98 research outputs found

    Neuromuscular Electrical Stimulation as a Method to Maximize the Beneficial Effects of Muscle Stem Cells Transplanted into Dystrophic Skeletal Muscle

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    Cellular therapy is a potential approach to improve the regenerative capacity of damaged or diseased skeletal muscle. However, its clinical use has often been limited by impaired donor cell survival, proliferation and differentiation following transplantation. Additionally, functional improvements after transplantation are all-too-often negligible. Because the host microenvironment plays an important role in the fate of transplanted cells, methods to modulate the microenvironment and guide donor cell behavior are warranted. The purpose of this study was to investigate whether the use of neuromuscular electrical stimulation (NMES) for 1 or 4 weeks following muscle-derived stem cell (MDSC) transplantation into dystrophic skeletal muscle can modulate the fate of donor cells and enhance their contribution to muscle regeneration and functional improvements. Animals submitted to 4 weeks of NMES after transplantation demonstrated a 2-fold increase in the number of dystrophin+ myofibers as compared to control transplanted muscles. These findings were concomitant with an increased vascularity in the MDSC+NMES group when compared to non-stimulated counterparts. Additionally, animals subjected to NMES (with or without MDSC transplantation) presented an increased maximal specific tetanic force when compared to controls. Although cell transplantation and/or the use of NMES resulted in no changes in fatigue resistance, the combination of both MDSC transplantation and NMES resulted in a faster recovery from fatigue, when compared to non-injected and non-stimulated counterparts. We conclude that NMES is a viable method to improve MDSC engraftment, enhance dystrophic muscle strength, and, in combination with MDSC transplantation, improve recovery from fatigue. These findings suggest that NMES may be a clinically-relevant adjunct approach for cell transplantation into skeletal muscle. © 2013 Distefano et al

    Nonlinear porous medium flow with fractional potential pressure

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    We study a porous medium equation, with nonlocal diffusion effects given by an inverse fractional Laplacian operator. We pose the problem in n-dimensional space for all t>0 with bounded and compactly supported initial data, and prove existence of a weak and bounded solution that propagates with finite speed, a property that is nor shared by other fractional diffusion models.Comment: 32 pages, Late

    Light-induced spiral mass transport in azo-polymer films under vortex-beam illumination

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    When an azobenzene-containing polymer film is exposed to a non-uniform illumination, a light-induced mass migration process may be induced, leading to the formation of relief patterns on the polymer free surface. Despite a research effort of many years and several proposed models many aspects of this phenomenon remain not well understood. Here we report the appearance of spiral-shaped relief patterns on the polymer under the illumination of focused Laguerre-Gauss beams, having helical wavefront and an optical vortex at their axis. The induced spiral reliefs are sensitive to the vortex topological charge and to the wavefront handedness. These findings are unexpected, because the "doughnut"-shaped intensity profile of Laguerre- Gauss beams contains no information about the wavefront handedness. We propose a model that explains the main features of this phenomenon from the surface-mediated interference of the longitudinal and the transverse components of the optical field. These results may find applications in optical micro- and nanolithography and optical-field.Comment: Open Access at Journal Reference homepag

    Leptogenesis in a Realistic Supersymmetric Model of Inflation with a Low Reheat Temperature

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    We discuss leptogenesis in a realistic supersymmetric model of inflation with a low reheat temperature 1-10 GeV. The lepton asymmetry is generated by a decaying right handed sneutrino, which is produced after inflation during preheating. The inflationary model is based on a simple variant of the Next-to-Minimal Supersymmetric Standard model (NMSSM) which solves the \mu problem, called \phiNMSSM, where the additional singlet \phi plays the role of the inflaton in hybrid (or inverted hybrid) type models. The model is invariant under an approximate Peccei-Quinn symmetry which also solves the strong CP problem, and leads to an invisible axion with interesting cosmological consequences. We show how the baryon number of the universe and the nature of cold dark matter are determined by the same parameters controlling the strong CP problem, the \mu problem and the neutrino masses and mixing angles.Comment: 17 page, latex, 1 eps fi

    Early holocenic and historic mtDNA african signatures in the iberian peninsula: The andalusian region as a paradigm

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    Determining the timing, identity and direction of migrations in the Mediterranean Basin, the role of "migratory routes" in and among regions of Africa, Europe and Asia, and the effects of sex-specific behaviors of population movements have important implications for our understanding of the present human genetic diversity. A crucial component of the Mediterranean world is its westernmost region. Clear features of transcontinental ancient contacts between North African and Iberian populations surrounding the maritime region of Gibraltar Strait have been identified from archeological data. The attempt to discern origin and dates of migration between close geographically related regions has been a challenge in the field of uniparental-based population genetics. Mitochondrial DNA (mtDNA) studies have been focused on surveying the H1, H3 and V lineages when trying to ascertain north-south migrations, and U6 and L in the opposite direction, assuming that those lineages are good proxies for the ancestry of each side of the Mediterranean. To this end, in the present work we have screened entire mtDNA sequences belonging to U6, M1 and L haplogroups in Andalusians--from Huelva and Granada provinces--and Moroccan Berbers. We present here pioneer data and interpretations on the role of NW Africa and the Iberian Peninsula regarding the time of origin, number of founders and expansion directions of these specific markers. The estimated entrance of the North African U6 lineages into Iberia at 10 ky correlates well with other L African clades, indicating that U6 and some L lineages moved together from Africa to Iberia in the Early Holocene. Still, founder analysis highlights that the high sharing of lineages between North Africa and Iberia results from a complex process continued through time, impairing simplistic interpretations. In particular, our work supports the existence of an ancient, frequently denied, bridge connecting the Maghreb and Andalusia.Financial support was provided by the Spanish Ministry of Competitiveness through Research Project CGL2010-15191/BOS granted to RC and International Mobility Program Acciones Integradas Hispano-Portuguesas (PRI-AIBPT-2011-1004) granted to RC (Spain) and LP (Portugal) (http://www.mineco.gob.es/portal/site/mineco/idi). The E.C. Sixth Framework Programme under Contract n° ERAS-CT-2003-980409 (EUROCORES project of the European Science Foundation) also provided financial support to JMD for North African population research. CLH has a predoctoral fellowship granted by Complutense University. PS is supported by FCT Investigator Programme (IF/01641/2013). IPATIMUP (https://www.ipatimup.pt/) integrates the Instituto the Investigação em Saúde (i3S) Research Unit, which is partially supported by FCT, the Portuguese Foundation for Science and Technology. IPATIMUP is funded by FEDER funds through the Operational Programme for Competitiveness Factors - COMPETE and National Funds through the FCT - under the project PEst-C/SAU/LA0003/2013. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Thrombin-receptor antagonist vorapaxar in acute coronary syndromes

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    Background: Vorapaxar is a new oral protease-activated-receptor 1 (PAR-1) antagonist that inhibits thrombin-induced platelet activation. Methods: In this multinational, double-blind, randomized trial, we compared vorapaxar with placebo in 12,944 patients who had acute coronary syndromes without ST-segment elevation. The primary end point was a composite of death from cardiovascular causes, myocardial infarction, stroke, recurrent ischemia with rehospitalization, or urgent coronary revascularization. RESULTS: Follow-up in the trial was terminated early after a safety review. After a median follow-up of 502 days (interquartile range, 349 to 667), the primary end point occurred in 1031 of 6473 patients receiving vorapaxar versus 1102 of 6471 patients receiving placebo (Kaplan-Meier 2-year rate, 18.5% vs. 19.9%; hazard ratio, 0.92; 95% confidence interval [CI], 0.85 to 1.01; P = 0.07). A composite of death from cardiovascular causes, myocardial infarction, or stroke occurred in 822 patients in the vorapaxar group versus 910 in the placebo group (14.7% and 16.4%, respectively; hazard ratio, 0.89; 95% CI, 0.81 to 0.98; P = 0.02). Rates of moderate and severe bleeding were 7.2% in the vorapaxar group and 5.2% in the placebo group (hazard ratio, 1.35; 95% CI, 1.16 to 1.58; P<0.001). Intracranial hemorrhage rates were 1.1% and 0.2%, respectively (hazard ratio, 3.39; 95% CI, 1.78 to 6.45; P<0.001). Rates of nonhemorrhagic adverse events were similar in the two groups. Conclusions: In patients with acute coronary syndromes, the addition of vorapaxar to standard therapy did not significantly reduce the primary composite end point but significantly increased the risk of major bleeding, including intracranial hemorrhage. (Funded by Merck; TRACER ClinicalTrials.gov number, NCT00527943.

    Augmented acquisition of cocaine self-administration and altered brain glucose metabolism in adult female but not male rats exposed to a cannabinoid agonist during adolescence

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    Marijuana consumption during adolescence has been proposed to be a stepping stone for adult cocaine addiction. However, experimental evidence for this hypothesis is missing. In this work we chronically injected male and female Wistar rats with either the cannabinoid agonist CP 55,940 (CP; 0.4 mg/kg) or its corresponding vehicle. Adult acquisition (seven 30 min daily sessions) and maintenance (fourteen 2 h daily sessions) of cocaine self administration (1 mg/kg), food reinforced operant learning under conditions of normal (ad libitum access to food), and high motivation (food restriction schedule) were measured. Additionally, brain metabolic activity was analyzed by means of [18F] fluorodeoxyglucose positron emission tomography. During the acquisition phase, female CP treated rats showed a higher rate of cocaine self administration as compared to vehicle treated females and males; no differences were found between both male groups. This effect disappeared in the maintenance phase. Moreover, no differences among groups were evident in the food reinforced operant task, pointing to the cocaine specific nature of the effect seen in self administration rather than a general change in reward processing. Basal brain metabolic activity also changed in CP treated females when compared to their vehicle treated counterparts with no differences being found in the males; more specifically we observed a hyper activation of the frontal cortex and a hypo activation of the amygdalo entorhinal cortex. Our results suggest that a chronic exposure to cannabinoids during adolescence alters the susceptibility to acquire cocaine self administration, in a sex specific fashion. This increased susceptibility could be related to thechanges in brain metabolic activity induced by cannabinoids during adolescenceThis work was supported by Grants FIS G03/05 (Red de Trastornos Adictivos), BSO2001-1099, FIS 01-05-01, Plan Nacional sobre Drogas (PNSD) 2001–2003, PNSD 2004–2007, GR-SAL/0260/2004 to EA and Grants INT/2012/ 2002, CB06/01/0079, and CENIT (2006–2009) to MDPublicad

    Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

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    A measurement of the cosmic-ray spectrum for energies exceeding 4×10184{\times}10^{18} eV is presented, which is based on the analysis of showers with zenith angles greater than 6060^{\circ} detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×10185.3{\times}10^{18} eV, the "ankle", the flux can be described by a power law EγE^{-\gamma} with index γ=2.70±0.02(stat)±0.1(sys)\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)} followed by a smooth suppression region. For the energy (EsE_\text{s}) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25(stat)1.2+1.0(sys))×1019E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19} eV.Comment: Replaced with published version. Added journal reference and DO
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