This Pediatric Nephrology series is a focus on salient points which at the time of each annual seminar are of importance to the practicing pediatrician and nephrologist, the clinical researcher, and basic researcher interested in clinical problems. Hence the format of selected papers and panel discussions to capture the tenor of the times. More thorough coverage of many of the subjects can be found in current journals and textbooks listed in the authors' references. Those searching for the conventional should look there rather than here since our aim is not to cover each subject in its entirety but to secure attention to the controversial aspects of the subjects, dispel the notion that there is one answer to a question, and raise the level of inclination toward dynamic problem solving. The basic subject chosen this year reflects dominant concerns this year and the participants chosen--speakers and discussants--represent certain views relevant to the subject at this time. To reflect the tempo and flavor produced by this unique blend, the discussions are included almost verbatim. For some this means readability; for others, excess verbiage. The careful reader will notice that I have been the chairman of all sessions and have moderated all discussions. This is in keeping with our aim to ferret out interrelated basic questions and varying answers to the subjects--seen as related in problems and solutions. In the discussions, all names have been deleted.