Blockade of LTB(4) /BLT(1) pathway improves CD8(+) T-cell-mediated colitis.

Background: Leukotriene B4 (LTB(4) ) has chemotactic properties for activated T cells expressing the high-affinity receptor BLT(1) . This study investigated whether the LTB(4) antagonist (CP-105,693), selective for BLT(1) receptor, could protect mice from colitis mediated by specific cytotoxic CD8(+) T lymphocytes (CTL).

Methods: Virus-specific colitis was induced in C57Bl/6 mice transferred with lymphoid cells from P14 TcR Tg mice which are specific to class I GP33 peptide of LCMV.

Mast cell-dependent down-regulation of antigen-specific immune responses by mosquito bites.

While probing host skin to search for blood vessels, the female Anopheles mosquito delivers Plasmodium parasites in the presence of saliva. Saliva from various blood-feeding vectors which contains several pharmacologically active components is believed to facilitate blood feeding as well as parasite transmission to the host. Recently, we found that mosquito saliva has the capacity to activate dermal mast cells and to induce local inflammatory cell influx.

Anopheles mosquito bites activate cutaneous mast cells leading to a local inflammatory response and lymph node hyperplasia.

When Anopheles mosquitoes probe the skin for blood feeding, they inject saliva in dermal tissue. Mosquito saliva is known to exert various biological activities, but its perception by the immune system and its role in parasite transmission remain poorly understood. In the present study, we report on the cellular changes occurring in the mouse skin and draining lymph nodes after a Anopheles stephensi mosquito bite.

[Hypernatremia in the aged: clinical characteristics].

Objective: Hypernatremia in young adults is a rare condition, sometimes occurring after gastrointestinal diseases, osmotic diuresis or diabetes insipidus. The clinical characteristics and prognosis of hypernatremia in geriatric patients would be different. Each case must be examined separately.