Free clodronate has a very poor ability to permeate cell membrane and an extremely short half-life in circulation. However, it can be encapsulated with liposomes, and then can be phagocytosed by monocytes/macrophages. Clodronate is released in the cells and be metabolized to a toxic ATP analog. By this way, monocytes/macrophages can be effectively depleted. The study showed that the prepared liposomes had a negative charge (-40mV) on the surface and a high encapsulation efficiency of clodronate (17.6%～19.0%) with an average size of 200nm. The spherical shape of liposome was confirmed both by transmission electron microscope and laser scanning confocal microscope. Neither free clodronate nor liposome clodronate inhibited vascular endothelial cell and smooth muscle cell proliferation. Clodronate, once encapsulated in liposomes, significantly reduced macrophage proliferation in a dose dependent manner, while free clodronate or empty liposomes had no effect on macrophages. With laser scanning confocal microscope observation, rhodamine labeled liposomes were found to penetrate and accumulate inside monocytes and macrophages, but not into the smooth muscle cells. Furthermore, rhodamine labeled liposomes without encapsulating clodronate was found to accumulate inside macrophages, but causing no damage to cells. The macrophages which engulfed rhodamine labeled clodronate liposomes would manifest a morphological structure resembling apoptotic state. The results suggest that monocytes/macrophages can be depleted via phagocytosis of liposome encapsulated clodronate without affecting non-phagocytotic cells.

Objective Island scapular flap (ISF) based on transverse branch of circumflex scapular artery is less reported than ISF based on ascending or descending branch. This article presented authors' experiences in correction of severe axillary burn scar contracture with ISF based transverse branch of circumflex scapular artery. Methods ISFs based transverse branch was harvested in 12 patients with 15 severe axillary burn scar contracture, rotating an arc of about 180°. Flap size was between 12 cm× 5cm to 20 cm × 10 cm. The donor site was closed primarily. Results All 15 flaps survived completely and axillary burn scar contracture was corrected successfully. 8 patients were satisfied with both the functional and aesthetic results after 1-3 years' follow-up. Conclusion ISF based transverse branch of circumflex scapular artery is a good choice for reconstruction of severe axillary burn scar contracture, especially for female patients or ones whose ISF based on ascending or descending branch could not be harvested because of formation of hypertrophic scar in donor site.

Objective To construct recombinant adenovirus vector carrying vascular endothelial growth factor 165(Ad-VEGF165),amplify the adenovirus vector in 293T cells,transfect Ad-VEGF165 into the bone marrow stromal cells(bMSCs) of Wistar rats,and then to assay the expression of VEGF165.Methods VEGF165 obtained by PCR was digested and inserted into adenovirus shuttle plasmid pAdTrack-CMV to generate recombinant plasmid pAdTrack-VEGF165,and then the Pme I-linearized plasmid pAdTrack-VEGF165 was electroporated into E.coli BJ5183 cells that had been electroporated adenovirus backbone plasmid pAdEasy-1.The identified recombinant plasmid pAdEasy-VEGF165 DNA was digested with Pac I and transfected into 293T cells to package adenovirus,followed by identification of the recombinant adenovirus by means of observation of the enhanced green fluorescence protein(EGFP) expression under fluorescent microscope.After amplified in 293T cells,the obtained adenovirus were transfected into 293T cells again,and EGFP expression was detected.Ad-VEGF165 transfected bMSCs were cultured in vitro.The expression of VEGF165 in bMSCs after transfection was determined by observing the expression of EGFP and detected by RT-PCR.ELISA method was applied to assay the secretion of VEGF165.Results Recombinant adenoviral VEGF165 was constructed successfully,which was confirmed by restriction enzyme digestion,gene sequencing and EGFP expression.EGFP expression could be observed under fluorescent microscope,and the expression of VEGF165 was confirmed by RT-PCR.ELISA analysis showed the quantity of expression of VEGF165 in transfection group was higher than that in control group(P

Objective To explore a method of large cranial bone defect reconstructed by titanium implant with computer aided design(CAD)/computer aided manufacture(CAM)technique.Methods From April 2006 to June 2008,7 cases of cranial bone defect due to tumor and trauma were admitted.The data of skull bone defects were obtained by CT.The resin model was designed and manufactured with rapid prototyping technique.Results The CT data could be used by image software directly.The resin model was manufactured accurately by RP technique.The titanium implant design could be completed by CAD/CAM.7 patients achieved one stage healing.After a follow-up of 6 months to 1 year,cranial bone defect was reconstructed satisfactorily.Conclusion Individual design and repair of large cranial bone defect with CAD/CAM technique is worth extending application clinically.It is a quite ideal and very simple method for the surgical treatment of the cranial bone defect.

Objective:To explore the clinical effectiveness of arthroscopic treatment of tibial eminence avulsion fracture by four-point fixation with suture anchors.Methods:A retrospective analysis was performed of the 58 patients with tibial eminence avulsion fracture who had been treated by the same group of surgeons using four-point fixation technique with suture anchors under arthroscopy at Department of Sports Medicine, The Affiliated Hospital to Qingdao University from January 2015 to December 2018. They were 33 males and 25 females, with an average age of 18.4 years (from 14 to 32 years). By the modified Meyers-McKeever classification, 15 fractures were type Ⅱ, 19 type Ⅲ and 24 type Ⅳ. Recorded and compared were knee Lysholm scores, International Knee Documentation Committee (IKDC) scores and tibial eminence height between preoperation and one year postoperation; recorded at the last follow-up were range of knee motion and results of Lachman and pivot-shift tests.Results:The 58 patients were followed up for a mean of 20.7 months (from 12 to 33 months). Bony union was achieved in all patients within 12 weeks after operation. In this cohort, the Lysholm score (85.2±4.9) and IKDC score (86.2±4.3) at one year postoperation were significantly higher than the preoperative values (43.2±5.2 and 51.2±4.9), and the post-operative tibial eminence height [(9.1±1.2) mm] was significantly lower than the preoperative value [(12.6±1.2) mm] (all P<0.05). The correlation coefficients between the tibial eminence height and the Lysholm & IKDC scores at one year postoperation were -0.16 and -0.17, respectively. The last follow-up showed a 132°±5° range of knee motion for all patients, a positive result of pivot-shift test (grade Ⅱ) for 3 and a positive result of Lachman test (grade Ⅰ) for 2. Conclusion:Arthroscopic treatment of tibial eminence avulsion fracture by four-point fixation with suture anchors can lead to satisfactory effectiveness, showing advantages of minimal invasion, anatomic reduction, reliable fixation, and little impact on the epiphysis plate.

Objective:To investigate the effects and mechanism of exosomes secreted by human umbilical cord-derived mesenchymal stem cells （hUC-MSCs） in repair of tendon cell injury.Methods:The hUC-MSCs which were stably subcultured were isolated and purified by a tissue block adherent method，and the immunophenotype of hUC-MSCs was detected by flow cytometry. The induction media was employed to induce the differentiation of hUC-MSCs to osteoblasts，chondroblasts and adipocytes，and cell identification was performed subsequently. The secreted exosomes of MSCs （MSCs-exosomes） were extracted using an ultracentrifugation method. The exosomes were detected by Western blot and electron microscopy，and the fusion ability of the exosome membrane was detected by PKH67 staining fluorescence. Forty Wistar rats were divided into tendon injury group （ n = 20） and normal group （ n = 20） according to the random number table. In tendon injury group，the rats were sacrificed with 100 mg/kg pentobarbital sodium one week after Achilles tendon transection，and the injured tendon cells were obtained following digestion of the Achilles tendon. In normal group，the rats were sacrificed without any treatment and the normal tendon cells were obtained concurrently. After the exosomes were co-cultured with tendon cells in vitro for 12，24，48，72 hours，the proliferation of tendon cells was detected by CCK-8 assay. After the tendon cells were treated with hUC-MSCs exosomes for 24 hours，the effects of exosomes on transforming growth factor β （TGF-β），bone morphogenetic protein （BMP），vascular endothelial growth factor （VEGF），fibroblast growth factor （FGF），interleukin（IL）-1β and tumor necrosis factor-α （TNF-α） were detected by Western blot，qPCR and immunofluorescence. Results:The hUC-MSCs were identified and hUC-MSCs-exosomes were isolated successfully. The cultured MSCs were fusiform and positive for Alanine aminopeptidase （CD13），integrin β-1 （CD29），ECTO-5'-nucleotidase （CD73），thymocyte surface antigen （CD90） and endothelin （CD105），but negative for human leukocyte DR antigen （HLA-DR），hematopoietic progenitor cell antigen （CD34） and leukocyte common antigen （CD45）. The exosomes isolated showed a round disc shape and a diameter of 30-100 nm with a depressed internal structure under the electron microscope which was verified via PKH67 staining and the motility-related protein-1 （CD9） and lysosomal associated membrane protein 3 （CD63） were highly expressed. The CCK-8 assay showed the cell viability in tendon injury group was markedly higher than that in normal group at 12 h，24 h，48 h，and 72 h following treatment of tendon cells （ P < 0.01）. The results of qPCR revealed that the mRNA expressions of TGF-β （1.850 ± 0.127），BMP （2.133 ± 0.398），FGF （1.610 ± 0.223） and VEGF （2.207 ± 0.059） in tendon injury group were markedly higher than those in normal group（1.004 ± 0.105，1.007 ± 0.145，1.007 ± 0.140，1.001 ± 0.065，respectively） （ P < 0.05）. However，the mRNA expressions of IL-1β （0.102 ± 0.009） and TNF-α （0.130 ± 0.013） in tendon injury group was markedly lower than those in normal group （1.004 ± 0.113，1.006 ± 0.134） （ P < 0.01）. The results of Western blot were consistent with those of qPCR. Conclusions:The exosomes secreted by hUC-MSCs can promote the growth of tendon cells and repair of tendon cell injury by up-regulating the expression of growth factors TGF-β，BMP，VEGF and FGF，and inhibiting the expression of inflammatory factors IL-1β and TNF-α.

Objective:To study the effect of microglia depletion combined with bone marrow mesenchymal stem cells (BMSC) transplantation for spinal cord injury (SCI) repair.Methods:GFP-BMSCs were cultured, identified and detected for expression levels of growth factors. The effects of BMSCs ondorsal root ganglion (DRG) axon outgrowth were observed by the co-culture of BMSCs with DRGs. Mice were depleted of microglia by administrating the colony stimulating factor 1 receptor (CSF1R) inhibitor PLX3397. The spinal cords of these microglia-depleted mice were subjected to crush injury. BMSCs were transplanted into SCI area after microglia depletion. Mice were randomly divided into control group (SCI+BMSCs) and experimental group (PLX3397+SCI+BMSCs). Mice were sacrificed at corresponding time points after transplantation for observing the survival of transplanted BMSCs and the repair of spinal cord. BMS score was used for evaluation of motor function recovery.Results:BMSCs secreted a large number of neurotrophic factors and promoted the growth of DRG axons when co-cultured with DRGs. Depletion of microglia significantly improved the survival of transplanted BMSCs. Compared with BMSCs transplantation alone, the combined treatments slightly but non-significantly reduced the area of the lesion ( t=2.141, P=0.065). Immunofluorescence staining showed that both BMSC transplantation alone and the combined treatments did not cause the corticospinalaxons across the lesion and into distal spinal cord. BMS scores were (1.20±0.45), (3.20±0.45), (3.80±0.45), (4.20±0.45), and (4.60±0.55) points in control group at 1, 7, 14, 21 and 28 d after injury. The experimental groups were(0.60±0.55), (3.00±0.71), (3.80±0.84), (4.20±0.84), and (4.40±0.89) points, respectively. Conclusion:Depletion of microglia improves the survival of transplanted cells, depletion of microglia combined with BMSC transplantation did not result in a significant reduction in lesion area. At the same time, the damaged CST axons were notregenerated. Thus, combining cell transplantation with axon-promoting strategy may be necessary for SCI repair.

Objective:To investigate the significant effects of enhanced whole-body computed tomography (EWBCT) and non-enhanced whole-body computed tomography (N-EWBCT) on the missed diagnosis rate, renal function and prognosis of patients with severe trauma.Methods:Clinical data of trauma patients admitted from January 1, 2017 to December 31, 2020 were collected from the trauma database of the Trauma Center of the Second Affiliated Hospital of Soochow University. All patients included in this study were divided into the EWBCT group and N-EWBCT group according to whether they underwent enhanced whole-body computed tomography examination. The differences in baseline data, missed diagnosis rate, renal function and prognosis of the two groups of patients were compared.Results:A total of 459 patients were included in this study, including 184 patients in the EWBCT group and 275 patients in the N-EWBCT group. The missed diagnosis rate of the N-EWBCT group was significantly higher than that of the EWBCT group (18% vs. 5%, P < 0.01). The risk ratio of acute kidney injury (AKI) in the EWBCT group and N-EWBCT group was 9% and 7%, respectively, and there was no statistical difference between the two groups ( P >0.05). The mortality rate of patients in the N-EWBCT group was higher than that in the EWBCT group (23% vs. 12%, P=0.002). Conclusions:Compared with N-EWBCT, EWBCT does not significantly increase the risk of renal damage in patients with severe trauma. For patients with severe trauma, early EWBCT can reduce the missed diagnosis rate and improve the clinical prognosis.

Objective:To compare the clinical efficacy between the pressing tendon suture with a lateral anchor and the knotted suture with a lateral anchor in the treatment of severe rotator cuff tear under shoulder arthroscopy.Methods:A retrospective study was conducted of the 42 patients who had been treated at Department of Orthopedic Sports Medicine, Affiliated Hospital to Qingdao University from December 2018 to December 2019 for severe rotator cuff tear. They were 13 males and 29 females, with an age of (58.3±10.1) years (from 32 to 74 years). The injury was on the right side in 26 cases and on the left side in 16 cases. Of them, 22 received pressing tendon suture with a lateral anchor under shoulder arthroscopy and 20 knotted suture with a lateral anchor under shoulder arthroscopy. The flexion, abduction and external rotation of the shoulder, Visual Analog Scale (VAS) pain score, University of California-Los Angeles (UCLA) score, Constant-Murley shoulder score, American Shoulder and Elbow Surgeons (ASES) score and imaging MRI Sugaya grading were compared between the 2 groups 12 months after operation.Results:There was no significant difference in the preoperative general data between the 2 groups, showing comparability between them ( P>0.05). At 12 months after operation, the pressing tendon suture group had better abduction and flexion of the shoulder, a lower VAS pain score and a higher ASES score than the knotted suture group, but the differences were insignificant ( P>0.05). At 12 months after operation, the pressing tendon suture group achieved significantly better external rotation (39.2°±11.7°) and significantly higher UCLA score (28.1±4.7) and Constant-Murley shoulder score (77.0±9.3) than the knotted suture group (29.8°±14.6°, 22.1±5.7 and 66.4±11.0) ( P<0.05). At 12 months after operation, the imaging MRI Sugaya grading was significantly lower for the pressing tendon suture group than that for the knotted suture group ( P<0.05). Conclusion:In the treatment of patients with severe rotator cuff tear under shoulder arthroscopy, the pressing tendon suture with a lateral anchor may lead to better clinical prognosis than the knotted suture with a lateral anchor.