Why RNA and DNA Have Different Structures -- Regulatory RNAs as Mediators of Virulence Gene Expression in Bacteria -- Regulatory RNAs in Mammals -- Aminoglycoside Interactions with RNAs and Nucleases -- High-Throughput RNA Interference in Functional Genomics -- Antiviral Applications of RNAi -- RNA Interference: Its Use as Antiviral Therapy -- Gene Silencing of Virus Replication by RNA Interference -- Progress in the Development of Nucleic Acid Therapeutics -- Screening and Determination of Gene Function Using Randomized Ribozyme and siRNA Libraries -- Ribozymes and siRNAs: From Structure to Preclinical Applications -- Strategies to Identify Potential Therapeutic Target Sites in RNA -- Oligonucleotide-Based Antiviral Strategies -- Gene-Expressed RNA as a Therapeutic: Issues to Consider, Using Ribozymes and Small Hairpin RNA as Specific Examples -- RNA Aptamers: From Basic Science Towards Therapy -- RNA Aptamers Directed Against Oligosaccharides -- Aptamer-Based Biosensors: Biomedical Applications -- Application of Aptamers in Therapeutics and for Small-Molecule Detection -- RNA Aptamers as Potential Pharmaceuticals Against Infections with African Trypanosomes -- RNA Targeting Using Peptide Nucleic Acid -- Locked Nucleic Acid: High-Affinity Targeting of Complementary RNA for RNomics -- Engineering RNA-Based Circuits -- Selection of RNase-Resistant RNAs.