%0 Journal Article %1 Loeffler.1984 %A Loeffler, Markus %A Herkenrath, P. %A Wichmann, Heinz-Erich %A Lord, B. I. %A Murphy, M. J. %D 1984 %J Blut %K IMISE-Publikationen %N 6 %P 427–439 %T The kinetics of hematopoietic stem cells during and after hypoxia. A model analysis %V 49 %X A previously described mathematical model of the hematopoietic stem cell system has been extended to permit a detailed understanding of the data during and after hypoxia. The model includes stem cells, erythroid and granuloid progenitors and precursors. Concerning the intramedullary feedback mechanisms two basic assumptions are made: 1) The fraction ä\" of CFU-S in active cell cycle is regulated. Reduced cell densities of CFU-S, progenitors or precursors lead to an accelerated stem cell cycling. Enlarged cell densities suppress cycling. 2) The self renewal probability \"p\" of CFU-S is also regulated. The normal steady state is described by p = 0.5, indicating that on statistical average each dividing mother stem cell is replaced by one daughter stem cell, while the second differentiates. Diminished cell densities of CFU-S or enlarged densities of progenitors and precursors induce a more intensive self renewal (p greater than 0.5), such that the stem cell number increases. The self renewal probability declines (p less than 0.5) if too many CFU-S or too few progenitors and precursors are present. The model reproduces bone marrow data for CFU-S, BFU-E, CFU-C, CFU-E, 59 Fe-uptake and nucleated cells in hypoxia and posthypoxia. Although the ratio of differentiation into the erythroid and granuloid cell lines is kept constant in the model, a changing ratio of CFU-E and CFU-C results. The model suggests that stem cells and progenitor cells are regulated by a regulatory interference of erythropoiesis and granulopoiesis.

@article{Loeffler.1984, abstract = {A previously described mathematical model of the hematopoietic stem cell system has been extended to permit a detailed understanding of the data during and after hypoxia. The model includes stem cells, erythroid and granuloid progenitors and precursors. Concerning the intramedullary feedback mechanisms two basic assumptions are made: 1) The fraction \"a\" of CFU-S in active cell cycle is regulated. Reduced cell densities of CFU-S, progenitors or precursors lead to an accelerated stem cell cycling. Enlarged cell densities suppress cycling. 2) The self renewal probability \"p\" of CFU-S is also regulated. The normal steady state is described by p = 0.5, indicating that on statistical average each dividing mother stem cell is replaced by one daughter stem cell, while the second differentiates. Diminished cell densities of CFU-S or enlarged densities of progenitors and precursors induce a more intensive self renewal (p greater than 0.5), such that the stem cell number increases. The self renewal probability declines (p less than 0.5) if too many CFU-S or too few progenitors and precursors are present. The model reproduces bone marrow data for CFU-S, BFU-E, CFU-C, CFU-E, 59 Fe-uptake and nucleated cells in hypoxia and posthypoxia. Although the ratio of differentiation into the erythroid and granuloid cell lines is kept constant in the model, a changing ratio of CFU-E and CFU-C results. The model suggests that stem cells and progenitor cells are regulated by a regulatory interference of erythropoiesis and granulopoiesis.}, added-at = {2014-10-17T12:55:43.000+0200}, author = {Loeffler, Markus and Herkenrath, P. and Wichmann, Heinz-Erich and Lord, B. I. and Murphy, M. J.}, biburl = {https://www.bibsonomy.org/bibtex/202a15c385b3080ba61418fa6a929ac87/drtester}, interhash = {7363e96a4347aebefe07815599e0dc67}, intrahash = {02a15c385b3080ba61418fa6a929ac87}, journal = {Blut}, keywords = {IMISE-Publikationen}, number = 6, pages = {427–439}, timestamp = {2014-12-02T23:59:43.000+0100}, title = {The kinetics of hematopoietic stem cells during and after hypoxia. A model analysis}, volume = 49, year = 1984 }