Avian Leukosis

7.Avian sarcomas: immune responsiveness and pathology.- 1. Introduction.- 2. Cellular transformation by avian sarcoma viruses.- 3. Viral-associated antigens.- 4. ASV-induced pathogenesis and immunosuppression.- 5. Development of anti-tumor immunity in tumor-bearing hosts.- 6. The immunogenicity of retroviral envelope glycoprotein.- 7. Characteristics of tumor cell growth in vivo and in vitro.- 8.Virus-cell interactions of avian sarcoma and defective leukemia viruses.- 1. Introduction.- 2. Avian sarcoma viruses.- 3. Pathogenic effects of avian sarcoma viruses in vivo.- 4. Transforming effects of avian sarcoma viruses in vitro.- 5. Defective avian leukemia viruses.- 6. Conclusions and future trends.- 9.The pathogenesis and pathology of neoplasms caused by avian leukosis viruses.- 1. Introduction.- 2. Virus classification.- 3. Factors affecting the pathogenic response.- 4. Classification of leukemias and leukoses.- 5. Other tumors and tumorous conditions.- 6. Non-neoplastic conditions.- 7. Transplantability and development of cell lines.- 8. Lymphoid leukosis.- 9. Erythroblastosis.- 10. Myeloblastosis.- 11. Nephroblastomatosis.- 12. Osteopetrosis.- 13. Concluding remarks.- 10.Differential diagnosis of lymphoid leukosis.- 1. Introduction.- 2. Clinical signs.- 3. Etiology.- 4. Pathogenesis.- 5. Gross pathology.- 6. Microscopic pathology.- 7. Serological and immunological techniques.- 11.Laboratory diagnostic procedures for detecting avian leukosis virus infections.- 1. Introduction.- 2. Collection and handling of specimens.- 3. In vivo assay of RSV and ALV.- 4. In vitro assay of RSV and ALV.- 5. Production of virus stocks and antiserum.- 6. Tests based on interaction between ALV and RSV.- 7. Tests for ALV based on detection of group-specific antigens.- 8. Detection and distribution of viral antigens in host tissues.- 9. Detection of antibody against subgroup- and group-specific antigens.- 10. Concluding remarks.- 12.Influences of avian leukosis virus infection on production and mortality and the role of genetic selection in the control of lymphoid leukosis.- 1. Introduction.- 2. Frequency of ALV infection.- 3. Effects of ALV infection on production and mortality.- 4. Prospects for the future.- 13.Approaches to control avian lymphoid leukosis.- 1. Introduction.- 2. Detection of congenital ALV transmission.- 3. Prevention of horizontal virus exposure.- 4. LL control by elimination of ALV shedding hens.- 5. Manipulation of the immune response.- 6. Genetic resistance.- 7. Concluding remarks.