Actividad proapoptótica de la estaurosporina en cultivos axénicos de Trypanosoma evansi

Trypanosoma evansi is a blood protozoan parasite of the genus Trypanosoma which is responsible for surra (Trypanosomosis) in domestic and wild animals. This study addressed apoptotic-like features in Trypanosoma evansi in vitro. The mechanism of parasite death was investigated using staurosporine as an inducing agent. We evaluated its effects through several cytoplasmic features of apoptosis, including cell shrinkage, phosphatidylserine exposure, maintenance of plasma membrane integrity, and mitochondrial trans-membrane potential. For access to these features we have used the flow cytometry and fluorescence microscopy with cultures in the stationary phase and adjusted to a density of 10(6) cells/mL. The apoptotic effect of staurosporine in T. evansi was evaluated at 20 nM final concentration. There was an increase of phosphatidylserine exposure, whereas mitochondrial potential was decreased. Moreover, no evidence of cell permeability increasing with staurosporine was observed in this study, suggesting the absence of a necrotic process. Additional studies are needed to elucidate the possible pathways associated with this form of cell death in this hemoparasite.Trypanosoma evansi es un hemoparásito, el cual es el agente causal de la surra (tripanosomiasis) en mamíferos, perteneciente al orden Kinetoplastidae. Este estudio se oriento a caracterizar la muerte celular similar a apoptosis en cultivos in vitro de Trypanosoma evansi a través del uso del inductor esturosporina. Este efecto se evaluó a través de diversos aspectos fenotípicos de la apoptosis: el encogimiento celular, la exposición de fosfatidilserina, el mantenimiento de la integridad de la membrana plasmática y el potencial de membrana mitocondrial. Para evaluar estas características se utilizaron técnicas de citometría de flujo y microscopía de fluorescencia con cultivos en fase estacionaria ajustados a una densidad de 10(6) células/mL. El efecto apoptótico de la estaurosporina en Trypanosoma evansi fue evaluado a una concentración de 20 nM. Se evidenció un aumento de la exposición a fosfatidilserina, mientras que el potencial mitocondrial disminuyó. Por otra parte, no hay evidencias de aumento de la permeabilidad celular con estaurosporina, sugiriendo la ausencia de un proceso necrótico. Estudios adicionales son necesarios para dilucidar las posibles vías asociadas con esta forma de muerte celular en este hemoparásito

Monolithically Integrable Si-Compatible Light Sources

On the road to integrated optical circuits, the light emitting device is considered the bottleneck preventing us from arriving to the fully monolithic photonic system. While the development of silicon photonics keeps building momentum, the indirect bandgap nature of silicon represents a major problem for obtaining an integrated light source. Novel nanostructured materials based on silicon, such as silicon-rich oxide (SRO) containing silicon nanoparticles, present intense luminescence due to quantum phenomena. Using this material, electroluminescent devices have already been fabricated and even integrated in monolithic photonic circuits by fully complementary metal oxide semiconductor (CMOS) compatible techniques, opening the door to seamless electronic and photonic integration. The present work discusses some of the strategies used to improve the performance of SRO-based electroluminescent devices fully compatible with CMOS technology. Results from the characterization of devices obtained using different approaches are presented and compared

Differential cytokine profiling in Chagasic patients according to their arrhythmogenic-status

[Background] Changas disease is caused by the protozoan Trypanosoma cruzi and is characterized by heart failure and sudden death. Identifying which factors are involved in evolution and treatment response is actually challenging. Thus, the aim of this work was to determine the Th1/Th17 (IL-6, IL-2, TNF, IL-17 and IFN-γ) and Th2 (IL-4 and IL-10) serum profile in Venezuelan Chagasic patients stratified according amiodarone treatment, hypertension and arrhythmias.[Methods] Sera from 38 chagasic patients were analyzed to determine the level of cytokines by Multiplexed Bead-Based Immunoassays. ANOVA test was applied to determine differences for each group. Additionally, a Linear Discriminant Analysis (LDA) was applied to observe the accuracy of different cytokines to discriminate between the groups.[Results] The levels of several cytokines were significantly higher in the high-risk of sudden death and untreated group. LDA showed that IL-2, IFN-γ and IL-10 were the best cytokines for discriminating between high-risk of sudden death and untreated patients versus low-risk of sudden death, treated and control groups.[Conclusions] High IL-2 levels seem to identify patients with high-risk of sudden death and seems adequate as treatment efficacy marker. To our knowledge, this is the first report about the anti-inflammatory role of the amiodarone in Chagas disease, suggesting an inmunomodulatory effect that may be exploited as coadjutant therapy in chronic Chagas disease.This work was supported by MF grant (SN/2013) and NG grant (CEAL-AL/2015-12) from “UAM-Banco Santander” for collaboration with Latin America; by NG grants from “Fondo de Investigaciones Sanitarias/FEDER” (PS09/00538 and PI12/00289), MINECO/FEDER (SAF2015-63868-R) “Universidad Autónoma de Madrid” and “Comunidad de Madrid” (CC08-UAM/SAL-4440/08); by MF grants from “Ministerio de Ciencia e Innovación” (SAF2010-17833 and SAF2013-42850-R), MINECO/FEDER (SAF2016-75998-R), “Red de Investigación de Centros de Enfermedades Tropicales” (RICET RD12/0018/0004; RICET RD16/0027/0006); European Union (HEALTH-FE-2008-22303, ChagasEpiNet, HOMIN - 317057 - FP7-PEOPLE-2012-ITN); AECID (A/025417/09 and A/031735/10), Comunidad de Madrid (S-2010/BMD-2332), Proyecto Excelencia BIOIMID - IIS La Princesa and “Fundación Ramón Areces”; and by HR and AM grants from Instituto Venezolano de Investigaciones Científicas (IVIC-1365).Peer reviewe

Luminescent Devices Based on Silicon-Rich Dielectric Materials

Luminescent silicon‐rich dielectric materials have been under intensive research due to their potential applications in optoelectronic devices. Silicon‐rich nitride (SRN) and silicon‐rich oxide (SRO) films have been mostly studied because of their high luminescence and compatibility with the silicon-based technology. In this chapter, the luminescent characteristics of SRN and SRO films deposited by low‐pressure chemical vapor deposition are reviewed and discussed. SRN and SRO films, which exhibit the strongest photoluminescence (PL), were chosen to analyze their electrical and electroluminescent (EL) properties, including SRN/SRO bilayers. Light emitting capacitors (LECs) were fabricated with the SRN, SRO, and SRN/SRO films as the dielectric layer. SRN‐LECs emit broad EL spectra where the maximum emission peak blueshifts when the polarity is changed. On the other hand, SRO‐LECs with low silicon content (~39 at.%) exhibit a resistive switching (RS) behavior from a high conduction state to a low conduction state, which produce a long spectrum blueshift (~227 nm) between the EL and PL emission. When the silicon content increases, red emission is observed at both EL and PL spectra. The RS behavior is also observed in all SRN/SRO‐LECs enhancing an intense ultraviolet EL. The carrier transport in all LECs is analyzed to understand their EL mechanism

Can the intake of antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes?

Background: Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria parasites (Plasmodium), intracellular haemosporidians (Haemoproteus, Leucocytozoon), unicellular flagellate protozoans (Trypanosoma) and microfilariae in 19 Psittaciformes species from a range of habitats in the Indo-Malayan, Australasian and Neotropical regions. We gathered additional data on hemoparasites in wild Psittaciformes from the literature. We considered factors that may control the presence of hemoparasites in the Psittaciformes, compiling information on diet, habitat, and climate. Furthermore, we investigated the role of diet in providing antiparasitic secondary metabolites that could be used as self-medication to reduce parasite load. Results: We found hemoparasites in only two of 19 species sampled. Among them, all species that consume at least one food item known for its secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, were free from hemoparasites. In contrast, the infected parrots do not consume food items with antimalarial or even general antiparasitic properties. We found that the two infected species in this study consumed omnivorous diets. When we combined our data with data from studies previously investigating blood parasites in wild parrots, the positive relationship between omnivorous diets and hemoparasite infestation was confirmed. Individuals from open habitats were less infected than those from forests. Conclusions: The consumption of food items known for their secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, as well as the higher proportion of infected species among omnivorous parrots, could explain the low prevalence of hemoparasites reported in many vertebrates

La Gestión Estratégica. Aspectos a considerar e integrar creativamente a su ejercicio

El presente articulo aborda aspectos relacionados con la Gestión Estratégica, específicamente con uno de sus pilares fundamentales , la actitud estratégica, la cual incide significativamente en los resultados de toda organización objeto de un proceso de planeación estratégica , independientemente del sector o rama de la economía que se trate. La actitud estratégica es definida conjuntamente con el pensamiento e intención estratégica. Se destacan los elementos característicos de la actitud estratégica, los que constituyen elementos significativos para el accionar de las organizaciones en escenarios tan dinámicos y complejos en el mundo contemporáneo. Se integra al articulo el Comportamiento Organizacional, destacando como el mismo se nutre de toda una serie de ciencias del comportamiento, entre la que se destaca la psicología social, la cual brinda valiosas contribuciones en lo particular lo relacionado con las actitudes, abordando la definición, la estructura del as actitudes entre otros aspectos de interés vinculado a la misma, lo cual propicia un marco teórico referencial para ser considerado objetiva y creativamente al actitud estratégica, estableciendo interrogantes, con el fin de valorar la medida de análisis, reflexión y toma de decisiones de los lideres y equipos directivos sobre la consideración de las contribuciones de la psicología social en el marco de las actitudes y que al ser considerados en lo relacionado con la actitud estratégica propicia una mayor y efectiva materialización de sus rasgos característicos tan importantes para el accionar de las organizaciones empresariales como pilar fundamental que es de la Gestión Estratégica