Implication zootechnique du menthol cristallisé comme additif alimentaire chez le poulet de chair

Le menthol est utilisé pour ses vertus aromatiques, culinaires, cosmétiques et médicinales. Chez l’homme, il est employé contre les troubles digestifs et l’hypotension, mais présente, également, des propriétés antiseptiques et bactéricides. En médecine vétérinaire, il entre dans de nombreuses spécialités médicamenteuses à visée respiratoire. Cependant, son usage en tant qu’additif antibactérien n’a pas encore été rapporté. L’objectif est de cette étude tester si ce produit pourrait substituer les principes chimiques incriminés d’être à l’origine d’antibiorésistance, de résidus dans les denrées alimentaires, d’écotoxicité et d’allergies chez le consommateur. Le dispositif expérimental est composé de 4 parquets abritant chacun 100 poulets type chair. Trois lots (MCd1, MCd2, MCd3) ont été supplémentés avec du menthol cristallisé (MC) dans l’eau de boisson aux doses respectives d1=0,10mg/kgPV (Poids Vif), d2=0,20mg/kgPV et d3=0,30mg/kgPV. Le quatrième lot est choisi comme témoin (T). Le traitement a duré 10 jours répartis en trois périodes différents: J6-J9, J21-J23 et J33-J35. Les résultats ont démontré que la posologie d2=0,2mg/kgPV est la plus efficace sur le plan zootechnique : poids vif total (+9,07%), gain moyen quotidien (+1,88%), indice de consommation (-5,44%), taux de mortalité (-50%). Ces résultats, bien que préliminaires, ouvrent une voie de recherche intéressante pour l’usage des produits naturels à des fins zootechniques et thérapeutiques. Cependant, des études complémentaires sont nécessaires pour élucider les effets pharmacologiques, toxicologiques et diététiques du menthol

Implication zootechnique du menthol cristallisé comme additif alimentaire chez le poulet de chair

Le menthol est utilisé pour ses vertus aromatiques, culinaires, cosmétiques et médicinales. Chez l’homme, il est employé contre les troubles digestifs et l’hypotension, mais présente, également, des propriétés antiseptiques et bactéricides. En médecine vétérinaire, il entre dans de nombreuses spécialités médicamenteuses à visée respiratoire. Cependant, son usage en tant qu’additif antibactérien n’a pas encore été rapporté. L’objectif est de cette étude tester si ce produit pourrait substituer les principes chimiques incriminés d’être à l’origine d’antibiorésistance, de résidus dans les denrées alimentaires, d’écotoxicité et d’allergies chez le consommateur. Le dispositif expérimental est composé de 4 parquets abritant chacun 100 poulets type chair. Trois lots (MCd1, MCd2, MCd3) ont été supplémentés avec du menthol cristallisé (MC) dans l’eau de boisson aux doses respectives d1=0,10mg/kgPV (Poids Vif), d2=0,20mg/kgPV et d3=0,30mg/kgPV. Le quatrième lot est choisi comme témoin (T). Le traitement a duré 10 jours répartis en trois périodes différents: J6-J9, J21-J23 et J33-J35. Les résultats ont démontré que la posologie d2=0,2mg/kgPV est la plus efficace sur le plan zootechnique : poids vif total (+9,07%), gain moyen quotidien (+1,88%), indice de consommation (-5,44%), taux de mortalité (-50%). Ces résultats, bien que préliminaires, ouvrent une voie de recherche intéressante pour l’usage des produits naturels à des fins zootechniques et thérapeutiques. Cependant, des études complémentaires sont nécessaires pour élucider les effets pharmacologiques, toxicologiques et diététiques du menthol

Computational fragment-based drug design to explore the hydrophobic subpocket of the mitotic kinesin Eg5 allosteric binding site

International audienceEg5, a mitotic kinesin exclusively involved in the formation and function of the mitotic spindle has attracted interest as an anticancer drug target. Eg5 is co-crystallized with several inhibitors bound to its allosteric binding pocket. Each of these occupies a pocket formed by loop 5/helix alpha2 (L5/alpha2). Recently designed inhibitors additionally occupy a hydrophobic pocket of this site. The goal of the present study was to explore this hydrophobic pocket with our MED-SuMo fragment-based protocol, and thus discover novel chemical structures that might bind as inhibitors. The MED-SuMo software is able to compare and superimpose similar interaction surfaces upon the whole protein data bank (PDB). In a fragment-based protocol, MED-SuMo retrieves MED-Portions that encode protein-fragment binding sites and are derived from cross-mining protein-ligand structures with libraries of small molecules. Furthermore we have excluded intra-family MED-Portions derived from Eg5 ligands that occupy the hydrophobic pocket and predicted new potential ligands by hybridization that would fill simultaneously both pockets. Some of the latter having original scaffolds and substituents in the hydrophobic pocket are identified in libraries of synthetically accessible molecules by the MED-Search software

A supramolecular helix that disregards chirality

The functions of complex crystalline systems derived from supramolecular biological and non-biological assemblies typically emerge from homochiral programmed primary structures via first principles involving secondary, tertiary and quaternary structures. In contrast, heterochiral and racemic compounds yield disordered crystals, amorphous solids or liquids. Here, we report the self-assembly of perylene bisimide derivatives in a supramolecular helix that in turn self-organizes in columnar hexagonal crystalline domains regardless of the enantiomeric purity of the perylene bisimide. We show that both homochiral and racemic perylene bisimide compounds, including a mixture of 21 diastereomers that cannot be deracemized at the molecular level, self-organize to form single-handed helical assemblies with identical single-crystal-like order. We propose that this high crystalline order is generated via a cogwheel mechanism that disregards the chirality of the self-assembling building blocks. We anticipate that this mechanism will facilitate access to previously inaccessible complex crystalline systems from racemic and homochiral building blocks

Tools and data services registry: a community effort to document bioinformatics resources.

Life sciences are yielding huge data sets that underpin scientific discoveries fundamental to improvement in human health, agriculture and the environment. In support of these discoveries, a plethora of databases and tools are deployed, in technically complex and diverse implementations, across a spectrum of scientific disciplines. The corpus of documentation of these resources is fragmented across the Web, with much redundancy, and has lacked a common standard of information. The outcome is that scientists must often struggle to find, understand, compare and use the best resources for the task at hand.Here we present a community-driven curation effort, supported by ELIXIR-the European infrastructure for biological information-that aspires to a comprehensive and consistent registry of information about bioinformatics resources. The sustainable upkeep of this Tools and Data Services Registry is assured by a curation effort driven by and tailored to local needs, and shared amongst a network of engaged partners.As of November 2015, the registry includes 1785 resources, with depositions from 126 individual registrations including 52 institutional providers and 74 individuals. With community support, the registry can become a standard for dissemination of information about bioinformatics resources: we welcome everyone to join us in this common endeavour. The registry is freely available at https://bio.tools

A review of the systematic biology of fossil and living bony-tongue fishes, Osteoglossomorpha (Actinopterygii: Teleostei)

The bony-tongue fishes, Osteoglossomorpha, have been the focus of a great deal of morphological, systematic, and evolutionary study, due in part to their basal position among extant teleostean fishes. This group includes the mooneyes (Hiodontidae), knifefishes (Notopteridae), the abu (Gymnarchidae), elephantfishes (Mormyridae), arawanas and pirarucu (Osteoglossidae), and the African butterfly fish (Pantodontidae). This morphologically heterogeneous group also has a long and diverse fossil record, including taxa from all continents and both freshwater and marine deposits. The phylogenetic relationships among most extant osteoglossomorph families are widely agreed upon. However, there is still much to discover about the systematic biology of these fishes, particularly with regard to the phylogenetic affinities of several fossil taxa, within Mormyridae, and the position of Pantodon. In this paper we review the state of knowledge for osteoglossomorph fishes. We first provide an overview of the diversity of Osteoglossomorpha, and then discuss studies of the phylogeny of Osteoglossomorpha from both morphological and molecular perspectives, as well as biogeographic analyses of the group. Finally, we offer our perspectives on future needs for research on the systematic biology of Osteoglossomorpha

Community-Driven Data Analysis Training for Biology

The primary problem with the explosion of biomedical datasets is not the data, not computational resources, and not the required storage space, but the general lack of trained and skilled researchers to manipulate and analyze these data. Eliminating this problem requires development of comprehensive educational resources. Here we present a community-driven framework that enables modern, interactive teaching of data analytics in life sciences and facilitates the development of training materials. The key feature of our system is that it is not a static but a continuously improved collection of tutorials. By coupling tutorials with a web-based analysis framework, biomedical researchers can learn by performing computation themselves through a web browser without the need to install software or search for example datasets. Our ultimate goal is to expand the breadth of training materials to include fundamental statistical and data science topics and to precipitate a complete re-engineering of undergraduate and graduate curricula in life sciences. This project is accessible at https://training.galaxyproject.org. We developed an infrastructure that facilitates data analysis training in life sciences. It is an interactive learning platform tuned for current types of data and research problems. Importantly, it provides a means for community-wide content creation and maintenance and, finally, enables trainers and trainees to use the tutorials in a variety of situations, such as those where reliable Internet access is unavailable

Enantioselective component selection in multicomponent supramolecular gels

We investigate a two-component acid-amine gelation system in which chirality plays a vital role. A carboxylic acid based on a second generation l-lysine dendron interacts with chiral amines and subsequently assembles into supramolecular gel fibers. The chirality of the amine controls the assembly of the resulting diastereomeric complexes, even if this chirality is relatively "poor quality". Importantly, the selective incorporation of one enantiomer of an amine over the other into the gel network has been demonstrated, with the R amine that forms complexes which assemble into the most stable gel being primarily selected for incorporation. Thermodynamic control has been proven by forming a gel exclusively with an S amine, allowing the R enantiomer to diffuse through the gel network, and displacing it from the "solidlike" fibers, demonstrating that these gels adapt and evolve in response to chemical stimuli to which they are exposed. Excess amine, which remains unincorporated within the solidlike gel fiber network, can diffuse out and be reacted with an isocyanate, allowing us to quantify the enantioselectivity of component selection but also demonstrating how gels can act as selective reservoirs of potential reagents, releasing them on demand to undergo further reactions; hence, component-selective gel assembly can be coupled with controlled reactivity