5,357 research outputs found

    Caracterización de las condiciones clínicas y parámetros ecocardiográficos de la presión pulmonar en caninos con enfermedad valvular degenerativa

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    Pulmonary hypertension (PH) is common in dogs with degenerative valvular disease (DVD) and is caused by an increase in left atrial pressure and pulmonary venous pressure. Cardiac catheterization is considered the gold standard for the diagnosis of PH. Tricuspid regurgitation (TR), measured by Doppler echocardiography, is commonly used in the clinic to determine the pressure gradient (PG) of TR reflecting pulmonary arterial systolic pressure (PAP). For the characterization of the echocardiographic parameters of pulmonary pressure in canines with DVD, 161 echocardiographic cases and the respective clinical histories of the patients admitted to the Veterinary Cardiology Unit of the city of Bogotá in a period of 8 months (November 2016 - June 2017) were evaluated. All patients diagnosed with DVD were grouped within the classification of the American College Veterinary Internal Medicine (ACVIM), and some essential criteria were evaluated to assign patients to the study group. None of the patients had a primary or secondary disease of cardiopulmonary origin, different from the one already mentioned. Echocardiographic parameters associated with the presentation of PH were taken and statistical analyses were carried out to determine the frequency of presentation, relevance and importance of each of these parameters with the development of the disease. In conclusion, the highest percentage of patients diagnosed with PH were classified as B2 within the ACVIM, which suggests that this group of patients has a greater possibility of presenting PH and, therefore, a greater possibility of congestion. No relevant data were found regarding the altitude of the city (>2600 m above the sea level).La hipertensión pulmonar (HP) es común en perros con enfermedad valvular degenerativa (EVD) y es causada por un aumento de la presión auricular izquierda y presión venosa pulmonar. La cateterización cardíaca es considerada el estándar de oro para el diagnóstico de la HP. La regurgitación tricúspidea (RT), medida por ecocardiografía Doppler, es comúnmente usada en la clínica para determinar el gradiente de presión (GP) de RT reflejando la presión arterial pulmonar (PAP) sistólica. Con el objetivo de caracterizar los parámetros ecocardiográficos de presión pulmonar en caninos con EVD, se revisaron 161 estudios ecocardiográficos y las respectivas historias clínicas de los pacientes que ingresaron a la Unidad de Cardiología Veterinaria en la ciudad de Bogotá en un periodo de 8 meses (noviembre de 2016 y junio de 2017). Se incluyeron todos los pacientes con diagnóstico de EVD, se catalogaron dentro de la clasificación del American College Veterinary Internal Medicine (ACVIM), y se evaluaron algunos criterios indispensables para pertenecer al grupo de estudio. Ninguno de los pacientes presentaba enfermedad primaria o secundaria de origen cardiopulmonar, diferente a la ya mencionada. Se tomaron parámetros ecocardiográficos asociados a la presentación de HP y se realizaron análisis estadísticos para determinar la frecuencia de presentación, relevancia e importancia de cada uno de estos parámetros con el desarrollo de la enfermedad. En conclusión, el mayor porcentaje de pacientes diagnosticados con HP se encontraban clasificados como B2 dentro del ACVIM, lo que sugiere que este grupo de pacientes tiene una mayor posibilidad de presentar HP y, por lo tanto, una mayor posibilidad de congestión. No se encontraron datos relevantes con respecto a la altura de la ciudad (>2600 msnm)

    Conformational Isomerization Involving Conserved Proline Residues Modulates Oligomerization of the NS1 Interferon Response Inhibitor from the Syncytial Respiratory Virus

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    Interferon response suppression by the respiratory syncytial virus relies on two unique nonstructural proteins, NS1 and NS2, that interact with cellular partners through high-order complexes. We hypothesized that two conserved proline residues, P81 and P67, participate in the conformational change leading to oligomerization. We found that the molecular dynamics of NS1 show a highly mobile C-terminal helix, which becomes rigid upon in silico replacement of P81. A soluble oligomerization pathway into regular spherical structures at low ionic strengths competes with an aggregation pathway at high ionic strengths with an increase in temperature. P81A requires higher temperatures to oligomerize and has a small positive effect on aggregation, while P67A is largely prone to aggregation. Chemical denaturation shows a first transition, involving a high fluorescence and ellipticity change corresponding to both a conformational change and substantial effects on the environment of its single tryptophan, that is strongly destabilized by P67A but stabilized by P81A. The subsequent global cooperative unfolding corresponding to the main β-sheet core is not affected by the proline mutations. Thus, a clear link exists between the effect of P81 and P67 on the stability of the first transition and oligomerization/aggregation. Interestingly, both P67 and P81 are located far away in space and sequence from the C-terminal helix, indicating a marked global structural dynamics. This provides a mechanism for modulating the oligomerization of NS1 by unfolding of a weak helix that exposes hydrophobic surfaces, linked to the participation of NS1 in multiprotein complexes.Fil: Conci, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Álvarez Paggi, Damián Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: de Oliveira, Guilherme A. P.. Universidade Federal do Rio de Janeiro; BrasilFil: Pagani, Talita Duarte. Universidade Federal do Rio de Janeiro; BrasilFil: Esperante, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Borkosky, Silvina Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Aran, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Alonso, Leonardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Mohana Borges, Ronaldo. Universidade Federal do Rio de Janeiro; BrasilFil: de Prat Gay, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin

    The Role of Oxidative Stress and Lipid Peroxidation in Ventricular Remodeling Induced by Tobacco Smoke Exposure after Myocardial Infarction

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    OBJECTIVE: To evaluate the roles of oxidative stress and lipid peroxidation in the ventricular remodeling that is induced by tobacco smoke exposure after myocardial infarction.METHODS: After induced myocardial infarction, rats were allocated into two groups: C (control, n=25) and ETS (exposed to tobacco smoke, n=24). After 6 months, survivors were submitted to echocardiogram and biochemical analyses.RESULTS: Rats in the ETS group showed higher diastolic (C = 1.52 +/- 0.4 mm(2), ETS = 1.95 +/- 0.4 mm(2); p=0.032) and systolic (C = 1.03 +/- 0.3, ETS = 1.36 +/- 0.4 mm(2)/g; p=0.049) ventricular areas, adjusted for body weight. The fractional area change was smaller in the ETS group (C = 30.3 +/- 10.1 %, ETS = 19.2 +/- 11.1 %; p=0.024) and E/A ratios were higher in ETS animals (C = 2.3 +/- 2.2, ETS = 5.1 +/- 2.5; p=0.037). ETS was also associated with a higher water percentage in the lung (C = 4.8 (4.3-4.8), ETS = 5.5 (5.3-5.6); p=0.013) as well as higher cardiac levels of reduced glutathione (C = 20.7 +/- 7.6 nmol/mg of protein, ETS = 40.7 +/- 12.7 nmol/mg of protein; p=0.037) and oxidized glutathione (C = 0.3 +/- 0.1 nmol/g of protein, ETS = 0.9 +/- 0.3 nmol/g of protein; p=0.008). No differences were observed in lipid hydroperoxide levels (C = 0.4 +/- 0.2 nmol/mg of tissue, ETS = 0.1 +/- 0.1 nmol/mg of tissue; p=0.08).CONCLUSION: In animals exposed to tobacco smoke, oxidative stress is associated with the intensification of ventricular re-remodeling after myocardial infarction

    Simulation of macauba palm cultivation: an energy-balance and greenhouse gas emissions analysis

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    The expansion of the production and use of bioenergy is one of the most efficient mechanisms to reduce greenhouse gas (GHG) emissions. Nevertheless, the environmental impact of the production processes for many raw materials remains unexplored. Several studies have pointed to macauba palm as a promising species for biofuel production in the tropics, but investigations on the environmental benefits of its cultivation have not been reported so far. In this work, an analysis of macauba production system in terms of GHG emissions and CO2 uptake has been conducted for a productive cycle. The energy conversion efficiency per unit area of land has been put in relationship with crop productivity and related to the dilution effect of production inputs. Simulation results estimate GHG emissions of 180 Mg CO2eq·ha-1 and a CO2 fixation ranging from 796 to 1137 Mg CO2eq·ha-1. The net energy balance would reach 512.3 GJ·ha-1 and energy efficiency would be 24.2 GJ·GJ-1. These results suggest that macauba would outperform traditional energy crops such as sugarcane, oil palm, sunflower, corn or jatropha in terms of efficiency. The domestication and exploitation in extensive farming of this species as an agroforestry crop, although still at an early stage, has a bright future

    Coordination of power reactive management considering variations in wind speed from wind farms and power transmission limits

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    Proceedings of: XLI Ibero-Latin-American Congress on Computational Methods in Engineering, ABMEC. Foz do Iguaçu/PR, Brazil, November 16-19, 2020This paper presents a methodology that allows performing the optimized and coordinated management of reactive power injection in power systems with wind farms and other sources of reactive injection, such as capacitor banks or static voltage compensators, minimizing the losses in the transmission power system. The variation in wind speed is characterized by the Weibull distribution. The values of this distribution are used as input data for the optimal power flow model whose output provides a sample of values for defining the confidence intervals of the injected reactive power, as well as the voltage values in each bus of the electrical system. The proposed methodology was tested using a real 140 buses system to determine the dispatch of reactive sources available in the power system. The results found by the proposal can help to make a better management of the available reactive sources in the real-time operation

    The movement ecology of seagrasses

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    A movement ecology framework is applied to enhance our understanding of the causes, mechanisms and consequences of movement in seagrasses: marine, clonal, flowering plants. Four life-history stages of seagrasses can move: pollen, sexual propagules, vegetative fragments and the spread of individuals through clonal growth. Movement occurs on the water surface, in the water column, on or in the sediment, via animal vectors and through spreading clones. A capacity for long-distance dispersal and demographic connectivity over multiple timeframes is the novel feature of the movement ecology of seagrasses with significant evolutionary and ecological consequences. The space–time movement footprint of different life-history stages varies. For example, the distance moved by reproductive propagules and vegetative expansion via clonal growth is similar, but the timescales range exponentially, from hours to months or centuries to millennia, respectively. Consequently, environmental factors and key traits that interact to influence movement also operate on vastly different spatial and temporal scales. Six key future research areas have been identified

    Alveolar socket healing in 5-lipoxygenase knockout aged female mice treated or not with high dose of zoledronic acid

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    This study investigated the role 5-lypoxigenase (5-LO) on alveolar socket healing in aged female mice treated with zoledronic acid (ZL). Forty 129/Sv female mice (64-68 weeks old), 20 wild type (WT) and 20 5-LO knockout (5LOKO) were equally distributed according to ZL treatment: WT Control, WT ZL, 5LOKO Control, and 5LOKO ZL. ZL groups were treated with an intraperitoneal injection of 250 µg/Kg of ZL, while controls were treated with saline. Treatments were administered once a week, starting four weeks before surgery for tooth extraction and until 7 and 21 days post-surgery. Mice were euthanized for a comprehensive microscopic analysis (microCT, histomorphometry and immunohistochemistry). WT ZL mice presented intense inflammatory infiltrate (7 days), delayed bone formation (21 days), reduced collagenous matrix quality, and a deficiency in Runx-2 + , TRAP + , and macrophages as compared to controls. 5LOKO ZL animals presented decreased number of Runx-2 + cells in comparison to 5LOKO Control at 7 days, but no major changes in bone healing as compared to WT or 5LOKO mice at 21 days. The knockout of 5LO favored intramembranous bone healing in aged female mice, with a direct impact on inflammatory response and bone metabolism on the development of ONJ-like lesions
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