[Melatonin in in vitro apoptosis of H22 hepatocarcinoma cells].

OBJECTIVE: To study the effect of melatonin (MLT) in in vitro apoptosis of hepatocarcinoma cells and its mechanism. METHODS: The apoptotic cells, bcl-2 and bax were detected through immunocytochemical method (ICC) and Tolt-mediated x-duTP nick end labeling (TUNEL). Computer image analysis system was used to quantify the expression of bcl-2 and bax by detecting the absorbance value of positive products. Apoptosis index (AI) was used to quantify the number of apoptotic cells. RESULTS: In vitro, AI increase was both concentration- and time-dependent through TUNEL. During the same duration, AI of medium dose group was higher than that of low dose and control group (P < 0.05); AI of high dose, medium dose and 5-Fu group were higher than those of low dose and control group (P < 0.01), however, there was no significant difference between the low dose and control group (P > 0.05). At the same dose, in high dose, medium dose and 5-Fu group, the change of AI showed significant difference from 24 to 36 hours (P < 0.05). The expression of bcl-2 was down-regulated as the MLT increased, and there was significant difference between the low dose and control group (P < 0.01). But, the expression of bax was up-regulated as the dose of MLT increased, showing significant difference between the high dose and control groups (P < 0.01). As time went on, the expression of bcl-2 was decreased and in every group, with the change in absorbance value of bcl-2 significantly different from 24 to 36 hours (P < 0.05), whereas that of bax remained almost unchanged. The ratio of bax/bcl-2 was increased with the increase in the concentration of MLT. CONCLUSION: Melatonin may induce apoptosis in the hepatocarcinoma cells which is concentration- and time-dependent, in which bcl-2 and bax are involved.

Endoscopic therapy of colonic liver flexure mucocele.

Colorectal mucoceles usually arise in the appendix, and colonic disease is very rare. We report the first case of a mucocele of the colonic liver flexure that was treated successfully with endoscopy. A 36-year-old man was admitted to our hospital because of abdominal distension persisting for 3 days. Colonoscopic examination revealed a round polyp in the hepatic flexure, and we performed hot snare polypectomy with argon plasma coagulation. Histologically, the polypectomy specimen was confirmed to be a mucocele, with no neoplastic changes. Follow-up examinations at 6 and 12 months showed no evidence of recurrence.