1,944 research outputs found

    Nonthermal Emission from Star-Forming Galaxies

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    The detections of high-energy gamma-ray emission from the nearby starburst galaxies M82 & NGC253, and other local group galaxies, broaden our knowledge of star-driven nonthermal processes and phenomena in non-AGN star-forming galaxies. We review basic aspects of the related processes and their modeling in starburst galaxies. Since these processes involve both energetic electrons and protons accelerated by SN shocks, their respective radiative yields can be used to explore the SN-particle-radiation connection. Specifically, the relation between SN activity, energetic particles, and their radiative yields, is assessed through respective measures of the particle energy density in several star-forming galaxies. The deduced energy densities range from O(0.1) eV/cm^3 in very quiet environments to O(100) eV/cm^3 in regions with very high star-formation rates.Comment: 17 pages, 5 figures, to be published in Astrophysics and Space Science Proceeding

    Galectins as immunoregulators during infectious processes: from microbial invasion to the resolution of the disease

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    Recent evidence has implicated galectins, a family of evolutionarily conserved carbohydrate-binding proteins, as regulators of immune cell homeostasis and host-pathogen interactions. Galectins operate at different levels of innate and adaptive immune responses, by modulating cell survival and cell activation or by influencing the Th1/Th2 cytokine balance. Furthermore, galectins may contribute to host-pathogen recognition and may serve as receptors for specific interactions of pathogens with their insect vectors. Here we will explore the influence of galectins in immunological processes relevant to microbial infection and will summarize exciting recent work related to the specific interactions between galectins and their glycoconjugate ligands as critical determinants of pathogen recognition. Understanding the role of galectin-sugar interactions during the course of microbial infections might contribute to defining novel targets for disease prevention and immune intervention.Fil: Rabinovich, Gabriel Adrián. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Gruppi, Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentin

    NF-κB activation in inflammatory breast cancer is associated with oestrogen receptor downregulation, secondary to EGFR and/or ErbB2 overexpression and MAPK hyperactivation

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    Activation of NF-κB in inflammatory breast cancer (IBC) is associated with loss of estrogen receptor (ER) expression, indicating a potential crosstalk between NF-κB and ER. In this study, we examined the activation of NF-κB in IBC and non-IBC with respect to ER and EGFR and/or ErbB2 expression and MAPK hyperactivation. A qRT–PCR based ER signature was evaluated in tumours with and without transcriptionally active NF-κB, as well as correlated with the expression of eight NF-κB target genes. Using a combined ER/NF-κB signature, hierarchical clustering was executed. Hyperactivation of MAPK was investigated using a recently described MAPK signature (Creighton et al, 2006), and was linked to tumour phenotype, ER and EGFR and/or ErbB2 overexpression. The expression of most ER-modulated genes was significantly elevated in breast tumours without transcriptionally active NF-κB. In addition, the expression of most ER-modulated genes was significantly anticorrelated with the expression of most NF-κB target genes, indicating an inverse correlation between ER and NF-κB activation. Clustering using the combined ER and NF-κB signature revealed one cluster mainly characterised by low NF-κB target gene expression and a second one with elevated NF-κB target gene expression. The first cluster was mainly characterised by non-IBC specimens and IHC ER+ breast tumours (13 out of 18 and 15 out of 18 respectively), whereas the second cluster was mainly characterised by IBC specimens and IHC ER− breast tumours (12 out of 19 and 15 out of 19 respectively) (Pearson χ2, P<0.0001 and P<0.0001 respectively). Hyperactivation of MAPK was associated with both ER status and tumour phenotype by unsupervised hierarchical clustering using the MAPK signature and was significantly reflected by overexpression of EGFR and/or ErbB2. NF-κB activation is linked to loss of ER expression and activation in IBC and in breast cancer in general. The inverse correlation between NF-κB activation and ER activation is due to EGFR and/or ErbB2 overexpression, resulting in NF-κB activation and ER downregulation

    The FRESHAIR4Life study:Global implementation research on non-communicable disease prevention targeting adolescents' exposure to tobacco and air pollution in disadvantaged populations

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    In the FRESHAIR4Life study, we aim to reduce the non-communicable disease (NCD) burden by implementing preventive interventions targeting adolescents’ exposure to tobacco use and air pollution (AP). This paper presents the methodology of FRESHAIR4Life and initial rapid review results. The rapid review showed variable NCD mortality rates related to tobacco use and AP exposure in the five participating countries. Tobacco is the predominant risk factor for NCD-related deaths in the Kyrgyz Republic, Greece, and Romania, whereas AP exposure causes most NCD-related deaths in Pakistan and Uganda. Adolescents’ risk factor exposure, sources of exposure, and trends also differ significantly. As the next step in FRESHAIR4Life, an in-depth situational analysis will inform the selection, adaptation, and integration of evidence-based interventions into the FRESHAIR4Life prevention package. Subsequently, this package will be implemented, evaluated, and iteratively refined. Throughout the research process, a strong emphasis is on co-creation, capacity building, and comprehensive communication and dissemination

    Successful bone marrow transplantation in a patient with Diamond-Blackfan anemia with co-existing Duchenne muscular dystrophy: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Diamond-Blackfan anemia and Duchenne muscular dystrophy are two rare congenital anomalies. Both anomalies occurring in the same child is extremely rare. Allogeneic hematopoietic stem cell transplantation is a well-established therapy for Diamond-Blackfan anemia. However, in patients with Duchenne muscular dystrophy, stem cell therapy still remains experimental.</p> <p>Case presentation</p> <p>We report the case of a nine-year-old boy of north Indian descent with Diamond-Blackfan anemia and Duchenne muscular dystrophy who underwent successful allogeneic hematopoietic stem cell transplantation. He is transfusion-independent, and his Duchenne muscular dystrophy has shown no clinical deterioration over the past 45 months. His creatine phosphokinase levels have significantly decreased to 300 U/L from 14,000 U/L pre-transplant. The patient is 100% donor chimera in the hematopoietic system, and his muscle tissue has shown 8% to 10.4% cells of donor origin.</p> <p>Conclusion</p> <p>Our patient's Diamond-Blackfan anemia was cured by allogeneic hematopoietic stem cell transplantation. The interesting clinical observation of a possible benefit in Duchenne muscular dystrophy cannot be ruled out. However, further clinical follow-up with serial muscle biopsies and molecular studies are needed to establish this finding.</p

    The FRESHAIR4Life study:Global implementation research on non-communicable disease prevention targeting adolescents' exposure to tobacco and air pollution in disadvantaged populations

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    In the FRESHAIR4Life study, we aim to reduce the non-communicable disease (NCD) burden by implementing preventive interventions targeting adolescents’ exposure to tobacco use and air pollution (AP). This paper presents the methodology of FRESHAIR4Life and initial rapid review results. The rapid review showed variable NCD mortality rates related to tobacco use and AP exposure in the five participating countries. Tobacco is the predominant risk factor for NCD-related deaths in the Kyrgyz Republic, Greece, and Romania, whereas AP exposure causes most NCD-related deaths in Pakistan and Uganda. Adolescents’ risk factor exposure, sources of exposure, and trends also differ significantly. As the next step in FRESHAIR4Life, an in-depth situational analysis will inform the selection, adaptation, and integration of evidence-based interventions into the FRESHAIR4Life prevention package. Subsequently, this package will be implemented, evaluated, and iteratively refined. Throughout the research process, a strong emphasis is on co-creation, capacity building, and comprehensive communication and dissemination

    MSH3 polymorphisms and protein levels affect CAG repeat instability in huntington's disease mice

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    Expansions of trinucleotide CAG/CTG repeats in somatic tissues are thought to contribute to ongoing disease progression through an affected individual's life with Huntington's disease or myotonic dystrophy. Broad ranges of repeat instability arise between individuals with expanded repeats, suggesting the existence of modifiers of repeat instability. Mice with expanded CAG/CTG repeats show variable levels of instability depending upon mouse strain. However, to date the genetic modifiers underlying these differences have not been identified. We show that in liver and striatum the R6/1 Huntington's disease (HD) (CAG)~100 transgene, when present in a congenic C57BL/6J (B6) background, incurred expansion-biased repeat mutations, whereas the repeat was stable in a congenic BALB/cByJ (CBy) background. Reciprocal congenic mice revealed the Msh3 gene as the determinant for the differences in repeat instability. Expansion bias was observed in congenic mice homozygous for the B6 Msh3 gene on a CBy background, while the CAG tract was stabilized in congenics homozygous for the CBy Msh3 gene on a B6 background. The CAG stabilization was as dramatic as genetic deficiency of Msh2. The B6 and CBy Msh3 genes had identical promoters but differed in coding regions and showed strikingly different protein levels. B6 MSH3 variant protein is highly expressed and associated with CAG expansions, while the CBy MSH3 variant protein is expressed at barely detectable levels, associating with CAG stability. The DHFR protein, which is divergently transcribed from a promoter shared by the Msh3 gene, did not show varied levels between mouse strains. Thus, naturally occurring MSH3 protein polymorphisms are modifiers of CAG repeat instability, likely through variable MSH3 protein stability. Since evidence supports that somatic CAG instability is a modifier and predictor of disease, our data are consistent with the hypothesis that variable levels of CAG instability associated with polymorphisms of DNA repair genes may have prognostic implications for various repeat-associated diseases

    PIP5KIβ Selectively Modulates Apical Endocytosis in Polarized Renal Epithelial Cells

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    Localized synthesis of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] at clathrin coated pits (CCPs) is crucial for the recruitment of adaptors and other components of the internalization machinery, as well as for regulating actin dynamics during endocytosis. PtdIns(4,5)P2 is synthesized from phosphatidylinositol 4-phosphate by any of three phosphatidylinositol 5-kinase type I (PIP5KI) isoforms (α, β or γ). PIP5KIβ localizes almost exclusively to the apical surface in polarized mouse cortical collecting duct cells, whereas the other isoforms have a less polarized membrane distribution. We therefore investigated the role of PIP5KI isoforms in endocytosis at the apical and basolateral domains. Endocytosis at the apical surface is known to occur more slowly than at the basolateral surface. Apical endocytosis was selectively stimulated by overexpression of PIP5KIβ whereas the other isoforms had no effect on either apical or basolateral internalization. We found no difference in the affinity for PtdIns(4,5)P2-containing liposomes of the PtdIns(4,5)P2 binding domains of epsin and Dab2, consistent with a generic effect of elevated PtdIns(4,5)P2 on apical endocytosis. Additionally, using apical total internal reflection fluorescence imaging and electron microscopy we found that cells overexpressing PIP5KIβ have fewer apical CCPs but more internalized coated structures than control cells, consistent with enhanced maturation of apical CCPs. Together, our results suggest that synthesis of PtdIns(4,5)P2 mediated by PIP5KIβ is rate limiting for apical but not basolateral endocytosis in polarized kidney cells. PtdIns(4,5)P2 may be required to overcome specific structural constraints that limit the efficiency of apical endocytosis. © 2013 Szalinski et al
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