Proliferation of IL-2 activated lymphocytes preferably occurs in aggregates by cells expressing the CD57 antigen.

Aggregates of lymphocytes were investigated in long-term cultures of IL-2 stimulated peripheral blood mononuclear cells. Cells in clusters formed broad contact areas where coated pits and vesicles were often detectable. Proliferating cells were preferably found in aggregates indicating that the cell clusters represent proliferation centres in which cell division may be promoted by accessory signal transduction mediated by the close cell-to-cell contact.

[Major ambulatory surgery: organizational models].

In this essay, the authors provide a definition for those medical care facilities representing a consolidated alternative to traditional hospitalization. These facilities can be basically ascribed to the following patterns: day case surgery; day-hospital activity; home-care. Day case surgery is a complex and, in most cases, interdisciplinary procedure; this type of activity necessitates a pre-hospitalization period and often also a "protected discharge" or even a home-care service.