The hydrogen bonds between bases can be cleaved or whole bases can be eliminat

potency factors were develop which showed higher speci ity for cell lines and congeners than conventional TEFs. 5 Such in vitro TEQ data were used to demonstrate that RTL cells previously had been exposed to PAHs. 6 CDIi Escher and coworkers 7 developed Paclitaxel TEQs for baseline toxicity as a tool to improve interpretation of ecotoxicity testing ofplex environmental samples and mixtures of selected pure substances. They used the bioluminescence inhibition test with where IF i is the induction factor at the concentration c i is the concentration andis the number of concentrations. The CDI accounts for information about both the characteristics of the concentration “response relationship and the intensity of the effects measured.
Howev Seitz note that the concept of the CDI can only be applied for theparison of experiments with the same number of concentrations. The reason for this limitation is the summarization of the calculated quotients of induction factors and related concentrations Evodiamine inhibitor . Th higher test concentrations lead to higher CDIs. Furthermo effects at low concentrations may be overestimat since substances with minor genotoxic effect at low concentrations tend to result in a higher CDI than substances causing a very strong effect at high Orotic acid 65861 concentrations. On the other ha effects at low concentrations are likely to be of greater ecological relevance and should therefore be considered with particular attention. 4 Final similar to I the CDI does not provide quantitative data. J. Environ. Monit. Vibrio scheri and thebined algae test with Pseudokirchneriella subcapitata .
Both tests allow the characterization of nonspeci toxicants with various modes of actions. The algae test also allows the characterization of speci photosynthesis inhibitors. 7 In another approach by Jung with a TEQ conce benzopyrene buy Iniparib equivalents are used for the assessment of carcinogenicity and mutagenicity of polycyclic aromatic hydrocarbons. 8 Since carcinogenici mutagenicity and genotoxicity are often link it is reasonable also to introduce the TEQ concept into the risk assessment of genotoxic agents. Genotoxicity is caused by multiple effects and is not directly related to a single dominant mode of action. Howev an integrative effect such as genotoxicity may contribute to overall toxicity.
7 Th the aim of the present study was to transfer the BioTEQ concept to genotoxicity gonads testing of pure substances as well asplex environmental sampl in order to obtain an integrative endpoint for aparative assessment of genotoxicity. This journal is a The Royal Society of Chemistry Downloaded by New York University on 0 March Published on 8 February. View Online Experimental Model genotoxicants Cyclophosphamide needs to be metabolized by cytochrome dependent monooxygenases into phosphoramide mustar which alkylates the DNA and leads to the formation of crosslinks and single and double strand breaks. 9 Dimethylnitrosamine is metabolized by cytochrome dependent monooxygenases which leads to the formation ofnitrosoalkyla hydroxyalkylamine a al carbenium ions which methylate macromolecules such as DNA and proteins. 0 Th hydrogen bonds between bases can be cleaved or whole bases can be eliminat leading to DNA instability due to apurinic.