2,922 research outputs found

    Symptoms and patient factors associated with diagnostic intervals for pancreatic cancer (SYMPTOM pancreatic study): a prospective cohort study

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    This is the final version. Available on open access from Elsevier via the DOI in this recordBackground Pancreatic cancer is the tenth most common cancer in the UK; however, outcomes are poor, in part due to late diagnosis. We aimed to identify symptoms and other clinical and sociodemographic factors associated with pancreatic cancer diagnosis and diagnostic intervals. Methods We did this prospective cohort study at seven hospitals in two regions in England. We recruited participants aged 40 years or older who were referred for suspicion of pancreatic cancer. Data were collected by use of a patient questionnaire and primary care and hospital records. Descriptive and regression analyses were done to examine associations between symptoms and patient factors with the total diagnostic interval (time from onset of the first symptom to the date of diagnosis), comprising patient interval (time from first symptom to first presentation) and health system interval (time from first presentation to diagnosis). Findings We recruited 391 participants between Jan 1, 2011, and Dec 31, 2014 (24% response rate). 119 (30%) participants were diagnosed with pancreatic cancer (41 [34%] had metastatic disease), 47 (12%) with other cancers, and 225 (58%) with no cancer. 212 (54%) patients had multiple first symptoms whereas 161 (41%) patients had a solitary first symptom. In this referred population, no initial symptoms were reported more frequently by patients with cancer than by those with no cancer. Several subsequent symptoms predicted pancreatic cancer: jaundice (51 [49%] of 105 patients with pancreatic cancer vs 25 [12%] of 211 patients with no cancer; p<0·0001), fatigue (48/95 [51%] vs 40/155 [26%]; p=0·0001), change in bowel habit (36/87 [41%] vs 28/175 [16%]; p<0·0001), weight loss (55/100 [55%] vs 41/184 [22%]; p<0·0001), and decreased appetite (41/86 [48%] vs 41/156 [26%]; p=0·0011). There was no difference in any interval between patients with pancreatic cancer and those with no cancer (total diagnostic interval: median 117 days [IQR 57–234] vs 131 days [IQR 66–284]; p=0·32; patient interval 18 days [0–37] vs 15 days [1–62]; p=0·22; health system interval 76 days [28–161] vs 79 days [30–156]; p=0·68). Total diagnostic intervals were shorter when jaundice (hazard ratio [HR] 1·38, 95% CI 1·07–1·78; p=0·013) and decreased appetite (1·42, 1·11–1·82; p=0·0058) were reported as symptoms, and longer in patients presenting with indigestion (0·71, 0·56–0·89; p=0·0033), back pain (0·77, 0·59–0·99; p=0·040), diabetes (0·71, 0·52–0·97; p=0·029), and self-reported anxiety or depression, or both (0·67, 0·49–0·91; p=0·011). Health system intervals were likewise longer with indigestion (0·74, 0·58–0·95; p=0·0018), back pain (0·76, 0·58–0·99; p=0·044), diabetes (0·63, 0·45–0·89; p=0·0082), and self-reported anxiety or depression, or both (0·63, 0·46–0·88; p=0·0064), but were shorter with male sex (1·41, 1·1–1·81; p=0·0072) and decreased appetite (1·56, 1·19–2·06; p=0·0015). Weight loss was associated with longer patient intervals (HR 0·69, 95% CI 0·54–0·89; p=0·0047). Interpretation Although we identified no initial symptoms that differentiated people diagnosed with pancreatic cancer from those without pancreatic cancer, key additional symptoms might signal the disease. Health-care professionals should be vigilant to the possibility of pancreatic cancer in patients with evolving gastrointestinal and systemic symptoms, particularly in those with diabetes or mental health comorbidities. Funding National Institute for Health Research and Pancreatic Cancer Action.National Institute for Health Research (NIHR

    A comparison of missing data methods for hypothesis tests of the treatment effect in substance abuse clinical trials: a Monte-Carlo simulation study

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    <p>Abstract</p> <p>Background</p> <p>Missing data due to attrition are rampant in substance abuse clinical trials. However, missing data are often ignored in the presentation of substance abuse clinical trials. This paper demonstrates missing data methods which may be used for hypothesis testing.</p> <p>Methods</p> <p>Methods involving stratifying and weighting individuals based on missing data pattern are shown to produce tests that are robust to missing data mechanisms in terms of Type I error and power. In this article, we describe several methods of combining data that may be used for testing hypotheses of the treatment effect. Furthermore, illustrations of each test's Type I error and power under different missing data percentages and mechanisms are quantified using a Monte-Carlo simulation study.</p> <p>Results</p> <p>Type I error rates were similar for each method, while powers depended on missing data assumptions. Specifically, power was greatest for the weighted, compared to un-weighted methods, especially for greater missing data percentages.</p> <p>Conclusion</p> <p>Results of this study as well as extant literature demonstrate the need for standards of design and analysis specific to substance abuse clinical trials. Given the known substantial attrition rates and concern for the missing data mechanism in substance abuse clinical trials, investigators need to incorporate missing data methods a priori. That is, missing data methods should be specified at the outset of the study and not after the data have been collected.</p

    Dark Force Detection in Low Energy e-p Collisions

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    We study the prospects for detecting a light boson X with mass m_X < 100 MeV at a low energy electron-proton collider. We focus on the case where X dominantly decays to e+ e- as motivated by recent "dark force" models. In order to evade direct and indirect constraints, X must have small couplings to the standard model (alpha_X 10 MeV). By comparing the signal and background cross sections for the e- p e+ e- final state, we conclude that dark force detection requires an integrated luminosity of around 1 inverse attobarn, achievable with a forthcoming JLab proposal.Comment: 38 pages, 19 figures; v2, references adde

    Improved healing response in delayed unions of the tibia with low-intensity pulsed ultrasound: results of a randomized sham-controlled trial

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    <p>Abstract</p> <p>Background</p> <p>We compared the healing response of tibial delayed unions between subjects treated with low-intensity pulsed ultrasound (LIPUS) (n = 51) and subjects treated with a sham device (n = 50). Fracture age was ≥ 4 months in all cases. Study personnel and participants were blinded to random treatment assignment throughout the study.</p> <p>Methods</p> <p>This multi-center randomized sham-controlled trial was undertaken at six hospitals in Germany. Adult patients who had sustained a tibial shaft fracture that subsequently showed inadequate progress toward healing (i.e., delayed union) were enrolled and randomized to receive either LIPUS (Exogen 2000/2000+, Smith & Nephew GmbH, Schenefeld, Germany) or an identical nonoperative sham device. The daily treatment duration was 20 minutes, for a period of 16 weeks. Subjects randomly assigned to active treatment had the ultrasound pressure wave signal set at the following parameters: 1.5 MHz frequency, 1 kHz repetition rate, 200 μs pulse duration, 30 mW/cm<sup>2 </sup>spatial intensity. Progress toward healing was estimated from changes in bone mineral density (BMD) and gap area as determined from computed tomography scans. Intention-to-treat analysis was conducted using a multiple imputation methodology.</p> <p>Results</p> <p>Based on log-transformed data, mean improvement in BMD was 1.34 (90% confidence interval (CI) 1.14 to 1.57) times greater for LIPUS-treated subjects compared to sham (p = 0.002). A mean reduction in bone gap area also favored LIPUS treatment (p = 0.014).</p> <p>Conclusions</p> <p>These findings demonstrate significantly greater progress toward bone healing after LIPUS treatment compared to no LIPUS treatment in subjects with established delayed unions of the tibia.</p

    Speech and language therapy approaches to managing primary progressive aphasia

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    The term primary progressive aphasia (PPA) describes a group of neurodegenerative disorders with predominant speech and language dysfunction as their main feature. There are three main variants – the semantic variant, the nonfluent or agrammatic variant and the logopenic variant – each with specific linguistic deficits and different neuroanatomical involvement. There are currently no curative treatments or symptomatic pharmacological therapies. However, speech and language therapists have developed several impairment-based interventions and compensatory strategies for use in the clinic. Unfortunately, multiple barriers still need to be overcome to improve access to care for people with PPA, including increasing awareness among referring clinicians, improving training of speech and language therapists and developing evidence-based guidelines for therapeutic interventions. This review highlights this inequity and the reasons why neurologists should refer people with PPA to speech and language therapists

    The Heat Kernel on AdS_3 and its Applications

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    We derive the heat kernel for arbitrary tensor fields on S^3 and (Euclidean) AdS_3 using a group theoretic approach. We use these results to also obtain the heat kernel on certain quotients of these spaces. In particular, we give a simple, explicit expression for the one loop determinant for a field of arbitrary spin s in thermal AdS_3. We apply this to the calculation of the one loop partition function of N=1 supergravity on AdS_3. We find that the answer factorizes into left- and right-moving super Virasoro characters built on the SL(2, C) invariant vacuum, as argued by Maloney and Witten on general grounds.Comment: 46 pages, LaTeX, v2: Reference adde

    Infectious Disease Ontology

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    Technological developments have resulted in tremendous increases in the volume and diversity of the data and information that must be processed in the course of biomedical and clinical research and practice. Researchers are at the same time under ever greater pressure to share data and to take steps to ensure that data resources are interoperable. The use of ontologies to annotate data has proven successful in supporting these goals and in providing new possibilities for the automated processing of data and information. In this chapter, we describe different types of vocabulary resources and emphasize those features of formal ontologies that make them most useful for computational applications. We describe current uses of ontologies and discuss future goals for ontology-based computing, focusing on its use in the field of infectious diseases. We review the largest and most widely used vocabulary resources relevant to the study of infectious diseases and conclude with a description of the Infectious Disease Ontology (IDO) suite of interoperable ontology modules that together cover the entire infectious disease domain

    Mapping of hormones and cortisol responses in patients after Lyme neuroborreliosis

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    <p>Abstract</p> <p>Background</p> <p>Persistent symptoms after treatment for neuroborreliosis are common for reasons mainly unknown. These symptoms are often unspecific and could be caused by dysfunctions in endocrine systems, an issue that has not been previously addressed systematically. We therefore mapped hormone levels in patients with previous confirmed Lyme neuroborreliosis of different outcomes and compared them with a healthy control group.</p> <p>Methods</p> <p>Twenty patients of a retrospective cohort of patients treated for definite Lyme neuroborreliosis were recruited 2.3 to 3.7 years (median 2.7) after diagnosis, together with 23 healthy controls. Lyme neuroborreliosis patients were stratified into two groups according to a symptom/sign score. All participants underwent anthropometric and physiological investigation as well as an extensive biochemical endocrine investigation including a short high-dose adrenocorticotropic hormone stimulation (Synacthen<sup>®</sup>) test. In addition to hormonal status, we also examined electrolytes, 25-hydroxy-vitamin D and interleukin-6.</p> <p>Results</p> <p>Eight patients (40%) had pronounced symptoms 2-3 years after treatment. This group had a higher cortisol response to synacthen as compared with both controls and the Lyme neuroborreliosis patients without remaining symptoms (p < 0.001 for both comparisons). No other significant differences in the various baseline biochemical parameters, anthropometric or physiological data could be detected across groups.</p> <p>Conclusions</p> <p>Apart from a positive association between the occurrence of long-lasting complaints after Lyme neuroborreliosis and cortisol response to synacthen, no corticotropic insufficiency or other serious hormonal dysfunction was found to be associated with remaining symptoms after treatment for Lyme neuroborreliosis.</p
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