Heterocyclic Compounds, Bridged-RingHIV InfectionsHIV SeropositivityDrug Screening Assays, AntitumorXenograft Model Antitumor AssaysAntineoplastic AgentsHIV SeroprevalenceCell Line, TumorHIV SeronegativityLeukemia P388Antibiotics, AntineoplasticMice, NudeSarcoma 180Neoplasms, ExperimentalNeoplasm Transplantation