The Journal of laboratory and clinical medicine
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The effect of hemodilution on the intestinal microcirculatory oxygenation is not clear. The aim of this study was to determine the effect of moderate normovolemic hemodilution on intestinal microvascular partial oxygen pressure (Po2) and its relation to the mesenteric venous Po2 (Pmvo2). Normovolemic hemodilution was performed in 13 anesthetized male Wistar rats. ⋯ Intestinal microvascular Po2 and oxygen consumption were well preserved during moderate normovolemic hemodilution. These results might be explained by the notion of others that hemodilution induces recruitment of capillaries, resulting in redistribution of the intestinal blood flow in favor of the microcirculation, which allows a more efficient extraction of oxygen. These findings further indicate that the use of venous Po2 values as indicators of microvascular oxygenation may be misleading.
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Anti-inflammatory substances are released during septic shock that modulate monocyte function. Decreased monocyte responsiveness to bacterial toxins and decreased expression of human-leukocyte-associated antigen-DR (HLA-DR) have been reported during septic shock and critical illness. Impaired antigen presentation has been inferred from these observations but has not been demonstrated. ⋯ These data indicate that antigen presentation is decreased in critically ill patients with sepsis. This appears in part related to decreased expression of HLA-DR and the costimulatory molecules CD86 and CD28. Increased expression of the negative signal receptor CTLA-4 may also impair antigen presentation in patients with sepsis.
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Recent studies emphasize the role of blood constituents in Staphylococcus aureus (S. aureus) adherence to subendothelial extracellular matrix. In the present study, the adherence of two strains of S. aureus (ATCC 29213 and RN 6390) grown to a postexponential phase to cultured human umbilical vein endothelial cells (EC-304) was examined. Under flow conditions (600 s(-1)), pretreatment of endothelial cells (ECs) with human alpha-thrombin (2 U/mL) significantly (2- to 4-fold) increased bacterial adherence to ECs. ⋯ Preincubation of S. aureus with a fibrinogen gamma-chain binding domain peptide led to 65% inhibition of adherence to ECs in the presence of fibrinogen. In contrast, preincubation of bacteria with the Arg-Gly-Asp-Ser peptide failed to affect their adherence. The data suggest that S. aureus adherence to the EC surface was (1) significantly enhanced by thrombin treatment of ECs, (2) not mediated by platelets, and (3) mediated by plasma fibrinogen, which binds to the bacteria via the C-terminus gamma-chain binding domain but not via the Arg-Gly-Asp sequence.
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Comparative Study
Evaluation of interleukin-6 in bronchoalveolar lavage fluid and serum of patients with lung cancer.
Increased levels of serum interleukin 6 (IL-6) are found in patients with lung cancer, and it has been shown that this is part of a systemic inflammatory response syndrome. This study was designed to measure IL-6 levels in bronchoalveolar lavage (BAL) fluid of patients with lung cancer and to describe the relationship of BAL fluid IL-6 to the known systemic increase in IL-6. Increased levels of BAL fluid IL-6 can be found in patients with lung cancer as compared with patients with chronic obstructive pulmonary disease who have acute infection (P = .007). ⋯ Serum IL-6 correlated with other acute phase reactants. This study thus demonstrates the feasibility of utilizing BAL fluid analysis for local cytokine/tumor marker production in lung carcinoma. It also shows that a local increase in IL-6 in the BAL fluid is independent of the systemic inflammatory response syndrome, whereas the serum increase in IL-6 is part of this syndrome.