Trasplante de homoinjertos valvulares cardiacos y vasculares

The advances in the manipulation of human tissues, the development of cryobiology, paediatric cardiac surgery, the impossibility of obtaining an ideal prosthetic cardiac valve and the surgical treatment of cardiovascular infections have revived interest in the use of homografts. The donors of these homografts can be: a) Live donors: aortic and pulmonary valve of the recipient of a heart transplant; b) Multiorgan donors with a diagnosis of death according to neurological criteria, whose heart is rejected for heart transplant; c) Cadaver donors with asystolia of less than 8 hours. Homograft cardiac valves are the substitute of choice in aortic valve endocarditis, patients with counter-indications for anticoagulation, reconstruction of the outflow tract of the right ventricle, aortic valve replacement in children and young adults through the Ross operation, and an optional indication is the aortic valve and/or rising aorta replacement in patients over 60 years of age. Although there are not sufficiently broad series of homogratfs with arterial substitutes, with respect to the number of patients and time of evolution, the results suggest that this can benefit patients with vascular infection, immunodepressed patients or complex patients whose technique during the operation might require a homograft

Simultaneous control of NOx, soot and fuel economy of a dies engine with dual-loop EGR and VNT using economic MPC

This paper proposes a nonlinear Economic Model Predictive Control (eMPC) strategy for the airpath management of diesel engines with dual-loop Exhaust Gas Recirculation (EGR) and Variable Nozzle Turbocharger (VNT). The controller directly controls the VNT and dual-loop EGR valves to simultaneously minimise NOx, soot and pumping loss. The novelty of this management strategy is to use a merged controller to replace a conventional combination of supervisory and tracking controllers, as well as eliminating the offline determination of the intake manifold pressure and cylinder oxygen concentration set points. The eMPC computes the set points online based on the engine operating condition, state feedback and the weightings of each economic objective, namely NOx, soot and fuel economy. The eMPC is simulated with an experimentally validated EURO 6 2L four-cylinder engine model. The performance of the eMPC is compared to a production controller over the Worldwide harmonised Light vehicles Test Cycles (WLTC). Compared to the production controller, the eMPC demonstrates NOx and soot emission reductions as well as improved torque tracking and fuel economy

T-type calcium channels drive migration/invasion in BRAFV600E melanoma cells through Snail1

Melanoma is a malignant tumor derived from melanocytes. Once disseminated, it is usually highly resistant to chemotherapy and is associated with poor prognosis. We have recently reported that T-type calcium channels (TTCCs) are overexpressed in melanoma cells and play an important role in melanoma progression. Importantly, TTCC pharmacological blockers reduce proliferation and deregulate autophagy leading to apoptosis. Here, we analyze the role of autophagy during migration/invasion of melanoma cells. TTCC Cav3.1 and LC3-II proteins are highly expressed in BRAFV600E compared with NRAS mutant melanomas, both in cell lines and biopsies. Chloroquine, pharmacological blockade, or gene silencing of TTCCs inhibit the autophagic flux and impair the migration and invasion capabilities, specifically in BRAFV600E melanoma cells. Snail1 plays an important role in motility and invasion of melanoma cells. We show that Snail1 is strongly expressed in BRAFV600E melanoma cells and patient biopsies, and its expression decreases when autophagy is blocked. These results demonstrate a role of Snail1 during BRAFV600E melanoma progression and strongly suggest that targeting macroautophagy and, particularly TTCCs, might be a good therapeutic strategy to inhibit metastasis of the most common melanoma type (BRAFV600E)