Cadmium-transformed cells in the in vitro cell transformation assay reveal different proliferative behaviours and activated pathways.

The in vitro Cell Transformation Assay (CTA) is a powerful tool for mechanistic studies of carcinogenesis. The endpoint is the classification of transformed colonies (foci) by means of standard morphological features. To increase throughput and reliability of CTAs, one of the suggested follow-up activities is to exploit the comprehension of the mechanisms underlying cell transformation. To this end, we have performed CTAs testing CdCl2, a widespread environmental contaminant classified as a human carcinogen with the underlying mechanisms of action not completely understood. We have isolated and re-seeded the cells at the end (6weeks) of in vitro CTAs to further identify the biochemical pathways underlying the transformed phenotype of foci. Morphological evaluations and proliferative assays confirmed the loss of contact-inhibition and the higher proliferative rate of transformed clones. The biochemical analysis of EGFR pathway revealed that, despite the same initial carcinogenic stimulus (1µM CdCl2 for 24h), transformed clones are characterized by the activation of two different molecular pathways: proliferation (Erk activation) or survival (Akt activation). Our preliminary results on molecular characterization of cell clones from different foci could be exploited for CTAs improvement, supporting the comprehension of the in vivo process and complementing the morphological evaluation of foci.

Objective scoring of transformed foci in BALB/c 3T3 cell transformation assay by statistical image descriptors.

In vitro cell transformation assays (CTAs) have been shown to model important stages of in vivo carcinogenesis and have the potential to predict carcinogenicity in humans. Advantages of CTAs are their ability of revealing both genotoxic and non-genotoxic carcinogens while reducing both experimental costs and the number of animals used. The endpoint of the CTA is foci formation, and requires classification under light microscopy based on morphology. Thus current limitations for the wide adoption of the assay partially depend on a fair degree of subjectivity in foci scoring. An objective evaluation may be obtained after separating foci from background monolayer in the digital image, and quantifying values of statistical descriptors which are selected to capture eye-scored morphological features. The aim of this study was to develop statistical descriptors to be applied to transformed foci of BALB/c 3T3, which cover foci size, multilayering and invasive cell growth into the background monolayer. Proposed descriptors were applied to a database of 407 foci images to explore the numerical features, and to illustrate open problems and potential solutions.

[Management of gastrointestinal bleeding in Veneto Region, Italy]. / Gestione delle emorragie digestive nella Regione Veneto.

Gastrointestinal bleeding (GB) is still a common medical emergency and an important cause of morbidity and mortality. There is clear evidence that early endoscopic intervention is effective in reducing mortality, length of stay and surgery procedures utilization in high-risk patients. In the last decades advances in medical practice and in endoscopic technology have influenced the management of GB, but their impact on the incidence and mortality is unclear. The aim of this study was to evaluate retrospectively time trends (2000-2007) in GB hospitalizations and in-hospital mortality, and describe the organization of endoscopic services of Veneto region, Italy. Data were collected from regional database of hospital discharge from 2000 to 2007 and all patients with an ICD 9-CM discharge diagnosis of GB were included. Overall hospitalization and in-hospital mortality rates were respectively 99.3 and 4.5 per 100.000 inh./year, the last being related to older age. Surgery procedures utilization was 5%. Hospitalization and mortality rates decreased significantly over years, probably owing to advances in the acute management of GB, principally represented by endoscopic procedures.