Search results for "Respiratory burst"
showing 10 items of 84 documents
Rapid generation of hydrogen peroxide contributes to the complex cell death induction by the angucycline antibiotic landomycin E
2017
Landomycin E (LE) is an angucycline antibiotic produced by Streptomyces globisporus. Previously, we have shown a broad anticancer activity of LE which is, in contrast to the structurally related and clinically used anthracycline doxorubicin (Dx), only mildly affected by multidrug resistance-mediated drug efflux. In the present study, cellular and molecular mechanisms underlying the anticancer activity of landomycin E towards Jurkat T-cell leukemia cells were dissected focusing on the involvement of radical oxygen species (ROS). LE-induced apoptosis distinctly differed in several aspects from the one induced by Dx. Rapid generation of both extracellular and cell-derived hydrogen peroxide alr…
Neutrophil Recruitment Is Regulated By Adamts-13 in a Murine Model of Invasive Aspergillosis
2015
Abstract Introduction: During inflammation von Willebrand factor (VWF) multimers are secreted as an acute phase protein whereupon the size and the prothrombotic activity play an essential role. The size of VWF multimers is regulated by the specific proteolytic activity of ADAMTS-13 (a disintegrin and metalloprotease with ThromboSpondin type 1 repeats-13) which is diminished under several pathological conditions. Employing a murine model of invasive pulmonary aspergillosis (IPA) we aimed to determine the relevance of this regulatory pathway for innate inflammatory responses and polymorphonuclear neutrophil (PMN) recruitment which is crucial for fungal clearance and survival. Methods: IPA was…
Effects of ethanol and acetaldehyde on phagocytic functions
1985
Although a number of skin diseases are characterized by the presence of an increased number of phagocytes in their lesions, the effects of alcohol on phagocytic functions are not clearly understood. Therefore, we measured the influence of ethanol and acetaldehyde on the generation of oxygen radicals, chemotaxis and the release of lysosomal enzymes from human phagocytes. We added 0.03%-3% ethanol and 0.005%-0.25% acetaldehyde to cell cultures. We found that both ethanol and acetaldehyde suppressed the generation of oxygen radicals from granulocytes and monocytes; the ID50 was achieved at concentrations of approximately 0.25% for ethanol and 0.03% for acetaldehyde. A significant inhibition of…
Hawthorn extract inhibits human isolated neutrophil functions.
2008
Hawthorn extract is a popular herbal medicine given as adjunctive treatment for chronic heart failure. In contrast to the cardiac properties of hawthorn extract, its anti-inflammatory effect has been scarcely investigated. This study examines the effects of a dry extract of leaves and flowers of Crataegus laevigata on various functional outputs of human neutrophils in vitro. Incubation of human neutrophils obtained from peripheral blood of healthy donors with C. laevigata extract (0.75-250 microg/ml) inhibited N-formyl-Met-Leu-Phe (FMLP)-induced superoxide anion generation, elastase release and chemotactic migration with potency values of 43.6, 21.9, and 31.6 microg/ml, respectively. By con…
Stimulatory TSH-Receptor Antibodies and Oxidative Stress in Graves Disease
2018
CONTEXT: We hypothesized that TSH-receptor (TSHR) stimulating antibodies (TSAbs) are involved in oxidative stress mechanisms in patients with Graves disease (GD). METHODS: Nicotinamide adenine dinucleotide phosphate oxidase, isoform 2 (NOX2); oxidative parameters; and oxidative burst were measured in serum, urine, and whole blood from patients with GD and control subjects. Superoxide production was investigated in human embryonic kidney (HEK)-293 cells stably overexpressing the TSHR. Lipid peroxidation was determined by immunodot-blot analysis for protein-bound 4-hydroxy-2-nonenal (4-HNE) in human primary thyrocytes and HEK-293–TSHR cells. RESULTS: Serum NOX2 levels were markedly higher in …
Increased respiratory burst activity of monocytes and polymorphonuclear leukocytes in psoriasis.
1982
SUMMARY We studied the respiratory burst activity of peripheral blood monocytes and polymorphonu clear leukocytes (PMN) in eleven patients with psoriasis and eleven healthy controls, using zymosan particles to activate the phagocytes in vitro. The activation of the phagocytes was measured in a luminol-enhanced chemiluminescence (CL) assay. We found a significantly higher respiratory burst activity of both monocytes and PMN in patients with psoriasis compared with the control subjects. The percentages of monocytes in psoriatics did not differ from those of the controls. The higher amount of zymosan-induced CL activity generated in the patient group was unrelated to the age of the individual.…
A macrophage-suppressing 40-kD protein in a case of pulmonary alveolar proteinosis.
1987
Pulmonary alveolar proteinosis (PAP) is a rare disease of unknown etiology. Macrophage dysfunctions are claimed to be involved in the pathogenesis. We investigated phagocytosis and oxidative metabolism of alveolar macrophages in a case of pulmonary alveolar proteinosis. These cells phagocytize normally and phagocytizable stimulants cause a normal oxidative burst. In response to the membrane signals phorbolmyristate acetate and aggregated immunoglobulin, however, no stimulated turnover of the oxidative metabolism can be observed. A 40-kD protein found in the lavage fluid mediates this macrophage-inhibiting effect. This phenomenon may contribute to the frequent opportunistic infections seen i…
Leukocytes in neuronal ceroid-lipofuscinoses: function and apoptosis
1997
The neuronal ceroid-lipofuscinoses (NCL) are a group of progressive encephalopathies with a fatal course that are mostly of autosomal recessive inheritance. The pathophysiological mechanisms causing the diseases are not known. The characteristic histomorphological feature of the NCL is an abnormal lysosomal accumulation of lipopigments in neural and extraneural cells, including peripheral blood leukocytes. We studied the function of peripheral venous blood immunocompetent cells in ten patients with NCL and in age- and sex-matched controls to determine how, if at all, the accumulation of intracytoplasmic storage material influences the functional capacity of affected tissue. Our results did …
Stimulus-Dependent Increased Generation of Oxygen Intermediates in Monocytes and Polymorphonuclear Leukocytes in Psoriasis
1985
Based on recent findings indicating increased respiratory burst activity of monocytes (M phi) and polymorphonuclear leukocytes (PMN) in psoriasis upon stimulation with zymosan particles, we examined the question of whether incubation with various stimuli always results in augmented oxidative metabolism in psoriatic phagocytes. We compared M phi and PMN isolated from the peripheral blood of 12 patients with psoriasis and 12 control individuals. We measured the generation of oxygen intermediates of resting and stimulated M phi and PMN by luminol-enhanced chemiluminescence. The stimulants applied were: (1) aggregated immunoglobulin (aggIg), (2) zymosan, (3) zymosan opsonized with autologous se…
4-dimethylamino-3′,4′-dimethoxychalcone downregulates iNOS expression and exerts anti-inflammatory effects
2001
Abstract Reactive oxygen and nitrogen species contribute to the pathophysiology of inflammatory conditions. We have studied the effects of a novel superoxide scavenger, 4-dimethylamino-3′,4′-dimethoxychalcone (CH11) in macrophages and in vivo. CH11 has been shown to inhibit the chemiluminescence induced by zymosan in mouse peritoneal macrophages and the cytotoxic effects of superoxide. In the same cells, the modulation by superoxide of nitric oxide (NO) production in response to zymosan was investigated. CH11 was more effective than the membrane-permeable scavenger Tiron for inhibition of inducible nitric oxide synthase (iNOS) protein expression and nitrite production. We have shown that CH…