Abnormal Capillary Vasodynamics Contribute to Ictal Neurodegeneration in Epilepsy

Seizure-driven brain damage in epilepsy accumulates over time, especially in the hippocampus, which can lead to sclerosis, cognitive decline, and death. Excitotoxicity is the prevalent model to explain ictal neurodegeneration. Current labeling technologies cannot distinguish between excitotoxicity and hypoxia, however, because they share common molecular mechanisms. This leaves open the possibility that undetected ischemic hypoxia, due to ictal blood flow restriction, could contribute to neurodegeneration previously ascribed to excitotoxicity. We tested this possibility with Confocal Laser Endomicroscopy (CLE) and novel stereological analyses in several models of epileptic mice. We found a higher number and magnitude of NG2+ mural-cell mediated capillary constrictions in the hippocampus of epileptic mice than in that of normal mice, in addition to spatial coupling between capillary constrictions and oxidative stressed neurons and neurodegeneration. These results reveal a role for hypoxia driven by capillary blood flow restriction in ictal neurodegeneration

Abnormal Capillary Vasodynamics Contribute to Ictal Neurodegeneration in Epilepsy

Seizure-driven brain damage in epilepsy accumulates over time, especially in the hippocampus, which can lead to sclerosis, cognitive decline, and death. Excitotoxicity is the prevalent model to explain ictal neurodegeneration. Current labeling technologies cannot distinguish between excitotoxicity and hypoxia, however, because they share common molecular mechanisms. This leaves open the possibility that undetected ischemic hypoxia, due to ictal blood flow restriction, could contribute to neurodegeneration previously ascribed to excitotoxicity. We tested this possibility with Confocal Laser Endomicroscopy (CLE) and novel stereological analyses in several models of epileptic mice. We found a higher number and magnitude of NG2+ mural-cell mediated capillary constrictions in the hippocampus of epileptic mice than in that of normal mice, in addition to spatial coupling between capillary constrictions and oxidative stressed neurons and neurodegeneration. These results reveal a role for hypoxia driven by capillary blood flow restriction in ictal neurodegeneration

Determinants of Refusal of A/H1N1 Pandemic Vaccination in a High Risk Population: A Qualitative Approach

International audienceBackground: Our study analyses the main determinants of refusal or acceptance of the 2009 A/H1N1 vaccine in patients with cystic fibrosis, a high-risk population for severe flu infection, usually very compliant for seasonal flu vaccine.Methodology/Principal Findings: We conducted a qualitative study based on semi-structured interviews in 3 cystic fibrosis referral centres in Paris, France. The study included 42 patients with cystic fibrosis: 24 who refused the vaccine and 18 who were vaccinated. The two groups differed quite substantially in their perceptions of vaccine- and disease-related risks. Those who refused the vaccine were motivated mainly by the fears it aroused and did not explicitly consider the 2009 A/H1N1 flu a potentially severe disease. People who were vaccinated explained their choice, first and foremost, as intended to prevent the flu’s potential consequences on respiratory cystic fibrosis disease. Moreover, they considered vaccination to be an indirect collective prevention tool. Patients who refused the vaccine mentioned multiple, contradictory information sources and did not appear to consider the recommendation of their local health care provider as predominant. On the contrary, those who were vaccinated stated that they had based their decision solely on the clear and unequivocal advice of their health care provider.Conclusions/Significance: These results of our survey led us to formulate three main recommendations for improving adhesion to new pandemic vaccines. (1) it appears necessary to reinforce patient education about the disease and its specific risks, but also general population information about community immunity. (2) it is essential to disseminate a clear and effective message about the safety of novel vaccines. (3) this message should be conveyed by local health care providers, who should be involved in implementing immunization

Processing Maps for the Hot Forming of Polycrystalline Metallic Materials Using the Garofalo Equation

Processing maps have been built for > 30 years to predict the stable conditions for metal forming at high temperatures and strain rates. These maps, which also include efficiency conditions, are based on the stability criterion of Ziegler–Prasad (Z–P) within the framework of the dynamical materials model (DMM). In the present work, this criterion is drastically modified by introducing a Garofalo equation in the expression of the dissipative co-content, J, maintaining its definition in the framework of the DMM. This modification applies to its derivative with respect to the strain rate and also to the definition of efficiency, η. This new parameter developed in this work, named rho, ρ, is different from the stability parameter, xi, ξ, of the Z–P criterion since it is based on different constitutive equations. Rho is based on a Garofalo equation and xi on a power law equation. Both are obtained from experimental data and give rise to different stability maps that can be applied to any polycrystalline metallic material. In this work, a well-documented Ti-10V-4.5Fe alloy has been chosen to contrast the differences and similarities between the two methods of characterizing the stability conditions. Special emphasis is given to the predictions for the optimum forming temperatures.The authors acknowledge the financial support of CICYT, Spain, under Program MAT2015-68919 (MINECO/FEDER)

Modelización del proceso de degradación de envases metálicos para bebida, en el suelo, en el agua y en la interacción agua-suelo

En este estudio se evalúa la contaminación metálica que se produce a lo largo del tiempo al depositar en el suelo hojalata y hoja de aluminio, procedentes de envases comerciales de bebidas. Con el fin de evaluar el efecto del proceso de fabricación, se ha investigado el comportamiento del acero F111 y de la aleación de aluminio 3003, frecuentemente utilizados en la elaboración de estos envases. Para el estudio, se propone un diseño experimental que simula la degradación medioambiental a lo largo del tiempo de este tipo de envases cuando se depositan de forma incontrolada en el suelo. Los indicadores analíticos se han obtenido determinando la concentración de los metales mayoritarios en tres medios: agua, agua en presencia de suelo, y absorción-adsorción en suelo. Se ha desarrollado una metodología analítica para la determinación de la concentración de los elementos contaminantes mediante Espectrometría de Emisión Atómica con fuente de excitación ICP (ICP-OES). El método ha sido validado utilizando Materiales de Referencia (CRMs) de metales en suelo y agua; la precisión obtenida varía de 5,39 a 5,86% y de 5,75 a 6,27%, respectivamente, dependiendo del elemento analizado. El estudio estadístico llevado a cabo ha consistido en un análisis descriptivo seguido de un análisis factorial (modelo lineal general). La cuantificación metálica en los tres medios muestra que el suelo tiene un gran efecto inhibidor en la solubilidad de estos metales en agua. El proceso de fabricación de los envases para ambos materiales reduce la cesión metálica al medio.Peer reviewe