Objective: To establish a method for repairing extremities with extensively deep burn using large piece of fresh allogeneic scalp spliced by Meek glue combined with autologous microskin and observe its effect. Methods: Medical records of two male patients with extremely extensive deep burn admitted to our hospital from May to November in 2018 were retrospectively analyzed. Two patients aged 44 and 25 years respectively, with total burn area of 90% and 97% total body surface area (TBSA) and full-thickness burn area of 85% and 70% TBSA, respectively. Preoperatively, the surgical area on the extremities was calculated to estimate the necessary amount of allogeneic scalp and Meek miniature skin. The large piece of fresh allogeneic scalp spliced by Meek glue combined with autologous microskin was prepared according to the methods described as follows. Thin medium-thickness fresh scalps with 3% TBSA and 0.30-0.35 mm in depth were harvested from each donor and spliced into a large piece with epidermis upward by spraying Meek glue. Then the spliced scalp was punched after covered with a single-layer gauze. Autologous microskin was transported onto the dermis of fresh large piece of allogeneic scalp by traditional floating method. Bilateral extremities with full-thickness burn of two patients were selected for self-control. The left upper extremity was denoted as treatment group while the right upper extremity was denoted as control group in Patient 1. The right lower extremity was denoted as treatment group while the left lower extremity was denoted as control group in Patient 2. Wounds in the treatment group were treated with fresh large piece of allogeneic scalp spliced by Meek glue and autologous microskin with expansion ratio of 1∶15 after escharectomy, while wounds in control group received grafting of Meek miniature skin with expansion ratio of 1∶6 and or 1∶9 after escharectomy. The donors of allogeneic scalp were 32 males who were the relatives or friends of the patients, aged 21-50 years, with scalp area of (548±48) cm². The healing conditions of donor sites of scalp were observed on post operation day 10, and were followed up within 3 months after operation to observe whether forming alopecia and hypertrophic scar or not. Wound healing condition was evaluated during follow-up in post operation week (POW) 2-5 and 4 months after operation. Wound coverage rates were calculated in both treatment and control groups in POW 2, 3, 4, and 5. Results: The donor sites of all allogeneic scalp of donors healed completely on post operation day 10. There was no alopecia or hypertrophic scar within 3 months after operation for follow-up. In POW 2, allogeneic scalp grafts basically survived in treatment group without obvious exudation, and most of the Meek miniature skin survived in control group with obvious exudation. Part of allogeneic scalp grafts dissolved and detached in treatment group in POW 3, and the surviving grafts scabbed. The eschar detached and new epithelium was observed in treatment group in POW 4 and 5. In POW 3-5, surviving Meek miniature skin in control group creeped and was incorporated, and the wounds shrank. Hypertrophic scar was observed in both treatment and control groups 4 months after operation, without obvious difference in scar as a whole. The wound coverage rates were respectively 84%-98% and 76%-92% in treatment group of two patients in POW 2-5, close to or higher than those of control group (35%-97% and 28%-81%, respectively). Conclusions The study establishes a novel method for splicing fresh allogeneic scalps into a large piece as the covering of microskin, which has good effect for repairing extensively deep burn wounds. Considering that allogeneic skin is scarce, this method may be a new option in clinical treatment for extensively deep burn patients.

Objective: To explore the effects of scar excision combined with negative-pressure on repair of hypertrophic scar in burn children. Methods: From October 2010 to August 2016, 25 children with hypertrophic scar after deep burn were hospitalized, with scar course ranging from 3 months to 11 years and scar area ranging from 35 to 427 [83(51, 98)]cm². A total of 35 scars of 25 children were located in trunk (11 scars), upper limb (11 scars), and lower limb (13 scars). All children received scar excision operation and negative-pressure treatment (negative-pressure value ranged from -40 to -20 kPa), among which 6 cases received scar excision operation and negative-pressure treatment for two times for further removal of scars. After scar excision, electronic spring scale was used to measure the tension of the incision. The tension value of children ranged from 3.43 to 23.84 [7.16 (5.59, 9.12)] N, and then the incision was closed with appropriate suture according to the value of the tension. The incision with smaller tension was firstly opened on post operation day (POD) 8. After removing the suture, negative-pressure was conducted to POD 14. The incision with larger tension was firstly opened on POD 12. After removing the suture, biological semi-membrane was used to reduce tension to POD 16. All healed incisions were performed with anti-scar treatment for 1 year and relaxation and fixation for 3 months. General condition of the incision was observed after operation. The reduction percentage of scar area was calculated half-year after operation. The Patient and Observer Scar Assessment Scale was used to record the overall score of scar and scar score of trunk, upper limb, and lower limb before operation and half-year after operation. Data were processed with paired t test and Wilcoxon rank sum test. Results: After removing the suture, all incisions of children healed well without redness, effusion, and rupture. Half-year after operation, the appearance and deformity of incision were obviously improved, and the symptoms including pruritus and pain were basically relieved. Half-year after operation, the scar area of children ranged from 0 to 174 [21(9, 47)]cm^2, which was significantly decreased as compared with that before operation (Z=-5.16, P<0.05). The reduction percentage of scar area ranged from 36% to 100% [(73±19)%]. Half-year after operation, the overall score of scar and scar score of trunk, upper limb, and lower limb of children were obviously decreased as compared with those before operation (with t values from 6.42 to 17.37, P values below 0.05). Conclusions Scar excision combined with negative-pressure treatment has a good clinical effect on repair of hypertrophic scar in burn children, which is suitable for clinical application.

Objective:To investigate the expression and phosphorylation level change of adenosine monophosphate activated protein kinase (AMPK) in skeletal muscle of severely scald rats and its roles in skeletal muscle atrophy in severely scalded rats.Methods:The experimental research method was applied. Totally 100 6-week-old male Wistar rats were divided into sham injury group and scald group according to the random number table, with 50 rats in each group. After weighing the body weight, rats in scald group were inflicted with full-thickness scald of 30% total body surface area on the back, and rats in sham injury group were simulated with scald. At 6 h and on 1, 3, 5, and 7 d post injury, 10 rats in each group were taken to measure their body weights and weights of extensor digitorum longus and soleus muscle. At 6 h and on 1, 3, 5, and 7 d post injury, the tibialis anterior muscles were collected, the mRNA expressions of muscle atrophy F-box protein (MAFbx) and muscle-specific RING finger protein 1 (MuRF1) were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction; the content of adenosine monophosphate (AMP), adenosine diphosphate, and adenosine triphosphate (ATP) were detected by high performance liquid chromatography, and AMP/ATP ratio and energy charge were calculated; the protein expressions of AMPK-α and phosphorylated AMPK-α (p-AMPK-α) were detected by Western blotting, and the p-AMPK-α/AMPK-α ratio was calculated, with sample number of 4 in each time point of each group. Data were statistically analyzed with analysis of variance for factorial design and least significant difference test.Results:The body weights of rats in 2 groups before injury and at each time point post injury were close ( P>0.05). At 6 h post injury, the weight of extensor digitorum longus of rats in scald group was (0.107±0.007) g, which was significantly heavier than (0.086±0.0607) g of sham injury group ( P<0.01). On 3 d post injury, the weight of extensor digitorum longus of rats in scald group was (0.083±0.016) g, which was significantly lighter than (0.102±0.005) g of sham injury group ( P<0.01). The weight of soleus of rats in 2 groups were close at each time point post injury ( P>0.05). Compared with those of sham injury group, the mRNA expression of MAFbx in tibialis anterior muscle of rats in scald group was significantly up-regulated at 6 h post injury ( P<0.01), and the mRNA expressions of MuRF1 in tibial anterior muscle of rats in scald group were significantly up-regulated at 6 h and on 1 d post injury ( P<0.01). At 6 h and on 7 d post injury, compared with those of false injury group, the AMP/ATP ratios of the tibial anterior muscle of rats in scald group were significantly increased ( P<0.05 or P<0.01), and energy charges of the tibial anterior muscle of rats in scald group were significantly decreased ( P<0.01). At each time point post injury, the protein expressions of AMPK-α of the tibial anterior muscle of rats in 2 groups were close ( P>0.05). The p-AMPK-α/AMPK-α ratios of the tibial anterior muscle of rats in scald group at 6 h and on 7 d post injury were significantly higher than those in sham injury group ( P<0.05 or P<0.01). Conclusions:The decrease in energy charge and increase in AMP/ATP ratio of skeletal muscle of rats after severe scald activate AMPK. The activation of AMPK in the early stage of injury is consistent with the up-regulation of MAFbx and MuRF1 expressions and down-regulation of skeletal muscle weight. The above-mentioned changes may be one of the molecular mechanisms of skeletal muscle atrophy in rats with severe scald