It is a clinically tough problem to repair compound tissue d efects of limbs. Application of microsurgical technique with autologous pedicel or free tissue grafts has saved numerous invalid limbs with tissue defects, and is still an essential method to restore compound tissue defects of limbs and res love effectively many difficult problems, such as larger solf tissue defects,seg mental bone defects, bone-skin compound defect, and etc. Microsurgical repair i n emergency has special value in treating compound tissue defects of hand. Altho ugh the resource of autologous tissue graft as donator is limited, tissue engine ering and gene technology hold the promise of revolutionary advances in repairin g compound tissue defects of limbs. Because of the achievements made in the fiel ds of trauma repair and tissue regeneration, both structure and function will be hopefully restored.

Objective To investigate the influence of low frequency micromovement induced by an external fixator with controlled micromovement device on callus formation and fracture healing. Methods 39 sheep were involved in the study. After transverse osteotomy with a gap of 2 mm was done at the mid-shaft of both tibias, the hind limbs were fixed with unilateral external fixators with controlled micromovement device. 10 days after osteotomy, one hind limb of the sheep was randomly selected to have micromovement. According to different micromovement frequencies, the sheep were randomly divided into 3 groups: Group A, 0.5 Hertz; Group B, 1 Hertz; Group C, 5 Hertz. The micromovement had an amplitude of 0.25mm and stopped by the end of the fourth postoperative week (30 min/d). The other hind limb of each sheep did not have micromovement and served as the control. Macrostructural and histological observations, radiographic examinations, and biomechanical tests were done respectively at 4, 6, 9 weeks after osteotomy. Results Macrostructural observations and X-ray examinations revealed a large amount of callus formation with a peak at the end of the fourth postoperative week in the 3 experimental groups. Histological analysis showed faster endochondral ossification and osteoid formation in the experimental groups than in the control by the sixth postoperative week, with the highest rate in Group B (1Hz). Biomechanical tests proved that the bending stiffness in the experimental groups was superior to that in the control, with the strongest in Group B (1 Hz). Conclusions Low frequency-micromovement at the fracture sites can promote callus formation and accelerate mineralization at the early stage of fracture healing. A frequency of 1 Hz can produce the best results.

Objective To observe and analyze the outcomes o f open reduction and Y plate internal fixation in treatment of intra-articular calcaneal fractures.Methods Open reduction and Y plate internal f ix-ation by the extended L-shaped lateral approach were performed in 68pati ents with 82cases of intra-articula r calcaneal fractures under X-ray.Results82cases were followed up for an avera ge of 26months,and the clinical results were evaluated wit h the Maryland Foot Score.58cases ac hieved excellent results,16good,6fair,with the rate of excellent and good re sults being 90.24%.Conclusion Open reduction and Y plate internal fixation can obtain good clinical re sults in treatment of intra-articul ar calcaneal fractures.[

Objective To report the technique and outcome of combined transplantation of bilateral vascularized fibulas to repair the segmental femoral defect Method In the period from October 1984 to May 1992, bilateral vascularized fibula transfer was done to treat femoral defects in 9 cases, in which there were 5 cases of bone tumor, 3 cases of pathological fractures following chronic osteomyelitis and 1 case of posttraumatic bone defect The length of the transferred fibulas ranged from 12 cm to 22 cm and averaged 16.25 cm Result Except 1 case in which thigh amputation was done 6 months after operation because of local recurrence of the chondrosarcoma, all the transferred fibulas united solidly with the host bones 3-6 months after operation The repaired limbs started weight-bearing at the third to seventh postoperative month Conclusion To repair a femoral defect over 10 cm in length, combined transfer of bilateral vascularized fibulas is the treatment of choice with short therapeutic process and good results.

Objective To evalute the effect of Ilizarov technique in the treatment of hypertrophic nonunion.Methods Form June 2008 to December 2010,12 patients with hypertrophic nonunion were treated with Ilizarov technique,including 10 males and 2 females with an average age of 46.5 years.The pathology sites of nonunion were kept as closed as possible without any bone graft during operation.As to patients who had ever been treated with plate or intramedullary nail,the hardware should be removed by minimal invasive approach.These procedures aimed to keep the vascularity of nonunion site intact.Ilizarov apparatus were preoperatively constructed.Distal segment and proximal segment of nonunion were mounted respectively with two external circle using the smooth wires and half pins.The two-circle stabilizing one segment was nominated with transosseous modules.Distal module and proximal one was connected with a pair of axial hinges.The pathology sites were gradually distracted from the seventh day postoperatively,0.25 mm/d.Accompanying with deformity correction,limb length discrepancy (LLD) also were restored simultaneously.Then,all the screws and nuts in the apparatus should be tightened,which was favourable to the callus consolidation.Results All 12 cases of nonunion healed without any bone graft.The fixator wearing time lasted 6-12 months,with an average of 8 months.Correction of deformity and LLD were achieved.The average lengthening was 3.0 cm (range,2.0-5.5 cm),the average correction angle was 23° (range,10°-30°).After 6-18 months follow-up,all the patients restored satisfactory function.Conclusion Hypertrophic nonunion can be treated successfully with Ilizarov technique.The key of successful callus distraction is strictly identifying the indications.

Resistance to breast cancer (BCa) chemotherapy severely hampers the patient's prognosis. MicroRNAs provide a potential therapeutic prospect for BCa. In this study, the reversal function of microRNA34a (miR34a) on doxorubicin (Dox) resistance of BCa and the possible mechanism was investigated. We found that the relative level of miR34a was significantly decreased in Dox-resistant breast cancer cell MCF-7 (MCF-7/A) compared with Dox-sensitive MCF-7 cells. Transfection with miR34a significantly suppressed the invasion, migration, adhesion of MCF-7/A cells without inhibiting their growth obviously. The combination of miR34a and Dox could significantly inhibit the proliferation, migration, invasion and induce the apoptosis of MCF-7/A cells. The synergistic effect of this combination on resistant MCF-7/A cells has no obvious relation with the expressions of classical drug-resistant proteins P-GP, MRP and GST-