4. Statistical analysis - Categorical data are presented as absolute values and percentages, whereas continuous data are summarized as mean and Standard Deviation. Statistical analysis was performed using t-test for paired or unpaired samples. Time courses of measurements of liver function parameters were analyzed by repeated-measures ANOVA. The analyses were performed using the SPSS 15.0 statistical package (SPSS Inc., Chicago, IL, USA). All statistical analyses were based on two-tailed hypothesis tests with a significance level of p< 0.05.