117 research outputs found

    Cholesterol-loaded nanoparticles ameliorate synaptic and cognitive function in Huntington's disease mice

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    Brain cholesterol biosynthesis and cholesterol levels are reduced in mouse models of Huntington's disease (HD), suggesting that locally synthesized, newly formed cholesterol is less available to neurons. This may be detrimental for neuronal function, especially given that locally synthesized cholesterol is implicated in synapse integrity and remodeling. Here, we used biodegradable and biocompatible polymeric nanoparticles (NPs) modified with glycopeptides (g7) and loaded with cholesterol (g7-NPs-Chol), which per se is not blood-brain barrier (BBB) permeable, to obtain high-rate cholesterol delivery into the brain after intraperitoneal injection in HD mice. We report that g7-NPs, in contrast to unmodified NPs, efficiently crossed the BBB and localized in glial and neuronal cells in different brain regions. We also found that repeated systemic delivery of g7-NPs-Chol rescued synaptic and cognitive dysfunction and partially improved global activity in HD mice. These results demonstrate that cholesterol supplementation to the HD brain reverses functional alterations associated with HD and highlight the potential of this new drug-administration route to the diseased brain

    High-Density Expression of Ca2+-Permeable ASIC1a Channels in NG2 Glia of Rat Hippocampus

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    NG2 cells, a fourth type of glial cell in the mammalian CNS, undergo reactive changes in response to a wide variety of brain insults. Recent studies have demonstrated that neuronally expressed acid-sensing ion channels (ASICs) are implicated in various neurological disorders including brain ischemia and seizures. Acidosis is a common feature of acute neurological conditions. It is postulated that a drop in pH may be the link between the pathological process and activation of NG2 cells. Such postulate immediately prompts the following questions: Do NG2 cells express ASICs? If so, what are their functional properties and subunit composition? Here, using a combination of electrophysiology, Ca2+ imaging and immunocytochemistry, we present evidence to demonstrate that NG2 cells of the rat hippocampus express high density of Ca2+-permeable ASIC1a channels compared with several types of hippocampal neurons. First, nucleated patch recordings from NG2 cells revealed high density of proton-activated currents. The magnitude of proton-activated current was pH dependent, with a pH for half-maximal activation of 6.3. Second, the current-voltage relationship showed a reversal close to the equilibrium potential for Na+. Third, psalmotoxin 1, a blocker specific for the ASIC1a channel, largely inhibited proton-activated currents. Fourth, Ca2+ imaging showed that activation of proton-activated channels led to an increase of [Ca2+]i. Finally, immunocytochemistry showed co-localization of ASIC1a and NG2 proteins in the hippocampus. Thus the acid chemosensor, the ASIC1a channel, may serve for inducing membrane depolarization and Ca2+ influx, thereby playing a crucial role in the NG2 cell response to injury following ischemia

    Early Birds in Day Care: The Social Gradient in Starting Day Care and Children's Non-Cognitive Skills

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    In recent years, almost all children below school age in Western industrialized countries have some experience of attending day care institutions. However, the age at which children enter day care and therefore the overall time spent in day carevaries substantially. We investigate the potential impact of later day care entry on the social and emotional behaviour of children, one important aspect of non-cognitive skills. Based on the English sample of the Millennium Cohort Study, we analyse the effects on children's development at the age of five and seven, using propensity score techniques. We find clear evidence of effects on children's development at the age of seven: Later day care entry increases children's peer-problems and reduces prosocial behaviour. We find that boys with low educated mothers and from families with a household income below the poverty line are most strongly affected

    REST Controls Self-Renewal and Tumorigenic Competence of Human Glioblastoma Cells

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    The Repressor Element 1 Silencing Transcription factor (REST/NRSF) is a master repressor of neuronal programs in non-neuronal lineages shown to function as a central regulator of developmental programs and stem cell physiology. Aberrant REST function has been associated with a number of pathological conditions. In cancer biology, REST has been shown to play a tumor suppressor activity in epithelial cancers but an oncogenic role in brain childhood malignancies such as neuroblastoma and medulloblastoma. Here we examined REST expression in human glioblastoma multiforme (GBM) specimens and its role in GBM cells carrying self-renewal and tumorigenic competence. We found REST to be expressed in GBM specimens, its presence being particularly enriched in tumor cells in the perivascular compartment. Significantly, REST is highly expressed in self-renewing tumorigenic-competent GBM cells and its knock down strongly reduces their self-renewal in vitro and tumor-initiating capacity in vivo and affects levels of miR-124 and its downstream targets. These results indicate that REST contributes to GBM maintenance by affecting its self-renewing and tumorigenic cellular component and that, hence, a better understanding of these circuitries in these cells might lead to new exploitable therapeutic targets

    Impacts of 1.5°C Global Warming on Natural and Human Systems

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    An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate povert

    Recommendations on basic requirements for intensive care units: structural and organizational aspects

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    OBJECTIVE: To provide guidance and recommendations for the planning or renovation of intensive care units (ICUs) with respect to the specific characteristics relevant to organizational and structural aspects of intensive care medicine. METHODOLOGY: The Working Group on Quality Improvement (WGQI) of the European Society of Intensive Care Medicine (ESICM) identified the basic requirements for ICUs by a comprehensive literature search and an iterative process with several rounds of consensus finding with the participation of 47 intensive care physicians from 23 countries. The starting point of this process was an ESICM recommendation published in 1997 with the need for an updated version. RESULTS: The document consists of operational guidelines and design recommendations for ICUs. In the first part it covers the definition and objectives of an ICU, functional criteria, activity criteria, and the management of equipment. The second part deals with recommendations with respect to the planning process, floorplan and connections, accommodation, fire safety, central services, and the necessary communication systems. CONCLUSION: This document provides a detailed framework for the planning or renovation of ICUs based on a multinational consensus within the ESIC

    Mothers' Labour Market Participation: Do Grandparents Make it Easier?

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    Childcare arrangements are key in women's ability to juggle motherhood and working outside the home. As such, the study of the access to childcare and its use is of great policy relevance. We focus on a particular kind of informal childcare, the one provided by grandparents. Empirically, assessing the effect of grandparental childcare is not an easy task due to unobserved preferences. In light of the potential outcome framework, we interpret the biases resulting from unobserved preferences as arising from the non-compliance of mothers to the availability of grandparents and from preferences of grandparents for activities other than childcare. Using an Instrumental Variable approach on Italian data, we find that the effect of grandparental childcare on mothers' labour supply is positive, statistically significant and economically relevant. The effect is stronger for lower educated mothers, with young children and living in the North and Centre
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