Hans-Jürgen Ahr

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Recently, tissue engineering has merged with stem cell technology with interest to develop new sources of transplantable material for injury or disease treatment. Eminently interesting, are bone and joint injuries/disorders because of the low self-regenerating capacity of the matrix secreting cells, particularly chondrocytes. ES cells have the unlimited(More)
Eker rats heterozygous for a dominant germline mutation in the tuberous sclerosis 2 (Tsc2) tumor suppressor gene were used as a model to study renal carcinogenesis. Eker and corresponding wild-type rats were exposed to genotoxic aristolochic acid (AA) or non-genotoxic ochratoxin A (OTA) to elucidate early carcinogen-specific gene expression changes and to(More)
Cultivated hepatocytes represent a well-established in vitro system. However, the applicability of hepatocytes in toxicogenomics is still controversially discussed. Recently, an in vivo/in vitro discrepancy has been described, whereby the non-genotoxic rat liver carcinogen methapyrilene alters the expression of the metabolizing genes SULT1A1 and ABAT, as(More)
Despite about two decades of research in the field of endocrine active compounds, still no validated human recombinant (hr) estrogen receptor-alpha (ERalpha) binding assay is available, although hr-ERalpha is available from several sources. In a joint effort, US EPA and Bayer Schering Pharma with funding from the EU-sponsored 6th framework project,(More)
The elicitation of respiratory allergy in animal models is exquisitely complex and interpretation of results from different laboratories cannot readily be compared due to variability in testing protocols, biomarkers and techniques used to identify 'positive' responses. On the one hand, guinea-pigs have been proposed as a good model with which to study(More)
Specific genotoxic events such as gene mutations and/or chromosome damage are considered hallmarks of cancer. The genotoxicity testing battery enables relatively simple, rapid and inexpensive hazard identification, namely by assessing a chemical's ability to cause genetic damage in cells. In addition, the 2-year rodent carcinogenicity bioassay provides an(More)
There is an acknowledged need to promote and further develop in vitro techniques in order to achieve the goal of improved risk assessment of chemicals and pharmaceuticals to humans. The EU 6th framework project "PREDICTOMICS" was established in order to contribute to the further development of in vitro toxicology, with a particular focus on emerging(More)
After repeated-dose toxicity studies with the fungicide propineb, reversible effects on muscle functions were found. Therefore, mechanistic investigations should contribute to clarification of its mode of action in relation to disulfiram and diethyldithiocarbamate neurotoxicity or direct effects on muscle cells. In principle, besides the dithiocarbamate(More)
This is the report of the first workshop "Validation of Toxicogenomics-Based Test Systems" held 11-12 December 2003 in Ispra, Italy. The workshop was hosted by the European Centre for the Validation of Alternative Methods (ECVAM) and organized jointly by ECVAM, the U.S. Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM),(More)