Objective:To investigate the methylation of CpG island of metallothionein-3 (MT-3) gene in esophageal cancer tissues and normal tissues in middle and south area of Hebei Province and Chaoshan area of Guangdong Province and compared the results with those in low risk area of esophageal cancer. Methods:The blood samples from 10 normal volunteers, 10 embryonic esophageal tissues, 20 esophageal mucosa tissues from normal subjects in low risk area as well as 30 fresh surgical specimens of esophageal cancer and 30 normal marginal tissues in the high risk middle-south Hebei Province and Chaoshan area were collected. Methylation-specific polymerase chain reaction (MSP) was used to detect the methylation status of the CpG island of MT-3 gene in these samples. Its relationship with clinicopatho-logical features was analyzed. Results:There were 20 (33.3%) cases with MT-3 methylation in the marginal tissues of esophageal cancer from high-risk area, which was higher than that in the normal mucosa from low-risk area (P=0.013). And there were 49 (81.7%) cases with MT-3 methylation in esophageal cancer tissues, which was higher than that in normal marginal tissues (P<0.001). But there was no significant difference in the methylation degree between middle-south of Hebei Province and Chaoshan area (P=0.739). Conclusion:MT-3 methylation widely exists in esophageal mucosa and carcinoma tissues. Acquired stimulus may be the main cause of these methylations.

In the HPLC analysis of bendamustine hydrochloride, two related substances(IMP01 and IMP02)were detected. These two related substances were identified by LC-MS/MS and their structural confirmation was unambiguously carried out by synthesis followed by characterization using Q-TOF/MS and NMR. Based on the spectral data, related substances IMP01 and IMP02 were characterized as 4-(1-methyl-5-morpholino-1H-benzo［d］imidazol-2-yl)butyric acid hydrochloride and 4-{1-methyl-5-［(2-chloroethyl)(2-hydroxyethyl)amino］-1H-benzo［d］imidazol-2-yl)} butyric acid hydrochloride, respectively. Bendamustine hydrochloride and its related substances were separated under the established LC-MS condition. HPLC is a useful method for the determination of the related substances in bendamustine hydrochloride. Results obtained are valuable for its manufacturing process and quality control.