Search

The Copahue volcano host one of the most attractive geothermal resources of Argentina. Several studies focused on both the volcanic activity and the related geothermal manifestations, including a feasibility report during the ‘90s. However, limited, unclear and usually contradictory structural interpretations are found in the literature, and the role of the main faults over the geothermal system remains thus unsolved. This paper provides the first structural characterization and role assessment of the faults over the fluid flow and the reservoir geometry. A 3D structural model has been constructed to achieve this goal, and a fault-plane striations survey has been carried out at Anfiteatro, Termas and Maquinitas hydrothermal zones. Using this dataset, a slip and dilation tendency analysis over the main structures have been performed. The 3D structural model indicates that the Copahue geothermal field is bounded by an N60°-trending fault set and constrained to the north by the Trolope fault and to the south by the Chancho-Co fault, both with WNW-ESE trend. The collected fault-plain striations data was inverted to obtain the paleostress tensor related to the formation of the Copahue village fault system (CVFS), the structure that controls the hydrothermal areas. The subvertical maximum principal stress axis obtained defines a well constrained tensional regime, with a subhorizontal NW-SE minimum principal stress, consistent in all the surveyed locations. Both the 3D model and the inverted paleostress tensor indicate that the geothermal field, and probably the entire northeastern slope of the volcano, is subjected to an extensional faulting regime. Our analysis shows that the N°60-trending fault set is critically stressed for dilation and probably behaves as an active hydrological fault system, whereas the N105° and N135° fault sets have intermediate and low dilation tendency, respectively. These tendencies might lead to a northeast-trend fluid path between the Chancho-co and the N135° faults and might define the extension of the steam cap. We propose a compartmentalized reservoir model made up by three fault segmented blocks. While a steam cap over a deeper reservoir controlled by the CVFS characterizes the central segment, a pressurized liquid-dominated reservoir could prevail to the west of Termas and the east of Maquinas hydrothermal zones. This model explains the differences between the fumaroles inside the CVFS (i.e., Termas to Maquinas fumaroles) and outside this structural system (i.e., Anfiteatro), is consistent with the steam cap identified by the exploration boreholes and is consistent with the 3D structural framework proposed. Also, the model suggests that the collapse of the eastern slope of the Chancho-co hill might constitute the initial state of the current configuration of the geothermal system. Additional studies are needed to verify the proposed reservoir model before defining deep exploration targets, including magnetotellurics, discrete fracture network analysis, and preliminary thermodynamical models. Fil: Barcelona, Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina Fil: Yagupsky, Daniel Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina Fil: Vigide, Nicolás Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina Fil: Senger, Martín Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas; Argentina

Resumen Introducción: los aneurismas micóticos son una entidad grave y poco frecuente, cuyo tratamiento quirúrgico se ha basado históricamente en la resección del tejido infectado y en la reconstrucción arterial. En los últimos años, la importancia del uso de técnicas de reparación endovascular ha ido en aumento. Caso clínico: se presenta el caso de una mujer de 84 años con un aneurisma micótico de la aorta visceral tratado mediante un abordaje híbrido. Se revascularizan las arterias mesentérica superior y hepática y, posteriormente, se coloca una endoprótesis de aorta. Discusión: el empleo de dispositivos endovasculares para la reparación de los aneurismas micóticos genera controversia debido a que no se elimina el tejido infectado. Sin embargo, existen publicaciones que avalan su uso, ya que permiten el tratamiento, principalmente, de pacientes de alto riesgo quirúrgico sin aumentar el número de complicaciones.

Resumen Introducción: los schwannomas, también llamados neurilemomas o neurinomas, son tumores de origen neuroectodérmico, encapsulados y benignos, que generalmente aparecen como una masa laterocervical asintomática de crecimiento lento. Son pocos frecuentes en el área de cabeza y cuello. Caso clínico: mujer de 39 años con una historia de un año de evolución de una masa cervical derecha de crecimiento lento, pulsátil, dolorosa y móvil en el lado derecho del cuello. La imagen de la angiotomografía computarizada preoperatoria demostró que la masa involucraba la bifurcación carotídea, compatible con un paraganglioma carotídeo. La disección cuidadosa a través de una cervicotomía longitudinal mostró que la masa surgía de un único fascículo del nervio vago. La masa se envió a anatomía patológica con el resultado de schwannoma. En el posoperatorio la paciente presentó una función sensorial y motora del vago normal, con un leve síndrome de Horner. Discusión: los tumores nerviosos del cuello surgen a partir de grandes troncos nerviosos, los IX, X, XI y XII pares craneales, el simpático cervical, el plexo cervical y el plexo braquial. El nervio vago es un lugar infrecuente de aparición, con muy pocos casos reportados. Son lesiones de diagnóstico preoperatorio difícil, cuyo tratamiento de elección es la exéresis quirúrgica; en ocasiones, es difícil conservar el nervio de origen.

The proteasomal degradation system is one of the most important protein degradation systems in the cytosol and nucleus. This system is present in two major forms: the ATP-stimulated 26S/30 S proteasome or the ATP-independent 20S core proteasome. While the first recognize ubiquitin-tagged target proteins and degrade them, the 20S proteasome works also independent from ATP, but requires partially unfolded substrates. While the role of the proteasome in the selective removal of oxidized proteins is undoubted, the debate about a selective ubiquitination of oxidized proteins is still ongoing. Here we demonstrate, that under some conditions of oxidative stress an accumulation of oxidized and of K48-ubiquitinated proteins occurs. However, the removal of oxidized proteins seems not to be linked to ubiquitination. In further experiments, we could show that the accumulation of ubiquitinated proteins under certain oxidative stress conditions is rather a result of a different sensitivity of the 26S proteasome and the ubiquitination machinery towards oxidants.

Urolithin A is a metabolite generated from ellagic acid and ellagitannins by the intestinal microbiota after consumption of fruits such as pomegranates or strawberries. The objective of this study was to determine the cytoprotective capacity of this polyphenol in Neuro-2a cells subjected to oxidative stress, as well as its direct radical scavenging activity and properties as an inhibitor of oxidases. Cells treated with this compound and H2O2 showed a greater response to oxidative stress than cells only treated with H2O2, as mitochondrial activity (MTT assay), redox state (ROS formation, lipid peroxidation), and the activity of antioxidant enzymes (CAT: catalase, SOD: superoxide dismutase, GR: glutathione reductase, GPx: glutathione peroxidase) were significantly ameliorated, additionally, urolithin A enhanced the expression of cytoprotective peroxiredoxins 1 and 3. Urolithin A also acted as a direct radical scavenger, showing values of 13.2 &mu, M Trolox Equivalents for Oxygen Radical Absorbance Capacity (ORAC) and 5.01 &micro, M and 152.66 &micro, M IC50 values for superoxide and 2,2-diphenyss1-picrylhydrazyl (DPPH) radicals, respectively. Finally, inhibition of oxidizing enzymes, such as monoamine oxidase A and tyrosinase, was also detected in a dose-dependent manner. The cytoprotective effects of urolithin A could be attributed to the improvement of the cellular antioxidant battery, but also to its role as a direct radical scavenger and enzyme inhibitor of oxidases.

The production of reactive species is an inevitable by-product of metabolism and thus, life itself. Since reactive species are able to damage cellular structures, especially proteins, as the most abundant macromolecule of mammalian cells, systems are necessary which regulate and preserve a functional cellular protein pool, in a process termed “proteostasis”. Not only the mammalian protein pool is subject of a constant turnover, organelles are also degraded and rebuild. The most important systems for these removal processes are the “ubiquitin-proteasomal system” (UPS), the central proteolytic machinery of mammalian cells, mainly responsible for proteostasis, as well as the “autophagy-lysosomal system”, which mediates the turnover of organelles and large aggregates. Many age-related pathologies and the aging process itself are accompanied by a dysregulation of UPS, autophagy and the cross-talk between both systems. This review will describe the sources and effects of oxidative stress, preservation of cellular protein- and organelle-homeostasis and the effects of aging on proteostasis in mammalian cells., Graphical abstract fx1

Mitochondria have been in the focus of oxidative stress and aging research for decades due to their permanent production of ROS during the oxidative phosphorylation. The hypothesis exists that mitochondria are involved in the formation of lipofuscin, an autofluorescent protein aggregate that accumulates progressively over time in lysosomes of post-mitotic and senescent cells. To investigate the influence and involvement of mitochondria in lipofuscinogenesis, we analyzed lipofuscin amounts as well as the mitochondrial function in young and senescent cells. In addition we used an aging model and Lon protease deficient HeLa cells to investigate the influence of mitochondrial degradation processes on lipofuscin formation.We were able to show that mitophagy is impaired in senescent cells resulting in an increased mitochondrial mass and superoxide formation. In addition, the inhibition of mitochondrial fission leads to increased lipofuscin formation.Moreover, we observed that Lon protease downregulation is linked to a higher lipofuscinogenesis whereas the application of the mitochondrial-targeted antioxidant mitoTEMPO is able to prevent the accumulation of this protein aggregate. Keywords: Lipofuscin, Protein aggregates, Lon protease, Aging, Mitochondria, Oxidative stress

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are hepatic manifestations of the metabolic syndrome. Many currently used animal models of NAFLD/NASH lack clinical features of either NASH or metabolic syndrome such as hepatic inflammation and fibrosis (e.g., high-fat diets) or overweight and insulin resistance (e.g., methionine-choline-deficient diets), or they are based on monogenetic defects (e.g., ob/ob mice). In the current study, a Western-type diet containing soybean oil with high n-6-PUFA and 0.75% cholesterol (SOD + Cho) induced steatosis, inflammation and fibrosis accompanied by hepatic lipid peroxidation and oxidative stress in livers of C57BL/6-mice, which in addition showed increased weight gain and insulin resistance, thus displaying a phenotype closely resembling all clinical features of NASH in patients with metabolic syndrome. In striking contrast, a soybean oil-containing Western-type diet without cholesterol (SOD) induced only mild steatosis but not hepatic inflammation, fibrosis, weight gain or insulin resistance. Another high-fat diet, mainly consisting of lard and supplemented with fructose in drinking water (LAD + Fru), resulted in more prominent weight gain, insulin resistance and hepatic steatosis than SOD + Cho, but livers were devoid of inflammation and fibrosis. Although both LAD + Fru- and SOD + Cho-fed animals had high plasma cholesterol, liver cholesterol was elevated only in SOD + Cho animals. Cholesterol induced expression of chemotactic and inflammatory cytokines in cultured Kupffer cells and rendered hepatocytes more susceptible to apoptosis. In summary, dietary cholesterol in the SOD + Cho diet may trigger hepatic inflammation and fibrosis. SOD + Cho-fed animals may be a useful disease model displaying many clinical features of patients with the metabolic syndrome and NASH.

[ES] Con este proyecto, se pretende desarrollar un plan de viabilidad para la empresa denominada ¿Global view¿, la cual se dedicará dentro de el ámbito académico a la creación de un titulo de posgrado en emprendimiento para alumnos que hayan acabado un titulo universitario. Dicho titulo se desarrollará de un modo singular, ya que el titulo se impartirá en un autobús por distintos lugares de Europa. Como se trata de un titulo de emprendimiento es necesario establecer que existe igualdad entre la parte teórica, como la práctica dentro del aprendizaje. Por ello, se utilizarán las horas de trayecto para realizar las clases teóricas, para luego profundizar y afianzar dichos conocimientos de forma práctica a través de la realización de distintas actividades y prácticas dentro de empresas en los distintos lugares que se visitarán por Europa. La realización del título durará 43 días desde su comienzo. El objetivo del proyecto es que los alumnos obtengan los conocimientos y los contactos necesarios para comenzar a emprender, y vivan una experiencia única en la vida. Para ello se realizará, el plan de viabilidad que contendrá un plan marketing, plan estratégico y el plan financiero con el objetivo de analizar si el proyecto es factible o no.