Poetsch, Micaela http://orcid.org/0000-0003-1364-6487
Pfeifer, Manuel
Konrad, Helen
Bajanowski, Thomas
Helmus, Janine
Article History
Received: 9 October 2017
Accepted: 13 November 2017
First Online: 18 November 2017
Compliance with ethical standards
: All samples were obtained after informed consent and with approval of the Medical Ethics Committee at the University of Duisburg-Essen in accordance with the Declaration of Helsinki and national laws.
: The authors declare that they have no conflict of interest.