E. GRUNDMANN On behalf of the "Gesellschaft zur Bekampfung der Krebskrankheiten Nordrhein Westfalen e. V. " I welcome you in Dusseldorf. During these two days problems of oncogenesis have to be discussed. The participants have been selected with the inten tion of giving a review of the various fields which have some bearing on this topic. So you see here biochemists, cytologists, pathologists, immunologists, pharmacologists, virologists, and so on. Only by extensive cooperation of all scientists concerned in this field can this difficult problem of carcinogenesis ever be cleared up. Once the causal relations have been identified, we may have a reliable basis for cancer treat ment. Research on oncogenesis is of great interest, but it is only a part of the worldwide cancer campaign. It is our hope that this symposium will contribute towards helping the cancer patient. He is the center of all our efforts. Keeping this in mind - let us begin! General Problems of Carcinogenesis Molecular Mechanisms in Chemical Carcinogenesis P. N. MAGEE Covalent binding of metabolites of the hepatocarcinogenic azo dye p-dimethyl aminoazobenzene (DAB) to proteins of the livers of rats to which it had been ad ministered was observed by JAMES and ELIZABETH MILLER in 1947. Since then a large amount of work on the interaction of many other chemical carcinogens with cellular macromolecules has been reported.

Inhalt
Welcome and Introduction.- Welcome and Introduction.- General Problems of Carcinogenesis.- Molecular Mechanisms in Chemical Carcinogenesis.- Formation of Carcinogens From Precursors Occurring in the Environment: New Aspects of Nitrosamine-induced Tumorgenesis.- Intrauterine Induction of Cancer by the Experimental Application of Chemical Substances.- The Replication of RNA Tumor Viruses.- Differentiation of Tumor Cells Induction of Erythrocyte Membrane-Specific Antigens in Friend Leukemia Cells.- Immunosuppressive Effect of Friend's Mouse Leukaemia and Anti-Thymocyte Serum on Herpes Simplex Virus Infection.- Cytology and Histology of Cancer.- Precancerous Lesions and their Detection and Diagnosis.- Preinvasive Carcinoma.- Enzyme Histochemistry of Human Tumors. Indications of Differentiation and Functioning.- Electron Microscopy of Oncocytomas and Carcinoid Tumors.- The Histology of Rare Human Tumors and their Relationships to General Tumor Pathology.- Karyology of Carcinogenesis.- Chromosome Changes in Human Malignant Tumors: An Evaluation.- Chromosome Alteration in the Course of Serial Transplantions of Experimental Tumors and Aging of Tumor Stemline Cells.- Early Changes in Ploidy and Cytogenetics of Liver Cells After Diethylnitrosamine Treatment.- Models of Experimental Carcinogenesis.- Carcinogenesis in vitro.- Induction and Some Characteristics of Minimal Deviation and Other Transplantable Rat Hepatomas.- Carcinogen-induced Cellular Thesaurismoses and Neoplastic Cell Transformation.- Experimental Intestinal Carcinogenesis and Polyp Development in Rats and Mice.- Tumor Induction in the Rat Kidney with Different Doses of DEN (Diethylnitrosamine): Frequency, Latency and Morphology of the Tumors.- Respiratory Infections and the Pathogenesis of Lung Cancer.-Experimental Tumors of the Nervous System.- Tumor Organotropy of N-nitrosomethylurea under the Influence of Hormonal Contraceptives.- Role of Regional Lymph Nodes in Growth and Metastasis Formation of Methylcholanthrene-induced Sarcomas of Golden Hamsters.