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-SelectinVascular Cell Adhesion Molecule-1Subclavian VeinSplenic VeinCord Blood Stem Cell TransplantationCerebral VeinsVascular Endothelial Growth Factor ACell MovementRNA, MessengerIntercellular Adhesion Molecule-1Ultrasonography, DopplerTime FactorsInfant, NewbornRetinal VeinNitric Oxide Synthase Type IIIUmbilical CordFetal DiseasesAzygos VeinBrachiocephalic VeinsFetusAngiogenesis InhibitorsFetal Growth RetardationTumor Necrosis Factor-alphaBlood Flow VelocityGestational AgeNeovascularization, PathologicDose-Response Relationship, DrugSignal TransductionThrombinAxillary VeinCell Adhesion MoleculesPlacental CirculationRetinal Vein OcclusionCell ProliferationUltrasonography, Doppler, ColorNitric OxideCell LinePlacentaEpoprostenolVena Cava, InferiorGene Expression RegulationCulture Media, ConditionedPulsatile FlowStress, MechanicalSingle Umbilical ArteryCell DivisionCell SurvivalVascular Endothelial Growth Factor Receptor-2Interleukin-1PhosphorylationUp-Regulationvon Willebrand FactorMaternal-Fetal ExchangeReverse Transcriptase Polymerase Chain ReactionVenous ThrombosisBlotting, WesternApoptosisUltrasonography, Doppler, PulsedEnzyme InhibitorsChorioallantoic MembraneThromboplastinAortaCoculture TechniquesEndothelial Growth FactorsGene ExpressionAntigens, CDInterleukin-8HistamineVascular Endothelial Growth FactorsNF-kappa BEnzyme ActivationMonocytesFlow CytometryLymphokines