human placenta-conditioned medium , a partially purified preparation of colony-stimulating factor , rapidly and significantly increased the intracellular putrescine concentration of light-density , non-adherent , t-lymphocyte-depleted human marrow cells , inhibition of polyamine biosynthesis with alpha-difluoromethylornithine , a catalytic , irreversible inhibitor or ornithine decarboxylase , resulted in an accumulation of blasts , promyelocytes , and myelocytes with a concomitant decrease in metamyelocytes and polymorphonuclear granulocytes , suggesting a granulopoietic differentiation block .
C0002260
alpha-difluoromethylornithine
C0029282
ornithine