In this study, 1-norm, 2-norm, and quantile normalization techniques were evaluated to compare the effects of three different normalization methods on liquid chromatography-mass spectrometry (LC-MS)-based metabolomics data.
Experimental
Study designThis randomized, single-blind, two-period, two-way crossover study with a 1-week washout period was conducted at the Clinical Trial Center of the Kyungpook National University Hospital, Daegu, Republic of Korea (Fig. 1). A total of eight subjects were randomly assigned to one of two treatment sequences: (1) 200 mg of cyclosporine (high dose) in the first study period, followed by 2 mg of cyclosporine (low dose) in the second study period, or (2) 2 mg cyclosporine (low dose) in the first study period, followed by 200 mg cyclosporine (high dose) in the second study period. In each period, all subjects were hospitalized 24 h before and 24 h after drug administration (Fig. 1). Pre-dose and post-dose urine samples for metabolomic profiling were collected over the 24-h period before and after oral administration of cyclosporine.