Publications by authors named "D Birkenhead"

The human cathelicidin peptide, LL-37, is a host defense peptide with a wide range of immunomodulatory activities and modest direct antimicrobial properties. LL-37 can exert both pro- and anti-inflammatory effects and can modulate the proinflammatory responses of human peripheral blood monocytes and epithelial cells. In this study, we evaluated the effect of LL-37 on mouse bone marrow-derived macrophages (BMDM) and tissue macrophages in vitro and in vivo.

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CD44 is expressed on T cells where its ability to bind hyaluronan is tightly regulated. Here, we investigated when T cells bind hyaluronan during an immune response. We found that naïve, murine T cells do not bind fluoresceinated hyaluronan but are induced to bind upon antigen-induced T-cell activation in vitro and in vivo.

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The tyrosine phosphatase CD45 dephosphorylates the negative regulatory tyrosine of the Src family kinase Lck and plays a positive role in TCR signaling. In this study we demonstrate a negative regulatory role for CD45 in CD44 signaling leading to actin rearrangement and cell spreading in activated thymocytes and T cells. In BW5147 T cells, CD44 ligation led to CD44 and Lck clustering, which generated a reduced tyrosine phosphorylation signal in CD45(+) T cells and a more sustained, robust tyrosine phosphorylation signal in CD45(-) T cells.

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Individuals who are asplenic or have impaired splenic function are at increased risk of developing life-threatening infections, especially due to encapsulated bacteria. This risk is higher in children, but adults can also develop fulminant infection or "post splenectomy sepsis" (PSS). Cryptococcus neoformans is an encapsulated yeast usually causing infection in immunocompromised patients.

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Mobile telephones were used to collect data on the relationship between gambling and mood state from gamblers in the field. Seventeen gamblers called an interactive voice response system running on a computer before, during and after a gambling episode. Measures taken in this way included self-reports of anxiety/arousal, the amount of money gambled, whether the result was a win or loss, the amount won or lost, and the type of gambling engaged in.

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