The use of accident reconstruction for the analysis of traumatic brain injury due to head impacts arising from falls

Brain injury is the leading cause of death in those aged under 45 years in both Europe and the USA. The objective of this research is to reconstruct and analyse real world cases of accidental head injury, thereby providing accurate data, which can be used subsequently to develop clinical tolerance levels associated with particular traumatic injuries and brain lesions. This paper looks at using numerical modelling techniques, namely multibody body dynamics and finite element methods, to reconstruct two real-life accident cases arising from falls. Preliminary results show the levels of acceleration of the head and deformation of brain tissue correspond well to those found by other researchers, suggesting that this method is suitable for modeling head-injury accidents.Deposited by bulk import1/10/2013. SB

Modulation of Fibroblast Morphology and Adhesion during Collagen Matrix Remodeling

When fibroblasts are placed within a three-dimensional collagen matrix, cell locomotion results in translocation of the flexible collagen fibrils of the matrix, a remodeling process that has been implicated in matrix morphogenesis during development and wound repair. In the current experiments, we studied formation and maturation of cell–matrix interactions under conditions in which we could distinguish local from global matrix remodeling. Local remodeling was measured by the movement of collagen-embedded beads towards the cells. Global remodeling was measured by matrix contraction. Our observations show that no direct relationship occurs between protrusion and retraction of cell extensions and collagen matrix remodeling. As fibroblasts globally remodel the collagen matrix, however, their overall morphology changes from dendritic to stellate/bipolar, and cell–matrix interactions mature from punctate to focal adhesion organization. The less well organized sites of cell–matrix interaction are sufficient for translocating collagen fibrils, and focal adhesions only form after a high degree of global remodeling occurs in the presence of growth factors. Rho kinase activity is required for maturation of fibroblast morphology and formation of focal adhesions but not for translocation of collagen fibrils