Neuroprotective Effect of Tauroursodeoxycholic Acid on N-Methyl-D-Aspartate-Induced Retinal Ganglion Cell Degeneration

Retinal ganglion cell degeneration underlies the pathophysiology of diseases affecting the retina and optic nerve. Several studies have previously evidenced the anti-apoptotic properties of the bile constituent, tauroursodeoxycholic acid, in diverse models of photoreceptor degeneration. The aim of this study was to investigate the effects of systemic administration of tauroursodeoxycholic acid on N-methyl-D-aspartate (NMDA)-induced damage in the rat retina using a functional and morphological approach. Tauroursodeoxycholic acid was administered intraperitoneally before and after intravitreal injection of NMDA. Three days after insult, full-field electroretinograms showed reductions in the amplitudes of the positive and negative-scotopic threshold responses, scotopic a- and b-waves and oscillatory potentials. Quantitative morphological evaluation of whole-mount retinas demonstrated a reduction in the density of retinal ganglion cells. Systemic administration of tauroursodeoxycholic acid attenuated the functional impairment induced by NMDA, which correlated with a higher retinal ganglion cell density. Our findings sustain the efficacy of tauroursodeoxycholic acid administration in vivo, suggesting it would be a good candidate for the pharmacological treatment of degenerative diseases coursing with retinal ganglion cell loss.

La comunicación en la red de pacientes con enfermedades raras en España

Introducción: Este estudio se centra en la estrategia de comunicación de las organizaciones de pacientes con enfermedades raras en internet. Objetivo: Analizar la utilización de las herramientas de comunicación en internet. Métodos: Se examinaron 143 organizaciones de pacientes nacionales. Se ha realizado un análisis de contenido de cada una de las webs de las organizaciones, redes sociales y blogs. Y se han llevado a cabo encuestas telefónicas a 90 organizaciones con las que se contactó, el 63% del total. Resultados: El 84% de las web está gestionada por miembros de las organizaciones sin formación específica y el 16% por profesionales. Se dirigen en la misma proporción a pacientes y allegados que al resto de la población, pero no utilizan herramientas que les permitan una comunicación más fluida. Discusión y Conclusiones: Los resultados muestran la necesidad de contar con personal especializado y con espacios habilitados en la red para comunicarse con el resto de la población.

Long time remodeling during retinal degeneration evaluated by optical coherence tomography, immunocytochemistry and fundus autofluorescence

Purpose: To characterize the relationship between fundus autofluorescence (FAF), Optical Coherence Tomography (OCT) and immunohistochemistry (IHC) over the course of chronic retinal degeneration in the P23H rat. Methods: Homozygous albino P23H rats, Sprague–Dawley (SD) rats as controls and pigmented Long Evans (LE) rats were used. A Spectralis HRA OCT system was used for scanning laser ophthalmoscopy (SLO) imaging OCT and angiography. To determine FAF, fluorescence was excited using diode laser at 488 nm. A fast retina map OCT was performed using the optic nerve as a landmark. IHC was performed to correlate with the findings of OCT and FAF changes. Results: During the course of retinal degeneration, the FAF pattern evolved from some spotting at 2 months old to a mosaic of hyperfluorescent dots in rats 6 months and older. Retinal thicknesses progressively diminished over the course of the disease. At later stages of degeneration, OCT documented changes in the retinal layers, however, IHC better identified the cell loss and remodeling changes. Angiography revealed attenuation of the retinal vascular plexus with time. Conclusion: We provide for the first time a detailed long-term analysis of the course of retinal degeneration in P23H rats using a combination of SLO and OCT imaging, angiography, FAF and IHC. Although, the application of noninvasive methods enables longitudinal studies and will decrease the number of animals needed for a study, IHC is still an essential tool to identify retinal changes at the cellular level.

Astrocytes and Müller Cell Alterations During Retinal Degeneration in a Transgenic Rat Model of Retinitis Pigmentosa

Purpose: Retinitis pigmentosa includes a group of progressive retinal degenerative diseases that affect the structure and function of photoreceptors. Secondarily to the loss of photoreceptors, there is a reduction in retinal vascularization, which seems to influence the cellular degenerative process. Retinal macroglial cells, astrocytes, and Müller cells provide support for retinal neurons and are fundamental for maintaining normal retinal function. The aim of this study was to investigate the evolution of macroglial changes during retinal degeneration in P23H rats. Methods: Homozygous P23H line-3 rats aged from P18 to 18 months were used to study the evolution of the disease, and SD rats were used as controls. Immunolabeling with antibodies against GFAP, vimentin, and transducin were used to visualize macroglial cells and cone photoreceptors. Results: In P23H rats, increased GFAP labeling in Müller cells was observed as an early indicator of retinal gliosis. At 4 and 12 months of age, the apical processes of Müller cells in P23H rats clustered in firework-like structures, which were associated with ring-like shaped areas of cone degeneration in the outer nuclear layer. These structures were not observed at 16 months of age. The number of astrocytes was higher in P23H rats than in the SD matched controls at 4 and 12 months of age, supporting the idea of astrocyte proliferation. As the disease progressed, astrocytes exhibited a deteriorated morphology and marked hypertrophy. The increase in the complexity of the astrocytic processes correlated with greater connexin 43 expression and higher density of connexin 43 immunoreactive puncta within the ganglion cell layer (GCL) of P23H vs. SD rat retinas. Conclusions: In the P23H rat model of retinitis pigmentosa, the loss of photoreceptors triggers major changes in the number and morphology of glial cells affecting the inner retina.

Metaestudio cualitativo sobre vivencias y gestión del cotidiano en adultos mayores que padecen enfermedades crónicas

Objetivo: Describir la experiencia cultural, interpersonal y personal de los adultos mayores con enfermedades crónicas e identificar las estrategias y redes de apoyo que utilizan en su entorno cotidiano para gestionar la enfermedad. Método: Se desarrolló un metaestudio tipo metaanálisis cualitativo. La estrategia metodológica constó de cuatro etapas: Búsqueda bibliográfica, Categorización de los estudios, Evaluación de la calidad metodológica y Análisis de resultados. Resultados: Se obtuvo una muestra bibliográfica de 22 estudios de naturaleza cualitativa. Los hallazgos se organizaron en 4 categorías: Compresión del padecimiento, Autogestión en el cotidiano, Percepción de los Servicios de Salud y Cotidiano del cuidador. Conclusiones: El esfuerzo de los adultos mayores por alcanzar un nuevo equilibrio social y personal se articula en las estrategias de autogestión que utilizan en su día a día para afrontar sus padecimientos. Las interrelaciones con los servicios de salud, familia y redes de apoyo son fundamentales para gestionar la cronicidad.