Objective: To investigate the effects of human amniotic epithelial stem cells-derived exosomes on healing of wound with full-thickness skin defect in rats. Methods: (1) Human amniotic epithelial stem cells were isolated from the amnion tissue of 5 full-term pregnant women in Department of Obstetrics of our hospital by the method of trypsin digestion, and their morphology was observed. The third passage of cells were stained with rhodamine-phalloidin for cytoskeleton observation. The third passage of cells were identified with flow cytometry through the detection of expressions of cell surface markers CD29, CD31, CD34, CD90, CD105, SSEA3, SSEA4 and immunity-related marker human leukocyte antigen-D related site (HLA-DR). The third passage of cells were also assessed the ability of adipogenic and osteogenic differentiation. (2) The third passage of human amniotic epithelial stem cells were cultured in DMEM medium supplemented with 10% exosome-free fetal bovine serum. Exosomes were isolated from culture supernatant by the method of ultracentrifugation and represented with scanning electron microscope for morphologic observation. (3) Six adult SD rats were anesthetized, and four 1 cm×1 cm sized wounds with full-thickness skin defect were made on the back of each rat. The wounds on the back of each rat were divided into control group, 25 μg/mL exosomes group, 50 μg/mL exosomes group, and 100 μg/mL exosomes group according to the random number table (with 6 wounds in each group), and a total volume of 100 μL phosphate buffered saline, 25 μg/mL exosomes, 50 μg/mL exosomes, and 100 μg/mL exosomes were evenly injected around the wound through multiple subcutaneous sites, respectively. The wound healing rate was calculated based on measurement on post injury day (PID) 7, 14, and 21. On PID 21, the healed wound tissue of each group was collected and stained with HE to observe and count skin accessories, and the arrangement of collagen fibers was observed with Masson staining. Data were processed with analysis of variance for repeated measurement, analysis of variance of randomized block design, one-way analysis of variance, and Bonferroni test. Results: (1) The cells, which were isolated and cultured, displayed typical cobblestone morphology with many microvilli on cell surface. Among the cells, the positive expression rates of CD29, CD90, SSEA3, and SSEA4 were above 50.0%, and the rate of CD105 was 8.0%, while the rates of CD31, CD34, and HLA-DR were almost 0. The cells could differentiate into adipocytes and osteoblasts. The above results revealed that the cells cultured were human amniotic epithelial stem cells. (2) Human amniotic epithelial stem cells-derived exosomes were round or oval vesicles with diameter from 50 to 150 nm. (3) On PID 7 and 21, wound healing rates of the four groups were close (with P values above 0.05). On PID 14, wound healing rates of 50 and 100 μg/mL exosomes groups were (89.8±4.3)% and (92.0±4.6)% respectively, significantly higher than the wound healing rate of control group [(80.3±6.4)%, P<0.05 or P<0.01]. Moreover, the wound healing rate of 100 μg/mL exosomes group was significantly higher than that of 25 μg/mL exosomes group [(83.3±5.1)%, P<0.05]. On PID 21, the numbers of skin accessories in 50 and 100 μg/mL exosomes groups were 4.3±1.4 and 5.1±1.6 respectively, obviously more than those of control group and 25 μg/mL exosomes group (respectively 1.4±0.5 and 1.8±0.6, with P values below 0.01). Well reorganized collagen fibers were observed just in the healed wound tissue of 50 and 100 μg/mL exosomes groups. Conclusions Human amniotic epithelial stem cells-derived exosomes can promote healing of wound with full-thickness skin defect in rats.

The clinical manifestations of colorectal polyps are consistent with the characteristics of dampness, stickiness and heaviness. The TCM constitutions in the prone population are mostly related to dampness. The pathological changes of intestinal flora imbalance, intestinal micro inflammation, neuroendocrine immune network and abnormal aquaporin in colorectal polyps are consistent with the research results of modern mechanism of dampness pathogen. This article believed that the TCM pathogenesis of colorectal polyps caused by damp pathogen is the accumulation of spleen deficiency and dampness caused by improper diet, poor emotion and other factors, and the interweaving of various diseases and pathogens to form tangible foreign bodies. According to the pathogenic characteristics of damp pathogen and the pathogenic factors of colorectal polyps, the influence of damp pathogen on the pathogenesis of colorectal polyps was discussed, in order to provide an effective TCM theoretical basis for the diagnosis and treatment of colorectal polyps in clinic.

Objective:To develop a grading system for necrosis of pedicled flaps in reconstruction of foot and ankle, and to verify its effectiveness and repeatability.Methods:A retrospective observational study was conducted. A total of 40 necroses of foot and ankle pedicled flaps were selected by 2 senior surgeons based on the flap surgery performed by the same surgical group in Department of Orthopaedic Surgery, the 920 Hospital of Joint Logistic Support Force of PLA from January 2010 to January 2022. A grading system for pedicled flap necrosis was proposed by a working group and the 40 necrotic flaps were graded. The coincidence rate was calculated to evaluate the effectiveness of the grading system through correlation studies between grading and clinical treatment. One photo of a typical postoperative necrotic flap was collected from each of the 40 flaps. Then 5 extramural surgeons were asked to grade the necroses shown on the photos according to the proposed grading system. Moreover, weighted Kappa analysis was performed on the results of proposed grading system and also on the standard grading currently in use, to evaluate the repeatability of the proposed grading system. Evaluated data were expressed by Mean±SD, and the coincidence rate was expressed by percentage. The reproducibility was studied by weighted Kappa analysis.Results:Of the 40 necrotic flaps, 7 flaps were classified in Grade I, 16 in Grade Ⅱ, 12 in Grade Ⅲ and 5 in Grade IV. In comparison with the actual treatment methods, the overall coincidence rate of the grading system was 92.5%. It indicated that the proposed grading system could effectively guide the selection of a treatment procedure. The average weighted Kappa coefficient of surgeons was at 0.628 with a 95% confidence interval (95%CI) between 0.460-0.796, which was strongly consistent with the standard of the grading system currently in use.Conclusion:The grading system for necrosis of pedicled flap in reconstruction of foot and ankle proposed in this study is simple and clear. It is able to effectively guide the treatment of flap necrosis. The preliminary validation shows that the classification system has good repeatability.

Amino Acid Motifs ; Bacterial Proteins ; chemistry ; Crystallography, X-Ray ; Klebsiella pneumoniae ; chemistry ; Protein Domains ; Transcription Factors ; chemistry