(1) We investigated the trophic effect of pectin on the intestinal mucosa injured by formyl methionyl-leucyl-phenylalanine (FMLP), a chemoattractant produced by the intestinal bacterial flora. (2) We first demonstrated that oral administration of FMLP for 7 days reduced the disaccharidase activities and increased the permeability, measured by fluorescein-isothiocyanate-conjugated dextran, of ra...

Helicobacter pylori infection of the stomach is accompanied by a persistent polymorphonuclear leukocyte (PMNL) infiltrate of the mucosa. The aim of this work was to study the activation of human PMNL by substances produced by H pylori. Filtered H pylori conditioned media stimulated a significant PMNL oxidative burst (p less than 0.002). This was equal to 26% of the maximal response stimulated b...

Vav1 is a hemopoietic-specific Rho/Rac guanine nucleotide exchange factor that plays a prominent role in responses to multisubunit immune recognition receptors in lymphoid cells, but its contribution to regulation of neutrophil functions is unknown. Activated Rho family GTPases are critical participants in neutrophil signaling cascades initiated by binding of FMLP and other chemoattractants to ...

Anti-neutrophil cytoplasmic antibodies (ANCA) targeting proteinase 3 (PR3) possess a high sensitivity and specificity for Wegener's granulomatosis. Due to their capacity of directly activating neutrophils, a pathogenetic role for these autoantibodies has been proposed. We investigated the impact of subthreshold concentrations of monoclonal anti-PR3 antibodies (anti-PR3; 0.1 microg/mL) on neutro...

The formylpeptide receptors (nomenclature agreed by the NC-IUPHAR Subcommittee on receptor family [196]) respond to exogenous ligands such as bacterial product fMet-Leu-Phe (fMLP) and endogenous lipoxin A4 (LXA4), 15-epi-lipoxin A4, annexin I , cathepsin G, amyloid β42, serum A spinorphin, derived from β-haemoglobin. FPR1 also serves a plague for selective destruction of human immune cells Y. p...

We extend the FMLP to partitioned static-priority scheduling and derive corresponding worst-case blocking bounds. Further, we present the first implementation of the PCP, SRP, D-PCP, M-PCP, and FMLP synchronization protocols in a unified framework in a general-purpose OS and discuss design issues that were beyond the scope of prior algorithmic-oriented work on real-time synchronization.

The complement-derived anaphylatoxin C5a and a putative analogue of bacterial chemotactic factor (N-formyl-methionyl-leucyl-phenylalanyl [fMLP]), as well as bacterial lipid A, all stimulate human granulocyte (PMN) adhesiveness and superoxide (O-2) production in a concentration-dependent manner. Since attachment of particulate matter to the PMN membrane is an early event in the triggering of res...

Neutrophils from patients with myelodysplastic syndrome (MDS) show a disturbed differentiation pattern and are generally dysfunctional. To study these defects in more detail, we investigated reactive-oxygen species (ROS) production and F-actin polymerization in neutrophils from MDS patients and healthy controls and the involvement of N-formyl-L-methionyl-L-lucyl-L-phenylaline (fMLP) and granulo...

Activation of group IV cytosolic phospholipase A(2) (gIV-PLA(2)) is the essential first step in the synthesis of inflammatory eicosanoids and in integrin-mediated adhesion of leukocytes. Prior investigations have demonstrated that phosphorylation of gIV-PLA(2) results from activation of at least two isoforms of mitogen-activated protein kinase (MAPK). We investigated the potential role of phosp...