2,344 research outputs found

    Appetite suppressants and valvular heart disease - a systematic review

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    Background Although appetite suppressants have been implicated in the development of valvular heart disease, the exact level of risk is still uncertain. Initial studies suggested that as many as 1 in 3 exposed patients were affected, but subsequent research has yielded substantially different figures. Our objective was to systematically assess the risk of valvular heart disease with appetite suppressants. Methods We accepted studies involving obese patients treated with any of the following appetite suppressants: fenfluramine, dexfenfluramine, and phentermine. Three types of studies were reviewed: controlled and uncontrolled observational studies, and randomized controlled trials. Outcomes of interest were echocardiographically detectable aortic regurgitation of mild or greater severity, or mitral regurgitation of moderate or greater severity. Results Of the 1279 patients evaluated in seven uncontrolled cohort studies, 236 (18%) and 60 (5%) were found to have aortic and mitral regurgitation, respectively. Pooled data from six controlled cohort studies yielded, for aortic regurgitation, a relative risk ratio of 2.32 (95% confidence intervals 1.79 to 3.01, p < 0.00001) and an attributable rate of 4.9%, and for mitral regurgitation, a relative risk ratio of 1.55 (95% confidence intervals 1.06 to 2.25, p = 0.02) with an attributable rate of 1.0%. Only one case of valvular heart disease was detected in 57 randomized controlled trials, but this was judged unrelated to drug therapy. Conclusions The risk of valvular heart disease is significantly increased by the appetite suppressants reviewed here. Nevertheless, when considering all the evidence, valvulopathy is much less common than suggested by the initial, less methodologically rigorous studies

    Pregabalin in fibromyalgia - responder analysis from individual patient data

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    <p>Abstract</p> <p>Background</p> <p>Population mean changes are difficult to use in clinical practice. Responder analysis may be better, but needs validating for level of response and treatment duration. A consensus group has defined what constitutes minimal, moderate, and substantial benefit based on pain intensity and Patient Global Impression of Change scores.</p> <p>Methods</p> <p>We obtained individual patient data from four randomised double blind trials of pregabalin in fibromyalgia lasting eight to 14 weeks. We calculated response for all efficacy outcomes using any improvement (≥ 0%), minimal improvement (≥ 15%), moderate improvement (≥ 30%), substantial improvement (≥ 50%), and extensive improvement (≥ 70%), with numbers needed to treat (NNT) for pregabalin 300 mg, 450 mg, and 600 mg daily compared with placebo.</p> <p>Results</p> <p>Information from 2,757 patients was available. Pain intensity and sleep interference showed reductions with increasing level of response, a significant difference between pregabalin and placebo, and a trend towards lower (better) NNTs at higher doses. Maximum response rates occurred at 4-6 weeks for higher levels of response, and were constant thereafter. NNTs (with 95% confidence intervals) for ≥ 50% improvement in pain intensity compared with placebo after 12 weeks were 22 (11 to 870) for pregabalin 300 mg, 16 (9.3 to 59) for pregabalin 450 mg, and 13 (8.1 to 31) for pregabalin 600 mg daily. NNTs for ≥ 50% improvement in sleep interference compared with placebo after 12 weeks were 13 (8.2 to 30) for pregabalin 300 mg, 8.4 (6.0 to 14) for pregabalin 450 mg, and 8.4 (6.1 to 14) for pregabalin 600 mg. Other outcomes had fewer respondents at higher response levels, but generally did not discriminate between pregabalin and placebo, or show any dose response. Shorter duration and use of 'any improvement' over-estimated treatment effect compared with longer duration and higher levels of response.</p> <p>Conclusions</p> <p>Responder analysis is useful in fibromyalgia, particularly for pain and sleep outcomes. Some fibromyalgia patients treated with pregabalin experience a moderate or substantial pain response that is consistent over time. Short trials using 'any improvement' as an outcome overestimate treatment effects.</p

    Strain-induced partially flat band, helical snake states, and interface superconductivity in topological crystalline insulators

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    Topological crystalline insulators in IV-VI compounds host novel topological surface states consisting of multi-valley massless Dirac fermions at low energy. Here we show that strain generically acts as an effective gauge field on these Dirac fermions and creates pseudo-Landau orbitals without breaking time-reversal symmetry. We predict the realization of this phenomenon in IV-VI semiconductor heterostructures, due to a naturally occurring misfit dislocation array at the interface that produces a periodically varying strain field. Remarkably, the zero-energy Landau orbitals form a flat band in the vicinity of the Dirac point, and coexist with a network of snake states at higher energy. We propose that the high density of states of this flat band gives rise to interface superconductivity observed in IV-VI semiconductor multilayers at unusually high temperatures, with non-BCS behavior. Our work demonstrates a new route to altering macroscopic electronic properties to achieve a partially flat band, and paves the way for realizing novel correlated states of matter.Comment: Accepted by Nature Physic

    Prognostic and therapeutic significance of carbohydrate antigen 19-9 as tumor marker in patients with pancreatic cancer

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    In pancreatic cancer ( PC) accurate determination of treatment response by imaging often remains difficult. Various efforts have been undertaken to investigate new factors which may serve as more appropriate surrogate parameters of treatment efficacy. This review focuses on the role of carbohydrate antigen 19- 9 ( CA 19- 9) as a prognostic tumor marker in PC and summarizes its contribution to monitoring treatment efficacy. We undertook a Medline/ PubMed literature search to identify relevant trials that had analyzed the prognostic impact of CA 19- 9 in patients treated with surgery, chemoradiotherapy and chemotherapy for PC. Additionally, relevant abstract publications from scientific meetings were included. In advanced PC, pretreatment CA 19- 9 levels have a prognostic impact regarding overall survival. Also a CA 19- 9 decline under chemotherapy can provide prognostic information for median survival. A 20% reduction of CA 19- 9 baseline levels within the first 8 weeks of chemotherapy appears to be sufficient to define a prognostic relevant subgroup of patients ('CA 19- 9 responder'). It still remains to be defined whether the CA 19- 9 response is a more reliable method for evaluating treatment efficacy compared to conventional imaging. Copyright (c) 2006 S. Karger AG, Basel

    The Role of Zinc in Depressed Pregnant and Non-Pregnant Women: A Systematic Review and Meta-Analysis

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    AbstractPerinatal depression is a depressive illness that affects 10–15% of women in the UK with an estimated cost of £1.8 billion/year. Zinc deficiency is associated with the development of mood disorders and zinc supplementation has been shown to help reduce the symptoms of depression. Women who are pregnant and breastfeeding are at risk of lower levels of zinc because of the high demand from the developing and feeding baby. However, studies in the perinatal period are limited. With a long-term aim of designing a randomised controlled trial (RCT) to examine if zinc supplementation reduces depressive symptoms in pregnant and lactating women;the objective of this review was to systematically evaluate previous RCTs assessing zinc supplementation and depressive symptoms, in order to establish a zinc dosing regimen with regards to Galenic formulation, unit dose and frequency. The review was conducted by independent reviewers in accordance with PRISMA guidelines and is registered at Prospero (CRD42017059205). The Allied and Complimentary Medicine, CINAHL, Embase, MEDLINE, PsycINFO, PubMed, and Cochrane databases were searched since records began, with no restrictions, for intervention trials assessing Galenic formulation, unit dose and frequency of zinc supplementation to reduce the symptoms of depression. From a total of 66 identified records, 7 articles met the inclusion and exclusion criteria; all assessed the effect of zinc supplementation on mood. Risk of bias was independently assessed using the standard ‘Cochrane risk of bias tool’. Overall, 5 of the 7 papers were rated as high-quality trials; of the other two, one was rated poor and the other fair but both had a number of learning points. Preliminary findings indicate at the end of supplementing zinc, depression scores were reduced significantly. In one study, the Beck score decreased in the placebo group, but this reduction was not significant compared to the baseline. In two of the studies there was a significant correlation between serum zinc and self-reported mood questionnaires. Results also suggest that 25 mg zinc supplementation combined with antidepressant drugs can be effective in the treatment of major depression in women. This supports other work where researchers supplemented 25 mg of elemental zinc for 12 weeks or longer and found a reduction of symptoms in both pregnant and non-pregnant women. Thus, an early conclusion is that 25 mg of elemental zinc is an effective dose for improving low mood and is achievable in a trial setting.</jats:p

    Superior olivary complex organization and cytoarchitecture may be correlated with function and catarrhine primate phylogeny

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    In the mammalian auditory system, the medial nucleus of the trapezoid body and the lateral superior olive (MNTB-LSO system) contribute to binaural intensity processing and lateralization. Localization precision varies with the sound frequencies. As recency of common ancestry with human beings increases, primates have improved low-frequency sensitivity and reduced sensitivity to higher frequencies. The medial part of the MNTB is devoted to higher frequency processing. Thus, its high-frequency-dependent function is nearly lost in humans and its role in binaural processing as part of the contralateral pathway to the LSO remains questionable. Here, Nissl-stained sections of the superior olivary complex of man (Homo sapiens), bonobo (Pan paniscus), chimpanzee (Pan troglodytes), gorilla (Gorilla gorilla), orangutan (Pongo pygmaeus), gibbon (Hylobates lar), and macaque (Macaca fascicularis) were compared to reveal differences and coincidences. From chimpanzees to humans, the size of the LSO decreased, and the MNTB as a compact nucleus nearly disappears. From chimpanzees to humans, the LSO/MNTB ratio increases dramatically too, whereas the LSO/MSO ratio remains 1.1; a finding that probably corresponds to the phylogenetic proximity between the species

    Surface and Temporal Biosignatures

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    Recent discoveries of potentially habitable exoplanets have ignited the prospect of spectroscopic investigations of exoplanet surfaces and atmospheres for signs of life. This chapter provides an overview of potential surface and temporal exoplanet biosignatures, reviewing Earth analogues and proposed applications based on observations and models. The vegetation red-edge (VRE) remains the most well-studied surface biosignature. Extensions of the VRE, spectral "edges" produced in part by photosynthetic or nonphotosynthetic pigments, may likewise present potential evidence of life. Polarization signatures have the capacity to discriminate between biotic and abiotic "edge" features in the face of false positives from band-gap generating material. Temporal biosignatures -- modulations in measurable quantities such as gas abundances (e.g., CO2), surface features, or emission of light (e.g., fluorescence, bioluminescence) that can be directly linked to the actions of a biosphere -- are in general less well studied than surface or gaseous biosignatures. However, remote observations of Earth's biosphere nonetheless provide proofs of concept for these techniques and are reviewed here. Surface and temporal biosignatures provide complementary information to gaseous biosignatures, and while likely more challenging to observe, would contribute information inaccessible from study of the time-averaged atmospheric composition alone.Comment: 26 pages, 9 figures, review to appear in Handbook of Exoplanets. Fixed figure conversion error

    Search for time-dependent B0s - B0s-bar oscillations using a vertex charge dipole technique

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    We report a search for B0s - B0s-bar oscillations using a sample of 400,000 hadronic Z0 decays collected by the SLD experiment. The analysis takes advantage of the electron beam polarization as well as information from the hemisphere opposite that of the reconstructed B decay to tag the B production flavor. The excellent resolution provided by the pixel CCD vertex detector is exploited to cleanly reconstruct both B and cascade D decay vertices, and tag the B decay flavor from the charge difference between them. We exclude the following values of the B0s - B0s-bar oscillation frequency: Delta m_s < 4.9 ps-1 and 7.9 < Delta m_s < 10.3 ps-1 at the 95% confidence level.Comment: 18 pages, 3 figures, replaced by version accepted for publication in Phys.Rev.D; results differ slightly from first versio

    We can guide search by a set of colours, but are reluctant to do it.

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    For some real-world color searches, the target colours are not precisely known, and any item within a range of color values should be attended. This, a target representation that captures multiple similar colours would be advantageous. If such multicolour search is possible, then search for two targets (e..g Stroud, Menneer, Cave and Donnelly, 2012) might be guided by a target representation that included the target colours as well as the continuum of colours that fall between the targets within a contiguous region of color space. Results from Stroud et al (2012) suggest otherwise, however. The current set of experiments show that guidance for a set of colours that are from a single region of color space can be effective if targets are depicted as specific discrete colours. Specifically, Experiments 1-3 demonstrate that a search can be guided by four and even eight colours given the appropriate conditions. However, Experiment 5 gives evidence that guidance is sometimes sensitive to how informative the target preview is to search. Experiments 6 and 7 show that a stimulus showing a continuous range of target colours is not translated into a search target representation. Thus, search can be guided by multiple discrete colours that are from a single region in color space, but this approach was not adopted in a search for two targets with intervening distractor colours
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