. Conclusion:The modified anterior subacromial approach plate internal fixation is a minimally invasive, safe, and effective treatment for valgus impacted three- and four-part proximal humeral fractures, demonstrated by excellent surgical outcomes and absence of major complications.

Objective To analyze the structure of CD36,search the possible B cell epitopes and prepare multi-antigen peptides(MAP)with B cell epitopes,so as to provide a preliminary experimental basis for the preparation of CD36 antibod-ies using MAP with B cell epitopes.Methods The potential B cell epitopes of CD36 were analyzed by bioinformatics meth-ods,including physical and chemical properties,secondary structure,potential phosphorylation and glycosylation sites.Eight-branch MAP with CD36 B cell epitopes were synthesized by FMOC using polylysine as the core matrix.The purity of MAPs was analyzed by reverse high-performance liquid chromatography chromatography(RP-HPLC),and the molecular weight of MAPs was determined by mass spectrometry.Results CD36 is a stable and hydrophilic alkaline protein,with multiple phosphorylation and glycosylation sites and strong antigenicity,and its secondary structure is mainly characterized by irregular curls.Four potential B cell epitopes were obtained and 4 MAPs containing potential B cell epitopes were pre-pared.RP-HPLC analysis showed that the purity of the MAPs were above 85%,and the molecular weight of 3 MAPs was consistent with the expected theoretical molecular weight.Conclusion CD36 on platelet has strong antigenicity.MAPs con-taining CD36 B cell epitopes can provide the experimental basis for the preparation and related research of CD36 antibodies.

Objective: To explore the role of the c.598G>A mutation of the ITGB3 gene in the occurrence of fetal and neonatal alloimmune thrombocytopenia (FNAIT) through its expression in vitro. Methods: The platelet antibodies in the sera of the affected neonate and her mother were detected using commercial enzyme-linked immunosorbent assay (ELISA), solid-phase agglutination, flow cytometry and the gold standard monoclonal antibody-specific immobilization of platelet antigens (MAIPA). The common human platelet antigen (HPA) genotypes of the neonate and her parents were obtained using the HPA-SSP method. The presence of mutations was analyzed by sequencing the exons of the ITGB3 and ITGA2B genes. The target gene of ITGB3 was obtained by PCR amplification using the existing human platelet cDNA. The wild-type ITGB3 eukaryotic expression vector was constructed by TA cloning technology. The 598G>A mutant ITGB3 eukaryotic expression vector was obtained by point mutation, and the plasmid DNA was co-transfected with that of ITGA2B (αⅡb) into HEK293 cells. The transfected cells stably expressing GP Ⅱb/Ⅲa were screened and obtained. The expression of GP Ⅱb/Ⅲa in 598G>A mutant transfected cells and the presence of antibodies against this mutation in the serum of mother were detected by flow cytometry and MAIPA. Results: Antibodies against HLA-class Ⅰ and GP Ⅱb/Ⅲa glycoproteins were detected in the serum of the neonate's mother, and subsequent HLA antibody-specific testing confirmed the presence of antibodies against HLA-B 57∶01 and A 02∶05. ITGB3 sequencing showed that the neonate and her father carried the c.598G>A point mutation, which results in the change of glutamate to lysine at position 200. Antibodies against GP Ⅱb/Ⅲa glycoproteins were not detected using constructed c.598G>A mutant transfected cells reacted with the maternal serum. Conclusion: The in vitro expression and analysis of the ITGB3 c.598G>A mutation did not support a role for this mutation in the pathogenesis of FNAIT. The establishment of this method facilitates the discovery of new platelet low-frequency antigens, and provides a theoretical foundation for the detection of antibodies against platelet antigens associated with patients with adverse pregnancy and childbirth histories.

Objective: To explore the role of the c.598G>A mutation of the ITGB3 gene in the occurrence of fetal and neonatal alloimmune thrombocytopenia (FNAIT) through its expression in vitro. Methods: The platelet antibodies in the sera of the affected neonate and her mother were detected using commercial enzyme-linked immunosorbent assay (ELISA), solid-phase agglutination, flow cytometry and the gold standard monoclonal antibody-specific immobilization of platelet antigens (MAIPA). The common human platelet antigen (HPA) genotypes of the neonate and her parents were obtained using the HPA-SSP method. The presence of mutations was analyzed by sequencing the exons of the ITGB3 and ITGA2B genes. The target gene of ITGB3 was obtained by PCR amplification using the existing human platelet cDNA. The wild-type ITGB3 eukaryotic expression vector was constructed by TA cloning technology. The 598G>A mutant ITGB3 eukaryotic expression vector was obtained by point mutation, and the plasmid DNA was co-transfected with that of ITGA2B (αⅡb) into HEK293 cells. The transfected cells stably expressing GP Ⅱb/Ⅲa were screened and obtained. The expression of GP Ⅱb/Ⅲa in 598G>A mutant transfected cells and the presence of antibodies against this mutation in the serum of mother were detected by flow cytometry and MAIPA. Results: Antibodies against HLA-class Ⅰ and GP Ⅱb/Ⅲa glycoproteins were detected in the serum of the neonate's mother, and subsequent HLA antibody-specific testing confirmed the presence of antibodies against HLA-B 57∶01 and A 02∶05. ITGB3 sequencing showed that the neonate and her father carried the c.598G>A point mutation, which results in the change of glutamate to lysine at position 200. Antibodies against GP Ⅱb/Ⅲa glycoproteins were not detected using constructed c.598G>A mutant transfected cells reacted with the maternal serum. Conclusion: The in vitro expression and analysis of the ITGB3 c.598G>A mutation did not support a role for this mutation in the pathogenesis of FNAIT. The establishment of this method facilitates the discovery of new platelet low-frequency antigens, and provides a theoretical foundation for the detection of antibodies against platelet antigens associated with patients with adverse pregnancy and childbirth histories.