L'Envelliment, aproximació a un procés complex i heterogeni

L'envelliment és un procés complex i heterogeni, no tots envellim de la mateixa manera. En els últims anys s'han incorporat nous conceptes clínics i biològics que poden arribar a qüestionar la natura fisiològica del procés. En aquest capítol es defineix el procés i la seva repercussió en la nostra societat, s'incorporen conceptes com ara la fragilitat, la comorbiditat o la discapacitat, que permeten entendre millor i més bé les repercussions de l'envelliment sobre el nostre organisme, i s'analitzen les peculiaritats dels que envelleixen de manera satisfactòria i arriben a centenaris. Es discuteix el concepte anti-aging des d'una vessant científica i analitzant altres connotacions del concepte. Finalment, s'intenta relacionar l'envelliment del sistema immunitari (immunosenescència) amb algunes malalties autoimmunitàries sistèmiques com ara l'esclerodèrmia i l'arteritis de cèŀlules gegants, i es comenta la progèria i les síndromes progeroides com a models d'estudi de l'envelliment.Aging is a complex and heterogeneous process, with relevant differences between subjects. Conceptual, clinic and biological concepts which can challenge the physiologic nature of aging have been incorporated during the last years. In this chapter a proper definition of aging and the social repercussion of the phenomenon is established, and new concepts such as fragility, comorbidity and discapacity which allow a better understanding of aging and related pathology are described. Centenarians and its rationale is also discussed and analyzed, along with the anti-aging phenomenon and its repercussions on agining. Lastly, a possible relationship between some autoimmune systemic diseases such as systemic sclerosis and giant cell vasculitis (Horton’s disease) and immunosenescence, and also the progeroid syndromes as a model of aging are addressed

Análisis estructural y criterios de diseño de depósitos cilíndricos de hormigón pretensado

The present work is based on the structural behaviour of circular prestressed concrete tanks. In this study, an analytical linear elastic model that considers the soil-tank interaction under axisymmetric loads, taking into account the movement capacity of the wall-to-base connection, is developed. Parametric studies are carried out in order to find the effects on the wall of all parameters governing the stiffness of the wall-to-base connection. Different methods to analyse the main forces of a circular prestressed concrete wall with free edge at the top and a generic wall-to-base connection are presented, which generalize some simplified methods conventionally adopted. A procedure for the determination of a circumferential prestressing function is suggested, in order to ensure a suitable residual compressive stress in the circumferential direction when the tank is full. Furthermore, some criteria about the design of the wall-to-base connection are proposed, taking into account both the tank geometry and the prestressing criteria.Escuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos de la Universidad Politécnica de Catalunya El presente trabajo se centra en el estudio del comportamiento estructural de los depósitos cilíndricos de hormigón pretensado. Los objetivos perseguidos son, por una parte, el desarrollo de un modelo de análisis conjunto de la estructura (pared-solera-cimentación) capaz de caracterizar con rigor la rigidez de la unión entre la pared y la solera. Por otra parte, y en base a múltiples estudios paramétricos realizados con un programa desarrollado a partir del mencionado modelo, se presentan diferentes métodos de cálculo de los esfuerzos de la pared, para una unión genérica en la base, que generalizan otros métodos simplificados usuales en la literatura técnica; se proponen funciones de pretensado que definen la distribución y la fuerza de pretensado adecuadas para mantener comprimida circunferencialmente la pared cuando el depósito está solicitado por el empuje hidrostático, con una tensión mínima de compresión circunferencial exigida en proyecto; y, por último, se proponen criterios para definir el tipo de unión más conveniente en la base, en función de la geometría del depósito y de los criterios de diseño del pretensado

Efficacy and safety of lenalidomide for refractory cutaneous lupus erythematosus

Introduction: Cutaneous lupus erythematosus (CLE) is a chronic disease characterized by disfigurement and a relapsing course. Thalidomide has proven its efficacy in refractory cutaneous lupus disease, although it is not exempt from significant side effects and frequent relapses after withdrawal. New thalidomide analogues have been developed but lack clinical experience. The aim of this preliminary phase II study was to evaluate the efficacy and safety of lenalidomide in patients with refractory CLE. Methods: Fifteen patients with refractory cutaneous lupus disease were enrolled in this single-center, open-label, non-comparative pilot trial between January 2009 and December 2010. Oral lenalidomide (5 to 10 mg/day) was administered and tapered according to clinical response. Patients were followed up for a mean of 15 months (range: 7 to 30). Primary efficacy endpoint was the proportion of patients achieving complete response, defined by a Cutaneous Lupus Erythematosus Disease Area and Severity index (CLASI) activity score of 0. Other secondary endpoints included development of side effects, evaluation of cutaneous and systemic flares, and impact on the immunological parameters.Results: One patient discontinued treatment due to side effects. All remaining patients saw clinical improvement and this was already noticeable after 2 weeks of treatment. Twelve of those patients (86%) achieved complete response but clinical relapse was frequent (75%), usually occurring 2 to 8 weeks after lenalidomide's withdrawal. No influence on systemic disease, immunological parameters or CLASI damage score was observed. Side effects including insomnia, grade 2 neutropenia and gastrointestinal symptoms, were minor (13%). These resolved after withdrawing medication. Neither polyneuropathy nor thrombosis was observed. Conclusion: Lenalidomide appears to be efficacious and safe in patients with refractory CLE, but clinical relapse is frequent after its withdrawal