Umbilical VeinsVeinsUmbilical ArteriesHuman Umbilical Vein Endothelial CellsEndothelium, VascularSaphenous VeinPortal VeinVaricose VeinsEndothelial CellsCells, CulturedFemoral VeinHernia, UmbilicalPulmonary VeinsJugular VeinsFetal BloodUmbilicusMesenteric VeinsRenal VeinsIliac VeinPregnancyHepatic VeinsUltrasonography, PrenatalPopliteal VeinCell AdhesionEndotheliumNeovascularization, PhysiologicMolecular Sequence DataSupine PositionE-SelectinSubclavian VeinProne PositionVascular Cell Adhesion Molecule-1Splenic VeinCerebral VeinsCord Blood Stem Cell TransplantationRNA, MessengerVascular Endothelial Growth Factor ACell MovementUltrasonography, DopplerIntercellular Adhesion Molecule-1Base SequenceTime FactorsRetinal VeinAmino Acid SequenceInfant, NewbornBrachiocephalic VeinsUmbilical CordNitric Oxide Synthase Type IIIFetal DiseasesAzygos VeinFetusBlood Flow VelocityGestational AgeFetal Growth RetardationAngiogenesis InhibitorsTumor Necrosis Factor-alphaNeovascularization, PathologicThrombinDose-Response Relationship, DrugAxillary VeinCell Adhesion MoleculesPlacental CirculationRetinal Vein OcclusionCell LineUltrasonography, Doppler, ColorSignal TransductionCell ProliferationPlacentaNitric OxideVena Cava, InferiorEpoprostenolGene Expression RegulationStress, MechanicalPulsatile FlowCulture Media, ConditionedKineticsRecombinant ProteinsSingle Umbilical ArteryCell DivisionInterleukin-1von Willebrand FactorVascular Endothelial Growth Factor Receptor-2PhosphorylationMaternal-Fetal ExchangeCell SurvivalVenous ThrombosisUltrasonography, Doppler, PulsedPostureUp-RegulationReverse Transcriptase Polymerase Chain ReactionBinding SitesThromboplastinChorioallantoic MembraneEnzyme InhibitorsBlotting, WesternGene ExpressionAortaTransfectionEndothelial Growth FactorsHistamine