Paradoxical embolism following thromboaspiration of an arteriovenous fistula thrombosis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Paradoxical embolism is an increasingly reported cause of arterial embolism. Several embolic sources have been described, but thrombosis of an arteriovenous fistula as a paradoxical emboligenic source has not, to the best of our knowledge, been reported.</p> <p>Case presentation</p> <p>A 50-year-old Caucasian woman received a renal graft for primary hyperoxaluria. After transplantation, she was maintained on daily hemodialysis. Thrombosis of her arteriovenous fistula occurred two weeks post-transplantation and was treated by thromboaspiration, which was partially successful. During a hemodialysis session immediately following thromboaspiration, she developed a coma with tetraplegia requiring intensive cardiorespiratory resuscitation. Brain magnetic resonance imaging revealed various hyperdense areas in the vertebrobasilar territory resulting from bilateral occlusion of posterior cerebral arteries. Transesophageal echocardiographic examination showed a patent foramen ovale, while pulse echography of the arteriovenous fistula revealed the persistence of extensive clots that were probably the embolic source. A paradoxical embolus through a patent foramen ovale was suggested because of the proximity of the neurological event to the thrombectomy procedure.</p> <p>Conclusions</p> <p>The risk of paradoxical embolism in a hemodialyzed patient with a patent foramen ovale deserves consideration and requires careful evaluation in situations of arteriovenous fistula thrombosis.</p

NODULES THYRODIENS DE L'ADULTE (TECHNIQUE ET INTERETS DE LA CYTOPONCTION ECHOGUIDEE A L'AIGUILLE FINE ET EVALUATION DES CRITERES ECHOGRAPHIQUES. ETUDE PROSPECTIVE REALISEE AU CHU D'AMIENS)

AMIENS-BU Santé (800212102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Propriétés sélectionnées des dendrimères phosphorés : approches vertes de la catalyse

International audienceThis review describes the synthesis of polyphosphorhydrazone (PPH) dendrimers, which are highly branched macromolecules, having a phosphorus atom at each branching point. The properties of these PPH dendrimers in the field of catalysis are then described. The review is organized to illustrate in the first part how the specificities of dendrimers could contribute to green chemistry. This concerns in particular the dendritic effect that is an increased efficiency (yield, enantioselectivity, etc.) when the size of the dendrimer increases, the recovery and reuse of the dendritic catalyst, the decreased leaching, and the entrapping of nanoparticles. In a second part, some even greener approaches of catalysis with dendrimers will be displayed, such as catalysis in water, switchable catalysis, and organocatalysis (no metal used). Different types of catalytic reactions have been studied, such as Stille, Suzuki and Sonogashira couplings, Knoevenagel condensations, Michael additions, asymmetric allylic alkylations, O- and N-arylation and vinylation reactions, [2+2+2]-cycloaddition reactions, isomerization of 1-octan-3-ol, Friedel–Crafts acylations, Heck reactions, hydrogenations, hydrations, transfer hydrogenations, amination of β-dicarbonyl compounds, etc.Cette revue décrit la synthèse des dendrimères polyphosphorhydrazone (PPH), qui sont des macromolécules hautement ramifiées, possédant un atome de phosphore à chaque point de ramification. Les propriétés de ces dendrimères PPH dans le domaine de la catalyse sont ensuite décrites. Dans une première partie seront illustrées comment les spécificités des dendrimères peuvent contribuer à la chimie verte. Ceci concerne en particulier l’effet dendritique qui est un accroissement de l’efficacité (rendement, énantiosélectivité, etc ...) lorsque la taille du dendrimère augmente, la récupération et la réutilisation du catalyseur dendritique, la diminution de la lixiviation et le piégeage des nanoparticules. Dans une deuxième partie, des approches encore plus vertes de la catalyse avec des dendrimères seront présentées, comme la catalyse dans l’eau, la catalyse commutable et l’organocatalyse (aucun métal utilisé). Différents types de réactions catalytiques sont rapportés, tels que les couplages de Stille, Suzuki et Sonogashira, les condensations de Knoevenagel, les additions de Michael, les alkylations allyliques asymétriques, les réactions de O- et N-arylation et de vinylation, les réactions de cycloaddition [2+2+2], l’isomérisation du 1-octan-3-ol, les acylations de Friedel–Crafts, les réactions de Heck, les hydrogénations, les hydratations, l’hydrogénation par transfert, l’amination de composés β-dicarbonyle, etc

Two-Photon Absorbing Dendrimers and Their Properties—An Overview

International audienceThis review describes the two-photon absorption properties of dendrimers, which are arborescent three-dimensional macromolecules differing from polymers by their perfectly defined structure. The two-photon absorption process is a third order non-linear optical property that is attractive because it can be used in a wide range of applications. In this review, dendrimers that were studied for their two-photon absorption properties are first described. Then, the use of dendritic TPA chromophores for light harvesting, photopolymerization, optical power limitation, cell imaging, singlet oxygen generation, and photodynamic therapy is described. This review thus proposes an overview of the properties and possible applications of two-photon absorbing dendrimers

The Chemistry of P=N−P=X (X=S, O, NR) Linkages for the Synthesis of Dendritic Structures

International audienceThe Staudinger reaction between a phosphine and an azide, applied to phosphorus azides, has been used for the synthesis of a large variety of dendritic structures, incorporating P=N−P=X moieties (X = mainly S, but also O and N−R). Conjugation of the P=N bond with the P=X bond greatly stabilizes the P=N bond. Highly branched structures such as dendrons, dendrimers, Janus dendrimers, layered dendrimers, surface-block dendrimers, and diverse other dendritic structures incorporating such linkage have been elaborated. Accelerated methods of synthesis of dendrimers are also based on the Staudinger reaction. A versatile reactivity was observed exclusively on the sulfur atom of P=N−P=S linkages, such as alkylation or complexation. Alkylation on S induces a weakening of the strength of the P=S bond, which can be easily cleaved to generate phosphines able to react in Staudinger reactions inside the structure of dendrimers, thus affording highly sophisticated dendritic structures

Dendritic Pyridine-Imine Copper Complexes as Metallo-Drugs

International audienceSince the discovery of cisplatin in the 1960s, the search for metallo-drugs that are more efficient than platinum complexes with negligible side effects has attracted much interest. Among the other metals that have been examined for potential applications as anticancer agents is copper. The interest in copper was recently boosted by the discovery of cuproptosis, a recently evidenced form of cell death mediated by copper. However, copper is also known to induce the proliferation of cancer cells. In view of these contradictory results, there is a need to find the most suitable copper chelators, among which Schiff-based derivatives offer a wide range of possibilities. Gathering several metal complexes in a single, larger entity may provide enhanced properties. Among the nanometric objects suitable for such purpose are dendrimers, precisely engineered hyperbranched macromolecules, which are outstanding candidates for improving therapy and diagnosis. In this review article, we present an overview of the use of a particular Schiff base, namely pyridine–imine, linked to the surface of dendrimers, suitable for complexing copper, and the use of such dendrimer complexes in biology, in particular against cancers