707 research outputs found

    Establishing, versus Maintaining, Brain Function: A Neuro-computational Model of Cortical Reorganization after Injury to the Immature Brain

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    The effect of age at injury on outcome after acquired brain injury (ABI) has been the subject of much debate. Many argue that young brains are relatively tolerant of injury. A contrasting viewpoint due to Hebb argues that greater system integrity may be required for the initial establishment of a function than for preservation of an already-established function. A neuro-computational model of cortical map formation was adapted to examine effects of focal and distributed injury at various stages of development. This neural network model requires a period of training during which it self-organizes to establish cortical maps. Injuries were simulated by lesioning the model at various stages of this process and network function was monitored as "development" progressed to completion. Lesion effects are greater for larger, earlier, and distributed (multifocal) lesions. The mature system is relatively robust, particularly to focal injury. Activities in recovering systems injured at an early stage show changes that emerge after an asymptomatic interval. Early injuries cause qualitative changes in system behavior that emerge after a delay during which the effects of the injury are latent. Functions that are incompletely established at the time of injury may be vulnerable particularly to multifocal injury

    Risk factors for high anti-HHV-8 antibody titers (≥1:51,200) in black, HIV-1 negative South African cancer patients: a case control study

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    Background: Infection with human herpesvirus 8 (HHV-8) is the necessary causal agent in the development of Kaposi's sarcoma (KS). Infection with HIV-1, male gender and older age all increase risk for KS. However, the geographic distribution of HHV-8 and KS both prior to the HIV/AIDS epidemic and with HIV/AIDS suggest the presence of an additional co-factor in the development of KS. Methods: Between January 1994 and October 1997, we interviewed 2576 black in-patients with cancer in Johannesburg and Soweto, South Africa. Blood was tested for antibodies against HIV-1 and HHV-8 and the study was restricted to 2191 HIV-1 negative patients. Antibodies against the latent nuclear antigen of HHV-8 encoded by orf73 were detected with an indirect immunofluorescence assay. We examined the relationship between high anti-HHV-8 antibody titers (≥1:51,200) and sociodemographic and behavioral factors using unconditional logistic regression models. Variables that were significant at p = 0.10 were included in multivariate analysis. Results: Of the 2191 HIV-1 negative patients who did not have Kaposi's sarcoma, 854 (39.0%) were positive for antibodies against HHV-8 according to the immunofluorescent assay. Among those seropositive for HHV-8, 530 (62.1%) had low titers (1:200), 227 (26.6%) had medium titers (1:51,200) and 97 (11.4%) had highest titers (1:204,800). Among the 2191 HIV-1 negative patients, the prevalence of high anti-HHV-8 antibody titers (≥1:51,200) was independently associated with increasing age (ptrend = 0.04), having a marital status of separated or divorced (p = 0.003), using wood, coal or charcoal as fuel for cooking 20 years ago instead of electricity (p = 0.02) and consuming traditional maize beer more than one time a week (p = 0.02; p-trend for increasing consumption = 0.05) although this may be due to chance given the large number of predictors considered in this analysis. Conclusions: Among HIV-negative subjects, patients with high anti-HHV-8 antibody titers are characterized by older age. Other associations that may be factors in the development of high anti- HHV-8 titers include exposure to poverty or a low socioeconomic status environment and consumption of traditional maize beer. The relationship between these variables and high anti- HHV-8 titers requires further, prospective study

    Stochastic Domination in Space-Time for the Contact Process

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    Liggett and Steif (2006) proved that, for the supercritical contact process \non certain graphs, the upper invariant measure stochastically dominates an \ni.i.d.\\ Bernoulli product measure. In particular, they proved this for \nmathbbZd\\mathbb{Z}^d and (for infection rate sufficiently large) dd-ary homogeneous \ntrees TdT_d. \n In this paper we prove some space-time versions of their results. We do this \nby combining their methods with specific properties of the contact process and \ngeneral correlation inequalities. \n One of our main results concerns the contact process on TdT_d with dgeq2d\\geq2. \nWe show that, for large infection rate, there exists a subset Delta\\Delta of the \nvertices of TdT_d, containing a "positive fraction" of all the vertices of \nTdT_d, such that the following holds: The contact process on TdT_d observed on \nDelta\\Delta stochastically dominates an independent spin-flip process. (This is \nknown to be false for the contact process on graphs having subexponential \ngrowth.) \n We further prove that the supercritical contact process on mathbbZd\\mathbb{Z}^d \nobserved on certain dd-dimensional space-time slabs stochastically dominates \nan i.i.d.\\ Bernoulli product measure, from which we conclude strong mixing \nproperties important in the study of certain random walks in random \nenvironment

    Efficacy and tolerability of evolocumab vs. ezetimibe in patients with muscle-related statin intolerance: the GAUSS-3 randomized clinical trial

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    Importance: Muscle-related statin intolerance is reported by 5% to 20% of patients. Objective: To identify patients with muscle symptoms confirmed by statin rechallenge and compare lipid-lowering efficacy for 2 nonstatin therapies, ezetimibe and evolocumab. Design, Setting, and Participants: Two-stage randomized clinical trial including 511 adult patients with uncontrolled low-density lipoprotein cholesterol (LDL-C) levels and history of intolerance to 2 or more statins enrolled in 2013 and 2014 globally. Phase A used a 24-week crossover procedure with atorvastatin or placebo to identify patients having symptoms only with atorvastatin but not placebo. In phase B, after a 2-week washout, patients were randomized to ezetimibe or evolocumab for 24 weeks. Interventions: Phase A: atorvastatin (20 mg) vs placebo. Phase B: randomization 2:1 to subcutaneous evolocumab (420 mg monthly) or oral ezetimibe (10 mg daily). Main Outcome and Measures: Coprimary end points were the mean percent change in LDL-C level from baseline to the mean of weeks 22 and 24 levels and from baseline to week 24 levels. Results: Of the 491 patients who entered phase A (mean age, 60.7 [SD, 10.2] years; 246 women [50.1%]; 170 with coronary heart disease [34.6%]; entry mean LDL-C level, 212.3 [SD, 67.9] mg/dL), muscle symptoms occurred in 209 of 491 (42.6%) while taking atorvastatin but not while taking placebo. Of these, 199 entered phase B, along with 19 who proceeded directly to phase B for elevated creatine kinase (N = 218, with 73 randomized to ezetimibe and 145 to evolocumab; entry mean LDL-C level, 219.9 [SD, 72] mg/dL). For the mean of weeks 22 and 24, LDL-C level with ezetimibe was 183.0 mg/dL; mean percent LDL-C change, −16.7% (95% CI, −20.5% to −12.9%), absolute change, −31.0 mg/dL and with evolocumab was 103.6 mg/dL; mean percent change, −54.5% (95% CI, −57.2% to −51.8%); absolute change, −106.8 mg/dL (P < .001). LDL-C level at week 24 with ezetimibe was 181.5 mg/dL; mean percent change, −16.7% (95% CI, −20.8% to −12.5%); absolute change, −31.2 mg/dL and with evolocumab was 104.1 mg/dL; mean percent change, −52.8% (95% CI, −55.8% to −49.8%); absolute change, −102.9 mg/dL (P < .001). For the mean of weeks 22 and 24, between-group difference in LDL-C was −37.8%; absolute difference, −75.8 mg/dL. For week 24, between-group difference in LDL-C was −36.1%; absolute difference, –71.7 mg/dL. Muscle symptoms were reported in 28.8% of ezetimibe-treated patients and 20.7% of evolocumab-treated patients (log-rank P = .17). Active study drug was stopped for muscle symptoms in 5 of 73 ezetimibe-treated patients (6.8%) and 1 of 145 evolocumab-treated patients (0.7%). Conclusions and Relevance: Among patients with statin intolerance related to muscle-related adverse effects, the use of evolocumab compared with ezetimibe resulted in a significantly greater reduction in LDL-C levels after 24 weeks. Further studies are needed to assess long-term efficacy and safety

    Evaluation of Norad’s use of knowledge in portfolio management

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    A few years ago, Norad published its strategy towards 2030 and was reorganised to better fit its responsibility for managing an increasing share of Norwegian development aid. The strategy stressed the importance of using knowledge and other insights to ensure effective and efficient management of funds. The purpose of this evaluation, carried out by Itad and CMI, is to provide evaluative evidence about the extent to which the approach to the use of knowledge is likely to improve the quality of Norad’s portfolio management and, ultimately, contribute to better development results. The evaluation is intented be a tool for practical lessons and learning. The evaluation has three objectives: Describe the current guidelines, set-up and practices in relation to knowledge-based portfolio management. Identify strengths and weaknesses in the existing set-up for and practice of knowledge-based portfolio management. Provide actionable recommendations that support further improvements in Norad’s approach to and use of knowledge in portfolio management

    IRIS study: a phase II study of the steroid sulfatase inhibitor Irosustat when added to an aromatase inhibitor in ER-positive breast cancer patients

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    Purpose: Irosustat is a first-generation, orally active, irreversible steroid sulfatase inhibitor. We performed a multicentre, open label phase II trial of the addition of Irosustat to a first-line aromatase inhibitor (AI) in patients with advanced BC to evaluate the safety of the combination and to test the hypothesis that the addition of Irosustat to AI may further suppress estradiol levels and result in clinical benefit. Experimental design: Postmenopausal women with ER-positive locally advanced or metastatic breast cancer who had derived clinical benefit from a first-line AI and who subsequently progressed were enrolled. The first-line AI was continued and Irosustat (40 mg orally daily) added. The primary endpoint was clinical benefit rate (CBR). Secondary endpoints included safety, tolerability, and pharmacodynamic end points. Results: Twenty-seven women were recruited, four discontinued treatment without response assessment. Based on local reporting, the CBR was 18.5% (95% CI 6.3–38.1%) on an intent to treat basis, increasing to 21.7% (95% CI 7.4–43.7%) by per-protocol analysis. In those patients that achieved clinical benefit (n = 5), the median (interquartile range) duration was 9.4 months (8.1–11.3) months. The median progression-free survival time was 2.7 months (95% CI 2.5–4.6) in both the ITT and per-protocol analyses. The most frequently reported grade 3/4 toxicities were dry skin (28%), nausea (13%), fatigue (13%), diarrhoea (8%), headache (7%), anorexia (7%) and lethargy (7%). Conclusions: The addition of Irosustat to aromatase inhibitor therapy resulted in clinical benefit with an acceptable safety profile. The study met its pre-defined success criterion by both local and central radiological assessments

    Current understanding of the human microbiome

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    Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature Medicine 24 (2018): 392–400, doi:10.1038/nm.4517.Our understanding of the link between the human microbiome and disease, including obesity, inflammatory bowel disease, arthritis and autism, is rapidly expanding. Improvements in the throughput and accuracy of DNA sequencing of the genomes of microbial communities associated with human samples, complemented by analysis of transcriptomes, proteomes, metabolomes and immunomes, and mechanistic experiments in model systems, have vastly improved our ability to understand the structure and function of the microbiome in both diseased and healthy states. However, many challenges remain. In this Review, we focus on studies in humans to describe these challenges, and propose strategies that leverage existing knowledge to move rapidly from correlation to causation, and ultimately to translation.Many of the studies described here in our laboratories were supported by the NIH, NSF, DOE, and the Alfred P. Sloan Foundation.2018-10-1

    L’influence des relations familiales et sociales sur la consommation de médicaments psychotropes chez les personnes âgées

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    Les psychotropes occupent le deuxième rang dans la consommation de médicaments chez les personnes âgées. L'objectif de cette étude est de vérifier un modèle explicatif de la consommation de psychotropes dans cette population. Notre principale hypothèse est que la qualité des relations qu'entretient une personne âgée avec autrui, et particulièrement avec ses enfants, a une influence directe sur son bien-être psychologique, lequel a une influence directe sur la non-consommation de psychotropes. Une enquête a été réalisée auprès d'un échantillon de 500 personnes âgées de 65 à 84 ans, vivant à domicile. Au cours des trois mois précédant l'entrevue, 31,8 % des répondants ont consommé des psychotropes. Les données empiriques n'ayant pas permis de vérifier le modèle théorique retenu, des analyses multivariées ont conduit à l'élaboration d'un modèle explicatif de la consommation qui met en évidence que le bien-être psychologique et la santé sont les meilleurs prédicteurs de cette consommation. Un bien-être psychologique élevé diminue la consommation alors qu'un mauvais état de santé l'augmente. Les relations sociales influencent directement le bien-être psychologique alors que les relations familiales ont un effet de moindre importance. Le modèle explicatif proposé explique 13 % du phénomène de la consommation de psychotropes chez les personnes âgées.Psychotropic drugs are the second most commonly used medication by Quebec's elderly. The objective of this study is to test a theoretical model of psychotropic drug use in the elderly. The principal hypothesis is that the quality of relationships the elderly person has with others, particularly with his or her children, has a direct influence on his or her psychological well-being, which, in turn, directly affects the consumption of psychotropic agents. A survey was conducted on a sample of 500 elderly people, aged 65-84 years, living at home. 31.8% of the respondents used psychotropic drugs during the three-month period preceding the interview. Path analysis led to the elaboration of a modified model for the consumption of psychotropic drugs by the elderly which indicates that the best predictors of consumption are both the psychological well-being and the state of health of the individual. More elevated is the psychological well-being, less is the consumption of psychotropic drugs, whereas poor health condition increases it. The quality of an individual's social relationships has a direct influence on his or her psychological well-being, whereas family relationships are of lesser importance. Our model accounts for 13% of the predictors of psychotropic consumption by the elderly
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