Quelles questions éthiques posent la production de palmier à huile et la recherche sur les biocarburants ?

At present, palm oil and biofuels arouse both hopes and fears. Palm oil, which is very important for the economy of several Asian and African countries and is used mostly by the food industry and oleochemisty, and very little as for biofuels, has positive and negative impacts on the use of land and the climate. Its production is often criticized from a social point of view and the quality of its oil is discussed from a nutritional point of view. A number of devices are set to encourage firms growing palm trees to have an ethical and deontological approach. Agricultural research institutions (and researchers individually) are increasingly constrained by ethical issues related to biofuels. In France, the Joint Ethics Committee of Inra (Institut national de la recherche agronomique) and Cirad (Centre de coopération internationale en recherche agronomique pour le développement) has recently worked on this question. Biofuels appear as a revealing (in the chemical sense) of a crack in the ethos of those institutions. Cirad and Inra both carry out mission-oriented research. For years, researchers have worked to increase productivity and agricultural revenues, improve food security and market stabilization, reduce inequalities, etc. This mission-oriented research was a moral bail to agricultural productivity. Environmental damages provoked by agriculture and development policies leading to a wide range of problems are undermining the ethos of the two research institutions. Biofuels research, in large terms, is revealing difficulties as different research issues are competing among themselves. The Committee recommended revising the meaning of “mission-oriented research” and made specific recommendations on how to deal with some ethical questions related to biofuels research

Métabolisme de l'arginine dans les entérocytes de rat

info:eu-repo/semantics/publishedComm. Club d'études des cellules épithéliales digestives - Montpellier, 13.12.199

Bioenergies: unveiling the ethos of the agrarian research

Bioenergies: unveiling the ethos of the agrarian research. EurSafe Conference: Global food security: ethical and legal challenge

Arginine metabolism in rat enterocytes

Rat enterocytes exposed to L-arginine in the absence of any other exogenous substrate were found to actively metabolize this cationic amino acid. L-Arginine was converted to L-citrulline either directly in a NADPH-sensitive manner thought to be coupled with the generation of NO, or indirectly through the sequence of reactions catalyzed by arginase and ornithine transcarbamylase. A large fraction of L-citrulline and L-ornithine generated from exogenous L-arginine was released in the incubation medium. The production of CO2 and (poly)amines from L-arginine occurred at rates 2 and 3 orders of magnitude lower than that characterizing the net uptake of the cationic amino acid, and this despite the fact that enterocytes were equipped to allow the interconversion of L-ornithine and L-glutamate. It is concluded that the oxidative catabolism of L-arginine in eneterocytes is quantitatively negligible relative to its conversion to L-citrulline and L-ornithine.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Calbindin D28k in mammalian intestinal absorptive cells: immunohistochemical evidence

Calbindin D28k and D9k are two cytosolic calcium-binding proteins abundant in intestinal absorptive cells which appear to play a role in calcium translocation. Until today, calbindin D28k was found in avian and reptilian absorptive cells but not in mammalian ones. We have described the presence of calbindin D28k-immunoreactivity in intestinal absorptive cells of pig and jerboa (Jaculus jaculus). Pig calbindin D28k-immunoreactive absorptive cells were prominent in duodenum, they were scattered along the villi and nearly absent in the crypts. Jerboa labelled absorptive cells were located along the colonic mucosal surface. No calbindin D28k could be detected in mouse, rat and goat absorptive cells. Topography of calbindin D28k absorptive cells was compared with calbindin D9k distribution. Our results confirmed the data of the literature showing a gradient of labelling increasing from the crypt to the top of the villus and no positive endocrine cell. Young (48 h old) pigs did not expressed calbindin D28k in absorptive cells although calbindin D9k was detected. Calbindin D28K was also observed in endocrine cells which were numerous in pig and goat duodenum and very rare in mouse and jerboa. Western blot experiments confirmed the presence of calbindin D28k in the adult pig intestine, in the jerboa colon and the absence of cross-reactivity between calbindin D28k antibody and calbindin D9k.Comparative StudyJournal ArticleResearch Support, Non-U.S. Gov'tFLWNAinfo:eu-repo/semantics/publishe

The contribution of intestinal gluconeogenesis to glucose homeostasis Is low in 2-day-old pigs1–3

Background: Active gluconeogenesis is essential to maintain blood glucose concentrations in neonatal piglets because of the high glucose requirements after birth. In several adult mammals, the liver, kidney, and possibly the gut may exhibit gluconeogenesis during fasting and insulinopenic conditions. During the postnatal period, the intestine expresses all of the gluconeogenic enzymes, suggesting the potential for gluconeogenesis. Galactose in milk is a potential gluconeogenic precursor for newborns.Objective: Our aim was to quantify the rate of intestinal glucose production from galactose in piglets compared with the overall rate of glucose production.Methods: A single bolus of [U-14C]-galactose was injected into 2-d-old piglets (females and males; mean ± SEM weight: 1.64 ± 0.07 kg) through a gastric catheter. Galactosemia, glycemia, and glucose turnover rate (assessed by monitoring d-[6-3H]-glucose) were monitored. Intestinal glucose production from [U-14C]-galactose was calculated from [U-14C]-glucose appearance in the blood and isotopic dilution. Galactose metabolism was also investigated in vitro in enterocytes isolated from 2-d-old piglets that were incubated with increasing concentrations of galactose.Results: In piglet enterocytes, galactose metabolism was active (mean ± SEM maximum rate of reaction: 2.26 ± 0.45 nmol · min-1 · 106 cells-1) and predominantly oriented toward lactate and pyruvate production (74.0% ± 14.5%) rather than glucose production (26.0% ± 14.5%). In conscious piglets, gastric galactose administration led to an increase in arterial galactosemia (from 0 to 1.0 ± 0.8 mmol/L) and glycemia (35% ± 12%). The initial increase in arterial glycemia after galactose administration was linked to an increase in glucose production rate (33% ± 15%) rather than to a decrease in glucose utilization rate (3% ± 6%). The contribution of intestinal glucose production from galactose was <10% of total glucose production in 2-d-old piglets.br/]Conclusion: Our results indicate that there is a low contribution to glucose homeostasis from intestinal gluconeogenesis in 2-d-old piglets

Different activation patterns of rat xenobiotic metabolism genes by two constituents of garlic

International audienceDiallyl sulfide (DAS) and diallyl disulfide (DADS) are natural components that could account for the anticarcinogenic properties of garlic, at least in part, through the activation of xenobiotic detoxifying metabolism. The aim of this work was to describe the effect of DAS and DADS on xenobiotic-related gene expressions and to study molecular mechanisms relaying DAS effect. We describe the different effects of DAS and DADS on hepatic CYP2B1/2, CYP3A and epoxide hydrolase (EpH) mRNAs in rats, in terms of activation profile, doses and kinetics. The activation profile varied with the mode of chemical administration, i.e. gastric infusion or intraperitoneal (i.p.) injection. Using gastric infusion, DAS and DADS proved different efficiencies at enhancing the mRNA level of the three drug-metabolizing enzymes. After an i.p. administration, we observed a specific activation of CYP2B1/2 gene by DAS. The DAS-mediated CYP2B1/2 activation occurred at transcriptional level and through an okadaic acid-sensitive pathway. In rat livers, a short sequence (NR1) derived from the CYP2B1/2 promoter was stimulated by DAS and we observed a nuclear accumulation of a DNA-protein complex binding NR1. Because constitutively activated receptor (CAR) is a major transcription factor driving the xenobiotic-induced stimulation of CYP2B1/2 through NR1, the role of CAR as a preferential mediator of DAS effect is discussed

Acides gras alimentaires et cancers: mécanismes d'action cellulaire et moléculaire

National audienc

Enjeux éthiques de la prise en charge et de l’accès aux soins pour tous en situation de forte tension liée à l’épidémie de Covid-19: Réponse à la saisine du ministre des solidarités et de la santé (novembre 2020)

La tension qui s’exerce sur le système sanitaire, révélée à l’occasion de l’épidémie de Covid-19, traduit l’insuffisance des moyens au regard des besoins de santé. Elle est liée, d’une part, à l’accélération de la propagation du virus qui affecte, de façon particulièrement inégalitaire, un nombre très élevé de personnes et, d’autre part, aux limites du système de santé lui-même en termes de capacités et de ressources humaines. Si l’adaptation des capacités (par exemple, augmentation du nombre de lits de réanimation ou de lits de médecine) est théoriquement toujours possible, l’augmentation des ressources humaines, qu’il s’agisse des personnels médicaux ou paramédicaux, n’est pas réalisable dans un délai court, puisqu’elle est tributaire du recrutement et de la formation de ces professionnels. (Premier paragraphe