An unusual pituitary pathology

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The importance of the exposome and allostatic load in the planetary health paradigm

In 1980, Jonas Salk (1914-1995) encouraged professionals in anthropology and related disciplines to consider the interconnections between "planetary health," sociocultural changes associated with technological advances, and the biology of human health. The concept of planetary health emphasizes that human health is intricately connected to the health of natural systems within the Earth's biosphere; experts in physiological anthropology have illuminated some of the mechanisms by which experiences in natural environments (or the built environment) can promote or detract from health. For example, shinrin-yoku and related research (which first emerged from Japan in the 1990s) helped set in motion international studies that have since examined physiological responses to time spent in natural and/or urban environments. However, in order to advance such findings into planetary health discourse, it will be necessary to further understand how these biological responses (inflammation and the collective of allostatic load) are connected to psychological constructs such as nature relatedness, and pro-social/environmental attitudes and behaviors. The exposome refers to total environmental exposures-detrimental and beneficial-that can help predict biological responses of the organism to environment over time. Advances in "omics" techniques-metagenomics, proteomics, metabolomics-and systems biology are allowing researchers to gain unprecedented insight into the physiological ramifications of human behavior. Objective markers of stress physiology and microbiome research may help illuminate the personal, public, and planetary health consequences of "extinction of experience." At the same time, planetary health as an emerging multidisciplinary concept will be strengthened by input from the perspectives of physiological anthropology.Peer reviewe

Détermination d'un profil de vitesse en mouvement turbulent par la méthode du potentiel local

Nous utilisons la méthode du potentiel local de Glansdorff et Prigogine pour déterminer par voie d'analyse numérique une loi approchée de distribution des grandeurs moyennes dans la section d'un fluide incompressible en mouvement turbulent. Nous envisageons le cas simple d'un écoulement à deux dimensions maintenu entre deux plans lisses indéfinis et nous comparons les résultats fournis par divers procédés d'approximation. Il apparaît que des fonctions d'essai ne satisfaisant pas aux conditions aux limites, sinon asymptotiquement, peuvent, dans le cas présent, donner des résultats beaucoup plus rapidement convergents qu'à l'aide de fonction y satisfaisant et qui se comparent favorablement aux résultats expérimentaux. D'autre part, la méthode des éléments finis permet d'obtenir un accord parfait avec les résultats expérimentaux.Flandroy P., Platten Jean Karl. Détermination d'un profil de vitesse en mouvement turbulent par la méthode du potentiel local. In: Bulletin de la Classe des sciences, tome 63, 1977. pp. 686-712

Control of the biodegradation rate of poly(DL-lactide) microparticles intended as chemoembolisation materials

There is an interest in polylactide microspheres that biodegrade within a few days, particularly for chemoembolization applications. For this purpose, two poly(DL-lactide) samples of a very different molecular weight have been combined. The basic concept relies upon the capability of the high molecular weight component (Mn: 65 000) to provide the microspheres with a high mechanical strength, whereas the low molecular weight component (Mn: 3500) should decrease the particle lifetime dramatically. It has been shown that changing the weight ratio of these two components is an efficient way to control the kinetics of the in vitro degradation of poly(DL-lactide) microspheres on the expected time scale. The microspheres have been prepared by the oil-in-water emulsion/evaporation process, and their final polymer content has been compared to the initial composition of the oil phase. They have also been analyzed by differential scanning calorimetry to know whether the two polymers form a monophase blend or not. Kinetics of the in vitro biodegradation has been estimated from the decrease in molecular weight of the constitutive poly(DL-lactide)s, the time-dependency of the microsphere weight and the observation of changes in the morphology by scanning electron microscopy. Progress in the hydrolysis of the ester groups has also been reckoned from the increasing acidity of the incubation medium and associated with the polymer

Contribution of macromolecular engineering for the design of new colloidal and particular vectors for drugs targeting

peer reviewedVarious colloidal and microparticular vector have been tailored during the last few years in order to promote the transport , the protection and the orientation of the drug towards its pharmacological target. The aim of the paper is to give some insight about the contribution of the macromolecular engineering for the development of two vectors : microparticles of a control biodegradation rate designed for the chemoembolization of hepatocarcinoma , amphiphile copolymeric micelles able to transport drug within the targeted cells. Starting from a synthetic polymer : polylactide, degradation rate caracteristics , and functionalities can be tailored for the intended applications. One of the major problems , and largely underestimated in the past , for the successfull design of polymeric carrier is to take into account the interaction of proteins with polymer surfaces.Différents vecteurs colloïdaux et microparticulaires ont été étudiés ces dernières années pour transporter, protéger et orienter des médicaments vers des cibles pharmacologiques particulières Le sujet de cette communication est d'illustrer l'apport de la chimie macromoléculaire pour la conception de deux types de vecteurs : des microparticules de vitesse de biodégradation contrôlée destinées à la chimioembolisation d'hépatocarcinomes, des vecteurs micellaires susceptibles de véhiculer un principe actif jusqu'au sein de la cellule cible. La conception de ces deux matériaux a été réalisée au départ d'un polymère de synthèse : le polylactide Un des problèmes clés pour la mise au point de ces vecteurs suppose de connaître et maîtriser les interactions spécifiques ou non procédant à l'interface polymère - milieu biologique

Clinical applications of microspheres in embolization and chemoembolization: a comprehensive review and perspectives

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