Multiple SclerosisCentral Nervous System DiseasesCentral Nervous System NeoplasmsCentral Nervous SystemDemyelinating Autoimmune Diseases, CNSCentral Nervous System Viral DiseasesCentral Nervous System InfectionsEncephalitis, ViralDisease Models, AnimalBrain DiseasesAIDS Dementia ComplexEncephalitisBrainBlood-Brain BarrierModels, AnimalNasopharyngeal NeoplasmsMeningeal NeoplasmsCerebrospinal FluidInjections, SpinalDemyelinating DiseasesLymphoma, Non-HodgkinMeningoencephalitisMethotrexateMicrogliaEncephalomyelitis, Autoimmune, ExperimentalAstrocytesVincristineNeuronsNiemann-Pick DiseasesMice, Inbred C57BLBrain NeoplasmsSimian Acquired Immunodeficiency SyndromeNiemann-Pick Disease, Type CNeurodegenerative DiseasesPrednisoneSpinal CordCyclophosphamidePrecursor Cell Lymphoblastic Leukemia-LymphomaAntineoplastic Combined Chemotherapy ProtocolsMice, TransgenicSimian immunodeficiency virusCells, CulturedDoxorubicinNuclear PoreCombined Modality TherapyPrognosisRetrospective Studies