Search results for "N-Formylmethionine Leucyl-Phenylalanine"
showing 9 items of 19 documents
Polymorphonuclear leukocyte integrins in deep venous thrombosis
2005
The polymorphonuclear leukocytes (PMN) have a role in the pathophysiology of deep venous thrombosis (DVT). We examined the phenotypical expression of PMN beta2-integrins (CD l l a, CDl l b, CD 11c) in a group of 19 subjects with leg DVT. PMN cells were incubated with fluorescent monoclonal antibodies against CD11a, CD11b, CD11c, and the evaluation was made by flow cytofluorimetry. The same integrins were determined after in vitro activation with 4-phorbol 12-myristate 13-acetate (PMA) and N-formylmethionyl-leucyl-phenylalanine (fMLP). In DVT subjects, at baseline, the phenotypical expression of CD11b was decreased and that of CD11c increased when compared with normal controls. In normal su…
Polymorphonuclear leukocyte integrins in chronic renal failure
2005
Patients with chronic renal failure (CRF), in comparison with general population, show a higher cardiovascular mortality, not fully explained by the "traditional" risk factors. Among the new factors that have been hypothesized, leukocytes might play an important role. In a group of patients with mild CRF we determined, at baseline and after in vitro activation with 4-phorbol-12-myristate-13-acetate (PMA) and N-formyl-methionyl-leucyl-phenylalanine (fMLP), the polymorphonuclear leukocytes (PMN) beta2-integrin pattern (CD11a, CD11b, CD11c and CD18) by using indirect immunofluorescence with a flow cytometer. At baseline we observed an increase in the phenotypical expression of CD11b, CD11c and…
Pharmacological activity of PF-904 in guinea pig in vivo, and on human bronchus and neutrophils in vitro.
1997
The effects of PF-904 (4-amino-1-ethyl-6-methylpyrazino[2,3-c][1,2,6]thiadiazine 2,2-dioxide), a pyrazinothiadiazine derivative, were examined in guinea-pig airways in vivo, in human isolated bronchus and human polymorphonuclear leukocytes. PF-904 (12.5-200 mg/kg, intraduodenal) reduced bronchoconstriction in response to histamine, arachidonic acid, platelet-activating factor (PAF) and methacholine. PF-904 (50-200 mg/kg) prevented PAF-induced airways hyperreactivity and inhibited antigen-induced bronchoconstriction, airway microvascular leakage and eosinophil lung accumulation, but antigen-induced airways hyperresponsiveness was not reduced. PF-904 (1 microM-1 mM) produced complete inhibiti…
Influence of anti-inflammatory flavonoids on degranulation and arachidonic acid release in rat neutrophils.
1994
We assessed the effects of 24 flavonoid derivatives, reported as anti-inflammatory, on lysosomal enzyme secretion and arachidonic acid release in rat neutrophils. Amentoflavone, quercetagetin- 7-O -glucoside, apigenin, fisetin, kaem pferol, luteolin and quercetin were the most potent inhibitors of β-glucuronidase and lysozyme release. The first com pound was also able to inhibit basal release. These flavonoids besides chrysin and to a reduced extent, naringenin, significantly inhibited arachidonic acid release from membranes. A correlation between degranulation and arachidonic acid release was found for this series of compounds. Structureactivity relationships and implications for the anti-…
Effect of two phenanthrene alkaloids on angiotensin II-induced leukocyte-endothelial cell interactionsin vivo
2003
The present study has evaluated the effect of two phenanthrene alkaloids, uvariopsine and stephenanthrine, on angiotensin II (Ang-II)-induced leukocyte–endothelial cell interactions in vivo and the mechanisms involved in their activity. Intravital microscopy within the rat mesenteric microcirculation was used. A 60 min superfusion with 1 nM Ang-II induced a significant increase in the leukocyte–endothelial cell interactions that were completely inhibited by 1 μM uvariopsine cosuperfusion. A lower dose of 0.1 μM significantly reduced Ang-II-induced leukocyte adhesion by 75%. When Ang-II was cosuperfused with 1 and 0.1 μM stephenanthrine, Ang-II-induced leukocyte responses were significantly …
Neutrophil activation in severe, early-onset COPD patients versus healthy non-smoker subjects in vitro: effects of antioxidant therapy.
2011
<i>Background:</i> Neutrophils and oxidative stress have been implicated in the pathogenesis of COPD. Severe, early-onset COPD is characterized by a rapid decline in the lung function at an early age; however, nothing is known about neutrophil activation in COPD patients. <i>Objectives:</i> The aim of this study was to evaluate peripheral blood neutrophil activation in severe, early-onset COPD patients versus healthy non-smokers and the effect of N-acetyl-<i>L</i>-cysteine (NAC) on neutrophil activation in vitro. <i>Methods:</i> Neutrophils were isolated from 15 severe, early-onset COPD patients and 15 age-matched healthy subjects and stimulat…
Heparin-binding protein targeted to mitochondrial compartments protects endothelial cells from apoptosis.
1999
Neutrophil-borne heparin-binding protein (HBP) is a multifunctional protein involved in the progression of inflammation. HBP is stored in neutrophil granules and released upon stimulation of the cells in proximity to endothelial cells. HBP affects endothelial cells in multiple ways; however, the molecular and cellular mechanisms underlying the interaction of HBP with these cells are unknown. Affinity isolation and enzymatic degradation demonstrated that HBP released from human neutrophils binds to endothelial cell-surface proteoglycans, such as syndecans and glypican. Flow cytometry indicated that a significant fraction of proteoglycan-bound HBP is taken up by the endothelial cells, and we …
Type II diabetics with macrovascular complications: polymorphonuclear leukocyte (PMN) filtration, PMN membrane fluidity and cytosolic Ca2+ content af…
1998
We evaluated polymorphonuclear (PMN) filtration parameters, membrane fluidity and cytosolic Ca2+ content in 21 normal subjects and in 18 type II diabetics with macrovascular complications (MVC). Evaluations were carried out at baseline and after in vitro activation prolonged for 5 and 15 min. PMA (4-phorbol 12-myristate 13-acetate) and fMLP (N-formyl-methionyl-leucyl-phenylalanine) were used as stimulating agents. TMA-DPH (1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene) was used as fluorescent probe for the membrane fluidity tests and Fura 2-AM for the cytosolic Ca2+ content. A significant variation was evident in PMN filtration parameters at 5 and 15 min. No variation was present i…
Bafetinib inhibits functional responses of human eosinophils in vitro
2012
Eosinophils play a prominent role in the process of allergic inflammation. Non-receptor associated Lyn tyrosine kinases generate key initial signals in eosinophils. Bafetinib, a specific Abl/Lyn tyrosine kinase inhibitor has shown a potent antiproliferative activity in leukemic cells, but its effects on eosinophils have not been reported. Therefore, we studied the effects of bafetinib on functional and mechanistic responses of isolated human eosinophils. Bafetinib was more potent than non-specific tyrosin kinase comparators genistein and tyrphostin inhibiting superoxide anion triggered by N-formyl-Met-Leu-Phe (fMLF; 100 nM) (−log IC50=7.25±0.04 M; 6.1±0.04 M; and 6.55±0.03 M, respectively).…