BackgroundSepsis in elderly patients is a major cause of morbidity and mortality in the clinical setting. The aim of this study was to assess the diagnostic significance of volume conductivity scatter (VCS) parameters and to compare their reliability with that of inflammatory markers.MethodsPatients (N=85) were divided into 3 groups according to their clinical history and culture results: control (N=29), localized infection (N=38), and sepsis (N=18). VCS parameters were obtained using a UniCel DxH 800 Coulter system. Cut-off values were established based on receiver operator characteristic (ROC) curves.ResultsThe mean volumes of neutrophils (MNV) and monocytes (MMV) were higher in the sepsis group than in the localized infection and control groups (P=0.000 for both). The mean cell conductivity and low median angle light scatter of neutrophils were lower in the sepsis group than in the localized infection and control groups (P=0.029 and P=0.022, respectively). With a cut-off of 156.5, MNV had a sensitivity of 83.3% and a specificity of 78% in predicting sepsis.ConclusionMNV and MMV, which can be obtained easily using an automated blood analyzer, may be promising hematologic parameters for distinguishing elderly individuals with and without sepsis and may help clinicians in the diagnosis of sepsis.

BackgroundThe validation of sample stability through pneumatic tube system (PTS) is essential. The objective of this study was to evaluate the effects of PTS transportation on laboratory results.MethodsPaired EDTA and SST blood samples were collected from 56 randomly selected patients. Laboratory parameters were compared between PTS group and hand-delivered group.ResultsNo statistical differences were observed for complete blood counts, white blood cell differential parameters, erythrocyte sedimentation rate and most chemistry parameters between PTS and hand-delivered transport procedures. Mean platelet volume results obtained from samples transported through PTS were lower than that obtained from samples transported through hand-delivered method (P = 0.001). The results of aspartate aminotransferase (P = 0.000), lactate dehydrogenase (P = 0.000), and hemolysis index (P = 0.000) from PTS group were higher than that from hand-delivered group.ConclusionsAll laboratories should validate the stability of the results from samples according to transportation method.

Endotoxic responses to bacterial lipopolysaccharide (LPS) are triggered by Toll-like receptor 4 (TLR4) and involve the production of inflammatory mediators, including interleukin-6 (IL-6), by macrophages. The detailed mechanism of IL-6 production by macrophages in response to LPS has remained unclear, however. We now show that LPS induces IL-6 synthesis in mouse peritoneal macrophages via the leukotriene B 4 receptor BLT2. Our results suggest that TLR4-MyD88 signaling functions upstream of BLT2 and that the generation of reactive oxygen species (ROS) by NADPH oxidase 1 (Nox1) and consequent activation of the transcription factor nuclear factor (NF)-κB function downstream of BLT2 in this response. These results suggest that a TLR4-MyD88-BLT2-Nox1-ROS-NF-κB pathway contributes to the synthesis of IL-6 in LPS-stimulated mouse macrophages.

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Mast cells are among the principal effector cells in the pathogenesis of allergic asthma. In allergic reactions, allergen (Ag)-induced cross-linking of IgE bound to FcεRI on mast cells results in the production of vascular endothelial growth factor (VEGF), which is essential for the initiation and development of the allergic response. Despite the central role of VEGF in allergic asthma, the signaling events responsible for the production of VEGF remain unclear, particularly in Ag-stimulated mast cells. In the present study, we observed that blocking leukotriene B4 receptor 2 (BLT2) completely abrogated the production of VEGF in Ag-stimulated bone marrow-derived mast cells (BMMCs). The synthesis of BLT2 ligands (leukotriene B4 and 12(S)-hydroxyeicosatetraenoic acid) was also required for VEGF production, suggesting a mediating role of an autocrine BLT2 ligands-BLT2 axis in the production of VEGF in mast cells. The NADPH oxidase 1-reactive oxygen species-NF-κB cascade is downstream of BLT2 during Ag signaling to VEGF synthesis in mast cells. Furthermore, the level of VEGF synthesis in genetically mast cell-deficient Kit(W/Wv) mice was significantly lower than that in wild-type mice in the OVA-induced asthma model, suggesting that mast cells play a critical role in the synthesis of VEGF in OVA-induced allergic asthma. Importantly, VEGF production was restored to the levels observed in wild-type mice after adoptive transfer of normal BMMCs into Kit(W/Wv) mice but was not restored in BLT2(-/-) BMMC-reconstituted Kit(W/Wv) mice in the OVA-induced asthma model. Taken together, our results suggest that BLT2 expression in mast cells is essential for the production of VEGF in OVA-induced allergic asthma.