410 research outputs found

    Inhibition of PMCA activity by tau as a function of aging and Alzheimer's neuropathology

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    © 2015 Elsevier B.V.. Ca2+-ATPases are plasma membrane and intracellular membrane transporters that use the energy of ATP hydrolysis to pump cytosolic Ca2+ out of the cell (PMCA) or into internal stores. These pumps are the main high-affinity Ca2+ systems involved in the maintenance of intracellular free Ca2+ at the properly low level in eukaryotic cells. The failure of neurons to keep optimal intracellular Ca2+ concentrations is a common feature of neurodegeneration by aging and aging-linked neuropathologies, such as Alzheimer's disease (AD). This disease is characterized by the accumulation of β-amyloid senile plaques and neurofibrillary tangles of tau, a protein that plays a key role in axonal transport. Here we show a novel inhibition of PMCA activity by tau which is concentration-dependent. The extent of inhibition significantly decreases with aging in mice and control human brain membranes, but inhibition profiles were similar in AD-affected brain membrane preparations, independently of age. No significant changes in PMCA expression and localization with aging or neuropathology were found. These results point out a link between Ca2+-transporters, aging and neurodegeneration mediated by tau protein.Ministerio de Economía y Competitividad and Fundación Marcelino Botín (to A.M.M.); Junta de Extremadura and FEDERPeer Reviewe

    Absorption and cutaneous deposition of yellow pigment in male and female broilers in response to different levels of xanthophylls from Tagetes erecta

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    To determine the saturation point of absorption and cutaneous deposition of yellow xanthophylls (XA) in broilers, two hundred and sixteen Ross 308 chickens (108 males and 108 females) were sorted by sex and randomly assigned to 6 dietary treatments containing 6 replications of 6 birds each. Treatments consisted of increasing levels of xanthophylls from Aztec marigold flower (Tagetes erecta) (65, 92, 119, 146, 173, and 200 ppm). Weight gain, feed consumption, and feed conversion were measuredweekly. Plasma pigment levels and skin yellowness in live birds were measured twice per week. Growth performance was analysed through ANOVA for a 6X2 factorial arrangement, where the first factor was the XA adding at six levels, and the second factor was sex at two levels. Pigment plasma concentration and skin yellowness were fitted into a multiple linear regression model. Results indicated that the highest levels of plasma xanthophylls and skin yellowness were found after 28 d of feeding. Skin yellowness increased by 2.24 b* for every d of xanthophylls consumption. In the females, skin yellowness was 1.35 b* higher than in the males. Increasing dietary xanthophylls by 10 ppm was reflected in 0.83 b* of increase in skin yellowness

    Experience of parents who have suffered a perinatal death in two Spanish hospitals: a qualitative study

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    Background: Perinatal grief is a process that affects families in biological, psychological, social and spiritual terms. It is estimated that every year there are 2.7 million perinatal deaths worldwide and 4.43 deaths for every 1000 births in Spain. The aim of this study is to describe and understand the experiences and perceptions of parents who have suffered a perinatal death. Methods: A qualitative study based on Gadamer’s hermeneutic phenomenology. The study was conducted in two hospitals in the South of Spain. Thirteen mothers and eight fathers who had suffered a perinatal death in the 5 years prior to the study participated in this study. In-depth interviews were carried out for data collection. Inductive analysis was used to find themes based on the data. Results: Eight sub-themes emerged, and they were grouped into three main themes: ‘Perceiving the threat and anticipating the baby’s death: “Something is going wrong in my pregnancy”’; ‘Emotional outpouring: the shock of losing a baby and the pain of giving birth to a stillborn baby’; “We have had a baby”: The need to give an identity to the baby and legitimise grief’. Conclusion: The grief suffered after a perinatal death begins with the anticipation of the death, which relates to the mother’s medical history, symptoms and premonitions. The confirmation of the death leads to emotional shock, characterised by pain and suffering. The chance to take part in mourning rituals and give the baby the identity of a deceased baby may help in the grieving and bereavement process. Having empathy for the parents and notifying them of the death straightaway can help ease the pain. Midwives can help in the grieving process by facilitating the farewell rituals, accompanying the family, helping in honouring the memory of the baby, and supporting parents in giving the deceased infant an identity that makes them a family member

    Left-handed musicians show a higher probability of atypical cerebral dominance for language

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    Music processing and right hemispheric language lateralization share a common network in the right auditory cortex and its frontal connections. Given that the development of hemispheric language dominance takes place over several years, this study tested whether musicianship could increase the probability of observing right language dominance in left-handers. Using a classic fMRI language paradigm, results showed that atypical lateralization was more predominant in musicians (40%) than in nonmusicians (5%). Comparison of left-handers with typical left and atypical right lateralization revealed that: (a) atypical cases presented a thicker right pars triangularis and more gyrified left Heschl's gyrus; and (b) the right pars triangularis of atypical cases showed a stronger intra-hemispheric functional connectivity with the right angular gyrus, but a weaker interhemispheric functional connectivity with part of the left Broca's area. Thus, musicianship is the first known factor related to a higher prevalence of atypical language dominance in healthy left-handed individuals. We suggest that differences in the frontal and temporal cortex might act as shared predisposing factors to both musicianship and atypical language lateralization

    Estimación de la Incertidumbre de medida en ensayos por Espectrometría de Emisión Óptica en aceros al carbono y de baja aleación

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    Los laboratorios que introducen mediciones para el control de la calidad o aspiran a la acreditación de métodos de ensayo enfrentan el problema de la estimación de la Incertidumbre de medida. En este trabajo se presenta la estimación de la incertidumbre de medida en ensayos por Espectrometría de Emisión Óptica en el Laboratorio Instrumental de ACINOX Las Tunas, a través del enfoque GUM. Se identificaron como principales fuentes, las variaciones por vaporización y excitación y la obtención de la imagen óptica. Se determinó la tendencia de variación de la incertidumbre con la concentración y la necesidad de reportarla asociada al nivel de concentración del analito. La aplicaciónde este procedimiento reduce el costo respecto a métodos aplicados anteriormente y permite un enfoque unificado para el estudio de la importancia relativa de cada una de las contribuciones. Los estimados de incertidumbre se verificaron mediante ensayos a un Material de Referencia Certificado
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