Exosomes are secreted by living cells,which have the lipid bilayer and a large number of inclusions.We have found that exosomes derived from tumor cells play a crucial role in the development of tumor.Tumor-derived exosomes not only act as the messenger between tumor cells,but also perform as a carrier that affects the normal cells far away.Moreover,it has been reported to play positive role in the proliferation,differentiation,metastasis and immune resistance of tumor cells.

BACKGROUND:In the total hip arthroplasty, intravenous and topical tranexamic acid can significantly reduce the perioperative blood loss and blood transfusion rate, but at present, the clinical application of tranexamic acid is stil controversial. OBJECTIVE:Cochrane system evaluation method is applied on the efficacy and safety of intravenous combined with topical application versus single-dose intravenous application of tranexamic acid in the total hip arthroplasty. METHODS:We searched the Cochrane Library, PubMed, Ovid, EMBASE, CBM, Wanfang, VIP and CNKI database, from inception to July 2016 and retrieval of randomized control ed trials concerning intravenous combined with topical application and single dose intravenous application of tranexamic acid during total hip arthroplasty. Total blood loss, intraoperative blood loss, postoperative blood loss, blood transfusion rate, thrombosis, operation time, and length of hospital stay were analyzed by meta-analysis. RESULTS AND CONCLUSION:(1) There were seven randomized control ed trials with 620 patients. (2) Meta-analysis results indicated that total blood loss, intraoperative blood loss, postoperative blood loss, and blood transfusion rate were significantly better in the combination group than in the single dose group (P<0.05). There were no significant differences in thrombosis, operation time, and length of hospital stay between the two methods (P>0.05). (3) These results suggested that compared with the single dose of intravenous application, intravenous combined with topical application, can significantly reduce the loss of blood volume and blood transfusion rate and did not increase the rate of thrombosis. Subject headings:Arthroplasty, Replacement, Hip;Tranexamic Acid;Venous Thrombosis;Hemorrhage;Tissue Engineering