283 research outputs found

    Fatal anaphylactoid response to protamine after percutaneous transluminal coronary angioplasty

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    A generalized skin erythema and severe hypotension developed following administration of protamine for the reversal of heparin anticoagulation after an unsuccessful attempt at percutaneous transluminal angioplasty in a patient who had never been exposed to protamines before. Evidence of classical pathway complement activation was present indicating that this reaction could have been triggered by a non-immunological mechanism. The patient could not adequately be resuscitated because of the presence of severe coronary artery diseas

    Effects of the Bacterial Extract OM-85 on Phagocyte Functions and the Stress Response

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    The effects of the bacterial extract OM-85 on the respiratory burst, intracellular calcium and the stress response have been investigated in human peripheral blood monocytes from normal donors. Activation of the respiratory burst during bacterial phagocytosis has been previously associated with heat shock/stress proteins synthesis. Whereas OM-85 stimulated superoxide production and increased Ca2+ mobilization, it fared to induce synthesis of classical HSPs. The lack of stress protein induction was observed even in the presence of iron which potentiates both oxidative injury and stress protein induction during bacterial phagocytosis. However OM-85 induced a 75–78 kDa protein, which is likely to be a glucose regulated protein (GRP78), and enhanced intracellular expression of interleukin-lβ precursor

    The spindle assembly checkpoint is satisfied in the absence of interkinetochore tension during mitosis with unreplicated genomes

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    The accuracy of chromosome segregation is enhanced by the spindle assembly checkpoint (SAC). The SAC is thought to monitor two distinct events: attachment of kinetochores to microtubules and the stretch of the centromere between the sister kinetochores that arises only when the chromosome becomes properly bioriented. We examined human cells undergoing mitosis with unreplicated genomes (MUG). Kinetochores in these cells are not paired, which implies that the centromere cannot be stretched; however, cells progress through mitosis. A SAC is present during MUG as cells arrest in response to nocodazole, taxol, or monastrol treatments. Mad2 is recruited to unattached MUG kinetochores and released upon their attachment. In contrast, BubR1 remains on attached kinetochores and exhibits a level of phosphorylation consistent with the inability of MUG spindles to establish normal levels of centromere tension. Thus, kinetochore attachment to microtubules is sufficient to satisfy the SAC even in the absence of interkinetochore tension

    Economic space: On the analysis and interpretation of pottery production and distribution

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    Ceramics are particularly well suited for investigating general patterns of the distribution of premodern products. Archaeometric methods, used to determine raw materials and production techniques, permit the identification of places of production. The work of the research group presented here pursues two objectives: (i) to investigate the usefulness of portable X-ray fluorescence equipment for the analysis of ceramics and (ii) to identify, interpret and study distribution areas of ceramic products in comparative prospective. The paper discusses key economic concepts, sets out the archaeometric methodology and presents initial results in the context of two examples

    High temperature susceptibility in electron doped Ca1-xYxMnO3: Double Exchange vs Superexchange

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    We present a study of the magnetic properties of the electron doped manganites Ca1-xYxMnO3 (for 0<=x<=0.25) in the paramagnetic regime. For the less doped samples (x<=0.1) the magnetic susceptibility, c(T), follows a Curie-Weiss (CW) law only for T > 450 K and, below this temperature, c^-1(T) shows a ferrimagnetic-like curvature. We approached the discussion of these results in terms of a simple mean-field model where double exchange, approximated by a ferromagnetic Heisenberg-like interaction between Mn3+ and Mn4+ ions, competes with classical superexchange. For higher levels of doping (x>=0.15), the CW behaviour is observed down to the magnetic ordering temperature (Tmo) and a better description of c(T) was obtained by assuming full delocalization of the eg electrons. In order to explore the degree of delocalization as a function of T and x, we analyzed the problem through Montecarlo simulations. Within this picture we found that at high T the electrons doped are completely delocalized but, when Tmo is approached, they form magnetic polarons of large spin that cause the observed curvature in c^-1(T) for x<=0.1.Comment: 15 pages, 10 figures, Submitted to J. Physics: Condensed Matter (06/28/02

    The use of raman spectroscopy, X-ray diffraction and electron microscopy in the analysis of pigments from vaquerías ceramics

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    Se presentan resultados del estudio arqueométrico de pigmentos rojos y negros provenientes de diseños pintados en cerámicas Vaquerías, estilo polícromo del Período Formativo del Noroeste Argentino. Se combinan las técnicas de espectroscopia Raman, difracción de rayos X (DRX) y microscopia electrónica de barrido con espectroscopia de energía dispersiva (SEM-EDS) para analizar la composición de los pigmentos en fragmentos de piezas cerámicas de los sitios Cardonal y Bordo Marcial (Catamarca, Argentina). Los pigmentos rojos están compuestos esencialmente de hematita; en los pigmentos negros se determinó alto contenido de manganeso y se confirmó la presencia de jacobsita y bixbyita.This paper presents the results of using archaeometric techniques to analyze red and black pigments from designs painted onto Vaquerías ceramics (a polychrome style of the Argentine Northwest Formative period). Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) were all employed in the compositional analysis of pigments on ceramic pieces from Cardonal and Bordo Marcial (Catamarca, Argentina) that were inhabited during the first two centuries of the Christian era. The red pigments have proven to be primarily hematite, while black pigments showed high contents of manganese and the presence of jacobsite and bixbyite.Facultad de Ciencias Naturales y Muse

    Identification of a Cell-of-Origin for Fibroblasts Comprising the Fibrotic Reticulum in Idiopathic Pulmonary Fibrosis

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    Idiopathic pulmonary fibrosis (IPF) is a progressive disease of the middle aged and elderly with a prevalence of one million persons worldwide. The fibrosis spreads from affected alveoli into contiguous alveoli, creating a reticular network that leads to death by asphyxiation. Lung fibroblasts from patients with IPF have phenotypic hallmarks, distinguishing them from their normal counterparts: pathologically activated Akt signaling axis, increased collagen and α-smooth muscle actin expression, distinct gene expression profile, and ability to form fibrotic lesions in model organisms. Despite the centrality of these fibroblasts in disease pathogenesis, their origin remains uncertain. Here, we report the identification of cells in the lungs of patients with IPF with the properties of mesenchymal progenitors. In contrast to progenitors isolated from nonfibrotic lungs, IPF mesenchymal progenitor cells produce daughter cells manifesting the full spectrum of IPF hallmarks, including the ability to form fibrotic lesions in zebrafish embryos and mouse lungs, and a transcriptional profile reflecting these properties. Morphological analysis of IPF lung tissue revealed that mesenchymal progenitor cells and cells with the characteristics of their progeny comprised the fibrotic reticulum. These data establish that the lungs of patients with IPF contain pathological mesenchymal progenitor cells that are cells of origin for fibrosis-mediating fibroblasts. These fibrogenic mesenchymal progenitors and their progeny represent an unexplored target for novel therapies to interdict fibrosis
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