Matches in SemOpenAlex for { <https://semopenalex.org/work/W832734091> ?p ?o ?g. }
Showing items 1 to 69 of
69
with 100 items per page.
- W832734091 abstract "Recent evaluations of the regulatory in vitro genotoxicity tests have revealed that the mammalian cell tests are sensitive for the prediction of rodent carcinogenicity, but not very specific; they produce positive results for many non-carcinogens. Studies to investigate the potential causes of this poor specificity have focused on the high test concentrations of chemicals and the often associated high cytotoxicity. Others have sought to develop alternative in vitro assays that retain high sensitivity but also have higher specificity. One such test is the GADD45a-GFP ?GreenScreen HC? genotoxicity assay, which uses elements of the cellular DNA damage response in a green fluorescent protein (GFP) reporter system to detect genotoxic hazard. Published validation studies for this assay have shown both high sensitivity and high specificity. Suggestions that the high specificity of the assay is attributable to the method of cytotoxicity estimation, relative cell density (RCD), and further that this method leads to overestimation of cytotoxicity and hence lower maximum test concentrations, are investigated in this study.In order to investigate whether high specificity of the GADD45a-GFP assay is a result of inaccurate estimation of cytotoxicity, RCD was compared with other cytotoxicity methods used in screening assays, as well as the cytotoxicity methods used in the regulatory in vitro mammalian genotoxicity tests. Results showed that RCD actually underestimates cytotoxicity in the GADD45-GFP assay and as a consequence, test data are collected up to and beyond the cytotoxicity-limited test concentrations reached in the regulatory tests. The use of RCD was found not to contribute to the high specificity of the GADD45a-GFP assay and indeed, its high specificity was retained regardless of the method used to estimate cytotoxicity.A largely overlooked element in the consideration of the poor specificity of in vitro mammalian genotoxicity assays is the supplementation of assays with exogenous metabolism systems, the most common of which is ?S9?, a liver-derived preparation. S9 is used to enable the detection of compounds (pro-genotoxins) that undergo metabolic transformation in vivo resulting in the formation of genotoxic carcinogens. However, both the preparation and usage of S9 create a bias towards phase I metabolism, specifically the cytochrome P450 monooxygenases that can catalyse the formation of DNA-reactive species. The neglect of phase II metabolism (detoxification/conjugation) could potentially contribute to the poor specificity of the in vitro mammalian tests and this was explored in the study presented.A review of published data revealed that the prevalence of positive results amongst in vitro mammalian genotoxicity data generated in the presence of S9 was similar in collections of both rodent carcinogens and non-carcinogens. Thus, any increased sensitivity from using S9 is offset by decreased specificity for these tests. However, as inclusion of S9 affected sensitivity and specificity in equal measure it was concluded that S9 is not a confounding factor on the accuracy of the in vitro mammalian genotoxicity tests." @default.
- W832734091 created "2016-06-24" @default.
- W832734091 creator A5080212897 @default.
- W832734091 date "2011-09-19" @default.
- W832734091 modified "2023-09-23" @default.
- W832734091 title "ANALYSIS OF THE POSSIBLE CONFOUNDING EFFECTS OF CYTOTOXICITY AND EXOGENOUS METABOLISM ON IN VITRO GENOTOXICITY ASSESSMENTS" @default.
- W832734091 hasPublicationYear "2011" @default.
- W832734091 type Work @default.
- W832734091 sameAs 832734091 @default.
- W832734091 citedByCount "0" @default.
- W832734091 crossrefType "dissertation" @default.
- W832734091 hasAuthorship W832734091A5080212897 @default.
- W832734091 hasConcept C109316439 @default.
- W832734091 hasConcept C114246631 @default.
- W832734091 hasConcept C143425029 @default.
- W832734091 hasConcept C153911025 @default.
- W832734091 hasConcept C178790620 @default.
- W832734091 hasConcept C185592680 @default.
- W832734091 hasConcept C202751555 @default.
- W832734091 hasConcept C2778959862 @default.
- W832734091 hasConcept C29730261 @default.
- W832734091 hasConcept C33070731 @default.
- W832734091 hasConcept C33618052 @default.
- W832734091 hasConcept C552990157 @default.
- W832734091 hasConcept C55493867 @default.
- W832734091 hasConcept C86803240 @default.
- W832734091 hasConcept C98274493 @default.
- W832734091 hasConceptScore W832734091C109316439 @default.
- W832734091 hasConceptScore W832734091C114246631 @default.
- W832734091 hasConceptScore W832734091C143425029 @default.
- W832734091 hasConceptScore W832734091C153911025 @default.
- W832734091 hasConceptScore W832734091C178790620 @default.
- W832734091 hasConceptScore W832734091C185592680 @default.
- W832734091 hasConceptScore W832734091C202751555 @default.
- W832734091 hasConceptScore W832734091C2778959862 @default.
- W832734091 hasConceptScore W832734091C29730261 @default.
- W832734091 hasConceptScore W832734091C33070731 @default.
- W832734091 hasConceptScore W832734091C33618052 @default.
- W832734091 hasConceptScore W832734091C552990157 @default.
- W832734091 hasConceptScore W832734091C55493867 @default.
- W832734091 hasConceptScore W832734091C86803240 @default.
- W832734091 hasConceptScore W832734091C98274493 @default.
- W832734091 hasLocation W8327340911 @default.
- W832734091 hasOpenAccess W832734091 @default.
- W832734091 hasPrimaryLocation W8327340911 @default.
- W832734091 hasRelatedWork W129251135 @default.
- W832734091 hasRelatedWork W1974635327 @default.
- W832734091 hasRelatedWork W1979105963 @default.
- W832734091 hasRelatedWork W1987656699 @default.
- W832734091 hasRelatedWork W1989152046 @default.
- W832734091 hasRelatedWork W2016162941 @default.
- W832734091 hasRelatedWork W2060426931 @default.
- W832734091 hasRelatedWork W2064411087 @default.
- W832734091 hasRelatedWork W2065799137 @default.
- W832734091 hasRelatedWork W2070112012 @default.
- W832734091 hasRelatedWork W2130180983 @default.
- W832734091 hasRelatedWork W2133145334 @default.
- W832734091 hasRelatedWork W2142172254 @default.
- W832734091 hasRelatedWork W2495608380 @default.
- W832734091 hasRelatedWork W2749830926 @default.
- W832734091 hasRelatedWork W2784002561 @default.
- W832734091 hasRelatedWork W2960541789 @default.
- W832734091 hasRelatedWork W2988377356 @default.
- W832734091 hasRelatedWork W80477063 @default.
- W832734091 hasRelatedWork W84089843 @default.
- W832734091 isParatext "false" @default.
- W832734091 isRetracted "false" @default.
- W832734091 magId "832734091" @default.
- W832734091 workType "dissertation" @default.