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Effective immune surveillance is essential for maintaining protection and homeostasis of peripheral tissues. However, mechanisms controlling memory T cell migration to peripheral tissues such as the skin are poorly understood. Here, we show that the majority of human T cells in healthy skin express the chemokine receptor CCR8 and respond to its selective ligand I-309/CCL1. These CCR8+ T cells are absent in small intestine and colon tissue, and are extremely rare in peripheral blood, suggesting healthy skin as their physiological target site. Cutaneous CCR8+ T cells are preactivated and secrete proinflammatory cytokines such as tumor necrosis factor–α and interferon-γ, but lack markers of cytolytic T cells. Secretion of interleukin (IL)-4, IL-10, and transforming growth factor–β was low to undetectable, arguing against a strict association of CCR8 expression with either T helper cell 2 or regulatory T cell subsets. Potential precursors of skin surveillance T cells in peripheral blood may correspond to the minor subset of CCR8+CD25− T cells. Importantly, CCL1 is constitutively expressed at strategic cutaneous locations, including dermal microvessels and epidermal antigen-presenting cells. For the first time, these findings define a chemokine system for homeostatic T cell traffic in normal human skin.

Durotomy does not increase SCBF in dogs with disk extrusion associated spinal cord compression.

Retroperitoneoscopy has gained popularity because it offers a safe alternative to the more debilitating open approach and avoids postoperative ileus. However, this type of procedure carries certain disadvantages in terms of intraperitoneal effusions and hemodynamic changes. Major complications are exceptional. We describe the case of a 52-year-old man who died of carbon dioxide embolism during elective totally extraperitoneal (TEP) inguinal hernioplasty for symptomatic left indirect inguinal hernia. With the patient under general anesthesia, the retroperitoneal space was gained through a 1. 5-cm incision made below the umbilicus. During the dissection, the patient collapsed and could not be resuscitated. At autopsy, air bubbles were admixed with blood in the epicardial veins, but no injury to vessels was demonstrated. We conclude that carbon dioxide embolism usually is caused by direct puncture of major vessels during intra-abdominal procedures. However, when this complication occurs during retroperitoneoscopy, it seems related to pressure-forced entry of carbon dioxide into the venous plexus.

No abstract