The transition from naïve to primed nociceptive state: A novel wind-up protocol in mice.

Wind-up (WU) is a progressive, frequency-dependent facilitation of spinal cord neurons in response to repetitive nociceptive stimulation of constant intensity. We identified a new WU-associated phenomenon in naïve mice (not exposed to noxious stimulation immediately prior to WU stimulation), which were subjected to a novel experimental protocol composed of three consecutive trains of WU stimulation. The 1st train produced a typical linear 'wind-up' curve as expected following a repeating series of stimuli; in addition, this 1st train sensitized ('primed') the nociceptive system so that the responses to two subsequent trains (inter-train interval of 10 min) were significantly amplified compared with the response to the 1st train.

Involvement of adenosine in the antiinflammatory action of ketamine.

Background: Ketamine is an anesthetic drug. Subanesthetic doses of ketamine have been shown to reduce interleukin-6 concentrations after surgery and to reduce mortality and the production of tumor necrosis factor alpha and interleukin 6 in septic animals. Similarly, adenosine was shown to reduce tumor necrosis factor alpha and mortality of septic animals.

CD40 ligand (CD154) takes part in regulation of the transition to mononuclear cell dominance during peritonitis.

Background: CD40 is a member of the tumor necrosis factor (TNF) family of receptors whose ligand (CD154) is found mainly on membranes of activated mononuclear cells. CD154-CD40 cross-linking is a central event in antigen presentation, B-cell activation, and regulation of cytokine and chemokine secretion from various types of cells. We have previously demonstrated in vitro the presence of CD40 on human peritoneal mesothelial cells (PMC) and have also shown that CD40 ligation synergizes with interferon-gamma (IFN-gamma) to up-regulate CC chemokine secretion from these cells.