Historically we have separated the disciplines of Chemistry and Biochemistry by recognizing that the distinguishing characteristic of Biochemistry is the catalysis of reactions by enzymes. Enzymes permit metabolic reactions which would otherwise require extremes of temperature, pressure or pH, often associated with Chemistry, to proceed under ambient conditions of the body. Under some conditions chemical reactions occur in vivo in which products of enzymatic reactions proceed to undergo further reactions non- enzymatically with cellular macromolecules. The results can often be seen as toxic or carcinogenic responses. The chemicals that initiate these reactions are termed "biological reactive intermediates. " The International Symposia on Biological Reactive Intermediates (BRI) began in 1975 at the University of Turku, Finland and have since convened at the University of Surrey, Guildford, The United Kingdom (1980), the University of Maryland, College Park, Maryland (1985), the University of Arizona, Tucson, Arizona (1990), the GSF Forschungszentrum and Technical University of Munich (1995) and, most recently, at the Universite Rene Descartes, Paris, France (2000). The Symposium was organized by an International Planning Committee co-chaired by P. Dansette (Paris, France) and TJ. Monks (Austin, Texas). The committee included: P. H. Beaune (Paris, France), M. De\aforge (Saclay, France), G. P. Gervasi (Pisa, Italy), G. G. Gibson (Guildford, UK), H. Greim (Munich, Germany), DJ. Jollow (Charleston, South Carolina), P. Moldeus (Sodertalje, Sweden), I. G. Sipes (Tucson, Arizona), R. Snyder PJ. van Bladderen (Zeist, The Netherlands). They were (Piscataway, New Jersey), and assisted by an International Scientific Program Advisory Committee which included: TJ.

Table of Contents:
Keynote Presentation; S. Orrenius, et al. Session I. Structure Activity Relationships for the Chemical Behaviour and Toxicity of Electrophilic Quinones/Quinone Methides; I.M.C.M. Rietjens, et al. Use of Structure-Activity Relationships for Probing Biochemical Mechanisms: Glutathione Transferase Zeta Conjugation of Haloacids; P.D. Swartz, A.M. Richard. Structure Toxicity Relationships - How Useful are They in Predicting Toxicities of New Drugs? S.D. Nelson. Session II. Biological Reactive Intermediates in Drug Discovery and Development A Perspective from the Pharmaceutical Industry; T.A. Baillie, K. Kassahun. Bioactiviation of Toxicants by Cytochrome P450-Mediated Dehydrogenation Mechanisms; G.S. Yost. New Aspects of DNA Adduct Formation by the Carcinogens Crotonaldehyde and Acetaldehyde; S.S. Hecht, et al. Mechanisms of Ovotoxicity Induced by Environmental Chemicals: 4-Vinylcyclohexene Diepoxide as a Model Chemical; P.B. Hoyer, et al. Mutagenicity and Carcinogenicity of Biological Reactive Intermediate's Derived A `Non-Genotoxic' Carcinogen; S.S. Lau, et al. Reactive Metabolites of 1,3-Butadiene: DNA and Hemoglobin Adduct Formation and Potential Roles in Carcinogenicity; A.A. Elfarra, et al. Chemistry and Biological Activity of Novel Selenium Containing Compounds; J.N.M. Commandeur, et al. Formation and Fate of Reactive Intermediates of Haloalkanes, Haloalkenes, and alpha-Haloacids; M.W. Anders. Short Communications. Session III. DNA Microarray Reveals Increased Expression of Thioredoxin Peroxidase in Thioredoxin-1 Transfected Cells and its Functional Consequences; B. Husbeck, et al. Reactive Nitrogen Species and Proteins: Biological Significance and Clinical Relevance; J.M. Souza, et al. Bicarbonate Enhances Nitration and Oxidation Reactionsin Biological Systems-Role of Reactive Oxygen and Nitrogen Species; B. Kalyanaraman, et al. Nitric Oxide and Peroxynitrite in Ozone-Induced Lung Injury; D.L. Laskin, et al. Antioxidant Reactions of Green Tea Catechins and Soy Isoflavones; D.C. Liebler, et al. Short Communications. Session IV. Chromosome Damage From Biological Reactive Intermediates of Benzene and 1,3-Butadiene in Leukemia; M.T. Smith. hOGG1 Gene Alterations in Human Clear Cell Carcinomas of the Kidney: Effect of Single Mutations in hOGG1 Gene on Substrate Specificity of the hOgg1 Protein; M. Audebert, et al. The Antitumor Agent Ecteinascidin 743: Characterization of its Covalent DNA Adducts and Chemical Stability; L.H. Hurley, M. Zewail-Foote. Design of DNA Damaging Agents that Hijack Transcription Factors and Block DNA Repair; J.M. Essigmann, et al. Short Communications. Session V. Are Blood-Brain Interfaces Efficient in Protecting the Brain From Reactive Molecules? J.-F. Ghersi-Egea, et al. The Roles of P-Glycoprotein and MRP1 in the Blood-Brain and Blood-Cerebrospinal Fluid Barriers; A.H. Schinkel. Are Dopamine, Norepinephrine, and Serotonin precursors of Biologically Reactive Intermediates Involved in the Pathogenesis of Neurodegenerative Brain Disorders? G. Dryhurst. Serotonergic Neurotoxicity of Methylenedioxyamphetamine and Methylenedioxymetamphetamine; T.J. Monks, et al. Session VI. Caspase Cascades in Chemically-Induced Apoptosis; S.B. Bratton, G.M. Cohen. Spermatogenesis by Sisyphus: Proliferating Stem Germ Cells Fail to Repopulate the Testis After `Irreversible' Injury; K. Boekelheide, H.A. Schoenfeld. The Interaction of 1,4-Benzoquinone, A Bioreactive Intermediate of Benzene, With Three Proteins Essential for Differentiation? Maturation of the Mo