This volume represents a portion of the Proceedings of the Sixth International Meeting of the Reticuloendothelial Society. There is little question that the University of Freiburg was a most appropriate choice as the site of the meeting since, in essence, the Society was founded here when Aschoff undertook his classical studies on the macrophage and discovered what may well have been the last remaining biological system. In the approximate fifty years which have elapsed since Aschoff introduced the descriptive term Reticuloendothelial System to unify those cells with the common property of phagocytosis, one finds investigative activity at the highest level in all areas of reticuloendothelial involvement. Indeed, the topics covered in the present volume would of necessity require that the common property of phagocytosis which led to the formulation of the reticuloendothelial system be modified. The common basis at the present is clearly no longer phagocytic expression, but the unifying basis of host defense. The totality of reticuloendothelial involvement in host-defense is clearly reflected by the diverse scientific backgrounds and research interests of the participants of the meeting. Remarkable advances in appreciating the involvement of the RES in maintaining the well-being of the host against a variety of endogenous and exogenous factors have been made since volume I of the Advances in Experimental Biology and Medicine on the reticulo endothelial system was published.

Inhalt
Structure and Origin of Macrophages.- Electron Microscopic Cytochemistry of the Cell Coat of Kupffer Cells in Rat Liver.- Spreading of Macrophages on Glass and Its Relation to Recognition and the Cell Coat.- The Fine Structure and Peroxidase Activity of Resident and Exudate Peritoneal Macrophages in the Guinea Pig.- Kinetics, Cytochemistry and DNA-Synthesis of Blood Monocytes in Man.- Differentiation of Macrophage Antigen(s) in Mouse Bone Marrow and Buffy Coat Cultures.- Chemotaxis.- Chemotaxis of Phagocytes.- Chemotaxis of Phagocytic Cells Towards Proteins: The Effect of Protein Denaturation.- Leucocidin, DFP, the Leucocyte Potassium Pump and the Inhibition of Chemotaxis.- The Phagocytic Event.- Hypothesis: A Possible Relationship Between Blood Clotting and the Recognition by the Body of Foreign Particles.- The Stimulating or Depressing Effect of Various Drugs on the Phagocytic Function of the RES.- Quantitative Study of Sex Difference in RE Phagocytosis.- The Temporary Sequestration of C3-Coated Red Cells (EC43) in the RES of the Rabbit: A Mechanism for the Non-Lytic Damage of Red Cells by Complement.- Function and Importance of the RES During Perfusion of the Liver.- Function Studies of the Spleen Using Radioactive-Labeled and Heat-Denatured Erythrocytes and Their Clinical Value.- The Evaluation of Phagocytic Activity in Man by Means of a Lipid Clearance Test.- Macrophage Intracellular Metabolism.- Possible Participation of Serum-Complement in the Intracellular Killing of E. coli.- Fate of Streptococcal Antigens in the Reticulodendothelial Systems of the Mouse Liver.- Lysosomal Activity in Activated Macrophages of Rat Liver.- In Vitro Fixation and Degradation of Radioactive Endotoxin by the RES of BCG-Treated Mice.- Cytochemistry of Lysosomes of the Liver RES DuringMalaria Infection at the Electronmicroscopic Level.- Sequence of Events Leading to the Metabolic Stimulation in PMN Leucocytes During Phagocytosis.- The Biochemical and Antimicrobial Activities of the Phagocyte.- RES and Immunity.- Antimacrophage Serum: Its Effect on the Immunological Competence and Lymphoid Tissues of the Rat.- Macrophage Reversal of Anti-Lymphocyte Serum Induced Immunosuppression.- Differential Responses of Macrophage Precursors and Antibody Forming Cells to Immunization.- Light and Electron Microscopic Changes in Lymph Nodes After Local Application of Heterologous Antithymocyte and Antimacrophage Serum.- The Measurement of Cell-Mediated Immunity in Man.- In Vitro Studies of Delayed Hypersensitivity by the Method of Macrophage Spreading Inhibition. Delayed Hypersensitivity to Tuberculin and Diphtheria Toxoid in Rats.- Suppression of Second Set Reaction in Transplantation Immunity by Pretreatment with Histone of Graft Recipients and Donors.- The Depressive Effects of Immunoglobulin Containing Fractions of Serum upon Erythrophagocytosis.- RES in Host Defense.- Role of RES in the Defense Against Invasion by Neoplastic, Bacterial and Immunocompetent Cells.- Protective Effect of Reticuloendothelial System Stimulants in Combination with Chloroquine on Plasmodiumberghei Infection in Mice.- The Antileprosy Agent Clofazimine (B.663) in Macrophages: Light, Electron Microscope and Function Studies.- Reticuloendothelial Activity and Some Metabolic Changes Related to Trauma.- The Behaviour of Macrophages in Lung Cultures after Exposure to Cigarette Smoke. Evidence for Selective Inhibition by Particulate Matter and Stimulation by the Gas Phase of Cell Metabolism of Alveolar Macrophages.- RES and Neoplasia.- Tumor Growth in Relation to the Immunological Environment.- Macrophage Recognition Mechanisms: Clinical and Experimental Considerations.- Virus Induced Malignant Lymphome in Mice Dependent on a RES Conditioned by Chronic Parasitic Infection (P. berghei).- Pathomechanism of Increased RES Activity in Rats Bearing Yoshida Sarcoma.- Active Immunotherapy by B. C. G..- Author Index.