Producción de Investigación

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    Improved Immuno-Detection of a Low-Abundance Cyclophilin Allows the Confirmation of its Expression in a Protozoan Parasite
    (Immunochemistry & Inmunopathology, 2015) Bustos, Patricia Laura ; Perrone, Alina E ; Milduberger, Natalia A. ; Bua, Jaqueline
    Protein samples can be challenging to analyze due to the presence of high-abundance proteins masking low-abundance proteins of interest, such as biomarkers and novel physiological mediators. Cyclophilins are chaperones involved in the cis/trans isomerization of peptidyl-prolyl bonds in peptides or proteins and have been found in every organism sequenced to date. Although considerable progress has been made in the characterization of some cyclophilins expressed in diverse parasites invading humans, the main aspects of low-abundance members of this family remain unknown. In the present work, we present that the combined strategy of using more specific antibodies and increasing the presence of subcellular proteins in the sample, allowed us to confirm the expression of a 21.1 kDa cyclophilin for the first time in Trypanosoma cruzi.
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    Improved immuno-detection of a low-abundance cyclophilin allows the confirmation of its expression in a protozoan parasite
    (Hilaris, 2015-10-6) Bustos, Patricia L. ; Perrone, Alina E ; Milduberger, Natalia A. ; Bua, Jaqueline
    Protein samples can be challenging to analyze due to the presence of high-abundance proteins masking low abundance proteins of interest, such as biomarkers and novel physiological mediators. Cyclophilins are chaperones involved in the cis/trans isomerization of peptidyl-prolyl bonds in peptides or proteins and have been found in every organism sequenced to date. Although considerable progress has been made in the characterization of some cyclophilins expressed in diverse parasites invading humans, the main aspects of low-abundance members of this family remain unknown. In the present work, we present that the combined strategy of using more specific antibodies and increasing the presence of subcellular proteins in the sample, allowed us to confirm the expression of a 21.1 kDa cyclophilin for the first time in Trypanosoma cruzi.
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    Oxidative stress damage in the protozoan parasite Trypanosoma cruzi is inhibited by cyclosporin A
    (Parasitology, Cambridge University Press, 2015-2-6) Bustos, Patricia L. ; Perrone, Alina E ; Milduberger, Natalia A. ; Postan, Miriam ; Bua, Jaqueline
    Cyclosporin A (CsA) specifically inhibits the mitochondrial permeability transition pore (mPTP). Opening of the mPTP, which is triggered by high levels of matrix [Ca2+] and/or oxidative stress, leads to mitochondrial dysfunction and thus to cell death by either apoptosis or necrosis. In the present study, we analysed the response of Trypanosoma cruzi epimastigote parasites to oxidative stress with 5 mM H2O2, by studying several features related to programmed cell death and the effects of pre-incubation with 1 µM of CsA. We evaluated TcPARP cleavage, DNA integrity, cytochrome c translocation, Annexin V/propidium iodide staining, reactive oxygen species production. CsA prevented parasite oxidative stress damage as it significantly inhibited DNA degradation, cytochrome c translocation to cytosol and TcPARP cleavage. The calcein-AM/CoCl2 assay, used as a selective indicator of mPTP opening in mammals, was also performed in T. cruzi parasites. H2O2 treatment decreased calcein fluorescence, but this decline was partially inhibited by pre-incubation with CsA. Our results encourage further studies to investigate if there is a mPTP-like pore and a mitochondrial cyclophilin involved in this protozoan parasite.
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    Ketamine effect on intracellular and mitochondrial calcium mobilization
    (Biocell, 2016) Bustamante, Juanita ; Czerniczyniec, Analía G. ; Lores-Arnaiz, Silvia
    The suppressive effects of ketamine on intracellular calcium has been reported in a variety of cells although the mechanisms involved are not well understood. The aim of this work was to evaluate the ketamine effect on the mitochondrial Ca2+ accumulation and the cellular Ca2+ mobilization using FLUO4-AM and flow cytometry. The results showed that mitochondria from ketamine injected animals presented a lower ability to retain calcium at concentrations higher than 20 µM, as compared with controls (saline injected animals). In addition, ketamine showed a significant decreased KCl-induced intracellular calcium concentration. KCl increased calcium influx through cellular depolarization. According to the data presented herein, ketamine presents a clear inhibitory effect on cytosolic Ca2+ transport mechanisms, independently from their action on the calcium channel associated NMDA receptor.
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    Student Research Work and Modeled Situations in Order to Bridge the Gap between Basic Science Concepts and Those from Preventive and Clinical Practice. Meaningful Learning and Informed beneficience
    (Scientific Research an Academic Publisher, 2016) Prieto González, Elio A.
    Meaningful learning of basic science concepts is a difficult goal to reach among students from different health related university careers. We present an integrative approach based on different educational strategies like problem based and situated learning as well as the use of models and organizers. Three cases from Medicine, Nursing and Nutrition show the difficulties in the comprehension and integration of basic and applied knowledge as well as the educational approaches adopted and the evolution of students. There is a discussion on the ethical relevance of deep basic and applied knowledge in the right solution of problems posed in class that attempt to model real life scenarios. There is a term introduced in this paper: informed beneficence. This concept expresses the assumption that the professional fulfillment of the ethical principle of beneficence is linked to knowledge and skills to propose appropriate solutions to individual or collective health problems.
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    Brain cortex mitochondrial bioenergetics in synaptosomes and non-synaptic mitochondria during aging
    (Neurochemical research, 2016-1-28) Lores-Arnaiz, Silvia ; Lombardi, Paulina ; Karadayian, Analía G. ; Orgambide, Federico ; Cicerchia, Daniela ; Bustamante, Juanita
    Alterations in mitochondrial bioenergetics have been associated with brain aging. In order to evaluate the susceptibility of brain cortex synaptosomes and non-synaptic mitochondria to aging-dependent dysfunction, male Swiss mice of 3 or 17 months old were used. Mitochondrial function was evaluated by oxygen consumption, mitochondrial membrane potential and respiratory complexes activity, together with UCP-2 protein expression. Basal respiration and respiration driving proton leak were decresed by 26 and 33% in sunaptosomes from 17-months old mice, but spare respiratory rate was decreased by 45% in brain cortex non-synaptic mitochondria from 17-month-old mice, as compared with young animales, but respiratory control was not affected. Synaptosomal mitochondria would be susceptible to undergo calcium-induced depolarization in 17 months-old mice, while non synaptic mitochondrian would not be affectred by calcium overload. UCP2 was significantly up-regulated in both synaptosomal and submitochondrial membranes from 17-months old mice, compared to young animals. UCP-2 upregulation seems to be a possible mechanism by which mitochondria would be resistant to suffer oxidative damage during aging.
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    Phospholipid changes in Rhinella arenarum embryos under different acclimation conditions to copper
    (Elsevier, 2016-10) Herkovits, Jorge ; Fridman, Osvaldo ; Fonovich, Teresa M. ; Pérez-Coll, Cristina S. ; José L., D'eramo
    We report phospholipid changes in Rhinella arenarum embryos after applying three acclimation protocols to copper between 40 and 420 ng L- 1. The lower and higher acclimation treatments resulted in embryos' enhanced resistance to this metal. Phospholipid remodeling activity, evident through arachidonic acid radioactivity incorporation increase in phosphatidylcholine (PC) and sphingomyelin (SPH) fractions, was registered in embryos acclimated to the intermediate exposure condition. Concomitantly, a decrease in phosphatidic acid fraction (PA) was registered in the higher acclimation condition. PC/PE radioactivity ratio increased both for medium and high acclimation conditions from 0.493 in control embryos to 1.378 and 1.032 respectively. Phospholipid changes could be relevant for changes in membrane features associated with low level exposures to copper, preparing the embryo for a higher resistance to this metal. The increased resistance to copper could also be associated with both an increase in metallothioneins concentration, as registered with HPLC in all the acclimation conditions, and an increase in the copper bound to the third fraction of metallothioneins separated by this method. Our results point out that even very low level exposure to copper results in phospholipid metabolism changes that could be relevant for the acclimation phenomena.
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    Alcohol hangover: impairments in behavior and bioenergetics in central nervous system
    (Biocell, 2016-4-16) Karadayian, Analía G. ; Bustamante, Juanita ; Lores-Arnaiz, Silvia
    Alcohol hangover (AH) is defined as the temporary state after alcohol binge-like drinking, starting when EtOH is absent in plasma. Results from our laboratory have shown behavioral impairments and mitochondrial dysfunction in an experimental model of AH in mice. Our model consisted in a single i.p. injection of EtOH (3.8 g/kg BW) or saline solution in male and female mice, sacrificing the animals 6 hours after injection. Motor and affective behavior together with mitochondrial function and free radical production were evaluated in brain cortex and cerebellum during AH. Results showed that hangover animals exhibited a significant reduction in neuromuscular coordination, motor strength and locomotion together with a loss of gait stability and walking deficiencies. Moreover, an increment in anxiety-like behavior together with fear-related phenotype and depression signs were observed. In relation to bioenergetics metabolism, AH induced a reduction in oxygen uptake, inhibition of respiratory complexes, changes in mitochondrial membrane permeability, decrease in transmembrane potential, increase in O2•- and H2O2 production and impairment in nitric oxide metabolism. All together our data suggest that the physiopathological state of AH involves behavioral impairments and mitochondrial dysfunction in mouse brain cortex and cerebellum showing the long lasting effects of acute EtOH exposure in CNS.
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    Paraoxonase 1 gene polymorphisms and enzyme activities in coronary artery disease and its relationship to serum lipids and glycemia
    (Elsevier, 2016-8-1) Fridman, Osvaldo ; Riviere, Stephanie ; Fuchs, Alicia Graciela ; Potenzoni, Miguel Ángel ; Porcile, Rafael ; Gariglio, Luis Osvaldo
    Objectives: Oxidative stress and inflammation are important processes in development of atherosclerosis. Paraoxonase 1 (PON1) is a bioscavenger enzyme associated with inflammation and oxidative stress. We evaluate the association of two single nucleotide polymorphisms in PON1 gene, and enzyme activities with lipid profile and glycemia. Methods: This case-control study consisted of 126 patients with coronary artery disease (CAD) and 203 healthy controls. PON Q192R and L55M polymorphisms were detected by real-time PCR. Paraoxonase and arylesterase activities were determined spectrophotometrically. Blood glucose, cholesterol, triglycerides, HDL, and LDL were measured. Results: PON1 QR192 polymorphism had a major effect on paraoxonase but no effect on arylesterase serum activities. Paraoxonase activity was higher in RR genotype and lowest in QQ genotype. Paraoxonase and arylesterase activities were higher in LL and lower in MM genotypes of PON1 LM55 polymorphism. RQ and LM variants showed intermediate activities between respective homozygous. Elevated concentrations of triglycerides in cases correlate with QQ variant or the presence of M allele. Glucose levels were elevated in cases with QQ variant or with the presence of M allele. Cholesterol and LDL did not show variations in control and cases with any variant of both polymorphisms. HDL is lower in cases with respect to controls independently of genotypes. All differences were significant with p < 0.05.
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    Response to the letter to the editor : mitochondria isolated from the striatum of the brain exhibit a higher degree of oxidative phosphorylation coupling, which shows that they are not subject to energetic dysfunction upon acute paraquat administration
    (Springer, 2016-9-29) Czerniczyniec, Analía ; Karadayian, Analía G. ; Bustamante, Juanita ; Lores-Arnaiz, Silvia
    In response to criticisms raised by Professor Rendon regarding our original study “Impairment of striatal mitochondrial function by acute paraquat poisoning” (J Bioenerg Biomembr 47:395–408, 2015), we re-evaluated key methodological aspects and data interpretation. Oxygen consumption rates were measured in the absence and presence of KCN (1.3 mM) and diphenyleneiodonium (DPI, 1 µM) to discriminate KCN-sensitive respiration from paraquat redox cycling. Paraquat inhibited state 4 and state 3 KCN-sensitive respiration by 80% and 62%, respectively, while DPI-sensitive oxygen uptake increased 2.2- to 2.3-fold, confirming both respiratory-chain inhibition and redox-cycling contributions. Respiratory control ratios were deliberately omitted for KCN-sensitive data, as they do not accurately reflect mitochondrial viability under these conditions; instead, direct analysis of metabolic states 4 and 3 revealed clear bioenergetic impairment. Submitochondrial membrane preparations were tested for vesicle formation using FCCP (4 µM); no stimulation of NADH-cytochrome c reductase, succinate-cytochrome c reductase, or cytochrome oxidase activities occurred, and paraquat-induced inhibition (27% in complex I–III and 19% in complex IV) persisted unchanged. Rotenone (3 µM) inhibited NADH-cytochrome c reductase by ~80% in both control and paraquat samples, confirming that measured activity was predominantly rotenone-sensitive complex I–III (32% inhibition by paraquat). These additional controls validate our original methodology and support the conclusion that acute paraquat poisoning impairs striatal mitochondrial bioenergetics through direct respiratory-chain inhibition and increased free-radical production.
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    A homolog of cyclophilin D is expressed in Trypanosoma cruzi and is involved in the oxidative stress–damage response
    (Cell Death Differentiation Association (ADMC), 2017-2-6) Bustos, Patricia L. ; Volta, Viviana J. ; Perrone, Alina E ; Milduberger, Natalia A. ; Bua, Jaqueline
    Mitochondria have an important role in energy production, homeostasis and cell death. The opening of the mitochondrial permeability transition pore (mPTP) is considered one of the key events in apoptosis and necrosis, modulated by cyclophilin D (CyPD), a crucial component of this protein complex. In Trypanosoma cruzi, the protozoan parasite that causes Chagas disease, we have previously described that mitochondrial permeability transition occurs after oxidative stress induction in a cyclosporin A-dependent manner, a well-known cyclophilin inhibitor. In the present work, a mitochondrial parasite cyclophilin, named TcCyP22, which is homolog to the mammalian CyPD was identified. TcCyP22-overexpressing parasites showed an enhanced loss of mitochondrial membrane potential and loss of cell viability when exposed to a hydrogen peroxide stimulus compared with control parasites. Our results describe for the first time in a protozoan parasite that a mitochondrial cyclophilin is a component of the permeability transition pore and is involved in regulated cell death induced by oxidative stress
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    Free radical production and antioxidant status in brain cortex non-synaptic mitochondria and synaptosomes at alcohol hangover onset
    (Elsevier, 2017-7) Karadayian, Analía G. ; Malanga, Gabriela ; Czerniczyniec, Analía G. ; Lombardi, Paulina ; Bustamante, Juanita ; Lores-Arnaiz, Silvia
    Alcohol hangover (AH) is the pathophysiological state after a binge-like drinking. We have previously demonstrated that AH induced bioenergetics impairments in a total fresh mitochondrial fraction in brain cortex and cerebellum. The aim of this work was to determine free radical production and antioxidant systems in non-synaptic mitochondria and synaptosomes in control and hangover animals. Superoxide production was not modified in non-synaptic mitochondria while a 17.5% increase was observed in synaptosomes. A similar response was observed for cardiolipin content as no changes were evidenced in non-synaptic mitochondria while a 55% decrease in cardiolipin content was found in synaptosomes. Hydrogen peroxide production was 3-fold increased in non-synaptic mitochondria and 4-fold increased in synaptosomes. In the presence of deprenyl, synaptosomal H2O2 production was 67% decreased in the AH condition. Hydrogen peroxide generation was not affected by deprenyl addition in non-synaptic mitochondria from AH mice. MAO activity was 57% increased in non-synaptic mitochondria and 3-fold increased in synaptosomes. Catalase activity was 40% and 50% decreased in non-synaptic mitochondria and synaptosomes, respectively. Superoxide dismutase was 60% decreased in non-synaptic mitochondria and 80% increased in synaptosomal fractions. On the other hand, GSH (glutathione) content was 43% and 17% decreased in synaptosomes and cytosol. GSH-related enzymes were mostly affected in synaptosomes fractions by AH condition. Acetylcholinesterase activity in synaptosomes was 11% increased due to AH. The present work reveals that AH provokes an imbalance in the cellular redox homeostasis mainly affecting mitochondria present in synaptic terminals.
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    Mitochondrial permeability transition in protozoan parasites: what we learned from Trypanosoma cruzi
    (Official journal of the Cell Death Differentiation Association, 2017-9-21) Bustos, Patricia Laura ; Perrone, Alina E ; Milduberger, Natalia A. ; Bua, Jaqueline
    Regulated cell death (RCD) involves a genetically encoded molecular machinery, which can be altered by means of pharmacologic and/or genetics interventions targeting the key components of such machinery. A variant of RCD that often manifests with necrotic morphotype critically relies on Cyclophilin D (CyPD), a mitochondrial matrix peptidyl-prolyl isomerase, which is encoded by the Ppif gene. A lot a research has been done in mammals, but still very little is known for protozoan parasites, one of the most ancient phylogenic branches of unicellular eukaryotes. In the present work, we revised the knowledge about mitochondrial permeability transition and regulated cell death in the parasite Trypanosoma cruzi, the causative agent of Chagas disease, that affects 7?8 million people only in South America as well as in other parts of the world through migrations from endemic areas. We also included other protozoan parasites of medical importance to briefly summarize and compare what is known so far about this exciting field of parasitology. We finalized the present article explaining the finding that a homologue of Cyclophilin D, which is the unique genetically confirmed regulator of the mitochondrial permeability transition in mammalian cells, is also expressed in T. cruzi and may be involved in regulated cell death in the parasite. These results were published earlier this year in Cell Death Discovery (Cell Death Discov 3, 16092. 2017 Feb 06). To our knowledge, this is the only Cyclophilin D homologue that has been described in a protozoan parasite. We consider that this parasite mitochondrial cyclophilin could be a valuable drug target for the therapeutic of Chagas disease.
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    Sociedad de la información – Sociedad del conocimiento : la importancia del marco teórico
    (Fundación para el Estudio del Pensamiento Argentino e Iberoamericano (FEPAI), 2018) Regnasco, María Josefina
    La sociedad actual se define a sí misma como la sociedad del conocimiento o sociedad de la información. ¿Qué debe entenderse bajo esta denominación? Debe entenderse que el conocimiento tecno-científico se convierte en el factor principal de la economía y de la mayor productividad. Desde el comienzo del capitalismo, la economía industrial requiere telares, máquinas, motores, sistemas automatizados como la línea de montaje, sistemas de producción de energía, la máquina de vapor, la electricidad, etc. Esta exigencia creciente impulsa el acelerado desarrollo no sólo de técnicas, sino del andamiaje teórico de la ciencia, que desde el siglo XVII revoluciona los conceptos de espacio, de tiempo, de materia, de causalidad, en coherencia con los requerimientos del sistema industrial. A su vez, la transnacionalización de la economía depende de sistemas de comunicación instantáneos. La nueva economía no sería posible, por consiguiente, sin el desarrollo de la informática. Llegamos, así, a la llamada sociedad de la información o sociedad del conocimiento.
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    Hacia la comprensión del lenguaje matemático
    (Edutecne, 2018) Camos, Cristina Mercedes ; Guglielmone, María Lorena
    Esta propuesta pedagógica se deriva del trabajo final, de tipo profesional, de la Maestría en Procesos Educativos mediados por Tecnologías de la Universidad Nacional de Córdoba, Argentina, que estamos llevando a cabo las autoras, en diferentes roles. La Lic. Lorena Guglielmone en su rol de tesista y ejecutora del proyecto, bajo la dirección de la Dra. Cristina Camós. El diseño e implementación de la propuesta tiene como objetivo promover la lectura, la escritura y la comprensión de expresiones simbólicas matemáticas en los alumnos pertenecientes al primer año de las carreras de Contador Público y Licenciatura en Ciencias de la Administración de la Facultad de Ciencias de la Administración de la UNER
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    La gestión de destinos turísticos basado en datos : Big Data y laboratorios de innovación abierta
    (Fondation des Territoires de Demain, 2018) Darín, Susana Beatriz
    Con el surgimiento del BIG DATA el análisis de grandes paquetes de datos derivados de la actividad digital genera nuevas posibilidades para que las empresas del sector turístico puedan mejorar los servicios que ofrecen al mercado, crear nuevos bienes tangibles e intangibles personalizados y hacer más efectiva la gestión de sus negocios tanto interna como externa. La gestión de datos tiene relación con el manejo de los datos, desde su entrada en el ciclo de vida de una investigación, su difusión, archivo y reutilización agregándoles valor. Los datos implican una gestión proactiva desde su creación hasta que se determina que ya no son útiles, garantizando su accesibilidad a largo plazo, su conservación, su autenticidad y su integridad. Es necesario hacerlos visibles, disponibles, seguros, compartibles y útiles. EcoEl presente trabajo tiene por objetivo contribuir y aportar valor a uno de los sectores claves de la economía argentina: el sector turismo. Se toma como punto de partida la importancia de la planificación estratégica del sector utilizando las herramientas tecnológicas informáticas como facilitadoras de la gestión, el “big data” y los laboratorios de innovación abierta, necesarios para la interacción del sector público, sector privado, academia, usuarios y Ong´s del sector.
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    Uzi : máquina virtual sobre plataforma Arduino para robótica educativa. Resultados de la primer etapa
    (Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, 2018) Morán, Jorge Ricardo ; Zabala, Gonzalo Esteban ; Teragni, Matías Iván ; Blanco, Sebastián Gabriel
    El objetivo de este proyecto es el desarrollo de una máquina virtual para Arduino que ejecute un set de instrucciones definido especialmente para facilitar la enseñanza de robótica en las escuelas.
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    UAI Case : enseñanza de ingeniería de software en entornos virtuales colaborativos
    (Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, 2018) De Vincenzi Zemborain, Marcelo Edgardo ; Neil, Carlos Gerardo ; Battaglia, Nicolás ; Martínez, María Roxana
    Hoy en día, existen áreas de conocimiento que requieren de técnicas y herramientas para complementar el proceso de enseñanza y aprendizaje dentro del aula. Es el caso de la Ingeniería de Software (IS), en el que se utilizan tecnologías que ayudan en este proceso, denominadas herramientas CASE (Computer Aided Software Engineering). Además, mediante la inclusión de las TIC en la educación, se generan nuevas oportunidades para el aprendizaje colaborativo, el cual, permite un enfoque basado en la ubicuidad. En este proyecto, se propone la integración de plataformas tecnológicas para el aprendizaje ubicuo colaborativo en cursos relacionados a la IS, en particular, durante el proceso de modelado de software, donde la solución planteada no reemplaza al modelo presencial, sino que brinde un espacio ubicuo de colaboración para el proceso formativo indicado. Esta integración plantea un nuevo enfoque en la metodología de gestión del trabajo en los diversos equipos colaborativos.
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    Interpelaciones entre el Big data y la Teoría de los sistemas sociales : propuestas para un programa de investigación
    (Universidad Maimónides. Editorial Científica y Literaria, 2018) Becerra, Gastón Damián
    En este artículo se presentan tres propuestas de investigación que tienden a vincular el fenómeno tecnológicocultural-social del big data con la teoría de los sistemas sociales de Niklas Luhmann, en un nivel programático. Específicamente, proponemos: (1) explorar la tematización del big data y su relación con la sociedad y la ciencia por parte de distintos sistemas sociales; (2) desarrollar e integrar herramientas y técnicas analíticas de big data en un diseño metodológico empírico coherente con los postulados de la teoría; y (3) llevar adelante un análisis epistemológico de los reclamos cognitivos en la retórica del big data, por la vía de un análisis comparativo con “constructivismo operativo” propuesto por Luhmann como la epistemología de los sistemas sociales.
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    Propuesta de metodología para el proceso de gobierno electrónico utilizando servicios computacionales
    (Universidad Autónoma de Yucatán. Facultad de Matemáticas, 2018) Pons, Claudia Fabiana ; Rodríguez, Rocío Andrea ; Castro, Marcelo
    El objetivo del presente trabajo es presentar una propuesta sobre la metodología para sistematizar y estandarizar los procesos que posibilitan efectivizar Gobierno Electrónico en la gestión pública, a través de servicios computacionales (SCGE). Para lo cual se deberán considerar distintos aspectos tales como software, hardware y comunicaciones, el análisis de estos componentes permitirá generar un modelo integral basado en SCGE. El artículo contiene una breve introducción al concepto de servicios computacionales en el ámbito de gobierno electrónico y una descripción de sus componentes. Posteriormente se presenta un ejemplo sobre un servicio específico y finalmente se describe la metodología método SCGE.