1974 - 1985 | Mechanistic research on the induction of mouse liver tumours by non-genotoxic compounds. The organochlorine insecticide dieldrin served as a model substance. The most important results of these investigations were:
- The demonstration in a chronic mouse study of a relationship between dieldrin-induced increases in liver DNA and mouse liver tumour formation [Cancer Research 41, 3615-3620 (1981)];
- The elucidation, in mathematical terms, of the dose-response relationship of a non-genotoxic carcinogen [Carcinogenesis 6, 1457-1462 (1985)];
- The demonstration of a close association of tumour formation with nuclear polyploidisation in mouse hepatocytes [Carcinogenesis 8, 265-269 (1987)]
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1985 - 1992 | Direction of numerous general toxicity and carcinogenicity studies with pharmaceuticals and agrochemicals. Successful management of the general toxicology department of a major European contract research laboratory leading to rapid expansion of services. First introduction in the world of computerised dosing equipment in general and reproduction toxicity studies in 1988 |
1992 - present | Consultancy services to leading companies in the chemical industry with an acknowledged record of achievement. |
1992 - 1998 | Secretary of the Toxicology Section of the Swiss Society of Pharmacology and Toxicology |
1996 - 2000 | Member of the Board of Directors of the Swiss Register of Toxicologists |
1995 | Chairman of the Task Force of the Swiss Society of Pharmacology and Toxicology on Guidelines for Training and Registration of Toxicologists in Switzerland. The recommendations of the Task Force were adopted by the Society for the establishment of a Swiss Register of Toxicologists (with EUROTOX certification) and a post-graduate training programme for toxicologists in Switzerland |
2002 - 2004 | The demonstration in outbred and inbred rat strains that (spontaneous) carcinogenesis is genetically determined and that non-genotoxic carcinogens operate by facilitating the expression of tumour predisposition in target cells [Regulatory Toxicology and Pharmacology, 36, 86-95; 40, 18-27; 40, 293-304] |
2009 - 2011 | Discovery that the Druckrey-Küpfmüller equation d t n = constant (where d= daily dose and t = exposure time to effect, with n ≥ 1) for chemical carcinogens also applies to the toxicity of neonicotinoid insecticides to arthropods (Toxicology, 276, 1-4), which provides a plausible explanation for cumulative toxicity that may result in colony collapse disorder (CCD) of honeybees. Publication of a book on the hazards of neonicotinoid insecticides to insects and birds. |
