Steffi Ritter

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The descendants of irradiated fibroblasts undergo stepwise senescence and differentiation, but genetic instability has also been observed [1]. In the decision of the fate of irradiated cells and their descendents, changes in the cellular redox status play an important role [2]. An accumulation of reactive oxygen species (ROS) in cells following irradiation(More)
Introduction: According to the “free-radical theory of ageing” during ageing elevated levels of free radicals and reactive oxygen species (ROS) induce damages of lipids, proteins and nucleic acids in cells (1). Enhanced oxidative damage shortens lifespan (2). In mitochondria ~90% of the total cellular ROS is produced mostly by respiration. Respiratory chain(More)
The long-term "fate" of normal human cells after single hits of charged particles is one of the oldest unsolved issues in radiation protection and cellular radiobiology. Using a high-precision heavy-ion microbeam we could target normal human fibroblasts with exactly one or five carbon ions and measured the early cytogenetic damage and the late behaviour(More)
Xenogenic transplantation models have been developed to study human hematopoiesis in immunocompromised murine recipients. They still have limitations and therefore it is important to delineate all players within the bone marrow that could account for species-specific differences. Here, we evaluated the proliferative capacity, morphological and physical(More)
Apoptotic cell death is a common feature after exposure to ionising radiation in vivo and in vitro. Macrophages are responsible for the phagocytotic clearance of the apoptotic cells and it was shown that phagocytosis of radiation-induced apoptotic cells can activate macrophages, leading them to the induction of an inflammatory response in the surrounding(More)
Introduction Former experiments have shown an increase in number of unstable chromosomal aberrations in normal human fibroblast strains with ongoing culturing time of the populations [1, 2]. These de novo formed unstable aberrations are an indicator of genomic instability which is considered to be one important step towards carcinogenesis. In the same(More)
Since the start of C-ion therapy at GSI, Darmstadt, in December 1997 about 340 patients have been treated. Most patients had chordoma or low grade chondrosarcoma of the skull base. Based on the promising clinical results, namely high local control rates and mild side effects [1], the application has been recently extended to intermediate risk prostate(More)
Health hazards resulting form the exposure to high-Z and high energy particles such as carcinogenesis, damage to the central nervous system or cataractogenesis are of major concern in planning manned missions to Moon and Mars. Among these effects carcinogenesis is currently considered to be the main risk factor for astronauts. One important biomarker of(More)
Growth and reproduction of cells is described by their passage through the cell cycle. In case of DNA damage, such as caused by ionizing radiation, fibroblasts suspend dividing. It is discussed that such delay, in form of a transient arrest, provides fibroblasts with time for repair, while a permanent arrest removes aberrant fibroblasts from the(More)
Telomeres are the physical ends of the linear eukaryotic chromosomes. Telomere erosion during DNA replication is considered to be the main cause of the onset of replicative senescence, an irreversible cell cycle arrest at the end of the lifespan of normal cells (1). With the help of a number of proteins, including the telomere repeat-binding factor 2(More)