567 research outputs found

    Consensos, guías y protocolos

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    Uno de los campos más importantes dentro de la evaluación en medicina, es la síntesis de conocimientos, basada en estrategias preventivas, diagnósticas y terapéuticas. Dentro de la síntesis de conocimientos a las cuales recurre la evaluación médica, figuran las conferencias de consenso. Las conferencias de consenso permiten establecer el estado de los conocimientos en un momento dado (estado del arte), así como poder definir una posición cuando se trata de una conducta discutible, ya sea preventiva, diagnóstica e incluso terapéutica

    Stem cells labeled with superparamagnetic iron oxide nanoparticles in a preclinical model of cerebral ischemia: a systematic review with meta-analysis

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    Introduction: Although there is an increase in clinical trials assessing the efficacy of cell therapy in structural and functional regeneration after stroke, there are not enough data in the literature describing the best cell type to be used, the best route, and also the best nanoparticle to analyze these stem cells in vivo. This review analyzed published data on superparamagnetic iron oxide nanoparticle (SPION)-labeled stem cells used for ischemic stroke therapy.Method: We performed a systematic review and meta-analysis of data from experiments testing the efficacy of cellular treatment with SPION versus no treatment to improve behavioral or modified neural scale outcomes in animal models of stroke by the Cochrane Collaboration and indexed in EMBASE, PubMed, and Web of Science since 2000. To test the impact of study quality and design characteristics, we used random-effects meta-regression. in addition, trim and fill were used to assess publication bias.Results: the search retrieved 258 articles. After application of the inclusion criteria, 24 reports published between January 2000 and October 2014 were selected. These 24 articles were analyzed for nanoparticle characteristics, stem cell types, and efficacy in animal models.Conclusion: This study highlights the therapeutic role of stem cells in stroke and emphasizes nanotechnology as an important tool for monitoring stem cell migration to the affected neurological locus.Instituto Israelita de Ensino e Pesquisa Albert EinsteinCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPEGHosp Israelita Albert Einstein, BR-05651901 São Paulo, BrazilUniversidade Federal de São Paulo, BR-04021001 São Paulo, SP, BrazilSanta Casa Misericordia São Paulo, BR-01221020 São Paulo, SP, BrazilUniv São Paulo, Inst Matemat & Estat, BR-05508090 São Paulo, SP, BrazilUniv São Paulo, LIM44, BR-05403000 São Paulo, SP, BrazilUniversidade Federal de São Paulo, BR-04021001 São Paulo, SP, BrazilWeb of Scienc

    A comparison and methodological proposal for hybrid approaches to quantify environmental impacts: A case study for renewable energies

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    The transition towards a more sustainable and decarbonised energy system is mandatory for achieving global climate objectives, and counting on proper tools to evaluate sustainability is essential. Among sustainability assessment methodologies, hybrid approaches integrating Input-Output analysis (IOA) and Life Cycle Assessment (LCA) are often proposed to overcome limitations and take advantage of strengths of both methodologies. In this paper we propose a new hybrid tiered approach, named Identification and Subtraction Method (ISM). Through a case study of Concentrated Solar Power (CSP) technology, we test the proposed method assessing seven environmental indicators and compare the results obtained by different methodological approaches: Environmental Extended Multiregional Input-Output (EMRIO), LCA and two hybrid approaches. Results showed that, in general, LCA and EMRIO provide the lowest and uppest impact values, respectively. The ISM method expands the LCA boundaries by including indirect impacts, avoiding double-counting and retaining the technological detail and representativeness of the LCA. The main advantage is the ability to establish with high accuracy the impact coming from the LCA system boundaries. Furthermore, ISM is easy to undertake for LCA practitioners, is a low time-consuming hybrid approach once the LCA and EMRIO models are run, and it does not require the alteration of the IO matrix as other hybrid methods. However, the need to perform the EMRIO and LCA analysis could imply high detailed data needs. An additional limitation of the model is that it is not be able to include partial contributions from EMRIO sectors. The highest differences between results obtained by the different methods are found in the assessment of local impacts and the resources depletion, while the methods tend to agree more on global and regional impacts quantification. However, there are limitations to the implementation of the impact characterization methods that should be borne in mind when comparing the results of the different methods

    Hybrid Approaches to Quantify the Environmental Impacts of Renewable Energy Technologies: A Comparison and Methodological Proposal

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    The transition towards a more sustainable and decarbonised energy system is mandatory for achieving global climate objectives, and renewable energies are essential to this purpose. There are different methodologies to assess the sustainability, each with its strengths and limitations. Thus, hybrid approaches integrating Input-Output analysis and Life Cycle Assessment (LCA) are often proposed to overcome limitations and take advantage of strengths of renewable technologies. Through a case study of Concentrated Solar Power (CSP) technology, a potentially significant technology in the European context, this study provides an environmental assessment of seven environmental indicators by applying and comparing methodological approaches: Environmental Extended Multiregional Input-Output (EMRIO), Life Cycle Assessment and two hybrid approaches used in literature. Among those, we propose a new hybrid tieredapproach, named Identification and Subtraction Method (ISM), that expands the boundaries of the LCA method, identifying in MRIO results the impacts from sectors not included in the LCA. The results indicated that the LCA and EMRIO approaches provide impact values in the lower and upper ranges, respectively, although there are some exceptions. The proposed ISM method achieves to expand the LCA boundaries by including indirect impacts, avoiding any double-counting and retaining the technological detail and representativeness of the process-based LCA.The highest differences between methods are found in the assessment of local impacts and the depletion of the resources for either fuels or minerals and metals, while the methods tend to agree more on the quantification of global and regional impacts. However, there are limitations to the implementation of the impact characterization methods and the quantification of the potential impacts that should be borne in mind when comparing the results of the different methods

    DISTRIBUCION Y ABUNDANCIA DE ESPECIES DE PLANTAS EN EL GRADIENTE HÍDRICO DE LA ZONA PALUSTRE DEL HUMEDAL “LAGUNA LOS MILAGROS”

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    El estudio se realizó en la zona palustre del humedal “Laguna Los Milagros”, Leoncio Prado, Huánuco -Perú; con la finalidad de determinar la distribución y abundancia de especies de plantas en relación algradiente hídrico en la estación lluviosa y en la estación seca. El área mínima de muestreo fue de 8 m2 y seutilizó el método sistemático para la ubicación de las unidades muestrales y la línea de Canfield a lo largo delgradiente hídrico. Los datos de cobertura, profundidad del agua y la humedad del suelo fueron evaluadosmediante el análisis de regresión y el análisis clúster (UPGMA).La distribución, composición y abundancia de especies de plantas varían en relación al gradiente hídrico. Lastendencias en la abundancia y las asociaciones de las especies a lo largo de este gradiente a distintas escalasespaciales muestran diferencias significativas, por lo que se presentan tres tipos de asociaciones de especies ypor lo tanto, tres tipos de hábitats. Aciotis polystachya, Andropogon bicornis, Canavalia eurycarpa,Lycopodium cernum, Pseudelephantopus spicatus y Cissus sp se distribuyen en hábitats no inundados;Cabomba furcata, Eleocharis elegans, Hymenachne amplexicaulis, Scoparia dulcis, Isachne polygonoides,Xyris laxifolia, Tonina fluviatilis, Scleria microcarpa y Ludwigia affinis se distribuyen en hábitats inundadosy; Aeschynomene sensitiva, Calopogonium mucunoides, Cyperus difformis, Desmoscelis villosa, Homolepisaturensis, Sauvagesia erecta, Chloris radiata, Psidium acutangulum y Selaginella mertensi en hábitatstransicionales.Palabras claves: Distribución, gradiente hídrico, zona palustre, humedal

    Synthesis, physicochemical characterization and biological activity of anandamide/ε-polycaprolactone nanoparticles obtained by electrospraying

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    Drug encapsulation in nanocarriers such as polymeric nanoparticles (Nps) may help to overcome the limitations associated with cannabinoids. In this sense, our work aimed to highlight the use of electrospraying technique for the development of carrier Nps of anandamide (AEA), an endocannabinoid with attractive pharmacological effects but underestimated due to its unfavorable physicochemical and pharmacokinetic properties added to its undesirable effects at the level of the central nervous system. We characterized physicochemically and evaluated in vitro biological activity of anandamide/ε-polycaprolactone nanoparticles (Nps-AEA/PCL) obtained by electrospraying in epithelial cells of human proximal tubule (HK2), to prove the utility of this method and to validate the biological effect of Nps-AEA/PCL. We obtained particles from 100 to 900 nm of diameter with a predominance of 200 a 400 nm. Their zeta potential was -20±1.86 mV. We demonstrated the stable encapsulation of AEA in Nps-AEA/PCL, as well as its dose-dependent capacity to induce the expression of iNOS and NO levels and to decrease the Na+/K+ ATPase activity in HK2 cells. Obtaining Nps-AEA/PCL by electrospraying would represent a promising methodology for a novel AEA pharmaceutical formulation development with optimal physicochemical properties, physical stability and biological activity on HK2 cells.Fil: Martín Giménez, Virna Margarita. Universidad Católica de Cuyo - Sede San Juan; ArgentinaFil: Russo, Marcos Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Narda, Griselda Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Fuentes, Lucía B.. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: Mazzei, Luciana Jorgelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; ArgentinaFil: Gamarra Luques, Carlos Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Kassuha, Diego Enrique. Universidad Católica de Cuyo - Sede San Juan; ArgentinaFil: Manucha, Walter Ariel Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; Argentin

    Ferromagnetic resonance for the quantification of superparamagnetic iron oxide nanoparticles in biological materials

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    The aim of the present work is the presentation of a quantification methodology for the control of the amount of superparamagnetic iron oxide nanoparticles (SPIONs) administered in biological materials by means of the ferromagnetic resonance technique (FMR) applied to studies both in vivo and in vitro. The in vivo study consisted in the analysis of the elimination and biodistribution kinetics of SPIONs after intravenous administration in Wistar rats. The results were corroborated by X-ray fluorescence. For the in vitro study, a quantitative analysis of the concentration of SPIONs bound to the specific AC133 monoclonal antibodies was carried out in order to detect the expression of the antigenic epitopes (CD133) in stem cells from human umbilical cord blood. In both studies FMR has proven to be an efficient technique for the SPIONs quantification per volume unit (in vivo) or per labeled cell (in vitro)

    Evaluación del efecto antiulceroso del extracto acuoso y metanólico de las semillas de lupinus mutabilis sweet (tarwo, chocho) en ratas

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    In the present research, we have evaluated the effect of Lupinus mutabilis Sweet's seed, as watery and methanolic extracts on the gastric mucous of rats, following the Lee's method. Indometacin in doses higher than 50 mg per kg of weight causes lineal lesions, enlarging and dilatation of small intestine; partial obstruction, acute and chronic transmural granulomatous inflamation; abscess in the intestine's crypts and fibrosis. 2000 mg/kg of weight of the watery extract of the Lupinus was administered by mouth and 400 mk/kg of the methanolic extract by the same way.We use four groups of ten male rats each one with 250 g of weight approximately that were previously conditionated in our laboratory supplying food and water ad libitum. The animals were distributed in four groups in aleatory way and they received saline solution, ranitidine, watery extract of Lupinus and methanolic extract of Lupinus respectively. All substances were administered by oral route 30 minutes before to administer Indometacina to the animals that were in fast for 48 hours. Five hours later the animals were sacrificed and submitted to laparotomy in order to observe the macroscopically anti ulcerogenic effect that was evident and statistically significant with a value of p= 0,0013; microscopically was p= 0,0053.The anti ulcerogenic effect was: 57 % for Ranitidine, 60 % for watery extract of Lupinus and 40 % for methanolic extract of Lupinus; besides we could observe normalization of gastric mucous architecture and lowing of granulocites inftltration.We found that both extracts of Lupinus protected the gastric mucous from the lesions caused by Indometacina and could be an alternative for the treatment of gastroduodenal ulcer.En la presente investigación realizada con semilla de lupjnus mutabilis sweet se ha podido evaluar el efecto del extracto acuoso y del extracto metanólico sobre las lesiones producidas en la mucosa gástrica de ratas de acuerdo a la técnica de Lee. La indometacina en dosis superiores a 50 mg/Kg de peso produce lesiones lineales, engrosamiento y dilatación del intestino delgado, adhesiones, obstrucción parcial, inflamación granulomatosa transmural aguda y crónica, absceso en las criptas y fibrosis. El extracto acuoso en cocimiento, de Lupinus mutabilis Sweet fue administrado a la dosis de 2000mg/Kg de peso y el extracto metanólico a una dosis de 400mg/Kg.Se utilizaron cuatro grupos de ratas machos de aproximadamente 250g de peso a las que se les acondicionó en el Bioterio de la Facultad y se les suministró alimento y agua ad libitum. Los animales fueron distribuidos en G1: Control, G2: Ranitidina, G3: Extracto acuoso en conocimiento del Lupinus mutabilis Sweet y G4: Extracto metanólico de Lupinus mutabilis Sweet. Las sustancias fueron administradas por vía oral, previo ayuno de 48 horas, media hora antes de la Indometacina. A las cinco horas, los animales fueron sacrificados; realizándose la laparotomía para extraer el estómago y observar las lesiones producidas. Macroscópicamente apreciamos un efecto antiulceroso estadísticamente significativo según la prueba del chi cuadrado, con una probabilidad de p=0.0013 Y microscópicamente una probabilidad de p=0.0053. Para el extracto acuoso en cocimiento se obtuvo un efecto antiulceroso igual al 60%; para la Ranitidina 57% y en menor proporción para el extracto metanólico (40%), pudiendo observarse la normalización de la arquitectura de la mucosa y la atenuación de la infiltración de granulocitos. La observación fue realizada por inspección macroscópica directa y microscópica confirmándose estadísticamente la existencia de propiedades antiulcerosas para el extracto acuoso al 10% en cocimiento por 10 minutos; lo cual podría constituir una alternativa terapéutica en el tratamiento de la úlcera gastroduodenal y además la acción protectora parece ser independiente de la secreción de ácido
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