Objective:To investigate the role of growth arrest specific protein 6 (Gas6) in regulating macrophage polarization in wound healing.Methods:Clean male B6 mice were randomly(random number) divided into the normal group, skin defect group, skin defect group + normal saline group (PBS group), skin defect + Gas6 (1 μg) group, skin defect + Gas6 (5 μg) group, and skin defect + Gas6 (10 μg) group. Ten mice in each group were used to observe the healing of skin wounds. Macrophages were isolated from the wound tissues of the remaining 6 mice on the fifth day after modeling. The levels of IL-6 and IL-10 were detected by enzyme-linked immunosorbent assay (ELISA), the mRNA expression levels of arginase-1 (Arg-1) and inducible nitric oxide synthase (iNOS) were detected by RT-PCR, and flow cytometry was used to detect the expression of M1 marker CD197, M2 marker CD163 and F4/80. HE staining was used to detect the pathological changes of skin wounds. Masson staining was used to analyze the granulation tissue and collagen deposition.Results:Scab began to form on the surface of the wound on the third day after the skin defect model was established. The wound area of the Gas6 treatment group was smaller than that of the PBS group, and the wound healing was better than that of the PBS group. Compared with the normal group, the proportion of CD197 in macrophages of the skin defect group was significantly increased ( P=0.00 49), the proportion of CD163 and F4/80 double positive was significantly decreased ( P=0.00 86), the level of IL-6 was significantly increased ( P=0.00 13), the level of IL-10 was significantly increased ( P=0.00 14), the level of iNOS mRNA was significantly increased ( P=0.00 8), and Arg-1 was significantly increased in the skin defect group The mRNA level was significantly decreased ( P=0.01 21), and the inflammatory infiltration was aggravated. Compared with the PBS group, the proportion of CD197 in the Gas6 treatment group was significantly decreased ( P=0.00 0), the double positive rates of CD163 and F4/80 were significantly increased ( P = 0.00 0), the level of IL-6 was significantly decreased (P = 0.00 0), the level of IL-10 was significantly increased ( P=0.00 03), the level of iNOS mRNA was significantly decreased ( P=0.00 18), the level of Arg-1 mRNA was significantly increased ( P=0.00 1), and the number of inflammatory cells and the number of collagen fibers were increased. Conclusions:Gas6 can promote the transformation of macrophages from M1 to M2 in mice with skin defect, which is beneficial to the wound healing of skin defect.

Objective: To explore the clinical effects of split-thickness scalp and allogenic acellular dermal matrix (ADM) in repairing deep wounds of hands in patients with extremely extensive burns. Methods: Six patients with extremely extensive burns complicated by deep burn in hands were admitted to our department from December 2014 to December 2017, including 4 males and 2 females, aged 21 to 58 years. Their total burn areas were from 85% to 95% total body surface area (TBSA), and the sum of deep-partial thickness and full-thickness wounds was larger than 50% TBSA. Under general anesthesia, deep wounds of 10 dorsal hands were repaired by combined transplantation of split-thickness scalp and allogenic ADM in 4 to 6 weeks after injury. The skin grafting range was beyond the metacarpophalangeal joint, including partial dorsal digital deep wounds. Survival of skin grafts on dorsal hands, follow-up of hand shape and functional recovery were observed and recorded. Results: Six patients were successfully treated. There was no infection on the dorsal deep wounds of 10 hands after surgery, and the grafts survived well. During follow-up of 1 to 2 years after operation, there were no recurrent tension blisters or dorsal extension deformity of the metacarpophalangeal joints in 10 hands, the shape and function of hands recovered well, and hand Carroll scores were from 90 to 99 points, with functional levels of Ⅴ and Ⅵ. Conclusions The combined transplantation of split-thickness scalp and allogenic ADM is a good method for repairing deep hand wounds in patients with extremely extensive burns, which can alleviate the cicatrix hyperplasia and contracture of healed hand wounds, and improve the shape and function of hands.

Objective To obtain the parameters of optimal spectral scanning mode in chest spectral CT imaging,radiation doses,image quality,CNR and subjective scores are compared in spectral and conventional scan modes with anthropomorphic chest phantom.Methods An anthropomorphic chest phantom underwent both conventional scan and spectral scan using three different protocols:GSI assist mode (protocol A);GSI mode with mean tube current (protocol B);GSI mode with maximum tube current (protocol C).All above scans were performed with the noise index (NI) as 9 and 11 respectively.The radiation dose was recorded,and the SD values of adipose tissue and muscle tissue of 5 different sections were measured in regions of interest (ROls) to evaluate the image quality.All scans were subjectively scored in 5 score system by two senior radiologists on lung markings and branches with the lung window technique.Results The effective dose (E) values of conventional CT scan and protocols A,B and C were 8.0,8.5,6.2,10.4 and 5.3,5.1,4.3,6.2 mSv.When NI =9,the difference of SD values had statistically significance between conventional scan and protocols A,C (F =4.496,P ＜ 0.05).When NI =11,there was statistically significant difference of SD value between conventional scan and protocols A,B,C (F =8.425,P ＜ 0.05).In conventional chest scan,the difference of SD values was statistically significant between NI =9 and 11 (t =-2.570,P ＜ 0.05),while other protocols had no statistically significant difference (P ＞ 0.05).The difference of CNR and subjective score had no statistically significance in either the same NI different scanning modes or the same scanning mode with different NIs.Conclusions Appropriate spectral scanning mode had no significant difference with conventional CT scanning in radiation dose,yet higher image quality can be obtained.Furthermore,appropriate NI can reduce the radiation dose obviously while the similar image quality was achieved.Considering the two factors,GSI assist mode can achieve balance between radiation dose and image quality.

Objective:To explore the application effect of rotating skin flap in the repair of skin and soft tissue defects in the perineum.Methods:A retrospective analysis was conducted on the data of 9 patients with perineal soft tissue defects treated in the Department of the First Affiliated Hospital, Wenzhou Medical University from January 2022 to March 2024. Among them, 8 cases were soft tissue defects after extensive resection of Paget′s disease in the perineum, and 1 case was soft tissue defects after treatment of severe urethral stricture. The defect area ranged from 4 cm×1.5 cm to 30 cm×35 cm, and all wounds were repaired with rotating skin flaps, For patients with excessive area, rotating skin flaps were used to cover important areas, combined with autologous skin and artificial skin to cover the remaining wounds. Patients with urethral stricture were treated with free oral mucosal reconstruction of the urethra combined with rotational skin flap coverage. The donor site was directly sutured or autologous skin was transplanted.Results:After surgery, the recipient skin flaps of 9 patients survived and the donor area healed. After a follow-up of 9-15 months, the skin flap survived well, with skin color approaching normal, and the donor site wound healed well. Eight patients with Paget′s disease did not show any recurrence, among which one patient with extensive wound expansion had good recovery of the perineal skin flap coverage area, and small-scale chronic ulcers appeared in the skin graft area. The skin flap of the patient with urethral stricture had recovered well, and the shape of the penis was good, without any urethral stricture, urinary fistula, sinus tract, etc.Conclusions:The rotational skin flap has a clear therapeutic effect on perineal soft tissue defects and is suitable for repairing perineal skin and soft tissue defects.