In this article, we present evidence that sialic acid-containing surface components play a role in the regulation of erythropoiesis. A 1-hr exposure of mouse bone marrow cells to high concentrations of neuraminidase reduced erythroid colony formation. Coculture of 10(6) untreated thymocytes with neuraminidase-treated bone marrow cells restored erythroid colony growth. Neuraminidase-treated thym...

Background: Siphonophores (Hydrozoa) have unparalleled colony-level complexity, precision of colony organization, and functional specialization between zooids (i.e., the units that make up colonies). Previous work has shown that, unlike other colonial animals, most growth in siphonophores is restricted to one or two well-defined growth zones that are the sites of both elongation and zooid buddi...

U937 cells, an established monoblast or early monocyte cell line, were assessed as a model in vitro for the regulation of cell growth at the single cell level. Colony formation by 500 U937 cells, preinduced to a state of responsiveness to lactoferrin (LF) by incubation with human y Interferon was suppressed by LF. LF-suppressed colony formation was restored by partially purified growth activity...

In vitro colony-forming ability of untreated acute nonlymphocytic leukemia (ANLL) cells determined by the CFU-C assay with and without PHA presensitization, and also human Ia-like antigen of their surfaces were investigated. In vitro colony-forming ability of 32 ANLLs was classified into four types: (A) no colony growth: 16, (B) PHA-dependent colony growth: 9, (C) colony-stimulating factor (CSF...

Human small cell lung cancers (SCLC) produce and secrete the regulatory peptide bombesin (BN) or its mammalian counterpart gastrin-releasing peptide (GRP). In addition, several SCLC tumor lines have been shown to express high affinity receptors for BN/GRP. On the basis of these findings, we investigated the effect of exogenously added BN and GRP on the soft agarose colony growth of a panel of h...

Human small cell lung cancers (SCLC) produce and secrete the regulatory peptide bombesin (BN) or its mammalian counterpart gastrinreleasing peptide (GRP). In addition, several SCLC tumor lines have been shown to express high affinity receptors for BN/GRP. On the basis of these findings, we investigated the effect of exogenously added BN and GRP on the soft agarose colony growth of a panel of hu...

the objective of this study was to evaluate the effect of the sto feeder layer on prepubertal rhode island red rooster sscs culture and proliferation in vitro. testis cells from 30 prepubertal rhode island red chicken (4-8 weeks of age), were individually separated and cultivated in the presence of  bfgf and lif growth factors on four well plates with two treatments and three replicats and five...

Human small cell lung cancers (SCLC) produce and secrete the regulatory peptide bombesin (BN) or its mammalian counterpart gastrinreleasing peptide (GRP). In addition, several SCLC tumor lines have been shown to express high affinity receptors for BN/GRP. On the basis of these findings, we investigated the effect of exogenously added BN and GRP on the soft agarose colony growth of a panel of hu...

The effects of human recombinant granulocyte/macrophage colony-stimulating factor (GM-CSF) and human native purified granulocyte colony-stimulating factor (G-CSF) on the growth of clonogenic leukemic blast cells from eight Japanese patients with acute myeloblastic leukemia were studied, using an in vitro leukemic blast colony assay. The results showed that GM-CSF stimulated leukemic blast colon...

Sera from patients with bone marrow megakaryocyte aplasia are a rich source of megakaryocyte colony-stimulating activity (Meg-CSA). Other biologic materials exhibiting Meg-CSA include phytohemagglutinin-stimulated human lymphocyte-conditioned medium (PHA-LCM), recombinant interleukin-3 (IL-3), and recombinant granulocyte macrophage colony-stimulating factor (GM-CSF). Neutralizing antisera to bo...