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Montevideo, Uruguay

Benaim G.,Institute Estudios Avanzados IDEA | Benaim G.,Central University of Venezuela | Pimentel A.A.,Central University of Venezuela | Felibertt P.,University of Carabobo | And 6 more authors.
Biochemical and Biophysical Research Communications | Year: 2016

The increase in the intracellular Ca2+ concentration ([Ca2+]i) is the key variable for many different processes, ranging from regulation of cell proliferation to apoptosis. In this work we demonstrated that the sphingolipid sphingosine (Sph) increases the [Ca2+]i by inhibiting the sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA), in a similar manner to thapsigargin (Tg), a specific inhibitor of this Ca2+ pump. The results showed that addition of sphingosine produced a release of Ca2+ from the endoplasmic reticulum followed by a Ca2+ entrance from the outside mileu. The results presented in this work support that this sphingolipid could control the activity of the SERCA, and hence sphingosine may participate in the regulation of [Ca2+]I in mammalian cells. © 2016 Elsevier Inc.

Botti H.,Instituto Pasteur Of Montevideo | Botti H.,Center for Free Radical and Biomedical Research | Moller M.N.,Center for Free Radical and Biomedical Research | Moller M.N.,University of the Republic of Uruguay | And 9 more authors.
Journal of Physical Chemistry B | Year: 2010

The fast reaction of •NO and O2 •- to give ONOO- has been extensively studied at irreversible conditions, but the reasons for the wide variations in observed forward rate constants (3.8 ≥ kf ≥ 20 × 109 M-1 s-1) remain unexplained. We characterized the diffusion-dependent aqueous (pH > 12) chemical equilibrium of the form •NO + O2 •- = ONOO- with respect to its dependence on temperature, viscosity, and [ONOO-] eq by determining [ONOO-]eq and [ •NO]eq. The equilibrium forward reaction rate constant (kf eq) has negative activation energy, in contrast to that found under irreversible conditions. In contradiction to the law of mass action, we demonstrate that the equilibrium constant depends on ONOO- concentration. Therefore, a wide range of kf eq values could be derived (7.5-21 × 109 M -1 s-1). Of general interest, the variations in k f can thus be explained by its dependence on the distance between ONOO- particles (sites of generation of •NO and O2 •-). © 2010 American Chemical Society.

Basika T.,University of the Republic of Uruguay | Munoz N.,University of the Republic of Uruguay | Casaravilla C.,University of the Republic of Uruguay | Irigoin F.,University of the Republic of Uruguay | And 7 more authors.
Parasitology | Year: 2012

Infection by larval Echinococcus granulosus is usually characterized by tight inflammatory control. However, various degrees of chronic granulomatous inflammation are also observed, reaching a high point in infection of cattle by the most prevalent parasite strain worldwide, which is not well adapted to this host species. In this context, epithelioid and multinucleated giant macrophages surround the parasite, and the secreted products of these cells often associate with the larval wall. The phagocyte-specific S100 proteins, S100A8, S100A9 and S100A12, are important non-conventionally secreted amplifiers of inflammatory responses. We have analysed by proteomics and immunohistochemistry the presence of these proteins at the E. granulosus larva-host interface. We found that, in the context of inflammatory control as observed in human infections, the S100 proteins are not abundant, but S100A9 and S100A8 can be expressed by eosinophils distal to the parasite. In the granulomatous inflammation context as observed in cattle infections, we found that S100A12 is one of the most abundant host-derived, parasite-associated proteins, while S100A9 and S100A8 are not present at similarly high levels. As expected, S100A12 derives mostly from the epithelioid and multinucleated giant cells. S100A12, as well as cathepsin K and matrix metalloproteinase-9, also expressed by E. granulosus-elicited epithelioid cells, are connected to the Th17 arm of immunity, which may therefore be involved in this granulomatous response. Copyright © 2012 Cambridge University Press.

Gonzalez-Recio O.,Instituto Nacional Of Investigaciones Agrarias | Weigel K.A.,University of Wisconsin - Madison | Gianola D.,University of Wisconsin - Madison | Gianola D.,Norwegian University of Life Sciences | And 2 more authors.
Genetics Research | Year: 2010

The L2-Boosting algorithm is one of the most promising machine-learning techniques that has appeared in recent decades. It may be applied to high-dimensional problems such as whole-genome studies, and it is relatively simple from a computational point of view. In this study, we used this algorithm in a genomic selection context to make predictions of yet to be observed outcomes. Two data sets were used: (1) productive lifetime predicted transmitting abilities from 4702 Holstein sires genotyped for 32 611 single nucleotide polymorphisms (SNPs) derived from the Illumina BovineSNP50 BeadChip, and (2) progeny averages of food conversion rate, pre-corrected by environmental and mate effects, in 394 broilers genotyped for 3481 SNPs. Each of these data sets was split into training and testing sets, the latter comprising dairy or broiler sires whose ancestors were in the training set. Two weak learners, ordinary least squares (OLS) and non-parametric (NP) regression were used for the L2-Boosting algorithm, to provide a stringent evaluation of the procedure. This algorithm was compared with BL [Bayesian LASSO (least absolute shrinkage and selection operator)] and BayesA regression. Learning tasks were carried out in the training set, whereas validation of the models was performed in the testing set. Pearson correlations between predicted and observed responses in the dairy cattle (broiler) data set were 065 (033), 053 (037), 066 (026) and 063 (027) for OLS-Boosting, NP-Boosting, BL and BayesA, respectively. The smallest bias and mean-squared errors (MSEs) were obtained with OLS-Boosting in both the dairy cattle (008 and 108, respectively) and broiler (0011 and 0006) data sets, respectively. In the dairy cattle data set, the BL was more accurate (bias=010 and MSE=110) than BayesA (bias=126 and MSE=281), whereas no differences between these two methods were found in the broiler data set. L2-Boosting with a suitable learner was found to be a competitive alternative for genomic selection applications, providing high accuracy and low bias in genomic-assisted evaluations with a relatively short computational time. © 2010 Cambridge University Press.

Ramirez J.C.,Institute Investigaciones en Ingenieria Genetica y Biologia Molecular | Cura C.I.,Institute Investigaciones en Ingenieria Genetica y Biologia Molecular | Da Cruz Moreira O.,Instituto Oswaldo Cruz Fiocruz | Lages-Silva E.,Federal University of Triangulo Mineiro | And 40 more authors.
Journal of Molecular Diagnostics | Year: 2015

An international study was performed by 26 experienced PCR laboratories from 14 countries to assess the performance of duplex quantitative real-time PCR (qPCR) strategies on the basis of TaqMan probes for detection and quantification of parasitic loads in peripheral blood samples from Chagas disease patients. Two methods were studied: Satellite DNA (SatDNA) qPCR and kinetoplastid DNA (kDNA) qPCR. Both methods included an internal amplification control. Reportable range, analytical sensitivity, limits of detection and quantification, and precision were estimated according to international guidelines. In addition, inclusivity and exclusivity were estimated with DNA from stocks representing the different Trypanosoma cruzi discrete typing units and Trypanosoma rangeli and Leishmania spp. Both methods were challenged against 156 blood samples provided by the participant laboratories, including samples from acute and chronic patients with varied clinical findings, infected by oral route or vectorial transmission. kDNA qPCR showed better analytical sensitivity than SatDNA qPCR with limits of detection of 0.23 and 0.70 parasite equivalents/mL, respectively. Analyses of clinical samples revealed a high concordance in terms of sensitivity and parasitic loads determined by both SatDNA and kDNA qPCRs. This effort is a major step toward international validation of qPCR methods for the quantification of T. cruzi DNA in human blood samples, aiming to provide an accurate surrogate biomarker for diagnosis and treatment monitoring for patients with Chagas disease. © 2015 American Society for Investigative Pathology and the Association for Molecular Pathology.

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