PURPOSE: This study was carried out to determine the protective effects of vitamin C on the hepatotoxicity induced by radiation. MATERIALS AND METHODS: The Spraque Dawley rats were randomly divided into 3 groups; the control group, the radiation exposed group, and the radiation and vitamin C-treated group. SOD activity, catalase, malondialdehyde and liver enzymes were analyzed to assess the antioxidant effects of vitamin C. RESULTS: The increased level of malondialdehyde and the decreased catalase activity that were induced by radiation were improved after vitamin C but there was no statistical significance among three groups. The superoxide dismutase activity of the liver was increased by vitamin C, but there were no statistically significant differences between the vitamin C-treated group and the non vitamin C-treated group. The level of liver enzymes in sera such as glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, lactate dehyrogenase and alkaline phosphatase were remarkably elevated by radiation. The levels of those enzymes were decreased in the vitamin C-treated group and statistical significance was noted for the GPT level (p<0.01). On the lectromicrographic findings, the hepatic cell destruction was considerably decreased in the vitamin C-treated group. CONCLUSION: Vitamin C is thought to be an effective antioxidant against the hepatotoxicity induced by radiation.
Alanine Transaminase ; Alkaline Phosphatase ; Animals ; Antioxidants ; Ascorbic Acid* ; Aspartate Aminotransferases ; Catalase ; Hepatocytes ; Lactic Acid ; Liver ; Malondialdehyde ; Rats ; Superoxide Dismutase ; Vitamins*

PURPOSE: Selective inhibition of multiple molecular targets may improve the antitumor activity of radiation. Two specific inhibitors of selective cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) were combined with radiation on the HeLa cell line. To investigate cooperative mechanism with selective COX-2 inhibitor and EGFR blocker, in vitro experiments were done. MATERIASL AND METHODS: Antitumor effect was obtained by growth inhibition and apoptosis analysis by annexin V-Flous method. Radiation modulation effects were determined by the clonogenic cell survival assay. Surviving fractions at 2 Gy (SF2) and dose enhancement ratio at a surviving fraction of 0.25 were evaluated. To investigate the mechanism of the modulation of radiosensitivity, the cell cycle analyses were done by flow cytometry. The bcl-2 and bax expressions were analyzed by western blot. RESULTS: A cooperative effect were observed on the apoptosis of the HeLa cell line when combination of the two drugs, AG 1478 and NS 398 with radiation at the lowest doses, apoptosis of 22.70% compare with combination of the one drug with radiation, apoptosis of 8.49 %. In cell cycle analysis, accumulation of cell on G0/G1 phase and decrement of S phase fraction was observed from 24 hours to 72 hours after treatment with radiation, AG 1478 and NS 398. The combination of NS 398 and AG 1478 enhanced radiosensitivity in a concentration-dependent manner in HeLa cells with dose enhancement ratios of 3.00 and SF2 of 0.12 but the combination of one drug with radiation was not enhanced radiosensitivity with dose enhancement ratios of 1.12 and SF2 of 0.68 (p=0.005). The expression levels of bcl-2 and bax were reduced when combined with AG 1478 and NS 398. CONCLUSION: Our results indicate that the selective COX-2 inhibitor and EGFR blocker combined with radiation have potential additive or cooperative effects on radiation treatment and may act through various mechanisms including direct inhibition of tumor cell proliferation, suppression of tumor cell cycle progression and inhibition of anti-apoptotic proteins.
Apoptosis ; Apoptosis Regulatory Proteins ; Blotting, Western ; Cell Cycle ; Cell Proliferation ; Cell Survival ; Cyclooxygenase 2 ; Epidermal Growth Factor* ; Flow Cytometry ; HeLa Cells* ; Humans ; Radiation Tolerance* ; Receptor, Epidermal Growth Factor* ; S Phase

PURPOSE: Concurrent chemoradiation (CRT) with 3-weekly doses of cisplatin is a standard treatment for loco-regionally advanced head and neck squamous cell carcinoma (HNSCC). However, treatment with 3-weekly doses of cisplatin is often associated with several adverse events. Therefore, we conducted this retrospective analysis to determine the efficacy and tolerance of CRT with a low weekly dose of cisplatin in stage IV HNSCC patients. MATERIALS AND METHODS: Medical records of patients who were diagnosed with stage IV HNSCC and received concurrent CRT were analyzed. All patients were treated weekly with cisplatin at 20-30 mg/m2 until radiotherapy was completed. RESULTS: A total of 35 patients were reviewed. Median follow up was 10.7 months (range, 1.7 to 90.5 months), the median radiation dose was 7,040 cGy, and the median dose of cisplatin received was 157 mg/m2. Eleven patients received docetaxel combination chemotherapy. Overall, 25 patients (71.4%) achieved complete response (CR), eight (22.9%) showed partial response. The median overall survival was 42.7 months, the 3-year survival rate was 51.2% and the 3 year disease-free survival rate was 72.8%. Overall survival was improved in patients who achieved CR relative to others (59.7 months vs. 13.4 months; p=0.008). There were significant differences in survival between patients who received docetaxel combination and cisplatin alone (51.8 months vs. 7.9 months; p=0.009). Grade 3-4 adverse events included stomatitis (82.9%), dermatitis (22.9%), infection (11.4%), dysphagia (8.6%), and neutropenia (5.7%). CONCLUSION: CRT with low dose weekly cisplatin is likely effective and tolerable, even in patients with locally advanced-stage IV HNSCC.
Carcinoma, Squamous Cell* ; Chemoradiotherapy ; Cisplatin* ; Deglutition Disorders ; Dermatitis ; Disease-Free Survival ; Drug Therapy, Combination ; Follow-Up Studies ; Head and Neck Neoplasms ; Head* ; Humans ; Medical Records ; Neck* ; Neutropenia ; Radiotherapy ; Retrospective Studies ; Stomatitis ; Survival Rate