329 research outputs found

    Hunting the Collectors: Pacific Collections in Australian Museums, Galleries and Archives

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    This volume investigates Pacific collections held in Australian - museums, art galleries and archives, and the diverse group of 19th and 20th century collectors responsible for their acquisition. The nineteen essays reveal varied personal and institutional motivations that eventually led to the conservation, preservation and exhibition in Australia of a remarkable archive of Pacific Island material objects, art and crafts, photographs and documents. Hunting the Collectors benchmarks the importance of Pacific Collections in Australia and is a timely contribution to the worldwide renaissance of interest in Oceanic arts and cultures. The essays suggest that the custodial role is not fixed and immutable but fluctuates with the perceived importance of the collection, which in turn fluctuates with the level of national interest in the Pacific neighbourhood. This cyclical rise and fall of Australian interest in the Pacific Islands means many of the valuable early collections in state and later national repositories and institutions have been rarely exhibited or published. But, as the authors note, enthusiastic museum anthropologists, curators, collection managers and university-based scholars across Australia, and worldwide, have persisted with research on material collected in the Pacific

    Selective translational repression of HIV-1 RNA by Sam68DeltaC occurs by altering PABP1 binding to unspliced viral RNA

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    HIV-1 structural proteins are translated from incompletely spliced 9 kb and 4 kb mRNAs, which are transported to the cytoplasm by Crm1. It has been assumed that once in the cytoplasm, translation of incompletely spliced HIV-1 mRNAs occurs in the same manner as host mRNAs. Previous analyses have demonstrated that Sam68 and a mutant thereof, Sam68ΔC, have dramatic effects on HIV gene expression, strongly enhancing and inhibiting viral structural protein synthesis, respectively. While investigating the inhibition of incompletely spliced HIV-1 mRNAs by Sam68ΔC, we determined that the effect was independent of the perinuclear bundling of the viral RNA. Inhibition was dependent upon the nuclear export pathway used, as translation of viral RNA exported via the Tap/CTE export pathway was not blocked by Sam68ΔC. We demonstrate that inhibition of HIV expression by Sam68ΔC is correlated with a loss of PABP1 binding with no attendant change in polyadenosine tail length of the affected RNAs. The capacity of Sam68ΔC to selectively inhibit translation of HIV-1 RNAs exported by Crm1 suggests that it is able to recognize unique characteristics of these viral RNPs, a property that could lead to new therapeutic approaches to controlling HIV-1 replication

    hnRNP E1 and E2 have distinct roles in modulating HIV-1 gene expression

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    Pre-mRNA processing, including 5' end capping, splicing, and 3' end cleavage/polyadenylation, are events coordinated by transcription that can influence the subsequent export and translation of mRNAs. Coordination of RNA processing is crucial in retroviruses such as HIV-1, where inefficient splicing and the export of intron-containing RNAs are required for expression of the full complement of viral proteins. RNA processing can be affected by both viral and cellular proteins, and in this study we demonstrate that a member of the hnRNP E family of proteins can modulate HIV-1 RNA metabolism and expression. We show that hnRNP E1/E2 are able to interact with the ESS3a element of the bipartite ESS in tat/rev exon 3 of HIV-1 and that modulation of hnRNP E1 expression alters HIV-1 structural protein synthesis. Overexpression of hnRNP E1 leads to a reduction in Rev, achieved in part through a decrease in rev mRNA levels. However, the reduction in Rev levels cannot fully account for the effect of hnRNP E1, suggesting that hmRNP E1 might also act to suppress viral RNA translation. Deletion mutagenesis determined that the C-terminal end of hnRNP E1 was required for the reduction in Rev expression and that replacing this portion of hnRNP E1 with that of hnRNP E2, despite the high degree of conservation, could not rescue the loss of function

    Characterization of novel inhibitors of HIV-1 replication that function via alteration of viral RNA processing and rev function

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    Expression of the complete HIV-1 genome depends on the appropriate processing of viral RNA. Altering the balance of viral RNA processing impairs replication of the virus. In this report, we characterize two small molecule modulators of HIV-1 RNA processing, 8-azaguanine and 2-(2-(5-nitro-2-thienyl)vinyl)quinoline (5350150), which function by distinct mechanisms to suppress viral gene expression. Although only 8-Azaguanine dramatically decreased accumulation of HIV-1 unspliced and singly spliced RNAs and altered splice site usage, both compounds blocked Gag and Env expression without affecting production of Tat (p16) and Rev regulatory proteins. Subsequent analyses suggest that these compounds affect Rev-mediated RNA transport by different mechanisms. Both compounds induced cytoplasmic accumulation of Rev, suggesting that they function, in part, by impairing Rev function. This conclusion is supported by the determination that both drugs block the nuclear export of genomic HIV-1 RNA to the cytoplasm. Testing confirmed that these compounds suppress HIV-1 expression in T cells at doses below those previously used in humans for tumour chemotherapy. Together, our observations demonstrate that small molecules can be used to inhibit HIV-1 replication by altering another avenue of viral RNA processing, offering the potential for the development of novel therapeutics for controlling this disease

    Differential effect of CLK SR Kinases on HIV-1 gene expression: potential novel targets for therapy

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    <p>Abstract</p> <p>Background</p> <p>RNA processing plays a critical role in the replication of HIV-1, regulated in part through the action of host SR proteins. To explore the impact of modulating SR protein activity on virus replication, the effect of increasing or inhibiting the activity of the Cdc2-like kinase (CLK) family of SR protein kinases on HIV-1 expression and RNA processing was examined.</p> <p>Results</p> <p>Despite their high homology, increasing individual CLK expression had distinct effects on HIV-1, CLK1 enhancing Gag production while CLK2 inhibited the virus. Parallel studies on the anti-HIV-1 activity of CLK inhibitors revealed a similar discrepant effect on HIV-1 expression. TG003, an inhibitor of CLK1, 2 and 4, had no effect on viral Gag synthesis while chlorhexidine, a CLK2, 3 and 4 inhibitor, blocked virus production. Chlorhexidine treatment altered viral RNA processing, decreasing levels of unspliced and single spliced viral RNAs, and reduced Rev accumulation. Subsequent experiments in the context of HIV-1 replication in PBMCs confirmed the capacity of chlorhexidine to suppress virus replication.</p> <p>Conclusions</p> <p>Together, these findings establish that HIV-1 RNA processing can be targeted to suppress virus replication as demonstrated by manipulating individual CLK function and identified chlorhexidine as a lead compound in the development of novel anti-viral therapies.</p

    The Natural Product Lepidiline A as an N-Heterocyclic Carbene Ligand Precursor in Complexes of the Type [Ir(cod)(NHC)PPh3)]X: Synthesis, Characterisation, and Application in Hydrogen Isotope Exchange Catalysis

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    A range of iridium(I) complexes of the type [Ir(cod)(NHC)PPh3)]X are reported, where the N-heterocyclic carbene (NHC) is derived from the naturally-occurring imidaozlium salt, Lepidiline A (1,3-dibenzyl-4,5-dimethylimidazolium chloride). A range of complexes were prepared, with a number of NHC ligands and counter-ions, and various steric and electronic parameters of these complexes were evaluated. The activity of the [Ir(cod)(NHC)PPh3)]X complexes in hydrogen isotope exchange reactions was then studied, and compared to established iridium(I) complexes

    Inhibition of HIV-1 gene expression by Sam68ΔC: multiple targets but a common mechanism?

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    Two recent publications have explored the mechanisms by which a mutant of the host protein Sam68 blocks HIV-1 structural protein synthesis and expands its activity to encompass Nef. Although the two studies propose different mechanisms for the responses observed, it is possible that a common activity is responsible. Understanding how this Sam68 mutant discriminates among the multiple viral mRNAs promises to reveal unique properties of HIV-1 RNA metabolism

    Drowsy and dangerous? Fatigue in paramedics: an overview

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    BackgroundFatigue is a complex phenomenon that has effects on physical characteristics, cognition, behaviours, and physical and mental health. Paramedicine crosses the boundaries of many high-risk industries, namely medicine, transport and aviation. The effects of fatigue on paramedics thus need to be explored and considered in order to begin to identify appropriate interventions and management strategies.AimThe aim of this article was to provide an overview of fatigue in paramedics and its potential effects on various areas of paramedic practice and paramedic health, and to outline potential solutions to assess and manage the risk of fatigue in paramedics as suggested by the literature.MethodsWe conducted unstructured, non-systematic searches of the literature in order to inform an overview of the literature. An overview is a summary of the literature that attempts to survey the literature and describe its characteristics. We thematically structured the review under the following headings: defining occupational activity and health status; clinical performance and patient safety; shift length and time at work; effects on paramedic health; effects on driving abilities; fatigue risk management; and, fatigue proofing.DiscussionFatigue should be considered in the context of overall paramedic health status and paramedic occupational activity. The nature of paramedic shift work, and the associated occupational activity place paramedics at increased risk from fatigue. Shift work may also contribute to sleep disorders among paramedics. Fatigue is associated with increased errors and adverse events, increased chronic disease and injury rates, depression and anxiety, and impaired driving ability.ConclusionThe issue of fatigue in paramedicine is complex and has serious consequences for patients and paramedics. Paramedic services and paramedics need to work collaboratively to identify and action appropriate measures to reduce the effects of fatigue on the wellbeing of the workforce and mitigate its effects on clinical performance and safety

    Quaking is a Key Regulator of Endothelial Cell Differentiation, Neovascularization and Angiogenesis

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    Abstract The capability to derive endothelial cell (ECs) from induced pluripotent stem cells (iPSCs) holds huge therapeutic potential for cardiovascular disease. This study elucidates the precise role of the RNA-binding protein Quaking isoform 5 (QKI-5) during EC differentiation from both mouse and human iPSCs (hiPSCs) and dissects how RNA-binding proteins can improve differentiation efficiency toward cell therapy for important vascular diseases. iPSCs represent an attractive cellular approach for regenerative medicine today as they can be used to generate patient-specific therapeutic cells toward autologous cell therapy. In this study, using the model of iPSCs differentiation toward ECs, the QKI-5 was found to be an important regulator of STAT3 stabilization and vascular endothelial growth factor receptor 2 (VEGFR2) activation during the EC differentiation process. QKI-5 was induced during EC differentiation, resulting in stabilization of STAT3 expression and modulation of VEGFR2 transcriptional activation as well as VEGF secretion through direct binding to the 3′ UTR of STAT3. Importantly, mouse iPS-ECs overexpressing QKI-5 significantly improved angiogenesis and neovascularization and blood flow recovery in experimental hind limb ischemia. Notably, hiPSCs overexpressing QKI-5, induced angiogenesis on Matrigel plug assays in vivo only 7 days after subcutaneous injection in SCID mice. These results highlight a clear functional benefit of QKI-5 in neovascularization, blood flow recovery, and angiogenesis. Thus, they provide support to the growing consensus that elucidation of the molecular mechanisms underlying EC differentiation will ultimately advance stem cell regenerative therapy and eventually make the treatment of cardiovascular disease a reality. The RNA binding protein QKI-5 is induced during EC differentiation from iPSCs. RNA binding protein QKI-5 was induced during EC differentiation in parallel with the EC marker CD144. Immunofluorescence staining showing that QKI-5 is localized in the nucleus and stained in parallel with CD144 in differentiated ECs (scale bar = 50 µm).</jats:p
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