245 research outputs found

    Mortality in paediatric burns victims: A retrospective review from 2009 to 2012 in a single centre

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    Background. Childhood mortality is high in low- and middle-income countries. Burns are one of the five leading causes of childhood injury mortality in South Africa (SA). While there is an abundance of literature on burns in the developed world, there are far fewer publications dealing with childhood mortality related to burns in Africa and SA.Objective. To describe the mortality of children admitted to a dedicated paediatric burns unit, and investigate factors contributing to reducing mortality.Methods. A retrospective review was performed of patients admitted to the Johnson & Johnson Paediatric Burns Unit, Chris Hani Baragwanath Academic Hospital, Johannesburg, SA, between May 2009 and April 2012.Results. During the study period, 1 372 patients aged ≤10 years were admitted to the unit. There were 1 089 admissions to the general ward and 283 admissions to the paediatric burns intensive care unit (PBICU). The overall mortality rate was 7.9% and the rate for children admitted to the PBICU 29.3%; 90.8% of deaths occurred in children aged ≤5 years. Of children admitted with an inhalational injury, 89.5% died. No child with a burn injury >60% of total body surface area (TBSA) survived.Conclusions. Our overall mortality rate was 7.9%, and the rate declined significantly over the 3-year study period from 11.7% to 5.1%. Age ≤5 years, the presence of inhalational injury, burn injury >30% of TBSA and admission to the PBICU were significant risk factors for mortality

    Organo-functionalized metal–oxide clusters: synthesis and characterization of the reduced cationic species [NaV IV 6 O 6 {(OCH 2 CH 2 ) 2 NH} 6 ] +

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    A new heteropolyoxovanadium compound, [NaV6O6{(OCH2CH2)2NH}6]·(OH)0.5Cl0.5·3(H2O), was synthesized and characterized by single-crystal X-ray diffraction analysis, cyclic voltammetry, FTIR and UV-vis spectroscopy, and TGA. [NaV6O6{(OCH2CH2)2NH}6]·(OH)0.5Cl0.5·3(H2O) contains the diethanolamine functionalized oxovanadium cationic cluster, [NaV(IV)6O6{(OCH2CH2)2NH}6](+). The cluster cation is composed of a fully reduced cyclic {NaV6N6O18} framework which adopts an Anderson-like structure and is comprised of a ring of six edge-sharing {VO5N} octahedra linked to a central {NaO6} unit. Two (OCH2CH2-) arms of each of the six diethanolamine ligands are incorporated into the oxometalate core. FTIR spectra are consistent with the presence of expected V=Ot stretching modes and functionalization with diethanolamine. Electrochemical and UV-vis absorption properties are consistent with two distinct MLCT processes: the characteristic V=Ot dπ-pπ interaction, and a second process occurring through the hydrogen-terminated nitrogen atoms (V-N-H) of the octahedra forming the cyclic {NaV6N6O18} core

    Differential Expression of Cadherin-2 and Cadherin-4 in the Developing and Adult Zebrafish Visual System

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    Cadherins are homophilic cell adhesion molecules that control development of a variety of tissues and maintenance of adult structures. Although cadherins have been implicated in the development of the brain, including the visual system, in several vertebrate species, little is known of their role in zebrafish. In this study, we examined distribution of cadherin-2 (Cdh2, N-cadherin) in the visual system of developing and adult zebrafish using both immunocytochemical and in situ hybridization methods, and we compared Cdh2 distribution to that of the previously reported and closely related cadherin-4 (Cdh4, R-cadherin). As in other vertebrates, in zebrafish embryos Cdh2 was widely expressed in the early nervous system, but its expression became more restricted as development proceeded. Cdh4 was not detectable until later in development, at about the time when the first ganglion cells are generated. Cdh2 and Cdh4 were expressed in distinct regions of developing visual structures, including the lens. We hypothesize that the differential expression of these two cadherins in developing zebrafish visual structures reflects functionally different roles in the development of the vertebrate visual system

    Constitutive Glycolytic Metabolism Supports CD8+ T Cell Effector Memory Differentiation during Viral Infection

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    Extensive metabolic changes accompany T cell activation, including a switch to glycolytic energy production and increased biosynthesis. Recent studies suggest that subsequent return to reliance on oxidative phosphorylation and increasing spare respiratory capacity are essential for the differentiation of memory CD8+ T cells. In contrast, we found that constitutive glycolytic metabolism and suppression of oxidative phosphorylation in CD8+ T cells, achieved by conditional deletion of hypoxia-inducible factor regulator Vhl, accelerated CD8+ memory cell differentiation during viral infection. Despite sustained glycolysis, CD8+ memory cells emerged that upregulated key memory-associated cytokine receptors and transcription factors and showed a heightened response to secondary challenge. In addition, increased glycolysis not only permitted memory formation, but it also favored the formation of long-lived effector-memory CD8+ T cells. These data redefine the role of cellular metabolism in memory cell differentiation, showing that reliance on glycolytic metabolism does not hinder formation of a protective memory population

    Identification of pre-leukaemic haematopoietic stem cells in acute leukaemia.

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    In acute myeloid leukaemia (AML), the cell of origin, nature and biological consequences of initiating lesions, and order of subsequent mutations remain poorly understood, as AML is typically diagnosed without observation of a pre-leukaemic phase. Here, highly purified haematopoietic stem cells (HSCs), progenitor and mature cell fractions from the blood of AML patients were found to contain recurrent DNMT3A mutations (DNMT3A(mut)) at high allele frequency, but without coincident NPM1 mutations (NPM1c) present in AML blasts. DNMT3A(mut)-bearing HSCs showed a multilineage repopulation advantage over non-mutated HSCs in xenografts, establishing their identity as pre-leukaemic HSCs. Pre-leukaemic HSCs were found in remission samples, indicating that they survive chemotherapy. Therefore DNMT3A(mut) arises early in AML evolution, probably in HSCs, leading to a clonally expanded pool of pre-leukaemic HSCs from which AML evolves. Our findings provide a paradigm for the detection and treatment of pre-leukaemic clones before the acquisition of additional genetic lesions engenders greater therapeutic resistance

    A Critical Role of a Cellular Membrane Traffic Protein in Poliovirus RNA Replication

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    Replication of many RNA viruses is accompanied by extensive remodeling of intracellular membranes. In poliovirus-infected cells, ER and Golgi stacks disappear, while new clusters of vesicle-like structures form sites for viral RNA synthesis. Virus replication is inhibited by brefeldin A (BFA), implicating some components(s) of the cellular secretory pathway in virus growth. Formation of characteristic vesicles induced by expression of viral proteins was not inhibited by BFA, but they were functionally deficient. GBF1, a guanine nucleotide exchange factor for the small cellular GTPases, Arf, is responsible for the sensitivity of virus infection to BFA, and is required for virus replication. Knockdown of GBF1 expression inhibited virus replication, which was rescued by catalytically active protein with an intact N-terminal sequence. We identified a mutation in GBF1 that allows growth of poliovirus in the presence of BFA. Interaction between GBF1 and viral protein 3A determined the outcome of infection in the presence of BFA

    Functional Analysis of a Breast Cancer-Associated Mutation in the Intracellular Domain of the Metalloprotease ADAM12

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    A recently identified breast cancer-associated mutation in the metalloprotease ADAM12 alters a potential dileucine trafficking signal, which could affect protein processing and cellular localization. ADAM12 belongs to the group of A Disintegrin And Metalloproteases (ADAMs), which are typically membrane-associated proteins involved in ectodomain shedding, cell-adhesion, and signaling. ADAM12 as well as several members of the ADAM family are over-expressed in various cancers, correlating with disease stage. Three breast cancer-associated somatic mutations were previously identified in ADAM12, and two of these, one in the metalloprotease domain and another in the disintegrin domain, were investigated and found to result in protein misfolding, retention in the secretory pathway, and failure of zymogen maturation. The third mutation, p.L792F in the ADAM12 cytoplasmic tail, was not investigated, but is potentially significant given its location within a di-leucine motif, which is recognized as a potential cellular trafficking signal. The present study was motivated both by the potential relevance of this documented mutation to cancer, as well as for determining the role of the di-leucine motif in ADAM12 trafficking. Expression of ADAM12 p.L792F in mammalian cells demonstrated quantitatively similar expression levels and zymogen maturation as wild-type (WT) ADAM12, as well as comparable cellular localizations. A cell surface biotinylation assay demonstrated that cell surface levels of ADAM12 WT and ADAM12 p.L792F were similar and that internalization of the mutant occurred at the same rate and extent as for ADAM12 WT. Moreover, functional analysis revealed no differences in cell proliferation or ectodomain shedding of epidermal growth factor (EGF), a known ADAM12 substrate between WT and mutant ADAM12. These data suggest that the ADAM12 p.L792F mutation is unlikely to be a driver (cancer causing)-mutation in breast cancer

    COPI Is Required for Enterovirus 71 Replication

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    Enterovirus 71 (EV71), a member of the Picornaviridae family, is found in Asian countries where it causes a wide range of human diseases. No effective therapy is available for the treatment of these infections. Picornaviruses undergo RNA replication in association with membranes of infected cells. COPI and COPII have been shown to be involved in the formation of picornavirus-induced vesicles. Replication of several picornaviruses, including poliovirus and Echovirus 11 (EV11), is dependent on COPI or COPII. Here, we report that COPI, but not COPII, is required for EV71 replication. Replication of EV71 was inhibited by brefeldin A and golgicide A, inhibitors of COPI activity. Furthermore, we found EV71 2C protein interacted with COPI subunits by co-immunoprecipitation and GST pull-down assay, indicating that COPI coatomer might be directed to the viral replication complex through viral 2C protein. Additionally, because the pathway is conserved among different species of enteroviruses, it may represent a novel target for antiviral therapies
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