Patient SelectionLeukoencephalopathy, Progressive MultifocalMultiple Sclerosis, Relapsing-RemittingIntegrin alpha4Antibodies, Monoclonal, HumanizedJC VirusSelection, GeneticMultiple SclerosisIntegrin alpha ChainsAntibodies, MonoclonalTreatment OutcomeImmunologic FactorsIntegrin alpha4beta1Interferon-betaClorazepate DipotassiumCell Migration InhibitionRecurrenceClinical Trials as TopicImmune Reconstitution Inflammatory SyndromeMagnetic Resonance ImagingTeaching RoundsImmunosuppressive AgentsPlasma ExchangePropylene GlycolsRetrospective StudiesOpportunistic InfectionsFollow-Up StudiesTime FactorsPostoperative ComplicationsGadoliniumCrohn DiseaseDisease ProgressionCentral Nervous SystemDrug HypersensitivityPrognosisFetal TherapiesMethylprednisoloneRisk AssessmentLeukocytosisComparative Effectiveness ResearchPredictive Value of TestsModels, GeneticRisk FactorsProspective StudiesSurvival RateEvolution, MolecularReoperationBrainFatigueQuality of LifeLongitudinal StudiesPeptidesAntineoplastic AgentsCohort StudiesSurvival AnalysisInfusions, IntravenousBiological EvolutionTomography, X-Ray ComputedRandomized Controlled Trials as TopicChemotaxis, LeukocyteGenetic VariationClinical Trials, Phase I as TopicMutationSelection BiasCell Adhesion MoleculesDouble-Blind MethodPreoperative CareHeart Valve Prosthesis ImplantationAmbulatory Surgical ProceduresStrokeNeoplasm Recurrence, LocalSurgical Procedures, Minimally InvasiveCombined Modality TherapyProsthesis DesignMarkov ChainsBiological MarkersHeart FailureCardiac CatheterizationReproducibility of ResultsDNA, ViralMolecular Sequence DataLiver NeoplasmsCD4-Positive T-LymphocytesCardiac Resynchronization TherapyLaparoscopyIntraoperative ComplicationsMultivariate AnalysisNeoplasmsT-LymphocytesDisability EvaluationEndoscopyNeoplasm StagingAge FactorsHeart-Assist DevicesAlgorithmsProstheses and ImplantsGenetics, PopulationAngioplastyCryosurgeryAortic Valve Stenosis