Search results for "Neutrophile"
showing 9 items of 9 documents
Polymorphonuclear leukocyte membrane fluidity and cytosolic Ca2+ concentration in diabetes mellitus.
1998
We evaluated polymorphonuclear membrane (PMN) fluidity in 32 subjects with type 1 diabetes mellitus, 38 subjects with type 2 diabetes mellitus and 38 normal control subjects, by marking intact and unstimulated PMN cells with the fluorescent probe 1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH). We also evaluated PMN cytosolic Ca2+ content by marking intact and unstimulated PMN cells with the fluorescent probe Fura 2-AM. PMN membrane fluidity differentiated normal subjects from type 1 and 2 diabetic subjects. The PMN cytosolic Ca2+ concentration did not discriminate type 1 and 2 diabetic subjects from normal control subjects. No statistical correlation was found between PMN …
15(S)-HETE modulates LTB(4) production and neutrophil chemotaxis in chronic bronchitis.
2000
We evaluated the levels of 15(S)-hydroxyeicosatetraenoic acid [15(S)-HETE] and the expression of 15-lipoxygenase (15-LO) mRNA in induced sputum obtained from 10 control and 15 chronic bronchitis subjects. 15(S)-HETE was evaluated by reverse phase high-performance liquid chromatography separation followed by specific RIA. 15-LO mRNA expression was determined by primed in situ labeling. The levels of both soluble and cell-associated 15(S)-HETE resulted significantly higher in chronic bronchitis than in control subjects. The percentage of cells expressing 15-LO mRNA was significantly higher in chronic bronchitis than in control subjects ( P < 0.01). Double staining for specific cell type ma…
Deep Venous Thrombosis: Leukocyte Rheology at Baseline and after in vitro Activation
2001
We evaluated leukocyte rheology, expressed as leukocyte filtration, polymorphonuclear (PMN) membrane fluidity and cytosolic Ca<sup>2+</sup> concentration in subjects with acute deep venous leg thrombosis (DVT). In 14 subjects with leg DVT we examined the leukocyte filtration [unfractionated, mononuclear cells (MN), PMNs], PMN membrane fluidity and PMN cytosolic Ca<sup>2+</sup> concentration. Subsequently, we evaluated the same PMN variables after in vitro chemotactic activation with 4-phorbol-12-myristate-13-acetate. At baseline, we observed a significant difference in the filtration of unfractionated and MNs and in PMN cytosolic Ca<sup>2+</sup> concentra…
Airway neutrophilia in COPD is not associated with increased neutrophil survival
2006
Neutrophilic airway inflammation is a prominent feature of chronic obstructive pulmonary disease (COPD) and correlates with disease severity. The mechanisms that determine the extent of neutrophilia could involve increased influx or prolonged survival of neutrophils. The aim of the study was to assess whether neutrophil pro-survival mechanisms are increased in the airways of subjects with COPD owing to the presence of anti-apoptotic factors in the bronchial lining fluid. Induced sputum samples were collected from 20 subjects with stable COPD, 14 healthy smokers and 14 healthy controls. Quantification of apoptotic neutrophils was based on typical morphological cell changes. Anti-apoptotic, p…
Staphylococcal alpha-toxin provokes neutrophil-dependent cardiac dysfunction: role of ICAM-1 and cys-leukotrienes.
2002
The role of polymorphonuclear neutrophils (PMN) in septic myocardial dysfunction is presently unknown. Staphylococcus aureus infections are frequently associated with septic sequelae. Therefore, we perfused isolated rat hearts with low doses of α-toxin, the major staphylococcal exotoxin, followed by application of human PMN, N-formyl-methionyl-leucyl-phenylalanine, and arachidonic acid. In contrast to sham-perfused hearts (no α-toxin), a rise in coronary perfusion pressure (CPP) and a reduction of contractile function were noted, and cardiac expression of intercellular adhesion molecule (ICAM)-1 was detected by immunohistochemical methods and real-time PCR. Histological analysis and myelope…
Olive Oil–Based Lipid Emulsion's Neutral Effects on Neutrophil Functions and Leukocyte–Endothelial Cell Interactions
2006
Infection remains a drawback of parenteral nutrition (PN), probably related, among other factors, to immunosuppressive effects of its lipid component. Newer preparations may have lesser immunosuppressive impact. This study examines the effects of an olive oil-based lipid emulsion (long-chain triacylglycerols-monounsaturated fatty acids [LCT-MUFA]; ClinOleic) on various functions of human neutrophils in vitro and on rat leukocyte-endothelial cell interactions in vivo compared with LCT (Intralipid) and 50% LCT-50% medium-chain triacylglycerols (MCT; Lipofundin) mixture.Neutrophils isolated from healthy donors were incubated with concentrations (0.03-3 mmol/L) of lipid emulsions encompassing c…
Acute Ischemic Stroke
2000
Background and Purpose —Several reports have considered the role of systemic leukocytes in acute ischemic stroke (AIS). Initially, greater attention was focused on the leukocyte count and subsequently on their adhesiveness, aggregation, rheology, and activation. The aim of this study was the evaluation of certain polymorphonuclear leukocyte (PMN) parameters, reflecting their rheology and activation, in subjects with AIS. Methods —In a group of 19 subjects with AIS and in a control group of 18 subjects with asymptomatic vascular atherosclerotic disease, we evaluated the PMN membrane fluidity and cytosolic Ca 2+ concentration at baseline and after in vitro chemotactic activation with 4-phorb…
Study of mechanisms of action of an immunotherapy by triacyl lipid A in humans
2013
Immunotherapy acting at the primary tumor site and preventing the development of metastases is one of the strategies for treatment of patients with cancer. To improve the efficiency of the latter, it is necessary to understand how it induces tumor cell death. In the laboratory, it was observed the cure of PROb tumors in rats BDIX by the triacyl lipid A. It has been shown that this effect involved the immune system involving interactions with TLRs present in many tumor cells and innate immunity cells such as neutrophils.In this work, we investigated the possible involvement of neutrophils in the antitumor activity of triacyl lipid A in humans.In a Phase 1 study in patients with refractory so…
Etude des mécanismes d'action d'une immunothérapie par un lipide A, seul ou associé à l'oxaliplatine, dans des modèles de cancers coliques
2013
Colorectal cancer is a major public health concern in France. Resistance to standard chemotherapy requires development of novel therapeutic approaches. In the past decades, our team showed the immunotherapeutic properties of lipid A in a model of colon cancer in rats. 95% of rats bearing small carcinomas were cured following treatment by lipid A. The study of mechanisms underlying this immunotherapy allowed us to show that the antitumor effect of lipid A was dependent on cytotoxicity induced by granzyme B produced by intratumoral neutrophils. Indeed, we have shown that, in the tumor microenvironment, neutrophils produced granzyme B and had a pro-tumorigenic N2 phenotype. When rats were trea…