Objective To study the method of isolating and culturing stem cells from rat adipose tissue and to determine if adipose-derived stem cells(ADSCs)harvest from rat could differentiate into osteogenic and chondrogenic in vitro.Methods ADSCs were isolated from rat inguinal fat pads after extensive washing with phosphate-derived saline and digesting with collagenase.After primary culture in control medium and expanded to two passages,the cells were incubated in either an osteogenic medium or an chondrogenic medium for 2-4 weeks to induce osteogenesis and chondrogenesis,respectively.Evidences of Osteogenic differentiation,were detected by a ALP solution,and while chondrogenic differentiation was confirmed using the histologic Alcian blue staining at acidic pH.Expressions of osteocyte and chondrocyte specific genes were confirmed by RT-PCR.Results ADSCs can be isolated from rat adipose tissue and,expanded rapidly.It exhibited a heterogeneous population of fibroblast like cells morphologically.ADSCs induced to osteogenesis were stained positively for alkaline phosphatase activity after 2 weeks and formed mineralized nodular structures,as conformed by Von kossa staining.Expression of osteocyte specific genes,such as ALP,osteopontin,osteocalcin,was detected.ALP and osteopontin,were expressed constitutively in osteogenic medium after 2 and 4 weeks of culture.Expression of osteocalcin,was induced by osteogenic growth factors at 4 weeks.Induced to chondrogenesis cells were positive of Alcian blue staining under acidic conditions and expression of aggrecan and typeⅡ/Ⅹ collagen genes.Aggrecan and typeⅡcollagen genes were abundant after 2 weeks in chondrogenic medium.TypeⅩ collagen gene was detected at 4 weeks.Conclusion Adipose-derived stem cells can be isolated from rat adipose tissue.Their biological characteristics are similar with mesenchymal stem cells(MSCs),and have the potential to differentiate into osteogenic and chondrogenic lineage.It may be an idea source of ADSCs for tissue engineering.

BACKGROUND:There are many methods to treat thoracolumbar fractures However,it remains unclear whether a simple operation to treat a thoracolumbar burst fracture can decrease the trauma and obtain better effect to avoid the enlargement of operation.OBJECTIVE:To investigate the clinical outcome of posterior short-segmental transpedicular screw system internal fixation in treatment of single-level thoracolumbar burst fracture without nerologic deficit.METHODS:A total of 186 patients with single.level thoracolumbar burst fracture but without nerologic deficit treated in the First Affiliated Hospital of Soochow University between September 2003 and January 2008,including 152 males and 34 females,aged18 10 65 years.were treated by posterior pedicle screw The intraspinal bone fragments were treated with indirect decompression.All patients were checked with radiography and CT scan before/after operation as well as before implant removal.The correction of anterior vertebral body height and the ratio of bone fragment to cross section area of spinal canal were measured.RESULT AND CONCLUSION:Compared with normal.the anterior vertebral body height was 42%before operation,98%after operation,and 98%before implant removal The ratio of bone fragment to cross section area of spinal canal was 34%before operation,13%after operation.and 8%before implant removal.Internal posterior short-segmental transpedicular screw fixation treating single-level thoracolumbar burst fracture without nerologic deficit can obtain stability of spinal column,and it is beneficial to recovery of body height,physiologic postu ral contour and canal volumn .

ObjectiveTo explore the therapeutic effect of selective antagonist-AM630 of cannabionid receptor 2 (CB2) in treatment of the titanium particles-induced inflammatory osteolysis.MethodsForty-five female BALB/c mice, 6-8 weeks old, were involved in the study, of which 15 mice were used as skull donors and the rest experimental animals were randomly divided into three groups, ie, black group, control group and treatment group, 10 mice per group.The mice model with air-pouch osteolysis induced by the titanium particles were established.The mice in the treatment group were injected with CB2 selective antagonist-AM630 (200 μg · kg-1 · d-1) intraperitoneally from two days before establishment of the air-pouch osteolysis model to two weeks after establishment of the model.Then, the mice were sacrificed and the pouch tissues were collected for molecular and histological analyses.The pouch membrane thickness and cell infiltration were tested by using computerized image analysis system and HE staining respectively.Osteoclast-like cells in the pouch membrane were determined by using tartrate-resistant acid phosphatase (TRAP) staining.Quantitative real-time polymerase chain reaction (RT-PCR) was employed to detect the mRNA levels of CB2, IL-1 β, TNF-α, receptor activator of NF-κB ligand (RANKL)and receptor activator of NF-κB (RANK).ResultsThere exhibited apparent erythematous and oedematous changes in the control group, which was mitigated around the bone implants with AM630 treatment.Quantitative image analysis of the histological sections revealed significant difference of the pouch membrane thickness among three groups, (192.2 ± 19.4)μm in control group, (88.5 ± 14.7) μm in blank group and (122.1 ± 15.2) μm in treatment group (F = 101.74, P ＜ 0.05).Intensive TRAP staining was identified much in the control group but markedly reduced after AM630 treatment in the pouch tissues.RT-PCR showed that titanium particle stimulation could enhance the expressions of CB2, IL-1 β, TNF-α, RANKL and RANK gene in the air pouch tissues.However, the mRNA levels of these genes were markedly reduced after AM630 treatment, with statistical difference compared with control group (P ＜ 0.05).ConclusionsCB2 selective antagonist AM630 can inhibit the process of titanium particlesstimulated inflammatory reaction and osteoclast activation.Therefore, CB2 represents a new suitable therapeutic candidate for the prevention and treatment of aseptic loosening of the artificial joint.

BACKGROUND:There are a variety of surgical approaches for minimally invasive total hip replacement,such as anterolateral,posterolateral and two-incision.However,it is unknown which one is more in line with the concept of minimally invasive and easy to carry out.OBJECTIVE:To observe the clinical application effect of total hip replacement using anterlateral modified Watson-Jones approach.METHODS:From January 2005 to December 2006,35 patients were performed total hip replacement with the new anterlateral approach at the Department of Orthopaedics,the First Affiliated Hospital of Soochow University,including 16 males and 19 females,aged 52-78 years,mean aged 65.9 years;the average body mass index was 24.4 kg/m~2 (19.3-30.1 kg/m~2).The length of incision,operative duration,transfusion,complications,postoperative movement,postoperative hospital stay,prosthesis position and Harris score after operation were observed.RESULTS AND CONCLUSION:The patients were followed up 6-24 months,with an average of 17.3 months.The average length of incision was 8.3 cm (7-12 cm).The mean operative duration was 92.1 minutes (70-120 minutes).The average blood transfusion was 300 mL (0-800 mL).All the patients were practice their limb muscles immediately after the operation and they were activity the day after operation under the guidance of doctor.The average postoperative hospital stay was 7.9 days (5-15days).Eleven hip pains occurred at 3 months,9 cases at 6 months and 5 cases at 12 months,the Harris scores were (79.5±4.4)points,(84.0±3.6) points,and (85.4±3.0) points,respectively.No infection,dislocation,vessel or nerve injury happened.From the follow up,all of the patients had good prosthesis position and rang of hip motion.The results revealed that the new anterolateral approach is minimally invasive total hip replacement,and the patients can recover faster via some proper exercise.

Objective To compare the outcome of proximal femoral nail antirotation (PFNA)and third generation of Gamma nail (TGN) in the treatment of femoral intertrochanteric fracture in the elderly. Methods From January 2007 to June 2008, the patients with intertrochanteric fractures were divided into PFNA group ( n = 55 ) and TGN group ( n = 52 ) randomly. The two treatment groups were comparable in aspect of general data. The clinical data of surgical trauma, complications and postoperative function of the two groups were compared in our study. Results The mean operation time was (66.6 ± 15.4) min in PFNA group and (73. 1 ± 20.8 ) min in TGN group (P ＞ 0. 05 ). The mean intraoperative blood loss differed significantly, (219.5 ± 107.5 ) ml in PFNA group compared with (269.0 ±123.9) ml in TGN group ( P ＜ 0. 05 ). The mean fluoroscopy time was ( 2.97 ± 1.14 ) min in PFNA group and (3.43 ± 1.18) min in TGN group (P＜0.05). Unilateral femoral shaft splits at the distal end of the nail was observed intra-operatively in four patients of the PFNA group and in one of the TGN group,with no statistical difference between two groups. Of all, 91 patients ( n =46 in the PFNA group and n =45 in the TGN group) were followed up for a duration of ( 17.5 ±3.69) months. There was one re-fracture and one implant failure during the follow up period in PFNA group, which was not found in TGN group. Fiftyone patients recovered to normal activity status, including 27 in the PFNA group and 24 in the TGN group,with no statistical differences. Conclusions Intertrochanteric fracture can be treated successfully with PFNA and TGN. There is no significant difference in complications and functional outcome between the two groups. However, PFNA takes advantages of less blood loss, less operative time and less fluoroscopy time over TGN.

Objective To determine the important functional units of medical endoscopes and provide a theoretical basis for improving the maintenance and repair of hospital medical equipment.Methods The units of medical endoscopes were analyzed by the failure mode effects and criticality analysis (FMECA) method to determine the important functional unit.The maintenance methods of the important functional units were proposed and compared with those obtained by a medical equipment repair company.Results According to the risk priority number (RPN) score＞ 36,the important functional units of the medical endoscope were determined as electrical interface,water bottle interface,suction interface,housing,chain,pliers pipeline,water gas pipeline,jacket,charge coupled device (CCD) glass,guided beam glass and nozzles.These units require clinical operators to focus on and perform regular maintenances.Compared with the results obtained by the company,human factors were considered as a greater impact on the reliability of medical endoscopes.Conclusions For clinical operators,the operation training of medical endoscopes should be strengthened to avoid human-induced failures.

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