1,003 research outputs found
Implementation of the cooperative learning methodology to the Biopharmaceutics and Pharmacokinetics subject
La convergencia dentro del marco Europeo de Educación Superior plantea la necesidad de introducir cambios en el sistema educativo universitario. En este sentido, la formación en la universidad debe asegurar el desarrollo integral y continuo de los nuevos profesionales. El modelo tradicional de enseñanza ligado a conocimientos disciplinares ha de sustituirse por una formación en competencias ligadas al desempeño profesional y a un saber hacer cualificado para cada situación concreta. Metodologías activas como el aprendizaje cooperativo (AC) son reconocidas como estrategias idóneas para alcanzar estas competencias.
En este entorno se plantea el objetivo de este trabajo como una experiencia de aprendizaje cooperativo que se está llevando a cabo con un grupo de alumnos de la asignatura de Biofarmacia y Farmacocinética en la Licenciatura de Farmacia. Este estudio forma parte del desarrollo de un proyecto de Innovación y Mejora de la Calidad Docente de la Universidad Complutense de Madrid (UCM 2009-276). Dentro del programa de la asignatura se han elegido aquellos temas que resultan más adecuados para los objetivos de esta modalidad de aprendizaje. El grupo en el que se ha llevado a cabo esta experiencia, es un grupo piloto (adscripción voluntaria para los alumnos) que cuenta con 63 alumnos. Se han formado 9 grupos de trabajo con la participación de 7 especialistas por grupo. Para la comunicación con los alumnos y la entrega de documentación de trabajo se ha utilizado el Campus Virtual de la UCM que utiliza la plataforma WebCT.The convergence in the European Higher Education Framework presents the need to make changes in the University Educational System. In this sense, the education in the University must ensure the all-round and continuous development of new professionals. The traditional model of education related to the knowledge of subjects must be substituted by the education in competences related to professional performance and qualification know-how for each particular situation. Active methodologies such as cooperative learning are recognized as suitable strategies to get those competences. In this environment, the objective of this work is presented as a cooperative learning experience that is carrying out with a group of students of Biopharmacy and Pharmacokinetic subject of the Pharmacy Grade. This study is part of the development of a Project of Innovation and Improvement of the Educational Quality in the Complutense University of Madrid. The topics that have been chosen from the whole program of the subject are the most suitable to reach the objectives of this learning method. This experience has been tested in a pilot group integrated by 63 voluntary students. Nine work groups have been formed with the participation of seven specialists in each group. The UCM Virtual Campus website (based on WebCT platform) has been used for communication with the students and documentation purposes
Controlled delivery of tauroursodeoxycholic acid from biodegradable microspheres slows retinal degeneration and vision loss in P23H rats
Successful drug therapies for treating ocular diseases require effective concentrations of neuroprotective compounds maintained over time at the site of action. The purpose of this work was to assess the efficacy of intravitreal controlled delivery of tauroursodeoxycholic acid (TUDCA) encapsulated in poly(D, L-lactic-co-glycolic acid) (PLGA) microspheres for the treatment of the retina in a rat model of retinitis pigmentosa. PLGA microspheres (MSs) containing TUDCA were produced by the O/W emulsion-solvent evaporation technique. Particle size and morphology were assessed by light scattering and scanning electronic microscopy, respectively. Homozygous P23H line 3 rats received a treatment of intravitreal injections of TUDCA-PLGA MSs. Retinal function was assessed by electroretinography at P30, P60, P90 and P120. The density, structure and synaptic contacts of retinal neurons were analyzed using immunofluorescence and confocal microscopy at P90 and P120. TUDCA-loaded PLGA MSs were spherical, with a smooth surface. The production yield was 78%, the MSs mean particle size was 23 mu m and the drug loading resulted 12.5 +/- 0.8 mu g TUDCA/mg MSs. MSs were able to deliver the loaded active compound in a gradual and progressive manner over the 28-day in vitro release study. Scotopic electroretinografic responses showed increased ERG a- and b-wave amplitudes in TUDCA-PLGA-MSstreated eyes as compared to those injected with unloaded PLGA particles.TUDCA-PLGAMSs- treated eyes showed more photoreceptor rows than controls. The synaptic contacts of photoreceptors with bipolar and horizontal cells were also preserved in P23H rats treated with TUDCA-PLGA MSs. This work indicates that the slow and continuous delivery of TUDCA from PLGA-MSs has potential neuroprotective effects that could constitute a suitable therapy to prevent neurodegeneration and visual loss in retinitis pigmentosa
Influence of chronic ocular hypertension on emmetropia: Refractive, structural and functional study in two rat models
Chronic ocular hypertension (OHT) influences on refraction in youth and causes glaucoma in adulthood. However, the origin of the responsible mechanism is unclear. This study analyzes the effect of mild-moderate chronic OHT on refraction and neuroretina (structure and function) in young-adult Long-Evans rats using optical coherence tomography and electroretinography over 24 weeks. Data from 260 eyes were retrospectively analyzed in two cohorts: an ocular normotension (ONT) cohort (20 mmHg), in which OHT was induced either by sclerosing the episcleral veins (ES group) or by injecting microspheres into the anterior chamber. A trend toward emmetropia was found in both cohorts over time, though it was more pronounced in the OHT cohort (p < 0.001), especially in the ES group (p = 0.001) and males. IOP and refraction were negatively correlated at week 24 (p = 0.010). The OHT cohort showed early thickening in outer retinal sectors (p < 0.050) and the retinal nerve fiber layer, which later thinned. Electroretinography demonstrated early supranormal amplitudes and faster latencies that later declined. Chronic OHT accelerates emmetropia in Long–Evans rat eyes towards slowly progressive myopia, with an initial increase in structure and function that reversed over time. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Novel use of plga microspheres to create an animal model of glaucoma with progressive neuroretinal degeneration
Progressive degeneration of neuroretinal tissue with maintained elevated intraocular pressure (IOP) to simulate chronic glaucoma was produced by intracameral injections of poly (lactic-co-glycolic) acid (PLGA) microspheres (Ms) in rat eyes. The right eye of 39 rats received different sizes of PLGA-Ms (2 µL suspension; 10% w/v): 14 with 38–20 µm Ms (Ms38/20 model) and 25 with 20–10 µm particles (Ms20/10 model). This novel glaucoma animal model was compared to the episcleral vein sclerosis (EPI) model (25 eyes). Injections were performed at baseline, two, four and six weeks. Clinical signs, IOP, retina and optic nerve thicknesses (using in vivo optical coherence tomography; OCT), and histological studies were performed. An IOP increment was observed in all three groups, however, the values obtained from the PLGA-Ms injection resulted lower with a better preservation of the ocular surface. In fact, the injection of Ms20/10 created a gentler, more progressive, and more sustained increase in IOP. This IOP alteration was correlated with a significant decrease in most OCT parameters and in histological ganglion-cell count for the three conditions throughout the eight-week follow-up. In all cases, progressive degeneration of the retina, retinal ganglion cells and optic nerve, simulating chronic glaucoma, was detected by OCT and corroborated by histological study. Results showed an alternative glaucoma model to the well-known episcleral vein model, which was simpler to perform, more reproducible and easier to monitor in vivo
Chronic glaucoma using biodegradable microspheres to induce intraocular pressure elevation. Six-month follow-up
Background: To compare two prolonged animal models of glaucoma over 24 weeks of follow-up. A novel pre-trabecular model of chronic glaucoma was achieved by injection of biodegradable poly lactic-co-glycolic acid (PLGA) microspheres (10–20 µm) (Ms20/10) into the ocular anterior chamber to progressively increase ocular hypertension (OHT). Methods: Rat right eyes were injected to induce OHT: 50% received a suspension of Ms20/10 in the anterior chamber at 0, 2, 4, 8, 12, 16 and 20 weeks, and the other 50% received a sclerosing episcleral vein injection biweekly (EPIm). Ophthalmological clinical signs, intraocular pressure (IOP), neuroretinal functionality measured by electroretinography (ERG), and structural analysis of the retina, retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) protocols using optical coherence tomography (OCT) and histological exams were performed. Results: Both models showed progressive neuroretinal degeneration (p < 0.05), and contralateral eye affectation. The Ms20/10 model showed a more progressive increase in IOP and better preservation of ocular surface. Although no statistical differences were found between models, the EPIm showed a tendency to produce thicker retinal and thinner GCL thicknesses, slower latency and smaller amplitude as measured using ERG, and more aggressive disturbances in retinal histology. In both models, while the GCL showed the greatest percentage loss of thickness, the RNFL showed the greatest and earliest rate of thickness loss. Conclusions: The intracameral model with biodegradable microspheres resulted more like the conditions observed in humans. It was obtained by a less-aggressive mechanism, which allows for adequate study of the pathology over longer periods. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Chronic Glaucoma Using Biodegradable Microspheres to Induce Intraocular Pressure Elevation. Six-Month Follow-Up
Altres ajuts: Rio Hortega Research Grant M17/00213, Research Group UCM 920415, UCM-Santander fellowship (CT17/17-CT17-18).Background: To compare two prolonged animal models of glaucoma over 24 weeks of follow-up. A novel pre-trabecular model of chronic glaucoma was achieved by injection of biodegradable poly lactic-co-glycolic acid (PLGA) microspheres (10-20 µm) (Ms20/10) into the ocular anterior chamber to progressively increase ocular hypertension (OHT). Methods: Rat right eyes were injected to induce OHT: 50% received a suspension of Ms20/10 in the anterior chamber at 0, 2, 4, 8, 12, 16 and 20 weeks, and the other 50% received a sclerosing episcleral vein injection biweekly (EPIm). Ophthalmological clinical signs, intraocular pressure (IOP), neuroretinal functionality measured by electroretinography (ERG), and structural analysis of the retina, retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) protocols using optical coherence tomography (OCT) and histological exams were performed. Results: Both models showed progressive neuroretinal degeneration (p < 0.05), and contralateral eye affectation. The Ms20/10 model showed a more progressive increase in IOP and better preservation of ocular surface. Although no statistical differences were found between models, the EPIm showed a tendency to produce thicker retinal and thinner GCL thicknesses, slower latency and smaller amplitude as measured using ERG, and more aggressive disturbances in retinal histology. In both models, while the GCL showed the greatest percentage loss of thickness, the RNFL showed the greatest and earliest rate of thickness loss. Conclusions: The intracameral model with biodegradable microspheres resulted more like the conditions observed in humans. It was obtained by a less-aggressive mechanism, which allows for adequate study of the pathology over longer periods
Mineralocorticoid receptor antagonism limits experimental choroidal neovascularization and structural changes associated with neovascular age-related macular degeneration.
Choroidal neovascularization (CNV) is a major cause of visual impairment in patients suffering from wet age-related macular degeneration (AMD), particularly when refractory to intraocular anti-VEGF injections. Here we report that treatment with the oral mineralocorticoid receptor (MR) antagonist spironolactone reduces signs of CNV in patients refractory to anti-VEGF treatment. In animal models of wet AMD, pharmacological inhibition of the MR pathway or endothelial-specific deletion of MR inhibits CNV through VEGF-independent mechanisms, in part through upregulation of the extracellular matrix protein decorin. Intravitreal injections of spironolactone-loaded microspheres and systemic delivery lead to similar reductions in CNV. Together, our work suggests MR inhibition as a novel therapeutic option for wet AMD patients unresponsive to anti-VEGF drugs
Transport of small anionic and neutral solutes through chitosan membranes: Dependence on cross-linking and chelation of divalent cations
Chitosan membranes were prepared by solvent casting and cross-linked with glutaraldehyde at several ratios
under homogeneous conditions. The cross-linking degree, varying from 0 to 20%, is defined as the ratio between
the total aldehyde groups and the amine groups of chitosan. Permeability experiments were conducted using a
side-by-side diffusion cell to determine the flux of small molecules of similar size but with different chemical
moieties, either ionized (benzoic acid, salicylic acid, and phthalic acid) or neutral (2-phenylethanol) at physiological
pH. The permeability of the different model molecules revealed to be dependent on the affinity of those structurally
similar molecules to chitosan. The permeability of the salicylate anion was significantly enhanced by the presence
of metal cations commonly present in biological fluids, such as calcium and magnesium, but remained unchanged
for the neutral 2-phenylethanol. This effect could be explained by the chelation of metal cations on the amine
groups of chitosan, which increased the partition coefficient. The cross-linking degree was also correlated with
the permeability and partition coefficient. The change in the permeation properties of chitosan to anionic solutes
in the presence of these metallic cations is an important result and should be taken into consideration when trying
to make in vitro predictions of the drug release from chitosan-based controlled release systems
Standalone vertex finding in the ATLAS muon spectrometer
A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011
Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC
Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson
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