Improvements in severe burn and trauma care have enabled patients to survive massive bums and severe injury that would have once been fatal.Now up to 40％-70％ of patients develop hypertrophic scars after bums and trauma.The functional and psychosocial sequelae remain a major rehabilitative challenge,decreasing quality of life and delaying reintegration into society.So far,including surgical treatment,existing scar treatments have different degrees of limitations.In recent years,flap surgery and wound repair technology develop rapidly,such as perforator flap,flap dilation techniques,autologous scar composite skin,negative pressure wound treatment technology,the new technology of 3D and 4D bioprinting technology etc.These new technologies provide high quality tissue repair materials for clinical treatment of scar repair have a broad prospect of clinical application,and have achieved more satisfactory clinical repair treatment effect.The future need is to further strengthen the practice and innovation of scar repair,and the basic research and clinical application of scar should be strengthened and combined closely.The new elucidation of the scar prevention and therapeutic strategies should be put foward to improve the prognosis of patients with scar and the quality of life.

Objective To investigate the application of B -Learning mode in the teaching of department of burns surgery.Methods 234 students were divided into two parts by digital table method randomly.The experimental group was applied by the means of B -learning mode,while the control group was taught by the traditional way.And the results were evaluated.Results The basic theory scores(75.39 ±12.04)points in the students of experimental group were higher than those of the control group(68.27 ±12.38)points.The practice scores(76.42 ±11.89)points in the students of experimental group were higher than those of the control group(65.36 ±12.05)points.Students'professional knowledge scores(79.92 ±12.85)points in the experimental group were higher than those of the control group(71.56 ±13.01)points.Both percentage and score were higher in the experimental group than in the control group in comprehensive ability.Conclusion Blending learning gives students a potential time,environment and recourse to learn.By integrating learning ability and nursing skills improved,B -learning mode plays an important role in improving the quality of burn department internship.

Objective To explore the indications and curative effect of minimally invasive pedicle screw fix-ation in the treatment of thoracolumbar fractures .Methods 10 patients with thoracolumbar fractures without neuro-logical damage and the need for vertebral lamina decompression were selected .Under the C arm,the disease vertebral and adjacent vertebral arch spikes were positioned ,four 2.5cm long incisions were done ,fixation and restoration were completed within four small incisions .Results All patients restored vertebral body height and protrusion deformity after correction.The operation time was about 2h,blood loss was 100~150mL.Conclusion The minimally invasive pedicle screw fixation in the treatment of thoracolumbar fractures is suitable for simple thoracolumbar fractures without neurological damage ,the need for patients with vertebral lamina decompression ,it has advantages of small trauma ,fas-ter postoperative recovery .

To investigate the optimum transfection condition in transfecting human keratinocytes with plasmid-liposome complexes in vitro,the cultured human keratinocytes at 60% ～ 100% confluences were exposed to the eukaryotic expression plasmid,pCMV*SPORT-β-gal,coated with LipofectAMINE in different DNA/liposome mixing concentration ratios.After cultured for another 48 hours following the ends of 6 ～ 24 hours exposures to the DNA-liposome complexes,the transfected human keratinocytes were visualized by β-galactosidase staining.Then,the transfection efficiency was determined by calculating the rate of β-galactosidase staining positive cells.β-galactosidase expression was showed clearly in human keratinocytes transfected with the DNA-liposome complexes.The highest efficiency was achieved with cultured cells at 80% and 90% confluences,demonstrating by the transfection rates of (31.35±1.35)% and (32.32±2.47)% respectively.Meanwhile,the essential transfection conditions for these efficiencies were in coating pCMV*SPORT-β-gal DNA of 1.5μg/100μL with LipofectAMINE of 12.5μL/100μL,and exposing the cells to the DNA-liposome complexes for 8 hours.These results indicate that LipofectAMINE could effectively transfer eukaryotic expression plasmid into human keratinocytes in vitro,for which the optimization of transfection conditions involve in cells growth state,DNA/liposome mixing concentration ratio,and exposure time of cells to DNA-liposome complexes.

Hyperplastic scar and contracture are two mainly respects that contribute to poor functional recovery of the patients after burn.The principles of prevention and management of the scar were reviewed in the article and the methods in facilitating functional recovery were also discussed as well.

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 repair effect of the superficial iliac island flap for the hypertrophic scar of mons pubis after burned.Methods From July 2013 to July 2016,the author had treated 26 patients with mons pubis hypertrophic scar after burned.There were 19 males and 7 females among them.The age was from 1 year and 5 months to 10 years old.The scar area was of 6 cm ×5 cm-15 cm ×8 cm.Some of the patients had external genital malformations caused by scar contracture.Surgery removed the scar and completely released the basic shape of the vulva.It had to expand the superficial iliac island flap of 1 cm according to the size of the wound,and sufficient length of vascular pedicle according to the distance from the wound to the flap.The flap was cut in the superficial of the deep fascia,and reserved about 2cm wide fat along the superficial iliac artery.The superficial vein was located in the fat.The wound was covered by the flap,which was rotated directly or through a subcutaneous tunnel.Results Twenty six patients were treated with a single operation and no vascular crisis occurred.All the flaps survived.One patient delayed incision healing due to the high incision tension,and the remaining patients were in primary healing.The postoperative follow-up found that all the flaps had thin thickness,similar color to the surrounding skin,soft texture and feeling.Conclusions There are obvious signs of scarring in the mons pubis area after deep burns,and scar contracture can cause vulvar deformity.The superficial iliac island flap,which has a thin thickness,soft texture,similar color,and can be sutured directly for the donor site,is a good choice to repair the mons pubis hypertrophic scar.

Objective To evaluate operative methods and the clinical effect for comminuted calcaneal fractures.Methods 21 cases(24 feet)of comminuted calcaneal fractures were treated by one stage bone grafting plus open reduction and internal fixation with plastic calcaneus titanium plate.The fractures were classified according to the Sanders system into Sanders Ⅱ,Ⅲ and Ⅳ subgroups.Results All cases were followed up for 9～20 months(14months in average).All cases recovered with good healing of fracture.According to Maryland score,the results were excellent in 14 feet,good in 7 feet,fair in 2 feet,and poor in 1 foot.The excellent and good rate was 87.5％.Conclusions By using the method of internal fixation with plastic calcaneus titanium plate,fracture site can be well exposed,which is helpful to recover calcaneus to its normal length,width,height,Gissane angle and Bohler angle.A reliable internal fixation is helpful for early stage functional excise after surgery,which can maximize the recovery of the ankle function.

Objective:To observe the influence of different treatment intervals of pulsed dye laser (PDL) in treating hypertrophic scar of burn patients and to explore the optimal treatment interval.Methods:From May 2018 to March 2019 , 20 burn patients who met the inclusion criteria and admitted to the First Affiliated Hospital of Air Force Medical University were included in this prospective randomized controlled study. Patients were divided into 1 week group [4 patients, 2 males and 2 females, aged 27 (4, 67) years,19 scars], 2 weeks group [5 patients, 2 males and 3 females, aged 9 (3, 55) years, 15 scars], 3 weeks group [5 patients, 4 males and 1 female, aged 26 (19, 45) years,15 scars], and 4 weeks group [6 patients, 4 males and 2 females, aged 31 (14, 48) years,13 scars], according to the random number table, and treated with PDL with the treatment intervals of one week, two weeks, three weeks, and four weeks, respectively, and total treatment cycle of 3 months. Before the first treatment and three months after the first treatment, the Vancouver Scar Scale (VSS) was conducted and the decreased value of VSS score was calculated; the laser doppler blood flow meter was used to measure scar blood perfusion and the proportion of change in blood perfusion volume was conducted. Data were statistically analyzed with Kruskal-Wallis test, Wilcoxon rank sum test, Wilcoxon symbolic rank sum test, Bonferroni correction, and Fisher’s exact probability test.Results:The VSS scores of patients in 1 week group, 2 weeks group, 3 weeks group, and 4 weeks group in three months after the first treatment were significantly lower than those before the first treatment ( Z=-3.74, -3.47, -2.69, -3.25, P<0.01). There were no statistically significant differences in the decreased values of VSS scores in three months after the first treatment among the patients in 4 groups ( H=5.18, P>0.05). Three months after the first treatment, the blood perfusion volumes of patients in 2 weeks group and 3 weeks group were significantly lower than those before the first treatment ( Z=-2.95, -2.50, P<0.05). The proportions of changes in blood perfusion volume of patients in the 4 groups were respectively -0.02(-1.05-0.69), -0.29 (-0.75-0.18), -0.11 (-0.55-0.23), 0.05 (-0.61-0.75). There were statistically significant differences among the 4 groups ( H=9.39, P<0.05). The proportions of changes in blood perfusion volume of patients in 2 weeks group was statistically higher than that of 1 week group ( Z=2.76, P<0.01). Conclusions:PDL treatment can reduce the VSS score and blood perfusion volume of scar, the blood perfusion volumes of patients in 2 weeks group and 3 weeks group were significantly decreased, they can be recommended as the appropriate treatment interval of PDL for hypertrophic scar after burn.

OBJECTIVETo observe the effects of adipose-derived mesenchymal stem cells (ADSCs) with continous over-expression of glial cell line-derived neurotrophic factor (GDNF) on the motor function recovery and nerve regeneration of sciatic nerve of rats after electrical injury.

METHODSFive SD rats were collected to prepare ADSCs with over-expression of GDNF. One hundred and fifty SD rats were divided into normal control group (N), GDNF-ADSCs group (GA), ADSCs group (A), GDNF group (G), and physiological saline group (P) according to the random number table, with 30 rats in each group. Rats in group N were routinely fed without treatment, and rats in the other 4 groups were inflicted with electrical injury on sciatic nerve of thigh of the right hind leg. Rats in groups GA, A, G, and P were respectively injected with 100 µL suspension of ADSCs with over-expression of GDNF (1 x 10(7) cells per mL), 100 [µL ADSCs suspension (1 x 10(7) cells per mL), 100 µL GDNF solution (100 mg/L) , and 100 µL physiological saline to the surface of the injured nerves immediately after injury. Six rats of each group were collected for measuring hind limb stride from post injury week (PIW) 1 to 8, and morphology of the sciatic nerves was observed in PIW 8. In PIW 4, the protein expression of GDNF of sciatic nerves of the rest rats in each group was determined with Western blotting. Data were processed with one-way analysis of variance, analysis of variance of repeated measurement, and SNK test.

RESULTSCompared with that of group N, the hind limb stride values in groups GA, A, G, and P were significantly lower at each time point (with P values below 0.05). Compared with those of group P, the hind limb stride values in group GA from PIW 3 to 8, in group A in PIW 3, 5, and 7, and in group G in PIW 3, 5, 7, and 8 were significantly longer (with P values below 0.05). The hind limb stride values in group GA from PIW 4 to 8 were respectively (10.83 ± 0.97), (13.25 ± 1.40), (12.86 ± 1.42), (14.06 ± 1.50), and (15.09 ± 1.17) cm, which were significantly longer than those in group A [(8.90 ± 0.82), (9.03 ± 0.57), (9.27 ± 0.36), (9.86 ± 0.36), and (9.52 ± 0.58) cm] and group G [(8.87 ± 0.69), (8.51 ± 1.18), (9.34 ± 0.87), (9.76 ± 0.67), and (9.50 ± 1.22) cm], with P values below 0.05. Compared with that of group N, the number of myelinated nerve fibers of sciatic nerves was obviously decreased in group P but obviously increased in groups GA, A, and G; the diameter of axons was obviously shorter, and the myelin thickness was obviously increased in groups GA, A, G, and P in PIW 8 (with P values below 0.05). The number of myelinated nerve fibers in group GA was 31.2 ± 0.8, which was significantly higher than that in group A (23.7 ± 2.7), group G (22.3 ± 2.7), or group P (9.3 ± 2.8), with P values below 0.05. The diameter values of axons among groups P, A, G, and GA were similar (with P values above 0.05). The myelin thickness of rats in group GA was (3.41 ± 0.34) µm, which was significantly thicker than that in group A [(2.64 ± 0.37) µm] or group G [(2.41 ± 0.34) µm], with P values below 0.05. In PIW 4, the protein expression of GDNF of sciatic nerves was significantly higher in groups P, A, G, and GA than in group N (with P values below 0.05), and the protein expression of GDNF in group GA was significantly higher than that in group P, A, or G (with P values below 0.05).

CONCLUSIONSADSCs over-expressing GDNF protein can obviously promote the motor function recovery and nerve regeneration of sciatic nerve of rats after electrical injury.

Adipose Tissue ; Animals ; Electrophysiology ; Glial Cell Line-Derived Neurotrophic Factor ; genetics ; metabolism ; Mesenchymal Stem Cell Transplantation ; methods ; Mesenchymal Stromal Cells ; metabolism ; Nerve Crush ; Nerve Regeneration ; physiology ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; pathology ; physiology