J Benveniste's research while affiliated with Université Paris-Sud 11 and other places

Publications (321)

Article
The release of mediators from human basophils is strongly enhanced by lL-3. However, the signalling pathways of IL-3 arc poorly defined in these cells. Since external Ca2+ and Na+ play important regulating roles in histamine release, the possibility that these cations could be involved in the potentiation by rL-3 of the anti-IgE-induced histamine r...
Article
We report the transfer of the activity of 4-phorbol-12-beta-myristate-13-acetate (PMA) by electronic means. Neutrophils were placed at 37 degrees C on one coil attached to an oscillator, while PMA was placed on another coil at room temperature. The oscillator was then turned on for 15 min, after which cells were usually further incubated for up to...
Article
After HPLC purification of human blood extracts, paf-acether (paf) was found exclusively as a lipoprotein-bound compound (lipopaf), whereas free-paf was absent. When the same samples (or lipopaf recovered from HPLC) were purified by TLC, both free-paf and lipopaf were detected. The free-paf detected in blood samples could thus result from lipopaf d...
Article
The tissue concentrations of several inflammatory mediators were determined from day 0 to day 60 in granuloma induced in rats (n = 105) by injection of carrageenan in the fascia of the latissimus dorsi muscle. Noncollagen proteins (NCP) and the number of polymorphonuclear leukocytes (PMN) and mast cells were also assessed. In comparison with the ti...
Article
The ciliary beat frequency (CBF) of the tracheal epithelial cells controls in part the respiratory tract mucociliary transport efficiency. We investigated the effects on CBF of PAF-acether (PAF) and its metabolite/precursor lyso-PAF. Guinea-pig tracheal rings were incubated for 3 to 6 h with 1 μM PAF (C16, C18, C16/C18: 80/20%), lyso-PAF C16 or lys...
Article
The origin of the thrombocytopenia and leucopenia induced by protamine-heparin complexes is unknown. We studied the biochemical and cellular effects of protamine (6 mg x kg-1, i.v.) injected after heparin (5 mg x kg-1, i.v.) in New Zealand rabbits. After protamine injection (0.5 min) increases in blood platelet-activating factor (PAF-acether, PAF)...
Article
The authors have previously reported that platelet-activating factor (PAF), a phospholipid mediator with potent proinflammatory activities, is produced in the gastric mucosa and stimulates gastric acid secretion in humans and animals. In the present study they used the human gastric tumour cells HGT1 (clone 6) to examine whether PAF production is r...
Article
Liver and plasma concentrations in paf-acether (paf) and related phosphocholines, i.e., lysopaf and the ether lipid 1-O-alkyl-2-acyl-sn-glycero-3-phosphocholine (AAGPC) were studied in rats following two-third hepatectomy. We report a rapid increase in hepatic content of the 3 phospholipids at early steps of the regeneration process, when hepatocyt...
Article
PAF-acether (PAF) is a phospholipid synthesized by numerous inflammatory cells. PAF can produce several pathological changes in various organs, especially in the colon. In animals PAF causes colonic ulceration and inflammation, which are similar to the anatomic lesions seen in human ulcerative colitis. The aim of this study was to measure in vivo c...
Article
Previous studies suggest that the biological activity of agonists can be transferred to water by electromagnetic means [1-7]. Since July 1995, in keeping with these results, we have digitized, recorded, and 'replayed' to water the activity of acetylcholine (ACh) or water (W) as control. ACh and W were recorded (16 bits, 22 KHz), for 1-5 sec, via an...
Article
The molecular signal of PMA can be electronically transmitted and modulate neutrophil reactive oxygen metabolite (ROM) production as if PMA itself was added to the cells [1]. Experiments reported here were done blind or open at INSERM U 332, ICGM, Paris.Transmission was performed via an especially designed amplifier connected to two coils [2]. The...
Article
Electrokinetic behaviour of human lymphocytes was studied by photon correlation spectroscopy technique on laser IR-spectrometer. The electrophoretic mobilities (EPMs) were measured for peripheral blood lymphocytes (PBL) and CEM-C12 T cell line in 1:1 electrolyte at 22 degrees C. Plots of mobility vs ionic strength in the range 0.001-0.1 M were comp...
Article
An interaction of the platelet-activating factor (Paf) with endothelial cells was investigated using human umbilical vein endothelial cells. Confluent endothelial cells bound [3H]Paf in the presence of 0.25% fatty acid-free serum albumin after culture in media containing either heat-inactivated foetal calf serum or serum substitute. The Scatchard a...
Article
Full-text available
The presence of voltage-dependent ion channels (particularly Ca2+ channels) on the surface of 'non excitable' cells such as human basophils is a matter of debate. Indeed, in basophils, Ca2+ entry or mobilization is not sufficient by itself to trigger secretion, although enhanced cytosolic Ca2+ concentration increases it. In order to address this qu...
Article
To evaluate the role of platelet activating factor (PAF) in the early stage of arthritis. Arthritis was induced in rabbits by weekly intra-articular injections of carrageenan. A PAF receptor antagonist, BN 50730, was used as a preventive or curative agent. BN 50730 was able partially to prevent the development of arthritis, and was also active on e...
Article
The aim of this study was to evaluate the presence of PAF-acether (PAF), its specific degrading enzyme acetylhydrolase, and tumor necrosis factor (TNF) concentrations in blood and synovial fluid (SF) from patients with active RA. The variations of the mediators were also evaluated after corticosteroid perfusions in 7 patients. Lipo-PAF (PAF complex...
Article
Nature is the international weekly journal of science: a magazine style journal that publishes full-length research papers in all disciplines of science, as well as News and Views, reviews, news, features, commentaries, web focuses and more, covering all branches of science and how science impacts upon all aspects of society and life.
Article
We previously showed in a human T cell line (CEM-C12 cells) that Cd2+ induced gene expression of stress proteins, metallothionein-IIA and heat shock protein 70 in a time- and dose-dependent manner. In the present study, CEM-C12 cells were pretreated for 24 h with 1 μM Cd2+ and then challenged with toxic concentrations of this metal. We found that m...
Article
Cadmium, a potent toxic metal, poses a serious environmental threat but the mechanisms of its toxicity remain unclear. In the present study, we investigated the nature of cadmium-induced cell death in the human T cell line CEM-C12. Cadmium was time- and dose-dependently toxic for CEM-C12 cells, cell death being preceded by chromatin condensation an...
Article
Full-text available
The release of mediators from human basophils is strongly enhanced by IL-3. However, the signalling pathways of IL-3 are poorly defined in these cells. Since external Ca2+ and Na+ play important regulating roles in histamine release, the possibility that these cations could be involved in the potentiation by IL-3 of the anti-IgE-induced histamine r...
Article
Full-text available
Basophils play a major role in allergic reactions-particularly in late phase reactions-by releasing histamine and other mediators of inflammation. Although transmembrane ion fluxes are thought to play an important role in the modulation of histamine release, little is known about ion pathways through the basophil membrane. We thus studied human bas...
Article
Isolated guinea pig hearts were perfused, by the Langendorff technique, with 30, 15, 7.5, and 1.5 μM Zn2+ in Chenoweth solution. Contractile force, coronary flow, and heart rate were recorded by means of Narco IV Physiograph. Calcium inhibitor (Verapamil 1 μM) and anion inhibitor (DIDS: 0.1, 1, and 5 μM) were used subsequently in the perfusing solu...
Article
Full-text available
The release of platelet activating factor (PAF-ACETHER or PAF) and its precursors in the gastric lumen was assessed in 13 normal subjects in basal condition and after stimulation by gastrin. Acid, pepsin, and sialic acid outputs were determined under the same conditions. Gastric juice was collected using a nasogastric tube after overnight fast in b...
Article
Intact washed human platelets aggregated in response to paf-acether (paf) and did not metabolize [3H]paf at concentrations up to 10 nM. However, when platelets were lysed by exposure to pH 9.5, resulting in 37.5 +/- 2.5% (mean +/- SD, n = 3) lactic dehydrogenase (LDH) release, 20.5 +/- 5.7% of the radioactivity was detected as labeled lyso paf and...
Article
We investigated the ability of a phospholipid cytokine, paf-acether to modulate programmed cell death in an immature human T cell line CEM-C12. Paf-acether alone did not cause cell death, but when it was added to CEM-C12 cells in the presence of calcium ionophore, a marked increase in cell mortality and DNA fragmentation was observed compared with...
Article
Full-text available
The autoimmune aetiology of type I diabetes has been well documented. We studied whether anti-insulin anaphylactic antibodies were present on the membrane of basophils from type I diabetics by the toluidine blue method (detecting basophil activation after stimulation by insulin). We observed that basophils of recently diagnosed insulin-dependent di...
Article
Extracorporeal circulation (ECC) is associated with thrombocytopenia and transient leukopenia. After ECC and coronary artery bypass graft (CABG) surgery, some patients can develop pulmonary and cardiac dysfunction, which might be related to the release of various mediators such as thromboxane A2, C5a, and C3a anaphylatoxins. The involvement of PAF-...
Article
Full-text available
Paf-acether (paf) is a phospholipid cytokine alloted with potent inflammatory and immunoregulatory properties. Recent reports indicated that in human B cell lines, paf modulated both early and late activation events. In our study, we showed that four of six human B cell lines specifically bound [3H]paf irrespective of the stage of differentiation,...
Article
Full-text available
Platelet-activating factor (PAF) has been implicated in the pathogenesis of acute inflammatory and ulcerative diseases of the upper gastrointestinal tract. In the present study, we compared the gastric output of PAF and its precursors with gastric acid output, in patients with various upper gastrointestinal tract diseases and healthy controls. PAF...
Article
Full-text available
Platelet activating factor (PAF-ACETHER or PAF) and precursors of platelet activating factor were investigated in 26 patients with acute Crohn's disease and in 10 healthy controls. Platelet activating factor, lyso platelet activating factor, and alkyl acyl glycerophosphocholine, were determined in colonic mucosal biopsies in patients with acute Cro...
Article
Full-text available
We recently observed that external Na+ inhibited the IgE-dependent human basophil histamine release (HR) in normal subjects. In this article we report differences in the Na+ effect on basophil HR between normal subjects (n = 16) and age matched patients with allergic rhinitis (AR) (n = 18). As expected, in vitro anti-IgE-stimulated basophils from t...
Article
The effects of protamine (6 mg kg-1) injected after heparin (5 mg kg-1) have been studied in five groups of five New Zealand white rabbits. Group I was treated with the sequence heparin-protamine and group II with protamine alone. The animals of groups III and IV received respectively intravenous indomethacin (3 mg kg-1) and BN 52021 (3 mg kg-1), a...
Article
Full-text available
Paf is a phospholipid mediator present in human skin which induces inflammatory events, such as neutrophil infiltration and increased vascular permeability. Recent data suggest that cutaneous cells, such as fibroblasts and keratinocytes, produce paf and that paf is released during allergic cutaneous reactions. It is tempting to speculate that paf m...
Article
Activated human T cells via the CD2 or the CD3 pathways exhibited a higher capacity than resting T lymphocytes to incorporate and metabolize [3H]pafacether (paf) at 37 degrees C. Resting T lymphocytes lacked specific binding capacity for paf, yet high-affinity paf receptors (paf-R) were induced on CD3- or CD2-dependent activation. This up-regulatio...
Article
The potent inflammatory mediator PAF-acether (PAF = platelet-activating factor) can produce the same hemodynamic and hematological effects as protamine infusion. In 10 patients, blood PAF and precursor levels were measured in the left atrium, the pulmonary and the radial artery before and after protamine reversal of heparin during coronary artery b...
Article
Full-text available
PAF-acether (PAF) is a phospholipid mediator with potent biological effects on the digestive tract. We report the presence of PAF in stool of patients with active Crohn's disease (39.1 +/- 13.5 ng/g of stool, mean +/- SEM, N = 19) and its absence in patients with irritable bowel syndrome with diarrhea and diarrhea with malabsorption. Fecal PAF acet...
Article
Paf-acether (paf) is a naturally occurring phospholipid involved in inflammatory processes. The presence of paf, its precursor lyso paf, and lipo-paf has been determined in blood and synovial fluid from 13 patients with rheumatoid arthritis (RA), 11 with spondylarthropathies, eight with other inflammatory rheumatisms, 13 with chondrocalcinosis, 15...
Article
Full-text available
Na+ and K+ are the major extra- and intracellular cations, respectively. We have thus studied the role of these ions on human basophil histamine release by modifying their transmembrane gradients or by increasing membrane ion fluxes using ionophores. 1) When external Na+ (reduced to 4 mM) was replaced by the nonpermeating Na+ substitute N-methyl-D-...
Article
A solid-phase enzyme-linked immunosorbent assay (ELISA) for determining human serum cystatin C is described. In 50 normal samples, cystatin C concentration was 1247 +/- 224 micrograms/L (mean +/- SD) which is in agreement with previously reported levels. Serum levels of cystatin C and beta 2-microglobulin (beta 2-M) were investigated in a time-cour...
Article
Paf-acether (platelet-activating factor) is a phospholipid described as a potent mediator of inflammatory response. We have recently shown that the level of paf bound to lipoproteins was significantly higher in the serum from patients with rheumatic diseases, compared to that of control subjects. In serum, paf is inactivated in part by a paf acetyl...
Article
Full-text available
In previous studies we observed that in vitro histamine release from human basophils could be dissociated from the loss of affinity of basophil granules for a cationic dye, toluidine blue. In the present study we further explored the intracellular signals leading to the decrease in toluidine blue positive basophil (TB+) numbers, with or without his...
Article
Infusion of paf-acether (paf, first described as platelet-activating factor) into animals stimulates glycogenolysis and lipolysis and decreases insulin levels. This study reports a 50-fold increase in blood levels of paf in patients with Type 1 insulin-dependent diabetes mellitus without micro or macrovascular complications (1.07 +/- 0.42 ng/ml, n...
Article
The aetiology and the pathogenesis of inflammatory bowel disease are unclear. New data indicate that the alkyl-phosphoglyceride paf-acether (PAF) could play a role in the development of gastrointestinal damage. This paper reviews the methodologic constraints on PAF research, the effects of PAF in the digestive tract of animals, and PAF production i...
Article
It was recently shown that paf-acether (paf) synthesized in different cell types remains partly cell-associated. In the present work, we tested the hypothesis that cell-associated paf might in fact remain exposed on the external plasma membrane and be able to exert its biological functions. Human polymorphonuclear neutrophils (PMN), stimulated with...
Article
The role of paf-acether (paf), a phospholipid cytokine, in the modulation of human B cell function was investigated. Paf, from 1×10−5 M to 10−6 M, decreased B cell proliferation induced by both phorbol myristate acetate (PMA) and anti-IgM antibodies (anti-IgM Ab). By contrast, 1×10−7 M to 1×10−9 M paf enhanced PMA triggered, but not anti-IgM trigge...
Article
Platelet-activating factor-acether (PAF-acether) presence was investigated in 27 human follicular fluids (FFs). Aggregation of washed rabbit platelets was used to measure PAF-acether. Data were compared using Student's t-test. Follicular fluids came from the in vitro fertilization program at Antoine Béclère Hospital, and PAF-acether was assayed at...
Article
Platelet-activating factor is an endogenous phospholipid produced by a wide variety of inflammatory cells. Platelet-activating factor induces severe pathological changes in various organs and, among numerous potent effects, causes bowel necrosis. Pouchitis is a poorly understood complication of ileoanal pouch anastomosis which occurs in patients wh...
Article
Full-text available
Human basophil activation was demonstrated by histamine release (HR) and by the decrease of the toluidine blue-positive basophils (TB+). In four experimental systems, TB+ number decreased in the absence of HR (1) in basophils from atopic subjects stimulated by allergen concentrations below the threshold for HR, (2) in basophils sensitized by anti-2...
Article
Paf-acether (platelet-activating factor, paf) is one of the most potent inflammatory mediators synthesised by and acting on most inflammatory cells. Paf causes gastric ulcerations and ischemic bowel necrosis. Recently, we described the presence of paf in stools of patients bearing ileal pouch-anal anastomosis with pouchitis. These findings prompted...
Article
Human isolated lung preparations were passively sensitized using mouse monoclonal dinitrophenyl (DNP)-specific IgE antibodies. The contractile response to antigen (DNP-bovine serum albumin; DNP-BSA) was approximately 80% of the histamine response (50 microM: 0.20 +/- 0.03 g/mm2) in bronchial muscle preparations. In passively sensitized pulmonary va...
Article
The production of the inflammatory mediator paf-acether (paf) from human epidermal cells was investigated in vitro. Human epidermal cells, freshly isolated from normal skin or in culture, were incubated in Tyrode's buffer containing 0.25% lipid-free bovine serum albumin in the presence of 2 microM calcium ionophore A23187, at 37 degrees C, for 1 to...
Article
Full-text available
Clinical studies suggest that Helicobacter pylori may play a role in the pathogenesis of gastroduodenal ulcers in man but direct evidence of mucosal injury by this microorganism is still lacking. Paf-acether (paf) causes a number of disorders including ischaemic bowel necrosis and gastroduodenal ulceration. Since paf is produced by Escherichia coli...
Article
Antigen stimulation of cultured bone-marrow-derived mast cells sensitized with specific monoclonal IgE induced cell degranulation and paf-acether (paf; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) biosynthesis via the deacylation/acetylation (remodelling) pathway. Phorbol myristate acetate (PMA; 20-100 ng/ml) triggered only acetyltransferase act...
Article
Full-text available
The role of IgG4 antibodies in allergic disorders is suspected. Yet, their presence on human basophil membrane has not been demonstrated and the mechanism of the degranulation induced by anti-IgG4 antibodies remains unclear. As previously reported, we observed that monoclonal anti-IgG4 (10 to 100 micrograms/ml) induced histamine release in the pres...
Article
In the present report, we further explored the mechanisms by which 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine (paf-acether), a phospholipid mediator of inflammation inhibited PHA-induced CD4+ cell proliferation. Evidence was obtained that CD4+ cells stimulated with either PHA or immobilized OKT3 in the presence of paf at concentrations that blo...
Article
Full-text available
Association of platelets and neutrophils is frequently observed within thrombi or inflammatory sites. Interactions between these two cell populations have been reported for the production of several mediators of inflammation such as hydrogen peroxides or leukotrienes. Another potential mediator of thrombosis and inflammation is paf-acether, which i...
Article
Isolated heart preparations were prepared from guinea-pigs passively sensitized with mouse anti-DNP monoclonal IgE to study hemodynamic parameters and histamine release upon antigen challenge (DNP-BSA). In the best experimental conditions a triphasic response (increase, decrease, increase) in heart rate and in coronary flow occurred during 10 minut...
Article
Comparison between holoxenic and axenic mice led to the conclusion that the presence of an intestinal microflora produced a decrease in wall paf in conventional mouse caecum, whereas an increase in wall lyso-paf and alkyl-acyl-glycerophosphocholine (A-A-GPC) content was noticed. By contrast, the presence of flora had no significant incidence on wal...
Article
In the present report we further explored the role of paf-acether (paf), a phospholipid cytokine, in the modulation of T cell activation Induced via the CD2 and the CD3 pathways. Evidence was obtained that paf inhibited T cell proliferation Induced by Immobilized CD3 mAb (OKT3I), but potentiated that Induced by a combination with the CD2 mAb, anti-...
Article
The chapter presents a study on bioassay of paf-acether by rabbit platelet aggregation. In the case of paf-acether (PAF), the method of choice is a bioassay, because the immunoassays that are now being developed have not yet proved their usefulness in day-to-day use in the research laboratory. Physicochemical methods are hampered by the very low pa...
Article
The effects of Ketotifen and disodium cromoglycate were investigated on human and rabbit platelet activation. Ketotifen inhibited dose-dependently human and rabbit platelet aggregation. The paf-acether pathway was the most markedly influenced by Ketotifen in human and rabbit platelets (IC50 = 38.8 +/- 7.7 microM and 7.2 +/- 4.5 microM respectively)...