Characteristics of changes in volatile organic compounds and microbial communities during the storage of pickles.

The variations of volatile organic compounds (VOCs) and microbial communities of three pickles during storage at 4°C for one week were analyzed by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS), high-throughput sequencing, and Spearman correlation analysis. A total of 50 VOCs were identified from three pickles. During storage, most alcohols, aldehydes, ketones, and esters decreased, while acids increased, and sulfides, alkenes, and phenols were relatively equal. Firmicutes, Cyanobacteria, and Proteobacteria were the predominant bacterial phyla, and Weissella, Streptophyta, Leuconostoc, Bacillariophyta, and Lactobacillus were the predominant bacterial genera in three pickles. The bacterial diversity level significantly decreased during storage (P < 0.05). Spearman correlation coefficient indicated that Leuconostoc, Lactobacillus, and Weissella were highly correlated with the flavor of pickles, while Bacillariophyta and Streptophyta were highly correlated with the flavor formation of pickles during storage. These results could contribute to a better understanding of the impact of bacteria in flavor formation during pickle storage.

Tension-reduced closure of large abdominal wall defect caused by shotgun wound: A case report.

BACKGROUND: Large abdominal wall defect (LAWD) caused by shotgun wound is rarely reported. CASE SUMMARY: Herein, we describe a case of LAWD caused by a gunshot wound in which the abdominal wall was reconstructed in stages, including debridement, tension-reduced closure (TRC), and reconstruction with mesh and a free musculocutaneous flap. During a 3-year follow-up, the patient recovered well without hernia or other problems. CONCLUSION: TRC is a practical approach for the temporary closure of LAWD, particularly in cases when one-stage abdominal wall restoration is unfeasible due to significant comorbidities.

Adipose extracellular matrix promotes skin wound healing by inducing the differentiation of adipose­derived stem cells into fibroblasts.

Fibroblasts are the major effector cells of skin wound healing. Adipose­derived stem cells can differentiate into fibroblasts under certain conditions. In the present study, it was hypothesized that adipose­derived stem cells (ADSCs) could be induced by the adipose extracellular matrix (ECM) to differentiate into fibroblasts in order to promote skin wound healing. First, flow cytometry was used to detect the ratio of fibroblasts and relative expression of the fibroblast markers cytokeratin 19 (CK19) and vimentin in ADSCs. Then, the effect of the adipose ECM during the differentiation of ADSCs into fibroblasts was investigated by detecting the total amount of collagen fibers and degree of fibrosis, and the proliferation and cell cycle of differentiated fibroblasts, using the MTT assay and flow cytometry analysis respectively. Finally, a mouse skin wound model was established and treated with PBS, ADSC suspension or ECM + ADSCs to compare wound healing rate and expression of collagen I and collagen III by immunohistochemistry. Following induction of ADSCs with the adipose ECM, more fibroblasts were found, expression of CK19 and vimentin increased, and a greater degree of fibrosis occurred, which revealed the positive effect of the adipose ECM on the differentiation of ADSCs into fibroblasts. In addition, the induced fibroblasts had enhanced proliferation activity, with more cells in the S phase and fewer in the G2/M phase. The in vivo experiment indicated that the ECM produced by the ADSCs had a faster wound healing rate and increased expression of collagen I and collagen III compared with mice injected with PBS or ADSCs alone, which verified that ADSCs induced by the adipose ECM had a positive effect on skin wound healing. The present study demonstrated that the adipose ECM in combination with ADSCs may be a novel therapeutic target for the repair of skin injury, due to the ability of the adipose ECM to induce the differentiation of ADSCs into fibroblasts and to facilitate the wound healing process.

Adipose mesenchymal stem cell-derived exosomes stimulated by hydrogen peroxide enhanced skin flap recovery in ischemia-reperfusion injury.

BACKGROUND: Mesenchymal stem cell (MSC)-derived exosomes have been recognized as new candidates for the treatment of ischemic disease or injury and may be an alternative treatment for cell therapy. This aim of the study was to evaluate whether exosomes derived from adipose mesenchymal stem cell (ADSC) can protect the skin flap during ischemia-reperfusion (I/R) injury and induce neovascularization. METHODS: To investigate the effects of exosomes in the I/R injury of flap transplantation in vivo, flaps were subjected to 6 h of ischemia by ligating the left superficial inferior epigastric vessels (SIEA) followed by blood perfusion. Exosomes derived from normal ADSC (ADSC-exos) and exosomes derived from ADSC preconditioned with H2O2 (H2O2-ADSC-exos) were injected into the flaps. Then, the blood perfusion unit (BPU) of the flaps was measured by Laser Doppler Perfusion Imaging (LDPI) and microvessel density was determined by the endothelial with cell marker CD31 with Immunohistochemistry (IHC) staining. Inflammatory cell infiltration of the skin flap and apoptosis were detected by hematoxylin & eosin staining (H&E) and the TdT-mediated biotinylated dUTP nick end-labeling (TUNEL) technique. RESULTS: In vivo, exosomes significantly increased flap survival and capillary density compared to I/R on postoperative day 5, and decreased the inflammatory reaction and apoptosis in the skin flap (P < 0.05). Furthermore, H2O2-ADSC-exos had better outcomes compared to normal exosomes (P < 0.05). ADSC-exos could significantly increase human umbilical vein endothelial cell (HUVEC) proliferation (P < 0.05), but no statistic difference was found in exosomes derived from different microenvironments (P > 0.05). HUVEC co-cultured with H2O2-ADSC-exos increased the migration ratio and generated more cord-like structures compared to ADSC-exos and the control group (P < 0.05). CONCLUSION: ADSC-exos can enhance skin flap survival, promote neovascularization and alleviate the inflammation reaction and apoptosis in the skin flap after I/R injury. The use of a specific microenvironment for in vitro stem cell culture, such as one containing a low concentration of H2O2, will facilitate the development of customized exosomes for cell-free therapeutic applications in skin flap transplantation.

Co-transplantation of exosomes derived from hypoxia-preconditioned adipose mesenchymal stem cells promotes neovascularization and graft survival in fat grafting.

BACKGROUND: Adipose-derived stromal cells (ADSCs)-derived exosomes (ADSC-Exos) account for the proangiogenic potential of stem cell. This study aimed to investigate the effect of ADSC-derived exosomes (ADSC-Exos) on the survival in fat grafting. METHODS: A nude mouse model of subcutaneous fat grafting was adopted. Hypoxic preconditioned ADSC-Exos and ADSC-Exos were injected around the grafted tissue. The fat graft sample was weighed and examined by hematoxylin and eosin (H&E) staining and immunohistochemistry. Laser Doppler flowmetry and CD31 immunofluorescence staining were used to analyze neovascularization. RESULTS: ADSC-Exo and hypoxic ADSC-Exo groups had a significantly higher weight of fat graft and more perilipin-positive adipocytes than the control groups from 2 to 8 weeks after grafting, and the hypoxic ADSC-Exo group had better outcomes (all P < 0.05). H&E staining showed that ADSC-Exos attenuated infiltration of inflammatory cells around the fat grafts. Laser Doppler flowmetry showed that the two ADSC-Exo groups had better blood perfusion in the graft tissue than the control groups (all P < 0.05). Immunofluorescence demonstrated that the hypoxic ADSC-Exo group had significantly more CD31-positive cells than the ADSC-Exo group. In vitro study showed that hypoxic ADSC-Exos treatment significantly increased the migration (at 12 and 24 h) and in vitro capillary network formation (at 12 h) in the human umbilical vein endothelial cells (HUVECs) as compared with the ADSC-Exo group and control group (all P < 0.05). CONCLUSIONS: Co-transplantation of ADSC-Exos can effectively promote the survival of graft, neovascularization and attenuated inflammation in the fat grafts. Hypoxia treatment can further enhance the beneficial effect of ADSC-Exos.