Guenther Konwalinka

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CD34+ cells in human cord blood and marrow are known to give rise to dendritic cells (DC), as well as to other myeloid lineages. CD34+ cells are rare in adult blood, however, making it difficult to use CD34+ cells to ascertain if DC progenitors are present in the circulation and if blood can be a starting point to obtain large numbers of these(More)
The potent immunomodulator FTY720 elicits immunosuppression via acting on sphingosine 1-phosphate receptors (S1PR), thereby leading to an entrapment of lymphocytes in the secondary lymphoid tissue. To elucidate the potential in vitro effects of this drug on human monocyte-derived DC, we used low nanomolar therapeutic concentrations of FTY720 and(More)
PURPOSE To our knowledge the exact age dependent morphological and functional changes of the sphincter mechanism have not been investigated. Therefore, cell densities of the urethra and the urethral rhabdosphincter across various age groups, and the appearance of apoptosis were examined to explore the changes in these structures during the aging process. (More)
Natural products are still an untapped source of promising lead compounds for the generation of antineoplastic drugs. Here, we investigated for the first time the antiproliferative and apoptotic effects of highly purified oxindole alkaloids, namely isopteropodine (A1), pteropodine (A2), isomitraphylline (A3), uncarine F (A4) and mitraphylline (A5) obtained(More)
A simple and reproducible micro-agar culture technique for cloning human CFU-M is described. Human bone marrow mononuclear cells were suspended in agar and incubated for 12 days. Stimulation was provided by the direct addition of phytohemagglutinin-P (PHA-P), erythropoietin (Epo) and 2-mercaptoethanol (2-ME) to the liquid overlayer. A shift from BFU-E and(More)
Cross-resistance patterns between chemotherapeutic agents have implications for the treatment of hematologic and other diseases. Previous in vitro models have shown cross-resistance between the purine analog 2-chlorodeoxyadenosine (cladribine) and the pyrimidine analogs 2',2'-difluorodeoxycytidine (gemcitabine) and 1-beta-D-arabinofuranosylcytosine(More)
Myelodysplastic syndrome (MDS) is frequently associated with autoimmune diseases such as polymyalgia, arthritis, and rarely, with systemic vasculitis. The pathogenesis of these autoimmune complications remains unknown, but there is increasing evidence of profound immune dysregulation in MDS. In the few cases reported so far, vasculitides associated with MDS(More)
Mitochondrial damage with release of cytochrome c is implicated in cell death signalling pathways. To examine mitochondrial function in apoptotic cells, we applied high-resolution respirometry to human leukemia cells arrested in the G1- and S-phase by exposure to the glucocorticoid dexamethasone and nucleotide analogue gemcitabine. At 30% apoptosis,(More)
SEW2871 is a potent sphingosine-1-phosphate receptor type-1 (S1P(1))-selective agonist that induces peripheral lymphopenia through sequestration of lymphocytes into secondary lymphoid organs, similar to the non-selective sphingosine-1-phosphate (S1P) receptor agonist FTY720. FTY720 has been reported to interfere with human dendritic cell (DC) effector(More)
Erythropoietin (Epo) was found to act as a concentration-dependent inducer of aminolevulinic acid (ALA) synthase and porphobilinogen (PBG) deaminase in normal human bone marrow in culture. Epo increased enzymatic activities in individual plated nucleated cells. At a low concentration of Epo, heme oxygenase activity did not change in human bone marrow(More)