Statistical Analysis
All data were entered into Excel spreadsheets and analyzed using Statistica MAC (Statsoft, Tulsa, OK) and Statview (SAS Institute, Inc., Cary, NC). Statistical analysis was performed using the Student t test for paired and unpaired values, the Mann-Whitney U test, the Fisher exact test, the chi-square test, and ANOVA. For a post hoc test the Bonferroni/Dunn test was used. P values < 0.05 were considered significant. All continuous variables are reported as mean ± SEM. Survival curves were plotted in the form of Kaplan-Meier, and 95% confidence intervals (CI) were calculated using Statview (SAS Institute, Inc., Cary, NC).