GanciclovirAntiviral AgentsThymidine KinaseCytomegalovirus InfectionsCytomegalovirus RetinitisCytomegalovirusFoscarnetAcyclovirGenetic TherapySimplexvirusGenes, Transgenic, SuicideProdrugsRetinitisPhosphotransferases (Alcohol Group Acceptor)Herpesvirus 1, HumanGenetic VectorsGliosarcomaOrgan TransplantationBystander EffectAIDS-Related Opportunistic InfectionsOrganophosphonatesAdministration, OralAntimetabolitesTransplantation, HomologousViremiaAdenoviridaeCytosineDrug Resistance, ViralRibonucleosidesInjections, IntravenousVitreous BodyOrganophosphorus CompoundsDNA, ViralAcquired Immunodeficiency SyndromeDrug ImplantsTumor Cells, CulturedBone Marrow TransplantationGene Transfer TechniquesOpportunistic InfectionsDimercaprolHerpesvirus 6, HumanTransduction, GeneticGuaninePneumonia, ViralTransplantation