1. Faculty of Nursing Pediatric Clinic, "P & A Kyriakou" Children's Hospital, National and Kapodistrian University of Athens Athens Greece
2. Pediatric Research Laboratory, Faculty of Nursing National and Kapodistrian University of Athens Athens Greece
3. Stem cell Transplant Unit, "Aghia Sophia" Children's Hospital Athens Greece
4. Public Health Laboratories, Hellenic Pasteur Institute Athens Greece
5. Department of Internal Medicine, Faculty of Nursing Athens General and Oncology Hospital "Agii Anargyri", National and Kapodistrian University of Athens Athens Greece