Mendoza, Argentina

National University of Cuyo
Mendoza, Argentina

The National University of Cuyo is the largest center of higher education in the province of Mendoza, Argentina.As of 2005, the university had 12 academic schools in the city of Mendoza and a delegation in the city of San Rafael , in addition to the Balseiro Institute, which is the most developed institute of Physics research in Argentina, located in the city of San Carlos de Bariloche . It includes the University Technological Institute which offers technical education in four other cities in Mendoza province. Moreover, UNCuyo is also devoted to improving education due to having 7 other buildings working as High Schools: C.U.C. Escuela de Comercio Martín Zapata Liceo Agrícola Escuela del Magisterio Colegio de Gral. Alvear. D.A.D Escuela Carmen Vera Arenas Wikipedia.

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Lerena M.C.,National University of Cuyo | Colombo M.I.,National University of Cuyo
Cellular Microbiology | Year: 2011

Autophagy has been implicated as part of the innate immune system against different intracellular microorganisms. Mycobacterium marinum is the causative agent of the fish-tank granuloma and has been widely used as an alternative model to study pathogenic mycobacteria. In this report, we show an active interaction of M. marinum with the autophagic protein LC3, an event that requires pathogen viability and bacterial protein synthesis. Interestingly, M. marinum lacking the region of difference 1 (RD1) is unable to recruit LC3, indicating that a functional ESX-1 secretion system is an absolute requirement for this process. In addition, phagocytosis of the bacteria is also a condition for the LC3 rearrangement induced by M. marinum. We present evidence that this pathogen resides temporarily in a LC3-decorated compartment with late endocytic features but mostly devoid of lysosomal enzymes or degradative properties. In addition our results indicate that autophagy induction by rapamycin treatment leads to maturation of the M. marinum-containing compartment. © 2011 Blackwell Publishing Ltd.

Campoy E.M.,National University of Cuyo | Mansilla M.E.,National University of Cuyo | Colombo M.I.,National University of Cuyo
Cellular Microbiology | Year: 2013

Summary: Coxiella burnetii is a Gram-negative intracellular bacterium. As previously described, both the endocytic and the autophagic pathways contribute to the maturation of Coxiella replicative vacuoles (CRVs). The large CRVs share the properties of both phagolysosomal and autophagolysosomal compartments. Vamp3, Vamp7 and Vamp8 are v-SNAREs involved in the endocytic pathway which participate mainly in the fusion between endosomes and lysosomes. In the present study we observed that Vamp7 interacts with C.burnetii at different infection times (1h-48h p.i.). We have determined that a truncated mutant of Vamp7 (Vamp7 NT) and a siRNA against this SNARE protein affects the optimal development of CRVs, suggesting that Vamp7 mediates fusion events that are required for the biogenesis of CRVs. Indeed, we have observed that overexpression of Vamp7 NT inhibited the heterotypic fusion with lysosomes and the homotypic fusion between individual Coxiella phagosomes and CRVs. Moreover, we have detected in the vacuole membrane, at different infection times, the Vamp7 partners (Vti1a and Vti1b). Interestingly, treatment with chloramphenicol reduced the colocalization between C.burnetii and Vamp7, Vti1a or Vti1b, indicating that the recruitment of these SNAREs proteins is a bacteria-driven process that favours the CRV biogenesis, likely by facilitating the interaction with the endolysosomal compartment. © 2012 John Wiley & Sons Ltd.

Griselda C.M.,National University of Cuyo
Neuroscience and Biobehavioral Reviews | Year: 2011

Glucocorticoids (GC) are necessary for normal life but elevated levels of GC have been implicated in the development of several neurological diseases and psychiatric disorders. Nowadays, it is well known that high levels of GC in the central nervous system (CNS) generate an increase in the production of reactive oxygen species (ROS), derived mainly from the nitric oxide (NO) pathway. Accordingly, there is an increase of l-arginine (l-Arg.) availability. This report reviews the evidence that d-arginine (d-Arg.) induces normalization of l-Arg. resulting in protection against GC neurotoxic actions in the hippocampus. It is important to highlight that this D-amino acid does not interfere with the expected peripheral effects of GC such as suppression of the hypothalamic-pituitary-adrenal axis (HPA axis) and the immune response, commonly used in clinical practice. © 2011 Elsevier Ltd.

Inis Biotech Llc, Conicet and National University of Cuyo | Date: 2015-04-07

Process for obtaining lithium compounds and intermediate compounds, comprising the following steps: a) contacting aluminosilicate particles, for example -spodumene, with at least one fluorine compound, for example HF, NaF or others; b) stirring the mixture increasing the temperature until reaching an appropriate temperature; c) carrying out at least a precipitation and filtration process of the mixture of step b), and, d) recovering the lithium compound. The process may comprise using HF at a concentration between 5 and 30% v/v or NaF at a concentration between 5 and 30% w/v; a solid/liquid ratio of step a) between 0.9 and 14.4% w/v; a particle size of between 29 and 200 m. The final lithium product of the process may be lithium carbonate or lithium fluoride.

Mestre M.B.,National University of Cuyo | Colombo M.I.,National University of Cuyo
PLoS Pathogens | Year: 2012

Staphylococcus aureus is a microorganism that causes serious diseases in the human being. This microorganism is able to escape the phagolysosomal pathway, increasing intracellular bacterial survival and killing the eukaryotic host cell to spread the infection. One of the key features of S. aureus infection is the production of a series of virulence factors, including secreted enzymes and toxins. We have shown that the pore-forming toxin α-hemolysin (Hla) is the S. aureus-secreted factor responsible for the activation of the autophagic pathway and that this response occurs through a PI3K/Beclin1-independent form. In the present report we demonstrate that cAMP has a key role in the regulation of this autophagic response. Our results indicate that cAMP is able to inhibit the autophagy induced by Hla and that PKA, the classical cAMP effector, does not participate in this regulation. We present evidence that EPAC and Rap2b, through calpain activation, are the proteins involved in the regulation of Hla-induced autophagy. Similar results were obtained in cells infected with different S. aureus strains. Interestingly, in this report we show, for the first time to our knowledge, that both EPAC and Rap2b are recruited to the S. aureus-containing phagosome. We believe that our findings have important implications in understanding innate immune processes involved in intracellular pathogen invasion of the host cell. © 2012 Mestre, Colombo.

Tomes C.N.,National University of Cuyo
Biochemical Journal | Year: 2015

Exocytosis is a highly regulated process that consists of multiple functionally, kinetically and/or morphologically definable stages such as recruitment, targeting, tethering and docking of secretory vesicles with the plasma membrane, priming of the fusion machinery and calcium-triggered membrane fusion. After fusion, the membrane around the secretory vesicle is incorporated into the plasma membrane and the granule releases its contents. The proteins involved in these processes belong to several highly conserved families: Rab GTPases, SNAREs (soluble NSF-attachment protein receptors), α-SNAP (α-NSF attachment protein), NSF (N-ethylmaleimide-sensitive factor), Munc13 and -18, complexins and synaptotagmins. In the present article, the molecules of exocytosis are reviewed, using human sperm as a model system. Sperm exocytosis is driven by isoforms of the same proteinaceous fusion machinery mentioned above, with their functions orchestrated in a hierarchically organized and unidirectional signalling cascade. In addition to the universal exocytosis regulator calcium, this cascade includes other second messengers such as diacylglycerol, inositol 1,4,5-trisphosphate and cAMP, as well as the enzymes that synthesize them and their target proteins. Of special interest is the cAMP-binding protein Epac (exchange protein directly activated by cAMP) due in part to its enzymatic activity towards Rap. The activation of Epac and Rap leads to a highly localized calcium signal which, together with assembly of the SNARE complex, governs the final stages of exocytosis. The source of this releasable calcium is the secretory granule itself. © The Authors Journal compilation © 2015 Biochemical Society.

The transport properties of ultra-thin SrTiO(3) (STO) layers grown over YBa(2)Cu(3)O(7) electrodes were studied by conductive atomic force microscopy at the nano-scale. A very good control of the barrier thickness was achieved during the deposition process. A phenomenological approach was used to obtain critical parameters regarding the structural and electrical properties of the system. The STO layers present an energy barrier of 0.9 eV and an attenuation length of 0.23 nm, indicating very good insulating properties for the development of high-quality Josephson junctions.

Vazquez C.L.,National University of Cuyo | Colombo M.I.,National University of Cuyo
Cell Death and Differentiation | Year: 2010

Coxiella burnetii is the etiological agent of the human disease, Q fever, and is an obligate intracellular bacterium that invades and multiplies in a vacuole with lysosomal characteristics. We have previously shown that Coxiella interacts with the autophagic pathway as a strategy for its survival and replication. In addition, recent studies have shown that Coxiella exerts anti-apoptotic activity to maintain the host cell viability, thus generating a persistent infection. In the present report, we have explored the role of Beclin 1 and Bcl-2 in C. burnetii infection to elucidate how this bacterium modulates autophagy and apoptosis to its own benefit. Beclin 1, a Bcl-2 interacting protein, is required for autophagy. In this study, we show that Beclin 1 is recruited to the Coxiella-membrane vacuole, favoring its development and bacterial replication. In contrast, the anti-apoptotic protein Bcl-2 alters the normal development of the Coxiella-replicative compartment, in spite of also being recruited to the vacuole membrane. Furthermore, both vacuole development and the anti-apoptotic effect of C. burnetii are affected by Beclin 1 depletion and by the expression of a Beclin 1 mutant defective in Bcl-2 binding. Overall, these findings indicate that C. burnetii infection modulates autophagy and apoptotic pathways through Beclin 1/Bcl-2 interplay to establish a successful infection in the host cell. © 2010 Macmillan Publishers Limited. All rights reserved.

Renna N.F.,National University of Cuyo
Mediators of inflammation | Year: 2013

The objective of this work was to demonstrate the role of COX-2 enzyme at the vascular in experimental model of metabolic syndrome. SHR male WKY rats were employed; they were distributed in 8 groups (n = 8 each): control (W); W + L: WKY rats receiving 20 mg/kg of lumiracoxib by intraesophageal administration; SHR; SHR + L: SHR + 20 mg/kg of lumiracoxib by intraesophageal administration; Fructose-Fed Rats (FFR): WKY rats receiving 10% (w/v) fructose solution in drinking water during all 12 weeks; FFR + L: FFR + 20 mg/kg of lumiracoxib by intraesophageal administration; Fructose-Fed Hypertensive Rats (FFHR): SHR receiving 10% (w/v) fructose solution in drinking water during all 12 weeks; and FFHR + L: FFHR + 20 mg/kg of lumiracoxib by intraesophageal administration. Metabolic variables, blood pressure, morphometric variables, and oxidative stress variables were evaluated; also MMP-2 and MMP-9 (collagenases), VCAM-1, and NF- κ B by Westernblot or IFI were evaluated. FFHR presented all variables of metabolic syndrome; there was also an increase in oxidative stress variables; vascular remodeling and left ventricular hypertrophy were evidenced along with a significant increase in the expression of the mentioned proinflammatory molecules and increased activity and expression of collagenase. Lumiracoxib was able to reverse vascular remodeling changes and inflammation, demonstrating the involvement of COX-2 in the pathophysiology of vascular remodeling in this experimental model.

Curadelli O.,National University of Cuyo
Journal of Constructional Steel Research | Year: 2013

Seismic performance of cylindrical liquid storage tanks base-isolated by bilinear bearings is investigated. The paper displays a stochastic parametrical study in which three design parameters, namely isolation period, yield strength and viscous damping ratio, characterizing the isolation system are taken into consideration. The earthquake excitation, modeled as a stationary random process, is characterized by a power spectral density function calculated via a compatible seismic design spectrum. The stochastic response of the base-isolated cylindrical tanks is obtained by the convolution between the frequency response function of the system and the input power spectrum. To determine effective damping and stiffness coefficients corresponding to the equivalent linear system a statistical linearization scheme was used. For the purpose of evaluating the seismic behavior under different conditions, two liquid levels (aspect ratios) and soil types (soft and stiff soil) were considered. Thus, the study demonstrates the influence of each characteristic parameter of the isolation system and soil conditions on the response of cylindrical base-isolated tanks and principally allows visualizing the seismic performance that can be achieved through the selection of those parameters under certain soil conditions. Further, it is confirmed that soft soil conditions amplify the overall response of the system specially the base and sloshing displacements, as well as the normalized base shear to a lesser extent. © 2013 Elsevier Ltd.

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