51 research outputs found

    LITIO COMO TERAPIA NEUROPROTECTORA EN EL MODELO APPSL/PS1M146L DE LA ENFERMEDAD DE ALZHEIMER

    Get PDF
    El litio se utiliza desde hace varias décadas en el tratamiento de trastornos bipolares y la depresión, y recientemente se debate su uso potencial en patologías neurodegenerativas como la enfermedad de Alzheimer (AD). Diversos estudios han puesto de manifiesto su efecto positivo como potente inhibidor de GSK3beta disminuyendo la fosforilación de tau, la producción de Abeta e incrementando plasticidad sináptica. Sin embargo, su posible efecto neuroprotector previniendo la muerte neuronal in vivo no ha sido aun demostrado ya que la mayoría de los modelos transgénicos de AD no presentan pérdida neuronal. Nuestro modelo APPSL/PS1M146L sufre una pérdida significativa de neuronas SOM/NPY en hipocampo y corteza entorrinal desde edades tempranas (6 meses) con un marcado desarrollo de distrofias axonales. En este trabajo hemos estudiado el posible efecto neuroprotector del litio en este modelo animal mediante tratamiento crónico en la dieta desde los 3 hasta los 9 meses de edad. Se han utilizado técnicas imnunohistoquímicas, western blots y análisis por RT-PCR, y además se ha determinado la carga amiloide, el grado de compactación y el tamaño de las placas. El resultado más relevante de este estudio fue la preservación de la población de interneuronas SOM/NPY tanto en hipocampo como corteza entorrinal en los animales tratados, mientras que en los no tratados existió una pérdida significativa de esta supoblación neuronal. El efecto neuroprotector del litio se manifestó también en una marcada disminución de tau fosforilado, distrofias axonales y marcadores sinápticos, junto con una mejora cognitiva de los animales utilizando el test de reconocimiento de objetos. Este efecto preventivo del litio parece estar asociado con cambios en la formación de placas de Abeta que podrían afectar a su toxicidad, ya que los animales tratados presentaron placas más pequeñas y apariencia más compacta. Financiación: FIS PI12/01431 (AG) y FIS PI12/01439 (JV).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Abnormal accumulation of autophagic vesicles correlates with axonal and synaptic pathology in young Alzheimer’s mice hippocampus

    Get PDF
    Dystrophic neurites associated with amyloid plaques precede neuronal death and manifest early in Alzheimer’s disease (AD). In this work we have characterized the plaque-associated neuritic pathology in the hippocampus of young (4- to 6-month-old) PS1M146L/APP751SL mice model, as the initial degenerative process underlying functional disturbance prior to neuronal loss. Neuritic plaques accounted for almost all fibrillar deposits and an axonal origin of the dystrophies was demonstrated. The early induction of autophagy pathology was evidenced by increased protein levels of the autophagosome marker LC3 that was localized in the axonal dystrophies, and by electron microscopic identification of numerous autophagic vesicles filling and causing the axonal swellings. Early neuritic cytoskeletal defects determined by the presence of phosphorylated tau (AT8-positive) and actin–cofilin rods along with decreased levels of kinesin-1 and dynein motor proteins could be responsible for this extensive vesicle accumulation within dystrophic neurites. Although microsomal Aβ oligomers were identified, the presence of A11-immunopositive Aβ plaques also suggested a direct role of plaque-associated Aβ oligomers in defective axonal transport and disease progression. Most importantly, presynaptic terminals morphologically disrupted by abnormal autophagic vesicle buildup were identified ultrastructurally and further supported by synaptosome isolation. Finally, these early abnormalities in axonal and presynaptic structures might represent the morphological substrate of hippocampal dysfunction preceding synaptic and neuronal loss and could significantly contribute to AD pathology in the preclinical stages

    The effect of autonomy, training opportunities, age and salaries on job satisfaction in the South East Asian retail petroleum industry

    Get PDF
    South East Asian petroleum retailers are under considerable pressure to improve service quality by reducing turnover. An empirical methodology from this industry determined the extent to which job characteristics, training opportunities, age and salary influenced the level of job satisfaction, an indicator of turnover. Responses are reported on a random sample of 165 site employees (a 68% response rate) of a Singaporean retail petroleum firm. A restricted multivariate regression model of autonomy and training opportunities explained the majority (35.4%) of the variability of job satisfaction. Age did not moderate these relationships, except for employees >21 years of age, who reported enhanced job satisfaction with additional salary. Human Capital theory, Life Cycle theory and Job Enrichment theory are invoked and explored in the context of these findings in the South East Asian retail petroleum industry. In the South East Asian retail petroleum industry, jobs providing employees with the opportunity to undertake a variety of tasks that enhanced the experienced meaningfulness of work are likely to promote job satisfaction, reduce turnover and increase the quality of service

    Neonicotinoid Insecticides and Their Impacts on Bees: A Systematic Review of Research Approaches and Identification of Knowledge Gaps

    Get PDF
    It has been suggested that the widespread use of neonicotinoid insecticides threatens bees, but research on this topic has been surrounded by controversy. In order to synthesize which research approaches have been used to examine the effect of neonicotinoids on bees and to identify knowledge gaps, we systematically reviewed research on this subject that was available on the Web of Science and PubMed in June 2015. Most of the 216 primary research studies were conducted in Europe or North America (82%), involved the neonicotinoid imidacloprid (78%), and concerned the western honey bee Apis mellifera (75%). Thus, little seems to be known about neonicotinoids and bees in areas outside Europe and North America. Furthermore, because there is considerable variation in ecological traits among bee taxa, studies on honey bees are not likely to fully predict impacts of neonicotinoids on other species. Studies on crops were dominated by seed-treated maize, oilseed rape (canola) and sunflower, whereas less is known about potential side effects on bees from the use of other application methods on insect pollinated fruit and vegetable crops, or on lawns and ornamental plants. Laboratory approaches were most common, and we suggest that their capability to infer real-world consequences are improved when combined with information from field studies about realistic exposures to neonicotinoids. Studies using field approaches often examined only bee exposure to neonicotinoids and more field studies are needed that measure impacts of exposure. Most studies measured effects on individual bees. We suggest that effects on the individual bee should be linked to both mechanisms at the sub-individual level and also to the consequences for the colony and wider bee populations. As bees are increasingly facing multiple interacting pressures future research needs to clarify the role of neonicotinoids in relative to other drivers of bee declines

    Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

    Get PDF
    Contains fulltext : 172380.pdf (publisher's version ) (Open Access

    Measurements of photo-nuclear jet production in Pb plus Pb collisions with ATLAS

    Get PDF
    Ultra-peripheral heavy ion collisions provide a unique opportunity to study the parton distributions in the colliding nuclei via the measurement of photo-nuclear jet production. An analysis of jet production in ultra-peripheral Pb+Pb collisions at √sNN = 5.02 TeV performed using data collected with the ATLAS detector in 2015 is described. The data set corresponds to a total Pb+Pb integrated luminosity of 0.38 nb−1. The ultra-peripheral collisions are selected using a combination of forward neutron and rapidity gap requirements. The cross-sections, not unfolded for detector response, are compared to results from Pythia Monte Carlo simulations re-weighted to match a photon spectrum obtained from the STARlight model. Qualitative agreement between data and these simulations is observed over a broad kinematic range suggesting that using these collisions to measure nuclear parton distributions is experimentally realisable

    Crosstalk Between Macroautophagy and Chaperone-Mediated Autophagy: Implications for the Treatment of Neurological Diseases

    Get PDF

    Measurements of photo-nuclear jet production in Pb + Pb collisions with ATLAS

    Get PDF
    Ultra-peripheral heavy ion collisions provide a unique opportunity to study the parton distributions in the colliding nuclei via the measurement of photo-nuclear jet production. An analysis of jet production in ultra-peripheral Pb+Pb collisions at √sNN = 5.02 TeV performed using data collected with the ATLAS detector in 2015 is described. The data set corresponds to a total Pb+Pb integrated luminosity of 0.38 nb⁻¹. The ultra-peripheral collisions are selected using a combination of forward neutron and rapidity gap requirements. The cross-sections, not unfolded for detector response, are compared to results from Pythia Monte Carlo simulations re-weighted to match a photon spectrum obtained from the STARlight model. Qualitative agreement between data and these simulations is observed over a broad kinematic range suggesting that using these collisions to measure nuclear parton distributions is experimentally realisable
    corecore