Peroxisomes (microbodies) have a long evolutionary lifespan, but in cell biology they are still young. It is gratifying to see that most recent advances in our knowledge of peroxisomes come from quite different disciplines, ranging from molecular biology and cell biology to clinical research. The identification in terms of cDNA sequences of enzymes, the localization in terms of immuno-electron microscopy, and the cell biological aspects of the organelle biogenesis have seen substantial progress very recently. Likewise, the phenomenon of peroxisome proliferation induced by a number of drugs, e. g. hypolipidemics and plasticizers, constitute an active area of research, where much is still to be learnt. The medical problem of inborn errors of metabolism seems to have gained a new realm for discovery. Here, the advances in knowledge within the last year have been particularly striking. Therefore, the "International Symposium on Peroxisomes in Biology and Medicine", held in Heidelberg from July 14-17,1986, was even more excit ing than could have initially been anticipated. The present volume consists of papers from that conference. For sake of rapid publication, the camera ready format, inspite of all its drawbacks (e. g. no proof reading by authors), was chosen. It is our pleasure to acknowledge support and help. The Symposium was supported by Deutsche Forschungsgemeinschaft, Bonn, by the Ministerium ftir Wissenschaft und Kunst Baden-Wtirttemberg, Stuttgart, as well as by a number of generous contributors from industry.

Inhalt
One Peroxisomes and Lipid Biosynthesis.- Morphogenesis of Peroxisomes in Lipid-Synthesizing Epithelia.- Peroxisomes in Sebaceous Glands: Biosynthetic Role and Hormonal Regulation.- Peroxisomal Alkyl-Dihydroxyacetonephosphate Synthase and a Related Enzyme in Microsomes (Microsomal Synthase) of Rat Liver.- Localization of 3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase in Rat Liver Peroxisomes.- Dolichol Metabolism and Peroxisomes.- Liver Peroxisomes and Bile Acid Formation.- Peroxisomes, Proliferation, and the Synthesis of Phospholipids.- Evidence for a Link Between Peroxisomes and the Nonspecific Lipid Transfer Protein (Sterol Carrier Protein 2) in Rat and Human Liver.- Two Peroxisomes and Lipid Catabolism.- Comparison of Enzymes of Lipid ?-Oxidation in Peroxisomes and Mitochondria.- Cloning and Structural Analysis of the Genes for Peroxisomal ?-Oxidation Enzymes.- Immunoelectron Microscopy of Peroxisomal Enzymes; Their Substructural Association and Compartmentalization in Rat Kidney Peroxisomes.- ?-Oxidation Systems in Eukaryotic Microorganisms.- Higher Plant Peroxisomes and Fatty Acid Degradation.- Physiological Role of Peroxisomal Beta-Oxidation.- Three The Peroxisomal Membrane.- Permeability of the Peroxisomal Membrane.- Peroxisomal Properties with Potential Regulatory Implications: Selective ATP Requirement for Fatty Acid Oxidation and Membrane Protein Phosphorylation.- Glyoxysomal Membrane Electron Transport Proteins.- The Alkaline Lipase of the Glyoxysomal Membrane Is a Glycoprotein.- A Proton Translocating ATPase Is Associated with the Peroxisomal Membrane of Yeasts.- Study on Membrane Fluidity of Liver Peroxisomes.- Four Metabolic Pathways (Other than Lipids) in Peroxisomes.- Peroxisomal Glycolate Metabolism and the C2 Oxidative Photosynthetic Carbon Cycle.-Peroxisomal Oxidases and Their Probable Role in Controlling Animal Metabolism.- Amino Acid Metabolism in Animal Peroxisomes.- Aldehyde Dehydrogenase in Mammalian Peroxisomes.- Five Peroxisomes and Drugs.- Induction of Hepatic Peroxisome Proliferation by Xenobiotics.- Phenotypic Properties of Preneoplastic and Neoplastic Hepatic Lesions Induced by Peroxisome Proliferators in Rats.- The Relationship Between the Levels of Long-Chain Acyl-CoA and Clofibryl-CoA and the Induction of Peroxisomal ?-Oxidation.- Prevention of Peroxisomal Proliferation by Carnitine Palmitoyltransferase Inhibitors in Cultured Rat Hepatocytes and In Vivo.- Use of Primary Cultures of Adult Rat Hepatocytes to Study the Mode of Action of the Peroxisome Proliferator Nafenopin.- Effects of Antilipolytic Drugs on Hepatic Peroxisomes.- Induction of Cytochrome P450 and Peroxisome Proliferation in Rat Liver by Perfluorinated Octane Sulphonic Acid (PFOS).- Risks and Benefits of Agents Which Induce Hepatic Peroxisome Proliferation.- Automatic Image Analysis for Morphometric Studies of Peroxisomes.- Six Peroxisomes and Human Diseases.- Pathogenesis of Zellweger's Cerebro-Hepato-Renal Syndrome and Related Peroxisome Deficiency Diseases.- Observations About the Phenotype of Peroxisomal Disorders.- Biochemical Analysis in Peroxisomal Disorders.- Complementation Analysis of Peroxisomal Diseases by Somatic Cell Fusion.- Fatty Acid Metabolism in Cultured Skin Fibroblasts from Patients with Peroxisomal Disorders: Lignoceroyl-CoA Ligase Deficiency in Childhood Adrenoleukodystrophy.- Liver Peroxisomal Oxidizing Activities in Physiological and Pathological Conditions.- Deficiency of Peroxisomal Alanine: Glyoxylate Aminotransferase in Primary Hyperoxaluria Type 1.- Retrospective Immunocytochemical Demonstration ofPeroxisomal Enzymes in Human Liver Biopsies Processed Conventionally for Light and Electron Microscopy.- Seven Biogenesis of Peroxisomes.- to the Session on Biogenesis.- Biogenesis of Peroxisomes in Rat Liver and Candida Tropicalis.- Biogenesis of Rat Liver Peroxisomal Membrane Polypeptides.- Biogenesis of Plant Microbodies.- Biogenesis of Glycosomes (Microbodies) in the Trypanosomatidae.- Metabolic Significance and Biogenesis of Microbodies in Yeasts.