Several groups have recent ly repor ted the existence of a popu la t i on of h u m a n T cells capab le of p ro l i fe ra t ing in response to signals from autologous, non-T, mononuclear cells (1-4). As the s t imula to r cells have not been purpose ly modif ied, this pro l i fe ra t ion m a y represent recogni t ion of una l t e red self de te rminants . In this report , we have inves t iga te...

Recent neuroimaging studies suggest that the brain adapts with pain, as well as imparts risk for developing chronic pain. Within this context, we revisit the concepts for nociception, acute and chronic pain, and negative moods relative to behavior selection. We redefine nociception as the mechanism protecting the organism from injury, while acute pain as failure of avoidant behavior, and a meso...

It is well accepted that cytotoxic lymphocytes specific for viruses (1), haptens (2), and minor histocompatibility antigens (HA) 1 (3, 4) recognize antigen in an H-2restricted fashion during the effector phase. Precisely how the precursors of these cells respond to antigen during the induction phase, however, is poorly understood. In the case of skin graft rejection (5-9) and delayed-type hyper...