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001-es BibID:	BIBFORM006047
Első szerző:	Nagy Katalin (orvos)
Cím:	Induction of granulocytic maturation in HL-60 human leukemia cells by free radicals : a hypothesis of cell differentiation involving hydroxyl radicals / Nagy, K., Pasti, G., Bene, L., Zs-Nagy, I.
Dátum:	1993
Megjegyzések:	Tumor cells usually contain lower superoxide dismutase (SOD) activity than differentiating cells, suggesting the involvement of oxygen free radicals in cell maturation. The effects of a system known to produce the OH. radicals were tested on HL-60 cells cultured under optimum conditions for 96 hr. Hydroxyl radicals were generated by a Fenton reaction, involving an ADP-Fe2+ (or ATP-Fe2+) complex and H2O2. Changes induced by OH. were compared to the effects of DMSO-induced differentiation of HL-60 cells. Cell numbers, viability, thymidine incorporation, TPA-induced NBT reduction and propidium iodide staining in flow cytometry were determined. The OH. generating system inhibited the growth and thymidine incorporation of leukemic cells in a manner dependent on the dose of added H2O2 (from 0.005 to 0.05 mM). In addition, an increasing proportion of the treated cells displayed signs of cell differentiation. In DMSO-treated cells, SOD and catalase activities increased after 6 days of culturing. The results show that a portion of the OH. free radicals derived from H2O2, produced by the action of SOD, may be a necessary prerequisite for differentiation, whereas an overproduction of OH. causes cell lethality or aging. We suggest that OH. free radicals may have a more complex role in cell physiology than simply causing oxidative damage.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Aging Catalase Cell Differentiation Cell Division Cell Line Cells cytology Dimethyl Sulfoxide DNA Replication drug effects Flow Cytometry Free Radicals Granulocytes Human Hungary Hydrogen Peroxide Hydroxyl Radical Iron Kinetics Leukemia,Promyelocytic,Acute metabolism Models,Biological pharmacology physiology Propidium Superoxide Dismutase Tetradecanoylphorbol Acetate Thymidine Time Factors Tumor Cells,Cultured
Megjelenés:	Free Radical Research Communications. - 19 : 1 (1993), p. 1-15. -
További szerzők:	Pásti Gabriella Bene László (1963-) (biofizikus) Zs. Nagy Imre
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001-es BibID:	BIBFORM004931
Első szerző:	Nagy Katalin (orvos)
Cím:	Involvement of Fenton reaction products in differentiation induction of K562 human leukemia cells / Nagy, K., Pasti, G., Bene, L., Zs. Nagy, I.
Dátum:	1995
Megjegyzések:	ADP-Fe2+ (or ATP-Fe2+) complex and H2O2, components of the Fenton reaction, were added to K562 cells, then cultured for 96 h. Ara-C-induced differentiation served as a basis for comparison. Cell numbers, viability, benzidine staining, thymidine incorporation, and cell-cycle distribution by means of flow cytometry were determined. The Fenton reagents reduced the growth rate and thymidine incorporation of leukemic cells in a dose-dependent manner as regards the added H2O2 (from 0.01 to 1.0 mM), accompanied by an accumulation of hemoglobin in them. Differentiation of the cells was accompanied by considerable changes in total SOD and catalase activities. Ara-C caused an increase of SOD to 366%, and of catalase to 235%, while the complete Fenton reaction resulted in SOD increase to 705% and catalase decrease to 38% of the untreated control cultures. These shifts in enzyme inductions suggest the existence of a higher H2O2 flux in the differentiating cells. The results are consistent with the assumption that products of the Fenton reaction, among them OH. radicals deriving from H2O2 by heterolysis, may play a causal role in cell differentiation, whereas an overproduction of these radicals causes aging or death of the cells.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Adenosine Diphosphate Aging Benzidines biosynthesis Catalase Cell Cycle Cell Differentiation Cell Division Cells chemistry Dna drug effects Ferrous Compounds Flow Cytometry Human Hydrogen Peroxide Hydroxyl Radical In Vitro Iron metabolism Superoxide Dismutase Thymidine toxicity Tumor Cells
Megjelenés:	Leukemia Research. - 19 : 3 (1995), p. 203-212. -
További szerzők:	Pásti Gabriella Bene László (1963-) (biofizikus) Zs. Nagy Imre
Internet cím:	elektronikus változat DOI elektronikus változat
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