Comparison of hepatotoxicity and mechanisms induced by triclosan (TCS) and methyl-triclosan (MTCS) in human liver hepatocellular HepG2 cells.

Triclosan (TCS) is used as an antimicrobial agent and has been widely dispersed and detected in the environment and organisms including human samples. Methyl-triclosan (MTCS) is the predominant bacterial TCS metabolite. At present, the toxicological effects and mechanism of TCS and MTCS are still not fully understood. In this study, the cytotoxic effects of TCS and MTCS in HepG2 cells were investigated in terms of cell proliferation, comet assay, cell cycle, and apoptosis. In addition, the expressions of related proteins were detected with western blotting analysis. The results showed that TCS could significantly inhibit cell proliferation, while MTCS had no obvious effect on cell growth. Both TCS and MTCS caused oxidative injury associated with HO-1 induction and increased DNA strand breaks, which consequently initiated the damage repair process via up-regulation of DNA-PKcs. In addition, TCS blocked the HepG2 cells in S and G2/M phases of cell cycle through down-regulation of cyclin A2 and CDK; while MTCS induced cell cycle arrest at the S phase through up-regulation of cyclin A2 and CDK. Furthermore, TCS activated p53 mediated apoptosis in HepG2 cells in a caspase-independent manner, while MTCS induced apoptosis was dependent on caspase. Moreover, TCS exposure exhibited more severe toxicity in HepG2 cells as compared with MTCS exposure, indicating that the replacement of the ionizable proton in TCS by the methyl group in MTCS is correlated with the cellular toxicity and the molecular mechanism.

Mandibular distraction osteogenesis reconstructed the upper airway in a case of Melnick-Needles syndrome.

INTRODUCTION: We report a 16-year-old female with Melnick-Needles syndrome complicated with severe obstructive sleep apnea-hypoxia syndrome. CLINICAL REPORT: An overnight sleep study demonstrated that the patient had severe obstructive sleep apnea with an apnea-hypopnea index of 95/h. The lowest oxygen saturation was only 34%. The distraction osteogenesis technique was used to lengthen her mandible for the reconstruction of her upper airway. RESULT AND DISCUSSION: Postoperative panorex showed that the bilateral body of her mandible had been distracted about 16 mm singulorumly in the end of our distraction. Lateral radiograph revealed that the diameter of oral pharynx widen nearly 5 mm. The patient recovered after the upper airway reconstruction.