Palladium-Catalyzed Allylation/Benzylation of H-Phosphinate Esters with Alcohols

The Pd-catalyzed direct alkylation of H-phosphinic acids and hypophosphorous acid with allylic/benzylic alcohols has been described previously. Here, the extension of this methodology to H-phosphinate esters is presented. The new reaction appears general, although its scope is narrower than with the acids, and its mechanism is likely different. Various alcohols are examined in their reaction with phosphinylidene compounds R1R 2P(O)H

Parasitoses digestives chez le jeune enfant en milieu extra-hospitalier tropical

Une étude copro-parasitologique est effectuée, dans un village du Sud-Togo, chez des enfants de 6 mois à 3 ans faisant l'objet d'un suivi nutritionnel. Ce travail montre que 42,5 % des enfants sont porteurs de parasites et 12,1 % polyparasités. Les parasites les plus fréquents sont : Giardia (21 %), Ankylostome (13 %) et Ascaris (12,5 %). Le parasitisme et le polyparasitisme s'observent respectivement à partir de 9 mois et 18 mois et leurs fréquences augmentent avec l'âge. En revanche, la fréquence des selles diarrhéiques décroît avec l'âge et aucun parasite ne semble directement et exclusivement à l'origine de ces diarrhées. La répartition des parasites et des selles diarrhéiques est indépendante du sexe. Aucune relation n'a été mise en évidence entre l'état nutritionnel et la fréquence des parasites et des selles diarrhéiques. Après traitement, les taux de réinfestation sont élevés pour Ankylostome (65 %), Tricocéphale (50 %) et Giardia (34,2 %). (Résumé d'auteur

Iron deficiency, cell-mediated immunity and infection among 6-36 month old children living in rural Togo

Relationships between iron deficiency, cell-mediated immunity (CMI) and morbidity were studied in 220 children in rural south Togo. Iron deficiency was defined by abnormal values of at least two biochemical indicators of iron status viz. (i) plasmat ferritin, (ii) transferrin saturation, (iii) erythrocyte protophorphyrin. In children without any sign of inflammation, the percentage of B lymphocytes was higher in iron-deficient than in iron-sufficient children (26.7 +/- 2.9 vs 18 +/- 1.5). Mature T lymphocyte and helper-inducer T lymphocyte percentages were lower (51.6 +/- 3.7 vs 62.2 +/- 1.6 and 32.5 +/- 2.4 vs 38.7 +/- 1.4, p <0.05 respectively). The number of mature T and helper-inducer T lympphocytes was inversely related to iron status. No alteration of the CMI function assessed by delayed skin hypersensitivity was observed. Prevalence of diarrhea, upper respiratory tract infections and febrile episodes was increased in iron-deficient children. (Résumé d'auteur

Blunting the response to endotoxin in healthy subjects: effects of various doses of intravenous fish oil

Objective: To test the dose response effect of infused fish oil (FO) rich in n-3 PUFAs on the inflammatory response to endotoxin (LPS) and on membrane incorporation of fatty acids in healthy subjects. Design: Prospective, sequential investigation comparing three different FO doses. Subjects: Three groups of male subjects aged 26.8±3.2years (BMI 22.5±2.1). Intervention: One of three FO doses (Omegaven®10%) as a slow infusion before LPS: 0.5g/kg 1day before LPS, 0.2g/kg 1day before, or 0.2g/kg 2h before. Measurements and results: Temperature, hemodynamic variables, indirect calorimetry and blood samples (TNF-α, stress hormones) were collected. After LPS temperature, ACTH and TNF-α concentrations increased in the three groups: the responses were significantly blunted (p<0.0001) compared with the control group of the Pluess et al. trial. Cortisol was unchanged. Lowest plasma ACTH, TNF-α and temperature AUC values were observed after a single 0.2g/kg dose of FO. EPA incorporation into platelet membranes was dose-dependent. Conclusions: Having previously shown that the response to LPS was reproducible, this study shows that three FO doses blunted it to various degrees. The 0.2g/kg perfusion immediately before LPS was the most efficient in blunting the responses, suggesting LPS capture in addition to the systemic and membrane effect

Undetectable levels of N6-methyl adenine in mouse DNA: Cloning and analysis of PRED28, a gene coding for a putative mammalian DNA adenine methyltransferase.

International audienceThree methylated bases, 5-methylcytosine, N4-methylcytosine and N6-methyladenine (m6A), can be found in DNA. However, to date, only 5-methylcytosine has been detected in mammalian genomes. To reinvestigate the presence of m6A in mammalian DNA, we used a highly sensitive method capable of detecting one N6-methyldeoxyadenosine per million nucleosides. Our results suggest that the total mouse genome contains, if any, less than 10(3) m6A. Experiments were next performed on PRED28, a putative mammalian N6-DNA methyltransferase. The murine PRED28 encodes two alternatively spliced RNA. However, although recombinant PRED28 proteins are found in the nucleus, no evidence for an adenine-methyltransferase activity was detected

Effects of endotoxin on lactate metabolism in humans.

ABSTRACT: INTRODUCTION: Hyperlactatemia represents one prominent component of the metabolic response to sepsis. In critically ill patients, hyperlactatemia is related to the severity of the underlying condition. Both an increased production and a decreased utilization and clearance might be involved in this process, but their relative contribution remains unknown. The present study aimed at assessing systemic and muscle lactate production and systemic lactate clearance in healthy human volunteers, using intravenous endotoxin (LPS) challenge. METHODS: Fourteen healthy male volunteers were enrolled in 2 consecutive studies (n = 6 in trial 1 and n = 8 in trial 2). Each subject took part in one of two investigation days (LPS-day with endotoxin injection and placebo-day with saline injection) separated by one week at least and in a random order. In trial 1, their muscle lactate metabolism was monitored using microdialysis. In trial 2, their systemic lactate metabolism was monitored by means of a constant infusion of exogenous lactate. Energy metabolism was monitored by indirect calorimetry and glucose kinetics was measured with 6,6-H2 glucose. RESULTS: In both trials, LPS increased energy expenditure (p = 0.011), lipid oxidation (p&lt;0.0001), and plasma lactate concentration (p = 0.016). In trial 1, lactate concentration in the muscle microdialysate was higher than in blood, indicating lactate production by muscles. This was, however, similar with and without LPS. In trial 2, calculated systemic lactate production increased after LPS (p = 0.031), while lactate clearance remained unchanged. CONCLUSIONS: LPS administration increases lactatemia by increasing lactate production rather than by decreasing lactate clearance. Muscle is, however, unlikely to be a major contributor to this increase in lactate production. TRIAL REGISTRATION: ClinicalTrials.gov NCT01647997

X-ray computed tomography for characterization of expanded polystyrene (EPS) foam

Expanded polystyrene (EPS) foam is widely used in building and construction applications for thermal and acoustic insulation. This material is nearly transparent for X-rays, making it difficult to characterize its pore structure in 3D with X-ray tomography. Because of this difficulty, the pore network is often not investigated and is, thus, poorly known. Since this network controls different physical properties, such as the sound absorption, it is crucial to understand its overall structure. In this manuscript, we show how to reveal the pore network of EPS foams through the combination of high resolution X-ray tomography (micro-CT) and saturation techniques. The foams were saturated with CsCl-brine, which acts as a contrasting agent in X-ray micro-CT imaging. This allowed us to separate the beads, making up the foam, from the pore network. Based on the 3D micro-CT results, we were able to assess a representative elementary volume for the polystyrene, which allows for calculating the acoustical parameters from the Johnson-Champoux-Allard (JCA) model, the pore and bead size distribution. The 3D data was also used as input to simulate sound absorption curves. The parametric study showed that an increase in the bead size influenced the sound absorption of the material. We showed that, by doubling the diameter of beads, the absorption coefficient was doubled in certain ranges of frequency

First report of Cloeon vanharteni Gattolliat & Sartori, 2008 (Baetidae, Ephemeroptera) in the Maghreb

Cloeon vanharteni Gattolliat & Sartori, 2008 was newly discovered in the framework of our study of Ephemeroptera in the Draa basin, located in the southern region of the High Atlas in Morocco. This discovery is rather unexpected as the species was never reported outside the Arabian Peninsula and Levant; it is thus the first record for the Maghreb. The identification was based on morphological evidence and confirmed by the mitochondrial COI barcode