54 research outputs found
Génétique de la couleur de la toison des races ovines françaises solognote, bizet et berrichonne
International audienc
GĂNĂTIQUE DE LA COULEUR DE LA TOISON DES RACES OVINES FRANĂAISES SOLOGNOTE, BIZET ET BERRICHONNE
FERTILITĂ COMPARĂE DES BREBIS DE FORMULE E+E+ ET EdE+ AU LOCUS D'EXTENSION POUR LA COLORATION DE LA TOISON
Social Software for Supporting Interaction in a Community of Practice Dedicated to e-Learning
Regioselective Wacker Oxidation of Internal Alkenes: Rapid Access to Functionalized Ketones Facilitated by Cross-Metathesis
Functional impairment of systemic scleroderma patients with digital ulcerations: Results from the DUO registry
Demographic, clinical and antibody characteristics of patients with digital ulcers in systemic sclerosis: data from the DUO Registry
OBJECTIVES: The Digital Ulcers Outcome (DUO) Registry was designed to describe the clinical and antibody characteristics, disease course and outcomes of patients with digital ulcers associated with systemic sclerosis (SSc).
METHODS: The DUO Registry is a European, prospective, multicentre, observational, registry of SSc patients with ongoing digital ulcer disease, irrespective of treatment regimen. Data collected included demographics, SSc duration, SSc subset, internal organ manifestations, autoantibodies, previous and ongoing interventions and complications related to digital ulcers.
RESULTS: Up to 19 November 2010 a total of 2439 patients had enrolled into the registry. Most were classified as either limited cutaneous SSc (lcSSc; 52.2%) or diffuse cutaneous SSc (dcSSc; 36.9%). Digital ulcers developed earlier in patients with dcSSc compared with lcSSc. Almost all patients (95.7%) tested positive for antinuclear antibodies, 45.2% for anti-scleroderma-70 and 43.6% for anticentromere antibodies (ACA). The first digital ulcer in the anti-scleroderma-70-positive patient cohort occurred approximately 5 years earlier than the ACA-positive patient group.
CONCLUSIONS: This study provides data from a large cohort of SSc patients with a history of digital ulcers. The early occurrence and high frequency of digital ulcer complications are especially seen in patients with dcSSc and/or anti-scleroderma-70 antibodies
ChemInform Abstract: Chelation-Controlled Additions to α-Silyloxy Aldehydes: An Autocatalytic Approach.
Application de la rĂ©action de mĂ©tathĂšse d'olĂ©fines Ă l'obtention de molĂ©cules d'intĂ©rĂȘt biologique
C-C bond formation constitutes a key research field of organic chemistry. Among all existing techniques, olefinmetathesis turned out to be a revolution, especially since efficient and functional groups tolerant catalysts havebeen developed. Herein, the application of this reaction has been considered to three targets of biological interest:diospongin A, nhatrangin A and berkeleyamide A.Numerous bioactive natural products belong to 1,7-diarylheptanoĂŻd or 1,9-diarylnonanoĂŻd families.Springing from the first one, diospongin A revealed promising anti-osteoporotic properties. Conversely, no naturalproduct from 1,8-diaryloctanoĂŻds has been reported to date. Willing to study the potential activity of suchcompounds, several diospongin A homologues series have been synthesized, involving especially a Prinscyclisation for the formation of a common tetrahydropyran scaffold, followed by a cross metathesis / Wackeroxidation sequence, for the introduction of the chemical diversity.Nhatrangin A, recently isolated from the cyanobacteria Lyngbya majuscula, has showed a potentialactivity against the CoL-2 human cancer cell line. As no total synthesis of this molecule has been reported todate, four disconnections have been considered herein, respectively involving a ring closing metathesis, a crossmetathesis, an enantioselective organocatalysed Michael addition or a Myers diastereoselective alkylation as keystep. All these approaches have in common the use of a trans aldol reaction. An advanced intermediate has thusbeen obtained.Berkeleyamide A, isolated from the fungus Penicillium rubrum, possess a micromolar inhibitive activitytoward MMP-3 and caspases-1 enzymes, taking part in particular in cancer cells growth. Three total synthesis ofthis molecule have already been reported, all sharing to start from the chiral pool. Two âretronâ approaches havebeen considered herein, involving especially an imine diastereoselective allylation, a cross metathesis and a Hecktype cyclisation. This led to the obtaining of the carbon backbone of the molecule.La formation de liaisons C-C constitue un sujet de recherche primordial en chimie organique. Parmitoutes les techniques existantes, la mĂ©tathĂšse dâolĂ©fines a constituĂ© une vĂ©ritable rĂ©volution, notamment grĂąceau dĂ©veloppement de catalyseurs efficaces et tolĂ©rants vis-Ă -vis de bon nombre de groupements fonctionnels.Cette rĂ©action a Ă©tĂ© envisagĂ©e ici sur trois cibles dâintĂ©rĂȘt biologique : la diospongine A, la nhatrangine A et leberkeleyamide A.De nombreuses molĂ©cules naturelles bioactives appartiennent aux familles des 1,7-diarylheptanoĂŻdes et1,9-diarylnonanoĂŻdes. Issue de la premiĂšre, la diospongine A a dĂ©voilĂ© des propriĂ©tĂ©s anti-ostĂ©oporotiquesprometteuses. A lâinverse, aucun produit naturel 1,8-diaryloctanoĂŻde nâa encore Ă©tĂ© rapportĂ©. DĂ©sireux dâĂ©tudier lapotentielle activitĂ© de tels composĂ©s, plusieurs sĂ©ries dâhomologues de la diospongine A ont Ă©tĂ© synthĂ©tisĂ©es,impliquant la formation dâintermĂ©diaires tĂ©trahydropyraniques communs par cyclisation de Prins, suivi dâunesĂ©quence mĂ©tathĂšse croisĂ©e / oxydation de Wacker, permettant ainsi lâintroduction de la diversitĂ© chimique.La nhatrangine A, rĂ©cemment isolĂ©e de la cyanobactĂ©rie Lyngbya majuscula, a montrĂ© une potentielleactivitĂ© contre la lignĂ©e cancĂ©reuse CoL-2. Aucune synthĂšse nâayant encore Ă©tĂ© rapportĂ©e, quatre dĂ©connectionsont ici Ă©tĂ© envisagĂ©es, impliquant respectivement une mĂ©tathĂšse cyclisante, une mĂ©tathĂšse croisĂ©e, une additionde Michael Ă©nantiosĂ©lective organocatalysĂ©e ou encore une alkylation diastĂ©rĂ©osĂ©lective selon Myers commeĂ©tape clĂ©. Toutes ces approches ont en commun lâutilisation dâune rĂ©action de trans aldolisation. Un intermĂ©diaireavancĂ© a ainsi pu ĂȘtre synthĂ©tisĂ©.Le berkeleyamide A, isolĂ© du champignon Penicillium rubrum, est une molĂ©cule possĂ©dant une activitĂ©inhibitrice micromolaire des enzymes MMP-3 et caspases-1, impliquĂ©es notamment dans la croissance descellules cancĂ©reuses. Trois synthĂšses de ce composĂ© sont dĂ©jĂ dĂ©crites dans la littĂ©rature, toutes dĂ©marrant dupool chiral. Deux approches « rĂ©tron » sont ici proposĂ©es, impliquant notamment une allylation diastĂ©rĂ©osĂ©lectivedâimine, une mĂ©tathĂšse croisĂ©e et une cyclisation de type Heck. Le squelette carbonĂ© de la molĂ©cule a ainsi Ă©tĂ©obtenu
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