24 resultados para >250 µm, 11-18 specimens
Resumo:
Background: There is an urgent need to identify molecular signatures in small cell lung cancer (SCLC) that may select patients who are likely to respond to molecularly targeted therapies. In this study, we investigate the feasibility of undertaking focused molecular analyses on routine diagnostic biopsies in patients with SCLC.
Methods: A series of histopathologically confirmed formalin-fixed, paraffin-embedded SCLC specimens were analysed for epidermal growth factor receptors (EGFR), KRAS, NRAS and BRAF mutations, ALK gene rearrangements and MET amplification. EGFR and KRAS mutation testing was evaluated using real time polymerase chain reaction (RT-PCR cobas®), BRAF and NRAS mutations using multiplex PCR and capillary electrophoresis-single strand conformation analysis, and ALK and MET aberrations with fluorescent in situ hybridization. All genetic aberrations detected were validated independently.
Results: A total of 105 patients diagnosed with SCLC between July 1990 and September 2006 were included. 60 (57 %) patients had suitable tumour tissue for molecular testing. 25 patients were successfully evaluated for all six pre-defined molecular aberrations. Eleven patients failed all molecular analysis. No mutations in EGFR, KRAS and NRAS were detected, and no ALK gene rearrangements or MET gene amplifications were identified. A V600E substitution in BRAF was detected in a Caucasian male smoker diagnosed with SCLC with squamoid and glandular features.
Conclusion: The paucity of patients with sufficient tumour tissue, quality of DNA extracted and low frequency of aberrations detected indicate that alternative molecular characterisation approaches are necessary, such as the use of circulating plasma DNA in patients with SCLC.
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Amphibian defensive skin secretions remain a largely untapped resource for the peptide biochemist with an interest in the identification, structural characterization, and precursor cDNA cloning of novel bioactive peptides. Here we report the isolation, structural characterization, functional profiling, and nucleotide sequence of precursor cDNA of a novel histamine-releasing heptadecapeptide, FIPVTLLALHKIKEKLN-amide, from the defensive skin secretion of the African running frog, Kassina senegalensis. This peptide was found to be a potent histamine secretagogue (EC[5][0]=6 µM; maximal release = 25 µM) in a rat peritoneal mast cell model system and was accordingly named kassinakinin S. The open-reading frame of the cDNA encoding prepro-kassinakinin S was found to consist of 71 amino acid residues containing a single copy of kassinakinin S and its glycyl residue amide donor at the C-terminus. Kassinakinin S can thus be added to the growing list of amphibian skin bioactive peptide prototypes.
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In this study, we report on a novel, expedited solid-phase approach for the synthesis of biotinylated and fluorescently tagged irreversible affinity based probes for the chymotrypsin and elastase-like serine proteases. The novel solid-phase biotinylation or fluorescent labeling of the aminoalkane diphenyl phosphonate warhead using commercially available Biotin-PEG-NovaTag or EDANS NovaTag resin permits rapid, facile synthesis of these reagents. We demonstrate the kinetic evaluation and utilization of a number of these irreversible inactivators for chymotrypsin-like (chymotrypsin/human cathepsin G) and elastase-like serine proteases. Encouragingly, these compounds display comparable potency against their target proteases as their N-benzyloxycarbonyl (Cbz)-protected parent compounds, from which they were derived, and function as efficient active site-directed inactivators of their target proteases. We subsequently applied the biotinylated reagents for the sensitive detection of protease species via Western blot, showing that the inactivation of the protease was specifically mediated through the active site serine. Furthermore, we also demonstrate the successful detection of serine protease species with the fluorescently labeled derivatives “in-gel”, thus avoiding the need for downstream Western blotting. Finally, we also show the utility of biotinylated and pegylated affinity probes for the isolation/enrichment of serine protease species, via capture with immobilized streptavidin, and their subsequent identification via de novo sequencing. Given their selectivity of action against the serine proteases, we believe that these reagents can be exploited for the direct, rapid, and selective identification of these enzymes from biological milieu containing multiple protease subclasses.
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Epidemiological studies show that some children develop wheezing after 3 yr of age which tends to persist. It is unknown how this starts or whether there is a period of asymptomatic inflammation. The aim of this study is to determine whether lower airway allergic inflammation pre-exists in late onset childhood wheeze (LOCW). Follow-up study of children below 5 yr who had a non-bronchoscopic bronchoalveolar lavage (BAL) performed during elective surgery. The children had acted as normal controls. A modified ISAAC questionnaire was sent out at least 7 yr following the initial BAL, and this was used to ascertain whether any children had subsequently developed wheezing or other atopic disease (eczema, allergic rhinitis). Cellular and cytokine data from the original BAL were compared between those who never wheezed (NW) and those who had developed LOCW. Eighty-one normal non-asthmatic children were recruited with a median age of 3.2 . Of the 65 children contactable, 9 (16.7%) had developed wheeze, 11 (18.5%) developed eczema and 14 (22.2%) developed hay fever. In five patients, wheeze symptoms developed mean 3.3- yr (range: 2–5 yr) post-BAL. Serum IgE and blood eosinophils were not different in the LOCW and NW, although the blood white cell count was lower in the LOCW group. The median BAL eosinophil % was significantly increased in the patients with LOCW (1.55%, IQR: 0.33 to 3.92) compared to the children who never wheezed, NW (0.1, IQR: 0.0 to 0.3, p = 0.01). No differences were detected for other cell types. There are no significant differences in BAL cytokine concentrations between children with LOCW and NW children. Before late onset childhood wheezing developed, we found evidence of elevated eosinophils in the airways. These data suggest pre-existent airways inflammation in childhood asthma some years before clinical presentation.
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Racemic (1R*,2R*)-1,2-dihydroxy-[1- 13C 1]propylphosphonic acid and 1-hydroxy-[1- 13C 1]acetone were synthesized and fed to R. huakuii PMY1. Alanine and a mixture of valine and methionine were isolated as their N-acetyl derivatives from the cell hydrolysate by reversed-phase HPLC and analyzed by NMR spectroscopy. It was found that the carbon atoms of the respective carboxyl groups were highly 13C-labeled (up to 65 %). Hydroxyacetone is therefore considered an obligatory intermediate of the biodegradation of fosfomycin by R. huakuii PMY1.
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The authors consider a point percolation lattice representation of a large-scale wireless relay sensor network (WRSN) deployed in a cluttered environment. Each relay sensor corresponds to a grid point in the random lattice and the signal sent by the source is modelled as an ensemble of photons that spread in the space, which may 'hit' other sensors and are 'scattered' around. At each hit, the relay node forwards the received signal to its nearest neighbour through direction-selective relaying. The authors first derive the distribution that a relay path reaches a prescribed location after undergoing certain number of hops. Subsequently, a closed-form expression of the average received signal strength (RSS) at the destination can be computed as the summation of all signal echoes' energy. Finally, the effect of the anomalous diffusion exponent ß on the mean RSS in a WRSN is studied, for which it is found that the RSS scaling exponent e is given by (3ß-1)/ß. The results would provide useful insight into the design and deployment of large-scale WRSNs in future. © 2011 The Institution of Engineering and Technology.
Resumo:
Neuropeptides are ubiquitous intercellular signalling molecules in all Metazoa with nervous systems. Research over the past 10 years has confirmed through immunocytochemistry that neuropeptides are widespread and abundant in the nervous systems of helminth parasites. Biochemical isolation and characterisation studies have indentified the primary structures of numerous structurally-related peptides in helminths, the best studied being the FMRFamide-related peptides (FaRPs). While to date only four FaRPs have been identified from platyhelminths, some 60 FaRPs or FaRP-like peptides have been isolated or predicted for nematodes. Preliminary physiological studies have shown that FaRPs are strongly myoactive, but with quire different actions in the two groups of helminth parasite. The absence of FaRPs from vertebrates suggests compounds with a high affinity for FaRP receptors are likely to have selective effects against helminths and, if protected from degradation, could have therapeutic potential.
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This article reports an initiative to improve students' insight into service user and carer experience of endoscopy, particularly those with severe disability, such as spinal cord injury. This insight has the potential to improve the information provided and level of person-centred care in an endoscopy service. It was evident in the feedback from the classroom encounter that the teaching and learning strategy had a positive outcome, which will allow us to integrate the approach into future curriculum development and delivery, bringing the lived experience from the service user and carer perspective into the classroom. Students engaged in discussion and used their reflective skills to develop sensitivity to those with physical disability and complex needs requiring endoscopy procedures.
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Eight Creative Classroom (CCR) elements are used as a framework for analysing teachers’ current attitudes towards the use of moving images as a tool for teaching digital literacy to pupils aged 11-18 years in the context of ‘Creative Classrooms’. This paper reports on the challenges being faced by innovative teachers willing to adopt moving image (as a new ICT) into their teaching, and highlights the gaps currently present in the systemic support structures in schools which need to be addressed for innovative pedagogical practices to occur in these Creative Classrooms. By ensuring educators learn from their experiences of poor ICT uptake in the past and utilise these lessons for future innovations in classrooms, it is hoped that the transition to moving image, and its associated digital literacy skills, will be smooth and beneficial to the learners.
Resumo:
Preparing social work students for the demands of changing social environments and to promote student mobility and interest in overseas employment opportunities have resulted in an increasing demand for international social work placements. The literature describes numerous examples of social work programmes that offer a wide variety of international placements. However, research about the actual benefit of undertaking an overseas placement is scant with limited empirical evidence on the profile of students participating, their experience of the tasks offered, the supervisory practice and the outcomes for students' professional learning and career. This study contributes to the existing body of literature by exploring the relevance of international field placements for students and is unique in that it draws its sample from students who have graduated so provides a distinctive perspective in which to compare their international placement with their other placement/s as well as evaluating what were the benefits and drawbacks for them in terms of their careers, employment opportunities and current professional practice.