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Search Results: 1 - 10 of 201494 matches for " Clare P Wilkes "
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A microarray analysis of gene expression in the free-living stages of the parasitic nematode Strongyloides ratti
Fiona J Thompson, Gary LA Barker, Louise Hughes, Clare P Wilkes, Jane Coghill, Mark E Viney
BMC Genomics , 2006, DOI: 10.1186/1471-2164-7-157
Abstract: We have constructed an S. ratti cDNA microarray and used it to interrogate changes in gene expression during the free-living phase of the S. ratti life-cycle. We have found very extensive differences in gene expression between first-stage larvae (L1) passed in faeces and infective L3s preparing to infect hosts. In L1 stages there was comparatively greater expression of genes involved in growth. We have also compared gene expression in L2 stages destined to develop directly into infective L3s with those destined to develop indirectly into free-living adults. This revealed relatively small differences in gene expression. We find little evidence for the conservation of transcription profiles between S. ratti and S. stercoralis or C. elegans.This is the first multi-gene study of gene expression in S. ratti. This has shown that robust data can be generated, with consistent measures of expression within computationally determined clusters and contigs. We find inconsistencies between EST representation data and microarray hybridization data in the identification of genes with stage-specific expression and highly expressed genes. Many of the genes whose expression is significantly different between L1 and iL3s stages are unknown beyond alignments to predicted genes. This highlights the forthcoming challenge in actually determining the role of these genes in the life of S. ratti.Parasitic nematodes have complex life-cycles that are affected and controlled by factors both within and outwith their hosts. In the genus Strongyloides, the life-cycle, unusually, includes both an obligate female-only parasitic generation and a facultative dioecious adult free-living generation. In recent years there has been an increasingly detailed understanding of the factors that affect the development of the free-living phase of this life-cycle, particularly for the parasites of rats, S. ratti [1].S. ratti parasitic females lie embedded in the mucosa of the small intestine of their host. These
Immunological Responses Elicited by Different Infection Regimes with Strongyloides ratti
Steve Paterson, Clare Wilkes, Colin Bleay, Mark E. Viney
PLOS ONE , 2008, DOI: 10.1371/journal.pone.0002509
Abstract: Nematode infections are a ubiquitous feature of vertebrate life. In nature, such nematode infections are acquired by continued exposure to infective stages over a prolonged period of time. By contrast, experimental laboratory infections are typically induced by the administration of a single (and often large) dose of infective stages. Previous work has shown that the size of an infection dose can have significant effects on anti-nematode immune responses. Here we investigated the effect of different infection regimes of Strongyloides ratti, comparing single and repeated dose infections, on the host immune response that was elicited. We considered and compared infections of the same size, but administered in different ways. We considered infection size in two ways: the maximum dose of worms administered and the cumulative worm exposure time. We found that both infection regimes resulted in Th2-type immune response, characterised by IL4 and IL13 produced by S. ratti stimulated mesenteric lymph node cells, anti-S. ratti IgG1 and intestinal rat mast cell protease II (RMCPII) production. We observed some small quantitative immunological differences between different infection regimes, in which the concentration of IL4, IL13, anti-S. ratti IgG1 and IgG2a and RMCPII were affected. However, these differences were quantitatively relatively modest compared with the temporal dynamics of the anti-S. ratti immune response as a whole.
PfeIK1, a eukaryotic initiation factor 2α kinase of the human malaria parasite Plasmodium falciparum, regulates stress-response to amino-acid starvation
Clare Fennell, Shalon Babbitt, Ilaria Russo, Jonathan Wilkes, Lisa Ranford-Cartwright, Daniel E Goldberg, Christian Doerig
Malaria Journal , 2009, DOI: 10.1186/1475-2875-8-99
Abstract: The impact of starvation on the phosphorylation state of PfeIF2α was examined. Bioinformatic methods were used to identify plasmodial eIF2α kinases. The activity of one of these, PfeIK1, was investigated using recombinant protein with non-physiological substrates and recombinant PfeIF2α. Reverse genetic techniques were used to disrupt the pfeik1 gene.The data demonstrate that the Plasmodium falciparum eIF2α orthologue is phosphorylated in response to starvation, and provide bioinformatic evidence for the presence of three eIF2α kinases in P. falciparum, only one of which (PfPK4) had been described previously. Evidence is provided that one of the novel eIF2α kinases, PfeIK1, is able to phosphorylate the P. falciparum eIF2α orthologue in vitro. PfeIK1 is not required for asexual or sexual development of the parasite, as shown by the ability of pfeik1- parasites to develop into sporozoites. However, eIF2α phosphorylation in response to starvation is abolished in pfeik1- asexual parasitesThis study strongly suggests that a mechanism for versatile regulation of translation by several kinases with a similar catalytic domain but distinct regulatory domains, is conserved in P. falciparum.Human malaria is caused by infection with intracellular protozoan parasites of the genus Plasmodium that are transmitted by Anopheles mosquitoes. Of four species that infect humans, Plasmodium falciparum is responsible for the most virulent form of the disease. The transition from one stage of the life cycle to the next must be tightly regulated, to ensure proliferation and differentiation occur when and where appropriate; this is undoubtedly linked to differential gene expression. Analysis of the P. falciparum transcriptome during the erythrocytic asexual cycle reveals an ordered cascade of gene expression [1], and the various developmental stages display distinct transcriptomes; how this is orchestrated remains obscure. Initial investigation of the P. falciparum genome revealed a paucity
Complete genome sequence of an astrovirus identified in a domestic rabbit (Oryctolagus cuniculus) with gastroenteritis
Stenglein Mark D,Velazquez Eric,Greenacre Cheryl,Wilkes Rebecca P
Virology Journal , 2012, DOI: 10.1186/1743-422x-9-216
Abstract: A colony of domestic rabbits in Tennessee, USA, experienced a high-mortality (~90%) outbreak of enterocolitis. The clinical characteristics were one to six days of lethargy, bloating, and diarrhea, followed by death. Heavy intestinal coccidial load was a consistent finding as was mucoid enteropathy with cecal impaction. Preliminary analysis by electron microscopy revealed the presence of virus-like particles in the stool of one of the affected rabbits. Analysis using the Virochip, a viral detection microarray, suggested the presence of an astrovirus, and follow-up PCR and sequence determination revealed a previously uncharacterized member of that family. Metagenomic sequencing enabled the recovery of the complete viral genome, which contains the characteristic attributes of astrovirus genomes. Attempts to propagate the virus in tissue culture have yet to succeed. Although astroviruses cause gastroenteric disease in other mammals, the pathogenicity of this virus and the relationship to this outbreak remains to be determined. This study therefore defines a viral species and a potential rabbit pathogen.
Clues to Quasar Broad Line Region Geometry and Kinematics
M. Vestergaard,B. J. Wilkes,P. D. Barthel
Physics , 2000, DOI: 10.1086/312805
Abstract: We present evidence that the high-velocity CIV lambda 1549 emission line gas of radio-loud quasars may originate in a disk-like configuration, in close proximity to the accretion disk often assumed to emit the low-ionization lines. For a sample of 36 radio-loud z~2 quasars we find the 20--30% peak width to show significant inverse correlations with the fractional radio core-flux density, R, the radio axis inclination indicator. Highly inclined systems have broader line wings, consistent with a high-velocity field perpendicular to the radio axis. By contrast, the narrow line-core shows no such relation with R, so the lowest velocity CIV-emitting gas has an inclination independent velocity field. We propose that this low-velocity gas is located at higher disk-altitudes than the high-velocity gas. A planar origin of the high-velocity CIV-emission is consistent with the current results and with an accretion disk-wind emitting the broad lines. A spherical distribution of randomly orbiting broad-line clouds and a polar high-ionization outflow are ruled out.
ChaMP and the High Redshift Quasars in X-rays
S. Mathur,H. Marshall,N. Evans,P. Green,B. Wilkes
Physics , 2000,
Abstract: Chandra X-ray Observatory, (formerly known as AXAF), will observe down to the flux limit of 2\times 10^{-16} erg~s^{-1} cm^{-2}. In its first year of operation Chandra's CCD detectors will observe over 1500 quasars serendipitously in the soft (0.5--3.5 keV) band. Over 200 quasars will be detected in X-rays in the redshift range 3
The use of bupropion SR in cigarette smoking cessation
Scott Wilkes
International Journal of COPD , 2008,
Abstract: Scott WilkesDepartment of Primary and Community Care, School of Health, Natural and Social Sciences, University of Sunderland, Sunderland, United KingdomAbstract: Cigarette smoking remains the largest preventable cause of premature death in developed countries. Until recently nicotine replacement therapy (NRT) has been the only recognised form of treatment for smoking cessation. Bupropion, the first non-nicotine based drug for smoking cessation was licensed in the United States of America (US) in 1997 and in the United Kingdom (UK) in 2000 for smoking cessation in people aged 18 years and over. Bupropion exerts its effect primarily through the inhibition of dopamine reuptake into neuronal synaptic vesicles. It is also a weak noradrenalin reuptake inhibitor and has no effect on the serotonin system. Bupropion has proven efficacy for smoking cessation in a number of clinical trials, helping approximately one in five smokers to stop smoking. Up to a half of patients taking bupropion experience side effects, mainly insomnia and a dry mouth, which are closely linked to the nicotine withdrawal syndrome. Bupropion is rarely associated with seizures however care must be taken when co-prescribing with drugs that can lower seizure threshold. Also, bupropion is a potent enzyme inhibitor and can raise plasma levels of some drugs including antidepressants, antiarrhythmics and antipsychotics. Bupropion has been shown to be a safe and cost effective smoking cessation agent. Despite this, NRT remains the dominant pharmacotherapy to aid smoking cessation.Keywords: bupropion, smoking cessation, nicotine addiction
The pen behind the sword: power, literacy and the Roman army
John Wilkes
Archaeology International , 2001, DOI: 10.5334/ai.0510
Abstract: The creation and cohesion of the Roman empire owed much to the spread of literacy through the provinces and the use of texts as an instrument of government. An important manifestation of this is the role of the written word in the Roman army, exemplified by the diplomas that granted Roman citizenship and other privileges to auxiliary soldiers on completion of their military service. Margaret Roxan, one of the Institute's honorary research fellows, has studied these diplomas for many years, and her achievement was honoured at an international conference in London in May 2002.
Excavating the Spartans
John Wilkes
Archaeology International , 1997, DOI: 10.5334/ai.0108
Abstract: Few ancient Greek place names are so embedded in Western consciousness as Sparta, evoking as it does courage, harsh training, stern duty and endurance. Bythe 2nd century AD it had become a "heritage centre " admired by visiting Romans, and it flourished again in the Byzantine period. The Institute has been involved in new excavations at Sparta since 1989.
Profinite rigidity for Seifert fibre spaces
Gareth Wilkes
Mathematics , 2015,
Abstract: An interesting question is whether two 3-manifolds can be distinguished by computing and comparing their collections of finite covers; more precisely, by the profinite completions of their fundamental groups. In this paper, we solve this question completely for closed orientable Seifert fibre spaces. In particular, all Seifert fibre spaces are distinguished from each other by their profinite completions apart from some previously-known examples due to Hempel. We also characterize when bounded Seifert fibre space groups have isomorphic profinite completions, given some conditions on the boundary.
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