[1] First Department of Medicine,
[2] Christian Albrecht University,undefined
[3] Schittenhelmstrasse 12,undefined
[4] D-24105 Kiel,undefined
[5] Germany e-mail: s.schreiber@mucosa.de,undefined
[6] Tel.: +49-30-5971279,undefined
[7] Fax: +49-30-5971842,undefined