During the last two decades, the prevalence of obesity has dramatically increased in western and westernized societies. Its devastating health consequences include hypertension, cardiovascular diseases, or diabetes and make obesity the second leading cause of unnecessary deaths in the USA. As a consequence, obesity has a strong negative impact on the public health care systems. Recently emerging scienti?c insight has helped understanding obesity as a complex chronic disease with multiple causes. A multileveled gene-environment interaction appears to involve a substantial number of susceptibility genes, as well as associations with low physical activity levels and intake of high-calorie, low-cost, foods. Unfor- nately, therapeutic options to prevent or cure this disease are extremely limited, posing an extraordinary challenge for today's biomedical research community. Obesity results from imbalanced energy metabolism leading to lipid storage. Only detailed understanding of the multiple molecular underpinnings of energy metabolism can provide the basis for future therapeutic options. Numerous aspects of obesity are currently studied, including the essential role of neural and endocrine control circuits, adaptive responses of catabolic and anabolic pathways, metabolic fuel sensors, regulation of appetite and satiation, sensory information processing, transcriptional control of metabolic processes, and the endocrine role of adipose tissue. These studies are predominantly fuelled by basic research on mammalian models or clinical studies, but these ?ndings were paralleled by important insights, which have emerged from studying invertebrate models.

During the last two decades, the prevalence of obesity has dramatically increased in western and westernized societies. Its devastating health consequences include hypertension, cardiovascular diseases, or diabetes and make obesity the second leading cause of unnecessary deaths in the USA. As a consequence, obesity has a strong negative impact on the public health care systems. Recently emerging scienti?c insight has helped understanding obesity as a complex chronic disease with multiple causes. A multileveled gene-environment interaction appears to involve a substantial number of susceptibility genes, as well as associations with low physical activity levels and intake of high-calorie, low-cost, foods. Unfor- nately, therapeutic options to prevent or cure this disease are extremely limited, posing an extraordinary challenge for today's biomedical research community. Obesity results from imbalanced energy metabolism leading to lipid storage. Only detailed understanding of the multiple molecular underpinnings of energy metabolism can provide the basis for future therapeutic options. Numerous aspects of obesity are currently studied, including the essential role of neural and endocrine control circuits, adaptive responses of catabolic and anabolic pathways, metabolic fuel sensors, regulation of appetite and satiation, sensory information processing, transcriptional control of metabolic processes, and the endocrine role of adipose tissue. These studies are predominantly fuelled by basic research on mammalian models or clinical studies, but these ?ndings were paralleled by important insights, which have emerged from studying invertebrate models.

Cell surface receptors are multifunctional proteins with binding sites towards the external environment and effector sites which mediate intracellular events. The purpose of this symposium was to bring together investigators who have a com mon interest in those receptors which are located in the liver, and who have studied endocytic mechanisms for various macromolecules like insulin, lipoproteins, epi dermal growth factor and others. Experiments in this particular field of research date back to the early 60-ies but have only recently led to new and important in sight in the molecular basis of receptor mediated uptake in the liver. The structural features which control these mechanisms are currently under intense investigation in many laboratories. Though this symposium largely emphasizes lipoprotein up take and catabolism by the liver, it was the particular intention of the organizers to discuss methodology and results with investigators who are also interested in he patic uptake of macromolecules. This might then eventually lead to new and com mon concepts for both receptor-ligand interaction and internalization processes in the liver. Biochemists, pathologists and gastroenterologists met for two and a half days and discussed their latest data in this so rapidly developing field of basic rese arch. This conference is part of a series on current topics in gastroenterology and hepatology arranged regularly by the Departments of Medicine and Surgery at the University Hospital Eppendorf. If is our hope, that such exchange of information between the different disciplines in medicine will continue. i. k."