Objective The present paper makes attempt to study the enrichment features of mercury in freshwater fishes and to evaluate the mercury contamination in environment with the fishes.Methods The fish samples of silver carp,common carp,johnny carp,shorthead catfish and catfish were collected from Songhua River and Heilongjiang River.The content of mercury in freshwater fishes,water and sediment was determined,the biological characteristic of mercury contamination in aquatic animal and the applicability of mercury contamination in aquatic amimal and its estimation were analyzed in Sep.,2007.Results The levels of mercury in river water and sediment were 0.053 ?g/L and 0.27 mg/kg for samples collected from Jiamusi section of Songhua River,and 0.034 ?g/L and 0.16 mg/kg for samples collected from Fuyuan section of Heilongjiang River.The concentrations of total mercury in the muscles of Songhua River’s silver carp,common carp,johnny carp,shorthead catfish and catfish was(0.070 ? 0.036),(0.120?0.071),(0.113?0.067),(0.152?0.107) and(0.196?0.095) mg/kg respectively.The concentrations of total mercury in the muscles of Heilongjiang River ’s silver carp,common carp,johnny carp,shorthead catfish and catfish was(0.042 ? 0.034),(0.103?0.077),(0.095?0.072),(0.157?0.118),(0.174?0.101) mg/kg respectively.The mercury content in fish in the same water environment was significantly positive correlated with its weight(P

The discovery of induced pluripotent stem cells(iPSCs) is a promising advancement in the field of regenerative medicine. Previous studies have indicated that the teratoma-forming propensity of iPSCs is variable; however, the relationship between tumorigenic potential and genomic instability in human iPSCs (HiPSCs) remains to be fully elucidated. Here, we evaluated the malignant potential of HiPSCs by using both colony formation assays and tumorigenicity tests. We demonstrated that HiPSCs formed tumorigenic colonies when grown in cancer cell culture medium and produced malignancies in immunodeficient mice. Furthermore, we analyzed genomic instability in HiPSCs using whole-genome copy number variation analysis and determined that the extent of genomic instability was related with both the cells' propensity to form colonies and their potential for tumorigenesis. These findings indicate a risk for potential malignancy of HiPSCs derived from genomic instability and suggest that quality control tests, including comprehensive tumorigenicity assays and genomic integrity validation, should be rigorously executed before the clinical application of HiPSCs. In addition, HiPSCs should be generated through the use of combined factors or other approaches that decrease the likelihood of genomic instability.
Animals ; Carcinogenesis ; Cells, Cultured ; DNA Copy Number Variations ; Genomic Instability ; Humans ; Induced Pluripotent Stem Cells ; cytology ; metabolism ; transplantation ; Mice ; Mice, SCID ; NIH 3T3 Cells ; Octamer Transcription Factor-3 ; metabolism ; Teratocarcinoma ; etiology ; Teratoma ; etiology ; Tumor Stem Cell Assay