Potential conflict of interest
Disclosure forms provided by the authors are available with the full text of this article at www.informahealthcare.com/lal.
This work was supported in part by research project of The Ministry of Education, Youth and Sports: MSM0021622434; IGA grants of The Ministry of Health: NT12130, NT12215, NT13492, NT13190; grant of The Czech Science Foundation GAP304/10/1395 and MUNI/A/0784/2011.