Physiologic responses to high and low leptin concentrations are strikingly asymmetrical. High concentrations often produce minimal effects, whereas low concentrations provoke strong counterregulatory responses. A model and rationale for the physiology is presented.

concerns over limited medical equipment and resources, particularly in intensive care units (icus), have raised the issue of medical futility. medical futility draws a contrast between physician’s authority and patients’ autonomy and it is one of the major issues of end-of-life ethical decision-making. the aim of this study was to review medical futility and its challenges. in this systematized...