RESUMO
Hypoxia promotes proliferation and differentiation of neural stem cells from embryonic day 12 rat brain tissue, but the concentration and time of hypoxic preconditioning are controversial. To address this, we cultured neural stem cells isolated from embryonic day 14 rat cerebral cortex in 5% and 10% oxygen in vitro. MTT assay, neurosphere number, and immunofluorescent staining found that 5% or 10% oxygen preconditioning for 72 hours improved neural stem cell viability and proliferation. With prolonged hypoxic duration (120 hours), the proportion of apoptotic cells increased. Thus, 5% oxygen preconditioning for 72 hours promotes neural stem cell proliferation and neuronal differentiation. Our findings indicate that the optimal concentration and duration of hypoxic preconditioning for promoting proliferation and differentiation of neural stem cells from the cerebral cortex are 5% oxygen for 72 hours.
RESUMO
OBJECTIVE: To explore and evaluate the application of epiglottis with sternohyoid muscle in the surgery for laryngeal cancer. METHODS: Two fifty patients with laryngeal cancer were treated by partial laryngectomy and the laryngeal defects were reconstructed by epiglottic flap and sternohyoid muscle fascia flap. The staging of tumors: T2N0M0 23 cases, T3N1M0 14 cases, T3N2M0 13 cases. All of them received post radical radiotherapy with average 60 Gy. The patients were followed up for 3 to 5 years. Thirty patients underwent neck dissection. RESULTS: The three and five years survival rates were 90% and 80% respectively. The total cases eat breath pronounced well. The decannulation rate was 96%. CONCLUSION: After partial laryngectomy in laryngeal cancer epiglottic flap and sternohyoid muscle fascia flap were performed reconstruction of laryngeal function.
