Antoine Malek

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OBJECTIVE Mesenchymal stem cells (MSCs) have a broad differentiation potential. We aimed to determine if MSCs are present in fetal membranes and placental tissue and to assess their potential to differentiate into neurogenic and mesodermal lineages. STUDY DESIGN MSCs isolated from first and third trimester chorion and amnion and first trimester chorionic(More)
PROBLEM We determined the evolution of the maternal-fetal transport of immunoglobulins during human pregnancy. METHOD Paired blood samples were collected between 17-41 weeks of gestation (WG) by puncture of a peripheral maternal vein and by cordocentesis (17-36 WG, n = 91) or directly at delivery (37-41 WG n = 16) from the umbilical vein. Additional(More)
BACKGROUND Humans have been exposed to fine and ultrafine particles throughout their history. Since the Industrial Revolution, sources, doses, and types of nanoparticles have changed dramatically. In the last decade, the rapidly developing field of nanotechnology has led to an increase of engineered nanoparticles with novel physical and chemical properties.(More)
OBJECTIVE This study was undertaken to isolate and characterize multipotent mesenchymal stem cells from term human placenta (placenta-derived mesenchymal stem cells, PD-MSCs). STUDY DESIGN Sequential enzymatic digestion was used to isolate PD-MSCs in which trypsin removes the trophoblast layer, followed by collagenase treatment of remaining placental(More)
OBJECTIVE The transport of immunoglobulin G and its subclasses 1 to 4 was investigated in the in vitro-perfused isolated cotyledon of the human placenta. STUDY DESIGN An in vitro system with separate perfusion of the villous capillary system (fetal compartment) and the corresponding intervillous space (maternal compartment) was set up in an isolated(More)
The transplacental flux of glucose together with the consumption by the tissue was studied in human term placenta using the dual in vitro perfusion of an isolated cotyledon. The effect of different transplacental glucose gradients going either from the maternal to the foetal side or in the opposite direction was tested. A linear correlation between uptake(More)
Human term-placental culture techniques such as villous explant or dual perfusion are commonly used to study trophoblast function under control and experimentally manipulated conditions. We have compared trophoblast viability during perfusion and in explants cultured under various conditions by monitoring glucose consumption, protein synthesis and(More)
Pre-eclampsia is a pregnancy-associated multi-system disorder of unknown etiology, characterized by damage to the maternal endothelium. The latter facet has been suggested to be mediated in part by elevated shedding of inflammatory placental syncytiotrophoblast micro-particles (STBM) into the maternal circulation. In this study, we have examined STBM(More)
There is clear evidence that the placenta produces leptin. However, it is still unclear to what extent leptin is released into the maternal and the fetal circulation. The aim of our study was to determine placental leptin release rates into these 2 compartments. In 10 term placentas, using dual in vitro perfusion of an isolated cotyledon, concentrations of(More)
Oxytocin (OX) has been suggested as a signal for parturition. Although OX is produced by both mother and fetus, concentrations are higher in umbilical than maternal blood. In addition, umbilical artery OX concentrations (15-40 pg/ml) are higher than umbilical vein (4-12 pg/ml) and maternal (1-10 pg/ml) concentrations. The umbilical A-V difference suggests(More)