AIM: To study the endothelial progenitor cell markers and biological characteristics of human umbilical cord blood CD133+ cells isolated by immunomagnetic bead (IMB) method. METHODS: The experiment was carried out in the Laboratory of Burn Surgery, Xijing Hospital of the Fourth Military Medical University of Chinese PLA from November 2002 to August 2003.①CD133+ cells were enriched from human umbilical cord blood of placenta through spontaneous delivery or cesarean delivery (offered by Department of Gynecology and Obstetrics, Xijing Hospital of the Fourth Military Medical University of Chinese PLA), with the informed consents of parturients.②Human umbilical cord blood was anticoagulated by ACD-B and then diluted, 7 mL of cord blood combined with 3 mL lymphocyte isolation liquid were centrifuged for 30 minutes at 2 100 r/min. Low-density mononuclear cells coloring buffy were selected to wash off platelet and inoculated for 30 minutes by the IMB and FITC-CD133 antigen at room temperature to wash excessive antigens. The FITC-CD 133-coated IMB was added into mononuclear cells which were cultured for 30 minutes at room temperature and placed in magnetic field for 1 minute to remove the cell suspension. IMB-cell isolation liquid was supplemented to release CD133+ endothelial progenitor cells, which were cultured with EGM-2MV media in dishes coated with collagen I. And 24 hours later those unadherent cells were detached, culture liquid was removed half after 3 hours, and total culture duration was 3-4 weeks.③The morphologic change of CD133+ cells isolated with IMB were observed; The percentage of CD133+ cells in cord blood monocytes and sorting efficiency of IMB were analyzed by fluorescence activated cell sorting (FACS). The cells cultured in vitro were identified by fluorescence immunoassay and enzymo-histochemistry while transmission electron microscope (TEM) was used to observe the W-P body of mature vascular endothelial cells. RESULTS: ①Morphologic observation of CD133+ cells culture in vitro: The adherent cells expanded pseudopods on days 4 and 5, and grew rapidly in clonal manner 7 days later. The cells showed a typical spindle-shaped morphology during 2-3 weeks and cluster areas of cobblestone-like cells after 2-week culture and confluence.②Isolation rate of CD133+ cells: The percentage of CD133+ cells in cord blood monocytes was 0.91%. And after IMB sorting, the percentage of CD133+ cells was 85.52%.③On the fifth day, few cells were positive for CD133 while most cells were positive for CD 34 and vWF; On the tenth day, all cells were negative for CD133 and most cells were still positive for CD 34 and vWF.④The cells after 10-day culture had typical W-P body in TEM. CONCLUSION: Immunomagnetic sorting can efficiently select enriched CD133+ endothelial progenitor cells from human umbilical cord blood. Our data of CD133, CD34, vWF antibodies and TEM support the hypothesis that endothelial progenitor cells may contribute to mature vascular endothelial cells.

Objective To investigate the difference of vacuum sealing drainage (VSD) on the effect of one-stage skin graft and second-stage sugery after scar release.Methods A total of 42 patients who wanted to undergo scar release and skin graft was randomly divided to control group (n =21) and VSD treatment group (n =21).The control group implemented skin graft immdiately after scar release while VSD treatment group were treated with VSD for 3 days after scar release and then implemented skin graft.The rate of subcutaneous blood stasis and the survival rate of skin graft were observed at 7 days after skin graft.The condition of grafted skin contracture and hyperplasia after half a year was also observed.Results The incidcnce of subcutaneous blood stasis was significantly lower in the VSD group than that in the control group (P ＜ 0.05).The survival rate of skin grafts was significantly higher in the VSD group than that of the control group (P ＜ 0.05).The score of Vancouver scar was significantly lower in the VSD group than that in the control group (P ＜ 0.05).Conclusions VSD treatment of second-stage sugery after scar release can reduce the occurrence of subcutaneous blood stasis,promotc skin graft survival,reduce postoperative skin graft contracture and improve the prognosis of patients compared to one-stage skin graft.

Objective To explore the method of pre expanded deltopectoral flap for repairing post burn faciocervical scars.Methods Anterior axillary incisions were made and appropriate expanders were implanted above anterior chest wall at the first stage.After a 4 6 months' expanding,the flaps based on perforating branches of the internal mammary artery,branches from the thoracoacromi al area,or perforating branches from deltoid muscle,were designed and raised according to scars and dominant vessels.The donor sites were closed at same time without skin graft.Results 43 patients with 51 flaps were operated for reconstruction of post burn faciocervical scars.All flaps and donor sites survived well.Conclusions Pre expanded deltopectoral flap is an ideal donor site for repairing post-burn faciocervical scars.

OBJECTIVE To investigate the effects of aerobic exercise on enteric nervous injury in rats exposed to malathion.METHODS Adult male Wistar rats were treated with non-load swi mming every other day,three ti mes a week,each one hour,for six weeks.Before exercise,the rats were trea-ted with malathion 100 mg·kg -1·d -1 by oral gavage,six days a week,for six weeks.The activities of seru m acetylcholinesterase(AChE)and butyrocholinesterase(BuChE)were determined.In addition,the s mall intestinal propulsion indexes were measured.Also,the distribution of nerve plexus in ileu m was observed.The i mmunohistoche mical method was used to measure the levels of protein gene-related petide 9.5 (PGP9.5),substance P (SP),and vasoactive intestinal peptide (VIP).RESULTS Co m-pared with normal control,malathion exposure decreased the activities of seru m AChE and BuChE (P<0.01 ),increased the s mall intestinal propulsion indexes (P <0.05).In addition,the levels of PGP9.5 decreased (P<0.05).At the sa me ti me,the levels of SP increased,and the levels of VIP decreased (P<0.05).Aerobic exercise did not change the activites of cholinesterases,but decreased s mall intes-tinal propulsion indexes,increased the levels of PGP9.5,decreased the levels of SP,and increased the levels of VIP.Co mpared with the malathion exposure only,the rats in malathion ad ministration co mbined with aerobic exercise group de monstrated much lower activites of cholinesterase (P <0.01 ),and the s mall intestinal propulsion indexes decreased fro m (89 ±4)% to (79 ±5)%(P <0.01 ).Moreover,the levels of PGP9.5 increased fro m 0.012 ±0.003 to 0.029 ±0.015 (P <0.01 ).At the sa me ti me,the levels of SP decreased fro m0.174 ±0.067 to 0.1 10 ±0.057(P<0.05),and the levels of VIP increased fro m 0.0076 ±0.0029 to 0.01 1 1 ±0.0047 (P <0.05).The levels of above para meters were sa me or close to those of the normal control.CONCLUSION Malathion exposure induced disorders of enteric nervous syste m in rats,and the aerobic exercise abated the toxic response in enteric nervous syste m of malathion exposure rats.However,these effects were not mediated through recovery of cholinesterases inhibition.

Replacement of diseased retinal pigment epithelium (RPE) cells with healthy RPE cells by transplantation is one option to treat several retinal degenerative diseases including age-related macular degeneration,which are caused by RPE loss and dysfunction.A cellular scaffold as a carrier for transplanted cells,may hold immense promise for facilitating cell migration and promoting the integration of RPE ceils into the host environment.Scaffolds can be prepared from a variety of natural and synthetic materials.Strategies,such as surface modification and structure adjustment,can improve the biomimetic properties of the scaffolds,optimize cell attachment and cellular function following transplantation and lay a foundation of clinical application in the future.

Objective To study the surgery effect on early application of toe flap to repair thumb severe electric bum.Methods From July 2007 to October 2017,a total of 25 cases of thumb severe electric burn were repaired by thumb toe flap grafting.The function of the finger after operation was evaluated comprehensively,and the effect of 72 hours before and after the injury was compared.Results All the flaps survived and the finger function was excellent.The excellent and good rate of 25 cases was 72％.The excellent and good rate of 72 hours before and after injury were 85.7％ and 54.5％ respectively.5 cases had bad wound complications after operation.1 cases were operated within 72 hours after injury,and 4 cases were operated after 72 hours.Conclusions The early application of toe flap to repair severe electric bum thumb can maximize the recovery of function of the thumb.The earlier the operation,the fewer complications,the better the repair effect.

Objective: To explore the choice of the donor site of flap and the repair method of secondary wound of flap donor site in tissue repair and reconstruction operation. Methods: From January 2014 to September 2018, 62 cases of scar contracture deformity, 15 cases of skin tumor, 20 cases of skin and soft tissue injury, and 25 cases of chronic wound were admitted to the Burn Center of People′s Liberation Army of First Affiliated Hospital of Air Force Medical University, with 84 males and 38 females, aged from 3 to 89 years. Four repair strategies adopted for tissue repair and reconstruction and good repair of the donor site of flap were as follows: designing the flap rationally according to the condition around the wound or the size and shape of wound, choosing pre-expanded technique of the donor site of flap for repair of scar deformity optimally, making full use of the surrounding condition of flap donor site, and repaired with the distal flap, i. e. replacing the important site with secondary site. The donor site of flap was repaired by direct suture or peripheral flap and distal flap. The wound size of patients ranged from 3.0 cm×2.0 cm to 20.0 cm×18.0 cm, and the flap area ranged from 3.5 cm×2.0 cm to 25.0 cm×22.0 cm. The survival condition of flap, healing condition of donor site and recipient site, and follow-up condition of donor site and recipient site were recorded. Results: Wounds of 122 patients were repaired with a total of 148 flaps designed by the above four repair strategies. All the flaps survived well, and the wound and flap donor site healed well. Follow-up for 3 to 36 months showed that the shape and function of recipient site and flap donor site were satisfactory. Conclusions According to the specific condition of the wound and anatomical structure of the surrounding tissue of flap donor site, overall surgical design with flexibility and personalization can achieve effects of good repair of the wound and reduce the secondary damage of flap donor site.

Objective:To evaluate the effect of goal-oriented online and offline mixed teaching method on the trainees of burn operating room.Methods:From June 2019 to June 2020, 42 trainees of burn operating room in our hospital were selected for the randomized parallel trial, and they were randomly divided into two groups, routine group and research group. The routine group adopted the conventional online and offline mixed teaching method, while the research group adopted the goal-oriented online and offline mixed teaching method. The internship time of both group lasted for 1 month. Results and excellent rates, self-confidence and burn surgery skills evaluation before and after the internship, and satisfaction with the internship mode were compared between the two groups. SPSS 19.0 was used for t test and chi-square test. Results:The results and excellent and good rates of theoretical examination and practical examination in the research group were higher than those of the routine group. The scores of self-confidence, choice of operation mode, innovation and optimization of operation, control of operation complications and treatment of intraoperative emergencies in the two groups after internship were higher than those before internship, and the above scores of research group were higher than those of the routine group after internship. The satisfaction scores of the students on enhancing self-confidence, and improving operational ability, learning initiative and learning efficiency in the research group were significantly higher than those in the routine group ( P < 0.05). Conclusion:Goal-oriented online and offline mixed teaching method on trainees in burn operating room can not only improve the examination results, enhance their confidence and burn surgery skills, but also achieve their satisfaction.