288 research outputs found

    Questioning conventional enterprise wisdom

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    Government (and academic) interest in enterprise (including entrepreneurs and small businesses) largely emerged in the early 1980s when unemployment was rising and research suggested that small businesses were the main source of new jobs. Therefore there was a desire to know more about enterprise in order to encourage it but, like any emerging subject, its early understanding was based more on myth and supposition than ‘scientifically’ established facts. Subsequently much of that understanding appears to have become the conventional wisdom about enterprise which is largely taken on trust and not questioned. But, to those who examine it, problems are apparent, not least because policy apparently based on it does not work. Studies of epistemology suggest that this is to be expected and the review of the links between enterprise research and policy indicates that a disconnect is to be expected there also. Therefore the purpose of this thesis is to identify the body of ‘knowledge’ that has formed the basis for received enterprise wisdom and examine the hypothesis that: Policy has been informed, guided and/or justified by this conventional wisdom – but the failure of policy raises questions about its veracity. This conventional wisdom has not just influenced policy but is also likely to be the foundation for other current thinking about enterprise. However the ‘conventional wisdom is itself based on, or consistent with, a set of assumptions, often not consciously made and therefore not recorded, but at least some of which may be questionable. The research identifies a set of assumptions and shows that they could have been and were adopted and do seem to provide a basis for the conventional wisdom but, nevertheless, are wrong. It therefore concludes that if enterprise understanding is to improve, and enterprise budgets not wasted, this paradigm needs to be changed

    Differential efficacy of vaccinia virus envelope proteins administered by DNA immunisation in protection of BALB/c mice from a lethal intranasal poxvirus challenge

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    DNA vaccines might offer an alternative to the live smallpox vaccine in providing protective efficacy in an orthopoxvirus (OPV) lethal respiratory challenge model. BALB/c mice were immunised with DNA vaccines coding for 10 different single vaccinia virus (VACV) membrane proteins. After an intranasal challenge with the VACV IHD strain, three gene candidates B5R, A33R and A27L produced > or =66% survival. The B5R DNA vaccine consistently produced 100% protection and exhibited greatest efficacy after three 50 microg intramuscular doses in this model. Sero-conversion to these vaccines was often inconsistent, implying that antibody itself was not a correlate of protection. The B5R DNA vaccine induced a strong and consistent gamma interferon (IFNgamma) response in BALB/c mice given a single DNA vaccine dose. Strong IFNgamma responses were also measured in pTB5R immunised C57BL6 mice deficient for MHC class I molecules, suggesting that the memory response was mediated by a CD4+ T cell population

    HCV and the hepatic lipid pathway as a potential treatment target

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    Atherosclerosis has been described as a liver disease of the heart. The liver is the central regulatory organ of lipid pathways but since dyslipidaemias are major contributors to cardiovascular disease and type 2 diabetes rather than liver disease, research in this area has not been a major focus for hepatologists. Virus-host interaction is a continuous co-evolutionary process involving the host immune system and viral escape mechanisms. One of the strategies HCV has adopted to escape immune clearance and establish persistent infection is to make use of hepatic lipid pathways. This review aims to: update the hepatologist on lipid metabolism; review the evidence that HCV exploits hepatic lipid pathways to its advantage; discuss approaches to targeting host lipid pathways as adjunctive therapy

    Heterologous prime-boost-boost immunisation of Chinese cynomolgus macaques using DNA and recombinant poxvirus vectors expressing HIV-1 virus-like particles

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    Background: There is renewed interest in the development of poxvirus vector-based HIV vaccines due to the protective effect observed with repeated recombinant canarypox priming with gp120 boosting in the recent Thai placebo-controlled trial. This study sought to investigate whether a heterologous prime-boost-boost vaccine regimen in Chinese cynomolgus macaques with a DNA vaccine and recombinant poxviral vectors expressing HIV virus-like particles bearing envelopes derived from the most prevalent clades circulating in sub-Saharan Africa, focused the antibody response to shared neutralising epitopes. Methods: Three Chinese cynomolgus macaques were immunised via intramuscular injections using a regimen composed of a prime with two DNA vaccines expressing clade A Env/clade B Gag followed by boosting with recombinant fowlpox virus expressing HIV-1 clade D Gag, Env and cholera toxin B subunit followed by the final boost with recombinant modified vaccinia virus Ankara expressing HIV-1 clade C Env, Gag and human complement protein C3d. We measured the macaque serum antibody responses by ELISA, enumerated T cell responses by IFN-gamma ELISpot and assessed seroneutralisation of HIV-1 using the TZM-bl beta-galactosidase assay with primary isolates of HIV-1. Results: This study shows that large and complex synthetic DNA sequences can be successfully cloned in a single step into two poxvirus vectors: MVA and FPV and the recombinant poxviruses could be grown to high titres. The vaccine candidates showed appropriate expression of recombinant proteins with the formation of authentic HIV virus-like particles seen on transmission electron microscopy. In addition the b12 epitope was shown to be held in common by the vaccine candidates using confocal immunofluorescent microscopy. The vaccine candidates were safely administered to Chinese cynomolgus macaques which elicited modest T cell responses at the end of the study but only one out of the three macaques elicited an HIV-specific antibody response. However, the antibodies did not neutralise primary isolates of HIV-1 or the V3-sensitive isolate SF162 using the TZM-bl b-galactosidase assay. Conclusions: MVA and FP9 are ideal replication-deficient viral vectors for HIV-1 vaccines due to their excellent safety profile for use in humans. This study shows this novel prime-boost-boost regimen was poorly immunogenic in Chinese cynomolgus macaques

    Revisiting the Elusive Hepatitis C Vaccine

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    The impactful discovery and subsequent characterisation of hepatitis C virus (HCV), an RNA virus of the flavivirus family, led to the awarding of the 2020 Nobel Prize in Physiology or Medicine to Harvey J. Alter, Michael Houghton and Charles M. Rice [...

    Optimisation and application of a novel method to identify bacteriophage in maternal milk and infant stool identifies host-phage communities within preterm infant gut

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    Human milk oligosaccharides, proteins such as lactoferrin, and bacteria represent just some of the bioactive components of mothers’ breast milk (BM). Bacteriophages (viruses that infect bacteria) are an often-overlooked component of BM that can cause major changes in microbial composition and metabolism. BM bacteriophage composition has been explored in term and healthy infants, suggesting vertical transmission of bacteriophages occurs between mothers and their infants. Several important differences between term and very preterm infants (< 30 weeks gestational age) may limit this phenomenon in the latter. To better understand the link between BM bacteriophages and gut microbiomes of very preterm infants in health and disease, standardised protocols are required for isolation and characterisation from BM. In this study we use isolated nucleic acid content, bacteriophage richness and Shannon diversity to validate several parameters applicable during bacteriophage isolation from precious BM samples. Parameters validated include sample volume required; centrifugal sedimentation of microbes; hydrolysis of milk samples with digestive enzymes; induction of temperate bacteriophages and concentration / purification of isolated bacteriophage particles in donor milk (DM). Our optimised method enables characterisation of bacteriophages from as little as 0.1 mL BM. We identify viral families that were exclusively identified with inclusion of induction of temperate bacteriophages (Inoviridae) and hydrolysis of milk lipid processes (Iridoviridae and Baculoviridae). Once applied to a small clinical cohort we demonstrate vertical transmission of bacteriophages from mothers BM to the gut of very preterm infants at the species level. This optimised method will enable future research characterising the bacteriophage composition of BM in very preterm infants to determine their clinical relevance in the development of a healthy preterm infant gut microbiome
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