1,470 research outputs found

    Synthesis and Characterization of Elongated-Shaped Silver Nanoparticles as a Biocompatible Anisotropic SERS Probe for Intracellular Imaging: Theoretical Modeling and Experimental Verification

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    Progress in the field of biocompatible SERS nanoparticles has promising prospects for biomedical applications. In this work, we have developed a biocompatible Raman probe by combining anisotropic silver nanoparticles with the dye rhodamine 6G followed by subsequent coating with bovine serum albumin. This nanosystem presents strong SERS capabilities in the near infrared (NIR) with a very high (2.7 × 107) analytical enhancement factor. Theoretical calculations reveal the effects of the electromagnetic and chemical mechanisms in the observed SERS effect for this nanosystem. Finite element method (FEM) calculations showed a considerable near field enhancement in NIR. Using density functional quantum chemical calculations, the chemical enhancement mechanism of rhodamine 6G by interaction with the nanoparticles was probed, allowing us to calculate spectra that closely reproduce the experimental results. The nanosystem was tested in cell culture experiments, showing cell internalization and also proving to be completely biocompatible, as no cell death was observed. Using a NIR laser, SERS signals could be detected even from inside cells, proving the applicability of this nanosystem as a biocompatible SERS probe.España, Regional Ministry of Economy, Junta de Andalucía, P07-FQM-02595 (to CC), P10-FQM-06615 (to JMOM), P10-CTS-6928 (to DP) and PAIDI2020 Program (FQM319 to RFM and CTS677 to DP)Junta de Andalucía, PI-0070/2008 (to PZ) and PI-0068/2008 (to DP

    Modification of betanodavirus virulence by substitutions in the 3’ terminal region of RNA2

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    Betanodaviruses have bi-segmented positive-sense RNA genomes, consisting of RNAs 1 and 2. For some members of the related genus alphanodavirus, the 3' terminal 50 nucleotides (nt) of RNA2, including a predicted stem-loop structure (3'SL), are essential for replication. We investigate the possible existence and role of a similar structure in a reassortant betanodavirus strain (RGNNV/SJNNV). In this study, we developed three recombinant strains containing nucleotide changes at positions 1408 and 1412. Predictive models showed stem-loop structures involving nt 1398–1421 of the natural reassortant whereas this structure is modified in the recombinant viruses harbouring point mutations r1408 and r1408– 1412, but not in r1412. Results obtained from infectivity assays showed differences between the reference strains and the mutants in both RNA1 and RNA2 synthesis. Moreover, an imbalance between the synthesis of both segments was demonstrated, mainly with the double mutant. All these results suggest an interaction between RNA1 and the 3' non-coding regions (3¢NCR) of RNA2. In addition, the significant attenuation of the virulence for Senegalese sole and the delayed replication of r1408–1412 in brain tissues may point to an interaction of RNA2 with host cellular proteinsThis work was supported by grant AGL2014-54532-C2-2-R from the Ministerio de Innovación y Competitividad (Spain), co-funded by FEDERS

    Excess of Yra1 RNA-Binding Factor Causes Transcription-Dependent Genome Instability, Replication Impairment and Telomere Shortening

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    Yra1 is an essential nuclear factor of the evolutionarily conserved family of hnRNP-like export factors that when overexpressed impairs mRNA export and cell growth. To investigate further the relevance of proper Yra1 stoichiometry in the cell, we overexpressed Yra1 by transforming yeast cells with YRA1 intron-less constructs and analyzed its effect on gene expression and genome integrity. We found that YRA1 overexpression induces DNA damage and leads to a transcription-associated hyperrecombination phenotype that is mediated by RNA:DNA hybrids. In addition, it confers a genome-wide replication retardation as seen by reduced BrdU incorporation and accumulation of the Rrm3 helicase. In addition, YRA1 overexpression causes a cell senescence-like phenotype and telomere shortening. ChIP-chip analysis shows that overexpressed Yra1 is loaded to transcribed chromatin along the genome and to Y’ telomeric regions, where Rrm3 is also accumulated, suggesting an impairment of telomere replication. Our work not only demonstrates that a proper stoichiometry of the Yra1 mRNA binding and export factor is required to maintain genome integrity and telomere homeostasis, but suggests that the cellular imbalance between transcribed RNA and specific RNA-binding factors may become a major cause of genome instability mediated by co-transcriptional replication impairment.España Ministerio de Ciencia e Innovación BFU2010-16372, BFU2013-42918Andalucía, Junta de Andalucía BIO102, CVI4567 and BIO123

    El Aprendizaje Basado en Problemas como herramienta para el estudio de los fenómenos geológicos

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    Para suscitar interés y motivar al alumnado de 4º de ESO de la materia de Biología y Geología, se ha diseñado una experiencia de enseñanza-aprendizaje fundamentada en una metodología de Aprendizaje Basado en Problemas (ABP). En este ABP se estudian las relaciones que existen, de manera no siempre evidente, entre los fenómenos geológicos y sus consecuencias biológicas, así como los procesos de causa-efecto presentes en la naturaleza. De este modo, se pretende mejorar el pensamiento crítico y abstracto de los estudiantes. La evaluación de esta buena práctica se ha realizado mediante una matriz de rúbrica, elaborada por el profesor y entregada previamente a los alumnos. Además, se ha incluido un cuestionario de evaluación de la actividad por parte de los estudiantes, resultando muy bien valorada por los mismos

    Metal dyshomeostasis based biomarkers for lung cancer diagnosis using human biofluids

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    Lung cancer (LC) is one of the most common causes of cancer-related deaths in the world and it is well known that trace elements play important roles in the carcinogenic process activating and inhibiting enzymatic reactions and metalloproteins, in which they usually participate as cofactors. A cross-sectional study was conducted on 48 lung cancer patients and 39 controls (56 men and 31 women), aged 44-76 years between March 2011 and June 2012. Eleven elements have been included in the study: V, Cr, Mn, Fe, Co, Cu, Zn, Se, Mo, Cd, and Pb, some of them considered toxic (V, Cd, Cr and Pb), while others are essential (Co, Mo, Se, Fe and Zn), and they have been analyzed by ICP-QQQ-MS in serum, urine and for the first time in bronchoalveolar lavage fluid (BALF). In order to understand the involvement of metals in this process, an analytical metallomic approach based on non-denaturing precipitation of proteins (NDPP) has been optimized for the fractionation of high molecular mass (HMM) and low molecular mass (LMM) metal species, in order to distinguish between metal species that affect the biological activity and toxicological potential of the elements. In this work, the NDPP followed by the analysis of metals by ICP-QQQ-MS has been applied for the first time to serum, urine and BALF samples from lung cancer patients and controls in order to get metal-size molecule profiles (MSMP), which can be used as metal-based biomarkers of altered metabolic processes such as oxidative stress and homeostasis. In this sense, we have demonstrated that several metals are good biomarkers when they are related to labile complexes, complexed with low molecular mass ligands, or in the form of metalloproteins (i.e. V and Cr in HMM and Cu in LMM), which has been described for the first time. On the other hand, metal dyshomeostasis biomarkers are proposed using metal ratios and correlations. Finally, the ratios between elements were shown to be important biomarkers for lung cancer in serum (V/Mn, V/Pb, V/Zn, Cr/Pb), urine (Cr/Cd, Mn/Cd, V/Cd, Co/Cd, Cd/Pb) and BALF (V/Cu), which reflects the dyshomeostasis of metals in lung cancer. In this sense, several metals are correlated to others suggesting also the existence of an interconnected homeostasis in lung cancer.The authors thank the Spanish Ministry of Economy and Competitiveness (CTM2015-67902-C2-1-P) and Regional Ministry of Economy, Innovation, Science and Employment (Andalusian Government. P12-FQM-0442). B. Callejon-Leblic thanks the Ministerio de Educacion for a predoctoral scholarship FPU13/03615. Finally, the authors are grateful to FEDER (European Community) (UNHU13-1E-1611 and UNHU15-CE-3140)

    Recomendaciones del Grupo GARIN para el manejo de pacientes no críticos con diabetes o hiperglucemia de estrés y nutrición artificial

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    Background & aims: By means of this update, the GARIN working group aims to define its position regarding the treatment of patients with diabetes or stress hyperglycaemia and artificial nutrition. In this area there are many aspects of uncertainty, especially in non-critically ill patients. Methods: Bibliographical review, and specific questions in advance were discussed and answered at a meeting in the form of conclusions. Results: We propose a definition of stress hyperglycaemia. The indications and access routes for artificial nutrition are no different in patients with diabetes/stress hyperglycaemia than in non-diabetics. The objective must be to keep pre-prandial blood glucose levels between 100 and 140 mg/dl and post-prandial levels between 140 and 180 mg/dl. Hyperglycemia can be prevented through systematic monitoring of capillary glycaemias and adequately calculate energy-protein needs. We recommend using enteral formulas designed for patients with diabetes (high monounsaturated fat) to facilitate metabolic control. The best drug treatment for treating hyperglycaemia/diabetes in hospitalised patients is insulin and we make recommendations for adapt the theoretical insulin action to the nutrition infusion regimen. We also addressed recommendations for future investigation. Conclusions: This recommendations about artificial nutrition in patients with diabetes or stress hyperglycaemia can add value to clinical work.Introducción y objetivos: En el tratamiento de los pacientes con diabetes o hiperglucemia de estrés y la nutrición artificial existen muchas áreas de incertidumbre, sobre todo en pacientes no críticos. El grupo de trabajo GARIN tiene como objetivo definir su posición en este campo. Material y métodos: Revisión bibliográfica previa y reunión presencial en la que se discutieron y contestaron preguntas específicas sobre el tema. Resultados: Proponemos una definición de hiperglucemia de estrés. Las indicaciones y las rutas de acceso a la nutrición artificial no difieren en los pacientes con hiperglucemia de estrés o diabetes respecto a los no diabéticos. El objetivo debe ser mantener los niveles de glucemia preprandial entre 100 y 140 mg/dl y postprandial entre 140 y 180 mg/dl. La hiperglucemia puede prevenirse a través de una monitorización sistemática de las glucemias capilares y un cálculo adecuado de las necesidades energético-proteicas. Recomendamos el uso de fórmulas enterales diseñadas para pacientes con diabetes (alto contenido en grasas monoinsaturadas) para facilitar el control metabólico. El mejor tratamiento farmacológico para tratar la hiperglucemia/diabetes en pacientes hospitalizados es la insulina, aconsejando adaptar la acción teórica de la insulina al régimen de infusión de la nutrición. También realizamos recomendaciones para investigaciones futuras. Conclusiones: Estas recomendaciones aportan respuestas concretas sobre cuestiones comunes en la asistencia a pacientes con diabetes o hiperglucemia de estrés y nutrición artificial

    Introducción al diseño de Cursos Cero para materias básicas del primer curso de Grado en Ciencias mediante enseñanza virtual

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    Evaluar, analizar la situación de partida de los alumnos de nuevo acceso al 1º curso de Grado en Facultades de Ciencias de la UCM (Biología, Óptica y Optometría y Química), y generar las bases para diseñar un Curso 0 de una materia básica, Química

    The metallome of lung cancer and its potential use as biomarker

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    Carcinogenesis is a very complex process in which metals have been found to be critically involved. In this sense, a disturbed redox status and metal dyshomeostasis take place during the onset and progression of cancer, and it is well-known that trace elements participate in the activation or inhibition of enzymatic reactions and metalloproteins, in which they usually participate as cofactors. Until now, the role of metals in cancer have been studied as an effect, establishing that cancer onset and progression affects the disturbance of the natural chemical form of the essential elements in the metabolism. However, it has also been studied as a cause, giving insights related to the high exposure of metals giving a place to the carcinogenic process. On the other hand, the chemical species of the metal or metallobiomolecule is very important, since it finally affects the biological activity or the toxicological potential of the element and their mobility across different biological compartments. Moreover, the importance of metal homeostasis and metals interactions in biology has also been demonstrated, and the ratios between some elements were found to be different in cancer patients; however, the interplay of elements is rarely reported. This review focuses on the critical role of metals in lung cancer, which is one of the most insidious forms of cancer, with special attention to the analytical approaches and pitfalls to extract metals and their species from tissues and biofluids, determining the ratios of metals, obtaining classification profiles, and finally defining the metallome of lung cancer.This research was funded by the projects CTM2015-67902-C-1-P from the Spanish Ministry of Economy and Competitiveness, and P12-FQM-0442 from the Regional Ministry of Economy, Innovation, Science and Employment (Andalusian Government, Spain). Projects Neumosur (8/2012 and 9/2015) and SEPAR (124/2012 and 091/2016). Belén Callejón Leblic thanks the Ministry of Education, Culture and Sport for a predoctoral scholarship. Finally, authors are grateful to FEDER (European Community) for financial support, grants number UNHU13-1E-1611 and UNHU15-CE-3140

    Accurate,robust and harmonized implementation of morpho-functional imaging in treatment planning for personalized radiotherapy

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    In this work we present a methodology able to use harmonized PET/CT imaging in dose painting by number (DPBN) approach by means of a robust and accurate treatment planning system. Image processing and treatment planning were performed by using a Matlab-based platform, called CARMEN, in which a full Monte Carlo simulation is included. Linear programming formulation was developed for a voxel-by-voxel robust optimization and a specific direct aperture optimization was designed for an efficient adaptive radiotherapy implementation. DPBN approach with our methodology was tested to reduce the uncertainties associated with both, the absolute value and the relative value of the information in the functional image. For the same H&N case, a single robust treatment was planned for dose prescription maps corresponding to standardized uptake value distributions from two different image reconstruction protocols: One to fulfill EARL accreditation for harmonization of [18F]FDG PET/CT image, and the other one to use the highest available spatial resolution. Also, a robust treatment was planned to fulfill dose prescription maps corresponding to both approaches, the dose painting by contour based on volumes and our voxel-by-voxel DPBN. Adaptive planning was also carried out to check the suitability of our proposal. Different plans showed robustness to cover a range of scenarios for implementation of harmonizing strategies by using the highest available resolution. Also, robustness associated to discretization level of dose prescription according to the use of contours or numbers was achieved. All plans showed excellent quality index histogram and quality factors below 2%. Efficient solution for adaptive radiotherapy based directly on changes in functional image was obtained. We proved that by using voxel-by-voxel DPBN approach it is possible to overcome typical drawbacks linked to PET/CT images, providing to the clinical specialist confidence enough for routinely implementation of functional imaging for personalized radiotherapy.Junta de Andalucía (FISEVI, reference project CTS 2482)European Regional Development Fund (FEDER
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