373 resultados para CEREBRAL PROTECTION
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La monnaie a été étudiée par des économistes hétérodoxes, des sociologues et des historiens qui ont souligné ses rapports à l'ordre collectif, mais elle n'est que rarement analysée sous l'angle de la citoyenneté. Notre thèse propose une réflexion théorique sur quatre types de fonctions (politique, symbolique, socioéconomique et psychoaffective) qui permettent à la monnaie de jouer un rôle de médiation de la citoyenneté. A partir d'une perspective qui combine les apports de l'économie politique internationale et de l'école de la régulation, nous montrons que cette médiation ne mobilise pas seulement des mécanismes sociopolitiques nationaux, mais aussi des mécanismes internationaux qui rétroagissent sur la sphère domestique des États et affectent leur capacité à définir leur régime de citoyenneté. Cette relation est analysée dans le contexte de l'institutionnalisation du système monétaire international de Bretton Woods (1944) et du développement de la globalisation financière depuis les années 1970. Si la monnaie a été mise au service d'un principe de protection des droits sociaux des citoyens contre les pressions financières extérieures après la Seconde guerre mondiale, elle contribue aujourd'hui à l'ouverture de la sphère domestique des Etats aux flux de capitaux transnationaux et à la création d'un ordre politique et juridique favorable aux droits des investisseurs. Cette dynamique est impulsée par l'essor de nouveaux intermédiaires financiers (notamment les agences de notation et les investisseurs institutionnels) et l'émergence concomitante d'une nouvelle forme d'Etat légitimée à partir d'un discours politique néolibéral insistant sur la quête de compétitivité, la réduction de la protection sociale et la responsabilisation individuelle. Elle se traduit par la privatisation des régimes de retraite et le développement des politiques d'éducation financière qui incitent les citoyens à se comporter en « preneurs de risques » actifs et responsables, assurant eux-mêmes leur sécurité économique à travers le placement de leur épargne retraite sur les marchés financiers. Nous soulignons toutefois les difficultés institutionnelles, cognitives et socioéconomiques qui rendent cette transformation de la citoyenneté contradictoire et problématique. Money has been studied by heterodox economists, sociologists and historians who stressed its relationship to collective order. However, it has hardly been analysed from the viewpoint of its relationship to citizenship. We propose a theoretical account of four types of functions (political, symbolic, socioeconomic and psychoaffective) enabling money to operate as a mediation of citizenship. From a perspective that combines the contributions of international political economy and the regulation school, we show that this mediation mobilises not only national sociopolitical mechanisms, but also international mechanisms which feed back on the domestic sphere of states and affect their capacity to define their regime of citizenship. This relationship is analysed in the context of the institutionalisation of the international monetary system of Bretton Woods (1944) and the development of financial globalization since the 1970s. If money has served to protect the social rights of citizens against external financial pressures after the Second World War, today it contributes to the opening of the domestic sphere of states to transnational capital flows and to the creation of a political and legal order favorable to the rights of investors. This dynamic is driven by the rise of new financial intermediaries (in particular rating agencies and institutional investisors) and the simultaneous emergence of a new form of state legitimized from a neoliberal political discourse emphasizing the quest for competitiveness, reduced social protection and individual responsibilization. It results in the privatization of pension systems and the development of policies of financial education that encourage citizens to behave as active and responsible « risk takers », ensuring their own economic security through the investment of their savings retirement on financial markets. However, we emphasize the institutional, cognitive and socioeconomic difficulties that make this transformation of citizenship contradictory and problematic. - Money has been studied by heterodox economists, sociologists and historians who stressed its relationship to collective order. However, it has hardly been analysed from the viewpoint of its relationship to citizenship. We propose a theoretical account of four types of functions (political, symbolic, socioeconomic and psychoaffective) enabling money to operate as a mediation of citizenship. From a perspective that combines the contributions of international political economy and the regulation school, we show that this mediation mobilises not only national sociopolitical mechanisms, but also international mechanisms which feed back on the domestic sphere of states and affect their capacity to define their regime of citizenship. This relationship is analysed in the context of the institutionalisation of the international monetary system of Bretton Woods (1944) and the development of financial globalization since the 1970s. If money has served to protect the social rights of citizens against external financial pressures after the Second World War, today it contributes to the opening of the domestic sphere of states to transnational capital flows and to the creation of a political and legal order favorable to the rights of investors. This dynamic is driven by the rise of new financial intermediaries (in particular rating agencies and institutional investisors) and the simultaneous emergence of a new form of state legitimized from a neoliberal political discourse emphasizing the quest for competitiveness, reduced social protection and individual responsibilization. It results in the privatization of pension systems and the development of policies of financial education that encourage citizens to behave as active and responsible « risk takers », ensuring their own economic security through the investment of their savings retirement on financial markets. However, we emphasize the institutional, cognitive and socioeconomic difficulties that make this transformation of citizenship problematic.
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Introduction ICM+ software encapsulates our 20 years' experience in brain monitoring. It collects data from a variety of bedside monitors and produces time trends of parameters defi ned using confi gurable mathematical formulae. To date it is being used in nearly 40 clinical research centres worldwide. We present its application for continuous monitoring of cerebral autoregulation using near-infrared spectroscopy (NIRS). Methods Data from multiple bedside monitors are processed by ICM+ in real time using a large selection of signal processing methods. These include various time and frequency domain analysis functions as well as fully customisable digital fi lters. The fi nal results are displayed in a variety of ways including simple time trends, as well as time window based histograms, cross histograms, correlations, and so forth. All this allows complex information from bedside monitors to be summarized in a concise fashion and presented to medical and nursing staff in a simple way that alerts them to the development of various pathological processes. Results One hundred and fi fty patients monitored continuously with NIRS, arterial blood pressure (ABP) and intracranial pressure (ICP), where available, were included in this study. There were 40 severely headinjured adult patients, 27 SAH patients (NCCU, Cambridge); 60 patients undergoing cardiopulmonary bypass (John Hopkins Hospital, Baltimore) and 23 patients with sepsis (University Hospital, Basel). In addition, MCA fl ow velocity (FV) was monitored intermittently using transcranial Doppler. FV-derived and ICP-derived pressure reactivity indices (PRx, Mx), as well as NIRS-derived reactivity indices (Cox, Tox, Thx) were calculated and showed signifi cant correlation with each other in all cohorts. Errorbar charts showing reactivity index PRx versus CPP (optimal CPP chart) as well as similar curves for NIRS indices versus CPP and ABP were also demonstrated. Conclusions ICM+ software is proving to be a very useful tool for enhancing the battery of available means for monitoring cerebral vasoreactivity and potentially facilitating autoregulation guided therapy. Complexity of data analysis is also hidden inside loadable profi les, thus allowing investigators to take full advantage of validated protocols including advanced processing formulas.
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ABSTRACT: Excitotoxicity and cerebral ischemia induce strong endocytosis in neurons, and we here investigate its functional role in neuroprotection by a functional transactivator of transcription (TAT)-peptide, the c-Jun N-terminal kinase (JNK) inhibitor D-JNKI1, against NMDA-excitotoxicity in vitro and neonatal ischemic stroke in P12 Sprague-Dawley rats. In both situations, the neuroprotective efficacy of D-JNKI1 was confirmed, but excessively high doses were counterproductive. Importantly, the induced endocytosis was necessary for neuroprotection, which required that the TAT-peptide be administered at a time when induced endocytosis was occurring. Uptake by other routes failed to protect, and even promoted cell death at high doses. Blocking the induced endocytosis of D-JNKI1 with heparin or with an excess of D-TAT-peptide eliminated the neuroprotection. We conclude that excitotoxicity-induced endocytosis is a basic property of stressed neurons that can target neuroprotective TAT-peptides into the neurons that need protection. Furthermore, it is the main mediator of neuroprotection by D-JNKI1. This may explain promising reports of strong neuroprotection by TAT-peptides without apparent side effects, and warns that the timing of peptide administration is crucial.
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Rockfall is an extremely rapid process involving long travel distances. Due to these features, when an event occurs, the ability to take evasive action is practically zero and, thus, the risk of injury or loss of life is high. Damage to buildings and infrastructure is quite likely. In many cases, therefore, suitable protection measures are necessary. This contribution provides an overview of previous and current research on the main topics related to rockfall. It covers the onset of rockfall and runout modelling approaches, as well as hazard zoning and protection measures. It is the aim of this article to provide an in-depth knowledge base for researchers and practitioners involved in projects dealing with the rockfall protection of infrastructures, who may work in the fields of civil or environmental engineering, risk and safety, the earth and natural sciences.
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Mutations in the CACNA1A gene, encoding the α1 subunit of the voltage-gated calcium channel CaV2.1 (P/Q-type), have been associated with three neurological phenotypes: familial and sporadic hemiplegic migraine type 1 (FHM1, SHM1), episodic ataxia type 2 (EA2), and spinocerebellar ataxia type 6 (SCA6). We report a child with congenital ataxia, abnormal eye movements and developmental delay who presented severe attacks of hemiplegic migraine triggered by minor head traumas and associated with hemispheric swelling and seizures. Progressive cerebellar atrophy was also observed. Remission of the attacks was obtained with acetazolamide. A de novo 3bp deletion was found in heterozygosity causing loss of a phenylalanine residue at position 1502, in one of the critical transmembrane domains of the protein contributing to the inner part of the pore. We characterized the electrophysiology of this mutant in a Xenopus oocyte in vitro system and showed that it causes gain of function of the channel. The mutant CaV2.1 activates at lower voltage threshold than the wild type. These findings provide further evidence of this molecular mechanism as causative of FHM1 and expand the phenotypic spectrum of CACNA1A mutations with a child exhibiting severe SHM1 and non-episodic ataxia of congenital onset.
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Dissociated cerebral hemisphere cells from 4- to 7-day-old chick embryos were cultured either on a collagen or a polylysine substrate in a serum-containing medium. Neurons were characterized by the demonstration of acetylcholinesterase, the presence of D2/N-CAM glycoprotein and neurofilament proteins. The proliferation of neuronal precursor cells was shown by morphological observations, autoradiographic analysis and measurements of [3H]-thymidine incorporation. Neuronal precursors derived from the 6-day-old embryos showed the highest proliferative activity. Neuroblast proliferation was found to be dependent on the culture substrates (i.e. polylysine or collagen), which yielded either isolated cells or cell aggregates, and the latter favored the mitogenic effect.
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OBJECTIVE: To evaluate whether early mobilization after acute ischaemic stroke is better than delayed mobilization with regard to medical complications and if it is safe in relation to neurological function and cerebral blood flow. DESIGN: Randomized controlled pilot trial of early versus delayed mobilization out of bed with incidence of severe complications as the primary outcome. SETTING: Acute stroke unit in the neurology department of a University Hospital. PARTICIPANTS: Fifty patients after ischaemic stroke with a National Institutes of Health Stroke Scale (NIHSS) score >6 were recruited. INTERVENTION: All patients were treated with physiotherapy immediately after their admission. In the early protocol patients were mobilized out of bed after 52 hours, in the delayed protocol after seven days. RESULTS: Eight out of 50 randomized patients were excluded from the per-protocol analysis because of early transfer to other hospitals. There were 2 (8%) severe complications in the 25 early mobilization patients and 8 (47%) in the 17 delayed mobilization patients (P < 0.006). There were no differences in the total number of complications or in clinical outcome. In the 26 patients (62%) who underwent serial transcranial Doppler ultrasonography, no blood flow differences were found. CONCLUSION: We found an apparent reduction in severe complications and no increase in total complications with an early mobilization protocol after acute ischaemic stroke. No influence on neurological three-month outcomes or on cerebral blood flow was seen. These results justify larger trials comparing mobilization protocols with possibly even faster mobilization out of bed than explored here.
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France amended its constitution in 2005 to include a Charter for the Environment. The Charter lays out France's commitment to supporting the right to a 'balanced environment'. This article first traces the Charter's origins to a legacy-building presidential initiative. Jacques Chirac decided to invest in a neglected policy domain in which his own majority had shown little interest. He was obliged to intervene repeatedly in order to bring this project to a successful conclusion. In doing so, he staked out environmental affairs as an area of potential presidential supremacy. Next, the content of the Charter is examined. In this document, French traditions of universalism come together with an international movement for anticipatory environmental protection. This is reflected in the constitutionalisation of the precautionary principle, which emerged as the most controversial part of the Charter. The debates this provoked tended to caricature a risk-management principle whose meaning has been carefully refined to forestall objections. Finally, the Charter's potential efficacy is analysed. The post-Charter record of legislative and judicial activity concerning the environment is meagre, but not wholly inauspicious.
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[Table des matières] 1. Contexte, objet et modalités de traitement de la saisine ; Partie A : Exigences réglementaires, normatives et recensement des EPC-EPI amiante. - 2. Exigences réglementaires en matière de protection collective et individuelle contre l'amiante. - 3. Normes d'exigences pour les équipements de protection collective contre l'amiante. - 4. Aspirateurs à usage industriel. - 5. Norms d'exigences pour la protection individuelle contre l'amiante. - 6. Recensement des EPC et EPI en fonction des activités. - 7. Objectifs de la synthèse bibliographique. - 8. Rappels théoriques sur la filtration de l'air. - 9. Efficacité des équipements de protection collective contre l'amiante. - 10. Aspirateurs à usage industriel. - 11. Efficacité des équipements de protection individuelle. - 12. Comparaison de la filtration des fibres d'amiante ou autres particules non sphériques et des aérosols utilisés pour les essais normalisés (MPPS). - 13. Conclusion sur la synthèse bibliographique. - 14. Perspectives. - 15. Bibliographie. - Annexes
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OBJECTIVES: To analyze the effect of tight glycemic control with the use of intensive insulin therapy on cerebral glucose metabolism in patients with severe brain injury. DESIGN: Retrospective analysis of a prospective observational cohort. SETTING: University hospital neurologic intensive care unit. PATIENTS: Twenty patients (median age 59 yrs) monitored with cerebral microdialysis as part of their clinical care. INTERVENTIONS: Intensive insulin therapy (systemic glucose target: 4.4-6.7 mmol/L [80-120 mg/dL]). MEASUREMENTS AND MAIN RESULTS: Brain tissue markers of glucose metabolism (cerebral microdialysis glucose and lactate/pyruvate ratio) and systemic glucose were collected hourly. Systemic glucose levels were categorized as within the target "tight" (4.4-6.7 mmol/L [80-120 mg/dL]) vs. "intermediate" (6.8-10.0 mmol/L [121-180 mg/dL]) range. Brain energy crisis was defined as a cerebral microdialysis glucose <0.7 mmol/L with a lactate/pyruvate ratio >40. We analyzed 2131 cerebral microdialysis samples: tight systemic glucose levels were associated with a greater prevalence of low cerebral microdialysis glucose (65% vs. 36%, p < 0.01) and brain energy crisis (25% vs.17%, p < 0.01) than intermediate levels. Using multivariable analysis, and adjusting for intracranial pressure and cerebral perfusion pressure, systemic glucose concentration (adjusted odds ratio 1.23, 95% confidence interval [CI] 1.10-1.37, for each 1 mmol/L decrease, p < 0.001) and insulin dose (adjusted odds ratio 1.10, 95% CI 1.04-1.17, for each 1 U/hr increase, p = 0.02) independently predicted brain energy crisis. Cerebral microdialysis glucose was lower in nonsurvivors than in survivors (0.46 +/- 0.23 vs. 1.04 +/- 0.56 mmol/L, p < 0.05). Brain energy crisis was associated with increased mortality at hospital discharge (adjusted odds ratio 7.36, 95% CI 1.37-39.51, p = 0.02). CONCLUSIONS: In patients with severe brain injury, tight systemic glucose control is associated with reduced cerebral extracellular glucose availability and increased prevalence of brain energy crisis, which in turn correlates with increased mortality. Intensive insulin therapy may impair cerebral glucose metabolism after severe brain injury.