This study addressed how collective, supra-organismal colony characteristics change during growth (sociogenesis) from the founding queen to maturity and through the seasons. A total of 31 harvester ant colonies representing a full range of sizes was excavated on 4 sample dates during the year. The data were analyzed for growth-related and seasonal patterns. The subterranean nests consisted of h...

Multiple transforming growth factors (TGFs) have been isolated from the serum-free conditioned media and acid-ethanol cell extracts of nontransformed AKR-2B and chemically transformed AKR-MCA mouse cells. The TGF activity was analyzed using Bio-Gel P-60 chromatography in 1 M acetic acid and tested for colony-stimulating activity in soft agar using AKR-2B, AKR-2B (clone 84A), NRK, and AKR-MCA ce...

These experiments were designed to test whether autocrine/paracrine mechanisms are involved in the growth-promoting action of progesterone (Pg) in the N-nitrosomethylurea-induced rat mammary tumor cultured in vitro in soft agar clonogenic assay. In support of our hypothesis, we observed that conditioned media obtained from Pg-treated tumors (Pg-CM), consistently stimulated colony formation in o...

Bone marrow or blood of patients with acute myeloid leukemia was subjected to cell separation and the cells investigated for in vitro colony growth. Discontinuous albumin density gradient centrifugation and depletion of E-rosette-forming cells resulted in purified fractions of acute myeloid leukemia cells. From these fractions, growth of large leukemic colonies was obtained in the PHA-leukocyte...

The addition of human serum to colony stimulating factor (CSF) enhances the growth of granulocyte and macrophage colonies derived from C57 BL/6 mouse marrow cells. The growthenhancing effect of normal human serum was dose-dependent and observed in various colony assay systems employing conditioned medium prepared from L-cells, human peripheral blood leukocytes, C BL/6 mouse whole embryo and ser...

Several hemopoietic growth factors have now been purified, cloned, and produced in bacteria. Granulocyte colony stimulating factor and granulocyte-macrophage colony stimulating factor are already being used in clinical trials. Within 12 months two more hemopoietic growth factors, macrophage colony stimulating factor (also called colony stimulating factor 1) and interleukin 3 (also called multi-...