To investigate the effect of hyperbaric oxygenation on superoxide dismutase activity, neonatal rats (7-10 days old) and adult rats (approximately 100 days old) were continuously exposed to hyperbaric oxygen environment of 2.4ATA for 8 hours and their superoxide dismutase activity were measured. Neonatal rats, all survived through exposure, showed significant increases in the pulmonary superoxide dismutase activity at immediately and 24 hours after exposure. Adult rats, whose 8 hour survival rates were 14 %, did not show any significant increase in the activity of pulmonary superoxide dismutase as compared to the control adult rats. These findings are indicating that increased tolerance to oxygen toxicity in neonatal animals during exposure may be attributed to the increase in activity of superoxide dismutase in neonatal rats.
Adult* ; Animals ; Animals, Newborn ; Humans ; Hyperbaric Oxygenation* ; Oxygen ; Rats* ; Superoxide Dismutase* ; Superoxides* ; Survival Rate

PURPOSE: The purpose of this study is to analyze treatment outcome of radiotherapy (RT) in patients with stage III-IV tonsil cancer managed by surgery followed by postoperative RT (SRT) and definitive chemoradiotherapy (CRT), and to thereby evaluate the most feasible treatment modality. MATERIALS AND METHODS: Of 124 patients, 67 underwent CRT, and 57 underwent SRT. We compared survival and complication rates in both groups. RESULTS: The median follow-up time was 57 months (range, 19 to 255 months) for surviving patients. At five years, locoregional progression-free survival (LRPFS) and overall survival (OS) were 88% and 80%, respectively. No significant difference in LRPFS (p=0.491) and OS (p=0.177) was observed between CRT and SRT. In multivariate analysis, old age and higher T stage showed a significant association with poor LRPFS, PFS, and OS; higher N stage showed an association with poor PFS and a trend of poor LRPFS, while no association with OS was observed; treatment modality (CRT and SRT) showed no association with LRFPS, PFS, and OS. Grade 3 or higher mucositis was observed in 12 patients (21%) in the SRT group, and 25 patients (37%) in the CRT group. CONCLUSION: Definitive CRT and SRT have similar treatment outcomes for patients with stage III-IV tonsil cancer. Although acute complication rate appears to be higher in the CRT group, it should be noted that not all data on complications were included in this retrospective study. To determine the most feasible treatment modality, not only mucositis and xerostomia, but also emotional aspect and quality of life, should be considered.
Chemoradiotherapy ; Disease-Free Survival ; Follow-Up Studies ; Humans ; Mucositis ; Multivariate Analysis ; Palatine Tonsil ; Quality of Life ; Radiotherapy, Intensity-Modulated ; Retrospective Studies ; Tonsillar Neoplasms ; Treatment Outcome ; Xerostomia