Surfactant phosphatidylcholine half-life and pool size measurements in premature baboons developing bronchopulmonary dysplasia

Because minimal information is available about surfactant metabolism in bronchopulmonary dysplasia, we measured half-lives and pool sizes of surfactant phosphatidylcholine in very preterm baboons recovering from respiratory distress syndrome and developing bronchopulmonary dysplasia, using stable isotopes, radioactive isotopes, and direct pool size measurements. Eight ventilated premature baboons received (2)H-DPPC (dipalmitoyl phosphatidylcholine) on d 5 of life, and radioactive (14)C-DPPC with a treatment dose of surfactant on d 8. After 14 d, lung pool sizes of saturated phosphatidylcholine were measured. Half-life of (2)H-DPPC (d 5) in tracheal aspirates was 28 +/- 4 h (mean +/- SEM). Half-life of radioactive DPPC (d 8) was 35 +/- 4 h. Saturated phosphatidylcholine pool size measured with stable isotopes on d 5 was 129 +/- 14 micro mol/kg, and 123 +/- 11 micro mol/kg on d 14 at autopsy. Half-lives were comparable to those obtained at d 0 and d 6 in our previous baboon studies. We conclude that surfactant metabolism does not change during the early development of bronchopulmonary dysplasia, more specifically, the metabolism of exogenous surfactant on d 8 is similar to that on the day of birth. Surfactant pool size is low at birth, increases after surfactant therapy, and is kept constant during the first 2 wk of life by endogenous surfactant synthesis. Measurements with stable isotopes are comparable to measurements with radioactive tracers and measurements at autopsy

Pour une science ouverte réaliste, équilibrée et respectueuse de la liberté académique : rapport

L’Office parlementaire d’évaluation des choix scientifiques et technologiques (OPECS) a adopté le rapport « Pour une science ouverte réaliste, équilibrée et respectueuse de la liberté académique » présenté à l’Assemblée nationale française (9 mars 2022). Il offre un point de vue parlementaire et une série de recommandations propres à susciter la discussion et les échanges sur une problématique d’importance pour les bibliothèques universitaires

Copolymère hydrophobe visible en IRM

The invention relates to a hydrophobic thermoplastic copolymer which is in particular of use for manufacturing and/or coating medical devices, in particular implantable medical devices, characterized in that it is obtained by copolymerization, and in that it comprises at least one first monomer unit and at least one second monomer unit onto which is grafted a paramagnetic-ion-chelating ligand which can complex with such a paramagnetic ion or a paramagnetic-ion-chelating ligand which is complexed with such a paramagnetic ion, wherein the second monomer unit is grafted in sufficient amount for the copolymer to be visible in magnetic resonance imaging when it is complexed with said paramagnetic ion. The invention also relates to a method for obtaining said hydrophobic thermoplastic copolymer