Affiliation: | (1) State Institute for Immune Preparates and Nutrition Media, DDR-112 Berlin, German Democratic Republic;(2) Institute of Pathology, Friedrich-Schiller-University Jena, DDR-69 Jena, German Democratic Republic;(3) Staatliches Institut für Immunpräparate und Nährmedien, Klement-Gottwald-Allee 315, DDR-112, Berlin |