Methylation recognition protein YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) regulates the proliferation, migration and invasion of osteosarcoma by regulating m6A level of CCR4-NOT transcription complex subunit 7 (CNOT7).

N6-methyladenosine (m6A) is one of the most significant modifications in human mRNAs. Emerging evidence indicates that m6A participates in the initiation and development of malignant tumors. Nevertheless, the biological roles and mechanism of m6A in osteosarcoma (OS) remain unclear. The purpose of this study was to investigate the role and mechanism of the methylation recognition protein-YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) in OS. The YTHDF1 expression in OS was detected by qRT-PCR and Western blot assay. M6A quantification was utilized to measure the methylation level of OS. Cell counting kit-8 (CCK8), 5-Ethynyl-2'-deoxyuridine (EdU) assay and transwell experiments were conducted to confirm the biological effects of YTHDF1 on OS cells. The bioinformatics websites and in vitro assays were conducted to analyze the downstream targets of YTHDF1 was upregulated in OS tissues at mRNA and protein level. The results showed that the expression level of YTHDF1 might be closely associated with the poor prognosis for OS patients. Inhibition of YTHDF1 could suppress the proliferation, migration and invasion of the OS cells. Moreover, we found that CCR4-NOT transcription complex subunit 7 (CNOT7) might be the potential target of YTHDF1, which was upregulated in OS tissues. YTHDF1 could recognize the m6A sites of CONT7 and promote its expression in an m6A manner. Moreover, methyltransferase-like 3 (METTL3) could promote the m6A level of CONT7. YTHDF1 was upregulated in OS and could promote cell proliferation, migration and invasion. The METTL3-CONT7-YTHDF1 regulatory axis might be the potential target for the prognosis and therapy of OS.

Effectiveness and safety of tranexamic acid for total knee arthroplasty: a prospective randomized controlled trial.

BACKGROUND: Total knee arthroplasty (TKA) is associated with significant perioperative blood loss and need for transfusion. This study aimed to evaluate the effectiveness and safety of tranexamic acid (TXA) to reduce perioperative blood loss in patients receiving TKA. MATERIAL AND METHODS: A total of 92 patients who accepted unilateral TKA from May 2012 to May 2013 randomly received either 15 mg/kg TXA in 100 mL normal saline solution (TXA group, n=46) or the same amount of normal saline solution (placebo group, n=46) at 15 min before the tourniquet was loosened. The following data were recorded: intraoperative blood loss; post-operative drainage at 12 h; total drainage amount; hidden blood loss; total blood loss; transfusion volumes; number of transfusions; post-operative hemoglobin at 1, 3, and 5 days; D-dimer; number of lower limb ecchymoses; and deep vein thrombosis (DVT). RESULTS: A total of 81 patients were available for analysis (TXA group, n=41; placebo group, n=40). Post-operative12-h drainage, post-operative 24-h D-dimer values, total drainage volume, hidden blood loss, total blood loss, and the rate of postoperative ecchymosis were lower in the TXA group than in the placebo group (p<0.05). The post-operative 3-day Hgb was higher in the TXA group than in the placebo group (p=0.000). The rate of transfusion and DVT was similar in both groups (n.s.). CONCLUSIONS: Perioperative blood loss could be reduced after TKA by intravenously injecting 15 mg/kg TXA at 15 min before the tourniquet was loosened. The application of TXA is not associated with increased risk of DVT.

[Total hip surface replacement arthroplasty: report of 31 cases].

OBJECTIVE: To introduce the technique of total hip surface replacement, evaluate the early results and review the factors which affect the results. METHODS: From October 2000 to January 2005, 31 patients (37 hips) with osteonecrosis, osteoarthritis, hip dysplasia, ankylosing spondylitis were treated with the total hip surface replacement. Among them, 15 were male, and 16 were female, with an average age of 42 years (range from 23 - 65 years). All the 31 patients had the indications for hip surface replacement. Standard operation technique which was brought forth by Amstutz and Nelson was employed, and all patients were followed up after operation. RESULTS: Patients were followed up for an average period of 42 months (3 - 51 months). There were no femoral neck fracture, no dislocation, no infection in all patients. Radiolucent line existed around acetabular prosthesis in 1 hip and another hip had been revised because the prosthesis of femoral head was in incorrect situation. The average Harris hip score improved significantly from 30 to 90, and the score was 93 in the latest follow-up. Based on Harris system, 35 hips were excellent, 1 hip good, and 1 hip fail. CONCLUSIONS: The total hip surface replacement is an effective solution for the problem of the patients with osteonecrosis of the femoral head, osteoarthritis, hip dysplasia and ankylosing spondylitis. The short-term results are satisfied.