2,246 research outputs found

    Glioblastoma on a microfluidic chip: Generating pseudopalisades and enhancing aggressiveness through blood vessel obstruction events

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    Background: Glioblastoma (GBM) is one of the most lethal tumor types. Hypercellular regions, named pseudo- palisades, are characteristic in these tumors and have been hypothesized to be waves of migrating glioblastoma cells.These “waves” of cells are thought to be induced by oxygen and nutrient depletion caused by tumor-induced blood vessel occlusion. Although the universal presence of these structures in GBM tumors suggests that they may play an instrumental role in GBM’s spread and invasion, the recreation of these structures in vitro has remained challenging. Methods: Here we present a new microfluidic model of GBM that mimics the dynamics of pseudopalisade forma- tion.To do this, we embedded U-251 MG cells within a collagen hydrogel in a custom-designed microfluidic device. By controlling the medium flow through lateral microchannels, we can mimic and control blood-vessel obstruction events associated with this disease. Results: Through the use of this new system, we show that nutrient and oxygen starvation triggers a strong migratory process leading to pseudopalisade generation in vitro.These results validate the hypothesis of pseudo- palisade formation and show an excellent agreement with a systems-biology model based on a hypoxia-driven phenomenon. Conclusions: This paper shows the potential of microfluidic devices as advanced artificial systems capable of mod- eling in vivo nutrient and oxygen gradients during tumor evolution

    Biological Activity and Implications of the Metalloproteinases in Diabetic Foot Ulcers

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    Inadequate metabolic control predisposes diabetic patient to a series of complications on account of diabetes mellitus (DM). Among the most common complications of DM is neuropathy, which causes microvascular damage by hyperglycemia in the lower extremities which arrives characterized by a delayed closing. The global prevalence of diabetic neuropathy (DN) was 66% of people with diabetes in 2015, representing the principal cause of total or partial lower extremities amputation, with 22.6% of the patients with DN. Matrix metalloproteinases (MMPs) are involved in healing. The function that these mainly play is the degradation during inflammation that has as consequence the elimination of the extracellular matrix (ECM), the disintegration of the capillary membrane to give way to angiogenesis and cellular migration for the remodeling of damaged tissue. The imbalance in MMPs may increase the chronicity of a wound, what leads to chronic foot ulcers and amputation. This chapter focuses on the role of MMPs in diabetic wound healing

    Lifestyles, arterial aging, and its relationship with the intestinal and oral microbiota (MIVAS III study): a research protocol for a cross-sectional multicenter study

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    The microbiota is increasingly recognized as a significant factor in the pathophysiology of many diseases, including cardiometabolic diseases, with lifestyles probably exerting the greatest influence on the composition of the human microbiome. The main objectives of the study are to analyze the association of lifestyles (diet, physical activity, tobacco, and alcohol) with the gut and oral microbiota, arterial aging, and cognitive function in subjects without cardiovascular disease in the Iberian Peninsula. In addition, the study will examine the mediating role of the microbiome in mediating the association between lifestyles and arterial aging as well as cognitive function.Methods and analysisMIVAS III is a multicenter cross-sectional study that will take place in the Iberian Peninsula. One thousand subjects aged between 45 and 74 years without cardiovascular disease will be selected. The main variables are demographic information, anthropometric measurements, and habits (tobacco and alcohol). Dietary patterns will be assessed using a frequency consumption questionnaire (FFQ) and the Mediterranean diet adherence questionnaire. Physical activity levels will be evaluated using the International Physical Activity Questionnaire (IPAQ), Marshall Questionnaire, and an Accelerometer (Actigraph). Body composition will be measured using the Inbody 230 impedance meter. Arterial aging will be assessed through various means, including measuring medium intimate carotid thickness using the Sonosite Micromax, conducting analysis with pulse wave velocity (PWA), and measuring pulse wave velocity (cf-PWV) using the Sphygmocor System. Additional cardiovascular indicators such as Cardio Ankle Vascular Index (CAVI), ba-PWV, and ankle-brachial index (Vasera VS-2000®) will also be examined. The study will analyze the intestinal microbiota using the OMNIgene GUT kit (OMR−200) and profile the microbiome through massive sequencing of the 16S rRNA gene. Linear discriminant analysis (LDA), effect size (LEfSe), and compositional analysis, such as ANCOM-BC, will be used to identify differentially abundant taxa between groups. After rarefying the samples, further analyses will be conducted using MicrobiomeAnalyst and R v.4.2.1 software. These analyses will include various aspects, such as assessing α and β diversity, conducting abundance profiling, and performing clustering analysis.DiscussionLifestyle acts as a modifier of microbiota composition. However, there are no conclusive results demonstrating the mediating effect of the microbiota in the relationship between lifestyles and cardiovascular diseases. Understanding this relationship may facilitate the implementation of strategies for improving population health by modifying the gut and oral microbiota

    Clinical, biological, and prognostic implications of SF3B1 co-occurrence mutations in very low/low- and intermediate-risk MDS patients

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    SF3B1 is a highly mutated gene in myelodysplastic syndrome (MDS) patients, related to a specific subtype and parameters of good prognosis in MDS without excess blasts. More than 40% of MDS patients carry at least two myeloid-related gene mutations but little is known about the impact of concurrent mutations on the outcome of MDS patients. In applying next-generation sequencing (NGS) with a 117 myeloid gene custom panel, we analyzed the co-occurrence of SF3B1 with other mutations to reveal their clinical, biological, and prognostic implications in very low/low- and intermediate-risk MDS patients. Mutations in addition to those of SF3B1 were present in 80.4% of patients (median of 2 additional mutations/patient, range 0–5). The most frequently mutated genes were as follows: TET2 (39.2%), DNMT3A (25.5%), SRSF2 (10.8%), CDH23 (5.9%), and ASXL1, CUX1, and KMT2D (4.9% each). The presence of at least two mutations concomitant with that of SF3B1 had an adverse impact on survival compared with those with the SF3B1 mutation and fewer than two additional mutations (median of 54 vs. 87 months, respectively: p = 0.007). The co-occurrence of SF3B1 mutations with specific genes is also linked to a dismal prognosis: SRSF2 mutations were associated with shorter overall survival (OS) than SRSF2wt (median, 27 vs. 75 months, respectively; p = 0.001), concomitant IDH2 mutations (median OS, 11 [mut] vs. 75 [wt] months; p = 0.001), BCOR mutations (median OS, 11 [mut] vs. 71 [wt] months; p = 0.036), and NUP98 and STAG2 mutations (median OS, 27 and 11 vs. 71 months, respectively; p = 0.008 and p = 0.002). Mutations in CHIP genes (TET2, DNMT3A) did not significantly affect the clinical features or outcome. Our results suggest that a more comprehensive NGS study in low-risk MDS SF3B1mut patients is essential for a better prognostic evaluation.This work was supported by grants from the following: Contrato Rio Hortega, CM17/00171; Gerencia Regional de Salud (Castilla y León) para proyectos de investigación año 2018, 1850/A/18; Spanish Fondo de Investigaciones Sanitarias, PI15/01471, PI18/01500; Instituto de Salud Carlos III (ISCIII); European Regional Development Fund (ERDF) “Una manera de hacer Europa”; Consejería de Educación, Junta de Castilla y León (SA271P18); Proyectos de Investigación del SACYL, Spain, GRS1847/A/18, GRS1653/A17; SYNtherapy, Synthetic Lethality for Personalized Therapy-based Stratification In Acute Leukemia (ERAPERMED2018–275); ISCIII (AC18/00093), co-funded by ERDF/ESF, “Investing in your future”, by grants from Red Temática de Investigación Cooperativa en Cáncer (RTICC) (RD12/0036/0069) and Centro de Investigación Biomédica en Red de Cáncer (CIBERONC CB16/12/00233). JMHS is supported by a research grant from Fundación Española de Hematología y Hemoterapia. MM is currently supported by an Ayuda predoctoral de la Junta de Castilla y León from the Fondo Social Europeo (JCYL- EDU/556/2019 PhD scholarship)

    Ciudad-territorio sustentable. Procesos, actores y estructuras

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    En los últimos años, los estudios urbanos especializados insisten en que los procesos de urbanización por los que atraviesan los distintos países desarrollados, parecen dejar atrás las explicaciones de la urbanización industrial, han surgido otras construcciones y perspectivas unas más acabadas que otras (Indovina, 1998, la “ciudad difusa”; Dematteis 1998, ciudad sin centros; Nel-lo, 1998 ciudad sin confines, Soja, 2008, la exópolis). En suma se dice que se avanza hacia la urbanización generalizada, ello acaba con la larga trayectoria del funcionamiento y naturaleza de la ciudad moderna, el cambio urbano estructural actual, es nuevamente, consecuencia de la descentralización, difusión, redistribución del desarrollo, del crecimiento y las innovaciones ahora sobre una estructura en el territorio. Ha sido una mutación no sólo empírica sino que ha dado lugar a la confrontación teórica. El sistema urbano jerárquico ha reducido su valor interpretativo porque se han modificado los supuestos en los que se basaban las relaciones de dominio y dependencia de los centros principales, porque se han abaratado los costos de transporte y el efecto de la distancia ya no es una limitante absoluta, ahora los procesos productivos flexibles y descentralizados propician las relaciones técnicas horizontales con lo cual se consiguen economías de escala externas e internas a las empresas en un territorio ampliado y no sólo exclusivamente en la aglomeración económica (Precedo, 2003; Veltz, 1999; Boix, 2002; Camagni, 2005; De Santiago, 2008 y; Garmendia, 2010).El objetivo es examinar dentro de la descentralización del proceso urbano a la ciudad-territorio en América Latina, en particular en México. En contextos urbanos desarrollados se afirma la convergencia urbana con la apertura de las unidades funcionales de los sistemas urbanos donde operan redes e interrelaciones de desarrollo cualitativo en el territorio. América Latina registra evidencias empíricas poco claras, existe alta concentración de aquella economía que contribuye al crecimiento nacional, mientras la población se descentraliza rápidamente. México, es un caso de primacía urbana histórica aunque da paso a la formación de regiones urbanas, mismas que reproducen relaciones polarizadas y escasamente descentralizadas. De manera que, en tanto domine la concentración espacial económica, la ciudadterritorio se podrá presentar en el continente sólo con algunos rasgos en regiones urbanas con mayor desarrollo y crecimiento. Palabras claves: descentralización urbana, sistema urbano, ciudad-territorio

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13
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