BACKGROUND:Nano bone putty and bone cement injection are two common methods to strengthen the fixation of pedicle screws, but there are relatively few reports on the comparison of their strengthening effects. OBJECTIVE:To compare the biomechanical characteristics of bone cement and nano bone putty strengthening pedicle screw implantation in the fixation of osteoporotic vertebral body. METHODS: Totaly 24 human cadaveric pedicles were obtained, which were al in line with osteoporosis standards, and randomly divided into 3 groups: control group (only implanted pedicle screws), bone cement group (first injected bone cement in the nail channel, and then implanted pedicle screws) and nano bone putty group (first injected nano bone putty in the nail channel, and then implanted pedicle screws). After 2 hours of implantation, the maximum axial pulout strength and the maximum rotation torque of specimens in each group were determined. RESULTS AND CONCLUSION:The maximum axial pulout strength and maximum rotation torque of the bone cement and the nano bone putty groups were greater than those of the control group (P < 0.05), and the maximum axial pulout strength and the maximum rotation torque of the bone cement group were greater than those of the nano bone putty group (P < 0.05). These results demonstrate that the maximum axial pulout strength and the maximum rotation torque of pedicle screw implantation in the fixation of osteoporotic vertebral body can be effectively improved by injection of bone cement and nano bone putty, and the strengthening effect of bone cement is more obvious. 

[Objective] To evaluate the biocompatibility in vivo of Mg alloy AZ91D(AZ0),Mg-Mn-Ce(RE0)and their step anodizational materials(AZ1,AZ2,AZ3,RE1,RE2,RE3)by the experiments of intradermal stimulus and sensitivity response.[Methods]According toGB/T 16886.10-1997 Biological Evaluation of Medical Apparatus and Instrument,compared with normal sodium,pure magnesium and medical Ti-6Al-7Nb,the leaching liquor were injected into cutis to evaluate stimulus response,to evaluate sensitivity response by injection and illinition.[Results]RE2 could not prepare leaching liquor,it's kicked out.Intradermal stimulus response:normal sodium,Ti-6A1-7Nb,AZ1,AZ3 groups inflammation responded as degree I,scored 0.The others inflammation responded as degree Ⅱ,scored 1.Sensitivity response:formaldehyde group inflammation responded as degree IV,erythema and edema were degree IV.Normal sodium group inflammation responded as degree I,erythema and edema were degree 0.Ti-6Al-7Nb,AZ1,AZ3 groups inflammation responded as degree Ⅱ,erythema and edema were degree 1.The others inflammation responses were degree Ⅲ,erythema and edema were degree Ⅱ.[Conclusion]The new kinds of magnesium alloy AZ1,AZ3 possesses good preliminary biocompatibility in vivo,so it is very possible to be a new type of bone surgery implant material.

[ ABSTRACT] AIM:To determine the role of transcription factor Bach1 in the functions of human microvascular en-dothelial cells ( HMVECs ) .METHODS: Bach1 siRNA was transfected into HMVECs to knock down the expression of Bach1.In vitro endothelial cell tube formation assay in Matrigel culture was used as a surrogate assay for angiogenic poten-tial.Migration of HMVECs was determined by using Transwell chambers.Cell proliferation was measured by CCK-8 assay. Real-time PCR, Western blotting, and ELISA were employed to determine mRNA expression and protein level.Reporter as-say was performed to determine vascular endothelial growth factor ( VEGF) transcriptional activity.RESULTS:Knockdown of Bach1 expression in HMVECs led to an increase in the tube formation and increased endothelial cell migration ability, whereas it has little effect on cell proliferation.Bach1 silencing increased the mRNA and protein expression of heme oxygen-ase-1 (HO-1), and enhanced VEGF transcriptional activation, and mRNA and protein expression.CONCLUSION:Bach1 silencing increases HO-1 and VEGF expression, thus promoting the cell migration and tube formation of HMVECs, indicating that Bach1 is a repressor for angiogenesis.

Objective To analyze the possible reasons of failed surgical treatment of acetabular fractures. Methods Various methods were used for positive patient identification, including according to Matta's X-ray assessment and Merle d'Aubigne & Postel hip function score of clinical standards for classification of acetabular fracture reduction surgery were not satisfied or not carried out a reduction and fixation,the clinical evaluation of hip joint as a "bad", occurrence of femoral head subluxation or dislocation, femoral head necrosis and other serious complications. From February 2000 to February 2008, 22 patients including 14 males and 8 females with an average age of 38.6 years (range, 18-72 years) were considered as failed cases. Results 45.5% of these cases were posterior wall fractures which were not given any fixation, 27.3% of them were posterior column fractures which were not fixed, 13.6% of them whose reduction and fixation of anterior wall fractures were not satisfied, and 9.1% of them were anterior column fractures which needed fixation. One case should take open reduction and iternal fixation instead of THA. The rate of misdiagnosis and mistaken diagnosis were 90% if only X-ray evaluation was made and this rate decreased to 8.3% if computed tomography was taken. The rate of wrong selection of operative approach was 100% in 10 cases of misdiagnosis, and which was 58.3% in 12 cases of correct diagnosis. In the 5 patients with correct diagnosis and selection of operative approach, the reasons of failed surgical treatment were due to imperfect surgical skills in 3 cases, and inappropriate fixation patterns in 2 cases. Conclusion The causes of the failure of surgical treatment for acetabular fracture might include preoperative missed diagnosis and misdiagnose, inappropriate approach, and an unreasonable internal fixation with unskillful technique.

Objective To evaluate the effect of preoperative oral rehydration on postoperative recovery in patients undergoing laparoscopic radical resection of colorectal cancer.Methods Eighty patients of both sexes,aged 18-64 yr,with body mass index of 18-24 kg/m2,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,scheduled for elective radical resection of colorectal cancer,were randomly divided into either routine fluid replacement group (group R) or oral rehydration group (group O) with 40 patients in each group.Fasting for solid food was performed at 8 h before surgery and for water at 6 h before surgery,and fluid was replaced according to the volume expansion during induction and 4-2-1 formula in group R.In group O,multivitamin drinks containing sugar and electrolyte was given orally according to the fasting time:12-15 ml/kg at 8 h of fasting,15-20 ml/kg at 8-12 h of fasting,with the total volume not exceeding 1 200 ml,300 ml at 3 h before surgery,and the rest of fluid was given at different times the night before surgery,and fluid replacement 1 200 ml was performed according to the basic requirement of patients and intraoperative fluid loss.Fluid replacement was maintained at a rate of 1.5 ml · kg-1 · h-1 on the day of surgery in two groups.The volume of oral fluid intake,intraoperative net volume of fluid intake and volume of intravenously given fluid on the day of surgery were recorded.The time of surgery,emergence time,time to first flatus,time to first liquid diet,first ambulation time and length of postoperative hospital stay were recorded.The development of postoperative nausea and vomiting and hypotension was recorded.Peripheral venous blood samples were collected on the morning of day 2 after admission to hospital,the day of surgery and day 1 after surgery (T0-2) for determination of the fasting blood glucose and insulin concentrations,and insulin resistance index was calculated.Results Thirty-seven and 35 patients were included in R and O groups,respectively.Compared with group R,the intraoperative net volume of fluid intake and volume of intravenously given fluid on the day of surgery were significantly decreased,fasting blood glucose and insulin concentrations and insulin resistance index were decreased,and the time to first flatus,time to first liquid diet and length of postoperative hospital stay were shortened in group O (P＜0.05).Conclusion Preoperative oral rehydration can promote postoperative recovery,which may be related to mitigating insulin resistance in patients undergoing laparoscopic radical resection of colorectal cancer.