898 research outputs found

    Sequential therapy of anti-Nogo-A antibody treatment and treadmill training leads to cumulative improvements after spinal cord injury in rats

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    Intense training is the most clinically successful treatment modality following incomplete spinal cord injuries (SCIs). With the advent of plasticity enhancing treatments, understanding how treatments might interact when delivered in combination becomes critical. Here, we investigated a rational approach to sequentially combine treadmill locomotor training with antibody mediated suppression of the fiber growth inhibitory protein Nogo-A. Following a large but incomplete thoracic lesion, rats were immediately treated with either anti-Nogo-A or control antibody (2 weeks) and then either left untrained or step-trained starting 3 weeks after injury for 8 weeks. It was found that sequentially combined therapy improved step consistency and reduced toe dragging and climbing errors, as seen with training and anti-Nogo-A individually. Animals with sequential therapy also adopted a more parallel paw position during bipedal walking and showed greater overall quadrupedal locomotor recovery than individual treatments. Histologically, sequential therapy induced the greatest corticospinal tract sprouting caudally into the lumbar region and increased the number of serotonergic synapses onto lumbar motoneurons. Increased primary afferent sprouting and synapse formation onto lumbar motoneurons observed with anti-Nogo-A antibody were reduced by training. Animals with sequential therapy also showed the highest reduction of lumbar interneuronal activity associated with walking (c-fos expression). No treatment effects for thermal nociception, mechanical allodynia, or lesion volume were observed. The results demonstrate that sequential administration of anti-Nogo-A antibody followed in time with intensive locomotor training leads to superior recovery of lost locomotor functions, which is probably mediated by changes in the interaction between descending sprouting and local segmental networks after SCI

    Ultra-Sensitive Hot-Electron Nanobolometers for Terahertz Astrophysics

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    The background-limited spectral imaging of the early Universe requires spaceborne terahertz (THz) detectors with the sensitivity 2-3 orders of magnitude better than that of the state-of-the-art bolometers. To realize this sensitivity without sacrificing operating speed, novel detector designs should combine an ultrasmall heat capacity of a sensor with its unique thermal isolation. Quantum effects in thermal transport at nanoscale put strong limitations on the further improvement of traditional membrane-supported bolometers. Here we demonstrate an innovative approach by developing superconducting hot-electron nanobolometers in which the electrons are cooled only due to a weak electron-phonon interaction. At T<0.1K, the electron-phonon thermal conductance in these nanodevices becomes less than one percent of the quantum of thermal conductance. The hot-electron nanobolometers, sufficiently sensitive for registering single THz photons, are very promising for submillimeter astronomy and other applications based on quantum calorimetry and photon counting.Comment: 19 pages, 3 color figure

    Embodied neurology: an integrative framework for neurological disorders

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    From a systems biology perspective, the brain and spinal cord are interwoven with the body, through afferent and efferent synaptic connections—they are literally ‘embodied’ (Adams et al., 2013). Neurologists appreciate the embodied nature of neurological disorders in terms of diagnosis, classification and their understanding of the underlying pathophysiology. They routinely use a combination of physical examinations (e.g. scales that test motor, sensory and autonomic function) in conjunction with physiological, biochemical and anatomical measures (e.g. electrophysiology, serum and CSF, and radiology) of the peripheral and central nervous system. These measures often produce combinations of symptoms and signs that translate into conventional nosological classifications. While therapeutics focus on the ‘treatable’ cause of a disorder, it is difficult to separate out the impact on the patient due to the primary effects of a lesion/insult etc. and the effects of (possibly delayed) secondary processes that may be reasonable targets for interventions on their own. Moreover, standard neurological assessments often fail to distinguish between pathogenic and compensatory processes. This state of affairs calls for a better understanding of neurological disease within a formal framework that links pathology to phenomenology (i.e. symptoms, impairment and physical signs). We suggest that such a framework should pay special attention to the embodied nature of the nervous system and the implicit pathophysiological and compensatory processes that can be present throughout the neuroaxis. In particular, we postulate that reciprocal information flows, between the body and the nervous system, are crucial for understanding and treating neurological disorders. This framework aims to link pathology to phenomenology, while respecting the ‘embodied’ nature of the nervous system. If fully realized, the framework of embodied neurology has the potential to improve functional outcome following individualized treatment (i.e. precision neurology), promote successful translation of novel therapeutics into clinical use, and refine nosology in the context of disease heterogeneity.Our description of embodied neurology is largely theoretical and is based on a series of focused workshops. It draws on recent advances in biophysical modelling of functional (Deco et al., 2008) and microstructural processes and neuroimaging (Weiskopf et al., 2015). These advances—together with preclinical research—constitute the three tenets of embodied neurology: biophysical modelling, quantitative physiological measures (with an emphasis on non-invasive neuroimaging) and preclinical research on basic mechanisms. These three have a particular focus on the entire nervous system

    Evaluating predictive pharmacogenetic signatures of adverse events in colorectal cancer patients treated with fluoropyrimidines

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    The potential clinical utility of genetic markers associated with response to fluoropyrimidine treatment in colorectal cancer patients remains controversial despite extensive study. Our aim was to test the clinical validity of both novel and previously identified markers of adverse events in a broad clinical setting. We have conducted an observational pharmacogenetic study of early adverse events in a cohort study of 254 colorectal cancer patients treated with 5-fluorouracil or capecitabine. Sixteen variants of nine key folate (pharmacodynamic) and drug metabolising (pharmacokinetic) enzymes have been analysed as individual markers and/or signatures of markers. We found a significant association between TYMP S471L (rs11479) and early dose modifications and/or severe adverse events (adjusted OR = 2.02 [1.03; 4.00], p = 0.042, adjusted OR = 2.70 [1.23; 5.92], p = 0.01 respectively). There was also a significant association between these phenotypes and a signature of DPYD mutations (Adjusted OR = 3.96 [1.17; 13.33], p = 0.03, adjusted OR = 6.76 [1.99; 22.96], p = 0.002 respectively). We did not identify any significant associations between the individual candidate pharmacodynamic markers and toxicity. If a predictive test for early adverse events analysed the TYMP and DPYD variants as a signature, the sensitivity would be 45.5 %, with a positive predictive value of just 33.9 % and thus poor clinical validity. Most studies to date have been under-powered to consider multiple pharmacokinetic and pharmacodynamic variants simultaneously but this and similar individualised data sets could be pooled in meta-analyses to resolve uncertainties about the potential clinical utility of these markers

    Peer-Victimization and Mental Health Problems in Adolescents: Are Parental and School Support Protective?

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    The aim of this study was to investigate the frequency and effects of peer-victimization on mental health problems among adolescents. Parental and school support were assumed as protective factors that might interact with one another in acting as buffers for adolescents against the risk of peer-victimization. Besides these protective factors, age and gender were additionally considered as moderating factors. The Social and Health Assessment survey was conducted among 986 students aged 11–18 years in order to assess peer-victimization, risk and protective factors and mental health problems. For mental health problems, the Strengths and Difficulties Questionnaire (SDQ) was used. Effects of peer-victimization on mental health problems were additionally compared with normative SDQ data in order to obtain information about clinically relevant psychopathology in our study sample. Results of this study show that peer-victimization carries a serious risk for mental health problems in adolescents. School support is effective in both male and female adolescents by acting as a buffer against the effect of victimization, and school support gains increasing importance in more senior students. Parental support seems to be protective against maladjustment, especially in peer-victimized girls entering secondary school. Since the effect of peer-victimization can be reduced by parental and school support, educational interventions are of great importance in cases of peer-victimization

    Ion Trap in a Semiconductor Chip

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    The electromagnetic manipulation of isolated atoms has led to many advances in physics, from laser cooling and Bose-Einstein condensation of cold gases to the precise quantum control of individual atomic ion. Work on miniaturizing electromagnetic traps to the micrometer scale promises even higher levels of control and reliability. Compared with 'chip traps' for confining neutral atoms, ion traps with similar dimensions and power dissipation offer much higher confinement forces and allow unparalleled control at the single-atom level. Moreover, ion microtraps are of great interest in the development of miniature mass spectrometer arrays, compact atomic clocks, and most notably, large scale quantum information processors. Here we report the operation of a micrometer-scale ion trap, fabricated on a monolithic chip using semiconductor micro-electromechanical systems (MEMS) technology. We confine, laser cool, and measure heating of a single 111Cd+ ion in an integrated radiofrequency trap etched from a doped gallium arsenide (GaAs) heterostructure.Comment: 4 pages, 4 figure

    Transient Facial Nerve Paralysis (Bell's Palsy) following Intranasal Delivery of a Genetically Detoxified Mutant of Escherichia coli Heat Labile Toxin

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    BACKGROUND: An association was previously established between facial nerve paralysis (Bell's palsy) and intranasal administration of an inactivated influenza virosome vaccine containing an enzymatically active Escherichia coli Heat Labile Toxin (LT) adjuvant. The individual component(s) responsible for paralysis were not identified, and the vaccine was withdrawn. METHODOLOGY/PRINCIPAL FINDINGS: Subjects participating in two contemporaneous non-randomized Phase 1 clinical trials of nasal subunit vaccines against Human Immunodeficiency Virus and tuberculosis, both of which employed an enzymatically inactive non-toxic mutant LT adjuvant (LTK63), underwent active follow-up for adverse events using diary-cards and clinical examination. Two healthy subjects experienced transient peripheral facial nerve palsies 44 and 60 days after passive nasal instillation of LTK63, possibly a result of retrograde axonal transport after neuronal ganglioside binding or an inflammatory immune response, but without exaggerated immune responses to LTK63. CONCLUSIONS/SIGNIFICANCE: While the unique anatomical predisposition of the facial nerve to compression suggests nasal delivery of neuronal-binding LT-derived adjuvants is inadvisable, their continued investigation as topical or mucosal adjuvants and antigens appears warranted on the basis of longstanding safety via oral, percutaneous, and other mucosal routes

    Association between infection early in life and mental disorders among youth in the community: a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>The objective of this study was to examine the association between infection early in life and mental disorders among youth in the community.</p> <p>Methods</p> <p>Data were drawn from the MECA (Methods in Epidemiology of Child and Adolescent psychopathology), a community-based study of 1,285 youth in the United States conducted in 1992. Multiple logistic regression analyses were used to investigate the association between parent/caregiver-reported infection early in life and DSM/DISC diagnoses of mental disorders at ages 9-17.</p> <p>Results</p> <p>Infection early in life was associated with a significantly increased odds of major depression (OR = 3.9), social phobia (OR = 5.8), overanxious disorder (OR = 6.1), panic disorder (OR = 12.1), and oppositional defiant disorder (OR = 3.7).</p> <p>Conclusions</p> <p>These findings are consistent with and extend previous results by providing new evidence suggesting a link between infection early in life and increased risk of depression and anxiety disorders among youth. These results should be considered preliminary. Replication of these findings with longitudinal epidemiologic data is needed. Possible mechanisms are discussed.</p

    The Evolution of Compact Binary Star Systems

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    We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure
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