239 research outputs found

    A trial of intracranial pressure monitoring in traumatic brain injury

    Get PDF
    Background Intracranial pressure (ICP) monitoring is considered the standard of care for severe traumatic brain injury (TBI) and is used frequently, but the efficacy of treatment based on monitoring in improving the outcome has not been rigorously assessed. Methods Objective: The objective was to compare efficacy of guideline-based management in which a protocol for monitoring intraparenchymal ICP was used (ICP group) or a protocol in which treatment was based on imaging and clinical examination (exam group). Design: A multicenter randomized controlled trial was conducted. Setting: The trial was set in ICUs in Bolivia or Ecuador. Subjects: Patients had severe TBI (n = 324) and were 13 years of age or older. Interventions: Patients were randomly allocated to ICP This composite measure was based on performance across 21 measures of functional and cognitive status and was calculated as a percentile (with 0 indicating the worst performance, and 100 the best performance). Results There was no significant between-group difference in the primary outcome, a composite measure based on percentile performance across 21 measures of functional and cognitive status (score 56 in the pressure-monitoring group versus 53 in the imaging-clinical examination group; P= 0.49). Six-month mortality rates were 39% in the pressuremonitoring group and 41% in the imaging-clinical examination group (P = 0.60). The median lengths of stay in the ICU were similar in the two groups (12 days in the pressure-monitoring group and 9 days in the imagingclinical examination group; P = 0.25), although the number of days of brain-specific treatments (for example, administration of hyperosmolar fluids and the use of hyperventilation) in the ICU was higher in the imaging-clinical examination group than in the pressure-monitoring group (4.8 versus 3.4, P = 0.002). The distributions of serious adverse events were similar in the two groups. Conclusions For patients with severe TBI, care focused on maintaining monitored ICP at 20 mmHg or less was not shown to be superior to care based on imaging and clinical examination. monitoring or clinical exam-based monitoring. Outcomes: The primary outcome was a composite of survival time, impaired consciousness, functional status at 3 and 6 months, and neuropsychological status at 6 months; neuropsychological status was assessed by an examiner who was unaware of the protocol assignment. © 2014 BioMed Central Ltd

    Regulation of insulin-like growth factor–dependent myoblast differentiation by Foxo forkhead transcription factors

    Get PDF
    Insulin-like growth factors promote myoblast differentiation through phosphoinositol 3-kinase and Akt signaling. Akt substrates required for myogenic differentiation are unknown. Forkhead transcription factors of the forkhead box gene, group O (Foxo) subfamily are phosphorylated in an insulin-responsive manner by phosphatidylinositol 3-kinase–dependent kinases. Phosphorylation leads to nuclear exclusion and inactivation. We show that a constitutively active Foxo1 mutant inhibits differentiation of C2C12 cells and prevents myotube differentiation induced by constitutively active Akt. In contrast, a transcriptionally inactive mutant Foxo1 partially rescues inhibition of C2C12 differentiation mediated by wortmannin, but not by rapamycin, and is able to induce aggregation-independent myogenic conversion of teratocarcinoma cells. Inhibition of Foxo expression by siRNA resulted in more efficient differentiation, associated with increased myosin expression. These observations indicate that Foxo proteins are key effectors of Akt-dependent myogenesis

    Age-dependent white matter disruptions after military traumatic brain injury: Multivariate analysis results from ENIGMA brain injury

    Get PDF
    Mild Traumatic brain injury (mTBI) is a signature wound in military personnel, and repetitive mTBI has been linked to age-related neurogenerative disorders that affect white matter (WM) in the brain. However, findings of injury to specific WM tracts have been variable and inconsistent. This may be due to the heterogeneity of mechanisms, etiology, and comorbid disorders related to mTBI. Non-negative matrix factorization (NMF) is a data-driven approach that detects covarying patterns (components) within high-dimensional data. We applied NMF to diffusion imaging data from military Veterans with and without a self-reported TBI history. NMF identified 12 independent components derived from fractional anisotropy (FA) in a large dataset (n = 1,475) gathered through the ENIGMA (Enhancing Neuroimaging Genetics through Meta-Analysis) Military Brain Injury working group. Regressions were used to examine TBI- and mTBI-related associations in NMF-derived components while adjusting for age, sex, post-traumatic stress disorder, depression, and data acquisition site/scanner. We found significantly stronger age-dependent effects of lower FA in Veterans with TBI than Veterans without in four components (q \u3c 0.05), which are spatially unconstrained by traditionally defined WM tracts. One component, occupying the most peripheral location, exhibited significantly stronger age-dependent differences in Veterans with mTBI. We found NMF to be powerful and effective in detecting covarying patterns of FA associated with mTBI by applying standard parametric regression modeling. Our results highlight patterns of WM alteration that are differentially affected by TBI and mTBI in younger compared to older military Veterans

    Low-Dosage Inhibition of DII4 Signaling Promotes Wound Healing by Inducing Functional Neo-Angiogenesis

    Get PDF
    Recent findings regarding Dll4 function in physiological and pathological conditions indicate that this Notch ligand may constitute an important therapeutic target. Dll4 appears to be a major anti-angiogenic agent, occupying a central role in various angiogenic pathways. The first trials of anti-Dll4 therapy in mice demonstrated a paradoxical effect, as it reduced tumor perfusion and growth despite leading to an increase in vascular density. This is seen as the result of insufficient maturation of the newly formed vasculature causing a circulatory defect and increased tumor hypoxia. As Dll4 function is known to be closely dependent on expression levels, we envisioned that the therapeutic anti-Dll4 dosage could be modulated to result in the increase of adequately functional blood vessels. This would be useful in conditions where vascular function is a limiting factor for recovery, like wound healing and tissue hypoxia, especially in diabetic patients. Our experimental results in mice confirmed this possibility, revealing that low dosage inhibition of Dll4/Notch signaling causes improved vascular function and accelerated wound healing

    Influence of Dll4 via HIF-1α-VEGF Signaling on the Angiogenesis of Choroidal Neovascularization under Hypoxic Conditions

    Get PDF
    Choroidal neovascularization (CNV) is the common pathological basis of irreversible visual impairment encountered in a variety of chorioretinal diseases; the pathogenesis of its development is complicated and still imperfectly understood. Recent studies indicated that delta-like ligand 4 (Dll4), one of the Notch family ligands might participate in the HIF-1α-VEGF pathway to regulate CNV angiogenesis. But little is known about the influence and potential mechanism of Dll4/Notch signals on CNV angiogenesis. Real-time RT-PCR, Western blotting were used to analyze the expression alteration of Dll4, VEGF and HIF-1α in hypoxic RF/6A cells. Immunofluorescence staining, a laser-induced rat CNV model and intravitreal injection techniques were used to confirm the relationships among these molecules in vitro and in vivo. RPE-RF/6A cell co-culture systems were used to investigate the effects of Dll4/Notch signals on CNV angiogenesis. We found that the Dll4 was involved in hypoxia signaling in CNV angiogenesis. Results from the co-culture system showed that the enhancement of Dll4 expression in RF/6A cells led to the significantly faster proliferation and stronger tube forming ability, but inhibited cells migration and invasion across a monolayer of RPE cells in hypoxic environment, while siRNA-mediated Dll4 silencing caused the opposite effects. Pharmacological disruption of Notch signaling using gamma-secretase inhibitor (GSI) produced similar, but not identical effects, to that caused by the Dll4 siRNA. In addition, the expression of several key molecules involved in the angiogenesis of CNV was altered in RF/6A cells showing constitutively active Dll4 expression. These results suggest that Dll4 play an important role in CNV angiogenesis, which appears to be regulated by HIF-1α and VEGF during the progression of CNV under hypoxic conditions. Targeting Dll4/Notch signaling may facilitate further understanding of the mechanisms that underlie CNV angiogenesis

    Early management of adult traumatic spinal cord injury in patients with polytrauma: a consensus and clinical recommendations jointly developed by the World Society of Emergency Surgery (WSES) & the European Association of Neurosurgical Societies (EANS)

    Get PDF
    Background: The early management of polytrauma patients with traumatic spinal cord injury (tSCI) is a major challenge. Sparse data is available to provide optimal care in this scenario and worldwide variability in clinical practice has been documented in recent studies. Methods: A multidisciplinary consensus panel of physicians selected for their established clinical and scientific expertise in the acute management of tSCI polytrauma patients with different specializations was established. The World Society of Emergency Surgery (WSES) and the European Association of Neurosurgical Societies (EANS) endorsed the consensus, and a modified Delphi approach was adopted. Results: A total of 17 statements were proposed and discussed. A consensus was reached generating 17 recommendations (16 strong and 1 weak). Conclusions: This consensus provides practical recommendations to support a clinician’s decision making in the management of tSCI polytrauma patients

    Metabolic changes in concussed American football players during the acute and chronic post-injury phases

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Despite negative neuroimaging findings many athletes display neurophysiological alterations and post-concussion symptoms that may be attributable to neurometabolic alterations.</p> <p>Methods</p> <p>The present study investigated the effects of sports concussion on brain metabolism using <sup>1</sup>H-MR Spectroscopy by comparing a group of 10 non-concussed athletes with a group of 10 concussed athletes of the same age (mean: 22.5 years) and education (mean: 16 years) within both the acute and chronic post-injury phases. All athletes were scanned 1-6 days post-concussion and again 6-months later in a 3T Siemens MRI.</p> <p>Results</p> <p>Concussed athletes demonstrated neurometabolic impairment in prefrontal and motor (M1) cortices in the acute phase where NAA:Cr levels remained depressed relative to controls. There was some recovery observed in the chronic phase where Glu:Cr levels returned to those of control athletes; however, there was a pathological increase of m-I:Cr levels in M1 that was only present in the chronic phase.</p> <p>Conclusions</p> <p>These results confirm cortical neurometabolic changes in the acute post-concussion phase as well as recovery and continued metabolic abnormalities in the chronic phase. The results indicate that complex pathophysiological processes differ depending on the post-injury phase and the neurometabolite in question.</p

    Contested space: The contradictory political dynamics of food banking in the UK

    Get PDF
    This paper offers a critical reappraisal of the politics of food banking in the UK. Existing work has raised concerns about the institutionalisation of food banks, with charitable assistance apparently – even if inadvertently – undermining collectivist welfare and deflecting attention from fundamental injustices in the food system. This paper presents original ethnographic work that examines the neglected politics articulated within food banks themselves. Conceptualising food banks as potential spaces of encounter where predominantly middle-class volunteers come into contact with ‘poor others’ (Lawson and Elwood, 2013), we illustrate the ways food banks may both reinforce but also rework and generate new, ethical and political attitudes, beliefs and identities. We also draw attention to the limits of these progressive possibilities and examine the ways in which some food banks continue to operate within a set of highly restrictive, and stigmatising, welfare technologies. By highlighting the contradictory dynamics at work in food bank organisations, and among food bank volunteers and clients, we suggest the political role of food banks warrants neither uncritical celebration nor outright dismissal. Rather, food banks represent a highly ambiguous political space still in the making and open to contestatio
    corecore