Funciones no visuales de la retina: Razones para cuidar la retina en la ceguera total

La retina es una porción del sistema nervioso central formada por una red de neuronas especializadas que se localiza tapizando el interior del globo ocular. En este tejido, los estímulos luminosos desencadenan respuestas eléctricas y químicas que activan diferentes vías paralelas de transmisión de la información hacia distintas áreas del sistema nervioso. La vía clásica visual, “formadora de imágenes”, se inicia con el proceso de transformación de las señales luminosas en impulsos eléctricos a nivel de los fotorreceptores clásicos, conos y bastones. Las células ganglionares de la retina son las encargadas de enviar la información desde la retina al cerebro a través de sus axones, que forman el nervio óptico

Functional electrical simulation (F.E.S.) in stroke

Electrical stimulation is a physical therapist technic used on many different pathologies; stroke is a recent application field that involves specific adjustment parameters, wich are different from other pathologies, based on last neurosciences advances, specially related with the work way to obtain cognitive activation.pre-prin

Efectividad de la punción seca sobre la función y en la espasticidad del brazo afecto en pacientes con ictus en fase subaguda

Antecedentes: El ictus constituye un importante problema de salud y la afectación que causa en el brazo limita la independencia funcional de los pacientes. La punción seca es una técnica de reciente incorporación que puede ayudar a disminuir los efectos de la espasticidad sobre la función motora del brazo, la calidad de vida y el dolor. Objetivos: Determinar la efectividad de la punción seca profunda combinada con el tratamiento de fisioterapia habitual, frente a solo el tratamiento de fisioterapia habitual en la mejora funcional y la espasticidad del brazo afecto, así como en la calidad de vida percibida y en el dolor del brazo afecto en pacientes con ictus en fase subaguda. Métodos: Estudio cuasiexperimental con dos grupos. Tras un análisis de propensiones, fueron incluidos 80 pacientes divididos en dos grupos de igual número (intervención y control). Ambos grupos recibieron el tratamiento de fisioterapia habitual en el brazo afecto. El grupo de punción recibió además 6 sesiones de punción seca profunda administradas durante un periodo de 8 semanas. Antes y después de cada sesión de punción fueron evaluados mediante las escalas Fugl-Meyer para miembro superior, Modificación de la Escala de Ashworth Modificada (MMAS), Resistencia Pasiva al Movimiento (REPAS) y Escala de Puntuación Numérica del Dolor. Al inicio y al final del estudio se registró el estadio Brunnstrom de recuperación y el patrón postural del brazo y en las sesiones 1, 4 y 6 se administró la encuesta de calidad de vida Euro QoL 5D-5L. Resultados: En los pacientes tratados con punción seca profunda se redujo la espasticidad medida con la REPAS (p<0.001) y se disminuyó en al menos un punto la MMAS (p<0.05) mejorando el estadio Brunnstrom (p<0.05). No se encontraron cambios en la función motora del brazo afecto, calidad de vida ni en el dolor entre ambos grupos. El modelo de regresión mostró cómo mejoras en la función motora y la espasticidad se asociaron de manera significativa al tratamiento con punción seca profunda. Conclusiones: La punción seca profunda reduce la espasticidad y mejora el estadío de recuperación del brazo afecto en pacientes con ictus en fase subaguda. Sin embargo no se han podido constatar cambios significativos en la función motora, en la calidad de vida percibida ni en el dolor.Background: Stroke constitutes a major health problem which usually affects the upper limb, leading to limitations of the patients´ functional independence. Dry needling is a new technique that can help to reduce spasticity, improve upper limb motor function, pain and quality of life. Objectives: To evaluate the effectiveness of deep dry needling combined with the usual physiotherapy treatment, compared to only the usual physiotherapy treatment, on motor function and spasticity in the affected upper limb, perception of quality of life and pain in patients with stroke in the subacute phase. Methods: Quasiexperimental clinical study with two groups. Eighty patients were included in the study after a propensity score analysis was carried out. Patients were allocated to one of the two groups (intervention or control). Both groups received standard physiotherapy treatment on the affected upper limb. Additionally, the intervention group also received 6 sessions of Dry Needling during an eight-week period. Patients were evaluated before and after each session using the upper extremity portion of the Fugl-Meyer Scale, Modified Modified Ashworth Scale (MMAS), Resistance to Passive Movement (REPAS) and the Numeric Pain Rating Scale. The postural movement pattern of the arm and the Brunnstrom recovery stage were recorded at the beginning and at the end of the study, whereas the Euro QoL quality of life survey was completed in session 1, 4 and 6. Results: Patients treated with dry needling achieved a reduction in spasticity when measured with REPAS (p<0.001) and with the MMAS (p<0.05), decreasing at least one point each. There were also improvements in the Brunnstrom recovery stage (p<0.05). No changes were found in the motor function of the affected upper limb, the quality of life or pain between the two groups. The regression model showed how improvements in motor function and spasticity were significantly associated with the dry needling treatment.Discussion: Dry needling showed an improvement of spasticity and recovery stage in the affected upper limb in patients with stroke in the subacute phase. However, there were no significant changes in the motor function, perception of quality of life and pain levels

Treatment of the hemiplegic shoulder throught biofeedback: a case study

Motor learning requires feedback. When a person is acquiring a new skill, or modifying a previously acquired skill due to physical dysfunction, sensory feedback optimizes motor learning. Electromyography is a discipline that focuses on clinical and neurophysiological evaluation of neuromuscular pathology, and on certain aspects of CNS pathology (acquired or traumatic brain injury, etc.). Currently, use of biofeedback devices, amplifying the signal produced at the motor endplates, has allowed the introduction of this therapeutic tool to treatment of patients with acquired brain injury. Biofeedback can provide reinforcement of motor control improvements acquired through physiotherapy sessions, and help with development of specific sensorimotor skills, not only analytically, but also during occupational tasks. Availability of portable devices that are easy to use has allowed widespread application of biofeedback to functional improvement in activities of daily living.pre-prin

Retinal Vascular Degeneration in the Transgenic P23H Rat Model of Retinitis Pigmentosa

Retinitis pigmentosa (RP) is a group of inherited retinal degenerative diseases involving a progressive degeneration of photoreceptor cells. Following the loss of photoreceptors, retinal vascularization tends to decrease, which seems to play a role in the degenerative process of retinal cells. This study reports changes in retinal vascular network architecture in the P23H rat model of RP at different stages of retinal degeneration. Homozygous P23H line-3 rats of ages ranging from 18 days to 16 months were used in this study. Age-matched Sprague-Dawley (SD) rats were used as control animals. Vertical sections and wholemount retinas were immunolabeled for type IV collagen or stained using NADPH diaphorase histochemistry, and retinal vascular networks were drawn using a camera lucida. The superficial and deep capillary plexus (DCP) were fully developed at P18 in P23H rat retinas and showed no differences from the control animals. In 4-month-old P23H rat retinas, the superficial and intermediate capillary plexus were similar to those observed in age-matched SD rats, but a reduction in the DCP could be observed in these animals, with a significant decrease in both capillary density and capillary loops. At 16 months, the DCP was completely lost, and only vessels exhibiting an abnormal, tortuous dead-end could be observed. The middle capillary plexus had virtually disappeared at this age. Only perpendicular vessels connecting the superficial and DCP were found. The superficial plexus showed no changes in the vascular surface with age. In RP, photoreceptor loss is accompanied by degenerative changes in the retinal vascular network. The disruption of the capillary plexus, with loss of capillary density and capillary loops, can hamper the normal supply of oxygen and nutrients to retinal cells, thus accelerating retinal degeneration. Therefore, changes in retinal vascularization must be taken into account in the design of therapies targeting retinal degenerative diseases

Neuroprotective Effects of Tauroursodeoxicholic Acid Involves Vascular and Glial Changes in Retinitis Pigmentosa Model

Purpose: Retinitis pigmentosa is primarily characterized by a massive photoreceptor loss. But a global retinal remodeling occurs in later stages of the disease. At that phase, glial cells and retinal vasculature are also strongly affected. The main aim of the present work is to assess if the bile acid Tauroursodeoxicholic acid (TUDCA), which has a demonstrated neuroprotective effect in numerous neurodegenerative diseases, is able to prevent glial and vascular degeneration in the P23H rat retina. Methods: Homozygous P23H (line 3) animals were injected weekly with a TUDCA (500 mg/kg, i.p.) or vehicle solution, from the postnatal day (P) 21 to P120. Sprague-Dawley rats (SD) were used as control. Retinal cross-sections and wholemounts were immunostained using different glial and vascular markers and visualized with confocal microscopy. Retinal blood vessels were stained with nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemistry and retinal vascular networks were drawn by hand using a camera lucida. Results: At P120, the photoreceptor degeneration observed in P23H rats was accompanied by a reduction in the vascular network density and complexity at the deep capillary plexus. In addition, astrocytes showed gliotic features and the outer processes of Müller cells displayed an aberrant distribution in ring-shaped structures. When treated with TUDCA, P23H rats displayed better-preserved vessels and capillary loops in the deep capillary plexus which are associated with the partial preservation of photoreceptors. TUDCA treatment also increased the number of astrocytes and reduced the presence of Müller cell process clusters in the outer retina. Conclusion: This work suggests that, besides its neuroprotective effect on photoreceptor cells, TUDCA treatment also protects from vascular and glial degeneration, a fact that encourages the use of TUDCA as a powerful therapy for neurodegenerative diseases.The authors also acknowledge support from grants funded by the Spanish Ministry of Science and Innovation (FEDER-PID2019-106230RB-I00), Spanish Ministry of Universities (FPU18/02964), National Institute of Health Carlos III (RETICS-FEDER RD16/0008/0016), and Generalitat Valenciana (IDIFEDER/2017/064, PROMETEO/2021/024, GV/2020/028, and APOSTD/2020/245)

Natural Compounds from Saffron and Bear Bile Prevent Vision Loss and Retinal Degeneration

All retinal disorders, regardless of their aetiology, involve the activation of oxidative stress and apoptosis pathways. The administration of neuroprotective factors is crucial in all phases of the pathology, even when vision has been completely lost. The retina is one of the most susceptible tissues to reactive oxygen species damage. On the other hand, proper development and functioning of the retina requires a precise balance between the processes of proliferation, differentiation and programmed cell death. The life-or-death decision seems to be the result of a complex balance between pro- and anti-apoptotic signals. It has been recently shown the efficacy of natural products to slow retinal degenerative process through different pathways. In this review, we assess the neuroprotective effect of two compounds used in the ancient pharmacopoeia. On one hand, it has been demonstrated that administration of the saffron constituent safranal to P23H rats, an animal model of retinitis pigmentosa, preserves photoreceptor morphology and number, the capillary network and the visual response. On the other hand, it has been shown that systemic administration of tauroursodeoxycholic acid (TUDCA), the major component of bear bile, to P23H rats preserves cone and rod structure and function, together with their contact with postsynaptic neurons. The neuroprotective effects of safranal and TUDCA make these compounds potentially useful for therapeutic applications in retinal degenerative diseases.This research was supported by grants from the Spanish Ministry of Economy and Competitiveness-FEDER (BFU2012-36845), Instituto de Salud Carlos III (RETICS RD12/0034/0010), Asociación Retina Asturias, Fundación Jesús Gangoiti, Organización Nacional de Ciegos Españoles (ONCE) and FUNDALUCE

Persistent inflammatory state after photoreceptor loss in an animal model of retinal degeneration

Microglia act as the resident immune cells of the central nervous system, including the retina. In response to damaging stimuli microglia adopt an activated state, which can progress into a phagocytic phenotype and play a potentially harmful role by eliciting the expression and release of pro-inflammatory cytokines. The aim of the present study was to assess longitudinal changes in microglia during retinal degeneration in the homozygous P23H rat, a model of dominant retinitis pigmentosa. Microglial phenotypes, morphology and density were analyzed by immunohistochemistry, flow cytometry, and cytokine antibody array. In addition, we performed electroretinograms to evaluate the retinal response. In the P23H retina, sclera, choroid and ciliary body, inflammatory cells increased in number compared with the control at all ages analyzed. As the rats became older, a higher number of amoeboid MHC-II+ cells were observed in the P23H retina, which correlated with an increase in the expression of pro-inflammatory cytokines. These findings suggest that, in the P23H model, retinal neuroinflammation persists throughout the rat’s life span even after photoreceptor depletion. Therefore, the inclusion of anti-inflammatory drugs at advanced stages of the neurodegenerative process may provide better retinal fitness so the remaining cells could still be used as targets of cellular or gene therapies.This work was supported by grants from the Spanish Ministry of the Economy and Competitiveness-FEDER (BFU2012-36845, BFU2015-67139-R), Instituto de Salud Carlos III (RETICS-FEDER RD12/0034/0010), Organización Nacional de Ciegos Españoles (ONCE), Asociación Retina Asturias, FUNDALUCE and Fundación Jesús de Gangoiti Barrera

Banco de ensayos mecánicos con sistema oleo hidráulico automatizado

Es sabido que, desde sus inicios, la energía hidráulica de potencia tiene características que la hacen útil para múltiples aplicaciones. En el área de los ensayos mecánicos es ampliamente utilizada debido al reducido espacio ocupado y la capacidad de carga que la misma permite. Por estas razones, se realizó el desarrollo de un banco de ensayos mecánicos a partir de un sistema hidráulico el cual fue automatizado para lograr realizar ensayos específicos.Facultad de Ingenierí