Phosphorylated α-synuclein-immunoreactive retinal neuronal elements in Parkinson's disease subjects

Visual symptoms are relatively common in Parkinson's disease (PD) and optical coherence tomography has indicated possible retinal thinning. Accumulation of aggregated α-synuclein is thought to be a central pathogenic event in the PD brain but there have not as yet been reports of retinal synucleinopathy. Retinal wholemounts were prepared from subjects with a primary clinicopathological diagnosis of PD (N = 9), dementia with Lewy bodies (DLB; N = 3), Alzheimer's disease (N = 3), progressive supranuclear palsy (N = 2) as well as elderly normal control subjects (N = 4). These were immunohistochemically stained with an antibody against α-synuclein phosphorylated at serine 129, which is a specific molecular marker of synucleinopathy. Phosphorylated α-synuclein-immunoreactive (p-syn IR) nerve fibers were present in 7/9 PD subjects and in 1/3 DLB subjects; these were sparsely distributed and superficially located near or at the inner retinal surface. The fibers were either long and straight or branching, often with multiple en-passant varicosities along their length. The straight fibers most often had an orientation that was radial with respect to the optic disk. Together, these features are suggestive of either retinopetal/centrifugal fibers or of ganglion cell axons. In one PD subject there were sparse p-syn IR neuronal cell bodies with dendritic morphology suggestive of G19 retinal ganglion cells or intrinsically photosensitive ganglion cells. There were no stained nerve fibers or other specific staining in any of the non-PD or non-DLB subjects. It is possible that at least some of the observed visual function impairments in PD subjects might be due to α-synucleinopathy.

Loss of Outer Retinal Neurons and Circuitry Alterations in the DBA/2J Mouse

Purpose. The DBA/2J mouse line develops essential iris atrophy, pigment dispersion, and glaucomatous age-related changes, including an increase of IOP, optic nerve atrophy, and retinal ganglion cell (RGC) death. The aim of this study was to evaluate possible morphological changes in the outer retina of the DBA/2J mouse concomitant with disease progression and aging, based on the reduction of both the a- and b-waves and photopic flicker ERGs in this mouse line. Methods. Vertically sectioned DBA/2J mice retinas were evaluated at 3, 8, and 16 months of age using photoreceptor, horizontal, and bipolar cell markers. Sixteen-month-old C57BL/6 mice retinas were used as controls. Results. The DBA/2J mice had outer retinal degeneration at all ages, with the most severe degeneration in the oldest retinas. At 3 months of age, the number of photoreceptor cells and the thickness of the OPL were reduced. In addition, there was a loss of horizontal and ON-bipolar cell processes. At 8 months of age, RGC degeneration occurred in patches, and in the outer retina overlying these patches, cone morphology was impaired with a reduction in size as well as loss of outer segments and growth of horizontal and bipolar cell processes into the outer nuclear layer. At 16 months of age, connectivity between photoreceptors and horizontal and bipolar cell processes overlying these patches was lost. Conclusions. Retinal degeneration in DBA/2J mice includes photoreceptor death, loss of bipolar and horizontal cell processes, and loss of synaptic contacts in an aging-dependent manner.

Salud y condiciones de trabajo en trabajadores mayores

Introducción: En los últimos años, la población española ha experimentado un crecimiento acelerado de personas mayores. Las previsiones demográficas a corto-medio plazo describen un importante predominio de trabajadores mayores en el mercado laboral. Objetivos: Identificar las diferencias según dos grupos de edad (<55 años y ≥55 años) en la percepción de las condiciones de trabajo y salud de la población trabajadora española. Metodología: Las diferencias entre los dos grupos de edad se analizaron a partir de indicadores de condiciones de trabajo y de salud pertenecientes a la VII Encuesta Nacional de Condiciones de Trabajo del Instituto de Seguridad e Higiene en el Trabajo (VII_ENCT). El análisis consistió en el cálculo de las prevalencias y la odds ratio cruda-ORc y ajustada por sexo con su correspondiente intervalo del confianza al 95% Resultados: El grupo de trabajadores más jóvenes presentan más riesgo de exposición a seis de los siete indicadores relacionados con las condiciones de trabajo (ruido, vibraciones, carga física, carga mental, autonomía y motivación). No obstante los trabajadores mayores tienen una peor percepción de su estado de salud (ORa= 2,06 [1,75-2,42]) y presentan en mayor medida problemas de salud que si bien les conducen a la visita médica más frecuentemente los relacionan menos con su actividad laboral. Conclusiones: A tenor de los resultados, los trabajadores de 55 años y más refieren tener menos quejas respecto a sus condiciones laborales e incluso se sienten más autónomos y motivados. Es el deterioro físico y mental la principal limitación que encuentran estos trabajadores a la hora de ejercer sus tareas. Sería recomendable establecer políticas de promoción de la salud dentro de las empresas para mejorar los indicadores de salud y promover el envejecimiento activo de la población trabajadora española.