No abstract available.

BACKGROUND: Lipemia, a significant source of analytical errors in clinical laboratory settings, should be removed prior to measuring biochemical parameters. We investigated whether lipemia in serum/plasma samples can be removed using a method that is easier and more practicable than ultracentrifugation, the current reference method. METHODS: Seven hospital laboratories in Spain participated in this study. We first compared the effectiveness of ultracentrifugation (108,200×g) and high-speed centrifugation (10,000×g for 15 minutes) in removing lipemia. Second, we compared high-speed centrifugation with two liquid-liquid extraction methods—LipoClear (StatSpin, Norwood, USA), and 1,1,2-trichlorotrifluoroethane (Merck, Darmstadt, Germany). We assessed 14 biochemical parameters: serum/plasma concentrations of sodium ion, potassium ion, chloride ion, glucose, total protein, albumin, creatinine, urea, alkaline phosphatase, gamma-glutamyl transferase, alanine aminotransferase, aspartate-aminotransferase, calcium, and bilirubin. We analyzed whether the differences between lipemia removal methods exceeded the limit for clinically significant interference (LCSI). RESULTS: When ultracentrifugation and high-speed centrifugation were compared, no parameter had a difference that exceeded the LCSI. When high-speed centrifugation was compared with the two liquid-liquid extraction methods, we found differences exceeding the LCSI in protein, calcium, and aspartate aminotransferase in the comparison with 1,1,2-trichlorotrifluoroethane, and in protein, albumin, and calcium in the comparison with LipoClear. Differences in other parameters did not exceed the LCSI. CONCLUSIONS: High-speed centrifugation (10,000×g for 15 minutes) can be used instead of ultracentrifugation to remove lipemia in serum/plasma samples. LipoClear and 1,1,2-trichlorotrifluoroethane are unsuitable as they interfere with the measurement of certain parameters.
Alanine Transaminase ; Alkaline Phosphatase ; Aspartate Aminotransferases ; Bilirubin ; Calcium ; Centrifugation ; Creatinine ; Glucose ; Hyperlipidemias* ; Laboratories, Hospital ; Liquid-Liquid Extraction ; Methods ; Potassium ; Sodium ; Spain ; Transferases ; Ultracentrifugation ; Urea

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