TY  - JOUR
A1  - Lehrnbecher, T.
A1  - Merz, H.
A1  - Sebald, Walter
A1  - Poot, M.
T1  - Interleukin 4 drives phytohemagglutinin-activated T cells through several cell cycles: no synergism between interleukin 2 and interleukin 4
N2  - Cell kinetic studies of T cells stimulated with the interleukin 2 (11-2), D-4, or both lymphokines were performed with conventional [3H] thymidine incorporation and with the bivariate BrdU/Hoechst technique. 11-2 and 11-4 are able to drive phytohemagglutininactivated T cells through more than one cell cycle. Neither synergistic nor inhibitory efl'ect on T -cell proliferationwas seen for the stimulation with both 11-2 and 11-4 as compared with the effect ofll-2 alone. The quantitative data ofthe cell cycle distribution ofphytohemagglutininactivated T cells suggestthat the population ofll-4-responsive cells is at least an overlapping population, if not a real subset of the ·population of the 11-2-responsive cells.
KW  - Biochemie
KW  - BrdU-Hoechst
KW  - cell cycle
KW  - flow cytometry
KW  - interleukin 2
KW  - interleukin 4
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62491
ER  - 
TY  - JOUR
A1  - Lehrnbecher, T.
A1  - Poot, M.
A1  - Orscheschek, K.
A1  - Sebald, Walter
A1  - Feller, A. C.
A1  - Merz, H.
T1  - Interleukin 7 as interleukin 9 drives phytohemagglutinin-activated T cells through several cell cycles; no synergism between interleukin 7, interleukin 9 and interleukin 4
N2  - The effects of the interlenkins IL-7 and IL-9 on cell cycle progression were investigated by conventional [3H]thymidine incorporation and by the bivariate BrdU/Hoechst technique. 8oth IL· 7 and IL-9 drive phytohemagglutinin-activated T cells through more than one cell cycle, but IL-7 wasmorepotent on cell cycle progression than IL-9. Neither synergistic nor inhibitory effects were seen between various combinations of the lymphokines IL-7, IL-9 and IL-4 compared to each lymphokine alone. When T cells are activated with phytohemagglutinin for 3 days, all or most IL-4 responsive cells respond to IL-7 as weil, whereas only a part of IL-7 responders are IL-4 responders. In contrast, when T cells are activated with phytohemagglutinin for 7 days, the quantitative data of the cell cycle distribution soggest that the population of IL-7 responders is at least an overlapping, if not a real subset of the population of the IL-4 responders.
KW  - Biochemie
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62438
ER  - 
TY  - JOUR
A1  - Stopper, Helga
A1  - Kirchner, S.
A1  - Schiffmann, D.
A1  - Poot, M.
T1  - Cell cycle disturbance in relation to micronucleus formation induced by the carcinogenic estrogen diethylstilbestrol
N2  - In addition to its tumor-promoting activity in honnone-receptive tissue, the carcinogenic estrogen diethylstilbestrol (DES) has been found to induce cell transformation, aneuploidy and micronucleus formation in mammalian cells. The majority of these micronuclei contained whole chromosomes and were fonned during mitosis. Here a possible relationship between a disturbance in cell cycle progression and micronucleus fonnation is investigated by exposing Syrian hamster embryo (SHE) cells to DES. Continuous bromodeoxyuridine labeling followed by bivariate Hoechst 33258/ethidium bromide flow cytometry was employed for analysis of cell cycle transit and related to the time course of micronucleus formation. Treatment of SHE cells with DES resulted in delayed and impaired cell activation (exit from the GO/G 1 phase), impaired S-phase transit and, mainly, G2-phase traverse. Cells forming micronuclei, on the other hand, were predominantly in G2 phase during DES treatment. These results suggest that impairment of Sand G2 transit may involve a process ultimately leading to micronucleus formation.
KW  - Toxikologie
KW  - Flow cytometry
KW  - Micronucleus formation
KW  - Diethylstilbestrol
KW  - Hoechst 33258 dye
KW  - Bromodeoxyuridine labeling
KW  - continuous
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-82250
ER  -