Umbilical VeinsVeinsHuman Umbilical Vein Endothelial CellsUmbilical ArteriesEndothelium, VascularSaphenous VeinEndothelial CellsCells, CulturedPortal VeinVaricose VeinsHernia, UmbilicalFemoral VeinPulmonary VeinsJugular VeinsFetal BloodCell AdhesionUmbilicusMesenteric VeinsRenal VeinsE-SelectinNeovascularization, PhysiologicIliac VeinPregnancyVascular Cell Adhesion Molecule-1Hepatic VeinsEndotheliumUltrasonography, PrenatalIntercellular Adhesion Molecule-1Popliteal VeinCell MovementVascular Endothelial Growth Factor AAngiogenesis InhibitorsUmbilical CordRNA, MessengerSubclavian VeinSplenic VeinTumor Necrosis Factor-alphaNeovascularization, PathologicCell Adhesion MoleculesCord Blood Stem Cell TransplantationCerebral VeinsNitric Oxide Synthase Type IIIUltrasonography, DopplerThrombinDose-Response Relationship, DrugTime FactorsRetinal VeinInfant, NewbornCell ProliferationAzygos VeinBrachiocephalic VeinsFetal DiseasesFetal Growth RetardationSignal TransductionInterleukin-1FetusBlood Flow VelocityGestational AgeCulture Media, ConditionedEpoprostenolAxillary VeinNitric OxidePlacental CirculationVascular Endothelial Growth Factor Receptor-2Retinal Vein OcclusionCell SurvivalCell LineStress, MechanicalCell Divisionvon Willebrand FactorGene Expression RegulationInterleukin-8Ultrasonography, Doppler, ColorCoculture TechniquesUp-RegulationChorioallantoic MembraneNeutrophilsPlacentaEndothelial Growth FactorsVena Cava, InferiorThromboplastinPhosphorylationVascular Endothelial Growth FactorsEnzyme InhibitorsBlotting, WesternMonocytesReverse Transcriptase Polymerase Chain ReactionApoptosisAngiogenesis Inducing AgentsAntigens, CDPulsatile FlowNF-kappa BSingle Umbilical ArteryLymphokinesAortaHistamineMaternal-Fetal ExchangeGene ExpressionRecombinant ProteinsVenous Thrombosis