For decades retroviruses have been riding the crest of a wave of experimental research directed toward the identification of an infectious agent of human neoplastic diseases. In the early 1970s, several scientists successfully demonstrated the presence of retroviruses in numerous animal species and proved their etiological role in some related diseases. Corresponding findings in humans were somewhat discouraging. Although financial support for this line· of research declined, a few dedicated retrovirologists survived and continued to collect more biological information and technological expertise that opened a new approach to the search for a human retrovirus. The rewards came with the discovery that the genes responsible for neoplastic transformation (oncogenes) are of cellular origin and can be shuttled about by retroviruses, and with the identification of a new family of Human T-cell Lymphotrophic retroViruses (HTLV) from patients with diseases ranging from leukemia to the acquired immunodeficiency syndrome (AIDS). An understanding of the role and significance of retroviruses in human pathology requires basic knowledge of the major animal systems studied. With this perspective in mind, we present here a survey that includes general overviews, minireviews on each animal system studied with selected experimental reports and, finally, a stimulating review of the field of human retrovirology by many of the pioneer scientists who created it. We are especially grateful to Profs. C. A. Romanzi and G. C. Schito for promoting the organization of the Symposium. On behalf of the Sym posium Committee, we thank E. Soeri, L. Casarino, G. P. Gesu, M.

Inhalt
Introduction: The Role of Retroviruses.- Opening Remarks.- Retroviruses in Neoplasia Yesterday, Today, and Tomorrow.- The Role of Retroviruses in Nature.- W. P. Rowe Memorial Lecture.- Changing Dogmas in Retrovirology.- Section 1 Retroviruses and the Murine Model System.- The Biology of Endogenous Leukemia Viruses: A Study of the DBA/2 Mouse.- Murine Xenotropic Retroviruses in the Computer Age.- Viral and Nonviral Mammary Tumorigenesis.- The Proviral Genome of Radiation Leukemia Virus: Molecular Cloning, Nucleotide Sequence of Its Long Terminal Repeat, and Integration in Lymphoma Cell DNA.- Metastatic Potential of Friend Leukemia Cells: Fibronectin Induces Specific Arrest, Survival, and Growth of FLC in Liver of DBA/2 Mice.- The Envelope Gene of Mammalian Retroviruses: Analysis of Its Structure Reveals Specific Recombination Signals.- The Major Histocompatibility Complex (H-2) of the Mouse Influences the Phenotype of Murine Leukemia Virus-Induced Lymphomas.- Mouse Mammary Tumor Virus (MMTV) Morphology in the Gastrointestinal Lumen of Suckling Mice.- Murine Retroviruses: An Alternative Screening Approach for Antiviral Drug Research.- Section 2 Retroviruses and the Vertebrate Model System.- Retroviruses and Oncogenes in Rats.- Target Cells for Avian Leukemia Viruses Revisited.- Feline Retroviruses.- Bovine Leukemia Virus, A Distinguished Member of the Human TLymphotropic Viruses Family.- Association of Ultraviolet-Induced Retrovirus Expression with Anchorage-Independent Survival in Rat Embryo Cells.- Participation of 7S L RNA in Reverse Transcription by an Avian Retrovirus.- Different Retroviruses Show Different Susceptibilities to 2-Deoxy-D-glucose.- A Comparative Study of Bovine Leukemia Virus (BLV) Detection Methods.- Structural and Functional Heterogeneity among TypeD Retroviruses.- Retroviruses and Oncogenes in the Rat Sarcoma Galliera: An old Tumor as a Unique Model System.- Section 3. Retroviruses and Human Pathology.- Molecular Biology of Viruses of the HTLV Family.- Activation of Retroviral Genes in Human Reproductive Tissues and Tumors.- Retrovirus and AIDS.- Human T-Cell Leukemia (Lymphotropic) Retroviruses: The HTLV Family and Their Role in Leukemias, Lymphomas, and AIDS.- The Organization of Mouse Mammary Tumor Virus-Related Sequences in Human Cellular DNA.- Close Structural Similarities Between the LTRs of Bovine Leukemia and Human T-Cell Leukemia Viruses.- Analysis and Immunological Properties of Lymphadenopathy- Associated Virus (LAV) Structural Proteins.- RNA Viruses and Lymphocyte Immune Functions.- Anti HTLV-III and Anti T-Cell Antibodies in AIDS and ARC Patients.- Seroepidemiological Study of Lymphadenopathy-Associated Virus, by ELISA, in Acquired Immunodeficiency Syndrome.- IgG Antibodies to SAIDS-D Virus Associated Antigens in Patients with AIDS and at Risk for AIDS.- Is a Retrovirus-Like Particle Expressed at a Specific Stage During Human Oocyte Maturation?.- Psoriasis A Retrovirus Disease?.- Purification and Characterization of a High Molecular Weight Human Milk Ribonuclease: Its Potential use for Diagnosis and Prognosis of Human Mammary Neoplasia.- The Role of Retroviruses in AIDS and Slow Infections.- Section 4. Retroviruses and Oncogenes.- Retroviruses with Two Oncogenes.- Molecular Assays for Detection Of ras Oncogenes in Human and Animal Tumors.- The raf Oncogene.- Role of Retroviral Oncogenes in the Attachment of Cells to Natural Substrata.- Amplification of Cellular Oncogenes in Colon and Lung Cancer Cells.- The Nucleotide Sequence of the erbA Gene of Avian Erythroblastosis Virus Appears Unrelated toOther Known Oncogenes.- Characterization of a Human Osteosarcome Oncogene.- Coordinated Regulation of the c-myc Gene and a Tumor-related Multigenic Set in Human Neoplastic Cells Treated with Differentiation Inducers Including Tumor Promoters.- Transcripts of c-fes Oncogene are Present at Detectable Levels in Total Cellular RNA of Human Myeloid but not Lymphoid Normal and Neoplastic Cells.- Heterogeneity of Human Normal and Leukemic Cells of Lymphoid and Myeloid Lineage in Respect to the Expression Of c-myc and c-myb Mrna Transcripts.- Detection Of c-myc, c-myb and c-fes Oncogene Transcripts in Human Myeloid and Lymphoid Normal and Leukemic Cells by In Situ Hybridization.