Umbilical VeinsVeinsUmbilical ArteriesHuman Umbilical Vein Endothelial CellsEndothelium, VascularSaphenous VeinPortal VeinVaricose VeinsEndothelial CellsCells, CulturedHernia, UmbilicalFemoral VeinPulmonary VeinsJugular VeinsFetal BloodUmbilicusMesenteric VeinsRenal VeinsIliac VeinPregnancyHepatic VeinsUltrasonography, PrenatalPopliteal VeinCell AdhesionEndotheliumNeovascularization, PhysiologicE-SelectinSubclavian VeinVascular Cell Adhesion Molecule-1Splenic VeinCord Blood Stem Cell TransplantationCerebral VeinsVascular Endothelial Growth Factor AUltrasonography, DopplerIntercellular Adhesion Molecule-1Cell MovementRNA, MessengerRetinal VeinUmbilical CordNitric Oxide Synthase Type IIIAzygos VeinBrachiocephalic VeinsFetal DiseasesFetal Growth RetardationInfant, NewbornAngiogenesis InhibitorsFetusBlood Flow VelocityGestational AgeNeovascularization, PathologicTumor Necrosis Factor-alphaAxillary VeinThrombinTime FactorsPlacental CirculationRetinal Vein OcclusionCell Adhesion MoleculesDose-Response Relationship, DrugUltrasonography, Doppler, ColorCell ProliferationEpoprostenolNitric OxidePlacentaSignal TransductionVena Cava, InferiorCulture Media, ConditionedPulsatile FlowSingle Umbilical ArteryVascular Endothelial Growth Factor Receptor-2Stress, MechanicalInterleukin-1von Willebrand FactorMaternal-Fetal ExchangeCell DivisionVenous ThrombosisCell LineCell SurvivalGene Expression RegulationUltrasonography, Doppler, PulsedChorioallantoic MembraneUp-RegulationThromboplastinEndothelial Growth FactorsPhosphorylationHistamineAortaInterleukin-8Vascular Endothelial Growth FactorsCoculture TechniquesReverse Transcriptase Polymerase Chain ReactionEnzyme InhibitorsLymphokinesAntigens, CDFetal HeartBlotting, WesternNF-kappa BMonocytesUrachal CystApoptosisAngiogenesis Inducing Agents