712 research outputs found

    A randomised trial of adaptive pacing therapy, cognitive behaviour therapy, graded exercise, and specialist medical care for chronic fatigue syndrome (PACE): statistical analysis plan

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    BACKGROUND: The publication of protocols by medical journals is increasingly becoming an accepted means for promoting good quality research and maximising transparency. Recently, Finfer and Bellomo have suggested the publication of statistical analysis plans (SAPs).The aim of this paper is to make public and to report in detail the planned analyses that were approved by the Trial Steering Committee in May 2010 for the principal papers of the PACE (Pacing, graded Activity, and Cognitive behaviour therapy: a randomised Evaluation) trial, a treatment trial for chronic fatigue syndrome. It illustrates planned analyses of a complex intervention trial that allows for the impact of clustering by care providers, where multiple care-providers are present for each patient in some but not all arms of the trial. RESULTS: The trial design, objectives and data collection are reported. Considerations relating to blinding, samples, adherence to the protocol, stratification, centre and other clustering effects, missing data, multiplicity and compliance are described. Descriptive, interim and final analyses of the primary and secondary outcomes are then outlined. CONCLUSIONS: This SAP maximises transparency, providing a record of all planned analyses, and it may be a resource for those who are developing SAPs, acting as an illustrative example for teaching and methodological research. It is not the sum of the statistical analysis sections of the principal papers, being completed well before individual papers were drafted. TRIAL REGISTRATION: ISRCTN54285094 assigned 22 May 2003; First participant was randomised on 18 March 2005

    Using Scenarios to Validate Requirements through the use of Eye-Tracking in Prototyping

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    Research has shown that eliciting and capturing the correct behavior of systems reduces the number of defects that a system contains. A requirements engineer will model the functions of the system to gain a comprehensive understanding of the system in question. Engineers must verify the model for correctness by either having another engineer review it or build a prototype and validate with a stakeholder. However, research has shown that this form of verification can be ineffective because looking at an existing model can be suggestive and stump the development of new ideas. This paper provides an automated technique that can be used as an unbiased review of use case scenarios. Using the prototype and a scenario, a stakeholder can be guided through the use case scenario demonstrating where they expect to find the next step while their eye movements are tracked. Analysis of the eye tracking data can be used to identify missing requirements such as interaction steps that should have alternative sequences or determining problems with the flow of actions

    Percutaneous coronary intervention and in-hospital outcomes in patients with leukemia: a nationwide analysis

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    Objectives: To examine the association between current leukemia diagnosis and in-hospital clinical outcomes in patients undergoing percutaneous coronary intervention (PCI) in the US. Background: Leukemia is most common hematological malignancy and is associated with an increased risk of thrombotic and bleeding complications in patients undergoing PCI. There are limited data around clinical outcomes of leukemia patients undergoing PCI. Methods: We used the National Inpatient Sample (NIS) to investigate the outcomes of leukemia patients undergoing PCI between 2004 and 2014. Patients were then subdivided into diagnoses of acute or chronic myeloid leukemia (AML or CML) and acute or chronic lymphoid leukemia (ALL, CLL). Multiple logistic regressions were used to study the association of a leukemia diagnosis with in-hospital outcomes; mortality, bleeding, vascular and cardiac complications, and stroke. Results: There were 6,561,445 records of patients who underwent PCI during the study time, of which 15,789 patients had a diagnosis of leukemia. The most common leukemia subtype was CLL accounting for 75% of the cohort (n=10,800). After multivariable adjustment, a leukemia diagnosis was associated with significantly increased odds of in-hospital mortality (OR 1.41 (95% CI (1.11-1.79)) and bleeding (OR 1.87 (95% CI 1.56-2.09)), whereas patients with AML had a 5-fold increase of in-hospital mortality (OR 5.38 (95% CI 2.94-9.76)). Conclusion: Patients with current diagnosis of leukemia are at increased risk of procedurerelated complications following PCI. A multi-disciplinary approach is needed amongst interventional cardiologists, oncologists and hematologists to minimize procedural complications and improve outcomes in this high-risk cohort

    Demographic parameters of reintroduced grey partridges in central Italy and the effect of weather

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    International audienceGrey partridge populations declined in Europe from mid-1950s onwards mostly due to modifications of agricultural cropping. In Italy, the decline was even more dramatic because of over-hunting and restocking with allochthonous birds. We carried out a research on a re-introduced population in Central Italy from 1995 to 2005, with the aim of evaluating the reintroduction success and separating the intrinsic and external factors influencing year-to-year changes in partridge density with particular respect to the weather. Average spring density was 4.5 pairs per square kilometre (SD = 1.52); our population reached a peak few years after the reintroduction and then declined. Brood production rate was close to that of declining European populations (average 33.9%; SD = 10.21), and chick survival rate (average 40%; = 17.61) determined the change of breeding abundance from year to year + 1. Our population seemed to be mainly affected by brood production and chick survival rates and by the weather; in particular, higher early winter and spring temperatures increased breeding density whilst higher early summer temperatures decreased brood production rate

    XIAP impairs Smac release from the mitochondria during apoptosis

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    X-linked inhibitor of apoptosis protein (XIAP) is a potent inhibitor of caspases 3, 7 and 9, and mitochondrial Smac (second mitochondria-derived activator of caspase) release during apoptosis inhibits the activity of XIAP. In this study we show that cytosolic XIAP also feeds back to mitochondria to impair Smac release. We constructed a fluorescent XIAP-fusion protein by labelling NH2- and COOH-termini with Cerulean fluorescent protein (C-XIAP-C). Immunoprecipitation confirmed that C-XIAP-C retained the ability to interact with Smac and impaired extrinsically and intrinsically activated apoptosis in response to tumour necrosis factor-related apoptosis-inducing ligand/cycloheximide and staurosporine. In C-XIAP-C-expressing cells, cytochrome c release from mitochondria proceeded normally, whereas Smac release was significantly prolonged and incomplete. In addition, physiological expression of native XIAP prolonged or limited Smac release in HCT-116 colon cancer cells and primary mouse cortical neurons. The Smac-binding capacity of XIAP, but not caspase inhibition, was central for mitochondrial Smac retention, as evidenced in experiments using XIAP mutants that cannot bind to Smac or effector caspases. Similarly, the release of a Smac mutant that cannot bind to XIAP was not impaired by C-XIAP-C expression. Full Smac release could however be provoked by rapid cytosolic C-XIAP-C depletion upon digitonin-induced plasma membrane permeabilization. Our findings suggest that although mitochondria may already contain pores sufficient for cytochrome c release, elevated amounts of XIAP can selectively impair and limit the release of Smac

    Anthropogenically-mediated density dependence in a declining farmland bird

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    Land management intrinsically influences the distribution of animals and can consequently alter the potential for density-dependent processes to act within populations. For declining species, high densities of breeding territories are typically considered to represent productive populations. However, as density-dependent effects of food limitation or predator pressure may occur (especially when species are dependent upon separate nesting and foraging habitats), high territory density may limit per-capita productivity. Here, we use a declining but widespread European farmland bird, the yellowhammer Emberiza citrinella L., as a model system to test whether higher territory densities result in lower fledging success, parental provisioning rates or nestling growth rates compared to lower densities. Organic landscapes held higher territory densities, but nests on organic farms fledged fewer nestlings, translating to a 5 times higher rate of population shrinkage on organic farms compared to conventional. In addition, when parental provisioning behaviour was not restricted by predation risk (i.e. at times of low corvid activity), nestling provisioning rates were higher at lower territory densities, resulting in a much greater increase in nestling mass in low density areas, suggesting that food limitation occurred at high densities. These findings in turn suggest an ecological trap, whereby preferred nesting habitat does not provide sufficient food for rearing nestlings at high population density, creating a population sink. Habitat management for farmland birds should focus not simply on creating a high nesting density, but also on ensuring heterogeneous habitats to provide food resources in close proximity to nesting birds, even if this occurs through potentially restricting overall nest density but increasing population-level breeding success

    Skeletal Muscle Differentiation Evokes Endogenous XIAP to Restrict the Apoptotic Pathway

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    Myotube apoptosis occurs normally during muscle development and aging but it can lead to destruction of skeletal muscle in neuromuscular diseases. Therefore, understanding how myotube apoptosis is regulated is important for developing novel strategies for treatment of muscle loss. We investigated the regulation of apoptosis in skeletal muscle and report a striking increase in resistance to apoptosis following differentiation. We find mitotic C2C12 cells (myoblast-like cells) are sensitive to cytosolic cytochrome c microinjection. However, differentiated C2C12 cells (myotube-like cells) and primary myotubes are markedly resistant. This resistance is due to endogenous X-linked inhibitor of apoptotic protein (XIAP). Importantly, the selective difference in the ability of XIAP to block myotube but not myoblast apoptosis is not due to a change in XIAP but rather a decrease in Apaf-1 expression. This decrease in Apaf-1 links XIAP to caspase activation and death. Our findings suggest that in order for myotubes to die, they may degrade XIAP, functionally inactivate XIAP or upregulate Apaf-1. Importantly, we identify a role for endogenous Smac in overcoming XIAP to allow myotube death. However, in postmitotic cardiomyocytes, where XIAP also restricts apoptosis, endogenous Smac was not capable of overcoming XIAP to cause death. These results show that as skeletal muscle differentiate, they become resistant to apoptosis because of the ability of XIAP to regulate caspase activation. The increased restriction of apoptosis in myotubes is presumably important to ensure the long term survival of these postmitotic cells as they play a vital role in the physiology of organisms

    Management Strategies and Clinical Outcomes of Acute Myocardial Infarction in Leukemia Patients: Insights from Nationwide United States Hospitalizations.

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    BACKGROUND: Patients with leukemia are at increased risk of cardiovascular events. There are limited outcomes data for patients with a history of leukemia who present with an acute myocardial infarction (AMI). METHODS: We queried the Nationwide Inpatient Sample (2004-2014) for patients with a primary discharge diagnosis of AMI, and a concomitant diagnosis of leukemia, and further stratified according to the subtype of leukemia. Multivariable logistic regression was conducted to identify the association between leukemia and major acute cardiovascular and cerebrovascular events (MACCE; composite of mortality, stroke and cardiac complications) and bleeding. RESULTS: Out of 6,750,878 AMI admissions, a total of 21,694 patients had a leukemia diagnosis. The leukemia group experienced higher rates of MACCE (11.8% vs. 7.8%), mortality (10.3% vs. 5.8%) and bleeding (5.6% vs. 5.3%). Following adjustments, leukemia was independently associated with increased odds of MACCE (OR 1.26[1.20,1.31]) and mortality (OR 1.43[1.37,1.50]) without an increased risk of bleeding (OR 0.86[0.81,0.92]). Acute myeloid leukemia (AML) was associated with approximately three-fold risk of MACCE (OR 2.81[2.51, 3.13]) and a four-fold risk of mortality (OR 3.75[3.34, 4.22]). Patients with leukemia were less likely to undergo coronary angiography (CA) (48.5% vs. 64.5%) and percutaneous coronary intervention (PCI) (28.2% vs. 42.9%) compared to those without leukemia. CONCLUSION: Patients with leukemia, especially those with AML, are associated with poor clinical outcomes after AMI, and are less likely to receive CA and PCI compared to those without leukemia. A multi-disciplinary approach between cardiologists and hematology oncologists may improve the outcomes of patients with leukemia after AMI
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