1119-99 Immunoglobulin A anticardiolipin antibodies are markers of the extent of daily life ischemia in patients with stable angina

Rising population numbers place ever increasing demands on energy resources. A large percentage of the worldwide energy production is reserved for the generation of electricity and a significant portion of the electrical energy generation is used for illumination purposes. At the same time, people demand brighter light sources that provide better light quality. The luminaire of today is not just a simple lamp, but a complex, intelligent piece of technology designed for a specific purpose. This doctoral dissertation aims to provide a link between the theoretical universe surrounding the physics of electromagnetic radiation and the practical illumination world. A theoretical framework presents the physical properties of light and connects, through the human visual system, to a number of perceptual models. Based on these perceptual models, the colourimetric qualities of an illumination spectrum are analysed and a theoretical framework that aims to optimise the balance between colour fidelity and energy efficiency is proposed. The result of this optimisation is a spectrum that needs to be implemented into a light source. Recent advancements in semiconductor technology led to the development of highly efficient light emitting diodes. The monochromatic nature of these light sources offers the possibility of creating a spectrally tuneable luminaire that is able to reproduce these optimised illumination spectra. A fully integrated spectrally tuneable light engine combines knowledge on characterising and driving LEDs, optical design and thermal management. Each group of monochromatic LEDs needs a variable current source that ensures predictable behaviour regardless of their dimming level or temperature. An advanced optical solution enables efficient light extraction from the LEDs, provides excellent luminance and chroma homogenisation and, finally, delivers a suitable beam pattern for the intended illumination application. Proper thermal management establishes sufficient heat extraction to guarantee low semiconductor temperatures. Finally, the LED light engines created during this doctoral research are incorporated into three spectrally tuneable illumination devices, each designed for a specific purpose. A set of spectrally tuneable downlights installed in the laboratories of the lighting group of the Catalonia Institute for Energy Research (IREC) in Barcelona, Spain and the department of neuroscience of the University of Newcastle in the United Kingdom serves as a valuable tool for experiments that evaluate both physical and psychovisual properties of selected illumination spectra. A compact spotlight, used during the "Making Colour" exhibition of the National Gallery in London, is optimised to provide a set of specific illumination spectra to illuminate art reproductions. Lastly, a high power luminaire was designed to generate specialised spectra to irradiate greenhouse plants, steering their morphology and the production of plant-specific compounds.El incremento de población mundial en los últimos años implica necesariamente un incremento en la demanda energética global. Un alto porcentaje de la energía producida globalmente es utilizada para iluminar los diferentes espacios. Al mismo tiempo, los usuarios reclaman cada vez fuentes de luz más potentes y entornos más iluminados y con mayor calidad de luz. Las luminarias actuales no son simplemente lámparas, sino sistemas complejos e inteligentes diseñados con propósitos específicos. Esta tesis doctoral pretende unir dos espacios que normalmente son abordados de manera separada: por un lado, el entorno teórico de la radiación visible y sus propiedades colorimétricas, y por otro lado la luminotecnia aplicada. En el ámbito teórico, se han tratado con las propiedades físicas de la luz, estableciendo un puente a través de la visión humana con diferentes modelos de percepción visual. En base a estos modelos, se han analizado las propiedades colorimétricas de los espectros de iluminación estudiados y se propone un marco teórico de optimización entre fidelidad de color y eficiencia energética. Los resultados de esta optimización se han implementado también en una fuente de luz de espectro modulable real. Recientemente, el mercado LED está alcanzando valores altísimos en cuanto a eficacias lumínicas. Sin embargo, el crecimiento del mercado pasa por mejorar otros aspectos que garanticen el progreso de la tecnología. La naturaleza esencialmente monocromática de los LEDs de estado sólido ofrece la posibilidad de crear fuentes de luz de espectro sintonizable mediante la composición espectral o adición cromática de varios tipos diferentes de LED. Para el diseño de una de estas fuentes de luz se requieren conocimientos en cuanto a la caracterización y energizado de los LEDs, diseño óptico y diseño térmico. Cada clúster de LEDs de características espectrales similares necesita una fuente de corriente variable que garantice unos valores estables y que no dependan de otros parámetros como la potencia de entrada o la temperatura. Se necesitan también soluciones ópticas avanzadas para conseguir no solo una alta eficiencia de extracción de la radiación sino también una mezcla homogénea de los colores a la salida así como una distribución angular específicamente diseñada para cada aplicación. Por otro lado, se precisa de un manejo térmico óptimo que permita la extracción de calor hacia elementos activos o pasivos para que así la temperatura de la unión de los LEDs sea óptima. Finalmente, los módulos LED creados durante esta tesis doctoral se han incorporado en tres luminarias distintas representativas de tres campos de aplicación independientes. La primera aplicación implicó el diseño y la incorporación de los módulos LED a un grupo de downlights que se instalaron en una habitación del Instituto de Investigación en Energía de Cataluña y en el Instituto de Neurociencia de la Universidad de Newcastle (UK), constituyendo dos instalaciones únicas para la investigación de los aspectos físicos y físico-visuales de diferentes espectros de iluminación. Para la segunda aplicación, se diseñaron un conjunto de luminarias tipo spotlight que fueron instaladas y demostradas en la exhibición "Making Colour" que tuvo lugar en la National Gallery (Londres). En la misma, se mostraron las propiedades de distintos espectros de iluminación. Finalmente, se ha realizado también una luminaria de alta potencia optimizada para la generación de espectros de interés en horticultura, habiéndose demostrado que es posible cambiar la morfología de los cultivos estudiados e incentivar la producción de ciertas vitaminas y compuesto

Interrelated modulation of endothelial function in Behcet's disease by clinical activity and corticosteroid treatment

Corticosteroids are commonly used in empirical treatment of Behçet's disease (BD), a systemic inflammatory condition associated with reversible endothelial dysfunction. In the present study we aimed to dissect the effects of clinical disease activity and chronic or short-term corticosteroid treatment on endothelial function in patients with BD. In a case-control, cross-sectional study, we assessed endothelial function by endothelium dependent flow mediated dilatation (FMD) at the brachial artery of 87 patients, who either were or were not receiving chronic corticosteroid treatment, and exhibiting variable clinical disease activity. Healthy individuals matched for age and sex served as controls. Endothelial function was also assessed in a prospective study of 11 patients before and after 7 days of treatment with prednisolone given at disease relapse (20 mg/day). In the cross-sectional component of the study, FMD was lower in patients than in control individuals (mean ± standard error: 4.1 ± 0.4% versus 5.7 ± 0.2%, P = 0.003), whereas there was a significant interaction between the effects of corticosteroids and disease activity on endothelial function (P = 0.014, two-factor analysis of variance). Among patients with inactive BD, those who were not treated with corticosteroids (n = 33) had FMD comparable to that in healthy control individuals, whereas those treated with corticosteroids (n = 15) had impaired endothelial function (P = 0.023 versus the respective control subgroup). In contrast, among patients with active BD, those who were not treated with corticosteroids (n = 20) had lower FMD than control individuals (P = 0.007), but in those who were receiving corticosteroids (n = 19) the FMD values were comparable to those in control individuals. Moreover, FMD was significantly improved after 7 days of prednisolone administration (3.7 ± 0.9% versus 7.6 ± 1.4%, P = 0.027). Taken together, these results imply that although corticosteroid treatment may impair endothelial function per se during the remission phase of the inflammatory process, it restores endothelial dysfunction during active BD by counteracting the harmful effects of relapsing inflammation

Subclinical peripheral arterial disease in rheumatoid arthritis

Objective : Rheumatoid arthritis (RA) is associated with accelerated atherosclerosis in the carotid arteries, but little is known about the magnitude of this process in peripheral arteries. Assessing preclinical atherosclerosis in both arterial beds in RA might provide additional prognostic value during risk stratification for primary prevention. Therefore in the present structural study we examined femoral versus carotid subclinical atherosclerosis in RA and controls. Methods : Intima-media thickness (IMT) and atheromatous plaque presence and vulnerability in femoral versus carotid arteries were examined in 80 RA patients without overt cardiovascular disease or diabetes and 80 controls matched 1:1 for age, gender and traditional cardiovascular disease risk factors. Results : Femoral IMT and plaque prevalence were increased in RA than controls (p=0.001 and 0.008, respectively). These increases remained significant after adjustment for potentially confounding factors that differed between groups, such as C-reactive protein and HDL-cholesterol serum levels, and statin use. Femoral plaque vulnerability did not differ between RA and controls. The presence of RA was found to be an independent predictor of increased femoral IMT (p=0.004), after adjustment for traditional cardiovascular risk factors, C-reactive protein and treatment with angiotensin converting enzyme inhibitors and statins. Femoral plaques were less frequent than carotid plaques in RA patients (22.5% vs 45.0% respectively, p=0.003) and in contrast to carotid plaques were independent of age and glucose levels. Conclusions : Subclinical peripheral atherosclerosis in RA is more advanced than in controls. Prospective studies are required to confirm that RA is an independent risk factor for peripheral arterial disease. (C) 2010 Elsevier Ireland Ltd. All rights reserved