Finite Element Analysis to model ischemia experienced in the development of device related pressure ulcers.

Pressure ulcers are a common occurrence of damage to skin. Severity ranges from slightly discoloured skin to full thickness tissue damage which can be fatal in some cases. Engineering effort, typically developing computational models had made significant progress in the understanding and demonstration of the formation mechanism of pressure ulcers with the aetiology of excessive stress however relatively limited attempts had been made to develop relevant models for pressure ulcers caused by ischemia. The aim of this paper is to present evidence of a computational model developed to simulate ischemic pressure ulcer formation and demonstrate the established relationship between the computational data and the acquired clinically relevant experimental data by utilising laser Doppler velocimetry. The application of the presented computational model and the established relationship allows the evaluation of the effect of a mechanical loading to the cutaneous blood flow velocity which is a step closing to understand and evaluate a mechanical load to the formation of pressure ulcers caused by ischemia

Novel M tuberculosis Antigen-Specific T-Cells Are Early Markers of Infection and Disease Progression

Mycobacterium tuberculosis Region-of-Difference-1 gene products present opportunities for specific diagnosis of M. tuberculosis infection, yet immune responses to only two gene-products, Early Secretory Antigenic Target-6 (ESAT-6) and Culture Filtrate Protein-10 (CFP-10), have been comprehensively investigated.T-cell responses to Rv3873, Rv3878 and Rv3879c were quantified by IFN-γ-enzyme-linked-immunospot (ELISpot) in 846 children with recent household tuberculosis exposure and correlated with kinetics of tuberculin skin test (TST) and ESAT-6/CFP-10-ELISpot conversion over six months and clinical outcome over two years.Responses to Rv3873, Rv3878, and Rv3879c were present in 20-25% of contacts at enrolment. Rv3873 and Rv3879c responses were associated with and preceded TST conversion (P=0.02 and P=0.04 respectively), identifying these antigens as early targets of cell-mediated immunity following M. tuberculosis exposure. Responses to Rv3873 were additionally associated with subsequent ESAT-6/CFP-10-ELISpot conversion (P=0.04). Responses to Rv3873 and Rv3878 predicted progression to active disease (adjusted incidence rate ratio [95% CI] 3.06 [1.05,8.95; P=0.04], and 3.32 [1.14,9.71; P=0.03], respectively). Presence of a BCG-vaccination scar was associated with a 67% (P=0.03) relative risk reduction for progression to active tuberculosis.These RD1-derived antigens are early targets of cellular immunity following tuberculosis exposure and T-cells specific for these antigens predict progression to active tuberculosis suggesting diagnostic and prognostic utility