Laura L. Custer

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The Syrian hamster embryo (SHE) cell-transformation assay represents a short-term in vitro assay capable of predicting rodent carcinogenicity of chemicals with a high degree of concordance (LeBoeuf et al [1996]. Mutat Res 356: 85-127). The SHE assay models the earliest identifiable stage in carcinogenicity, morphological cell transformation. In contrast to(More)
The Syrian hamster embryo (SHE) cell transformation assay evaluates the potential of chemicals to induce morphological transformation in karyotypically normal primary cells. Induction of transformation has been shown to correlate well with the carcinogenicity of many compounds in the rodent bioassay. Historically the assay has not received wide-spread use(More)
Classification models were developed to provide accurate prediction of genotoxicity of 277 polycyclic aromatic compounds (PACs) directly from their molecular structures. Numerical descriptors encoding the topological, geometric, electronic, and polar surface area properties of the compounds were calculated to represent the structural information. Each(More)
Appropriate follow-up actions and decisions are needed when evaluating and interpreting clear positive results obtained in the in vitro assays used in the initial genotoxicity screening battery (i.e., the battery of tests generally required by regulatory authorities) to assist in overall risk-based decision making concerning the potential effects of human(More)
A collaborative international trial was conducted to evaluate the reproducibility and transferability of an in vivo mutation assay based on the enumeration of CD59-negative rat erythrocytes, a phenotype that is indicative of Pig-a gene mutation. Fourteen laboratories participated in this study, where anti-CD59-PE, SYTO 13 dye, and flow cytometry were used(More)
Binary quantitative structure-activity relationship (QSAR) models are developed to classify a data set of 334 aromatic and secondary amine compounds as genotoxic or nongenotoxic based on information calculated solely from chemical structure. Genotoxic endpoints for each compound were determined using the SOS Chromotest in both the presence and absence of an(More)
We report several binary classification models that directly link the genetic toxicity of a series of 140 thiophene derivatives with information derived from the compounds' molecular structure. Genetic toxicity was measured using an SOS Chromotest. IMAX (maximal SOS induction factor) values were recorded for each of the 140 compounds both in the presence(More)
Genotoxicity hazard identification is part of the impurity qualification process for drug substances and products, the first step of which being the prediction of their potential DNA reactivity using in silico (quantitative) structure-activity relationship (Q)SAR models/systems. This white paper provides information relevant to the development of the draft(More)
N-methyl-N-nitrosourea (MNU) was evaluated in the in vivo Pig-a mutation assay as part of an International Collaborative Trial to investigate laboratory reproducibility, 28-day study integration, and comparative analysis with micronucleus (MN), comet, and clinical pathology endpoints. Male Sprague Dawley rats were treated for 28 days with doses of 0, 2.5,(More)
Genetic toxicity tests currently used to identify and characterize potential human mutagens and carcinogens rely on measurements of primary DNA damage, gene mutation, and chromosome damage in vitro and in rodents. The International Life Sciences Institute Health and Environmental Sciences Institute (ILSI-HESI) Committee on the Relevance and Follow-up of(More)