Archaebacteria and the Origin of the Eukaryotic Cytoplasm. With 6 Figures.- DNA Topoisomerases: Enzymes That Control DNA Conformation. With 3 Figures.- Defective-Interfering (DI) RNAs of Influenza Viruses: Origin, Structure, Expression, and Interference. With 10 Figures.- Biochemistry of Arenaviruses. With 6 Figures.- Structure and Diversity of the Influenza Virus Neuraminidase. With 14 Figures.- Indexed in Current Contents.