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 effeets of insulin on the apoptosis of vascular endothelial cells cuinduced by burn$eruln in order to explore its possible mechamsm.Method Cultured human ECV304 cells were randomly divided into 33x)ups:control group,the ECV304 cells hured by 15%(V/V)rat normal,qertlm(t=6);bum semm group,the ECV3()4 cells simulated by 15%(V/V)self-made burn semm collected from rats with 30%TBSA full-thickness burns on the,back(n=6);and burn Serum+insulin group.the ECV304 cells cultared by insulin(10-7mol/L)and 15%(V/V) seIf-made rat bum serum(n=6).The transferase mediated nick end labeling(TUNEL) method was employed to measure the apoptosis of endothelial cells at 6 hours after stimulation.Meanwhile.immanohistochemical technique and Western blotting were used to determine the protein expressions of bcl-2 and eNOS.Data are expressed ills mean ±SEM.Statistical comparison was made using oneway analysis of vtriance.Significance was accepted at P<0.05.Results Compswith the control group,bum$erunl induced the apoptusis(18.5±3.1%)and down-regalated bcl·2(O.36±0.12)and p-eNOS(O.55±0.28)protein expressions of HUVECs(P<0.01).Burn 9AJ'unl+insulin significantly decreased the apoptosis(9.6 4-2.8%)and up-regulated bcl-2(0.944-0.25)and p-eNOS(0.89±0.16)protein expressions ofHU-VECs in comparison with the bum serllm group(P<0.01).eNOS showed no significant differences in three groups.Conclusions Insulin could markedly inhibit the apoptosis and up-regalate bcl-2 protein expression of HUVECs induced by bum serum,and its mec,harfism might involve the protein expression ofphosphorylated eNOS.

OBJECTIVETo observe the level of intracellular reactive oxygen species (ROS) in rats with severe burn and pulmonary microvascular endothelial cells (PMVECs) treated with serum of rat with burn injury, and to investigate the relationship between ROS and apoptosis of PMVECs.

METHODS(1) Twenty-four SD rats were divided into sham injury group ( n = 3) and burn group (n = 21) according to the random number table (the same grouping method below). Rats in burn group were inflicted with 30% TBSA full-thickness scald on the back, and rats in sham injury group were sham injured. Blood samples were collected from abdominal aorta at post injury hour 6, 12, 24, 36, 48, 60, 72 respectively from 3 rats of burn group. The serum content of ROS was assayed by ELISA. The same determination was performed in rats of sham injury group. (2) Five rats were subjected to scald injury as above, and burn serum was prepared 24 hours after injury. Another 5 rats without receiving any treatment were used to prepare normal serum. (3) Marginal pulmonary tissue was harvested from 20 SD young rats. Cells were cultured with tissue block method and indentified with immunohistochemical staining. The third passage of PMVECs in logarithmic phase were inoculated in 6-well plates and 12-well plates. PMVECs in both plates were divided into 4 groups: normal serum group, burn serum group, normal serum + MnTBAP group, and burn serum + MnTBAP group, with 3 wells in each group. Cells in the former 2 groups were respectively cultured with special nutrient solution of endothelial cells without serum added with 15% healthy rat serum or 15% burn rat serum. Cells in the latter 2 groups were cultured with the same culture conditions as in the former two groups correspondingly with addition of 100 µmol/L MnTBAP in the nutrient solution. After being cultured for 24 h, the content of ROS in PMVECs in 6-well plates was detected with flow cytometry. The apoptosis of PMVECs in 12-well plates was observed with acridine orange-ethidium bromide staining, and the apoptosis rate was calculated. Data were processed with one-way analysis of variance and LSD-t test.

RESULTS(1) The serum contents of ROS in rats of burn group were respectively (187 ± 21), (235 ± 22), (231 ± 25), (291 ± 20), (315 ±23) nmol/mL at post injury hour 24, 36, 48, 60, 72, which were significantly higher than that in sham injury group [(141 ± 19) nmol/mL, with t values respectively 7. 86, 9. 57, 13. 87, 14.98, 18.40, P values below 0.01]. (2) Primary cells grew slowly and showed a cobblestone appearance. After passages, cells grew with orderly distribution. The positive rate of coagulation factor VIII of cells was (96 ± 5)% , and thus they were identified as PMVECs. (3) In normal serum group, burn serum group, normal serum + MnTBAP group, and burn serum + MnTBAP group, the contents of ROS in PMVECs were respectively 798 ± 40, 1 294 ± 84, 763 ± 59, 926 ± 42 ( F =93.01, P <0.01), and the apoptosis rates of PMVECs were respectively (6.2 ± 1.3)%, (57.3 ± 6. 7)%, (3.7 ± 0. 8)%, (28.7 ± 5. 7)% (F = 224.50, P <0.01) after being cultured for 24 h. Compared with those of normal serum group, the content of ROS and apoptosis rate of PMVECs in burn serum group increased significantly (with t values respectively 10.40 and 49.06, P values below 0.01). The content of ROS and apoptosis rate of PMVECs in burn serum + MnTBAP group were significantly lower than those in burn serum group (with t values respectively 7.48 and 23.94, P values below 0.01).

CONCLUSIONSSerum content of ROS was increased in severely burned rats. Burn rat serum stimulation on PMVECs can lead to the increase of the intracellular ROS and induce apoptosis. However application of MnTBAP can scavenge ROS and reduce the apoptosis induced by burn rat serum.

Animals ; Apoptosis ; Burns ; blood ; therapy ; Endothelial Cells ; pathology ; Enzyme-Linked Immunosorbent Assay ; Lung ; blood supply ; Oxygen ; Rats ; Reactive Oxygen Species ; blood ; Serum ; metabolism

OBJECTIVETo investigate the potential therapeutic effect of tamoxifen in treating abnormal skin scar contraction.

METHODSFibroblast-populated collagen lattices, which were made by embedding human dermal fibroblasts within type I collagen forming a three-dimensional culture system, were used as an invitro model. Then media either without or with addition of tamoxifen from 1 mumol/L to 50 mumol/L were added to the collagen lattices. Lattice areas were measured at intervals to assess the influence of tamoxifen on the lattice contraction. To visualize changes in the morphology and vitality of fibroblasts, MTT was added to the lattices.

RESULTSTamoxifen had an inhibitory effect on lattice contraction by a dose- and time-dependent pattern. 5 mumol/L or less of tamoxifen didn't show any influence on lattice contraction but 30 mumol/L or higher completely inhibited contraction. At intermediate concentrations from 10 mumol/L to 20 mumol/L the degree of lattice contraction was dose- and time-dependent, which was demonstrated by the reversibility of inhibition. Both the inhibition of contraction and the reversibility of inhibition appeared to correlate with changes in fibroblast morphology.

CONCLUSIONTamoxifen could inhibit the contraction of fibroblast-populated collagen lattices, indicating that tamoxifen may have potential effect on abnormal scar contraction in vivo.

Cicatrix ; drug therapy ; Collagen ; physiology ; Dose-Response Relationship, Drug ; Fibroblasts ; drug effects ; physiology ; Humans ; Skin ; cytology ; drug effects ; Tamoxifen ; pharmacology ; therapeutic use ; Time Factors

OBJECTIVETo lower down the antigenicity of heterogenous swine acellular dermal tissue, and to explore the feasibility of clinical using it as a composite graft for human patients.

METHODSSplit-thickness skin was harvested from healthy swines and then processed by two methods. The swine acellular dermal matrix (sADM) was prepared by removing cells from the skin with trypsin and Triton X-100. Then the cross-linked sADM (sADM(1)) and non-cross-linked sADM (sADM(0)) were embedded subcutaneously in rabbits and also transplanted onto the burn wounds of patients. The histological changes and also transplantation results were observed.

RESULTS(1) In animals with sADM(0) embedded subcutaneously, the grafted tissue was invaded immediately by host cells with obvious inflammatory reaction and tissue degradation. But there was less inflammatory reaction, and with no obvious skin degradation and contraction with sADM(1). (2) In ten burn patients with III degree burn wounds and one patient with wound in chest after scar removal, sADM and ultra-thin skin (UTS) composite graft were grafted on the wounds with autologous thin skin (ATS) and autologous razor-thin or UTS as the control. Nineteen pieces of composite skin of sADM with UTS were grafted on the wounds with survival rate of 78.9%, exhibiting no evident difference with that of ATS. When sADM(0) and UTS were grafed, there exhibited remarkable early inflammatory reaction and wound contraction with similar external appearance with that of UTS. Whereas when sADM(1) and UTS were grafted, there appeared less early inflammatory reaction and wound contraction, resulting in an even appearance and soft to touch similar to that with ATS. But ulceration occurred, with exposure of sADM(1), exposure and severe macrophage reaction to foreign body in 6 wounds of 3 cases 12.8 +/- 6.9 weeks after sADM(1) and UTS grafting.

CONCLUSIONGrafting of sADM as a dermal substitute of composite skin could alleviate early post-grafting immune reaction and improve UTS grafting results. But the delayed graft rejection couldn't be avoided.

Animals ; Burns ; surgery ; Dermatologic Surgical Procedures ; Dermis ; immunology ; transplantation ; Humans ; Rabbits ; Skin ; immunology ; injuries ; Skin Transplantation ; methods ; Skin, Artificial ; Swine ; Time Factors ; Transplantation, Heterologous ; Wound Healing

Objective: To explore the effects of using free transplantation of expanded perforator flaps in the treatment of severe scar contracture deformities in children. Methods: From January 2010 to December 2018, 18 pediatric patients with severe scar contracture were admitted to Xijing Hospital of Air Force Medical University, and 3 pediatric patients with severe scar contracture were admitted to Shenzhen Hospital, Southern Medical University. There were 14 males and 7 females among the 21 pediatric patients, who were 3-12 years old, with 15 cases of cervicothoracic adhesion, 5 cases of chin-chest adhesion, and 1 case of ankle joint contracture. According to the location of scar contracture and the size of wound after release, the donor site of perforator flap and expander volume were selected, and the expander was inserted to expand the flap. After expanding to proper volume, the contracted scar was resected and released. The perforator flap was designed and transplanted freely according to the wound. The flap area ranged from 14 cm×6 cm to 18 cm×15 cm. The location of the expanded flaps, the number, location, rated volume, and the location of injection port of the inserted expanders, the survival condition of flaps, the complications, the repair of donor sites, and the follow-ups were analyzed. Results: Among this group of pediatric patients, 16 cases used expanded thoracodorsal artery perforator flap, 3 cases used expanded circumflex scapular artery perforator flap, and 2 cases used expanded anterolateral thigh perforator flap, with 14 cases of pure donor site expansion and 7 cases of donor site expansion together with expansion beside donor site. Thirty-four expanders were inserted in 21 pediatric patients, with 21 under flaps, 6 near scars, and 7 near donor sites. The rated volumes of 26 expanders were 200 mL, while those of the remaining 8 expanders were 400 mL. Eight injection ports were placed externally, while the rest were placed internally. All the 21 flaps survived completely. Vascular crisis occurred in 1 pediatric patient 5 days after operation, and exploratory operation and reanastomosis were performed. The donor sites of 19 pediatric patients were closed directly, while the small wounds in lateral thoracic donor sites of 2 pediatric patients were repaired with thin intermediate split-thickness skin graft collected beside the donor site. Follow-up for 6 to 36 months showed that the texture and color of area repaired by the flaps were close to the surrounding skin. The flaps in the neck region of 8 pediatric patients were slightly bulky, requiring debulking operation, while the other cases had good appearance. The movement function of the involved regions was basically restored to normal, and no recurrence of contracture occurred. Conclusions Free transplantation of expanded perforator flaps can achieve favorable appearance, texture, and function restore in treating severe scar contracture deformities in children, and the curative effect is stable and lasts long.