Objective To investigate the influence of external electric fields on migration behavior and morphology of endo‐thelial progenitor cells (EPCs) cultured in vitro .Methods The in vitro cultured 3-4 generation EPCs were continuously stimula‐ted by direct‐current electric field with the field intensity of 0 mV/mm(group Ⅰ ) ,100 mV/mm(group Ⅱ) ,200 mV/mm(group Ⅲ) and 300 mV/mm (group Ⅳ )for 3 h .The live cell station was used to real time record the cell migration track and morphology change of EPCs .The influence of external electric field on the EPCs migration behavior and morphology was analyzed .Results Un‐der the stimulation of the direct‐current electric field with the intensity of group Ⅳ ,group Ⅲ and group Ⅱ ,the cells were directly migrated to anode ,while the cells under group Ⅰ displayed the random motion .The track migration velocity(Vt)、displacemnt ve‐locity(Vd) and electric field direction migration rate(Vx) were(98 .86 ± 6 .00) ,(63 .78 ± 2 .81) ,(63 .15 ± 2 .88)μm/h for the groupⅣ ,(88 .06 ± 8 .83) ,(35 .90 ± 1 .22) ,(34 .20 ± 1 .57)μm/h for the groupⅢ ,(42 .28 ± 2 .25) ,(13 .29 ± 0 .37) ,(12 .39 ± 0 .51)μm/h for the groupⅡ ,which were significantly higher than(37 .39 ± 2 .42) ,(6 .99 ± 0 .31) ,(4 .62 ± 0 .40)μm/h for the groupⅠ (P<0 .01) ,moreover Vt ,Vd and Vx in the group Ⅲ were significantly higher than those in the group Ⅱ andⅠ (P<0 .01) .EPCs had obvious morphological changes under the electric field action ,such as elongation and the cellular long axis parallel to the electric field direction .Conclusion External direct current electric fields may induce the directed migration of EPCs towards the anode ,ac‐celerates the migration rate ,moreover has obvious influence on EPCs morphology .

Objective To review the relevant causes for and treatment of nerve injuries in the anterior cervical surgery. Methods From January 2008 to December 2009,859 cages of cervical spondylosis,ossification of cervical posterior longitudinal ligament and cervical spine trauma were treated by anterior cervical surgery.This study retrospectively analyzed the clinical data of seven cases who were with worsened symptoms of spinal cord injury and related nerve injury. Results Of 859 cases,five cases(0.58%)were with spinal cord injury,one(0.12%)with recurrent laryngeal nerve injury and one (0.12%)with laryngeal nerve injury.Hematoma occurred in four cases after surgery caused spinal cord injury and all the four patients recovered to normal after removal of the hematoma and timely treatment with mythylprednisolone and hyperbaric oxygen.Cervical spine trauma was worsened in one patient after the anterior cervical surgery.The patient restored to its original level of spinal cord gradually through some measures such as tracheotomy,ventilator support,hormone therapy and hyperbaric oxygen treatment.Laryngeal nerve injuries in two cases recovered to normal after conservative treatment with hormone,dehydration and other drugs within three months after surgery. Conclusions Anterior cervical surgery of cervical spondylosis,ossification of cervical posterior longitudinal ligament and cervical spine trauma are likely to induce the related nerve damage.The good prognosis can be obtained under timely prevention and treatment.

BACKGROUND:The therapeutic effectiveness on tendon injury is closely related to the material of tendon suture.
OBJECTIVE: To review the progress of tendon suture materials and tendon biomechnics in recent years.
METHODS:A computer-based search of CNKI (January 1999 to December 2014), and PubMed (January 1950 to December 2014) was performed for relevant articles using the keywords of “tendon, suture materials,
biomechanics” in Chinese and English, respectively.
RESULTS AND CONCLUSION:Ideal tendon repair refers to the restoration of the continuity of its anatomical structure, tensile strength and sliding function in physiology, which is influenced by many factors. Suture technique and choice of suture materials are two steps that cannot be ignored. With the development of surgical tendon suture technique, in order to improve the quality of tendon healing, ideal tendon suture is first to have sufficient strength to avoid an early tensile fracture; secondly, the elasticity cannot be too large that can cause a gap between suturing ends and affect tendon healing, and time for protecting the tendon strength is as long as possible. Therefore, the optimal choice of tendon suture materials should be based on suture methods and biomechanical characteristics of suture lines, thereby to promote tendon healing.

Objective: To report the effects of operative treatment of Sneppen Ⅴ talus fracture through the approach for malleolus medialis Ⅴ osteotomy plus hollow compression screw fixation. Methods: From January 2015 to January 2019, 16 patients with Sneppen Ⅴ talus fracture were treated at Department Ⅱ of Hand & Foot Microsurgery, The Second Affiliated Hospital to Inner Mongolia Medical University. They were 14 men and 2 women with a mean age of 38.4 years (range, from 20 to 55 years). All fractures were fixed with hollow compression screws through the approach for malleolus medialis Ⅴ osteotomy. The ankle and hindfoot functional scoring system developed by American Orthopaedic Foot and Ankle Society (AOFAS) was used to evaluate the clinical outcomes. Results: All patients were followed up for a mean time of 12.6 months (range, from 6 to 30 months). The mean operation time was 68.4 minutes (range, from 52 to 96 minutes); the mean amount of hemorrhage during operation was 96.8 mL (range, from 48 to 122 mL); the mean period of bone union was 4.8 months (range, from 3 to 8 months). The postoperative mean AOFAS score was 75.3 points (range, from 43 to 91 points). Complications occurred in 4 cases, including one case of talus ischemic necrosis, one case of partial talus ischemic necrosis accompanied by tibial arthritis, one case of subtalar arthritis, and one case of combined tibial, talar and subtalar arthritis. All incisions obtained primary healing, with no complications like infection, screw breakage, delayed union or nonunion. Conclusion Operative treatment of Sneppen Ⅴ talus fracture through the approach for malleolus medialis Ⅴ osteotomy plus hollow compression screw fixation can provide sufficient operative exposure to facilitate reduction and fixation of the talus fracture so that the ischemic necrosis of the talus and traumatic arthritis can be effectively reduced.

Objective To investigate the clinical effect of anterior controllable antedisplacement and fusion (ACAF) for the treatment of ossification of the posterior longitudinal ligament (OPLL) of the cervical spine.Methods The data of 45 cases with cervical posterior longitudinal ligament ossification treated by ACAF from March 2017 to October 2017 were retrospectively analyzed,including 25 males and 20 females,age 45-68 years,average 57.5 years.There were 18 cases involving C3 vertebral body,30 cases involving C4 vertebral body,40 cases involving C5 vertebral body,34 cases involving C6 vertebral body,and 7 cases involving C7 vertebral body.The function of the neural function was evaluated by the Japanese Orthopaedic Association (JOA) scoring system at preoperation and latest follow-up.The curvature of the cervical spine was measured on the lateral X-ray film of the cervical spine,the maximum occupying ratio of the spinal canal was measured on the cross section of the CT scan,and compression of the cervical spinal cord was evaluated by the cervical MRI.Results Patients were followed up for 3 to 6 months (average,3.9 months).The improvement of neurological function was obtained in all the patients.The JOA score improvement rate at the latest follow-up was 71.3％±9.6％.The cervical lordosis was improved from preoperative 4.5°±3.8° to 10.3°±4.8° at the latest follow-up.The canal stenosis ratio was decreased from preoperative 54.3％±8.2％ to 12.5％±5.3％ at the latest follow-up.MRI showed that the cervical spinal cord was adequately decompressed in situ.No specific complications were identified that were associated with this technique.Conclusion The present study elaborates the surgical tips and demonstrates the satisfactory outcome of ACAF for the treatment of OPLL.This novel technique has the potential to serve as an alternative surgical technique for the treatment of cervical OPLL.

OBJECTIVE: To evaluate the changes of cardiac structure and function and their risk factors in elderly patients with obstructive sleep apnea syndrome (OSA) without cardiovascular complications. METHODS: Eighty-two elderly OSA patients without cardiovascular disease admitted between January, 2015 and October, 2016 were enrolled in this study. According to their apnea-hypopnea index (AHI, calculated as the average number of episodes of apnoea and hypopnoea per hour of sleep), the patients were divided into mild OSA group (AHI < 15) and moderate to severe OSA group (AHI ≥ 15). The demographic data and the general clinical data were recorded and fasting blood samples were collected from the patients on the next morning following polysomnographic monitoring for blood cell analysis and biochemical examination. Echocardiography was performed within one week after overnight polysomnography, and the cardiac structure, cardiac function and biochemical indexes were compared between the two groups. RESULTS: Compared with those with mild OSA group, the patients with moderate to severe OSA had significantly higher hematocrit (0.22±0.08 CONCLUSIONS Cardiac diastolic function impairment may occur in elderly patients with moderate or severe OSA who do not have hypertension or other cardiovascular diseases, and the severity of the impairment is positively correlated with AHI.
Aged ; Cardiovascular Diseases/etiology* ; Humans ; Risk Factors ; Severity of Illness Index ; Sleep Apnea, Obstructive/complications* ; Stroke Volume ; Ventricular Dysfunction, Left ; Ventricular Function, Left