1
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Craigie CR, Johnson PL, Shorten PR, Charteris A, Maclennan G, Tate ML, Agnew MP, Taukiri KR, Stuart AD, Reis MM. Application of Hyperspectral imaging to predict the pH, intramuscular fatty acid content and composition of lamb M. longissimus lumborum at 24h post mortem. Meat Sci 2017; 132:19-28. [PMID: 28551294 DOI: 10.1016/j.meatsci.2017.04.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/12/2017] [Accepted: 04/15/2017] [Indexed: 10/19/2022]
Abstract
Cost-effective, rapid and objective measurement of lamb quality on a routine basis is an important step for lamb value chains wishing to manage lamb product quality. Hyperspectral imaging (HSI) technology has shown promise as a solution for objective non-invasive prediction of meat quality. The performance of HSI applied 24h post mortem to lamb M. longissimus lumborum (LL) within a processing plant environment was assessed over two sampling years to evaluate its suitability for an objective lamb meat quality assurance tool. Calibration and validation steps were undertaken to evaluate HSI prediction performance for predicting fatty acid content and composition (n=1020 lambs) and pH (n=2406 lambs). Practical considerations of reference meat quality data quality and validation strategies are discussed. HSI can be used to predict meat quality parameters of lamb LL with varying accuracy levels, but ongoing calibration and validation across seasons is required to improve robustness of HSI for objective non-invasive assessment of lamb meat quality.
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Affiliation(s)
- C R Craigie
- AgReserach Food and Bio-based products group, Ruakura Research Centre, 10 Bisley Road, Hamilton 3214, New Zealand.
| | - P L Johnson
- AgReserach Animal Science group, Invermay Agricultural Centre, Puddle Alley, Mosgiel 9092, New Zealand
| | - P R Shorten
- AgReserach Farm Systems and Environment group, Ruakura Research Centre, 10 Bisley Road, Hamilton 3214, New Zealand; Riddet Institute, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand
| | - A Charteris
- Aimee Charteris Genetics Limited, Napier 4140, New Zealand
| | - G Maclennan
- Alliance Group Limited, 51 Don Street, Invercargill 9810, New Zealand
| | - M L Tate
- Alliance Group Limited, 51 Don Street, Invercargill 9810, New Zealand
| | - M P Agnew
- AgReserach Food and Bio-based products group, Ruakura Research Centre, 10 Bisley Road, Hamilton 3214, New Zealand
| | - K R Taukiri
- AgReserach Food and Bio-based products group, Ruakura Research Centre, 10 Bisley Road, Hamilton 3214, New Zealand
| | - A D Stuart
- AgReserach Food and Bio-based products group, Ruakura Research Centre, 10 Bisley Road, Hamilton 3214, New Zealand; Alliance Group Limited, 51 Don Street, Invercargill 9810, New Zealand
| | - M M Reis
- AgReserach Food and Bio-based products group, Ruakura Research Centre, 10 Bisley Road, Hamilton 3214, New Zealand
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2
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Oguin TH, Sharma S, Stuart AD, Duan S, Scott SA, Jones CK, Daniels JS, Lindsley CW, Thomas PG, Brown HA. Phospholipase D facilitates efficient entry of influenza virus, allowing escape from innate immune inhibition. J Biol Chem 2014; 289:25405-17. [PMID: 25065577 DOI: 10.1074/jbc.m114.558817] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Lipid metabolism plays a fundamental role during influenza virus replication, although key regulators of lipid-dependent trafficking and virus production remain inadequately defined. This report demonstrates that infection by influenza virus stimulates phospholipase D (PLD) activity and that PLD co-localizes with influenza during infection. Both chemical inhibition and RNA interference of PLD delayed viral entry and reduced viral titers in vitro. Although there may be contributions by both major isoenzymes, the effects on viral infectivity appear to be more dependent on the PLD2 isoenzyme. In vivo, PLD2 inhibition reduced virus titer and correlated with significant increases in transcription of innate antiviral effectors. The reduction in viral titer downstream of PLD2 inhibition was dependent on Rig-I (retinoic acid-inducible gene-1), IRF3, and MxA (myxovirus resistance gene A) but not IRF7. Inhibition of PLD2 accelerated the accumulation of MxA in foci as early as 30 min postinfection. Together these data suggest that PLD facilitates the rapid endocytosis of influenza virus, permitting viral escape from innate immune detection and effectors that are capable of limiting lethal infection.
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Affiliation(s)
- Thomas H Oguin
- From the Department of Immunology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-3678, Department of Biological Sciences, University of Memphis, Memphis, Tennessee 38152
| | - Shalini Sharma
- Department of Veterinary Physiology and Biochemistry, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar 125004, Haryana, India
| | - Amanda D Stuart
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
| | - Susu Duan
- From the Department of Immunology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-3678
| | | | - Carrie K Jones
- Departments of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232-0697
| | - J Scott Daniels
- Departments of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232-0697
| | - Craig W Lindsley
- Departments of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232-0697 Department of Chemistry and The Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232, and
| | - Paul G Thomas
- From the Department of Immunology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-3678,
| | - H Alex Brown
- Departments of Pharmacology and Department of Chemistry and The Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232, and Biochemistry, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6600,
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3
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Wise HM, Hutchinson EC, Jagger BW, Stuart AD, Kang ZH, Robb N, Schwartzman LM, Kash JC, Fodor E, Firth AE, Gog JR, Taubenberger JK, Digard P. Identification of a novel splice variant form of the influenza A virus M2 ion channel with an antigenically distinct ectodomain. PLoS Pathog 2012; 8:e1002998. [PMID: 23133386 PMCID: PMC3486900 DOI: 10.1371/journal.ppat.1002998] [Citation(s) in RCA: 162] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Accepted: 09/13/2012] [Indexed: 01/25/2023] Open
Abstract
Segment 7 of influenza A virus produces up to four mRNAs. Unspliced transcripts encode M1, spliced mRNA2 encodes the M2 ion channel, while protein products from spliced mRNAs 3 and 4 have not previously been identified. The M2 protein plays important roles in virus entry and assembly, and is a target for antiviral drugs and vaccination. Surprisingly, M2 is not essential for virus replication in a laboratory setting, although its loss attenuates the virus. To better understand how IAV might replicate without M2, we studied the reversion mechanism of an M2-null virus. Serial passage of a virus lacking the mRNA2 splice donor site identified a single nucleotide pseudoreverting mutation, which restored growth in cell culture and virulence in mice by upregulating mRNA4 synthesis rather than by reinstating mRNA2 production. We show that mRNA4 encodes a novel M2-related protein (designated M42) with an antigenically distinct ectodomain that can functionally replace M2 despite showing clear differences in intracellular localisation, being largely retained in the Golgi compartment. We also show that the expression of two distinct ion channel proteins is not unique to laboratory-adapted viruses but, most notably, was also a feature of the 1983 North American outbreak of H5N2 highly pathogenic avian influenza virus. In identifying a 14th influenza A polypeptide, our data reinforce the unexpectedly high coding capacity of the viral genome and have implications for virus evolution, as well as for understanding the role of M2 in the virus life cycle. Influenza A virus is a pathogen capable of infecting a wide range of avian and mammalian hosts, causing seasonal epidemics and pandemics in humans. In recent years, the unexpected coding capacity of the virus has begun to be unravelled, with the identification of three more protein products (PB1-F2, PB1-N40 and PA-X) on top of the 10 viral proteins originally identified 30 years ago. Here, we identify a 14th primary translation product, made from segment 7. Previously established protein products from segment 7 include the matrix (M1) and ion channel (M2) proteins. M2, made from a spliced transcript, has multiple roles in the virus lifecycle including in entry and budding. In a laboratory setting, it is possible to generate M2 deficient viruses, but these are highly attenuated. However, upon serial passage a virus lacking the M2 splice donor site quickly recovered wild type growth properties, without reverting the original mutation. Instead we found a compensatory single nucleotide mutation had upregulated another segment 7 mRNA. This mRNA encoded a novel M2-like protein with a variant extracellular domain, which we called M42. M42 compensated for loss of M2 in tissue culture cells and animals, although it displayed some differences in subcellular localisation. Our study therefore identifies a further novel influenza protein and gives insights into the evolution of the virus.
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MESH Headings
- Alternative Splicing
- Animals
- Birds
- Cell Line, Tumor
- Disease Outbreaks
- Dogs
- Humans
- Influenza A Virus, H5N2 Subtype/genetics
- Influenza A Virus, H5N2 Subtype/metabolism
- Influenza in Birds/epidemiology
- Influenza in Birds/genetics
- Influenza in Birds/metabolism
- Influenza, Human/epidemiology
- Influenza, Human/genetics
- Influenza, Human/metabolism
- Mice
- Mice, Inbred BALB C
- North America/epidemiology
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- RNA, Viral/biosynthesis
- RNA, Viral/genetics
- Viral Matrix Proteins/biosynthesis
- Viral Matrix Proteins/genetics
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Affiliation(s)
- Helen M. Wise
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge, United Kingdom
- The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
| | - Edward C. Hutchinson
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Brett W. Jagger
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge, United Kingdom
- Viral Pathogenesis and Evolution Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Amanda D. Stuart
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Zi H. Kang
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Nicole Robb
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Louis M. Schwartzman
- Viral Pathogenesis and Evolution Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - John C. Kash
- Viral Pathogenesis and Evolution Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ervin Fodor
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Andrew E. Firth
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Julia R. Gog
- DAMTP, Centre for Mathematical Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Jeffery K. Taubenberger
- Viral Pathogenesis and Evolution Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Paul Digard
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge, United Kingdom
- The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
- * E-mail:
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4
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Sobo K, Rubbia-Brandt L, Brown TDK, Stuart AD, McKee TA. Decay-accelerating factor binding determines the entry route of echovirus 11 in polarized epithelial cells. J Virol 2011; 85:12376-86. [PMID: 21917947 PMCID: PMC3209408 DOI: 10.1128/jvi.00016-11] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Accepted: 09/04/2011] [Indexed: 01/21/2023] Open
Abstract
The interaction between echovirus 11 strain 207 (EV11-207) and decay-accelerating factor (DAF or CD55) at the apical surface of polarized Caco-2 cells results in rapid transport of the virus to tight junctions and in its subsequent uptake. A virus mutant (EV11-207R) which differs at 6 amino acids and whose affinity for DAF is apparently significantly lower remains at the apical surface, from where its uptake occurs. Binding of EV11-207 to DAF and its transport to tight junctions result in a loss of function of the junctions. In contrast, the mutant virus EV11-207R is not transferred to tight junctions, nor does it impair the integrity of these junctions. Cholesterol depletion from the apical membrane leads to DAF aggregation and, presumably, internalization and inhibits infection by EV11-207. However, infection by EV11-207R is significantly less sensitive to cholesterol depletion than infection by EV11-207, confirming the DAF requirement for EV11-207, but not EV11-207R, to infect cells. These data strongly indicate that in the case of infection of polarized epithelial cells by echovirus 11, DAF binding appears be a key determinant in the choice of entry pathway, at least in cell culture.
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Affiliation(s)
- Komla Sobo
- Department of Clinical Pathology, University of Geneva, 1 Rue Michel Servet, 1211 Geneva 4, Switzerland.
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5
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Sobo K, Stuart AD, Rubbia-Brandt L, Brown TDK, McKee TA. Echovirus 11 infection induces dramatic changes in the actin cytoskeleton of polarized Caco-2 cells. J Gen Virol 2011; 93:475-487. [PMID: 22090210 DOI: 10.1099/vir.0.037697-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Binding of echovirus 11 strain 207 (EV11-207) to Caco-2 monolayers results in rapid transfer of the virus to tight junctions prior to uptake. Using a confocal microscopy based-method, this study quantified the spatiotemporal distribution of actin during the time course of infection by EV11-207 in Caco-2 polarized cells. It was found that binding of EV11-207 to the apical surface resulted in rapid rearrangement of the actin cytoskeleton, concomitant with transport of the virus particles to tight junctions. By interfering with the actin network dynamics, the virus remained trapped at the cell surface, leading to abortion of infection. In addition, it was observed that at 4 h post-infection, concomitant with the detection of virus replication, actin filament was depolymerized and degraded. Finally, it was shown that the mechanisms leading to loss of actin were independent of viral genome synthesis, indicating a potential role for the viral protein synthesis seen in late infection. These data confirmed a previous study on the requirement for an intact actin cytoskeleton for EV11-207 to infect cells and reinforce the notion of actin cytoskeleton subversion by picornaviruses during infection in polarized epithelial cells.
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Affiliation(s)
- Komla Sobo
- Division of Virology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK.,Cell Biology Unit, MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK.,Department of Clinical Pathology, University of Geneva, 1 Rue Michel Servet, 1211 Geneva 4, Switzerland
| | - Amanda D Stuart
- Division of Virology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Laura Rubbia-Brandt
- Department of Clinical Pathology, University of Geneva, 1 Rue Michel Servet, 1211 Geneva 4, Switzerland
| | - T David K Brown
- Division of Virology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Thomas A McKee
- Department of Clinical Pathology, University of Geneva, 1 Rue Michel Servet, 1211 Geneva 4, Switzerland
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6
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Bruce EA, Medcalf L, Crump CM, Noton SL, Stuart AD, Wise HM, Elton D, Bowers K, Digard P. Budding of filamentous and non-filamentous influenza A virus occurs via a VPS4 and VPS28-independent pathway. Virology 2009; 390:268-78. [PMID: 19524996 DOI: 10.1016/j.virol.2009.05.016] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 04/02/2009] [Accepted: 05/08/2009] [Indexed: 12/18/2022]
Abstract
The mechanism of membrane scission during influenza A virus budding has been the subject of controversy. We confirm that influenza M1 binds VPS28, a subunit of the ESCRT-1 complex. However, confocal microscopy of infected cells showed no marked colocalisation between M1 and VPS28 or VPS4 ESCRT proteins, or relocalisation of the cellular proteins. Trafficking of HA and M1 appeared normal when endosomal sorting was impaired by expression of inactive VPS4. Overexpression of either isoform of VPS28 or wildtype or dominant negative VPS4 proteins did not alter production of filamentous virions. SiRNA depletion of endogenous VPS28 had no significant effect on influenza virus replication. Furthermore, cells expressing wildtype or dominant-negative VPS4 replicated filamentous and non-filamentous strains of influenza to similar titres, indicating that influenza release is VPS4-independent. Overall, we see no role for the ESCRT pathway in influenza virus budding and the significance of the M1-VPS28 interaction remains to be determined.
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Affiliation(s)
- Emily A Bruce
- Division of Virology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
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7
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Abstract
Feline calicivirus (FCV) is a major causative agent of respiratory disease in cats. It is also one of the few cultivatable members of the family Caliciviridae. It has recently been reported that FCV binding is in part due to interaction with junction adhesion molecule-A. This report describes the characterization of additional receptor components for FCV. Chemical treatment of cells with sodium periodate showed that FCV recognized carbohydrate moieties on the surface of permissive cells. Enzymic treatment with Vibrio cholerae neuraminidase demonstrated that sialic acid was a major determinant of virus binding. Further characterization using linkage-specific lectins from Maackia amurensis and Sambucus nigra revealed that FCV recognized sialic acid with an alpha2,6 linkage. Using various proteases and metabolic inhibitors, it was shown that alpha2,6-linked sialic acid recognized by FCV is present on an N-linked glycoprotein.
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Affiliation(s)
- Amanda D Stuart
- Division of Virology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - T David K Brown
- Division of Virology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
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8
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Abstract
This study explores the experiences of four adolescents, each living with a parent who has sustained a traumatic brain injury, against the theoretical backdrop of existential-phenomenological psychology.
Opsomming
Hierdie navorsing verken die belewenisse van vier adolessente wat saam met ‘n ouer wat ‘n traumatiese breinbesering opgedoen het, leef.
*Please note: This is a reduced version of the abstract. Please refer to PDF for full text.
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9
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Abstract
Feline calicivirus is a major causative agent of respiratory disease in cats. It is also one of the few cultivatable members of Caliciviridae. We have examined the entry process of feline calicivirus (FCV). An earlier study demonstrated that acidification in endosomes may be required. We have confirmed this observation and expanded upon it, demonstrating, using drugs to inhibit the various endocytic pathways and dominant-negative mutants, that FCV infects cells via clathrin-mediated endocytosis. We have also observed that FCV permeabilizes cell membranes early during infection to allow the co-entry of toxins such as alpha-sarcin. Inhibitors of endosome acidification such as chloroquine and bafilomycin A1 blocked this permeabilization event, demonstrating that acidification is required for uncoating of the genome and access to the cytoplasm.
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Affiliation(s)
- Amanda D Stuart
- Division of Virology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, United Kingdom.
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10
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Stuart AD. Editorial Comments/ Redaksionele Kommentaar. Health SA 2005. [DOI: 10.4102/hsag.v10i3.196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
This edition of Health SA Gesondheid reflects the dichotomous, reciprocal and holistic natures of the two disciplines which are well represented in this Journal namely Psychology and Nursing Science.
Opsomming
Hierdie uitgawe van Heath SA Gesondheid reflekteer die tweeledigheid, resiprokaliteit en holisme van twee dissiplines wat sterk in die joernaal verteenwoordig word, naamlik Sielkunde en Verpleegkunde.
*Please note: This is a reduced version of the abstract. Please refer to PDF for full text.
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11
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Pretorius HG, Goldstein N, Stuart AD. Meaning-making of a group of South Africans in their experience of living with HIV: a phenomenological study. Health SA 2005. [DOI: 10.4102/hsag.v10i1.187] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
With the primary focus of disease specific studies on the medical and biological transmission and progression of HIV/AIDS, the lived experience and meaning-making of individuals who live with this disease, is a literary scarcity.
Opsomming
Met die primêre fokus van siektespesifieke studies op die mediese en ook biologiese oordrag en progressie van MIV/VIGS, is daar ‘n literêre skaarste oor die geleefde ondervinding en betekenisgewing van individue wat met hierdie siekte leef.
*Please note: This is a reduced version of the abstract. Please refer to PDF for full text.
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12
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Abstract
On reviewing the literature on spinal cord injury (SCI) and sexuality in males, there was found to be a plethora of research in physical domains.
Opsomming
Die studie van literatuur oor rugmurgbesering (RMB) en seksualiteit by mans, het ‘n magdom navorsing oor die fisieke aspekte opgelewer.
*Please note: This is a reduced version of the abstract. Please refer to PDF for full text.
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13
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Stuart AD. Editorial Comments/ Redaksionele Kommentaar. Health SA 2003. [DOI: 10.4102/hsag.v8i2.120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
A theoretical ideal for the sciences as propagated by the Ancient Greeks, inter alia Aristotle, stated as basis Knowledge for the sake of Knowledge.
Opsomming
‘n Teoretiese ideaal vir wetenskap is reeds deur die Antieke
Grieke, onder andere Artistoleles, gepropageer, waar Kennis
ter wille van Kennis as grondslag gestel is.
*Please note: This is a reduced version of the abstract. Please refer to PDF for full text.
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14
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Abstract
An in-depth look is taken at the specific discourses surrounding the debilitating HIV/AIDS epidemic sweeping South Africa and the world.
Opsomming
Hierdie artikel poog om ‘n indiepte ondersoek te loods na die spesifieke diskoerse rondom die MIV/VIGS epidemie in Suid-Afrika en die wêreld.
*Please note: This is a reduced version of the abstract. Please refer to PDF for full text.
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15
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Macgregor J, Schoeman WJ, Stuart AD. The victim's experience of hijacking: an exploratory study. Health SA 2002. [DOI: 10.4102/hsag.v7i1.374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
This paper summarises a phenomenological study that was designed to explore the victim's lived experience of
undergoing a motor vehicle hijacking. OpsommingHierdie artikel verskaf 'n oorsig oor 'n fenomenologiese studio wat ontwerp is om die slagofferse geleefde ervaring van 'n motorkaping te ondersoek.
*Please note: This is a reduced version of the abstract. Please refer to PDF for full text.
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16
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Abstract
The glycosylphosphatidylinositol (GPI)-anchored complement regulatory protein decay-accelerating factor (DAF) is used by a number of enteroviruses as a receptor during infection. DAF and other GPI-anchored proteins can be found in cholesterol-rich ordered domains within the plasma membrane that are known as "lipid rafts." We have shown, by using drugs to specifically inhibit various endocytosis routes, that infection by a DAF-using strain of echovirus 11 (EV11) is dependent upon cholesterol and an intact cytoskeleton, whereas a non-DAF-using mutant derived from it was unaffected by these drugs. Using RNA transfection and virus-binding assays, we have shown that this requirement for cholesterol, the actin cytoskeleton, and the microtubule network occurs postbinding of the virus but prior to uncoating of the RNA, indicating a role during virus entry. Confocal microscopy of virus infection supported the role of cholesterol and the cytoskeleton during entry. In addition, [(35)S]methionine-labeled DAF-using EV11, but not the non-DAF-using EV11, could be copurified with lipid raft components during infection after Triton X-100 extraction. These data indicate that DAF usage by EV11 enables the virus to associate with lipid rafts and enter cells through this novel route.
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Affiliation(s)
- Amanda D Stuart
- Division of Virology, Department of Pathology, University of Cambridge, CB2 1QP Cambridge, United Kingdom.
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17
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Stuart AD, McKee TA, Williams PA, Harley C, Shen S, Stuart DI, Brown TDK, Lea SM. Determination of the structure of a decay accelerating factor-binding clinical isolate of echovirus 11 allows mapping of mutants with altered receptor requirements for infection. J Virol 2002; 76:7694-704. [PMID: 12097583 PMCID: PMC136386 DOI: 10.1128/jvi.76.15.7694-7704.2002] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have used X-ray crystallography to determine the structure of a decay accelerating factor (DAF)-binding, clinic-derived isolate of echovirus 11 (EV11-207). The structures of the capsid proteins closely resemble those of capsid proteins of other picornaviruses. The structure allows us to interpret a series of amino acid changes produced by passaging EV11-207 in different cell lines as highlighting the locations of multiple receptor-binding sites on the virion surface. We suggest that a DAF-binding site is located at the fivefold axes of the virion, while the binding site for a distinct but as yet unidentified receptor is located within the canyon surrounding the virion fivefold axes.
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Affiliation(s)
- Amanda D Stuart
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
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18
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Salek-Ardakani S, Stuart AD, Arrand JE, Lyons S, Arrand JR, Mackett M. High level expression and purification of the Epstein-Barr virus encoded cytokine viral interleukin 10: efficient removal of endotoxin. Cytokine 2002; 17:1-13. [PMID: 11886166 DOI: 10.1006/cyto.2001.0990] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To characterize the structural and functional properties of viral interleukin 10 (vIL-10), its cDNA was cloned into the bacterial expression vector pMAL-c2, which directs the synthesis of the inserted gene as a fusion protein with maltose binding protein (MBP). The MBP-vIL-10 fusion protein was expressed in Escherichia coli and purified from cell lysates using amylose resin chromatography. Viral interleukin 10 (IL-10) was released from the fusion protein by cleavage with the proteolytic enzyme factor Xa. We show that vIL-10 will bind to heparin and use this property to purify vIL-10 from factor Xa cleaved products and trace contaminants using heparin agarose chromatography. A simple one-step procedure is described for the removal of endotoxins from heavily contaminated vIL-10 preparations. The protocol exploits the high binding affinity of MBP for amylose resin or vIL-10 for heparin and the ability of Triton-X114 to dissociate endotoxins from proteins. The biological activity of purified vIL-10 was demonstrated through its ability to inhibit interferon gamma (IFN-gamma) production by mitogen activated peripheral blood mononuclear cells and to down-regulate HLA-class II expression on activated monocytes/macrophages. The availability of an efficient expression and purification strategy for vIL-10 together with appropriate assays will contribute to a greater understanding of how vIL-10 has evolved to retain and modify those activities of cellular IL-10 best suited for Epstein-Barr virus (EBV)'s specialized niche within the host.
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Affiliation(s)
- Shahram Salek-Ardakani
- Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Wilmslow Road, Withington, Manchester, M20 4BX, UK.
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Stuart AD, Stewart JP, Arrand JR, Mackett M. The Epstein-Barr virus encoded cytokine viral interleukin-10 enhances transformation of human B lymphocytes. Oncogene 1995; 11:1711-9. [PMID: 7478598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In vitro infection of human B lymphocytes with Epstein-Barr virus (EBV) results in their growth transformation and establishment of immortalised lymphoblastoid cell lines. The virus was recently found to encode a homologue of the pleitropic cytokine interleukin-10 (IL-10), which has wide ranging effects on the immune system. We have investigated the effect of this virally encoded growth factor on the ability of EBV to immortalize B lymphocytes from tonsils and from adult and neonatal blood. Recombinant viral interleukin-10 (vIL-10) was found to increase dramatically the growth transformation of B cells from all three populations infected with either the highly transforming type 1 strain B95-8 or the less efficient type 2 strain BL16. This striking enhancement of transforming ability in the presence of viral IL-10 may be in part due to increased viability of the B cells during infection and decreased levels of interferon-gamma, a cytokine known to inhibit EBV transformation. Thus viral IL-10 influences a number of cell types of the immune system to allow the enhanced outgrowth of EBV transformed cells.
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Affiliation(s)
- A D Stuart
- Department of Molecular Biology, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Withington, Manchester
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Littler E, Stuart AD, Chee MS. Human cytomegalovirus UL97 open reading frame encodes a protein that phosphorylates the antiviral nucleoside analogue ganciclovir. Nature 1992; 358:160-2. [PMID: 1319559 DOI: 10.1038/358160a0] [Citation(s) in RCA: 289] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Human cytomegalovirus (HCMV, a betaherpes virus) is the cause of serious disease in immunologically compromised individuals, including those with acquired immunodeficiency syndrome. One of the compounds used in the chemotherapy of HCMV infections is the nucleoside analogue 9-(1,3-dihydroxy-2-propoxymethyl)-guanine (ganciclovir). The mechanism of action of this drug is dependent on the formation of the nucleoside triphosphate, which is a strong inhibitor of the viral DNA polymerase. Thymidine kinase, which is encoded by many of the herpesviruses, catalyses the initial phosphorylation of ganciclovir. But there is no evidence for the coding of this enzyme by HCMV, and DNA sequence analysis of the HCMV genome has shown that there is no open reading frame characteristic of a herpesvirus thymidine kinase. Here we present biochemical and immunological evidence that the HCMV UL97 open reading frame codes for a protein capable of phosphorylating ganciclovir. This protein seems to be responsible for the selectivity of ganciclovir and will be useful tool in the understanding and refinement of the antiviral activity of new selective anti-HCMV compounds.
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Affiliation(s)
- E Littler
- Department of Molecular Sciences, Wellcome Research Laboratories, Beckenham, Kent, UK
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Chiu CKF, Mander LN, Stuart AD, Willis AC. An Approach to the Total Synthesis of Diterpenoid Plant Growth Substances Isolated From Gametophytes of the Fern Genus Anemia. Aust J Chem 1992. [DOI: 10.1071/ch9920227] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Reduction of the oxoindan acid (9) by potassium in liquid ammonia followed by in situ alkylation with 3-methylbut-2-enyl bromide furnished enol ether (14) which was transformed into the acetal (17) and thence aldehydes (18; R = COCH3 and COCHCl2). Acid- catalysed aldol reactions then afforded the ethanoindene derivatives (19; R=COCH3 and COCHCl2). Further elaboration gave carbinol (28) which is envisaged as an intermediate for the total synthesis of the diterpenoid antheridiogens obtained from gametophytes of the fern genus Anemia, including acid (2). The relative stereochemistry of acetal (17) was established by X-ray crystallographic analysis.
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Croft KD, Ghisalberti EL, Jefferies PR, Stuart AD. The Chemistry of Eremophila spp. XI. The Absolute Configuration of Dihydroxyserrulatic Acid. Aust J Chem 1979. [DOI: 10.1071/ch9792079] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Dihydroxyserrulatic acid (1),
a diterpene from Eremophila serrulata,
has been degraded to the naphthalene (2) which was shown to have the R-configuration. The diterpene acid can
now be designated as (5R,8S,1'S)-4-hydroxy-8-(6'-hydroxy-1',5'-dimethylhex-4-enyl)-5-methyl-5,6,7,8-tetrahydronaphthalene-2-carboxylic
acid.
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Abstract
The proposed structure for
a phenolic sesquiterpene, 2-(11,5?- dimethylhex-4?-enyl)-4-methylphenol (1),
previously isolated from Elvira biflora, has been
confirmed by synthesis of its racemate in 3 steps from 3-bromo-4-methoxytoluene
and 6-methylhept-5-en-2-one. A structural isomer, 4-(1?,5?-di-methylhex-4?-enyl)-2-methylphenol
(4), has also been synthesized for spectral comparison, since the natural
product and the synthetic racemate (1) were only able to be compared by N.M.R.
spectroscopy.
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