摘要:

AbstractThe granulocyte colony‐stimulating factor (G‐CSF) belongs to a family of hemopoietic growth factors regulating the production of granulocytes and macrophages. Murine G‐CSF stimulates the proliferation and differentiation of precursors of neutrophilic granulocytes and is also able to stimulate the functional activities of mature neutrophils. Among the hemopoietic growth factors, G‐CSF has an outstanding capacity to induce terminal differentiation and suppression of self‐renewal in myeloid leukemic cells. Murine and human G‐CSF's show complete biological cross‐reactivity across species and bind equally well to G‐CSF receptors of either species. Specific receptors for G‐CSF exist on all normal neutrophilic cells and have not been lost in the generation of primary human myeloid leukemias. This data indicates that G‐CSF may be a useful reagent in the treatment of myeloid leukemia, in hemopoietic regeneration and in increasing resistance

ISSN:0737-1454    

DOI:10.1002/stem.5530050102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractWe examined the effects of recombinant human tumor necrosis factor (rhTNF) on normal human and murine granulocyte‐macrophage (CFU‐gm) and erythroid (CFU‐e, BFU‐e) progenitor cells. We suppressed in vitro colony formation by human marrow CFU‐gm, CFU‐e and BFU‐e or peripheral blood BFU‐e by adding rhTNF to the culture in a dose‐related manner. A half‐maximal inhibition was observed with 1–10 ng/ml. Leukemic cell line K562 cells were found to be sensitive to rhTNF in the clonogenic colony assay. However, the clonal growth of murine marrow CFU‐e and BFU‐e colonies was less than 50% inhibited and CFU‐gm growth was unaffected even at a concentration of 1,000 ng/ml. We observed slight to moderate inhibition after 24 h pulse exposure of both human and murine‐committed progenitors to rhTNF prior to the culture. Intravenous injection of 1 mg/kg of rhTNF caused a marked decrease in marrow erythroid progenitors and consequently caused anemia in the mice. Our data indicate that rhTNF has a suppressive effect on normal human and murine hemopoietic colony formation in vitro and

ISSN:0737-1454    

DOI:10.1002/stem.5530050103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractProliferation and differentiation are inversely related in many cell culture systems. The study of inducible systems is facilitated by optimal growth conditions in order that whatever differentiation is observed may be attributed to a specific effect of the inducer, rather than to a nonspecific effect of adverse growth conditions. To investigate the role of CO2supply in an inducible system, the K562 human leukemia cell line inducible for hemoglobin synthesis was studied at 10%, 5% and 1.5% CO2concentrations. The lower the CO2concentration, the higher the percentage of benzidine‐positive cells but the slower the growth rate. This increase in benzidine positivity reflected hemoglobin synthesis as indicated by incorporation of3H‐leucine into globin chains. If, in addition to reducing CO2concentration, the complete medium was replaced by a bicarbonate‐free medium, the percentage of benzidine‐positive cells was further increased and growth further slowed. However, if endogenously produced CO2was retained by sealing the culture vessel, these effects were mitigated. Since addition of ribosides blocked these effects, the mechanism for these effects appears to be inhibition of riboside biosynthesis due to the depletion of CO2as a substrate. The implication of this work is that, for reproducibility in studies of inducible systems in which reduction of proliferation may itself increase the probability of differentiation, the CO2tension, the bicarbonate concentration in the medium and the rate of egress of endogenously produced CO2must be kept c

ISSN:0737-1454    

DOI:10.1002/stem.5530050104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractWe examined alkaline phosphatase (ALPase)‐positive reticular cells from chicken bone marrow in vitro in relation to other varieties of adherent cells.ALPase activity was found in both reticular and adipose cells which formed epithelioid cell colonies and were negative for fibronectin. We observed transition between two cell types. ALPase‐negative macrophages as small round cells in culture revealed positive fibronectin and transformed into ALPase‐negative spindle cells in long‐term culture. Thus, we suggest two cell lineages, each with distinct cell characte

ISSN:0737-1454    

DOI:10.1002/stem.5530050105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractIn order to analyze and define potentially better growth conditions for colonic stem cell proliferation, we chose four established human colorectal cancer cell lines that differed in biologic cell properties. We studied variables of standard cloning conditions including culture medium, serum supplement, solidifying agent, addition of specific growth factors and use of capillaries as an alternative culture vessel. While modulation of serum concentration as well as use of various standard formulations of culture base media did not result in a reproducible increase of plating efficiencies (PEs), a significant increase in colony formation (when compared to the conventional assay procedure) was achieved; 1) by use of 0.3% agarose or boiled agar as semisolid matrix and 2) by culturing of cells in enriched ‘GMF medium’. Specific growth factors, such as EGF or glucagon resulted in “occasionally better” in vitro growth. This suggests a retention of the ability of cells in culture to respond to physiologic regulators of growth. To verify and extend these initial results obtained with continuous cell lines, growth enhancing modifications of the original cloning technique were subsequently applied to in vitro growth of 15 human colorectal cancer specimens obtained directly from patients. Specimens that grew 30 or more colonies under standard plating conditions displayed a more than two‐fold increase in PEs which was reproducible for the two specific variables mentioned above, but the overall success rate of the assay could not be improved. In addition to the possibility that several deficient basic requirements for achieving optimal environmental conditions for colonic stem cell growth have not been defined, we believe a major reason for failing to improve the number of drugassayable specimens is related to an inherent interneoplastic diversity in terms of growth requirements of human colorectal mal

ISSN:0737-1454    

DOI:10.1002/stem.5530050106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

ISSN:0737-1454    

DOI:10.1002/stem.5530050107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

ISSN:0737-1454    

DOI:10.1002/stem.5530050101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY