ObjectiveTo construct a prokaryotic expression strain of Staphylococcus aureus fibronectin binding protein A (FnBPA) r10-11 truncated fusion protein, and explore the immunogenicity of FnBPAr10-11. MethodsPloymerase chain reaction (PCR) amplification was carried out from the whole genome sequence of Staphylococcus aureus Newman strain by recombinant PCR technique. The amplified product was purified and transformed into Escherichia coli DH5α for cloning. The recombinant plasmid was extracted and identified by double enzyme digestion. The recovered fragment was ligated into the pET-32a plasmid and transformed into Escherichia coli BL21 (DE3) for prokaryotic expression. The FnBPAr10-11 was purified by HIS protein purification column, identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and used to immunize mice, and the mice were divided into phosphate buffered saline (PBS) group, FnBPA group, and FnBPAr10-11 group. The serum levels of immunoglobulin G (IgG) and cytokines, and the immune protection rate of the mice were detected. ResultsSDS-PAGE result showed that the relative molecular mass of the protein was about 33.1×103. The titers of IgG antibody in FnBPAr10-11 group and FnBPA group reached 1∶128 000, and were significantly different compared with PBS group (P<0.05). The cytokine level in FnBPAr10-11 group was not significantly different compared with that in FnBPA group, and they were extremely significant (P<0.01) compared with that in PBS group. The immuno-protective effect of the FnBPAr10-11 group was over 50%. ConclusionsThe prokaryotic expression strain of Staphylococcus aureu FnBPAr10-11 truncated fusion protein was successfully constructed. The truncated protein has good immunogenicity.
ObjectiveTo explore the efficacy and safety of intravenous injection of tranexamic acid (TXA) combined with local use of TXA cocktail in intertrochanteric fracture fixation with proximal femoral nail antirotation (PFNA).MethodsPatients with intertrochanteric fractures who underwent close reduction and internal fixation with PFNA between February 2018 and March 2019 were enrolled in the study. Among them, 45 patients who met the selection criteria were included in the study and randomly allocated into 3 groups (n=15). The patients in group A were not received TXA during perioperative period. The patients were intravenously injected of 1.0 g TXA before operation in group B and combined with local use of TXA cocktail during operation in group C. There was no significant difference in the age, gender, body mass index, fracture classification, disease duration, and complications between groups (P>0.05). The perioperative blood loss and blood transfusion rate, the visual analogue scale (VAS) score before operation and at 12, 24, and 48 hours after operation, the levels of prostaglandin E2 (PGE2) and bradykinin (BK) before operation and at 1 and 3 days after operation, postoperative complications, and the maximum amplitude (MA) of thromboelastogram were recorded and compared between groups.ResultsThe total blood loss, hidden blood loss, and visible blood loss were significantly lower in groups B and C than those in group A (P<0.05), and the total blood loss and hidden blood loss were significantly lower in group C than those in group B (P<0.05). There was no significant difference in the blood transfusion rate, preoperative VAS scores and the levels of PGE2 and BK between groups (P>0.05). The postoperative VAS scores and the levels of PGE2 and BK were significantly lower in group C than in groups A and B (P<0.05). There was no significant difference in pre- and post-operative MA of thromboelastogram between groups (P>0.05). The incidences of postoperative complications were 33.33% (5/15), 20.00% (3/15), and 13.33% (2/15) in groups A, B, and C, respectively, with no significant difference between groups (χ2=1.721, P=0.550).ConclusionFor intertrochanteric fractures, application of intravenous injection of TXA combined with local use of TXA cocktail in PFNA fixation can reduce perioperative blood loss, relieve pain after operation, and do not increase the risk of complications.