Objective To compare the clinical outcome of intramedullary nail with locking plate in the treatment of two-part proximal humerus fractures.Methods PubMed,SpringerLink,EMBASE,The Cochrane Library,Medline,Science Direct,CNKI,Wanfang Data and VIP database were searched for relevant studies comparing intramedullary nailing and locking plate fixation of two-part proximal humerus fractures.A meta-analysis of the two methods was conducted using the RevMan 5.0.Differences between the two methods were compared with respect to operation time,intraoperative bleeding,bone union time,Constant score and postoperative complication incidence.Results Seven studies were included in the meta-analysis,with 136 patients treated with intramedullary nail and 159 patients treated with locking plate.Intramedullary nailing showed advantages over locking plate fixation with regards to operation time (WMD =-27.71,95％ CI-36.07--19.35,P ＜ 0.05),intraoperative blood loss (WMD =-114.18,95％ CI-169.91--58.45,P ＜ 0.01) and bone union time (WMD =-2.91,95％ CI-5.80--0.01,P ＜ 0.05).While the two methods showed no significant differences in Constant score (WMD =-2.84,95 ％ CI-5.90--0.22,P ＞ 0.05) and postoperative complication incidence (OR =0.89,95％ CI 0.43-1.84,P ＞ 0.05).Conclusion Intramedullary nail is superior to locking plate in operation time,intraoperative blood loss and bone union time for the treatment of two-part proximal humerus fractures,but the two methods are similar in Constant score and postoperative complications rate.

Objective To determine the gastric emptying time for liquids in the healthy volunteers by magnetic resonance imaging (MRI) and to provide a reference for reasonable preoperative fasting time.Methods Nineteen healthy volunteers of both sexes,of ASA physical status Ⅰ or Ⅱ,aged 20-60 yr,were enrolled in the study.The volunteers were fasted from the intake of liquids or solids starting from 22:00 the night before the trial,and 12.5％ carbohydrate solution 400 ml containing 40 g maltodextrin and 10 g sucrose was given orally.MRI was performed to measure the baseline gastric fluid volume at 8:00 on the day of the trial (T0).The gastric fluid volume was measured immediately after administration of the oral solution,and then measured every 25 min until the gastric fluid volume was returned to the baseline before administration of the oral solution or to ＜25 ml,and was recorded as T25,T50,T75,T100,et al.The gastric fluid volume was drawn using a computer to obtain the curve for gastric emptying.The gastric half and total emptying time was calculated using the curves.Results The gastric half emptying time was (32± 12) min,and the gastric total emptying time was (99±22) min in the volunteers.Compared with those at Tb,the gastric fluid volume was significantly increased at T25,T50,T75,T100,and no significant change was found in gastric fluid volume at T125,T150and T175.Conclusion After oral intake of liquids,the gastric emptying time is about 2 h,indicating that the preoperative fasting time for liquids can be shortened to 2 h before anesthesia in the healthy volunteers.

Objective : To investigate the effect of silencing histone deacetylase 9 (HDAC9) expression on the proliferation and osteogenic differentiation of periodontal ligament stem cells (PDLSCs). Methods: PDLSCs were isolated, cultured and identified in vitro. An siRNA construct specific for HDAC9 was transfected into PDLSCs (siHDAC9 group), and a nontargeting siRNA was used as a control (siNC group). The interference effect was determined by qRT-PCR. The cell cycle progression of PDLSCs was detected using flow cytometry. The proliferation activity of PDLSCs was detected via CCK-8 assay. Western blotting was used to detect the protein expression of proliferating cell nuclear antigen (PCNA). The mRNA expression of runt-related transcription factor 2 (RUNX2) and alkaline phosphatase (ALP) was investigated by qRT-PCR. The protein expression of RUNX2 was detected by western blotting. In addition, the formation of mineralized nodules was assessed by alizarin red staining. Results: Compared with that in the siNC group, the mRNA expression of HDAC9 in the siHDAC9 group was lower (P < 0.01). Moreover, compared with those in the siNC group, the proliferation index (P<0.01), proliferation activity (P<0.05) and protein expression of PCNA (P<0.01) in the siHDAC9 group were all increased. Compared with the siNC group, the siHDAC9 group exhibited higher mRNA expression of RUNX2 and ALP (P < 0.05), and the protein expression of RUNX2 showed the same results (P < 0.01). The results of alizarin red staining showed that compared to the siNC group, the siHDAC9 group formed more mineralized nodules. Conclusion Silencing HDAC9 expression can promote the proliferation and osteogenic differentiation of PDLSCs.