BACKGROUND:After spinal cord injury, endogenous neural stem cel s are activated to proliferate and migrate to repair damaged tissue. As a clinical medicine, methylprednisolone shows a lot of functions, but its effects on endogenous neural stem cel s are stil unknown.
OBJECTIVE:To explore the effects of methylprednisolone on the proliferation and migration of endogenous neural stem cel s after spinal cord injury.
METHODS:Seventy-five Sprague-Dawley rats were used to make animal models of T10 complete paraplegia using Al en’s method, and randomized into methylprednisolone, normal saline and model groups. Rats in these three groups were given intraperitoneal injection of 1 g/L methylprednisolone solution at a dose of 30 mg/kg for 10 minutes and at a dose of 5.4 mg/kg/h for 23 hours, given intraperitoneal injection of normal saline at the same dose and given no treatment, respectively. Neurological and motor functions were assessed by somatosensory evoked potential and Basso Beattie Bresnahan scores at 7, 14, 21, 28 days after spinal cord injury. BrdU and Nestin staining of the injured spinal cord segment was conducted.
RESULTS AND CONCLUSION:A large amount of BrdU-and Nestin-positive cel s were visible in al the groups, and the number of these cel s reached the peach at 14 days after spinal cord injury. Methylprednisolone was found to inhibit BrdU-, Nestin-or double-positive cel s, indicating methylprednisolone can inhibit the proliferation and migration of endogenous neural stem cel s. The results of Basso Beattie Bresnahan scores showed no notable improvement in the motor function of the limbs. Methylprednisolone also showed no significant effects on the motor evoked potential latency, but promoted nerve conduction recovery. Al these findings indicate that methylprednisolone has some hindering effects on spinal cord repair by inhibiting the proliferation and migration of endogenous neural stem cel s after spinal cord injury.

BACKGROUND:Plate fixation or intramedulary fixation for clavicle fractures has remained a matter of debate. At present, there is a need for a higher level of evidence to evaluate the advantages and disadvantages of two different surgical methods.
OBJECTIVE:To assess the clinical efficacy of intramedulary fixationversusplate fixation in the treatment of clavicle fractures.
METHODS:We conducted a computerized search of the electronic databases like Cochrane Library, PubMed, Embase, OVID, CBM, CNKI, Wanfang and VIP for relevant randomized controled trials on plate fixation or intramedulary fixation for clavicle fractures. The quality of the included studies was independently assessed with RevMan 5.3 software. The meta-analysis was performed in Stata 13.0.
RESULTS AND CONCLUSION:Eight randomized controlled trials with 527 patients were included in this meta-analysis. The meta-analysis results showed union time, surgery time, incision length, hospital stay and infection rate were less in the intramedullary fixation group than in the plate fixation group (P< 0.05). No significant difference in shoulder function score, upper limb function score, fracture nonunion and refracture was determined between the two groups (P< 0.05). The current evidences suggested that intramedullary fixation is the optimum choice in the treatment of clavicle fractures.

Objective To investigate the in vitro cytocompatibility of three-dimensional porous scaffolds of poly-D,L-lactic acid (PDLLA) and discuss the feasibility of PDLLA as a scaffold for bone tissue engineering.Methods BMSCs of the third passage were seeded on osteogenetic differentiation medium or culture medium containing 20％ volume fraction degraded liquid (PDLLA degradation liquid of 0,3,6,9,and 12 weeks) according to the random number table.Osteogenetic differentiation medium or culture medium without PDLLA was used as controls.Cell viability,cytotoxicity,and osteogenic differentiation were detected for study on cytocompatibility of PDLLA.Scanning electron microscopy was used to observe the growth of BMSCs on the surface of PDLLA scaffolds.Results PDLLA scaffolds presented no significant cytotoxic on the growth of BMSCs.PDLLA scaffolds had no negative effect on cell viability compared with the controls (t3 =-0.441,P =0.671; t6 =1.596,P =0.154; t9 =-0.492,P =0.636; t12 =-1.135,P=0.283).ALP staining and calcium nodule staining were positive and there were no significant differences in ALP and collagen Ⅰ protein quantitative detection compared with the controls.BMSCs grew well on the inner surface of the PDLLA three-dimensional porous scaffolds.Conclusion Three-dimensional porous scaffolds of PDLLA present good cytocompatibility in vitro and can be used as bone tissue engineering scaffolds for subsequent in vivo research.

Objective To investigate the therapeutic effects of nano-hydroxyapatite/polyamide 66/platelet-rich plasma com-pound(n-HA/PA66/PRP)on the recovery of rabbit femur bone defect.Methods 40 New Zealand rabbits were artificially made to be bone defect by resecting the 1 cm substantia ossea with periosteum of femur,and were divided into two groups averagely depen-ding on implanted materials:experimental group(n-HA/PA66/PRP),control group (n-HA/PA66).Every five rabbits were sacri-ficed on week 2,4,8,12,and the femur healing status was observed by X ray,histology,and immunohistochemistry.Results No rabbit was infected or died,no implantation objects dropped.Gross observation,X-ray result and histology results demonstrated that the experimental group began to have a new bone tissue at 2 weeks after the operation,with the extension of time,the experimental group new bone growth speed and the quantity was better than the control group.The Lane-Sandhu method X-ray score showed that the experimental group (6.80±2.05)points and the control group(4.20±1.30)points at 12 weeks after the operation,and there were significant differences between two groups(P <0.05).Immunohistochemistry indicated that expression intensity of Vas-cular endothelial growth factor at 2 weeks and 4 weeks were significant differences between two groups(P <0.05),but there was no significant difference at 8 weeks and 12 weeks (P >0.05).Conclusion PRP combined with n-HA/PA66 artificial bone could accel-erate the healing of bone defect,and the effect of repair of bone defect is better than that of n-HA/PA66 artificial bone in the early.

Objective To compare the clinical outcomes of transforaminal lumbar interbody fusion (TLIF) through Wiltse approach and posterior midline approach in the treatment of degenerative lumbar spondylolisthesis.Methods A total of 37 patients with degenerative lumbar spondylolisthesis were treated between March 2008 and March 2010,including 23 patients managed by TLIF via posterior midline approach ( posterior midline approach group) and 14 by TLIF via Wiltse approach ( Wiltse approach group).The Japanese Orthopaedic Association (JOA) score and visual ltanalogue scale (VAS) before and after operation,and the interbody fusion condition in both the Wiltse approach group and posterior midline approach group were reviewed and the clinical outcomes of both groups were compared.Results The follow-up lasted for 6-26 months ( mean,15.7 months),during which both groups had obvious relief in clinical symptoms like pain of waist and legs.X-ray photographs showed good spondylolisthesis reduction and interbody fusion,with no loosening or breakage of the internal fixators.The fusion rate of Wiltse approach group and posterior midline approach group at the last follow-up were 86％ and 87％,respectively.The operation time of Wiltse approach group and posterior midline approach group was ( 117.8 +25.6) minutes and ( 128.5 ± 38.7 ) minutes respectively ( P ＞ 0.05 ).The intra-operative blood loss of Wiltse approach group and posterior midline approach group was (203.5 ± 16.4) ml and (284.4 ±27.6) ml respectively (P ＜0.05).Both groups presented significant decrease of JOA score post-opera-tively (P ＜ 0.05).Also,the two groups sbowed significant difference concerning the VAS score in low back pain one week post-operatively (P ＜ 0.05),but no significant difference in terms of VAS score in leg pain at one week after operation (P＜0.05) and VAS score in pain of low back and legs at the final follow-up ( P ＞0.05).Conclusions In the management of lumbar spondylolisthesis,TLIF via Wiltse approach and via posterior midline approach can both achieve satisfactory interbody fusion rate and clinical outcomes,but the Wiltse approach results in relatively less intra-operative blood loss and faster postoperative recovery.

Objective To compare the effect of anterior and superior reconstruction plate internal fixation in treatment of middle clavicular fractures in the old patients.Methods Thirty-nine old patients with middle clavicular fractures received anterior and superior reconstruction plate internal fixation treatment,respectively.There were 19 males and 20 females at average age of 66.7 years.The operation time,intraoperative blood loss and healing time were observed and compared in two groups.According to the Constant scoring system,shoulder functional evaluation was made at half a year after operation and the latest follow-up.Results All the patients were followed up for 10-32 months (average 18.7 months).Of the two groups,there was no statistical significance in aspects of healing time and Constant score at half a year after operation and the latest follow-up ( P ＞0.05 ).The complication of superior reconstruction plate internal fixation group was significant higher than that of anterior reconstruction plate internal fixation group,while the anterior reconstruction plate internal fixation group had shorter operation time and less intraoperative blood loss in comparison with the superior reconstruction plate internal fixation group ( P ＜ 0.05).Conclusion As for the middle clavicular fractures in the old patients,both anterior and superior reconstruction plate internal fixation can obtain satisfactory curative effect.With shorter operation time,less intraoperative bleeding and less complications,anterior reconstruction plate internal fixation is a much reliable treatment for middle clavicle fractures in the old patients and deserves wider application.

Objective To evaluate the clinical effect of limited open reduction, poking reduction and QWIX cannulated screw internal fixation in treatment of posterior malleolar fracture. Methods A total of 14 patients with posterior malleolar fracture were treated by limited open reduction, poking reduction and QWIX cannulated screw internal fixation. Injury causes included traffic accidents in five patients, fall from height injury in four and inversion sprain in five. According to fracture type classification methods of Weber and Danis, there were two patients with type A3, seven with type B3 and five with type C3. Func-tional exercise was carried out based on postoperative exercise plan. Regular follow-up was performed to e-valuate the functional recovery of the ankle joint. Results All patients were followed up for 6-18 months (average 9.5 months). One patient with sural nerve injury returned to normal after six months. Twelve pa-tients showed excellent range of motion of the ankle joint and normal gait three months after operation. In 12 patients, dorsiflexion of the ankle joint was > 20° and plantar flexion > 40° six months after operation, which was approximately similar to contralateral normal ankle joint. The ankle joint function of all patients returned to normal six months after operation. According to Baird-Jackson ankle joint function evaluation, the result was excellent in 12 patients, good in one and fair in one, with excellence rate of 93%. Con-clusion The limited open reduction, poking reduction and internal fixation of QWIX caunulated screw are effective method for treatment of posterior malleolar fractures.

BACKGROUND: An ideal repairing material characterizes by both great biocompatibility and osteogenesis ability. Any biomaterials should meet excellent biological security and biocompatibility prior to clinical application.OBJECTIVE: To evaluate the biocompatibility and the biological security of the TiO_2-Ag-nano-hydroxyapatite/polyamide66 (TiO_2-Ag-nHA/PA66) composite.DESIGN, TIME AND SETTING: A randomized controlled duplicated design was performed in Chongqing Medical University from July 2008 to July 2009.MATERIALS: A total of 40 Kunming mice aged 3 weeks and of clean grade and 32 healthy adult New Zealand rabbits were provided by Experimental Animal Center of Chongqing Medical University. TiO_2-Ag-nHA/PA66 composite powder (10 g),TiO_2-Ag-nHA/PA66 composites (n=32, 5 mm ×25 mm), and TiO_2-Ag-nHA/PA66 composites (n=32, 3 mm × 5 mm) were provided by Research Center of Nano-Biomaterials of Sichuan University.METHODS: General toxicity test: Forty mice were randomly divided into experimental and control groups. Composite powder was used to prepare leaching liquor which was treated on experimental mice by an intraperitoneal injection. While, an equal amount saline was inserted into the control mice. Intramuscular implanting test: The 16 rabbits were randomly divided into experimental and control groups. Two TiO_2-Ag-nHA/PA66 composite (5 mm × 25 mm) were implanted into left and right erector spinae, respectively. A similar surgery with the exception of implantation was performed on the control rabbits. Intrabony implanting test: The resting 16 rabbits were implanted one TiO_2-Ag-nHA/PA66 composite (3 mm × 5 mm) into left and right lateral epicondyle, respectively. Hemolytic test: A 8-mL anti-coagulation blood was obtained and added with composite powder (0.1,0.15, and 0.2 g).MAIN OUTCOME MEASURES: Biocompatibility and biological security of TiO_2-Ag-nHA/PA66 composite.RESULTS: General toxicity test demonstrated that mice in the two groups had good activity and eating, normal breathing, stable body mass, no paralysis, convulsion, and death. Intramuscular implanting test and intrabony implanting test showed that there was no significant difference in levels of alanine aminotransferase, aspartate transaminase, urea nitrogen, and creatinine and leukocyte numbers between the two groups before implantation and at day 4,1 week, and 2 weeks after implantation (P> 0.05).In particular, there was no significant difference in the experimental group at varying time points (P> 0.05). Intramuscular implanting test indicated that tissue sections in the experimental group displayed coated tissue of materials. The inflammatory variation in the experimental group was generally similar to that in the control group. Intrabony implanting test indicated that tissue sections in the experimental group displayed new bone formation. Hemolytic test suggested that hemolytic ratio of three varying concentrations of TiOrAg-nHA/PA66 composites was less than 5%, which met the normal criterion.CONCLUSION: TiO_2-Ag-nHA/PA66 composite has a good biocompatibility and biological security.

Objective To analyze clinical manifestation,diagnosis and treatment of 8 patients with gas gangrene in Wenchuan earthquake.Methods Eight patients with gas gangrene in Wenchuan earthquake were selected for analysis on their clinical manifestations.We finally diagnosed gas gangrene based on patients'clinical manifestation and the cultured ciostridium in the focus of infection.All the patients were treated with antibiotics,repeated surgical debridement,hyperbaric oxygen and nutritional support.Results Most patients had no erepitation of the extremities but found gas in interstice of tissues identified by X-ray,B-ultrasound and CT scanning.Film preparation of efflusion of all patients showed clostridium and bacterial culture manifested mainly perfringens.Most patients were demonstrated to be with polyinfection.In addition,all patients were characterized by pitchy necrotic tissues,effusion,systemic decrease of red blood cells,increase of white blood cells and platelet.No death or amputation occurred under active combined therapy.Conciusions Earthquake induces mainly open trauma often combined with mixed infection,when gas gangrene is one of main special infections.The predominant combined therapies include utility of antibiotics and thorough surgical debridement,while hyperbaric oxygen and nutritional support are important and effective adjunctive therapies.

Objective To analyze the clinical features of patients with open injuries combined with infections in Chinese Wenchuan earthquake and summarize the therapeutic experience. Methods An analysis was done on 54 patients with open injuries combined with infection transferred to our depart-ment from May 13, 2008 to June 10, 2008. Thorough debridement was performed based on general sup-porting management and anti-bacterial thempies done on the basis of results of bacteria culture and sus-ceptibility test. In the meantime, other managements including high-pressure oxygen therapy and external fixation were done for open fractures. Results Infection could be found in all open injuries, primarily combined infections with G+ coccus and G- bacillus or anaerobic. Moreover, most of the patients were infected by anaerobia. Of all, 1 patient with amputation received multiple debridement and repair because of severe infection of the amputation site and no death occurred. All patients recovered uneventfully, with sound wound healing, except for 2 patients. External fixation was stable and in good position. Conclu-sions The repeated and thorough debridement and the timely closure of wounds on the basis of energeti-cally anti-infection measures are key to diminishing the mortality rate and mutilation rate. Appropriate ad-junctive therapy can dramatically improve the curative effect.