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D de Prost

Publications and source records attributed to D de Prost.

48 records · Page 3Linked to original sources
PubMed1988

Binding of an anti D dimer monoclonal antibody to endotoxin-activated monocytes. Demonstration by immunogold-silver staining.

Blood monocytes exposed to a variety of stimuli, of which endotoxin is a potent one, produce and express on their membrane a procoagulant activity (PCA) which can trigger the formation of pericellular fibrin. We have developed an immunogold silver method using a monoclonal anti-D dimer antibody to detect the presence of crosslinked fibrin in derivatives on the monocyte membrane. The in vitro PCA of endotoxin-stimulated monocyte was shown to correlate significantly with the number of D dimer-positive monocytes. We suggest that this method could be used to identify activated monocytes expressing increased PCA.

Antibodies, Monoclonal↗
PubMed1987

Measurement of low molecular weight heparin ex vivo activities in clinical laboratories using various anti-Xa assays: interlaboratory variability and requirement for an agreed low molecular weight heparin standard.

The only sensitive and convenient assay to assess the biological activity of low molecular weight heparins (LMWHs) is based on the potentiation of activated factor Xa inhibition. Several procedures for measuring the socalled anti Xa activity have been proposed. In this collaborative study including eight laboratories, we have used four different assays (three amidolytic and one clotting based methods) for measuring the anti Xa activity of ex vivo samples obtained after injecting three different LMWHs. The dispersion of the results obtained by calibration against standard heparin could be reduced by using any of the three LMWHs for calibration. A coefficient of variation less than 0.20 between values obtained in different laboratories using a variety of methods seems acceptable. However it is necessary to refer to a common international standard for expressing the results in units and to define, for each of the three products, the therapeutic range.

Factor Xa↗
PubMed1987

Enhanced glomerular procoagulant activity and fibrin deposition in rats with mercuric chloride-induced autoimmune nephritis.

The mechanism involved in glomerular fibrin deposition was investigated during mercuric chloride (HgCl2)-induced autoimmune glomerulonephritis in the Brown Norway rat. To ascertain whether the local hemostatic system was activated secondarily to the immunological conflict, the ability of glomerular lysates to induce coagulation in vitro was assessed in treated and control rats. Glomerular procoagulant activity (PCA) of HgCl2-injected rats was measured on day 12 (latent phase of the disease), day 20 (acme), and days 32 and 42 (recovery phase) after the first mercury injection. PCA rose 3-fold (p less than 0.02) at day 20 and then almost returned to control values. Proteinuria, PCA, and the incidence of glomerular fibrin deposits peaked concomitantly at day 20. Glomerular PCA was characterized as thromboplastin. The number of Ia positive cells detected by monoclonal OX-6 antibody was not different from the control number at any phase of the disease; the number of macrophages per glomerular section detected by electron microscopy at day 20 in HgCl2-injected rats was 1.80 +/- 0.60, versus 0.30 +/- 0.11 in the controls. No correlation was found between glomerular PCA and either the number of monocytes/macrophages or of Ia-positive cells present in the glomeruli. Since glomerular PCA was maximal at the onset of fibrin formation in the glomeruli and then decreased toward its basal level, and since the fibrin disappeared, it is concluded that increased production of thromboplastin by glomeruli, with activation of the extrinsic coagulation pathway, may contribute to intraglomerular fibrin deposition in HgCl2-induced glomerulonephritis.

Animals↗
PubMed1985

Pentosane polysulfate: the effect on hemostasis of a continuous 3-day infusion.

Pentosane polysulfate (PP) is a sulfated polysaccharide known to exhibit anticoagulant properties that are in part independent of antithrombin III activity. These effects have only been studied in vitro or after single injections in healthy subjects. Our objective was to evaluate the modification of hemostasis induced by a 3-day continuous infusion of PP (4 mg/kg body weight/24 hr) in 10 subjects. No hemorrhagic complication was observed in any patient. Bleeding time was not modified by the infusion, despite a slight decrease in the platelet number. Among the other parameters measured, the automated partial thromboplastin time, prothrombin time, and anti-Xa activity were the most affected by PP. The kinetics of their modifications were quite uniform: clotting times and the anti-Xa effect increased gradually until reaching steady state 24 hours after the start of the infusion. A progressive return to the pretreatment level was then observed during the 6 hours after the end of the infusion. A significant decrease in the factor V concentration was found at day 4. Finally, in contrast with other reported results, no activation of fibrinolysis was induced by PP under the conditions we used, which suggests that discontinuous administration or the route of administration of the drug influences the fibrinolytic effect. In conclusion, we show the excellent tolerance of continuous infusion of PP, detail the modifications in biologic parameters of hemostasis during and after PP infusion, and demonstrate that PP decreases factor V activity.

Adult↗
PubMed1983

Intra-coronary thrombolysis with streptokinase or lys-plasminogen/urokinase in acute myocardial infarction: effects on recanalization and blood fibrinolysis.

Forty-two patients with total occlusion of a coronary vessel were treated with intracoronary fibrinolytic agents. Four therapeutic protocols were compared: group I received streptokinase (SK) as a continuous infusion; group II and III received SK as a bolus at different doses and group IV received lysplasminogen (Pg) plus urokinase (UK); maximal doses were 350,000 IU of SK and 250,000 IU of UK plus 75 microK of Pg. Thrombolysis was assessed by coronary angiography. Coagulation studies were performed prior to, 15 min and 6 hr after the end of the thrombolytic treatment. Recanalization was achieved in 27 of the 31 SK-treated patients (87%) and in 7 of the 11 Pg-UK-treated patients (63.6%). The recanalization frequency was the same in the three SK-treated groups, even though when SK was administered as a bolus, the dose was significantly less than when administered on a continuous infusion. Although systemic fibrinolysis occurred in all 4 groups of patients, this effect was less pronounced in the UK-treated patients than in the three SK-treated groups. This study also shows that recanalization can be achieved with a dose of SK lower than the anti-SK antibody level. Haemorrhagic side effects were minimal in all patients studied. Severe defibrination is usually considered a risk of haemorrhage. These preliminary results suggest that bolus injection of SK or the use of UK plus lys-Pg can reduce the level of defibrination and thus the haemorrhagic risk.

Adult↗
PubMedDate not supplied

[Role of free radicals in ischemia and myocardial reperfusion. The oxygen paradox].

The monovalent reduction of oxygen yields two reduced intermediate forms: the dioxide anion (O2), hydrogen peroxide H2O2, and the hydroxyl radical (OH.) several of which appear as radicals. Under normal conditions, the concentration of free oxygen radicals in the tissues is closely controlled because of the serious cell lesions which an accumulation of these radicals can cause. The aim of this paper was to discuss the origin and role of free oxygen radicals in cell lesions induced by myocardial ischemia/perfusion as well as results obtained in different experimental models using methods to trap these radicals. Overall these experimental results are encouraging and appear to offer new therapeutic possibilities which, however, have been evaluated only barely in man.

Coronary Disease↗