Liquid chromatography-tandem mass spectrometry method for determining tolvaptan and its nine metabolites in rat serum: application to a pharmacokinetic study.

Tolvaptan is a competitive vasopressin V2-receptor antagonist that inhibits water reabsorption in the renal collecting ducts. A selective and sensitive liquid chromatography-tandem mass spectrometry method for determining tolvaptan and its nine metabolites in rat serum was developed and validated. An analogue of tolvaptan was used as an internal standard.

Diverse p53 gene aberration in hepatocellular carcinoma detected by dual-color fluorescence in situ hybridization.

Background And Aim: In order to evaluate loss of the p53 gene more precisely, we performed dual-color fluorescence in situ hybridization (dual-color FISH) for chromosome 17 and p53 gene together with DNA polymorphism analysis of the p53 gene in hepatocellular carcinoma (HCC).

Methods: Dual-color FISH using probes specific for the centromere of chromosome 17 and the p53 gene was performed for 41 HCC and DNA polymorphism analysis was also performed for them.

Results: Of the 34 HCC tested by dual-color FISH, 20 had loss of at least one p53 gene (58.