Testosterone, Endothelial Health, and Erectile Function

Experimental and clinical studies have reported that testosterone has a critical role in the maintenance of homeostatic and morphologic corpus cavernosum components, essential for normal erectile physiology. Although the exact mechanisms mediated by testosterone in erectile function are still under investigation, recent research has suggested an important role in the regulation of endothelial cell (EC) biological functions. Besides stimulating the production of EC mediators, testosterone is also thought to promote the vasculogenic reendothelialization process, mediated by bone marrow-derived endothelial progenitor cells. Additionally, testosterone seems to modulate other erectile tissue components, including trabecular smooth muscle cells, nerve fibers, and tunica albuginea structure, all essential for the erectile process. This paper summarizes current data regarding testosterone-induced cellular and molecular mechanisms that regulate penile tissue components, focusing particularly on the role of testosterone in endothelial health and erectile function

Fault isolation schemes for a class of continuous-time stochastic dynamical systems

In this paper a new method for fault isolation in a class of continuous-time stochastic dynamical systems is proposed. The method is framed in the context of model-based analytical redundancy, consisting in the generation of a residual signal by means of a diagnostic observer, for its posterior analysis. Once a fault has been detected, and assuming some basic a priori knowledge about the set of possible failures in the plant, the isolation task is then formulated as a type of on-line statistical classification problem. The proposed isolation scheme employs in parallel different hypotheses tests on a statistic of the residual signal, one test for each possible fault. This isolation method is characterized by deriving for the unidimensional case, a sufficient isolability condition as well as an upperbound of the probability of missed isolation. Simulation examples illustrate the applicability of the proposed scheme

Detection and Isolation of Simultaneous Additive and Parametric Faults in Nonlinear Stochastic Dynamical Systems

This paper presents a new fault detection and isolation scheme for dealing with simultaneous additive and parametric faults. The new design integrates a system for additive fault detection based on Castillo and Zufiria, 2009 and a new parametric fault detection and isolation scheme inspired in Munz and Zufiria, 2008 . It is shown that the so far existing schemes do not behave correctly when both additive and parametric faults occur simultaneously; to solve the problem a new integrated scheme is proposed. Computer simulation results are presented to confirm the theoretical studies

Property tax as urban planning instrument in large cities: the Brazilian experience

There is an ongoing process of increasing urbanization of the world population with socio-spatial polarization in large cities. Such population density increases the competition for urban land, arousing crescent ground rent generation from the central areas, where there is greater availability of urban infrastructure. The outcome of this process has been an extensive growth of these cities, generating costs for the low-income population, forced to take longer trips to get to work centers. It is also represents a cost increment for public administration, responsible for the expansion of urban infrastructure networks. One among the various instruments to face these costs is the urban real estate taxation, which can also fulfill an extra fiscal function, when used to regulate land use. In this article, we aim to analyze urban policy in Brazil regarding the use of the property taxation instrument, arguing its effectiveness in controlling land use. This was an important innovation introduced by the 1988 Federal Constitution and it is associated with private property defense as long as it fulfills its social function. Under these conditions, the main tax levied on real estate assets in Brazil, the Urban Building and Land Tax (IPTU), would be used as an urban policy instrument by foreseeing the possibility of using different rates according to the land's condition (built or not), its destination (residential or commercial), and also predicting progressive rates for properties that do not comply with the social function. Our study takes as reference municipalities with population over 200,000 inhabitants

Role of oxidative stress-induced systemic and cavernosal molecular alterations in the progression of diabetic erectile dysfunction

Background Erectile dysfunction (ED) is a prevalent complication of diabetes, and oxidative stress is an important feature of diabetic ED. Oxidative stress-induced damage plays a pivotal role in the development of tissue alterations. However, the deleterious effects of oxidative stress in the corpus cavernosum with the progression of diabetes remain unclear. The aim of this study was to evaluate systemic and penile oxidative stress status in the early and late stages of diabetes. Methods Male Wistar streptozotocin-diabetic rats (and age-matched controls) were examined 2 (early) and 8 weeks (late) after the induction of diabetes. Systemic oxidative stress was evaluated by urinary H2O2 and the ratio of circulating reduced/oxidized glutathione (GSH/GSSG). Penile oxidative status was assessed by H2O2 production and 3-nitrotyrosine (3-NT) formation. Cavernosal endothelial nitric oxide synthase (eNOS) was analyzed by quantitative immunohistochemistry. Dual immunofluorescence was also performed for 3-NT and α-smooth muscle actin (α-SMA) and eNOS–α-SMA. Results There was a significant increase in urinary H2O2 levels in both diabetic groups. The plasma GSH/GSSG ratio was significantly augmented in late diabetes. In cavernosal tissue, H2O2 production was significantly increased in late diabetes. Reactivity for 3-NT was located predominantly in cavernosal smooth muscle (SM) and was significantly reduced in late diabetes. Quantitative immunohistochemistry revealed a significant decrease in eNOS levels in cavernosal SM and endothelium in late diabetes. Conclusions The findings indicate that the noxious effects of oxidative stress are more prominent in late diabetes. Increased penile protein oxidative modifications and decreased eNOS expression may be responsible for structural and/or functional deregulation, contributing to the progression of diabetes-associated ED

Variables que condicionan la capacitación continua de graduados en Análisis Clínicos en América Latina

La actualización de los profesionales de la salud latinoamericanos recae en instituciones nacionales e internacionales, universitarias y no universitarias. La capacitación a distancia y presencial en Bioquímica Clínica en América Latina y la investigación en medios y sistemas educativos aplicada a la misma es una tarea que realizamos desde hace 24 años. La estructura formal de los posgrados está bastante bien caracterizada en la región, pero la capacitación profesional o no formal, incluida dentro de la Educación Superior de posgrado, no ha sido abordada en forma sistemática. Los graduados deben tener posibilidades, tanto como los alumnos de grado, de ejercer su derecho a la Educación Superior como una educación a lo largo de toda la vida , como definiera la Declaración de París de 1998 o como un derecho humano y bien público social . Esta comunicación resume algunos de los datos obtenidos en Latinoamérica y son parte de relevamientos planificados para la identificación de variables que determinen las posibilidades y limitaciones respecto al acceso a la capacitación continua de los graduados en bioquímica. Con esta base se prevé diseñar una oferta que canalice la cooperación e intercambio de cursos mediante una red de instituciones latinoamericanas