Compressive instabilities enable cell-induced extreme densification patterns in the fibrous extracellular matrix: Discrete model predictions.

We present a new model and extensive computations that explain the dramatic remodelling undergone by a fibrous collagen extracellular matrix (ECM), when subjected to contractile mechanical forces from embedded cells or cell clusters. This remodelling creates complex patterns, comprising multiple narrow localised bands of severe densification and fiber alignment, extending far into the ECM, often joining distant cells or cell clusters (such as tumours). Most previous models cannot capture this behaviour, as they assume stable mechanical fiber response with stress an increasing function of fiber stretch, and a restriction to small displacements.

Cells exploit a phase transition to mechanically remodel the fibrous extracellular matrix.

Through mechanical forces, biological cells remodel the surrounding collagen network, generating striking deformation patterns. Tethers-tracts of high densification and fibre alignment-form between cells, thinner bands emanate from cell clusters. While tethers facilitate cell migration and communication, how they form is unclear.

Exploring the competition between proliferative and invasive cancer phenotypes in a continuous spatial model.

Tumor is characterized by extensive heterogeneity with respect to its microenvironment and its genetic composition. We extend a previously developed monoclonal continuous spatial model of tumor growth to account for polyclonal cell populations and investigate the interplay between a more proliferative and a more invasive phenotype under different conditions. The model simulations demonstrate a transition from the dominance of the proliferative to the dominance of the invasive phenotype resembling malignant tumor progression and show a time period where both subpopulations are abundant.

Employing in-vivo molecular imaging in simulating and validating tumor growth.

During the last decades, especially via the EU initiative related to the Virtual Physiological Human, significant progress has been made in advancing "in-silico" computational models to produce accurate and reliable tumor growth simulations. However, currently most attempts to validate the outcome of the models are either done in-vitro or ex-vivo after tumor resection. In this work, we incorporate information provided by fluorescence molecular tomography performed in-vivo into a mathematical model that describes tumor growth.

Right-sided implantation of a cardiac resynchronization therapy defibrillator in a case of persistent left superior vena cava.

Persistent left superior vena cava represents a congenital venous anomaly that poses a particular obstacle to the implantation of cardiac rhythm management devices. In the present report we briefly describe the rightsided implantation of a biventricular defibrillator in a patient with persistent left superior vena cava. We also briefly discuss the technically challenging procedures applied in such cases.