Comparative Studies on the Effect of Corynebacterium parvum on Bone-Marrow Cell Colony Formation in Vitro

Bone-marrow cells are able to proliferate in agar cultures and form distinct colonies of granulocytes or macrophages if stimulated by the colony-stimulating factor (Bradley and Metcalf, 1966; Metcalf, 1970; Pike and Robinson, 1970; Paran and Sachs, 1968). This factor is necessary for the initiation and maintenance of colonies in vitro and probably as a regulator of granulopoiesis and monocyte formation in vivo. Colony-stimulating factor (CSF) is detectable in the serum and urine of normal mice and humans and appears to be unique for the granulopoiesis and monocyte formation (Paran and Sachs, 1968; Price et al., 1973; Paran et al., 1968; Craddock et al., 1973; Landau and Sachs, 1971). It has been extensively studied, and its activity, biochemical property, and inhibition have been determined (Robinson et al., 1967; Ichikawa et al., 1967; Stanley et al.,1968; Stanley and Metcalf, 1969; Chan et al., 1971).