[Mutant Rad50 enhances killing effects of radiation on nasopharyngeal carcinoma cell line CNE1].

Objective: To investigate the killing effects of radiation and mutant Rad50 transfection on human nasopharyngeal carcinoma cell line CNE1. Methods: The experimental groups included: control group, Ad-Rad50-GFP group, Ad-EGFP group, irradiation group, Ad-Rad50-GFP combined with irradiation group, and Ad-EGFP combined with irradiation group. CNE1 cells were transfected with recombinant adenoviral vector Ad-Rad50-GFP carrying mutant Rad50 gene. The expressions of Mre11, Rad50, Nbs1, and relevant constituents composing MRN complex were detected by Western Blot. Neutral comet assay was used to detect the effect of mutant Rad50 on restoration process of DNA damage. Cell growth curve was used to evaluate the growth inhibition of CNE1 by mutant Rad50 and radiation. Results: Expressions of Mre11, Rad50, and Nbs1 in cells of Ad-Rad50-GFP group were less significantly than those in control group when irradiation was completed (0.48 vs 0.62, 0.42 vs 0.5, and 0.53 vs 0.69, respectively, P<0.05) and 24 hours after irradiation (0.41 vs 0.69, 0.46 vs 0.58, and 0.34 vs 0.78, respectively, P<0.05). The mean tail moment (MTM) in Ad-Rad50-GFP plus irradiation group was higher than that in irradiation group when irradiation was completed (16.06 vs 14.8, P<0.05), 24 hours after irradiation (58.23 vs 15.89, P<0.05) and 48 hours after irradiation: (45.12 vs 11.42, P<0.05). Seven days after irradiation, the cells in Ad-Rad50-GFP plus irradiation group was less than those in control group or irradiation group (both P<0.05). Conclusion: Mutant Rad50 enhances killing effects of radiation on nasopharyngeal carcinoma cell line CNE1.

[Effect of different preparation crafts on the content of baicalin in shuanghuanglian (SHL) injection].

The content of baicalin is stable when baicalin is added quantitatively in preparation. The time of extraction of the effective components of SHL with alcohol and the concentration of alcohol have little effect on the content of baicalin. The components can be extracted once, and the content of alcohol is preferably 85%. The pH level has greater influence on the content of baicalin, and should be controlled between 7.0 to 8.0. 0.2% activated carbon is suitable in preparation.

Feasibility study of combining metronidazole with chemotherapy.

Metronidazole, 1.5 g/sq m, was administered p.o. to patients with advanced malignancies 12 hr and 1 hr before and 6 hr and 24 hr after each of adriamycin, BCNU, and mitomycin-C. Doses of adriamycin varied from 50 to 90 mg/sq m. At an adriamycin dose of 75 mg/sq m, the median granulocyte nadir was 900/microliters and the median platelet nadir was 240,000/microliters. No enhancement of stomatitis or cardiotoxicity was noted at the doses studied. Doses of BCNU varied from 145 to 265 mg/sq m. At a BCNU dose of 240 mg/sq m, the median granulocyte nadir was 2600/microliters and the median platelet nadir was 102,000/microliters. Two patients developed hypotension that may have been due to a metronidazole-alcohol interaction. Doses of mitomycin-C varied from 10 to 20 mg/sq m. At a mitomycin-C dose of 20 mg/sq m, the median granulocyte nadir was 1300/microliters and the median platelet nadir was 81,000/microliters. Four of 40 patients developed pulmonary toxicity and one developed renal toxicity. Of 11 evaluable patients treated on the adriamycin regimen, 4 responded and 5 stabilized. With BCNU, 7 of 17 responded and 2 stabilized. With mitomycin-C, 2 of 32 responded and 12 stabilized. Overall, 4 of 8 patients with squamous cell carcinoma or adenocarcinoma of the lung attained partial remissions and one had a minor response. Using this metronidazole dose schedule, phase II studies are being conducted with adriamycin, 75 mg/sq m, in squamous cell and adenocarcinomas of the head and neck; with BCNU, 240 mg/sq m, in glioblastomas and squamous cell and adenocarcinoma of the lung; and with mitomycin-C, 20 mg/sq m, in adenocarcinomas of the breast and colon.