17 research outputs found

    Quels sont les facteurs influençant le nombre optimal d'allégations dans les publicités de produits alimentaires?

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    Objectif : L’objectif de cet article est d’analyser l’impact du nombre d’allĂ©gations dans les publicitĂ©s sur la qualitĂ© perçue et le rĂŽle modĂ©rateur du type d’allĂ©gations dans cette relation. Design/mĂ©thodologie/approche : Un questionnaire en ligne a Ă©tĂ© rĂ©pondu par 761 consommateurs Ă  l’aide d’un panel. Dans le but de rĂ©pondre Ă  l’objectif de la recherche, cette Ă©tude a adoptĂ© un design de 4 (Nombre d’allĂ©gations: 1, 2, 3 ou 4) X 2 (Type d’allĂ©gations: identique ou diffĂ©rent) X 2 (Certification biologique: avec ou sans logo). RĂ©sultats : D’abord, lorsque des allĂ©gations de type diffĂ©rent sont incluses dans une publicitĂ©, il est prĂ©fĂ©rable d’ajouter quatre allĂ©gations. À l’inverse, lorsque des allĂ©gations de mĂȘme type sont prĂ©sentes dans une communication, il est prĂ©fĂ©rable d’ajouter moins de trois allĂ©gations. De plus, le nombre d’allĂ©gations impact directement la charge cognitive perçue qui elle a un impact sur la qualitĂ© perçue d’un produit. Finalement, un effet d’interaction s’est montrĂ© significatif entre la redondance perçue et le type d’allĂ©gation impactant la charge cognitive. En effet, l’effet de la redondance perçue sur la charge cognitive est plus fort avec des allĂ©gations de type diffĂ©rent. Limites/implications de la recherche : Cette Ă©tude ayant traitĂ© du secteur de l’alimentation avec un Ă©chantillon reprĂ©sentatif de la population quĂ©bĂ©coise est non gĂ©nĂ©ralisable sur plusieurs secteurs d’activitĂ© et sur plusieurs marchĂ©s. De plus, puisque les rĂ©pondants devaient analyser la publicitĂ© de maniĂšre autonome en ligne, l’attention rĂ©elle portĂ©e Ă  l’égard de ces derniĂšres n’a pu ĂȘtre contrĂŽlĂ©e. OriginalitĂ© : En plus de n’avoir aucun consensus dans la littĂ©rature en ce qui a trait au nombre optimal d’allĂ©gations dans les publicitĂ©s, nul ne s’est intĂ©ressĂ© Ă  l’identification des facteurs qui permettent de rĂ©duire en deçà de trois le nombre d’allĂ©gations optimales dans les publicitĂ©s. De surcroĂźt, aucun chercheur ne s’est intĂ©ressĂ© Ă  l’impact du type d’allĂ©gations de la perspective des consommateurs en s’intĂ©ressant Ă  la thĂ©orie de la charge cognitive

    Exposition hydrique au bisphénol A et à ses dérivés chlorés et liens avec le cancer du sein : étude de faisabilité BREDI I (Breast and Endocrine Disrupter Investigation Part 1)

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    Il existe une relation entre exposition aux perturbateurs endocriniens (PE) et carcinogenĂšse animale. Cependant, les donnĂ©es Ă©pidĂ©miologiques sont insuffisantes. Le bisphĂ©nol A (BPA) est un PE ubiquitaire prĂ©sent dans l’eau potable. Ses dĂ©rivĂ©s chlorĂ©s (Clx-BPA) sont suspectĂ©s d’avoir une action PE 100 fois supĂ©rieure. L’objectif de ce travail Ă©tait d’évaluer la faisabilitĂ© d’une Ă©tude d’exposition hydrique au BPA et aux Clx-BPA dans une population de patientes opĂ©rĂ©es du sein. L’étude a Ă©tĂ© menĂ©e au CHU de Poitiers auprĂšs de trois populations de femmes opĂ©rĂ©es du sein classĂ©es selon la gravitĂ© de leur lĂ©sion. Trois façons d’évaluer l’exposition hydrique ont Ă©tĂ© explorĂ©es : dosage dans des matrices biologiques, dans l’eau du robinet et administration d’un questionnaire sociodĂ©mographique validĂ©. Le critĂšre de jugement principal Ă©tait la concentration en composĂ©s dans l’eau ou les matrices biologiques et les quantitĂ©s d’eau apportĂ©es par voie orale et cutanĂ©e selon le questionnaire. Dans l’eau de boisson analysĂ©e, le BPA a Ă©tĂ© quantifiĂ© chez la totalitĂ© des patientes (116 ± 162 ng∙L‑1). Les concentrations en Clx-BPA Ă©taient de 1,85 ± 0,70 ng∙L‑1. Les concentrations urinaires en BPA Ă©taient de 2,6 ng∙mL‑1 en prĂ©opĂ©ratoire et 3,8 ± 5,5 ng∙mL‑1 en postopĂ©ratoire, les Clx-BPA n’ayant pas Ă©tĂ© quantifiĂ©s. Dans le tissu adipeux mammaire, le BPA a Ă©tĂ© retrouvĂ© Ă  1,265 ± 0,058 ng∙g‑1, le BPA et le Clx-BPA n’ayant Ă©tĂ© dĂ©tectĂ©s qu’à deux reprises. Cette Ă©tude a montrĂ© la faisabilitĂ© des dosages du BPA et des Clx-BPA dans les matrices biologiques et l’eau du robinet. La mise en place d’une cohorte multicentrique permettra d’étudier la relation entre exposition Ă  ces PE et cancer du sein.There is a relationship between exposure to endocrine disrupting chemicals (EDCs) and animal carcinogenesis. However, epidemiological data are insufficient. Bisphenol A (BPA) is a ubiquitous EDC present in drinking water. Its chlorinated derivatives (Clx-BPA) are suspected to have an ED action 100 times stronger than BPA itself. The aim of this study was to assess the feasibility of a trial about water exposure to BPA and Clx-BPA in a population of patients having breast surgery. The study was conducted at the University Hospital of Poitiers in three populations of women having breast surgery and classified according to the severity of their injury. Three methods to assess water exposure were explored: determination in biological matrices, in tap water and administration of a validated socio-demographic questionnaire for water exposure. The primary endpoint was the concentration of compounds in water or biological matrices and the amount of water provided by oral and dermal routes according to the questionnaire. In drinking water samples, BPA was quantified for every patient (116 ± 162 ng∙L‑1). Clx-BPA concentrations were 1.85 ±  0.70 g∙L‑1. Urinary BPA concentrations were 2.6 ng∙mL‑1 preoperatively and 3.8 ± 5.5 ng∙mL‑1 postoperatively; CLx-BPA have not been quantified. In breast adipose tissue, BPA was found at 1.265 ± 0.058 ng∙g‑1, whereas BPA and BPA-Clx were only found two times. This study demonstrated the feasibility of BPA and Clx-BPA determinations in biological matrices and tap water. Performing a multicenter cohort study would allow an investigation of the relationship between exposure to EDCs and breast cancer

    Chlorinated and brominated bisphenol A derivatives: Synthesis, characterization and determination in water samples

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    International audienceBisphenol A (BPA) has been used in the plastics industry for several decades. During the treatment of drinking water with chlorine reagent, the formation of chlorinated derivatives of BPA (ClxBPA) but also bromoBPA and bromochloroBPA is to be expected. Some of these compounds are considered to have an estrogenic effect and could induce major risks for human health by targeting different organs and systems in the body. In this paper, we describe the synthesis of chloro- and bromobisphenol A (ClxBPA, BrxBPA, BrxClxBPA)and their analytical characterization. These derivatives could be used as analytical standards in LC-MS/MS or evaluated in in vitro biological tests for their potential as endocrine disruptors. In this study, we evaluated the presence of BPA, ClxBPA in a pilot study from water samples. Range values found for BPA, ClxBPA were respectively 2.8-4169.3 ng/L and 0.8-11.3 ng/L

    Direct Thrombin Inhibitor Prevents Delayed Graft Function in a Porcine Model of Renal Transplantation

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    Chantier qualité GABackground. Kidney transplantations from donors after cardiac arrest (DCA) are characterized by an increase in the occurrence of delayed graft function and primary nonfunction. In this study, Melagatran, a selective reversible direct thrombin inhibitor was used to limit renal injury in a DCA pig kidney transplantation model. Methods. We used a porcine model of DCA to study the effects of treatment with Melagatran in the peri-conservation period. Thromboelastography was used to check Melagatran antithrombin effect on in vitro clot formation. Reverse-transcriptase polymerase chain reaction was used to analyze the peripheral immune cells activation status. Renal function and morphologic study were performed at days 1 and 7. Finally, we analyzed the mechanisms of Melagatran protection on kidney microvasculature primary endothelial cells. Results. Prolongation of coagulation time (Ex-Tem) was observed 10 min after injection; however, Melagatran did not modulate increases of thrombin-antithrombin complexes following reperfusion. Melagatran significant treatment lowered the proinflammatory status of circulating immune cells. Animal's survival was increased in Melagatran-treated groups (9 of 10 in Melagatran groups vs. 4 of 10 in controls at day 7). Renal injury and inflammation were also significantly reduced in treated groups. We also demonstrated a direct protective effect of Melagatran against endothelial cell activation and inflammation in vitro. Conclusion. Direct thrombin inhibitor administration in the periconservation period improved graft outcome and reduced renal injury in a model of DCA

    Structural Basis of Pullulanase Membrane Binding and Secretion Revealed by X-Ray Crystallography, Molecular Dynamics and Biochemical Analysis.

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    International audienceThe Klebsiella lipoprotein pullulanase (PulA) is exported to the periplasm, triacylated, and anchored via lipids in the inner membrane (IM) prior to its transport to the bacterial surface through a type II secretion system (T2SS). X-Ray crystallography and atomistic molecular dynamics (MD) simulations of PulA in a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) model membrane provided an unprecedented molecular view of an N-terminal unstructured tether and the IM lipoprotein retention signal, and revealed novel interactions with the IM via N-terminal immunoglobulin-like domains in PulA. An efficiently secreted nonacylated variant (PulANA) showed similar peripheral membrane association during MD simulations, consistent with the binding of purified PulANA to liposomes. Remarkably, combined X-ray, MD, and functional studies identified a novel subdomain, Ins, inserted in the α-amylase domain, which is required for PulA secretion. Available data support a model in which PulA binding to the IM promotes interactions with the T2SS, possibly via the Ins subdomain

    New method for determining total calcium content in tissue applied to skeletal muscle with and without calsequestrin

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    We describe a new method for determining the concentration of total Ca in whole skeletal muscle samples ([Ca] in units of mmoles/kg wet weight) using the Ca-dependent UV absorbance spectra of the Ca chelator BAPTA (1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid). Muscle tissue was homogenized in a solution containing 0.15 mM BAPTA and 0.5% sodium dodecyl sulfate (to permeabilize membranes and denature proteins) and then centrifuged. The solution volume was adjusted so that BAPTA captured essentially all of the Ca. [Ca] was obtained with Beer's law from the absorbance change produced by adding 1 mM EGTA to capture Ca from BAPTA. Results from mouse, rat, and frog muscles were reasonably consistent with results obtained using other methods for estimating total [Ca] in whole muscles and in single muscle fibers. Results with external Ca removed before determining [Ca] indicate that most of the Ca was intracellular, indicative of a lack of bound Ca in the extracellular space. In both fast-twitch (extensor digitorum longus, EDL) and slow-twitch (soleus) muscles from mice, [Ca] increased approximately linearly with decreasing muscle weight, increasing approximately twofold with a twofold decrease in muscle weight. This suggests that the Ca concentration of smaller muscles might be increased relative to that in larger muscles, thereby increasing the specific force to compensate for the smaller mass. Knocking out the high capacity Ca-binding protein calsequestrin (CSQ) did not significantly reduce [Ca] in mouse EDL or soleus muscle. However, in EDL muscles lacking CSQ, muscle weights were significantly lower than in wild-type (WT) muscles and the values of [CaT]WM were, on average, about half the expected WT values, taking into account the above [Ca] versus muscle weight relationship. Because greater reductions in [Ca] would be predicted in both muscle types, we hypothesize that there is a substantial increase in Ca bound to other sites in the CSQ knockout muscles
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