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During the last two decades, substantial efforts have been made towards the development and international acceptance of alternative methods to safety studies using laboratory animals. In the EU, challenging timelines for phasing out of many standard tests using laboratory animals were established in the seventh Amending Directive 2003/15/EC to Cosmetics(More)
Queen pheromones interfere with worker reproduction in social insects. However, there is still an unresolved question as to whether this pheromone acts as an “honest” signal for workers, giving a reliable indication of the queen’s reproductive value, or as a suppressive agent, inhibiting worker reproduction independent of the queen’s reproductive capacity.(More)
Currently, comprehensive toxicological data are available only for a small percentage of the 30,000 substances produced in volumes of 1–100 tons per year in the EU. Substances with inadequate safety data sets may pose a risk to employees, consumers and the environment. To improve this unsatisfactory situation the European Commission put forward a draft(More)
Multidrug resistance type 1 P-glycoproteins (P-gp) and multidrug resistance associated proteins (MRP) were studied in differentiated primary human lung cells in culture, in comparison with permanent human lung cell lines and primary alveolar type II cells from rat lung. AII cells exhibited low basal levels of mdr1b mRNA, that increased over time and after(More)
Intestinal absorption, bioavailability, hepatic and pulmonary extraction and elimination of low doses of benzo[a]pyrene (BP; 0.7-4.4 nmol) were studied in the rat using [G-3H]BP. The hepatic extraction ratio was 0.4 both in a liver perfusion model and in vivo as determined by comparison of intravenous and intraportal infusion experiments in anaesthetized(More)
Existing systems of classification of carcinogens are a matter of discussion, world-wide. There is agreement that it should be distinguished between genotoxic and non-genotoxic chemicals. The risk assessment approach used for non-genotoxic chemicals is similar among different regulatory bodies: insertion of an uncertainty (safety) factor permits the(More)
Covalent binding of benzo(a)pyrene to DNA, RNA, and protein of perfused rat lung after intratracheal administration of the substrate was about 50% of that obtained by direct addition of the substrate into the perfusate. Systemic availability of benzo(a)pyrene by absorption from the intratracheal sites was found to be 25%. During single pass perfusion of rat(More)
The kinetics of nicotine elimination was investigated in isolated perfused lung and liver of phenobarbital (PB)- and 5,6-benzoflavone (BF)-pretreated rats. The estimated kinetic parameters demonstrated a high nicotine elimination rate in rat lung approaching the capacity of liver when both organs were in an uninduced state. The concentration-time profiles(More)
Nanotechnology offers enormous potential for technological progress. Fortunately, early and intensive efforts have been invested in investigating toxicology and safety aspects of this new technology. However, despite there being more than 6,000 publications on nanotoxicology, some key questions still have to be answered and paradigms need to be challenged.(More)
The existing systems of classification of carcinogens should include a distinction between genotoxic and non-genotoxic chemicals. For non-genotoxic chemicals, permissible exposure levels can be derived at which no relevant human cancer risks are anticipated. While genotoxic carcinogens can induce chromosomal effects without mutagenic action,(More)