125 research outputs found

    Neogene paleoceanography of the eastern equatorial Pacific based on the radiolarian record of IODP drill sites off Costa Rica

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    The Integrated Ocean Drilling Program (IODP) Expedition 344 drilled cores following a transect across the convergent margin off Costa Rica. Two of the five sites (U1381 and U1414) are the subject of the present study. Major radiolarian faunal breaks and characteristic species groups were defined with the aid of cluster analysis, nodal analysis, and discriminant analysis of principal components. A middle-late Miocene to Pleistocene age (radiolarian zones RN5 to RN16) was determined for the sites, which agrees with the nannofossil zonations and 40Ar/39Ar and tephra layers. Considering the northward movement of the Cocos plate (∼7.3 cm/yr), and a paleolatitude calculator, it is assumed that during the Miocene the two sites were located ∼1000 km to the southwest of their current position, slightly south of the equator. The radiolarian faunas retrieved were thus seemingly formed under the influence of different oceanic currents and sources of nutrients. Changes in the radiolarian assemblages at Site U1414 point at dissimilar environmental settings associated with the colder South Equatorial Current and the warmer Equatorial Countercurrent, as well as to coastal upwelling. These differences are best reflected by changes in the abundance of the morphotype Spongurus spp., with noticeably higher values during the Miocene, than in the Pliocene and the Pleistocene. Because Spongurus spp. is generally associated with cooler waters, these abundance variations (as well as those of several other species) suggest that during the Miocene the area had a stronger influence of colder waters than during younger periods. During the Pliocene and the lowermost Pleistocene, biogenic remains are scarce, presumably due to the terrigenous input, which could have diluted and affected the preservation of pelagic fossils, as well as to the displacement of the site to warmer waters. A typically tropical fauna characterized the Pleistocene, yet with widespread presence of colder water species, most probably indicative of the influence of coastal upwelling processes.Fil: Sandoval, María I.. Universidad de Costa Rica; Costa Rica. Universite de Lausanne; SuizaFil: Boltovskoy, Demetrio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Baxter, Alan T.. University of New England; Australia. McGill University; CanadáFil: Baumgartner, Peter O.. Universite de Lausanne; Suiz

    Distribution of the transposable elements bilbo and gypsy in original and colonizing populations of Drosophila subobscura

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    Background: Transposable elements (TEs) constitute a substantial amount of all eukaryotic genomes. They induce an important proportion of deleterious mutations by insertion into genes or gene regulatory regions. However, their mutational capabilities are not always adverse but can contribute to the genetic diversity and evolution of organisms. Knowledge of their distribution and activity in the genomes of populations under different environmental and demographic regimes, is important to understand their role in species evolution. In this work we study the chromosomal distribution of two TEs, gypsy and bilbo, in original and colonizing populations of Drosophila subobscura to reveal the putative effect of colonization on their insertion profile. Results: Chromosomal frequency distribution of two TEs in one original and three colonizing populations of D. subobscura, is different. Whereas the original population shows a low insertion frequency in most TE sites, colonizing populations have a mixture of high (frequency ≥ 10%) and low insertion sites for both TEs. Most highly occupied sites are coincident among colonizing populations and some of them are correlated to chromosomal arrangements. Comparisons of TE copy number between the X chromosome and autosomes show that gypsy occupancy seems to be controlled by negative selection, but bilbo one does not. Conclusion: These results are in accordance that TEs in Drosophila subobscura colonizing populations are submitted to a founder effect followed by genetic drift as a consequence of colonization. This would explain the high insertion frequencies of bilbo and gypsy in coincident sites of colonizing populations. High occupancy sites would represent insertion events prior to colonization. Sites of low frequency would be insertions that occurred after colonization and/or copies from the original population whose frequency is decreasing in colonizing populations. This work is a pioneer attempt to explain the chromosomal distribution of TEs in a colonizing species with high inversion polymorphism to reveal the putative effect of arrangements in TE insertion profiles. In general no associations between arrangements and TE have been found, except in a few cases where the association is very strong. Alternatively, founder drift effects, seem to play a leading role in TE genome distribution in colonizing populations

    Solvents derived from glycerol modify classical regioselectivity in the enzymatic synthesis of disaccharides with Biolacta β-galactosidase

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    Green solvents made from glycerol change the classical regioselectivity of Biolacta No 5 β-galactosidase, from β(1→4) to β(1→6) linkages when a 2 M concentration was used. In order to explain these results, the non-proteic compounds present in the Biolacta preparation were separated by precipitation with ammonium sulfate and the remaining protein extract was used to set reactions with appropriate organic solvents to find that the regioselectivity towards the β(1→6) isomer is retained. According to proteomic analysis, a 98% homology between Streptococcus pneumoniae and Biolacta β-galactosidase preparation was found. With these data, molecular modelling was done which predicts a tridimensional interaction in the enzyme active site with the donor (GlcNAc) and the water-solvent mixture which explains this phenomenon. © 2011 The Royal Society of Chemistry.This work was supported by two research projects of the Spanish MICINN (Ministerio de Ciencia e Innovación de España) CTQ2009-11801 and CTQ2008-05138, and one European project (FP-62003-NMP-SMF-3, proposal 011774-2).Peer Reviewe

    Non-invasive Mechanism Classification and Localization in Supraventricular Cardiac Arrhythmias

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    [EN] In this study, we investigated the most relevant biomarkers for noninvasive classification and mechanism location in atrial tachycardia (AT), flutter (AFL) and fibrillation (AF). Biomarkers were calculated using noninvasive body surface (BSPM) dominant frequency and phase maps. We used 19 simulations of 567 to 64-lead BSPMs, from which were extracted 32 biomarkers. Biomarker ranking was performed with ANOVA, Kendall and Lasso techniques. The best four biomarkers were identified and used to classify the arrhythmias in all combinations, and the best two used for noninvasive driver localization. Arrhythmia classification accuracy was 94.74%. The feature combination which best distinguish AF from non-AF were mean filament displacement and mean OI, while those that best distinguish AFL from AT were mean and SD of SP distribution. There was good agreement across ranking techniques. Mechanism location accuracy was 78.95%, with the most important biomarkers being percentage SPs within each torso division, and SD of filament histogram cluster area. This study highlights that organization related features well identifies AF and spatial SP distribution discriminate AT from AFL and also it¿s localization.VGM is funded by the European Union's Horizon 2020 research and innovation programme under the Marie Skodowska-Curie grant agreement No. 860974. IS, JAS and JS are supported by grant #2018/25606-2, Sao Paulo Research Foundation (FAPESP).Sandoval, I.; Marques, VG.; Sims, JA.; Rodrigo, M.; Guillem Sánchez, MS.; Salinet, J. (2021). Non-invasive Mechanism Classification and Localization in Supraventricular Cardiac Arrhythmias. 1-4. https://doi.org/10.22489/CinC.2021.2261

    AB0690 Antiphospholipid antibodies and spondyloarthritis. Truth or myth? Our results in a third level hospital

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    [EN] The importance of antiphospholipid antibodies and their clinical involvement in thrombotic phenomena, isolated or associated with certain autoimmune diseases such as systemic lupus erythematosus, is known. However, in spondyloarthritis (SpA) there is little published data about it.S

    Functional relevance of the switch of VEGF receptors/co-receptors during peritoneal dialysis-induced mesothelial to mesenchymal transition

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    Vascular endothelial growth factor (VEGF) is up-regulated during mesothelial to mesenchymal transition (MMT) and has been associated with peritoneal membrane dysfunction in peritoneal dialysis (PD) patients. It has been shown that normal and malignant mesothelial cells (MCs) express VEGF receptors (VEGFRs) and co-receptors and that VEGF is an autocrine growth factor for mesothelioma. Hence, we evaluated the expression patterns and the functional relevance of the VEGF/VEGFRs/co-receptors axis during the mesenchymal conversion of MCs induced by peritoneal dialysis. Omentum-derived MCs treated with TGF-β1 plus IL-1β (in vitro MMT) and PD effluent-derived MCs with non-epithelioid phenotype (ex vivo MMT) showed down-regulated expression of the two main receptors Flt-1/VEGFR-1 and KDR/VEGFR-2, whereas the co-receptor neuropilin-1 (Nrp-1) was up-regulated. The expression of the Nrp-1 ligand semaphorin-3A (Sema-3A), a functional VEGF competitor, was repressed throughout the MMT process. These expression pattern changes were accompanied by a reduction of the proliferation capacity and by a parallel induction of the invasive capacity of MCs that had undergone an in vitro or ex vivo MMT. Treatment with neutralizing anti-VEGF or anti-Nrp-1 antibodies showed that these molecules played a relevant role in cellular proliferation only in naïve omentum-derived MCs. Conversely, treatment with these blocking antibodies, as well as with recombinant Sema-3A, indicated that the switched VEGF/VEGFRs/co-receptors axis drove the enhanced invasion capacity of MCs undergoing MMT. In conclusion, the expression patterns of VEGFRs and co-receptors change in MCs during MMT, which in turn would determine their behaviour in terms of proliferation and invasion in response to VEGFThis work was supported by grant SAF2010-21249 from the ‘‘Ministerio de Economía y Competitividad’’ to M.L.C. and by grant S2010/BMD-2321 from ‘‘Comunidad Autónoma de Madrid’’ to M.L.C. and R.S. This work was also partially supported by grants PI 09/0776 from ‘‘Fondo de Investigaciones Sanitarias’’ to A.A., and RETICS 06/0016 (REDinREN, Fondos FEDER, EU) to R.S

    Glutaminase and MMP-9 downregulation in cortex and hippocampus of LPA1 receptor null mice correlate with altered dendritic spine plasticity

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    Lysophosphatidic acid (LPA) is an extracellular lipid mediator that regulates nervous system development and functions acting through G protein-coupled receptors (GPCRs). Here we explore the crosstalk between LPA1 receptor and glutamatergic transmission by examining expression of glutaminase (GA) isoforms in different brain areas isolated from wild-type (WT) and KOLPA1 mice. Silencing of LPA1 receptor induced a severe down-regulation of Gls-encoded long glutaminase protein variant (KGA) (glutaminase gene encoding the kidney-type isoforms, GLS) protein expression in several brain regions, particularly in brain cortex and hippocampus. Immunohistochemical assessment of protein levels for the second type of glutaminase (GA) isoform, glutaminase gene encoding the liver-type isoforms (GLS2), did not detect substantial differences with regard to WT animals. The regional mRNA levels of GLS were determined by real time RT-PCR and did not show significant variations, except for prefrontal and motor cortex values which clearly diminished in KO mice. Total GA activity was also significantly reduced in prefrontal and motor cortex, but remained essentially unchanged in the hippocampus and rest of brain regions examined, suggesting activation of genetic compensatory mechanisms and/or post-translational modifications to compensate for KGA protein deficit. Remarkably, Golgi staining of hippocampal regions showed an altered morphology of glutamatergic pyramidal cells dendritic spines towards a less mature filopodia-like phenotype, as compared with WT littermates. This structural change correlated with a strong decrease of active matrix-metalloproteinase (MMP) 9 in cerebral cortex and hippocampus of KOLPA1 mice. Taken together, these results demonstrate that LPA signaling through LPA1 influence expression of the main isoenzyme of glutamate biosynthesis with strong repercussions on dendritic spines maturation, which may partially explain the cognitive and learning defects previously reported for this colony of KOLPA1 mice

    Impact of COVID-19 pandemic on cardiometabolic patients without SARS CoV-2 infection in Latin America

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    A cross-sectional survey including 38 questions about demography, clinical condition, changes in health habits, and medical treatments for cardiometabolic patients in outpatient follow-up was conducted. From June 15 to July 15, 2020, a total of 13 Latin-American countries participated in enrolling patients. These countries were divided into 3 geographic regions: Region 1 including North, Central, and Caribbean Regions (NCCR), Region 2 including the Andean Region (AR), and Region 3 including the Southern Cone Region (SCR). 4.216 patients were analyzed, resulting in a coefficient of 33.82%, 32.23%, and 33.94% for NCCR, AR, and SCR, respectively. Significant differences were found between the AR, SCR, and NCCR regions. The analysis of habitual medication usage showed that discontinued use of medication was more present in AR, reaching almost 30% (p < 0.001). The main finding of this study was the negative impact that restrictive measures have on adherence to medications and physical activity: Rs = 0.84 (p = 0.0003) and Rs = 0.61 (p = 0.0032), respectively. AR was the most vulnerable region. Restrictive quarantine measures imposed by the different countries showed a positive correlation with medication discontinuation and a negative correlation with physical activity levels in patients analyzed. These findings characterize the impact of the consequences left by this pandemic. Undoubtedly, restrictive measures have been and will continue to have reverberating negative effects in most Latin-American countries.Fil: Camiletti, Jorge. Hospital Italiano de La Plata; ArgentinaFil: Renna, Nicolas Federico. 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. Cátedra de Fisiología Patológica; Argentina. Hospital Español de Mendoza; ArgentinaFil: López Santi, Ricardo. Hospital Italiano de La Plata; ArgentinaFil: Erriest, Juan. Hospital Italiano de La Plata; ArgentinaFil: García-Bello, Eliomar. Centro de Diagnóstico Medicina Avanzada y Telemedicina; República DominicanaFil: Araujo, John. Centro Cardiovascular Somer Incare; ColombiaFil: Varleta-Olivares, Paola. Hospital Dipreca; ChileFil: Gómez-Díaz, Eduardo. Hospital Metropolitano del Norte; VenezuelaFil: Ramírez, Gisselle. Medicina Cardiovascular Asociada; República DominicanaFil: Berni Betancourt, Ana. Sociedad interamericana de Cardiología; México. Consejo Interamericano de Electrocardiográfica y Arritmias; México. Hospital Ángeles Pedregal; MéxicoFil: Escalada Lesme, Gustavo. Centro Médico Nacional-Hospital Nacional Itaguá; ParaguayFil: Campos Alcántara, Lourdes V.. Consultorio de Lourdes Victoria Campos Alcántara; PerúFil: Moya Loor, Leonardo. Hospital Santa Margarita; EcuadorFil: Rey Benavente, Claudio. Hospital Arroyabe Pichanal; ArgentinaFil: Almonte, Claudia. Medicina Cardiovascular Asociada; República DominicanaFil: Cortez Sandoval, Maicol. Hospital Nacional Edgardo Rebagliti Martins; PerúFil: Alvarado Cuadros, María. Department of Cardiology, Institution; EcuadorFil: Rosario, Monica I.. Centro de Diagnóstico Medicina Avanzada y Telemedicina; República DominicanaFil: Gupta, Shyla. Queen’s University; CanadáFil: Ibarrola, Martin. Cardiovascular Center BV; ArgentinaFil: Baranchuk, Adrián. Kingston Health Sciences Centre; Canad
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