BACKGROUND:Chemokines can promote (MSCs) the secretion of vasoactive factors from mesenchymal stem cel s (MSCs) through paracrine mechanism, which have important role in accelerating angiogenesis. OBJECTIVE:Under the high glucose environment, to the effect of the supernatant of MSCs stimulated by chemokine (C-X-C motif) ligand 8 (CXCL-8) on human umbilical vein endothelial cel s (HUVECs), and to analyze the mechanism of Sonic Hedgehog signaling pathway in the stimulation of CXCL-8 on MSCs. METHODS:Under the high glucose environment, the MSCs supplemented with 100μg/L CXCL-8 were set as CXCL-8 group;the MSCs that were preprocessed with 5μmol/L octyl maleimide for 45 minutes and then stimulated with 100μg/L CXCL-8 were as Shh inhibitor group;the MSCs that were routinely cultured in a high-glucose medium were as control group. The cel supernatant of each group was extracted as conditioned medium (CM) to culture HUVECs, respectively, and these cel s were referred to as CXCL-8 CM group, Shh inhibitor CM group, and control CM group, respectively. Cel counting kit-8, cel scratch and Transwel chamber tests were used to observe the effect of each CM on HUVEC proliferation, apoptosis and chemotaxis. By establishment of a diabetic skin ulcer model in C57BL/6J mice, the CM of each group was used to treat the mouse model to confirm the effects of CXCL-8 stimulated MSCs CM on HUVEC homing and ulcer healing. RESULTS AND CONCLUSION:(1) The experimental results in vitro:compared with the control CM group, CXCL-8 CM group significantly promoted the proliferation of HUVECs, and decreased the apoptosis of HUVECs, the closure rate and migration rate of HUVECs were significantly increased (P<0.01 or P<0.01), and the levels of vascular endothelial growth factor and epidermal growth factor were significantly increased (P<0.01 or P<0.01). Compared with CXCL-8 CM group, however, the above results in the Shh inhibitor CM group showed reverse changes (P<0.01). (2) The experimental results in vivo:compared with the MSCs CM group and Shh inhibitor CM group, the healing effect of diabetic skin ulcer and the number of HUVECs labeled by green fluorescent protein in the CXCL-8 CM group were significantly increased (P<0.01). To conclude, these findings indicate that CXCL-8 stimulated MSCs secrete paracrine factors, vascular endothelial growth factor and epidermal growth factor, through the Sonic Hedgehog signaling pathway under the high glucose environment, which enhance the homing ability of HUVECs.

Objective: To evaluate the clinical efficacy of total arthroscopic anterior talofibular ligament repair for chron-ic lateral instability of ankle joint. Methods: Data of 70 patients with chronic lateral mechanical instability of ankle joint treated by anterior talofibular ligament repair under full scope from September 2016 to October 2017 were retrospectively analyzed. There were 48 males and 22 females, aging from 18 to 49 years old (average, 32.3±3.4 years). Arthroscopic exploration, synovial mem-brane cleaning, extraction of lateral malleolus free body or microfracture were used in the operation, and the anterior talofibular lig-ament was repaired with knottless anchors to restore ankle stability. After the operation, plaster support was used for fixation, and relevant rehabilitation plans were conducted. X-ray films of the front drawer stress position of the ankle joint was taken preopera-tively and during follow-up, and the talus advancing distance was measured preoperatively and during follow-up. Ankle function was evaluated by American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot function score, and pain was evaluat-ed by visual analogue scale (VAS). Results: Seventy patients were followed up for 8-18 months, with an average of 11.5 months. The incisions of all patients were healed in one stage without internal plant rejection reaction. The plaster was fixed for 2 weeks af-ter operation, followed by rehabilitation training 2 weeks later, non-confrontational physical exercise 3 months later and confronta-tional physical exercise 6 months later. Within one year after operation, 58 patients could meet the needs of daily life and exercise. Seven basketball and football fans complained of ankle joint soreness and discomfort after strenuous exercise, and the symptoms were relieved after treatment. The symptoms of foot and ankle instability were not significantly improved in 5 patients. Stress X-ray showed that the talus advancing distance was improved from 11.70±1.05 mm before operation to 3.25±1.09 mm at the latest follow-up, and the difference was statistically significant (t=32.15, P< 0.0001). VAS decreased from 5.70±2.90 before operation to 2.05±0.52 at the latest follow-up (t=11.75, P< 0.0001). AOFAS increased from 54.50±7.40 before operation to 87.80±5.60 at the latest follow-up (t=34.04, P< 0.0001). There was excellent in 53 cases, good in 8 cases, fair in 5 cases, poor in 4 cases, thus the excellent and good rate was 87.14% (61/70). One of the patients suffered from joint pain in ankle metatarsal flexion half a year later, and MRI reexamination found that the anchor had entered the joint cavity, whose symptom was relieved after the anchor was cleared by arthroscopy at the later stage. Conclusion The treatment of lateral chronic instability of ankle joint with arthroscopic non-knot anchor nail repair of anterior talofibular ligament can effectively restore the stability of ankle joint and the movement ability of pa-tients. The operation has advantages of definite curative effect, minimally invasive, fast recovery and easy acceptance by patients.

Objective:To explore the effects of self-made bilingual anatomy micro-lecture on the comprehensive ability training of nursing students, such as autonomous learning, medical English and knowledge expression.Methods:The study group was set up, and the micro-lectures were independently completed by the students under the guidance of teachers. The nursing medical students of Batch 2017 and Batch 2018 were recruited as control group and experimental group, respectively. Micro-lectures were applied in experimental group teaching and students' autonomous learning. The effect of self-made micro-lectures on cultivating students' comprehensive ability was verified by comparing examination results and analyzing questionnaire. SPSS 20.0 was used to conduct t-test. Results:A total of 53 micro-lectures were produced. Compared with the control group, the final theoretical and experimental examination scores of the experimental group were significantly improved ( P < 0.05), and the excellence rate of study group members was 31.25% (10/32); the questionnaire results showed that the satisfaction rate in classroom teaching of using micro-lectures in the experimental group was 90.24%(74/82), and 85.37% (70/82) of the students wanted to participate in the production of micro-lectures; 100.00% (40/40) of the study group members thought that the production of micro-lectures promoted them to perform autonomous learning, more than 82.50%(33/40) of the students indicated that the knowledge expression was effectively trained, and 67.50%(27/40) of the members improved their medical English. Conclusion:The self-made bilingual micro-lectures of anatomy is an effective means to achieve the goal of comprehensive ability training for medical students majoring in nursing.

Objective:To explore the teaching resources innovation and the teaching quality improvement for international students in clinical medicine based on the bilingual test question database of digitalized systematic anatomy.Methods:The test question database was set up and applied to Batch 2018 international students of clinical medicine (experiment group). The results of the usual test, final theory, and experimental examination of Batch 2017 international students (control group) were compared to verify the application value of the test question database. Questionnaires were used to get feedback from international students, and the feasibility of developing the test question database and the driving effect of teaching reform were further evaluated. SPSS 20.0 was used for data analysis, and the examination achievements of the two groups were compared with independent-samples t test and the measurement data were expressed by (mean ± standard deviation). Results:There was no significant difference between the two groups in the usual test results ( P>0.05), and in the experimental group, the results of final theory and experimental examination were significantly higher than those in the control group ( P<0.05). According to the questionnaire, more than 89.55%(155) of the international students highly appraised the test question database in terms of learning resources, quality of questions, examination mode and experience evaluation, while only 52.02%(90) of them recognized the bilingual form of the test questions. Conclusion:The bilingual test question database of digital systematic anatomy has effectively expanded the teaching resources and promoted the teaching reform of international students.

To study the effects and mechanisms of interleukin-8 (IL-8) on the proliferation and autophagy of human bone marrow mesenchymal stem cells (hBMSC) under hypoxic condition. In the hypoxia model, we set the non-stimulated hBMSC as the hypoxia control group; the hBMSC stimulated by 100 μmol/L human IL-8 as the IL-8 group; the hBMSC stimulated by 50 μmol/L MK2206 (Akt protein inhibitor) and 100μmol/L IL-8 as the Akt inhibitor group; and the normal cultured hBMSC as the normal control group. The experiments of EdU cell proliferation and TUNEL apoptosis were respectively used to detect the number of positive cells that were labeled by EdU and apoptosis in each group, and Western blotting and ELISA were used respectively to detect the expression of autophagy protein (LC-3), Akt/STAT3 and other proteins in each group. The results indicated that the proliferation and autophagy of hBMSC in IL-8 group was higher than that in hypoxia control group and Akt inhibitor group, and the apoptosis rate in IL-8 group decreased. These results and the high expression of Akt, STAT3 and VEGF protein of IL-8 group show that under the hypoxic condition, IL-8 played a protective role on MSC through the Akt-STAT3 pathway. It had important significance in the protection of MSC against the injury due to ischemia and hypoxia, and promoted the application of MSC in regenerative medicine.