THE CONTENT OF THE MAIN ANGIOGENESIS ACTIVATOR - GROWTH FACTOR OF ENDOTHELIAL VESSELS - IN BLOOD SERUM OF HEALTHY PERSONS AND OF PATIENTS WITH OSTEOSARCOMA Article Kushlinsky N.E., Solovyov Yu.N., Borisov D.A., Kuznetsova O.M., Berezov Klinichescheskaya Laboratornaya Diagnostika. Izdatel'stvo Meditsina. 2004. P. 9a-10