title: The cell transformation assay: toward a statistical classification of mixed and intermediate foci images.
abstract: The human carcinogenicity evaluation of chemicals has a great impact on public health. In vitro methods, such as the cell transformation assay (CTA), allow for a fast and reliable assessment of the carcinogenic potential of a chemical compound in comparison with the standard two-year bioassay. The scoring and classification of foci in selected cell lines is performed, after staining, by light microscopy. Foci can be separated into three classes: type I, which are scored as non-transformed, and types II and III that are considered to include fully transformed foci. However, in a number of cases, even an expert is uncertain about the attribution of a focus to a given class, due to its mixed or intermediate nature. Here, we suggest a simple approach to classifying mixed or intermediate foci by exploiting the quantitative information available from images, which is captured by statistical descriptors. A quantitative index is proposed, to describe the degree of dissimilarity of mixed and intermediate images to the three well-distinguished classes.
authors: Dipartimento di Scienze dell'Ambiente e del Territorio, Università degli Studi di Milano-Bicocca, Milan, Italy.
authors: Claudio
authors: C
authors: Procaccianti
authors: Federico M
authors: FM
authors: Stefanini
authors: Chiara
authors: C
authors: Urani
mesh_terms: D000826:Animal Testing Alternatives; D000818:Animals; D015197:Carcinogenicity Tests; D002471:Cell Transformation, Neoplastic; D016000:Cluster Analysis; D007091:Image Processing, Computer-Assisted; D051379:Mice; D008853:Microscopy