66 resultados para Proteomic screen
Resumo:
It is widely recognized that 'asymptomatic' patients with coeliac disease often feel better after commencing a gluten-free diet. The aim of this study was to determine a measure of the quality of life in patients diagnosed as having coeliac disease detected both by screening and those with typical clinical symptoms.
Resumo:
Trichinella spiralis is an intracellular nematode parasite of mammalian skeletal muscle. Infection of the muscle cell leads to the formation of a host-parasite complex that results in profound alterations to the host cell and a re-alignment of muscle-specific gene expression. The role of parasite excretory-secretory (ES) proteins in mediating these effects is currently unknown, largely due to the difficulty in identifying and assigning function to individual proteins. In this study, a global proteomics approach was used to analyse the ES proteins from T. spiralis muscle larvae. Following 2-DE of ES proteins,MALDI-TOF-MS and LC-MS/MS were used to identify the peptide spots. Specific Trichinella EST databases were assembled and used to analyse the data. Despite the current absence of a Trichinella genome-sequencing project, 43 out of 52 protein spots analysed were identified and included the major secreted glycoproteins. Other novel proteins were identified from matches with sequences in the T. spiralis database. Our results demonstrate the value of proteomics as a tool for the identification of Trichinella ES proteins and in the study of the molecular mechanism underpinning the formation of the host-parasite complex during Trichinella infections.
Resumo:
Prostate cancer is the most commonly diagnosed cancer in men. Evidence suggests that smokers may be at increased risk of prostate cancer compared to non-smokers. In the present study we ask whether adult men who smoke are also less likely to undergo screening for prostate cancer. Adult men aged 46 and above completed a single questionnaire including demographic items and items concerning their smoking status and previous testing for prostate cancer. The questionnaire also included an 11 item numeracy scale. Compared to smokers, non-smokers and ex-smokers were around two times more likely to have undergone screening for prostate cancer, and had been tested more frequently. Smokers are not only more likely to develop prostate cancer, they are, paradoxically, less likely to undergo screening for prostate cancer. Health care professionals need to be cognizant of individual differences in screening behavior and that smokers have a reduced likelihood of choosing to screen. © 2012 Elsevier Ltd.
Comparison of frequency-selective screen-based linear to circular split-ring polarisation convertors
Resumo:
This study presents the use of periodic arrays of freestanding slot frequency-selective screens (FSS) as a means for generating circularly polarised signals from an incident linearly polarised signal at normal incidence to the structure. Measured and simulated results for crossed, linear and various ring slot element shapes in single and double-layer polarisation convertor structures are presented for 10 GHz operation. It is shown that 3 dB axial ratio (AR) bandwidths of 21% can be achieved with the one-layer perforated screen design and that the rate of change is lower than the double-layer structures. An insertion loss of 0.34 dB can be achieved for the split circular ring double-layer periodic array, and of the three topologies presented the hexagonal split-ring polarisation convertor gives the lowest variation of AR with angle of incidence 1.8 dB/45° and 3.6 dB/45° for the single and double-screen FSS, respectively. In addition, their tolerance to angle of incidence variation is presented. The capability of the surfaces reported here as twist polariser or spatial isolator components has been demonstrated with up to -30 dB isolation between incident and re-reflected signals for the double-layer designs being measured. © 2010 The Institution of Engineering and Technology.
Resumo:
Unregulated growth promoter use in food-producing animals is an issue of concern both from food safety and animal welfare perspectives. However, the monitoring of such practices is analytically challenging due to the concerted actions of users to evade detection. Techniques based on the monitoring of biological responses to exogenous administrations have been proposed as more sensitive methods to identify treated animals. This study has, for the first time, profiled plasma proteome responses in bovine animals to treatment with nortestosterone decanoate and 17 beta-oestradiol benzoate, followed by dexamethasone administration. Two-dimensional fluorescence differential in-gel electrophoresis analysis revealed a series of hepatic and acute-phase proteins within plasma whose levels were up- or down-regulated within phases of the treatment regime. Surface plasmon resonance (SPR) immuno-assays were developed to quantify responses of identified protein markers during the experimental treatment study with a view to developing methods which can be used as screening tools for growth promoter abuse detection. SPR analysis demonstrated the potential for plasma proteins to be used as indicative measures of growth promoter administrations and concludes that the sensitivity and robustness of any detection approach based on plasma proteome analysis would benefit from examination of a range of proteins representative of diverse biological processes rather being reliant on specific individual markers.
Resumo:
Histone methylation is a dynamic and reversible process proposed to directly impact on stem cell fate. The Jumonji (JmjC) domain-containing family of demethylases comprises 27 members which can demethylate mono-, di- and tri-methylated lysine residues of histone (or non-histone) targets. To evaluate their role in regulation of hematopoietic stem cell (HSC) behaviour we performed a RNAi-based screen and found that demethylases JARID1B (H3K4) and JHDM1F (H3K9) play opposing roles in regulation of HSC activity. Decrease in Jarid1b levels correlated with an in vitro expansion of HSC with preserved long term in vivo lympho-myeloid differentiation potential. Jarid1b knockdown was associated with an increase in expression levels of 5’ Hoxa cluster genes and CxCl5 , and reduced levels of Pu.1, Egr1 and Cav1. shRNA against Jhdmlf, in contrast, impaired hematopoietic reconstitution of bone marrow cells. Together, our studies identified Jarid1b as a negative, and Jhdmlf as a positive regulator of HSC activity.
Resumo:
Metastasis accounts largely for the high mortality rate of colorectal cancer (CRC) patients. In this study, we performed comparative proteome analysis of primary CRC cell lines HCT-116 and its metastatic derivative E1 using 2-D DIGE. We identified 74 differentially expressed proteins, many of which function in transcription, translation, angiogenesis signal transduction, or cytoskeletal remodeling pathways, which are indispensable cellular processes involved in the metastatic cascade. Among these proteins, stathmin-1 (STMN1) was found to be highly up-regulated in E1 as compared to HCT-116 and was thus selected for further functional studies. Our results showed that perturbations in STMN1 levels resulted in significant changes in cell migration, invasion, adhesion, and colony formation. We further showed that the differential expression of STMN1 correlated with the cells' metastatic potential in other paradigms of CRC models. Using immunohistochemistry, we also showed that STMN1 was highly expressed in colorectal primary tumors and metastatic tissues as compared to the adjacent normal colorectal tissues. Furthermore, we also showed via tissue microarray analyses of 324 CRC tissues and Kaplan-Meier survival plot that CRC patients with higher expression of STMN1 have poorer prognosis.
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One of the main applications of serum proteomics is the identification of new biomarkers for animal disease or animal production. However, potential obstacles to these studies are the poor performance of affinity serum depletion methods based on human antigens when using animal samples, and loss of minor serum components bound to albumin and other proteins. In the present study, we have analyzed the efficiency and reproducibility of the ProteoMiner® beads with bovine and porcine serum samples, and compared to a traditional immunoaffinity-based albumin and IgG depletion system specific for human samples. The ProteoMiner kit is based on the use of a combinatorial peptide binding library and intends to enrich low-abundance proteins.
Resumo:
Three groups of cows representing three ranges of welfare in the production system were included in the study: two groups of Bruna dels Pirineus beef cattle maintained under different management systems (good and semiferal conditions) and a group of Alberes cows, a breed that lives in the mountains (hardest conditions).
In order to identify new stress/welfare biomarkers, serum from Bruna cows living in both environments was subjected to DIGE labelling, two-dimensional electrophoresis and MALDI-MS or ion trap MS. Identification was achieved for 15 proteins, which mainly belonged to three biological functions, the oxidative stress pathway (glutathione peroxidase (GPx) and paraoxonase (PON-1)), the acute phase protein family (Heremans Schmid glycoprotein alpha2 (α2-HSG)) and the complement system.
Biological validation included the Alberes breed. GPx and PON-1 were validated by an enzymatic assay and found to be higher and lower, respectively, in cows living in hard conditions. α2-HSG was validated by ELISA and found to be reduced in hard conditions. Other biomarkers of the redox status were also altered by living conditions: protein carbonyl content, superoxide dismutase (SOD) and glutathione reductase (GR).
Our results show that changes in the redox system are the main adaptation of cows living in challenging environmental conditions. This article is part of a Special Issue entitled: “Farm animal proteomics”.
Resumo:
Growth-promoting agents are continually misused for increasing animal growth and fraudulent gain in the meat industry, yet detection rates from conventional targeted testing for drug residues do not reflect this. This is because testing currently relies on direct detection of drugs or related metabolites and administrators of such compounds can take adaptive measures to avoid detection through the use of endogenous or unknown drugs, and low dose or combined mixtures. New detection methods are needed which focus on the screening of biological responses of an animal to such growth-promoting agents as it has been demonstrated that genomic, proteomic and metabolomics profiles are altered by xenobiotic intake. Therefore, an untargeted proteomics approach using comparative two-dimensional gel electrophoresis (2DE) was carried out to identify putative proteins altered in plasma after treatment with oestradiol, dexamethasone or prednisolone. Twenty-four male cattle were randomly assigned to four groups (n = 6) for experimental treatment over 40 days, namely a control group of non-treated cattle, and three groups administered 17β-oestradiol-3-benzoate (0.01 mg/kg, intramuscular), dexamethasone sodium phosphate (0.7 mg/day, per os) or prednisolone acetate (15 mg/day, per os), respectively. Plasma collected from each animal at day 25 post study initiation was subjected to proteomic analysis by 2DE for comparison of protein expression between treated and untreated animals. Analysis of acquired gel images revealed 22 plasma proteins which differed in expression by more than 50 % (p < 0.05) in treated animals compared to untreated animals. Proteins of interest underwent identification by LC–MS/MS analysis and were found to have associated roles in transport, blood coagulation, immune response and metabolism pathways. In this way, seven proteins are highlighted as novel biomarker candidates including transthyretin which is shown to be significantly increased in all treatment groups compared to control animals and potentially may find use as global markers of suspect anabolic practice.
Resumo:
The technological constraints of early British television encouraged drama productions which emphasised the immediate, the enclosed and the close-up, an approach which Jason Jacobs described in the title of his seminal study as 'the intimate screen'. While Jacobs' book showed that this conception of early British television drama was only part of the reality, he did not focus on the role that special effects played in expanding the scope of the early television screen. This article will focus upon this role, showing that special effects were not only of use in expanding the temporal and spatial scope of television, but were also considered to be of interest to the audience as a way of exploring the new medium, receiving coverage in the popular press. These effects included pre-recorded film inserts, pre-recorded narration, multiple sets, model work and animation, combined with the live studio performances. Drawing upon archival research into television production files and scripts as well as audience responses and periodical coverage of television at the time of broadcast, this article will focus on telefantasy. This genre offered particular opportunities for utilising effects in ways that seemed appropriate for the experimentation with the form of television and for the drama narratives. This period also saw a variety of shifts within television as the BBC sought to determine a specific identity and understand the possibilities for the new medium.
This research also incorporates the BBC's own research and internal dialogue concerning audiences and how their tastes should best be met, at a time when the television audience was not only growing in terms of number but was also expanding geographically and socially beyond the moneyed Londoners who could afford the first television sets and were within range of the Alexandra Palace transmissions. The primary case study for this article will be the 1949 production of H.G.Wells’ The Time Machine, which incorporated pre-recorded audio and film inserts, which expanded the narrative out of the live studio performance both temporally and spatially, with the effects work receiving coverage in the popular magazine Illustrated. Other productions considered will be the 1938 and 1948 productions of RUR, the 1948 production of Blithe Spirit, and the 1950 adaptation of The Strange Case of Dr Jekyll and Mr Hyde. Despite the focus on telefantasy, this article will also include examples from other genres, both dramatic and factual, showing how the BBC's response to the changing television audience was to restrict drama to a more 'realistic' aesthetic and to move experimentation with televisual form to non-drama productions such as variety performances.
Resumo:
Klebsiella pneumoniae is etiologic agent of community-acquired and nosocomial pneumonia. It has been shown that K. pneumoniae infections are characterized by reduced early inflammatory response. Recently our group have shown that K. pneumoniae dampens the activation of inflammatory responses by antagonizing the activation of the NF-κB canonical pathway. Our results revealed that K. pneumoniae capsule (CPS) was necessary but not sufficient to attenuate inflammation. To identify additional Klebsiella factors required to dampen inflammation, we standardized and applied a high-throughput gain-on-function screen to examine a Klebsiella transposon mutant library. We identified 114 mutants that triggered the activation of NF-κB. Two gene ontology categories accounted for half of the loci identified in the screening, that of metabolism and transport (32% of the mutants), and of enveloperelated genes (17%). Characterization of the mutants revealed that the lack of the enterobactin siderophore was linked to a reduced CPS expression which in turn underlined the NF- κB activation induced by the mutant. The lipopolysaccharide (LPS) O-polysaccharide and the pullulanase (PulA) type 2 secretion system (T2SS) are required for full effectiveness of immune evasion. Importantly, these factors do not play a redundant role. The fact that LPS Opolysaccharide and T2SS mutants-induced responses were dependent on TLR2-TLR4- MyD88 activation suggested that LPS Opolysaccharide and PulA perturbed TLRdependent recognition of K. pneumoniae. Finally, we demonstrate that LPS O-polysaccharide and pulA mutants are attenuated in the pneumonia mouse model. We propose that LPS Opolysaccharide and PulA T2SS could be new targets for designing new antimicrobials. Increasing TLR-governed defence responses might provide also selective alternatives for the management of K. pneumoniae pneumonia.