Focussing on Neutrophils for Evaluating In vitro and In vivo Inflammatory Activities of Nanoparticles

A tremendous interest to use nanomaterials for medical diagnosis and therapeutic purposes has increased in the past few years. Although a lot of investigations focus on the use of nanoparticles (NPs) for drug delivery in cancer therapies, there are several studies investigating the potential use of NPs as carriers to detect allergies or to alleviate inflammatory symptoms. However, although this represents a very interesting interest and a potential avenue to use nanodrug systems, there are some potential toxic risks. For example, cytotoxicity, oxidative stress, genotoxicity, and inflammation have been reported both in in vitro and in vivo models for testing NPs. In addition to medicine, a variety of other sectors, including electronics, cosmetics, aerospace, textile industries, and even in food, used NPs. Consequently, the probability of human exposure to NPs has risen, leading to the possibility that NPs may reach the blood circulation and interact with immune blood cells. Therefore, it is crucial to evaluate the risk that NPs represent to human health. In different studies using in vivo models of inflammation, especially those investigating airway NP exposure, an increased number of leukocytes, mainly neutrophils, in the lungs and bronchoalveolar lavages have been reported. In fact, neutrophil counts are used as biomarkers of inflammation. Despite this and knowing that neutrophils are key player cells in inflammation, it is intriguing that few nanotoxicology studies have focused on how NPs can directly alter the biology of these cells. However, an increasing amount of studies, including some from my laboratory, demonstrate that NPs can activate human neutrophils by different manners in vitro and can attract them or not in vivo. The focus of this review will be to cover this new area of research

Proposition d'indicateurs produit, processus, organisation pour assurer l'adéquation entre l'expression d'un besoin et les spécifications du produit.

Les décisions prises très tôt au cours du cycle de conception génèrent la majeure partie des coûts et influent sur les délais. L'utilisation de modèles de représentation permet aux experts métiers d'échanger les données pertinentes du projet mais, pour les responsables des projets, il n'est pas aisé de décider à partir de ces données très variées et souvent hétérogènes. La mise en place d'indicateurs a pour objectif d'aider les décideurs dans leurs choix. La particularité des indicateurs ici proposés, est de prendre en compte des aspects qui ne sont pas seulement techniques (liés au produit). Les aspects processus et organisation sont considérés afin de prendre le projet dans toute sa complexité. L'utilisation de tels indicateurs permet au final d'obtenir un produit respectant l'expression du besoin et assurant la pérennité de l'entreprise

The Inflammatory Process in Response to Nanoparticles

products are already available on the market [1, 2]. The use of nanoparticles (NPs) has increased in the past few years in various fields including defence, aerospace, electronics, biology, and medicine. Therefore as human exposure to NPs increases, so do investigations on their toxicity. In one hand, nanotoxicology can be seen as an important subdiscipline of toxicology, and, on the other hand, it also represents a subdiscipline of nanotechnology [3]. Studies show that many parameters such as the diameter, surface area, surface composition, and solubility, to name a few, can all have an effect on cell responses, cellular interactions, and reactive oxygen species (ROS) production. They can also have an effect on NP capacity to bind to certain proteins or receptors. More importantly these parameters and others have also the potential to influence an inflammatory response following NP exposure as it has been shown in many in vitro and in vivo studies [4–7]. It has often been demonstrated that smaller particles tend to induce greater inflammatory responses than their bigger counterparts of same chemical composition [5]. Although some NPs may possess proinflammatory activities, the use of others and NP techniques can be very useful in medicine; for example, they can be used for drug-delivery therapies and may also represent excellent biomarkers for the diagnosis of diverse diseases, including inflammatory diseases. In an effort to increase our general knowledge regarding the inflammatory properties of NPs, thi

Activation of Neutrophils by Nanoparticles

The use of nanoparticles (NPs) has increased in the past few years in various fields, including defence, aerospace, electronics, biology, medicine, and so forth. and in applications such as diagnostic technology, bioimaging, and drug/gene delivery. Thus, human exposure to NPs and nanomaterials is unavoidable and will certainly expand in the future resulting in a growing interest in nanotoxicology, the study of toxicity of nanomaterials. A number of studies have reported the effects of NPs in respect to pulmonary inflammation by investigating in vitro activation of pulmonary cells with NPs and in vivo in a variety of models in which neutrophils appear to be the predominant leukocyte cell type in lungs and in bronchoalveolar lavages following inhalation or intratracheal instillation of NPs. Despite the fact that several studies have reported an increased number of neutrophils, the literature dealing with the direct activation of neutrophils by a given NP is poorly documented. This paper will summarize the current literature in this latter area of research and will end with a perspective view in which our laboratory will be involved in the following years

Global Sensitivity Analysis: a tool to analyse LCA variability of energy systems

International audiencePolicy makers are nowadays debating about the future electricity mixes that should be deployed. The environmental impacts of electricity generation systems is one of the central issue for this debate. They have been widely assessed over the past decades, in particular with the LCA approach. Several literature reviews have shown the large variability associated with these results. It leads sometimes policy makers to consider LCA as an inconclusive method. Improving the understanding of the LCA results variability origins is a key issue to extend the use of LCA as a decision support tool. One approach to adress variability are sensitivity analysis (SA). However, when dealing with environmental impact assessment, most SAs remain at a local level or evaluate the variation of the input parameters one factor at a time. These approaches only partially reflect the LCA results variability, indeed, it does not consider the full range of input parameters interval and their probability distribution. To overcome these limitations, Global Sensitivity Analysis (GSA) approach has been developped in statistics. It enables apportioning the results variability of a model to its different input parameter variability, by varying all of them simultaneously according to their probability distributions. This link between result variability and parameter variability is quantitatively evaluated by the calculation of the so called Sobol indices. While it has been applied in only a few analyses in the field of environmental impact assessment, this statistical tool is yet to be embedded in LCA methodology. Thereby, this paper aims at proposing a method to implement GSA in the LCA field to adress the results variability issue related to energy pathways

Robustness of the BYM model in absence of spatial variation in the residuals

<p>Abstract</p> <p>Background</p> <p>In the context of ecological studies, the Bayesian hierarchical Poisson model is of prime interest when studying the association between environmental exposure and rare diseases. However, adding spatially structured extra-variability in the model fitted to the data when such extra-variability does not exist conditionally on the covariates included in the model (<it>over-fitting</it>) may bias the estimation of the ecological association between covariates and relative risks toward the null. In order to investigate that possibility, a simulation study of the impact of introducing unnecessary residual spatial structure in the estimation model was conducted.</p> <p>Results</p> <p>In the case where no underlying extra-variability from the Poisson process exists, the simulation results show that models accounting for structured and unstructured residuals do not underestimate the ecological association, unless covariates have a very strong autocorrelation structure, i.e., 0.98 at 100 km on a territory of diameter 1000 km."</p