Permeabilized Cryopreserved Human Hepatocytes as an Exogenous Metabolic System in a Novel Metabolism-Dependent Cytotoxicity Assay for the Evaluation of Metabolic Activation and Detoxification of Drugs Associated with Drug-Induced Liver Injuries: Results with Acetaminophen, Amiodarone, Cyclophosphamide, Ketoconazole, Nefazodone, and Troglitazone