Uretroplastia de sustitución con doble injerto de mucosa oral como opción terapéutica para pacientes con estenosis de uretra bulbar asociada a UroLume®

ResumenEl UroLume® o endoprótesis uretral fue concebido como un dispositivo de fácil colocación para pacientes con estenosis uretral bulbar recurrente. Con el paso del tiempo se demostró que ocasionaba más complicaciones que beneficios por lo que se abandonó su uso. Sin embargo, se generó un grupo de pacientes con estenosis uretral compleja que necesitaban múltiples tratamientos quirúrgicos con resultados poco favorecedores. Con la divulgación a finales de la década de los 90 del uso de injertos de mucosa oral para el tratamiento de estenosis uretral se inició una nueva etapa en la búsqueda de un tratamiento definitivo para este tipo de pacientes. El objetivo del artículo es presentar una técnica quirúrgica no descrita en la literatura para el tratamiento de estenosis uretral bulbar asociada a UroLume®. Se describe el caso de un paciente masculino de 71 años de edad con estenosis uretral bulbar secundaria a resección transuretral de próstata al cual le fue colocado un UroLume® hace 8 años presentando reestenosis uretral, tratado con múltiples dilataciones uretrales. Mediante un abordaje perineal se retiró la endoprótesis en su totalidad, en base a las características locales de los tejidos se decidió colocar un doble injerto de mucosa oral dorsal inlay y ventral onlay con resultados exitosos a 6 meses de seguimiento.AbstractUroLume®, or urethral endoprosthesis, was conceived as an easy placement device for patients with recurrent bulbar urethral stricture. With the passage of time, it was shown to cause more complications than benefits and its use was discontinued. However, it created a group of patients with complex urethral stricture that required multiple surgical treatments with unsatisfactory results. The widespread use at the end of the 1990s of buccal mucosa grafts for the treatment of urethral stricture began a new stage in the search for a definitive treatment for this type of patient.The aim of our article was to present a surgical technique for the treatment of UroLume®-associated bulbar urethral stricture that has not been described in the literature.A 71-year-old man presented with bulbar urethral stricture secondary to transurethral resection of the prostate who, 8 years ago, had UroLume® placement. He presented with another urethral stricture and was treated with numerous urethral dilations. Through the perineal approach, the endoprosthesis was completely removed, and based on the local tissue characteristics, a dorsal inlay and ventral onlay double buccal mucosa graft was placed with successful results at the 6th month of follow-up

Sismicidad de la Precordillera Sanjuanina entre 29ºS y 32ºS: análisis de fuente sísmica y del campo de esfuerzos

En el presente estudio se analiza la sismicidad cortical (< 65 km) registrada en la Precordillera Sanjuanina durante 2008 y 2009 por 52 estaciones sismológicas temporales de banda ancha distribuidas en Cordillera, Precordillera, Sierras Pampeanas Orientales y Occidentales. Para este sector del retroarco andino se localizaron un total de 100 sismos corticales con profundidades focales < 65 km y sus correspondientes mecanismos focales. Los sismos localizados en Precordillera presentan magnitudes 0,4<ML<5,3 y 1,3<MW<5,3. El estudio de localización sísmica utilizando un modelo de velocidades mejorado permitió obtener profundidades focales comprendidades entre 5 km y 46 km de profundidad. El análisis de mecanismos focales utilizando primeros arribos indica mayor proporción de soluciones de fallamiento inverso o inverso con pequeña componente de rumbo y en menor abundancia mecanismos normales o conteniendo alguna componente de rumbo. El campo de esfuerzos obtenido sobre 100 sismos corticales claramente indica una componente del eje mayor compresivo orientado en dirección este-oeste. Estos resultados son consistentes con la tectónica compresiva de la Precordillera para niveles de corteza media a superior.Eje: Estudio del Interior Terrestre.Facultad de Ciencias Astronómicas y Geofísica

Hybridization between I-type and S-type granites in the Ordovician Famatinian magmatic arc, Tafí del Valle, Tucumán, NW Argentina

In the Tafí del Valle region, in northwestern Argentina, several intrusive bodies of lower Paleozoic age are emplaced in a low to medium metamorphic grade basement, owing to the Sierras Pampeanas. The plutonic complexes called El Infiernillo, La Ovejería, Loma Pelada and Los Cuartos have been previously included in regional descriptive compilations. In this study, new trace element analyses of these intrusive granitoids are presented and added to the geochemical background in order to constrain the main petrological and geochemical characteristics of the lower Paleozoic magmatism in the Tafí del Valle region. Most of the studied intrusive granitoids show calc-alkaline geochemical signatures and are moderately to strongly peraluminous. They can be grouped into three main groups: 1) La Ovejería and El Infiernillo samples present cotectic evolutions that match those trends traced for Cpx + Pl fractionation and similar to the regional calc-alkaline systems used for comparison, at least in the less evolved tonalites and granodiorites. 2) A second group is composed of some granitoids from Loma Pelada and Los Cuartos plutons, which present very evolved compositions with low percentage of CaO and MgO. These granitoids are placed in the compositional range of S type magmas described in the region, trending to the location of the host rocks with increasing peraluminosity. 3) The third group is comprised by the samples of Loma Pelada and Los Cuartos intrusive units that show intermediate geochemical characteristics between the granitoids from El Infiernillo and La Ovejería and the regional metasedimentary rocks. These could be explained by mingling or mixing of magmas with different geochemical signatures, or by an assimilation process that involves a large contribution of metasedimentary material to the calc-alkaline intrusive magmas

Comportamiento sísmico de edificaciones de tapia pisada reforzadas con marcos de madera y viga de coronación en concreto

Earth construction is present all over the world. Many of these constructions are in seismic regions and have a high seismic vulnerability. To reduce this vulnerability and prevent collapse this paper proposes an integrated strategy consisting in an external reinforcement with wooden elements in both directions and on both sides of the walls (rammed earth) and a rigid diaphragm by means of an upper concrete beam. This beam is proposed to be built with a smooth transition between the earth and the concrete to improve compatibility. The results of shake table tests on a 1:6 scaled model and its unreinforced counterpart show a significant improvement in the global behaviour of the construction (The results of the tests showed a reduction in the displacements up to 80% in the reinforced models), achieving the main objective of preventing collapse while the structure remains almost intact.La construcción en tierra está presente en todo el mundo. Muchas de estas construcciones se encuentran en regiones sísmicas y tienen una vulnerabilidad alta. Con el fin de reducir esta vulnerabilidad se propone una estrategia integrada que consiste en un refuerzo externo con elementos de madera en ambas direcciones y en ambos lados de los muros (en tapia pisada) simultáneamente con la implementación de un diafragma rígido por medio de una viga de coronación en concreto. Se propone que la viga se construya con una transición entre la tierra y el concreto para mejorar la compatibilidad. Los resultados de ensayos en mesa vibratoria en un modelo a escala 1:6 y su contraparte no reforzada muestran una mejora significativa en el comportamiento global de la construcción (reducción en los desplazamientos hasta del 80% en los modelos reforzados), logrando el objetivo de prevenir el colapso, manteniendo la integridad de la estructura

Magnetism of small V clusters embedded in a Cu fcc matrix: an ab initio study

We present extensive first principles density functional theory (DFT) calculations dedicated to analyze the magnetic and electronic properties of small V$_{n}$ clusters (n=1,2,3,4,5,6) embedded in a Cu fcc matrix. We consider different cluster structures such as: i) a single V impurity, ii) several V$_{2}$ dimers having different interatomic distance and varying local atomic environment, iii) V$_{3}$ and iv) V$_{4}$ clusters for which we assume compact as well as 2- and 1-dimensional atomic configurations and finally, in the case of the v) V$_{5}$ and vi) V$_{6}$ structures we consider a square pyramid and a square bipyramid together with linear arrays, respectively. In all cases, the V atoms are embedded as substitutional impurities in the Cu network. In general, and as in the free standing case, we have found that the V clusters tend to form compact atomic arrays within the cooper matrix. Our calculated non spin-polarized density of states at the V sites shows a complex peaked structure around the Fermi level that strongly changes as a function of both the interatomic distance and local atomic environment, a result that anticipates a non trivial magnetic behavior. In fact, our DFT calculations reveal, in each one of our clusters systems, the existence of different magnetic solutions (ferromagnetic, ferrimagnetic, and antiferromagnetic) with very small energy differences among them, a result that could lead to the existence of complex finite-temperature magnetic properties. Finally, we compare our results with recent experimental measurements.Comment: 7 pages and 4 figure

Oxidative Stress and Parkinson’s Disease: Effects on Environmental Toxicology

Epidemiological studies have found an increased risk of Parkinson’s disease (PD) with environmental factors such as exposure to substances derived from industrial processes, use of agrochemicals, or living in a rural environment. The hypothesis that certain environmental toxins could be the source of the EP is supported by the discovery that chemicals such as herbicides paraquat, diquat, and the fungicide maneb are selectively toxic in nigrostriatal dopaminergic neurons. Also, one of the insecticides produced by plants, such as rotenone, and by-product of the synthesis of synthetic heroin MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) can be reproduced in animal models where neurochemicals, histopathological, and clinical characteristic of PD can be found. Interestingly, there are similarities in the chemical structure of paraquat and MPTP. Recent evidence exhibited that inflammation and oxidative stress play an essential role in the development of PD. So, in our laboratory we found that in an animal model melatonin decreases the products of lipid oxidation, nitric oxide metabolites, and the activity of cyclooxygenase 2, which are induced by an intraperitoneal injection of MPTP. This suggests that the neuroprotective effects of melatonin are partially attributed to its antioxidant scavenging and anti-inflammatory action

Physiology and Pathology of Neuroimmunology: Role of Inflammation in Parkinson’s Disease

Parkinson’s disease (PD) is a neurodegenerative disease that affects 1% of the population aged 65 and over and is the second most common neurodegenerative disease next to Alzheimer’s disease. Interneuronal proteinaceous inclusions called Lewy bodies (LB) and a selective degeneration of dopaminergic neurons of the substantia nigra pars compacta (SNPC) are the main features of PD pathology. The most common clinical manifestations are rigidity, tremor, bradykinesia, postural instability, sleep disorders, alterations in gait, smell, memory, and dementia. Genetic and environmental factors are involved in PD, and, recently, oxidative stress, proteasome-mediated protein degradation, and inflammation have acquired relevance as major mechanisms of neuronal dysfunction. Increased levels of reactive oxygen and nitrogen species in the brain contribute to greater vulnerability of proteins to nitro-oxidative modification and to greater degrees of aggregation. These protein aggregates contain a variety of proteins of which α-synuclein appears to be the main structural component. Interestingly, α-synuclein can be secreted by neuronal cells and may lead the initiation and the maintenance of inflammatory events through the activation of microglia, which contributes to dopaminergic neuron depletion. New evidence also suggests that PD may be the result of an autoimmune response in which the immune cells recognize the neurons as foreign elements and would act against them, causing their death

Multiple Sclerosis and Its Relationship with Oxidative Stress, Glutathione Redox System, ATPase System, and Membrane Fluidity

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) with a focus on inflammation, demyelination, and damage to axons leading to neurological deficits. MS pathology is associated with excessive reactive oxygen species (ROS) and generation of reactive nitrogen species (RNS), causing oxidative/nitrosative stress. Deregulation of glutathione homeostasis and alterations in glutathione‐dependent enzymes are implicated in MS. Reactive oxygen species enhance both monocyte adhesion and migration across brain endothelial cells. In addition, ROS can activate the expression of the nuclear transcription factor‐kappa, which upregulates the expression of many genes involved in MS, such as tumor necrosis factor‐α and nitric oxide synthase, among others, leading to mitochondrial dysfunction and energy deficits that result in mitochondrial and cellular calcium overload. Loss of mitochondrial membrane potential can increase the release of cytochrome c, one pathway that leads to neuronal apoptosis. Clinical studies suggest that omega‐3 long‐chain polyunsaturated fatty acids (PUFAs) including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have anti‐inflammatory, antioxidant, and neuroprotective effects in MS and animal models of MS. Here, we review the relationship of oxidative stress, the glutathione redox system, the ATPase system, and membrane fluidity with the development of MS. In addition, we describe the main findings of a clinical trial conducted with relapsing‐remitting MS patients who received a diet supplemented with 4 g/day of fish oil or olive oil. The effects of PUFAs supplementation on the parameters indicated above are analyzed in this work

African Mountain Thistles: Three New Genera in the Carduus-Cirsium Group

The floras on the highest mountains in tropical eastern Africa are among the most unique floras in the world. Despite the exceptionally high concentration of endemic species, these floras remain understudied from an evolutionary point of view. In this study, we focus on the Carduus-Cirsium group (subtribe Carduinae) to unravel the evolutionary relationships of the species endemic to the tropical Afromontane and Afroalpine floras, aiming to improve the systematics of the group. We applied the Hyb-Seq approach using the Compositae1061 probe set on 190 samples (159 species), encompassing representatives of all genera of Carduinae. We used two recently developed pipelines that enabled the processing of raw sequence reads, identification of paralogous sequences and segregation into orthologous alignments. After the implementation of a missing data filter, we retained sequences from 986 nuclear loci and 177 plastid regions. Phylogenomic analyses were conducted using both concatenated and summary-coalescence methods. The resulting phylogenies were highly resolved and revealed three distinct evolutionary lineages consisting of the African species traditionally referred to as Carduus and Cirsium. Consequently, we propose the three new genera Afrocarduus, Afrocirsium and Nuriaea; the latter did notably not belong to the Carduus-Cirsium group. We detected some incongruences between the phylogenies based on concatenation vs. coalescence and on nuclear vs. plastid datasets, likely attributable to incomplete lineage sorting and/or hybridization