PPH dendrimers grafted on silica nanoparticles: surface chemistry, characterization, silver colloids hosting and antibacterial activity

Polyphosphorhydrazone (PPH) dendrimers have been grafted on silica nanoparticles, and the surface functions of the dendrimers have been derivatized to phosphonates with lateral poly(ethyleneglycol) (PEG) chains. All materials have been thoroughly characterized by MAS NMR, FT-IR, electron microscopy, TGA and elemental analysis. These materials successfully hosted silver and silver oxide nanoparticles. The resulting composites exhibit antibacterial activity

Urgences aortiques en pré hospitalier (étude rétrospective sur 40 mois d'activité au SMUR de Montfermeil)

ST QUENTIN EN YVELINES-BU (782972101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Velamo do Campo : Its Volatile Constituents, Secretory Elements, and Biological Activity

International audienc

Velamo do Campo

International audienc

Role of angiotensin III in hypertension

International audienceThe hyperactivity of the brain renin-angiotensin system (RAS) has been implicated in the development and maintenance of hypertension in several types of experimental and genetic hypertension animal models. Among the main bio-active peptides of the brain RAS, angiotensin (Ang) II and Ang III display the same affinity for type 1 and type 2 Ang II receptors. Both peptides, injected intracerebroventricularly, similarly increase blood pressure (BP); however, because Ang II is converted in vivo to Ang III, the identity of the true effector is unknown. In this article, we review new insights into the predominant role of brain Ang III in the control of BP, underlining the fact that brain aminopeptidase A (APA), the enzyme-forming central Ang III, could constitute a putative central therapeutic target for the treatment of hypertension. This justifies the development of potent systemically active APA inhibitors, such as RB150, as prototypes of a new class of antihypertensive agents for the treatment of certain forms of hypertension

Asp218 participates with Asp213 to bind a Ca2+ atom into the S1 subsite of aminopeptidase A: a key element for substrate specificity.

International audienceAPA (aminopeptidase A; EC 3.4.11.7) is a membrane-bound zinc metallopeptidase, also activated by Ca(2+), involved in the formation of brain angiotensin III, which exerts a tonic stimulatory action on the central control of blood pressure in hypertensive animals. In the present study, in the three-dimensional model of the ectodomain of mouse APA, we docked the specific APA inhibitor glutamate phosphonate, in the presence of Ca(2+). The model showed the presence of one Ca(2+) atom in an hydrophilic pocket corresponding to the S1 subsite in which the lateral chain of the inhibitor is pointing. In this pocket, the Ca(2+) atom was hexaco-ordinated with the acidic side chains of Asp(213) and Asp(218), the carbonyl group of Glu(215) and three water molecules, one of them being engaged in a hydrogen bond with the negatively charged carboxylate side chain of the inhibitor. Mutagenic replacement of Asp(213) and Asp(218) with a conservative residue maintained the ability of mutated APAs to be activated by Ca(2+). However, the replacement by a non-conservative residue abolished this property, demonstrating the crucial role of these residues in Ca(2+) binding. We also showed the involvement of these residues in the strict specificity of APA in the presence of Ca(2+) for N-terminal acidic residues from substrates or inhibitors, since mutagenic replacement of Asp(213) and Asp(218) induced a decrease of the inhibitory potencies of inhibitors homologous with acidic residues. Finally, this led to the rational design of a new potent APA inhibitor, NI926 (K(i)=70 nM), which allowed us to precisely localize Asp(213) at the entrance and Asp(218) at the bottom of the S1 subsite. Taken together, these data provide new insight into the organization and functional role of the APA S1 subsite and will allow the design of pharmacophore of the inhibitor, helpful for the development of a new generation of APA inhibitors as central-acting antihypertensive agents

Sciences pour les Exoplanètes et les Systèmes Planétaires: websites and e-learning

International audienceThe websites « Sciences pour les Exoplanètes et les Systèmes Planétaires » (SESP) and « Exoplanètes » have been created in the context of the LabEx ESEP (Laboratoire d’excellence Exploration Spatiale des Environnements Planétaires) [1]. They present planetary and exoplanetary sciences with courses, interactive tools, and a didactic catalogue connected to the Encyclopedia http://exoplanet.eu [2]. These resources are directed towards undergraduate level. They will be used as support for face-to-face courses and self-training. In the future, we will translate some contents into English and create e-learning degree courses

Genome sequence of the euryhaline Javafish medaka, Oryzias javanicus: a small aquarium fish model for studies on adaptation to salinity

Background: The genus Oryzias is constituted of 35 medaka-fish species each exhibiting various ecological, morphological and physiological peculiarities and adaptations. Beyond of being a comprehensive phylogenetic group for studying intra-genus evolution of several traits like sex determination, behaviour, morphology or adaptation through comparative genomic approaches, all medaka species share many advantages of experimental model organisms including small size and short generation time, transparent embryos and genome editing tools for reverse and forward genetic studies. The Java medaka, Oryzias javanicus, is one of the two species of medaka perfectly adapted for living in brackish/sea-waters. Being an important component of the mangrove ecosystem, O. javanicus is also used as a valuable marine test-fish for ecotoxicology studies. Here, we sequenced and assembled the whole genome of O. javanicus, and anticipate this resource will be catalytic for a wide range of comparative genomic, phylogenetic and functional studies. Findings: Complementary sequencing approaches including long-read technology and data integration with a genetic map allowed the final assembly of 908 Mbp of the O. javanicus genome. Further analyses estimate that the O. javanicus genome contains 33% of repeat sequences and has a heterozygosity of 0.96%. The achieved draft assembly contains 525 scaffolds with a total length of 809.7 Mbp, a N50 of 6.3 Mbp and a L50 of 37 scaffolds. We identified 21454 expressed transcripts for a total transcriptome size of 57, 146, 583 bps. Conclusions: We provide here a high-quality draft genome assembly of the euryhaline Javafish medaka, and give emphasis on the evolutionary adaptation to salinity