Autonomous University of Barcelona

About: Autonomous University of Barcelona is a education organization based out in Cerdanyola del Vallès, Spain. It is known for research contribution in the topics: Population & Context (language use). The organization has 37833 authors who have published 80514 publications receiving 2321142 citations. The organization is also known as: Universitat Autònoma de Barcelona & Computer Vision Center.

Encoding amplitude information onto phase-only filters

Abstract: We report a new, to our knowledge, technique for encoding amplitude information onto a phase-only filter with a single liquid-crystal spatial light modulator. In our approach we spatially modulate the phase that is encoded onto the filter and, consequently, spatially modify the diffraction efficiency of the filter. Light that is not diffracted into the first order is sent into the zero order, effectively allowing for amplitude modulation of either the first-order or the zero-order diffracted light. This technique has several applications in both optical pattern recognition and image processing, including amplitude modulation and inverse filters. Experimental results are included for the new technique.

Ligand-specific regulation of the extracellular surface of a G-protein-coupled receptor

Abstract: G-protein-coupled receptors (GPCRs) mediate the majority of cellular responses to hormones and neurotransmitters, and these membrane proteins are the largest group of therapeutic targets for a broad range of diseases. It is very difficult to obtain high-resolution X-ray crystal structures of GPCRs; little is known about the functional role(s) of the extracellular surface in receptor activation or about the conformational coupling of the extracellular surface to the native ligand-binding pocket. In this study, Bokoch et al. used NMR spectroscopy to investigate ligand-specific conformational changes around a salt bridge linking extracellular loops 2 and 3 of the β2 adrenergic receptor. They found that drugs that bind within the transmembrane core (and exhibit different efficacies towards G-protein activation) stabilize distinct conformations of the extracellular surface. New therapeutic agents that target this diverse surface could function as allosteric modulators with high subtype selectivity. G-protein-coupled receptors (GPCRs) mediate the majority of cellular responses to hormones and neurotransmitters and are the largest group of therapeutic targets for a range of diseases. The extracellular surface (ECS) of GPCRs is diverse and therefore an ideal target for the discovery of subtype-selective drugs. Here, NMR spectroscopy is used to investigate ligand-specific conformational changes around a central structural feature in the ECS of a GPCR. G-protein-coupled receptors (GPCRs) are seven-transmembrane proteins that mediate most cellular responses to hormones and neurotransmitters. They are the largest group of therapeutic targets for a broad spectrum of diseases. Recent crystal structures of GPCRs1,2,3,4,5 have revealed structural conservation extending from the orthosteric ligand-binding site in the transmembrane core to the cytoplasmic G-protein-coupling domains. In contrast, the extracellular surface (ECS) of GPCRs is remarkably diverse and is therefore an ideal target for the discovery of subtype-selective drugs. However, little is known about the functional role of the ECS in receptor activation, or about conformational coupling of this surface to the native ligand-binding pocket. Here we use NMR spectroscopy to investigate ligand-specific conformational changes around a central structural feature in the ECS of the β2 adrenergic receptor: a salt bridge linking extracellular loops 2 and 3. Small-molecule drugs that bind within the transmembrane core and exhibit different efficacies towards G-protein activation (agonist, neutral antagonist and inverse agonist) also stabilize distinct conformations of the ECS. We thereby demonstrate conformational coupling between the ECS and the orthosteric binding site, showing that drugs targeting this diverse surface could function as allosteric modulators with high subtype selectivity. Moreover, these studies provide a new insight into the dynamic behaviour of GPCRs not addressable by static, inactive-state crystal structures.

Estimación del riesgo coronario en España mediante la ecuación de Framingham calibrada

Abstract: Introduction and objectives. The Framingham coronary heart disease (CHD) functions overestimate the risk of CHD in countries with a low incidence. Consequently, these functions should be calibrated for the purpose of primary prevention. Calibrated Framingham function charts of overall CHD risk for the Spanish population are presented. Patients and methods. The Framingham functions were calibrated by substituting the prevalence of CHD risk factors and incidence found in Framingham with the same values for Spain. The Framingham function that included high-density lipoprotein (HDL) cholesterol was used. The 10-year probability of developing a CHD event was estimated for several combinations of risk factors and HDL levels ranging from 35 to 59 mg/dl. Color-coded charts were prepared that show the exact probability of CHD corresponding to each combination of risk factors, shown in separate cells on the chart. Results. The event rate and prevalence of CHD risk factors differed considerably between Girona and Framingham. HDL 60 mg/dL reduced it by 50%. The proportion of cells in which the 10-year probability of developing a CHD event was > 9% was 2.3 times higher and that of cells with a probability > 19% was 13 times lower in the chart calibrated for Spain than in the original Framingham charts. Conclusions. The calibrated Framingham function may help to more accurately estimate the overall risk of CHD in the Spanish population for primary prevention purposes. The calibrated function should be validated, and the development of functions for the Spanish population should be promoted.