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Background: Due to vasculature injury and increased oxygen consumption, the early wound microenvironment is typically in a hypoxic state. We observed enhanced cell migration ability under early short-term hypoxia. CCL2 belongs to the CC chemokine family and was found to be increased in early hypoxic wounds and enriched in the extracellular signal-regulated kinase (ERK)1/2 pathway in our previous study. However, the underlying mechanism through which the CCL2-ERK1/2 pathway regulates wound healing under early short-term hypoxia remains unclear. Activation of epithelial-mesenchymal transition (EMT) is a key process in cancer cell metastasis, during which epithelial cells acquire the characteristics of mesenchymal cells and enhance cell motility and migration ability. However, the relationship between epithelial cell migration and EMT under early short-term hypoxia has yet to be explored. Methods: HaCaT cells were cultured to verify the effect of early short-term hypoxia on migration through cell scratch assays. Lentiviruses with silenced or overexpressed CCL2 were used to explore the relationship between CCL2 and migration under short-term hypoxia. An acute full-thickness cutaneous wound rat model was established with the application of an ERK inhibitor to reveal the hidden role of the ERK1/2 pathway in the early stage of wound healing. The EMT process was verified in all the above experiments through western blotting. Results: In our study, we found that short-term hypoxia promoted cell migration. Mechanistically, hypoxia promoted cell migration through mediating CCL2. Overexpression of CCL2 via lentivirus promoted cell migration, while silencing CCL2 via lentivirus inhibited cell migration and the production of related downstream proteins. In addition, we found that CCL2 was enriched in the ERK1/2 pathway, and the application of an ERK inhibitor in vivo and in vitro verified the upstream and downstream relationships between the CCL2 pathway and ERK1/2. Western blot results both in vivo and in vitro demonstrated that early short-term hypoxia promotes epidermal cell migration by activating the CCL2-ERK1/2 pathway and EMT during wound healing. Conclusions: Our work demonstrated that hypoxia in the early stage serves as a stimulus for triggering wound healing through activating the CCL2-ERK1/2 pathway and EMT, which promote epidermal cell migration and accelerate wound closure. These findings provide additional detailed insights into the mechanism of wound healing and new targets for clinical treatment.
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As an effective flux, CaF2 is beneficial in improving the fluidity of slag in the steel-making process, which is crucial for dephosphorization. To reveal the existence form and functional mechanism of CaF2 in phosphosilicate systems, the microstructures and transport properties of CaO-SiO2-CaF2-P2O5 quaternary slag systems are investigated by molecular dynamics simulations (MD) combined with experiments. The results demonstrate that the Si-O coordination number does not vary significantly with the increasing CaF2 content, but the P-O coordination number dramatically decreases. CaF2 has a minor effect on the single [SiO4] but makes the structure of the silicate system simple. On the contrary, F− ions could reduce the stability of P-O bonds and promoted the transformation of [PO4] to [PO3F], which is beneficial for making the P element-enriched phosphate network structure more aggregated. However, the introduction of CaF2 does not alter the tetrahedral character of the original fundamental structural unit. In addition, the results of the investigation of the transport properties show that the self-diffusion coefficients of each ion are positively correlated with CaF2 content and arranged in the order of F− > Ca2+ > O2− ≈ P5+ > Si4+. Due to CaF2 reducing the degree of polymerization of the whole melts, the viscosity decreases from 0.39 to 0.13 Pa·s as the CaF2 content increases from 0% to 20%. Moreover, the viscosity of the melt shows an excellent linear dependence on the structural parameters.
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Objective: To evaluate the efficacy and adverse reactions of arthroscopic half-moon plate invasive surgery (DEB) in patients with knee pain (AKP) using meta-analysis techniques. Methods: The computer retrieves from the English databases PubMed, EMBASE, Cochrane Library, and Web of Science and the Chinese databases China Knowledge Network, Wanfang Database, VIP Database, and China Biomedical Literature Database to collect information about DEB therapeutic AKP randomized controlled trial. Develop criteria for documentation inclusion and exclusion, evaluate the quality and bias risk of literature, and compare differences in efficacy and adverse responses before and after DEB treatment and other conservative treatments. Results: A total of 14 randomized controlled trials and 1464 AKP patients were included in the study, with follow-up duration of 1-12 months. The total knee scores for DEB at 1, 3, 6, and 12 months after treatment were significantly better than baseline levels (1 month: WMD = 34.56, P = 0.02; 3 months: WMD = 27.73, P = 0.0001; 6 months: SMD = 2.38, P = 0.0001; 12 months: SMD = 1.69, P = 0.001). At 6 months of follow-up, DEB improved knee function better than HA (SMD = 0.47, P = 0.003), and during follow-up for 12 months, DEB relieved knee pain (SMD = 0.55, P = 0.0007) and improved knee function (SMD = 0.88, P = 0.0001) which is significantly better than HA. DEB was less effective at improving knee function in 1, 3, and 12 months than DEB joint HA injections (1 month P = 004; 3 months P = 0.01; 12 months P = 0.03). At 6 and 12 months of follow-up, DEB was better at pain relief and improved function than ozone (P > 0.05). DEB and glucocorticosteroids have similar effects in pain relief and improved function at various follow-up times. In terms of adverse reactions, DEB does not increase the risk of adverse events compared to HA (OR = 0.96, P = 0.85). Conclusion: Compared to HA and ozone, DEB is a more effective treatment for AKP joints, while DEB is combined with HA. The clinical efficacy of injection therapy AKP is better than that of DEB alone.
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OBJECTIVE: To explore clinical effect of infrared thermal imaging technology for the treatment of free anterolateral thigh perforator flap transplantation. METHODS: From June 2014 to June 2018, 31 patients with skin defect at various degrees treated by free anterolateral thigh perforator flap transplantation, including 21 males and 10 females aged from 16 to 59 years old with an average age of(35.3±1.5) years old, the courses of disease ranged from 2 to 4 weeks with an average of (1.8±0.6) weeks. The number of perforating branch, the position of the perforating branch, the perforating branch vitality detected by Doppler blood stream detector and parameters of thermal imaging image in order to guide design of skin flap, and compared results with the data of perforator arteries observed during the operation. RESULTS: Totally 52 branches of perforating arteries were detected by Doppler blood stream detector during operation, and 38 perforator branches were confirmed in operation, the accuracy rate was 73.1%. Thirty-eight branches of perforating arteries were detected by infrared thermography during operation, and 35 branches of perforating branches were confirmed in operation, the accuracy rate was 92.1%; there were statistical difference. The most dynamic perforating pivot found by Doppler blood stream detector was confirmed by intraoperative diagnosis, with an accuracy rate of 80.6%. The most dynamic perforating pivot found by infrared thermography is confirmed by intraoperative diagnosis, with an accuracy rate of 100%; there were statistical difference. Thirty-one flaps were survived without vascular crisis occurred. All patients were followed up from 6 to 18 months with an average of(10.7±1.2) months. The flaps survived with soft texture and good blood circulation, the defect was not bloated, the color of skin flap was basically the same as that of the normal skin, and the limbs appearance and function recovered well. CONCLUSIONS: Infrared infrared thermal imaging technology could be used as a new technology in localization of perforator artery in free anterolateral thigh perforator flap transplantation.
