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  • 1
    Digitale Medien
    Digitale Medien
    [s.l.] : Nature Publishing Group
    Nature 259 (1976), S. 127-129 
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] Although induction of macrophage and granulocyte colonies does not seem to require addition of a foreign antigen, normal lymphocytes require antigenic stimulation for differentiation in mass culture in liquid medium7'8. This suggested that colony formation with normal lymphocytes might be induced ...
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 0021-9541
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Sera from different strains of mice injected with endotoxin induced clones (D+) from a cultured line of myeloid leukemic cells to undergo normal differentiation to mature granulocytes and macrophages. Other clones (D-) derived from the same cell line were not inducible by these sera to undergo normal cell differentiation. Sera from the same strains of mice that had not been injected with endotoxin, increased the cloning efficiency of D+ and D - clones but did not induce differentiation. Endotoxin serum induced differentiation in D+ cells at dilutions up to 1:64, but increased the cloning efficiency of these cells at dilutions up to 1:2048. The end point of the dilution of endotoxin serum that induced differentiation in D+ cells, was also the end point that induced the formation of colonies with differentiation from normal bone marrow cells. The results indicate that serum from endotoxin treated animals can serve as a good in vivo source to induce normal differentiation in D+ myeloid leukemic cells; that the progeny of a single leukemic cell was induced to undergo differentiation to both macrophages and granulocytes; that endotoxin serum contained two activities, one that increased cloning efficiency and the other that induced cell differentiation; and that the same material in endotoxin serum induced cell differentiation in normal and leukemic cells.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 89 (1976), S. 259-266 
    ISSN: 0021-9541
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Normal hematopoietic cells require the presence of a protein (MGI) in the appropriate conditioned medium (CM) for cell viability and growth and for differentiation to mature macrophages and granulocytes. Clones of myeloid leukemic cells have been established in culture (D+ clones) which require CM with this protein for differentiation, but not for cell viability and growth. It has been shown that these leukemic cells can be induced by CM to again require, like normal cells, the presence of CM for cell viability and growth. Induction of this requirement, which will be referred to as RVG, occurred before the D+ cells differentiated to mature granulocytes. Clones of myeloid leukemic cells (D- clones) that could not be induced to differentiate to mature cells, did not show the induction of RVG. The steroid hormones prednisolone and dexamethasone can induce some, but not all the changes associated with differentiation of D+ cells. Incubation with these steroids did not result in the induction of a requirement for these steroids for cell growth and viability. Studies with CM from different sources have shown, that all batches that induced RVG also induced differentiation of D+ cells and that both activities were inhibited after treating the CM with trypsin. It is suggested that the same protein (MGI) may be involved in both activities. Incubation of D+ cells with CM resulted in an increase in agglutinability by concanavalin A and this increase was maintained even in the absence of CM. This suggests, that the induction of RVG in D+ myeloid leukemic cells is associated with a change in the cell surface membrane.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 113 (1982), S. 152-158 
    ISSN: 0021-9541
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: More than 80% of cells from a human promyelocytic leukemic cell line (HL-60) possess the capacity for self-renewal as evidenced by their ability to form large primary colonies in semisolid medium and the presence within these colonies of cells capable of subsequent colony formation. Colony development is independent of the normal regulator-the myeloid colony stimulating factor. The observed autostimulation suggests the production of specific growth promoters by the cells. Differentiation either to mature granulocytes or macrophages, induced by various agents, was associated with reduced cloning potential. Nevertheless, colonies containing differentiated cells could be developed either by cloning cells in the presence of suboptimal concentrations of inducer or by adding inducers over colonies developed in its absence. Upon differentiation, there was a morphological change from compact to diffused colony morphology due to cell mobility in the semisolid medium. Even at suboptimal concentrations of inducer more than 95% of the colonies became diffused, indicating clonaI homogeneity of the population with respect to differentiation capacity. The loss of self-renewal was found to be one of the early properties which changed following the initiation of differentiation. The loss preceded not only the overt expression of maturation-specific functions but also cellular commitment to terminal differentiation; shorter contact with the inducer was required to cause loss of self-renewal than to induce an irreversible transition to differentiation. This resulted in cells that lost their self-renewal potential without being able to complete their program of differentiation.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 87 (1976), S. 167-177 
    ISSN: 0021-9541
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Glucose utilization, energy metabolism and associated membrane changes, have been studied in D+ myeloid leukemic cells that can be induced to undergo cell differentiation to mature granulocytes by incubation with the appropriate conditioned medium (CM) and in D- myeloid leukemic cells that cannot be induced to differentiate to mature cells. Before incubation with CM, glycolysis and the glycolytic production of ATP were lower and the activity of the pentose cycle was higher in D+ than in D- cells. ATP depletion induced a higher degree of agglutination by concanavalin A in D- than in D+ cells, indicating a difference in their surface membrane. There were no detectable differences in the transport of glucose and the synthesis of sterols and fatty acids. After incubation with CM, the D+ cells, like normal granulocytes, showed a higher glycolysis, produced their ATP more through glycolysis than oxidative phosphorylation, became less dependent on the exogenous supply of glucose and oxygen and had a lower rate of sterol and fatty acid synthesis. The differentiating D+ cells also showed a change in their surface membrane resulting in an increased agglutinability without a change in ATP content and a stimulation of the pentose cycle by concanavalin A. These properties, which were not acquired by D- cells, were found before most of the D+ cells had differentiated to mature granulocytes. The data indicate, that the block in the ability of the D- cells to differentiate and the acquisition of the metabolic properties of normal granulocytes by differentiating D+ cells, were associated with differences in the organization of the cell surface membrane.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 86 (1975), S. 221-230 
    ISSN: 0021-9541
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: There are three types of myeloid leukemic cells, IR+D+, IR+D- and IR-D-. IR+D+ cells were induced to differentiate to granulocytes in mass culture in liquid medium by conditioned medium (CM) from cultures of lungs from mice injected with endotoxin. About 90% of the leukemic cells were induced to differentiate, 50% to mature granulocytes and 40% to intermediate stages. An efficient induction of granulocyte differentiation was also obtained with CM from primary cultures of rat embryo or human spleen and there was a lower activity with CM from various other sources. IR+D- cells were induced to differentiate to about 20% cells with intermediate stages but not to mature granulocytes; IR-D- cells could not be induced to differentiate to intermediate or mature stages. IR+D+ cells were induced to form intermediate stages of granulocyte differentiation, to phagocytose and to attach to the surface of the Petri dish, three days after incubation with CM. Optimum induction of mature granulocytes required six more days incubation with CM. Mature granulocytes induced from leukemic cells showed cytochemical properties and a morphology in the electron microscope similar to that of normal mature granulocytes. These induced granulocytes did not form leukemiac in animals or colonies in agar. The granulocytes induced from the myeloid leukemic cells, therefore, behaved like normal mature granulocytes.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 123 (1985), S. 228-234 
    ISSN: 0021-9541
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Exogenous serine proteases were found to induce differentiation in human myeloid leukemic cells from either in vitro established long-term cell lines or in primary cultures of cells derived directly from patients with acute myeloid leukemia. Exposure of the human promyelocytic cell line HL-60 to trypsin, chymotrypsin, or elastase induced the appearance, within 3-6 days, of neutrophilic granulocytes defined by their morphology, their ability to reduce nitroblue tetrazolium, and their efficient phagocytosis of latex particles. Upon further incubation monocytelike cells appeared. While these cells developed into fully mature macrophages other types of cells disappeared and on day 12 the culture consisted of a pure macrophage population. The inducing effect could be observed when the enzyme was presented alone, whereas a synergistic effect was noted when the protease was added in the presence of subthreshold concentrations of chemicals known to induce differentiation in this cell line such as dimethylsulfoxide, retinoic acid, butyric acid, or hexamethylene bisacetamide. Optimal induction of differentiation by trypsin required a 48 hr continuous exposure to the enzyme. When the protease was removed earlier no appreciable differentiation was noticed. The protease-induced differentiation involved a direct interaction with the cells and was not due to a proteolytic cleavage of a serum component because it could be obtained in serum-free cultures. The enzymatic activity of the protease was needed for its effect on cell maturation: Addition of protease inhibitors such as soybean-trypsin inhibitor or trasylol completely blocked differentiation induced by the proteases but had no effect on differentiation induced by the other inducers. It is still to be determined whether a proteolytic process is a general molecular event in cell differentiation or induction by chemicals involves a mechanism different from that initiated by exogenous proteases.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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