431 research outputs found

    Micro RNA: New aspect in pathobiology of preeclampsia?

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    The discovery of miRNA in 1993, by Ambros et al. has had a huge influence in pathogenesis theory; diagnosis and treatment approach to some diseases. Some scientifically proven theories have been proposed to seek the association of alterations of miRNA expression to incidences and severity of preeclampsia (PE). In this review we explore the result of such investigations that discuss the association of miRNA and PE along with the role of various mRNAs in PE pathogenesis.Keywords: Preeclampsia; MicroRNA; miRNA; Preeclampsia pathogenesi

    Adaptive Reconfiguration of Natural Killer Cells in HIV-1 Infection

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    Human cytomegalovirus (HCMV) co-infection is highly prevalent within HIV-1 cohorts and is an important cofactor in driving ongoing immune activation, even during effective antiretroviral treatment. HCMV infection has recently been associated with expansion of adaptive-like natural killer (NK) cells, which harbor epigenetic alterations that impact on their cellular function and phenotype. The influence of HCMV co-infection on the considerable heterogeneity among NK cells and their functional responses to different stimuli was assessed in a cohort of HIV-1-infected individuals sampled during different stages of infection, compared with healthy subjects stratified according to HCMV serostatus. Our data demonstrate a reshaping of the NK cell pool in HIV-1 infection of HCMV-seropositive individuals, with an accentuated peripheral transition of CD56dim NK cells toward a mature CD57+ CD85j+ NKG2C+ NKG2A− phenotype. Lack of PLZF further distinguishes adaptive NK cells from other NK cells expressing CD57 or NKG2C. PLZF− NK cells from HIV-infected individuals had high expression of CD2, were Siglec-7 negative and exhibited downregulation of key signaling molecules, SYK and FcεRI-γ, overwhelmingly displaying features of adaptive NK cells that correlated with HCMV serum Ab levels. Notably this adaptive-like signature was detected during early HIV-1 infection and persisted during treatment. Adaptive-like NK cell subsets in HIV-1-infected individuals displayed enhanced IFN-γ production following Fc receptor triggering compared with their conventional NK cell counterparts, and their ability to produce TNF-α and degranulate was preserved. Together, these data suggest that HMCV infection/reactivation, a hallmark of HIV-1 infection, plays a role in driving a relative expansion of NK cells with adaptive features during HIV-1 infection. The identification of selective NK subsets with retained effector activity in HIV-1-infected subjects raises the possibility of developing therapeutic strategies that exploit specific NK subpopulations to achieve better HIV-1 control

    Varied effects of algal symbionts on transcription factor NF-κB in a sea anemone and a coral: possible roles in symbiosis and thermotolerance

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    Many cnidarians, including the reef-building corals, undergo symbiotic mutualisms with photosynthetic dinoflagellate algae of the family Symbiodiniaceae. These partnerships are sensitive to temperature extremes, which cause symbiont loss and increased coral mortality. Previous studies have implicated host immunity and specifically immunity transcription factor NF-κB as having a role in the maintenance of the cnidarian-algal symbiosis. Here we have further investigated a possible role for NF-κB in establishment and loss of symbiosis in various strains of the anemone Exaiptasia (Aiptasia) and in the coral Pocillopora damicornis. Our results show that NF-κB expression is reduced in Aiptasia larvae and adults that host certain algae strains. Treatment of Aiptasia larvae with a known symbiosis-promoting cytokine, transforming growth factor β, also led to decreased NF-κB expression. We also show that aposymbiotic Aiptasia (with high NF-κB expression) have increased survival following infection with the pathogenic bacterium Serratia marcescens as compared to symbiotic Aiptasia (low NF-κB expression). Furthermore, a P. damicornis coral colony hosting Durusdinium spp. (formerly clade D) symbionts had higher basal NF-κB expression and decreased heat-induced bleaching as compared to two individuals hosting Cladocopium spp. (formerly clade C) symbionts. Lastly, genome-wide gene expression profiling and genomic promoter analysis identified putative NF-κB target genes that may be involved in thermal bleaching, symbiont maintenance, and/or immune protection in P. damicornis. Our results provide further support for the hypothesis that modulation of NF-κB and immunity plays a role in some, but perhaps not all, cnidarian-Symbiodiniaceae partnerships as well as in resistance to pathogens and bleaching.Accepted manuscrip

    Naturaleza internacional del arbitraje. Ley 1563 de 2012

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    El arbitraje es un mecanismo alternativo de solución de conflictos (MASC) mediante el cual las partes/resuelven sus diferencias ante un tribunal independiente, es decir, difieren a árbitros2. La solución de una controversia relativa a asuntos de libre disposición o aque­llos que la ley autoriza. El arbitraje se rige a través de los principios de imparcialidad, ido­neidad, celeridad, igualdad, oralidad, publi­cidad y contradicción. Es un mecanismo hetero-compositivo, toda vez que es un tercero diferente a las partes quien se encarga de dirimir el conflicto; es oneroso, ya que se deben pagar los honora­rios y gastos del tribunal para que se pueda adelantar el trámite; es excepcional, ya que las partes a través de un pacto arbitral han rechazado acudir a la justicia ordinaria para acudir a este mecanismo alternativo para solucionar su confrontación -si el pacto está contenido en una cláusula esta es autónoma del contrato-; es temporal dado que el tribu­nal cesa sus funciones cuando se presentan diversas causales como la expedición del lau­do, vencimiento de termino, etc

    Systematic investigation of a family of gradient-dependent functionals for solids

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    Eleven density functionals are compared with regard to their performance for the lattice constants of solids. We consider standard functionals, such as the local-density approximation and the Perdew-Burke-Ernzerhof (PBE) generalized-gradient approximation (GGA), as well as variations of PBE GGA, such as PBEsol and similar functionals, PBE-type functionals employing a tighter Lieb-Oxford bound, and combinations thereof. Several of these variations are proposed here for the first time. On a test set of 60 solids we perform a system-by-system analysis for selected functionals and a full statistical analysis for all of them. The impact of restoring the gradient expansion and of tightening the Lieb-Oxford bound is discussed, and confronted with previous results obtained from other codes, functionals or test sets. No functional is uniformly good for all investigated systems, but surprisingly, and pleasingly, the simplest possible modifications to PBE turn out to have the most beneficial effect on its performance. The atomization energy of molecules was also considered and on a testing set of six molecules, we found that the PBE functional is clearly the best, the others leading to strong overbinding

    Molecular Pathogenesis of Preeclampsia: MicroRNA Hypothesis

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    The discovery of micro RNA (miRNA) in 1993 by Ambros and colleagues has a huge influence in pathogenesis theory, diagnosis and treatment approach of some diseases. Some studies have conducted to seek the association alterations of miRNA expression to incidences and severity of preeclampsia (PE). We have reviewed some studies that conducted to seek the association of miRNA and PE and we discussed the role of various miRNAs in PE pathogenesis. In summary, we have shown that many researchers have given evident that the different placental and plasma miRNA expression is associated with PE. Some studies also identified the novel candidate of miRNAs (and their pathways) that may be of etiologic relevance in the pathogenesis of PE. Base on review, specific miRNA have a role to down regulate of anti apoptosis genes, regulate angiogenics growth factors such as angiogenin, vascular endothelial growth factor (VEGF) B (VEGF-β), cysteine-rich 61 (CYR61), Placental growth factor (PlGF) and VEGF-A that have a role in angiogenesis. miRNA also have a role in survival, migration, and capillary tube formation of HUVEC by targeted of c-kit. Some miRNAs target genes that participate in immunologic dysfunction, cell adhesion, cell cycle, and signaling. miRNA also have a roles in endothelial cell response to hypoxia, cell differentiation, and survival. A miRNA influence calcium signaling through negative regulations of the calmodulin-coding mRNAs, Mef2a and Gata4, mainly in smooth muscle cells that contribute to PE pathogenesis. These investigations provide novel targets for further investigation of the pathogenesis of PE and these differential miRNAs may be potential markers for the diagnosis and provide a potential therapeutic target for PE. Further investigations on posttranscriptional regulation in PE to evaluate biologic effects of identified miRNAs (including confirmations of miRNA and target gene interactions) are neede

    An AFM Approach of RBC Micro and Nanoscale Topographic Features During Storage

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    Blood gamma irradiation is the only available method to prevent transfusion-associated graft versus host disease (TA-GVHD). However, when blood is irradiated, determine blood shelf time is crucial. Non-irradiated blood has a self-time from 21 to 35 days when is preserved with an anticoagulated solution and stored at 4°C. During their storage, red blood cells (RBC) undergo a series of biochemical, biomechanical and molecular changes involving what is known as storage lesion (SL). SL include loss of structural integrity of RBC, a decrease of 2,3-diphosphatidylglyceric acid levels, and an increase of both ion potassium concentration and hemoglobin (Hb). On the other hand, Atomic force Microscopy (AFM) represents a versatile tool for a nano-scale high-resolution topographic analysis in biological systems. In order to evaluate SL in irradiated and non-irradiated blood, RBC topography and morphometric parameters were obtained from an AFM XE-BIO system. Cell viability was followed using flow cytometry. Our results showed that early markers as nanoscale roughness, allow us to evaluate blood quality since another perspective

    Floating stones off El Hierro, Canary Islands: xenoliths of pre-island sedimentary origin in the early products of the October 2011 eruption

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    The eruption that started off the south coast of El Hierro, Canary Islands, in October 2011 has emitted intriguing eruption products found floating in the sea. These specimens appeared as floating volcanic "bombs" that have in the meantime been termed "restingolites" (after the close-by village of La Restinga) and exhibit cores of white and porous pumice-like material. Currently the nature and origin of these "floating stones" is vigorously debated among researchers, with important implications for the interpretation of the hazard potential of the ongoing eruption. The "restingolites" have been proposed to be either (i) juvenile high-silica magma (e.g. rhyolite), (ii) remelted magmatic material (trachyte), (iii) altered volcanic rock, or (iv) reheated hyaloclastites or zeolite from the submarine slopes of El Hierro. Here, we provide evidence that supports yet a different conclusion. We have collected and analysed the structure and composition of samples and compared the results to previous work on similar rocks found in the archipelago. Based on their high silica content, the lack of igneous trace element signatures, and the presence of remnant quartz crystals, jasper fragments and carbonate relicts, we conclude that "restingolites" are in fact xenoliths from pre-island sedimentary rocks that were picked up and heated by the ascending magma causing them to partially melt and vesiculate. They hence represent messengers from depth that help us to understand the interaction between ascending magma and crustal lithologies in the Canary Islands as well as in similar Atlantic islands that rest on sediment/covered ocean crust (e.g. Cape Verdes, Azores). The occurrence of these "restingolites" does therefore not indicate the presence of an explosive high-silica magma that is involved in the ongoing eruption

    Separation of the Exchange-Correlation Potential into Exchange plus Correlation: an Optimized Effective Potential Approach

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    Most approximate exchange-correlation functionals used within density functional theory are constructed as the sum of two distinct contributions for exchange and correlation. Separating the exchange component from the entire functional is useful since, for exchange, exact relations exist under uniform density scaling and spin scaling. In the past, accurate exchange-correlation potentials have been generated from essentially exact densities constructed using information from either quantum chemistry or quantum Monte Carlo calculations but they have not been correctly decomposed into their separate exchange and correlation components, except for two-electron systems. exchange and correlation components (except for two-electron systems). Using a recently proposed method, equivalent to the solution of an optimized effective potential problem with the corresponding orbitals replaced by the exact Kohn-Sham orbitals, we obtain the separation according to the density functional theory definition. We compare the results for the Ne and Be atoms with those obtained by the previously used approximate separation scheme
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