28 resultados para no duplication


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Cathepsin L proteases secreted by the helminth pathogen Fasciola hepatica have functions in parasite virulence including tissue invasion and suppression of host immune responses. Using proteomics methods alongside phylogenetic studies we characterized the profile of cathepsin L proteases secreted by adult F. hepatica and hence identified those involved in host-pathogen interaction. Phylogenetic analyses showed that the Fasciola cathepsin L gene family expanded by a series of gene duplications followed by divergence that gave rise to three clades associated with mature adult worms (Clades 1, 2, and 5) and two clades specific to infective juvenile stages (Clades 3 and 4). Consistent with these observations our proteomics studies identified representatives from Clades 1, 2, and 5 but not from Clades 3 and 4 in adult F. hepatica secretory products. Clades 1 and 2 account for 67.39 and 27.63% of total secreted cathepsin Ls, respectively, suggesting that their expansion was positively driven and that these proteases are most critical for parasite survival and adaptation. Sequence comparison studies revealed that the expansion of cathepsin Ls by gene duplication was followed by residue changes in the S2 pocket of the active site. Our biochemical studies showed that these changes result in alterations in substrate binding and suggested that the divergence of the cathepsin L family produced a repertoire of enzymes with overlapping and complementary substrate specificities that could cleave host macromolecules more efficiently. Although the cathepsin Ls are produced as zymogens containing a prosegment and mature domain, all secreted enzymes identified by MS were processed to mature active enzymes. The prosegment region was highly conserved between the clades except at the boundary of prosegment and mature enzyme. Despite the lack of conservation at this section, sites for exogenous cleavage by asparaginyl endopeptidases and a Leu-Ser[downward arrow]His motif for autocatalytic cleavage by cathepsin Ls were preserved.

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The excretory-secretory (ES) proteins of nematode parasites are of major interest as they function at the host-parasite interface and are likely to have roles crucial for successful parasitism. Furthermore, the ES proteins of intracellular nematodes such as Trichinella spiralis may also function to regulate gene expression in the host cell. In a recent proteomic analysis we identified a novel secreted cystatin-like protein from T. spiralis L1 muscle larva. Here we show that the protein, MCD-1 (multi-cystatin-like domain protein 1), contains three repeating cystatin-like domains and analysis of the mcd-1 gene structure suggests that the repeated domains arose from duplication of an ancestral cystatin gene. Cystatins are a diverse group of cysteine protease inhibitors and those secreted by parasitic nematodes are important immuno-modulatory factors. The cystatin superfamily also includes cystatin-like proteins that have no cysteine protease inhibitory activity. A recombinant MCD-1 protein expressed as a GST-fusion protein in Escherichia coli failed to inhibit papain in vitro suggesting that the T. spiralis protein is a new member of the non-inhibitory cystatin-related proteins. MCD-1 secreted from T. spiralis exists as high- and low-molecular weight isoforms and we show that a recombinant MCD-1 protein secreted by HeLa cells undergoes pH-dependent processing that may result in the release of individual cystatin-like domains. Furthermore, we found that mcd-1 gene expression is largely restricted to intracellular stages with the highest levels of expression in the adult worms. It is likely that the major role of the protein is during the intestinal stage of T. spiralis infections.

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BACKGROUND: Overuse of unnecessary medications in frail older adults with limited life expectancy remains an understudied challenge. OBJECTIVE: To identify intervention studies that reduced use of unnecessary medications in frail older adults. A secondary goal was to identify and review studies focusing on patients approaching end of life. We examined criteria for identifying unnecessary medications, intervention processes for medication reduction, and intervention effectiveness. METHODS: A systematic review of English articles using MEDLINE, EMBASE, and International Pharmaceutical Abstracts from January 1966 to September 2012. Additional studies were identified by searching bibliographies. Search terms included prescription drugs, drug utilization, hospice or palliative care, and appropriate or inappropriate. A manual review of 971 identified abstracts for the inclusion criteria (study included an intervention to reduce chronic medication use; at least 5 participants; population included patients aged at least 65 years, hospice enrollment, or indication of frailty or risk of functional decline-including assisted living or nursing home residence, inpatient hospitalization) yielded 60 articles for full review by 3 investigators. After exclusion of review articles, interventions targeting acute medications, or studies exclusively in the intensive care unit, 36 articles were retained (including 13 identified by bibliography review). Articles were extracted for study design, study setting, intervention description, criteria for identifying unnecessary medication use, and intervention outcomes. RESULTS: The studies included 15 randomized controlled trials, 4 non-randomized trials, 6 pre-post studies, and 11 case series. Control groups were used in over half of the studies (n = 20). Study populations varied and included residents of nursing homes and assisted living facilities (n = 16), hospitalized patients (n = 14), hospice/palliative care patients (n = 3), home care patients (n = 2), and frail or disabled community-dwelling patients (n = 1). The majority of studies (n = 21) used implicit criteria to identify unnecessary medications (including drugs without indication, unnecessary duplication, and lack of effectiveness); only one study incorporated patient preference into prescribing criteria. Most (25) interventions were led by or involved pharmacists, 4 used academic detailing, 2 used audit and feedback reports targeting prescribers, and 5 involved physician-led medication reviews. Overall intervention effect sizes could not be determined due to heterogeneity of study designs, samples, and measures. CONCLUSIONS: Very little rigorous research has been conducted on reducing unnecessary medications in frail older adults or patients approaching end of life.

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BACKGROUND: Measures that reflect patients' assessment of their health are of increasing importance as outcome measures in randomised controlled trials. The methodological approach used in the pre-validation development of new instruments (item generation, item reduction and question formatting) should be robust and transparent. The totality of the content of existing PRO instruments for a specific condition provides a valuable resource (pool of items) that can be utilised to develop new instruments. Such 'top down' approaches are common, but the explicit pre-validation methods are often poorly reported. This paper presents a systematic and generalisable 5-step pre-validation PRO instrument methodology.

METHODS: The method is illustrated using the example of the Aberdeen Glaucoma Questionnaire (AGQ). The five steps are: 1) Generation of a pool of items; 2) Item de-duplication (three phases); 3) Item reduction (two phases); 4) Assessment of the remaining items' content coverage against a pre-existing theoretical framework appropriate to the objectives of the instrument and the target population (e.g. ICF); and 5) qualitative exploration of the target populations' views of the new instrument and the items it contains.

RESULTS: The AGQ 'item pool' contained 725 items. Three de-duplication phases resulted in reduction of 91, 225 and 48 items respectively. The item reduction phases discarded 70 items and 208 items respectively. The draft AGQ contained 83 items with good content coverage. The qualitative exploration ('think aloud' study) resulted in removal of a further 15 items and refinement to the wording of others. The resultant draft AGQ contained 68 items.

CONCLUSIONS: This study presents a novel methodology for developing a PRO instrument, based on three sources: literature reporting what is important to patient; theoretically coherent framework; and patients' experience of completing the instrument. By systematically accounting for all items dropped after the item generation phase, our method ensures that the AGQ is developed in a transparent, replicable manner and is fit for validation. We recommend this method to enhance the likelihood that new PRO instruments will be appropriate to the research context in which they are used, acceptable to research participants and likely to generate valid data.

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Epidemiological and genetic data support the notion that schizophrenia and bipolar disorder share genetic risk factors. In our previous genome-wide association (GWA) study, meta-analysis and follow-up (totaling as many as 18,206 cases and 42,536 controls), we identified four loci showing genome-wide significant association with schizophrenia. Here we consider a mixed schizophrenia and bipolar disorder (psychosis) phenotype (addition of 7,469 bipolar disorder cases, 1,535 schizophrenia cases, 333 other psychosis cases, 808 unaffected family members and 46,160 controls). Combined analysis reveals a novel variant at 16p11.2 showing genome-wide significant association (rs4583255[T], OR = 1.08, P = 6.6 × 10−11). The new variant is located within a 593 kb region that substantially increases risk of psychosis when duplicated. In line with the association of the duplication with reduced body mass index (BMI), rs4583255[T] is also associated with lower BMI (P = 0.0039 in the public GIANT consortium dataset; P = 0.00047 in 22,651 additional Icelanders).

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Summary: Genome duplications and polyploidization events are thought to have played relevant roles in the early stages of vertebrate evolution, in particular near the time of divergence of the lamprey lineage. Additional genome duplications, specifically in ray-finned fish, may have occurred before the divergence of the teleosts. The role of polyploidization in vertebrate genome evolution is a thriving area of research. Sturgeons (order Acipenseriformes) provide a unique model for the investigation of genome duplication, with existing species possessing 120, 250 or 360 chromosomes. In the present study, data from 240 sturgeon specimens representing 11 species were used for analysis of ploidy levels. Allele numbers were assessed at eleven microsatellite loci. The results provide further evidence for functional diploidy, tetraploidy and hexaploidy in species possessing 120, 250 and 360 chromosomes, respectively. The analysis also uncovered novel evidence for functional hexaploidy in the shortnose sturgeon (Acipenser brevirostrum). In conclusion, the process of functional genome reduction is demonstrated to be an on-going process in this fish lineage. © 2013 Blackwell Verlag GmbH.

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Background: Potentially inappropriate prescribing (PIP) in older people is associated with increases in morbidity, hospitalisation and mortality. The objective of this study was to estimate the prevalence of and factors associated with PIP, among those aged ≥70 years, in the United Kingdom, using a comprehensive set of prescribing indicators and comparing these to estimates obtained from a truncated set of the same indicators.

Methods: A retrospective cross-sectional study was carried out in the UK Clinical Practice Research Datalink (CPRD), in 2007. Participants included those aged ≥ 70 years, in CPRD. Fifty-two PIP indicators from the Screening Tool of Older Persons Potentially Inappropriate Prescriptions (STOPP) criteria were applied to data on prescribed drugs and clinical diagnoses. Overall prevalence of PIP and prevalence according to individual STOPP criteria were estimated. The relationship between PIP and polypharmacy (≥4 medications), comorbidity, age, and gender was examined. A truncated, subset of 28 STOPP criteria that were used in two previous studies, were further applied to the data to facilitate comparison.

Results: Using 52 indicators, the overall prevalence of PIP in the study population (n = 1,019,491) was 29%. The most common examples of PIP were therapeutic duplication (11.9%), followed by use of aspirin with no indication (11.3%) and inappropriate use of proton pump inhibitors (PPIs) (3.7%). PIP was strongly associated with polypharmacy (Odds Ratio 18.2, 95% Confidence Intervals, 18.0-18.4, P < 0.05). PIP was more common in those aged 70–74 years vs. 85 years or more and in males. Application of the smaller subset of the STOPP criteria resulted in a lower PIP prevalence at 14.9% (95% CIs 14.8-14.9%) (n = 151,598). The most common PIP issues identified with this subset were use of PPIs at maximum dose for > 8 weeks, NSAIDs for > 3 months, and use of long-term neuroleptics.

Conclusions: PIP was prevalent in the UK and increased with polypharmacy. Application of the comprehensive set of STOPP criteria allowed more accurate estimation of PIP compared to the subset of criteria used in previous studies. These findings may provide a focus for targeted interventions to reduce PIP.

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The global financial crisis has forced governments across the globe to seek new ways of achieving efficiencies and savings in running their state administrations. Prominent amongst the variety of approaches adopted is the concept of shared services, which purports to offer a means of consolidating common tasks, reducing duplication, and achieving greater value for money. Based on successful experiences in the private sector, the phenomenon of shared service centres (SSCs) as a new co-ordination practice is of particular interest. In this chapter, the use of shared services and SSCs in Ireland is considered.

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Protocols of systematic reviews and meta-analyses allow for planning and documentation of review methods, act as a guard against arbitrary decision making during review conduct, enable readers to assess for the presence of selective reporting against completed reviews, and, when made publicly available, reduce duplication of efforts and potentially prompt collaboration. Evidence documenting the existence of selective reporting and excessive duplication of reviews on the same or similar topics is accumulating and many calls have been made in support of the documentation and public availability of review protocols. Several efforts have emerged in recent years to rectify these problems, including development of an international register for prospective reviews (PROSPERO) and launch of the first open access journal dedicated to the exclusive publication of systematic review products, including protocols (BioMed Central's Systematic Reviews). Furthering these efforts and building on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines, an international group of experts has created a guideline to improve the transparency, accuracy, completeness, and frequency of documented systematic review and meta-analysis protocols--PRISMA-P (for protocols) 2015. The PRISMA-P checklist contains 17 items considered to be essential and minimum components of a systematic review or meta-analysis protocol.This PRISMA-P 2015 Explanation and Elaboration paper provides readers with a full understanding of and evidence about the necessity of each item as well as a model example from an existing published protocol. This paper should be read together with the PRISMA-P 2015 statement. Systematic review authors and assessors are strongly encouraged to make use of PRISMA-P when drafting and appraising review protocols.

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Realising memory intensive applications such as image and video processing on FPGA requires creation of complex, multi-level memory hierarchies to achieve real-time performance; however commerical High Level Synthesis tools are unable to automatically derive such structures and hence are unable to meet the demanding bandwidth and capacity constraints of these applications. Current approaches to solving this problem can only derive either single-level memory structures or very deep, highly inefficient hierarchies, leading in either case to one or more of high implementation cost and low performance. This paper presents an enhancement to an existing MC-HLS synthesis approach which solves this problem; it exploits and eliminates data duplication at multiple levels levels of the generated hierarchy, leading to a reduction in the number of levels and ultimately higher performance, lower cost implementations. When applied to synthesis of C-based Motion Estimation, Matrix Multiplication and Sobel Edge Detection applications, this enables reductions in Block RAM and Look Up Table (LUT) cost of up to 25%, whilst simultaneously increasing throughput.

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FMRFamide-like peptide (FLP) signalling systems are core to nematode neuromuscular function. Novel drug discovery efforts associated with nematode FLP/FLP receptor biology are advanced through the accumulation of basic biological data that can reveal subtle complexities within the neuropeptidergic system. This study reports the characterisation of FMRFamide-like peptide encoding gene-11 (flp-11) and FMRFamide-like peptide encoding gene-32 (flp-32), two distinct flp genes which encode the analogous peptide, AMRN(A/S)LVRFamide, in multiple nematode species - the only known example of this phenomenon within the FLPergic system of nematodes. Using bioinformatics, in situ hybridisation, immunocytochemistry and behavioural assays we show that: (i) flp-11 and -32 are distinct flp genes expressed individually or in tandem across multiple nematode species, where they encode a highly similar peptide; (ii) flp-11 does not appear to be the most widely expressed flp in Caenorhabditis elegans; (iii) in species expressing both flp-11 and flp-32, flp-11 displays a conserved, restricted expression pattern across nematode clades and lifestyles; (iv) in species expressing both flp-11 and flp-32, flp-32 expression is more widespread and less conserved than flp-11; (v) in species expressing only flp-11, the flp-11 expression profile is more similar to the flp-32 profile observed in species expressing both; and (vi) FLP-11 peptides inhibit motor function in multiple nematode species. The biological significance and evolutionary origin of flp-11 and -32 peptide duplication remains unclear despite attempts to identify a common ancestor; this may become clearer as the availability of genomic data improves. This work provides insight into the complexity of the neuropeptidergic system in nematodes, and begins to examine how nematodes may compensate for structural neuronal simplicity. From a parasite control standpoint this work underscores the importance of basic biological data, and has wider implications for the utility of C. elegans as a model for parasite neurobiology.

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Acquired resistance to selective FLT3 inhibitors is an emerging clinical problem in the treatment of FLT3-ITD(+) acute myeloid leukaemia (AML). The paucity of valid pre-clinical models has restricted investigations to determine the mechanism of acquired therapeutic resistance, thereby limiting the development of effective treatments. We generated selective FLT3 inhibitor-resistant cells by treating the FLT3-ITD(+) human AML cell line MOLM-13 in vitro with the FLT3-selective inhibitor MLN518, and validated the resistant phenotype in vivo and in vitro. The resistant cells, MOLM-13-RES, harboured a new D835Y tyrosine kinase domain (TKD) mutation on the FLT3-ITD(+) allele. Acquired TKD mutations, including D835Y, have recently been identified in FLT3-ITD(+) patients relapsing after treatment with the novel FLT3 inhibitor, AC220. Consistent with this clinical pattern of resistance, MOLM-13-RES cells displayed high relative resistance to AC220 and Sorafenib. Furthermore, treatment of MOLM-13-RES cells with AC220 lead to loss of the FLT3 wild-type allele and the duplication of the FLT3-ITD-D835Y allele. Our FLT3-Aurora kinase inhibitor, CCT137690, successfully inhibited growth of FLT3-ITD-D835Y cells in vitro and in vivo, suggesting that dual FLT3-Aurora inhibition may overcome selective FLT3 inhibitor resistance, in part due to inhibition of Aurora kinase, and may benefit patients with FLT3-mutated AML.

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The efficacy of tyrosine kinase (TK) inhibitors on non-cycling acute myeloid leukaemia (AML) cells, previously shown to have potent tumourigenic potential, is unknown. This pilot study describes the first attempt to characterize non-cycling cells from a small series of human FMS-like tyrosine kinase 3 (FLT3) mutation positive samples. CD34+ AML cells from patients with FLT3 mutation positive AML were cultured on murine stroma. In expansion cultures, non-cycling cells were found to retain CD34+ expression in contrast to dividing cells. Leukaemic gene rearrangements could be detected in non-cycling cells, indicating their leukaemic origin. Significantly, the FLT3-internal tandem duplication (ITD) mutation was found in the non-cycling fraction of four out of five cases. Exposure to the FLT3-directed inhibitor TKI258 clearly inhibited the growth of AML CD34+ cells in short-term cultures and colony-forming unit assays. Crucially, non-cycling cells were not eradicated, with the exception of one case, which exhibited exquisite sensitivity to the compound. Moreover, in longer-term cultures, TKI258-treated non-cycling cells showed no growth impairment compared to treatment-naive non-cycling cells. These findings suggest that non-cycling cells in AML may constitute a disease reservoir that is resistant to TK inhibition. Further studies with a larger sample size and other inhibitors are warranted.