Search results for "PHIP"
showing 10 items of 438 documents
Could the acid-base status of Antarctic sea urchins indicate a better-than-expected resilience to near-future ocean acidification?
2015
Increasing atmospheric carbon dioxide concentration alters the chemistry of the oceans towards more acidic conditions. Polar oceans are particularly affected due to their low temperature, low carbonate content and mixing patterns, for instance upwellings. Calcifying organisms are expected to be highly impacted by the decrease in the oceans' pH and carbonate ions concentration. In particular, sea urchins, members of the phylum Echinodermata, are hypothesized to be at risk due to their high-magnesium calcite skeleton. However, tolerance to ocean acidification in metazoans is first linked to acid-base regulation capacities of the extracellular fluids. No information on this is available to dat…
Optically Active Hyperbranched Polyglycerol as Scaffold for Covalent and Noncovalent Immobilization of Platinum(II) NCN-Pincer Complexes. Catalytic A…
2004
New optically active hyperbranched polymers have been used as microenvironments as well as scaffolds for noncovalent and covalent immobilization of pincer platinum(II) complexes, respectively. The catalytic activity/selectivity of the incorporated platinum(II) complexes in these polymeric chiral supports was investigated. Chiral amphiphilic hyperbranched polyglycerols with core−shell “nanocapsules” structure, namely (−)-P(G40C160.5) (1) and (+)-P(G73C160.5) (2), have been prepared in two straightforward steps by ring-opening multibranching polymerization (ROMBP) of either (−)- or (+)-glycidol, resulting in (−)-PG40 (Mn = 3000, Mw/Mn = 1.3) or (+)-PG73 (Mn = 5500, Mw/Mn = 1.6), respectively.…
P(HPMA)-block-P(LA) copolymers in paclitaxel formulations: Polylactide stereochemistry controls micellization, cellular uptake kinetics, intracellula…
2012
In order to explore the influence of polymer microstructure and stereochemistry in biological settings, the synthesis, micellization, cellular fate and the use in paclitaxel formulations of poly(N-(2-hydroxypropyl)-methacrylamide)-block-poly(L-lactide) (P(HPMA)-block-P(LLA)) and poly(N-(2-hydroxypropyl)-methacrylamide)-block-poly(DL-lactide) block copolymers (P(HPMA)-block-P(DLLA)) were studied. To this end, P(HPMA)-block-P(lactide) block copolymers and their fluorescently labeled analogues were synthesized. The polymers exhibited molecular weights M-n around 20,000 g/mol with dispersities (D=M-w/M-n) below 1.3. In addition, the solution conformation of this new type of partially degradable…
Antiamphiphysin-positive stiff-person syndrome associated with small cell lung cancer
2006
The paraneoplastic amphiphysin(+) stiff-person syndrome (SPS) has so far only been described in women with breast adenocarcinoma. Here, we describe the rare case of a female patient with antiamphiphysin(+) SPS due to small cell cancer of the lung.
Methods of protein surface PEGylation under structure preservation for the emulsion-based formation of stable nanoparticles
2016
Proteins show remarkable versatility as multifunctional materials for therapeutic applications. They can be easily modified with the toolkit of bioorganic chemistry and are particularly attractive because of their degradability and biocompatibility. Herein, we evaluate different methods for the attachment of multiple PEG chains on the surface of the enzyme lysozyme. For this, we activated standard 2 kDa mPEG chains with four different electrophilic groups and tested their ability to react with different amino acids on the surface of our model protein. The aim was to find an effective and at the same time mild modification method that preserves the native structure and activity of the enzyme…
Sexual selection on male body size and assortative pairing in Gammarus pulex (Crustacea: Amphipoda): field surveys and laboratory experiments
2004
Variation in size-assortative pairing was studied in relation to sexual selection on male body size in the amphipod Gammarus pulex, using both transverse and longitudinal surveys of natural populations. In addition, the influence of male–male competition on size-assortative pairing was tested in the laboratory. In both surveys, the intensity of sexual selection was positive and significant for male body size but not for females, and size-assortative pairing was positive and significant. The magnitude of size-assortative pairing, however, varied significantly between populations. The magnitude of size-assortative pairing was positively correlated with the intensity of sexual selection on mal…
Origin of the natural variation in the storage of dietary carotenoids in freshwater amphipod crustaceans
2020
16 pages; International audience; Carotenoids are diverse lipophilic natural pigments which are stored in variable amounts by animals. Given the multiple biological functions of carotenoids, such variation may have strong implications in evolutionary biology. Crustaceans such as Gammarus amphipods store large amounts of these pigments and inter-population variation occurs. While differences in parasite selective pressure have been proposed to explain this variation, the contribution of other factors such as genetic differences in the gammarid ability to assimilate and/or store pigments, and the environmental availability of carotenoids cannot be dismissed. This study investigates the relati…
Interspecific differences in carotenoid content and sensitivity to UVB radiation in three acanthocephalan parasites exploiting a common intermediate …
2011
9 pages; International audience; Few endoparasite species are pigmented. Acanthocephalans are an exception however, with several species being characterised by yellow to orange colouration both at the immature (cystacanth) and adult stages. However, the functional and adaptive significance of carotenoid-based colourations in acanthocephalans remains unclear. One possibility is that the carotenoid content of acanthocephalan cystacanths acts as a protective device against ultra-violet radiation (UVR) passing through the translucent cuticle of their crustacean hosts. Indeed, acanthocephalans often bring about behavioural changes in their aquatic intermediate hosts that can increase their expos…
Development of polymer-based nanoparticles for Zileuton delivery to the lung : PMeOx and PMeOzi surface chemistry reduces interactions with mucins
2021
In this paper, two amphiphilic graft copolymers were synthesized by grafting polylactic acid (PLA) as hydrophobic chain and poly(2-methyl-2-oxazoline) (PMeOx) or poly(2-methyl-2-oxazine) (PMeOzi) as hydrophilic chain, respectively, to a backbone of α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA). These original graft copolymers were used to prepare nanoparticles delivering Zileuton in inhalation therapy. Among various tested methods, direct nanoprecipitation proved to be the best technique to prepare nanoparticles with the smallest dimensions, the narrowest dimensional distribution and a spherical shape. To overcome the size limitations for administration by inhalation, the nano-into-micr…
Mucoadhesive PEGylated inulin-based self-assembling nanoparticles: In vitro and ex vivo transcorneal permeation enhancement of corticosteroids
2019
Abstract As transcorneal drug delivery is still a challenge, the scope of the present study was to prepare useful nanosystems able to enhance transcorneal permeation/penetration of drugs. Moreover, this work aims to evaluate the effectiveness of inulin-based nanosystems in the specific field of ocular drug delivery and the effect of PEG chains to promote mucoadhesion, stability and transcorneal penetration/permeation enhancer effect of self-assembling nanoparticles in vitro (transwell systems and HCE) and ex vivo (Franz cells and bovine cornea). In particular, inulin was chosen as the starting natural polysaccharide polymer to design a novel amphiphilic derivative named INU-EDA-RA-PEG capab…