Assessment of in silico models for acute aquatic toxicity towards fish under REACH regulation.

We evaluated the performance of eight QSAR in silico modelling packages (ACD/ToxSuite™, ADMET Predictor™, DEMETRA, ECOSAR, TerraQSAR™, Toxicity Estimation Software Tool, TOPKAT™ and VEGA) for acute aquatic toxicity towards two species of fish: Fathead Minnow and Rainbow Trout. For the Fathead Minnow, we compared model predictions for 567 substances with the corresponding experimental values for 96-h median lethal concentrations (LC50). Some models gave good results, with r up to 0.

Comparison of in silico models for prediction of Daphnia magna acute toxicity.

Eight in silico modelling packages were evaluated and compared for the prediction of Daphnia magna acute toxicity from the viewpoint of the European legislation on chemicals, REACH. We tested the following models: Discovery Studio (DS) TOPKAT, ACD/Tox Suite, ADMET Predictor, ECOSAR (Ecological Structure Activity Relationships), TerraQSAR, T.E.

Mutagenicity, carcinogenicity, and other end points.

Aiming at understanding the structural and physical chemical basis of the biological activity of chemicals, the science of structure-activity relationships has seen dramatic progress in the last decades. Coarse-grain, qualitative approaches (e.g.

Assessment and validation of US EPA's OncoLogic® expert system and analysis of its modulating factors for structural alerts.

OncoLogic® is a software program able to screen chemical compounds for toxicological effects. The software predicts the potential carcinogenicity of chemicals by applying rules of structure activity relationship (SAR) analysis. To validate the predictivity of OncoLogic® (Version 7.

Peri-implant squamous odontogenic tumor.

Squamous odontogenic tumor (SOT) is a benign, locally infiltrative intraosseous tumor composed of well-differentiated squamous epithelium in a fibrous stroma. It seems to derive from the epithelial rests of Malassez in the periodontal ligament space. It presents an odontogenic origin, involving both the upper and lower maxillary bone, mainly areas without teeth or connective tissue of the odontogenic cysts.