Biomedical subjects

Véronique Lapeyre

Publications and source records attributed to Véronique Lapeyre.

3 recordsLinked to original sources

PubMed2006

Monodispersed glucose-responsive microgels operating at physiological salinity.

Monodispersed poly(N-isopropylacrylamide) submicrometric microgels modified with a phenylboronic acid (PBA) derivative have been synthesized by precipitation polymerization. Particles with a well-controlled size and adjustable composition were obtained. These particles were found to be glucose responsive at a pH close to the pKa of the PBA derivative, with a swelling degree proportional to the concentration of glucose. In addition, the response to glucose was found to strongly depend on the initial state of the microgel, which depended itself on the initial temperature and the functionalization degree of the particle. This result explained the fundamental difference in the behavior of PBA-poor particles and rich ones in the presence of electrolyte. Interestingly, the latter exhibited a high swelling ratio in the presence of glucose at physiological electrolyte concentration. These particles may serve as building blocks for the design of colorimetric sensors based on the light diffraction of colloidal crystals.

Amides↗

PubMed2005

Full verification of the liquid exclusion-adsorption chromatography theory using monolithic capillary columns.

Capillary electrochromatography (CEC) was used to separate alkyl phenol ethoxylates (APEs) as model diblock copolymers, with monolithic polymers as stationary phases. The order of elution indicate that the two polymer blocks follow distinct chromatographic modes: size-exclusion for the poly(oxyethylene) group and adsorption interaction for the alkyl part. Therefore, our experimental results were compared to the theory describing liquid exclusion-adsorption chromatography (LEAC). They were found in perfect agreement with the theory, which turned to be verified for the first time over the full range of polymer lengths.

Acetophenones↗

PubMed2002

Feasibility of and interest in combined endoscopic ultrasonography and biliary drainage in unexplained acute biliopancreatic disorders.

Combined endoscopic ultrasonography and duodenal bile drainage for microscopic bile examination was prospectively evaluated in patients with unexplained acute biliopancreatic disorders defined as follows: isolated biliary-type pain (group 1), biliary-type pain and elevated transaminases (group 2), or acute pancreatitis (group 3). All patients had prior negative transabdominal ultrasonography. Endoscopic ultrasonography and bile drainage were combined under anesthesia during the same procedure. Combined endoscopic ultrasonography and bile drainage was feasible without any complication in the 48 patients studied. Biliary lithiasis was diagnosed in 20 patients (42%), 5 in group 1 (38%), 7 in group 2 (39%), and 8 in group 3 (47%). Endoscopic ultrasonography and microscopic bile examination were positive respectively in 17 (36%) and in 13 (27%) patients. In conclusion, combined endoscopic ultrasonography and bile drainage for microscopic bile examination is a simple procedure. Biliary lithiasis is diagnosed in a high proportion of patients with unexplained acute biliopancreatic disorders.

Acute Disease↗