Lentivirus-mediated microRNA-124 gene-modified bone marrow mesenchymal stem cell transplantation promotes the repair of spinal cord injury in rats

Our study aims to explore the effects of lentivirus-mediated microRNA-124 (miR-124) gene-modified bone marrow mesenchymal stem cell (BMSC) transplantation on the repair of spinal cord injury (SCI) in rats. BMSCs were isolated from the bone marrow of rats. The target gene miR-124 was identified using a luciferase-reporter gene assay. Seventy-two rats were selected for construction of the SCI model, and the rats were randomly divided into the blank group, sham group, SCI group, negative control (NC) group, overexpressed miR-124 group and si-PDXK group. The mRNA expression of miR-124 and the mRNA and protein expression of pyridoxal kinase (PDXK) were detected by quantitative real-time polymerase chain reaction and western blotting. The locomotor capacity of the rats was evaluated using the Basso, Beattie and Bresnahan (BBB) scale. Brdu, neuron-specific enolase (NSE), neurofilament (NF) and microtubule-associated protein 2 (MAP2) were detected using immunohistochemistry. The expression levels of thyrotropin-releasing hormone (TRH), prostacyclin (PGI2) and gangliosides (GM) were measured using an enzyme-linked immunosorbent assay. PDXK was identified as the target gene of miR-124. The overexpressed miR-124 group exhibited higher miR-124 expression than the SCI, NC and si-PDXK groups. Compared with the SCI and NC groups, the PDXK expression was downregulated in the overexpressed miR-124 and si-PDXK groups, and the BBB scores were significantly increased 7, 21 and 35 days after transplantation. The double-labeled positive cell densities (Brdu+NSE/NF/MAP2) and the expression levels of TRH, PGI2 and GM in the overexpressed miR-124 group were significantly higher than those in the NC and SCI groups. These results indicated that miR-124 targeted PDXK to accelerate the differentiation of BMSCs into neurocytes and promote SCI repair.

Free peroneal perforator-based sural neurofasciocutaneous flaps for reconstruction of hand and forearm / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Sural neurofasciocutaneous flap has been popularly used as an excellent option for the coverage of soft tissue defects in the lower third of leg, ankle and foot, but its free transplantation has been rarely reported. The objective of our work was to investigate the operative technique and clinical results of repairing the soft tissue defects of hand and forearm with free peroneal perforator-based sural neurofasciocutaneous flap.</p><p><b>METHODS</b>Between May 2006 and March 2007, 10 patients including 7 men and 3 women were treated. Their ages ranged from 22 to 51 years. They presented to emergency with large soft tissue defects of 16 cm x 7 cm to 24 cm x 10 cm in size in hand and forearm after injured by motor vehicle accidents (2 cases) or crushed by machine (8 cases). Thorough debridements and primary treatments to associated tendon ruptures or bone fractures were performed on emergency. And free peroneal perforator-based sural neurofasciocutaneous flaps were transplanted when the wound areas were stable at 5 to 7 days after emergency treatment. The flaps were designed along the axis of the sural nerve according to the shape and size of the soft tissue defects, with the peroneal perforator above the lateral malleolus as the pedicle and along with a part of the peroneal artery for vascular anastomosis. Then the flaps were harvested to repair the recipient sites with the peroneal artery anastomosed to the radial (or ulnar) artery and the peroneal veins to one of the radial (or ulnar) veins and the cephalic vein respectively. The flap sizes ranged from 18 cm x 8 cm to 25 cm x 12 cm. The donor areas were closed by skin grafts.</p><p><b>RESULTS</b>All of the 10 flaps survived after surgeries. Marginal necrosis occurred in only 2 cases. The skin grafts survived entirely in the donor sites, and no obvious influence on the donor legs was observed. All of the transplanted flaps presented favourable contours and good functions at 9 to 12 months' follow-up.</p><p><b>CONCLUSIONS</b>Peroneal perforator-based sural neurofasciocutaneous flap has favourable appearance, constant vascular pedicle, reliable blood supply, large size of elevation, and minimal influence on the donor site. The free transplantation of this flap offers a satisfactory alternative for repairing the large soft tissue defects of forearm and hand.</p>

Effect of tension on force of contraction of muscle and nerve conduction velocity of the repaired nerve in a rat model.

To investigate the effect of tension on the contractive force of muscle and nerve conduction velocity of the repaired nerve, this study was designed. Fifty-four Sprague-Dawley (SD) rats were randomly divided into 3 groups. The left gastrocnemius muscles of the rats were dissected with the neurovascular pedicles intact; the tibial nerves were cut and immediately repaired by epineurial suture. Then the Achilles tendons were isolated and treated accordingly; the Achilles tendon was lengthened by 0.5 cm in lengthened group, shortened by 0.5 cm in shortened group and left alone in normal (control) group. In the 2nd, 4th and 8th weeks after operation, the isometric twitch contractive force of both the right and the left gastrocnemius muscles and the nerve conduction velocity (NCV) of the tibial nerve were measured. The shortened group showed greater isometric twitch contractive strength of the bilateral gastrocnemius muscles than those in the normal and lengthened groups in all the postoperative periods. The nerve conduction velocity (NCV) in the shortened group showed greater than other groups. A proper high tension of the muscle can increase the contraction of the muscle and may improve the nerve conduction velocity of the repaired nerve.

Arthroscopically assisted treatment of tibial plateau fractures by tractive reduction with external fixator / 中华外科杂志

<p><b>OBJECTIVE</b>To study the clinical effect of tractive reduction with external fixator and arthroscopically assisted treatment for tibial plateau fractures.</p><p><b>METHODS</b>From February 2003 to January 2005, a total of 26 cases with tibial plateau fractures were reviewed. There were 4 cases of type I fracture, 5 type II, 4 type III, 6 type IV, 5 type V and 2 type VI based on Schatzker criteria. Before operation, X-ray examination and CT scanning were done. During operation, the dissociative fragments were reconstructed by tractive reduction with external fixator arthroscopically and fixated with screws or plates.</p><p><b>RESULTS</b>All the fractures were healed within 1.5 - 4 months, with no severe complications such as poor wound healing, infection or osteofascial compartment syndrome. All patients that were followed up for 7 - 21 months (mean, 16 months) showed no traumatic osteoarthritis, inversion or eversion of the knee. According to the Rasmussen scoring system, the outcome was excellent in 11 cases, good in 13 and fair in 2, with total score of 27 +/- 2.</p><p><b>CONCLUSIONS</b>As for Schatzker type I - VI tibial plateau fractures, tractive reduction with external fixator and arthroscopically assisted treatment is characterized by minimal invasion, fast fracture healing. It broadens operative interspace of articular cavity, improves accuracy of reduction, is beneficial for knee joint function to recover.</p>

Experimental Study of the Bionic Technology for the Construction of Small-caliber Vascular Prostheses / 中国生物工程杂志

Objective:To study the feasibility of using the bionic technology to construct small-caliber vascular prostheses with modified SIS.Methods: The vascular endothelial cells and smooth muscle cells were separated from canine saphenous artery,the cells blended with collagen gel,which were planted respectively on the SIS films,these films were rolled into the biologic three-layer prostheses around a 3mm diameter polyethylene tube;one-layer prostheses without these cells and collagen gel served as control.These 2 types of prostheses were implanted into the defect of bilateral canine femoral by anastomosis in 15 dogs.doppler colour ultrasonic,histology detection and electron microscope examination were done postoperatively.Results: By 12 weeks postoperatively,14 biologic vascular prostheses had kept well patency,the patency rate being 93.3%,the biologic structure like blood vessels had formed,the inner surface of the vessels had been covered with full endothelial cells,a lot of smooth muscle cells had been found in the media of vascular walls in regular line;the patency rate in control group was 60.0%,the endothelial cell coverage was incomplete.Conclusions: The bionic vascular prostheses showed potent blood compatibility,which could keep long-term patency in vivo.Curative effect of repairing the small-caliber vessel defect was well satisfactory.

Application of vascularized free tissue transplantation in emergency repair of traumatized limbs:report of 86 cases / 中华显微外科杂志

Objective To report the outcome of emergency repair traumatized limbs by vascularized free tissue transplantation.Methods From April 1988 to August 2004,86 patients,58 men and 28 women,had undergone emergency vascularized free tissue transplantation to have their injured limbs repaired in 54 cases and the missing thumbs reconstructed in 32.The patients aged from 5 to 55 (mean 27.9) years. The transplants included latissimus dorsi myocutaneons flap,anterolateral femoral skin flap,medial crural skin flaps,dorsal pedal flaps,medial plantar flap,composite tissue mass of the discarded limbs and big toe skin- nail flap.The operations were performed 1 to 5 days after injuries.Results Postoperative vascular crises occurred in 8 cases and were all followed by exploration with successes in 5 cases while failure in 3.The total survival rate of the transplants was 96.5% (83/86).In this series all the patients were followed up for 1 to 16 years with a mean of 7.5 years only to reveal satisfying functional recovery in all the repaired limbs and an ex- cellent and good rate of 87.5% in the reconstructed thumbs.Conclusion Emergency vascularized free tis- sue transplantation is an effective way to repair a traumatized limb and to reconstruct a traumatically missing thumb.

Study on antithrombogenicity and surface heparinization of small intestinal submucosa / 中华创伤骨科杂志

Objective To study surface heparinization of small intestinal submucosa(SIS)and an- tithrombegenicity of beparinized SIS films with plasma initiation technique for the engineering vascular scaffolds. Methods The SIS films were grafted with heparin by hypothermia plasma initiation technique.The blood com- patibility of the modified SIS films was assessed by observing blood coagulation time in vitro and the long term pa- tency of hepafinized SIS vascular scaffolds directly under the circulation of blood.Results The hypothermia plasma initiation method could attach heparin onto the SIS surface,The water contact angle of SIS films modified with heparin was decreased while the surface free energy and hydrophilicity increased.The prothrombin time(PT),ac- tivated partial thromboplastin time(APTT)and thrombin clotting Time(TT)of the SIS films modified with heparin were prolonged obviously.Small caliber engineering vascular scaffold made of heparinized SIS films kept the patency for six weeks.Conclusion Heparin can be attached to SIS films by hypothermia plasma initiation technique.The modified surfaces provide good and persistent antithrombogenicity,and possess potent blood compatibility,

Intracapsular reduction for comminuted distal radial fractures / 中华创伤杂志

Objective To explore the application and clinical outcome of intracapsular reduction for comminuted distal radial fractures.Methods From January 2003 to October 2005,37 cases of comminuted fractures of distal radius were treated in our hospital.They were categorized according to the AO classification,and underwent open intracapsular reduction,internal fixation with either locking com- pressing plate(LCP)or external fixator according to the types of fractures.The results of treatment were evaluated by functions and X-ray examination of involved wrists.Results All the 37 patients were fol- lowed up regularly.Satisfied synostosis by X-ray had been acquired.The wrist functions were evaluated by the Gartland and Werley system to find excellent result in 26 cases,good in eight,fair in two,and poor in one,with the excellent and good rate of 92%.Conclusion For the treatment of comminuted distal radial fractures,open intracapsular reduction can obtain fast fracture healing and recovery of wrist joint function.