Bone Marrow Mesenchymal Stem Cells-Derived Exosomes Promote Survival of Random Flaps in Rats through NRF2-Mediated Antioxidative Stress.

BACKGROUND: Random flaps are the most used defect repair method for head and neck tumors and trauma plastic surgery. The distal part of the flap often undergoes oxidative stress (OS), ultimately leading to flap necrosis. Stem cells exosomes exhibit potential effects related to anti-inflammatory, regenerative, and antioxidant properties. Nuclear factor erythroid-2-related factor 2 (Nrf2) is an important factor in regulating oxidative balance. Exosomes have been reported to monitor its transcription to alleviate OS. This study examined the impacts and underlying mechanisms of antioxidant actions of exosomes derived from bone marrow mesenchymal stem cells (BMSCs-Exo) on random flaps. METHODS: BMSCs-Exo was injected into the tail veins of rats on days 0, 1, and 2 after surgery of random flaps. The rats were euthanized on day 3 to calculate the survival rate. Immunohistochemical staining, western blotting, dihydroethidium probe, superoxide dismutase, and malondialdehyde assay kits were used to detect OS level. Human umbilical vein endothelial cells were co-cultured with BMSCs-Exo and ML385 (an inhibitor of Nrf2) in vitro. RESULTS: BMSCs-Exo may significantly improve the survival rate of the random flaps by reducing apoptosis, inflammation, and OS while increasing angiogenesis. Besides, BMSCs-Exo can also increase mitochondrial membrane potential and reduce reactive oxygen species levels in vitro. These therapeutic effects might stem from the activation of the Keap1/Nrf2 signaling pathway. CONCLUSION: BMSCs-Exo improved the tissue antioxidant capacity by regulating the keap1/Nrf2 signaling pathway. BMSCs-Exo may be a new strategy to solve the problem of random flap necrosis.

Prognosis of Pediatric Patients With Mucoepidermoid Carcinoma of the Parotid Gland.

OBJECTIVE: To summarize the prognosis of pediatric patients with mucoepidermoid carcinoma (MEC) of the parotid gland. METHODS: Pediatric patients with MEC of parotid gland who were surgically treated at the Capital Medical University School of Stomatology from 2000 to 2014 were retrospectively analyzed. Clinical characteristics, pathology reports, and operation records were reviewed and analyzed. RESULTS: In total, 33 patients with an average age of 13.2 years were enrolled. The 5-year overall survival and disease-free survival were 95.8% and 84.4%, respectively. The disease-free survival and overall survival rates were lower in the under-10 age group (75.0 versus 87.7% and 83.3% versus 100%), though no statistically significant difference was found (P = 0.279 and P = 0.075). The patients who underwent complete resection all had a good prognosis without any recurrence or death regardless of whether the cut margin was 1.0 cm, 0.5 cm, or only extracapsular. One patient experienced 3 recurrences within 18 months and eventually died of disease. CONCLUSION: Good outcomes were achieved in pediatric patients with MEC of the parotid gland. Radical resection ensured a good prognosis regardless of the extent of resection. Frequent recurrence in a short period was associated with a poor prognosis. TRIAL REGISTRATION: None.

Modified in-continuity resection is advantageous for prognosis and as a new surgical strategy for management of oral tongue cancer.

OBJECTIVE: The aim of this study was to explore the application value of modified in-continuity resection compared with traditional in-continuity resection and discontinuous resection for patients with cT2 N0 M0 oral tongue squamous cell carcinoma. STUDY DESIGN: This was a retrospective cohort study. The predictor was surgical management. The main outcome assessment parameters were the 5-year intervening regional (submandibular area and floor of mouth) recurrence rate and the 5-year disease-specific survival rate. Descriptive and bivariate statistics were computed, and the P value was .05. RESULTS: We reviewed 406 patients: 212 in the discontinuous resection group, 101 in the in-continuity resection group, and 93 in the modified in-continuity resection group. Kaplan-Meier analysis showed that modified in-continuity resection was better than discontinuous resection with regard to both 5-year intervening regional recurrence (6.3% vs 18.8%; P = .004) and 5-year disease-specific survival (88.6% vs 75.1%; P = .003). Additionally, modified in-continuity resection had a lower postoperative complication rate compared with in-continuity resection (3.8% vs 13.2%; P = .044). CONCLUSIONS: The modified in-continuity resection is valuable for application in clinical practice for cT2 N0 M0 oral tongue squamous cell carcinoma.