1,086 research outputs found

    De la deconstrucción de la identidad de género a la deconstrucción de la identidad sexual

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    A través de esta comunicación queremos poner de manifiesto las similitudes entre las definiciones de identidad de género y de identidad sexual en tanto que construcciones altamente normativas que nacen en el contexto socio-histórico-cultural. Las críticas feministas y constructivistas al concepto de identidad de género nos resultan útiles a la hora de analizar y deconstruir el de identidad sexual que en este trabajo de investigación se presenta no como expresión de un self esencial (y por lo tanto ahistórico e inmutable) sino como construcción que se da en el contexto histórico-cultural. En nuestro trabajo de investigación proponemos un acercamiento narrativo al fenómeno de la asunción de la identidad lésbica y de su incorporación en la más general identidad personal a través del estudio de las historias de vida de 8 mujeres lesbianas. Las narraciones autobiográficas recogidas se han analizado utilizando una versión adaptada de los indicadores del self de Bruner (1997). El análisis narrativo así realizado nos ha ofrecido la posibilidad de apreciar los cambios cognitivos, emocionales y conductuales que nuestras entrevistadas han experimentado a lo largo del proceso y que se reflejan en sus narraciones, así como el proceso activo de deconstrucción de los significados estigmatizados asociados a la identidad homosexual

    Placental Expression of CD100, CD72 and CD45 Is Dysregulated in Human Miscarriage

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    CONTEXT AND OBJECTIVE: The etiology of miscarriage is often multifactorial. One major cause, immunological rejection of the fetus, has not been clearly elucidated. Our aim was to establish whether the semaphorin CD100, its natural receptor CD72, and the glycoprotein CD45, implicated in immune mechanisms, are involved in pregnancy loss by examining their placental expression with real-time PCR, immunohistochemistry and western blotting techniques. PATIENTS: Placenta tissue from 72 Caucasian women undergoing surgical uterine evacuation due to early spontaneous pregnancy loss between the 8(th) and 12(th) week of gestation was divided into four groups based on miscarriage number. Gestational age-matched placentas from 18 healthy women without a history of miscarriage undergoing voluntary pregnancy termination were the control group. Placenta from 6 Caesarean deliveries performed at 38-40 weeks of gestation was also studied. RESULTS: CD100, CD72 and CD45 were expressed in placenta and exhibited different mRNA and protein levels in normal pregnancy and miscarriage. In particular, protein levels were highly dysregulated around 10 weeks of gestation in first and second miscarriage placentas. The CD100 soluble form was produced and immediately shed from placental tissue in all samples. CONCLUSIONS: Fetal CD100, CD72 and CD45 seem to play a role in miscarriage. The present data support the involvement of the fetal immune system in pregnancy maintenance as well as failure

    Cholera toxin inhibits IL-12 production and CD8α+ dendritic cell differentiation by cAMP-mediated inhibition of IRF8 function

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    Prior studies have demonstrated that cholera toxin (CT) and other cAMP-inducing factors inhibit interleukin (IL)-12 production from monocytes and dendritic cells (DCs). We show that CT inhibits Th1 responses in vivo in mice infected with Toxoplasma gondii. This correlated with low serum IL-12 levels and a selective reduction in the numbers of CD8α+ conventional DCs (cDCs) in lymphoid organs. CT inhibited the function of interferon (IFN) regulatory factor (IRF) 8, a transcription factor known to positively regulate IL-12p35 and p40 gene expression, and the differentiation of CD8α+ and plasmacytoid DCs (pDCs). Fluorescence recovery after photobleaching analysis showed that exposure to CT, forskolin, or dibutyryl (db) cAMP blocked LPS and IFN-γ–induced IRF8 binding to chromatin. Moreover, CT and dbcAMP inhibited the binding of IRF8 to the IFN-stimulated response element (ISRE)–like element in the mouse IL-12p40 promoter, likely by blocking the formation of ISRE-binding IRF1–IRF8 heterocomplexes. Furthermore, CT inhibited the differentiation of pDCs from fms-like tyrosine kinase 3 ligand–treated bone marrow cells in vitro. Therefore, because IRF8 is essential for IL-12 production and the differentiation of CD8α+ cDCs and pDCs, these data suggest that CT and other Gs-protein agonists can affect IL-12 production and DC differentiation via a common mechanism involving IRF8

    Characterization of the defective interaction between a subset of natural killer cells and dendritic cells in HIV-1 infection

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    In this study, we demonstrate that the in vitro interactions between a CD56neg/CD16pos (CD56neg) subset of natural killer (NK) cells and autologous dendritic cells (DCs) from HIV-1–infected viremic but not aviremic individuals are markedly impaired and likely interfere with the development of an effective immune response. Among the defective interactions are abnormalities in the process of reciprocal NK–DC activation and maturation as well as a defect in the NK cell–mediated editing or elimination of immature DCs (iDCs). Notably, the lysis of mature DCs (mDCs) by autologous NK cells was highly impaired even after the complete masking of major histocompatibility complex I molecules, suggesting that the defective elimination of autologous iDCs is at the level of activating NK cell receptors. In this regard, the markedly impaired expression/secretion and function of NKp30 and TNF-related apoptosis-inducing ligand, particularly among the CD56neg NK cell subset, largely accounts for the highly defective NK cell–mediated lysis of autologous iDCs. Moreover, mDCs generated from HIV-1 viremic but not aviremic patients are substantially impaired in their ability to secrete interleukin (IL)-10 and -12 and to prime the proliferation of neighboring autologous NK cells, which, in turn, fail to secrete adequate amounts of interferon-γ

    Avian influenza virus isolated in wild waterfowl in Argentina: Evidence of a potentially unique phylogenetic lineage in South America

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    Avian influenza (AI) viruses have been sporadically isolated in South America. The most recent reports are from an outbreak in commercial poultry in Chile in 2002 and its putative ancestor from a wild bird in Bolivia in 2001. Extensive surveillance in wild birds was carried out in Argentina during 2006-2007. Using RRT-PCR, 12 AI positive detections were made from cloacal swabs. One of those positive samples yielded an AI virus isolated from a wild kelp gull (Larus dominicanus) captured in the South Atlantic coastline of Argentina. Further characterization by nucleotide sequencing reveals that it belongs to the H13N9 subtype. Phylogenetic analysis of the 8 viral genes suggests that the 6 internal genes are related to the isolates from Chile and Bolivia. The analysis also indicates that a cluster of phylogenetically related AI viruses from South America may have evolved independently, with minimal gene exchange, from influenza viruses in other latitudes. The data produced from our investigations are valuable contributions to the study of AI viruses in South America.Centro de Estudios Parasitológicos y de Vectore

    Possible role of placental CD100, CD72 and CD45 molecules in human miscarriage

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    The precise mechanism for recurrent miscarriage is unclear. A lot of metabolic alterations are involved in the missed intercommunication between mother and its foetus, causing their reciprocal intolerance. The identification of new molecules involved in pregnancy loss represents the main objective of our study. We analysed the semaphorin CD100, its natural receptor CD72 and the glycoprotein CD45, physically and functionally associated to CD100 in the placental tissues from recurrent miscarriages by real-time PCR, western blotting and immunohistochemistry. Placental tissue was obtained during surgical uterine evacuation in 72 caucasian women with early spontaneous pregnancy loss between 8th and 12th week of gestation and classified in four groups defined as first, second, third and fourth miscarriages. Other two normal placental groups were recruited: a) first trimester placentas (n = 18), matched for gestational age with placentas from spontaneous pregnancy loss; b) third trimester placentas (n = 6) at 38-40 weeks of gestation. We demonstrated that CD72, CD45 and CD100 mRNA were detectable in placental tissues with different expression in normal and pathological conditions. In addition, we demonstrated that CD72 and CD45 molecules were expressed in foetal macrophages and that their protein levels were especially deregulated in first and second miscarriages at about 10 weeks of gestation. On the contrary, CD100 cleaved protein appeared to be absent in placenta. In conclusion, our findings underline a possible role for CD100, CD72 and CD45 molecules in recurrent miscarriages, showing an important foetal involvement in the occurring of pregnancy loss

    Wild pigs and their widespread threat to biodiversity conservation in South America

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    Wild pigs, including wild boar (Sus scrofa) and feral domestic pig (Sus scrofa domestica), are associated with negative impacts in their native and introduced ranges. We compiled wild pig occurrence reports and utilized Maximum Entropy modelling to predict their potential distribution in ecoregions overlaying Argentina, Brazil, Bolivia, Chile, Uruguay and Paraguay. An analysis of their observed and potential distributions was carried out in relation to four biodiversity hotspots and 3766 protected areas to estimate the number of units and percent area currently and potentially invaded. Among biodiversity hotspots, Atlantic Forest, Cerrado, and Chilean Winter Rainfall-Valdivian Forests included 44.7% of wild pig records. The proportion of suitable area was 85% in Atlantic Forest, 61.3% in Cerrado, 37.5% in Chilean Winter Rainfall-Valdivian Forests, and 5.6% in Tropical Andes. The number of protected areas with known wild pig presence was led by Uruguay (100%), followed by Chile (20.3%), Argentina (15.8%), Paraguay (9.5%), Bolivia (6.5%), and Brazil (4.7%). The proportion of protected areas with predicted wild pig presence was highest in Uruguay (100%), followed by Paraguay (72.6%), Brazil (58.0%), Argentina (57.4%), Chile (42.2%), and Bolivia (35.9%). Our work represents the first assessment of wild pig potential distribution in South America and highlights the potentially devastating impacts of wild pigs on the regional biodiversity and national conservation targets, especially at mega-diverse areas. We present a dynamic web application that can be readily consulted by scientists, managers and decision makers to improve wild pig control and risk mitigation actions in the study region.Fil: la Sala, Luciano Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Burgos, Julian Mariano. Marine and Freshwater Research Institute; IslandiaFil: Caruso, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Bagnato, Camilo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones En Recursos Naturales, Agroecología y Desarrollo Rural. - Universidad Nacional de Rio Negro. Instituto de Investigaciones En Recursos Naturales, Agroecología y Desarrollo Rural; ArgentinaFil: Ballari, Sebastián A.. Administración de Parques Nacionales. Parque Nacional "Nahuel Huapi"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Guadagnin, Demetrio L.. Universidade Federal do Rio Grande do Sul; BrasilFil: Kindel, Andreas. Universidade Federal do Rio Grande do Sul; BrasilFil: Etges, Matheus. Universidade Federal do Rio Grande do Sul; BrasilFil: Merino, Mariano Lisandro. Universidad Nacional del Noroeste de la Provincia de Buenos Aires; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Marcos, Andrea. Ministerio de Agricultura, Ganadería, Pesca y Alimento. Servicio Nacional de Sanidad y Calidad Agroalimentaria; ArgentinaFil: Skewes, Oscar. Universidad de Concepción; ChileFil: Schettino, Daniella. Instituto de Defesa Agropecuária de Mato Grosso; BrasilFil: Perez, Andres Maximiliano. University of Minnesota; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Condorí, Walter Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Tammone Santos, Agostina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Carpinetti, Bruno Nicolás. Universidad Nacional Arturo Jauretche. Instituto Ciencias Sociales y Administracion; ArgentinaFil: Zalba, Sergio Martín. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Grupo de Estudios en Conservación y Manejo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Shaping immune responses through the activation of dendritic cells–P2 receptors

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    Dendritic cells (DCs) activate and shape the adaptive immune response by capturing antigens, migrating to peripheral lymphoid organs where naïve T cells reside, expressing high levels of MHC and costimulatory molecules and secreting cytokines and chemokines. DCs are endowed with a high degree of functional plasticity and their functions are tightly regulated. Besides initiating adaptive immune responses, DCs play a key role in maintaining peripheral tolerance toward self-antigens. On the basis of the information gathered from the tissue where they reside, DCs adjust their functional activity to ensure that protective immunity is favoured while unwanted or exaggerated immune responses are prevented. A wide variety of signals from neighbouring cells affecting DC functional activity have been described. Here we will discuss the complex role of extracellular nucleotides in the regulation of DC function and the role of P2 receptors as possible tools to manipulate immune responses

    Avian influenza virus isolated in wild waterfowl in Argentina: Evidence of a potentially unique phylogenetic lineage in South America

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    Avian influenza (AI) viruses have been sporadically isolated in South America. The most recent reports are from an outbreak in commercial poultry in Chile in 2002 and its putative ancestor from a wild bird in Bolivia in 2001. Extensive surveillance in wild birds was carried out in Argentina during 2006-2007. Using RRT-PCR, 12 AI positive detections were made from cloacal swabs. One of those positive samples yielded an AI virus isolated from a wild kelp gull (Larus dominicanus) captured in the South Atlantic coastline of Argentina. Further characterization by nucleotide sequencing reveals that it belongs to the H13N9 subtype. Phylogenetic analysis of the 8 viral genes suggests that the 6 internal genes are related to the isolates from Chile and Bolivia. The analysis also indicates that a cluster of phylogenetically related AI viruses from South America may have evolved independently, with minimal gene exchange, from influenza viruses in other latitudes. The data produced from our investigations are valuable contributions to the study of AI viruses in South America.Centro de Estudios Parasitológicos y de Vectore

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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