Martin Nowak

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Tumor micromilieu often shows pronounced acidosis forcing cells to adapt their phenotype towards enhanced tumorigenesis induced by altered cellular signalling and transcriptional regulation. In the presents study mechanisms and potential consequences of the crosstalk between extra- and intracellular pH (pH(e), pH(i)) and mitogen-activated-protein-kinases(More)
Because solid growing tumors often show hypoxia and pronounced extracellular acidosis, the aim of this study was to analyze the impact of an acidotic environment on the activity of the p-glycoprotein (pGP) and on the cellular content and cytotoxicity of the chemotherapeutic drug daunorubicin in the AT1 R-3327 Dunning prostate carcinoma cell line cultured in(More)
Due to inadequate perfusion, tumors develop hypoxia and extracellular acidosis. In vitro, this acidic environment (pH=6.6) has a strong impact on the activity of the p-glycoprotein (pGP) drug transporter responsible for multidrug resistance. This effect is most probably mediated via p38 and/or ERK1/2 signalling pathways. The aim of the study was to analyze(More)
There is only limited understanding of the impact of high p(CO2) on soil biomes. We have studied a floodplain wetland where long-term emanations of temperate volcanic CO2 (mofettes) are associated with accumulation of carbon from the Earth's mantle. With an integrated approach using isotope geochemistry, soil activity measurements and multi-omics analyses,(More)
Extracellular acidosis in tumors leads to an activation of the p-glycoprotein (Pgp) drug transporter. In the present study the cytotoxicity of different chemotherapeutic drugs and its dependence on the Pgp activity during acidosis were analyzed in vitro and in vivo. Treating R3327-AT1, Pgp-positive tumor cells at pH 7.4 with daunorubicin, cisplatin or(More)
A newly developed isotope ratio laser spectrometer for CO2 analyses has been tested during a tracer experiment at the Ketzin pilot site (northern Germany) for CO2 storage. For the experiment, 500 tons of CO2 from a natural CO2 reservoir was injected in supercritical state into the reservoir. The carbon stable isotope value (δ(13)C) of injected CO2 was(More)
Due to pronounced hypoxia in many tumors the cells force glycolytic metabolism leading to an acidic environment, low glucose and high lactate levels as well as ATP depletion [ 1 ] . In addition, intermittent blood fl ow in solid tumors [ 2 ] results in ischemia–reperfusion and by this force the formation of reactive oxygen species (ROS) [ 3 ] . These(More)
Optimizing thin film deposition techniques requires contamination-free transfer from the reactor into an ultrahigh vacuum (UHV) chamber for surface science analysis. A very compact, multifunctional Chemical Vapor Deposition (CVD) reactor for direct attachment to any typical UHV system for thin film analysis was designed and built. Besides compactness, fast,(More)