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J L Wautier

Publications and source records attributed to J L Wautier.

At least 19 recordsLinked to original sources
PubMed1992

[Contact factors in severe sepsis].

Coagulation and fibrinolysis are not activated in an isolated system but it involves numerous interrelations with the kininogen-kinin pathway and the complement. In severe sepsis, substances released by microorganisms, notably lipopolysaccharides, can activate the contact system, and particularly in such circumstances, contact activation probably plays a role in the occurrence of haemodynamic changes and consumption coagulopathy. Evidence of kininogen-kinin pathway activation as assessed by biological investigations in patients with severe sepsis, could lead to the therapeutical use of natural or synthetic protease inhibitors.

Apoproteins↗
PubMed1992

Procoagulant activity of endotoxin or tumor necrosis factor activated monocytes is enhanced by IgG from patients with lupus anticoagulant.

The effect of lupus anticoagulant (LA) positive plasma on the expression of human monocyte procoagulant activity (PCA) was studied. LA positive plasma were able to enhance the endotoxin or TNF alpha induced monocyte associated PCA. The monocyte PCA had the characteristic of tissue factor activity (factor VII, factor X dependence). The enhancement of monocyte PCA could be confirmed using purified LA positive IgG. The stimulating effect was supported by the F(ab')2 fragments.

Adult↗
PubMed1992

Molecular mechanism of blood monocyte adhesion to vascular endothelial cells.

The blood monocytes adhere to endothelial cells unstimulated and after stimulation by interleukin-1, tumor necrosis factor or other mediators. This process is mediated through specific molecules on both endothelial cells and monocytes. Using specific monoclonal antibodies and molecular cloning several families of molecules involved in leukocyte endothelial cell interaction have been defined. Leukocyte adhesion molecules include the three beta 2 integrins (CD11/CD18 molecules), VLA-4 and the L-Selectin. E-Selectin (ELAM-1), P-Selectin (GMP-140) and receptors of the immunoglobulin superfamily (ICAM-1, ICAM-2 and VCAM-1) are expressed on endothelial cells in basal conditions and after activation. It has been shown that these adhesive molecules are involved in blood monocyte adhesion to endothelial cells. Monocytes from patients with diabetes mellitus had an increased adhesion to endothelial cells in culture. As estimated by flow cytometry CD11b/CD18 expression on diabetic monocytes was increased. Pentoxifylline reduced CD11b/CD18 expression on normal and diabetic monocytes. This effect was associated to a decrease in monocyte adhesion to endothelial cells.

Cell Adhesion↗
PubMed1992

Inhibition of human endothelial cell growth by human monocytes in coculture.

Previous studies conducted in different experimental models have shown that human monocytes (Mo) possess both stimulating and inhibiting factors for endothelial cell growth. Since Mo are frequently found in the vicinity of endothelial cells, we examined the direct effect of human peripheral blood Mo on the proliferation of human umbilical vein endothelial cells (HEC) in in vitro culture systems. Mo obtained either by counter centrifugation elutriation or by selective adhesion on gelatin-autologous plasma or purified fibronectin coated plastic surfaces inhibited HEC growth as determined by HEC count or 3H-methyl thymidine incorporation. This growth inhibitory effect was dependent on the number of monocytes: 50% inhibition of 3H-thymidine uptake by HEC was achieved for a Mo-EC ratio of 1:4. Mo isolation by selective adhesion on gelatin-plasma resulted in a significantly higher inhibitory effect (p less than 0.02) than that observed with Mo isolated on fibronectin coated surfaces or by elutriation techniques, suggesting a possible stimulation of Mo by contact with gelatin-plasma. Endothelial cell growth factor plus heparin did not reverse this inhibition of HEC growth. Results obtained in diffusion chamber and coculture systems showed that soluble products of Mo origin can inhibit HEC proliferation but the inhibition was greater when Mo and HEC were in contact. The effect was not due to cytotoxicity as evaluated by cell counting and 51Chromium release from HEC. These in vitro results suggest that normal monocytes could exert a regulatory role on the proliferation of endothelial cells.

Animals↗
PubMed1992

von Willebrand factor antigen, tissue-type plasminogen activator antigen, and risk of death in human immunodeficiency virus 1-related clinical disease: independent prognostic relevance of tissue-type plasminogen activator.

Tissue-type plasminogen activator, von Willebrand factor, and plasminogen-activator inhibitor type 1 plasma levels were measured at first consultation in 85 consecutive patients infected with human immunodeficiency virus. Patients were assigned to three groups according to clinical status: mild disease group, intermediate group, and acquired immunodeficiency syndrome group. Significant differences were found in von Willebrand factor, tissue-type plasminogen activator, and plasminogen-activator inhibitor type 1 plasma levels among the three groups: severe clinical status was associated with higher von Willebrand factor, tissue-type plasminogen activator, and plasminogen-activator inhibitor type 1 plasma levels. Significant correlations were found among these three parameters, such known biologic prognostic indicators of human immunodeficiency virus infection as IgA, anti-p24 antibodies, p24 antigenemia, CD4+ lymphocytes, beta 2-microglobulin, and the clinical status. The prognostic relevance of plasma von Willebrand factor and tissue-type plasminogen activator levels at the time of entry into the study was then investigated in a cohort of 65 of the 85 patients who had follow-up during a median period of 22 months. The median survival time for all patients was 39 months after the first consultation. A plasma von Willebrand factor level greater than 200% of the control value had a positive predictive value of 86% for determining nonsurvivors; the median survival time for such patients was 9 months after the first consultation. A positive predictive value of 100% in recognizing nonsurvivors was found for tissue-type plasminogen factor plasma levels greater than 20 ng/ml; the median survival time for these patients was 2 months after the first consultation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Immunological study of platelet glycoproteins and alloantigens in families of patients with Glanzmann's thrombasthenia.

To explore the genetic transmission of Glanzmann's thrombasthenia (GT) we conducted a study of platelet glycoproteins and antigens using monoclonal and polyclonal antibodies and cytofluorometry. Twenty-one members of 4 different families in which at least one member was affected with GT were explored. The reactivity with AP2 (anti-GP IIb-IIIa complex, CD41a), AP3 (anti-GP IIIa) and antibodies against HPA-1a (PLA1) and HPA-3a (Leka) was lower than 5% in the platelets of 5 patients with GT type I. Nine obligatory carriers of the GT trait were tested by the same technique. The mean values of reactivity expressed as per cent of normal with AP2 (anti-CD41a) and AP3 (anti-GPIIIa) were 58.3 +/- 3.6% and 58.6 +/- 3.6% respectively, while the frequencies of HPA-1a (PLA1) and HPA-3a (Leka) negativity were 0/9 and 4/9 respectively. When both antigens were expressed they were detected at reduced levels. These results indicate that cytofluorometry is a simple technique for GT detection, but this method would nevertheless not appear to be sufficiently accurate to identify obligatory carriers in a general population.

Antibodies, Monoclonal↗
PubMed1991

Platelet membrane glycoproteins and platelet functions during storage in the presence of a proteinase inhibitor.

The effect of the proteinase inhibitor aprotinin on membrane glycoproteins and functions of platelets stored for 5 days in platelet-rich plasma was tested. Platelet membrane glycoprotein content was determined by flow cytometry or immunoblot techniques using different monoclonal antibodies. ADP- and ristocetin-induced platelet aggregation and adhesion to collagen were tested in parallel. Using the flow-cytometry technique i) a progressive decrease in the percentage of platelets reacting with the different monoclonal antibodies was observed during storage ii) a 30% reduction of the GPIb mean fluorescence intensity (MFI) was observed after 5 days storage while the MFI of the GP IIb-IIIa complex was not modified. Using the immunoblot technique, a decrease in the amount of both the GPIb alpha and the component of Mr 100,000 was observed, while a 50,000 Mr fragment appeared progressively. Platelet adhesion and aggregation were reduced after 24 hours of storage. Aprotinin prevented neither the GPIb alpha reduction nor the modifications of the functions of human platelets stored in their autologous plasma.

Aprotinin↗
PubMed1991

Association of autoimmune thrombocytopenic purpura (AITP), Graves' disease and ovarian carcinoma.

We report here the case of a patient suffering sequentially from autoimmune thrombocytopenic purpura (AITP), Grave's disease and an ovarian carcinoma. An autoimmune mechanism was indicated by the presence of platelet associated immunoglobulins and the detection of antithyroid microsomal antibodies. However, the exact mechanism associating these autoimmune manifestations with the ovarian tumour remains unexplained. Specific therapy for hyperthyroid led to a moderate increase of the platelet count. But complete remission of AITP now lasting for more than eight years was only obtained by ablation of the ovarian tumour.

Autoimmune Diseases↗
PubMed1991

Normal expression of the adhesive structure Mo-1 on monocytes from patients with Glanzmann's thrombasthenia.

The glycoprotein complex GPIIb-IIIa of the platelet membrane and CD18 of the monocyte membrane have been established as being the central figure for the adhesion processes of the corresponding cells. The molecular structure of these 2 GPs bears some similarities. It was proposed recently that LFA-1 and Mo-1 (CD18 family) and GPIIb-IIIa might be encoded by the same gene. For this purpose, we studied the expression of Mo-1, Mo-2 (as control) receptors on monocytes and GPIIIa and GPIIb-IIIa on platelets of two GT patients as compared to normal healthy subjects. Monoclonal antibodies anti Mo-1, MO-2, AP-3 and AP-2 were used to measure the expression of the respective antigens by indirect immunofluorescence procedure. The fluorescence of the labelled cells was analysed with an Ortho Cytofluorograph 50-H. The resulting Mean Fluorescence Intensity (MFI) values of AP-2 and AP-3 showed that the patients had a total absence of GPIIb-IIIa antigens. However, Mo-1, as well as those of control Mo-2, in patients (MO-1: 672 and 716; Mo-2: 453 and 637) were similar to that of normal subjects (Mo-1: 735 +/- 74; Mo-2: 585 +/- 35; mean +/- SEM). Therefore, the normal expression of Mo-1 receptors on the monocytes of Glanzmann's thrombasthenia patients suggests different genomic regulations for Mo-1 antigens on the monocyte and GPIIb-IIIa complex on the platelet.

Cell Adhesion Molecules↗
PubMed1991

[Leukocytes and vascular lesions].

The participation of leukocytes in the development of vascular disorders has been observed under various circumstances. Leukocyte activation occurs in extracorporeal blood circulation which lead to a pulmonary vascular sequestration and respiratory distress syndrome. Leukocytes could act on vascular components through at least two different pathways by releasing free oxygen radicals and proteases or by producing mediators such as interleukin 1, Tumor necrosis alpha, leukotrienes. Monocytes macrophages are present in the vascular wall at a very early stage of atherosclerosis. A majority of foam cells have been identified as macrophages loaded with lipids. Lymphocytes and monocytes are present in the atherosclerotic plaque. Leukocytes are also observed in the inflammatory lesion of vasculitis and experimentally activated lymphocytes can induce vasculitis. The molecular bases of leukocyte-endothelium interactions have been determined, and imply specialized molecules. Leukocyte Adhesion Molecule (LeucAM) appear to play a crucial role in leukocyte adhesion. On the endothelial cell side, endothelial cell adhesion molecule, intercellular adhesion molecule are receptors for leukocytes adhesion. They have been recently fully characterized. The better knowledge of leukocyte-vascular wall interactions offers new possible target for therapeutic agents.

Endothelium, Vascular↗
PubMed1990

Identification of an endothelial cell growth-inhibitory activity produced by human monocytes.

The control of endothelial cell proliferation is important in a variety of processes including wound healing and tumor-induced angiogenesis. We have observed that normal unstimulated human monocytes isolated from the blood can inhibit human endothelial cell proliferation. Monocyte-conditioned medium was fractionated by gel filtration chromatography, yielding a 175-fold enrichment of a growth inhibitory activity, designated monocyte-derived endothelial cell inhibitory factor (MECIF). MECIF was found to be protease sensitive, resistant to acid treatment, and heat labile. When conditioned medium was subjected to HPLC gel filtration, the inhibitory activity was eluted as a single peak with a molecular weight of 50-70 kDa. Several characteristics distinguish MECIF from previously described monocyte/macrophage-derived inhibitory factors. Unlike TGF-beta, MECIF is heat labile and does not induce a mitogenic response in growth-arrested normal rat kidney cells. In addition, polyclonal antibodies specific for TGF-beta or INF-gamma do not inhibit MECIF activity. MECIF preparations show low levels of TNF-alpha, insufficient to promote the observed growth inhibitory effect. MECIF activity on human endothelial cells was found to be dose dependent and reversible. MECIF also appeared to be target cell selective in that it did not significantly alter the growth of human smooth muscle cells or skin fibroblasts. These data suggest that monocyte-derived factors may play a key role in inhibiting endothelial cell proliferation.

Cell Division↗
PubMed1990

Leukocyte adhesion to endothelial cells.

The adhesion of leukocytes to endothelium is a physiological phenomenon which is the first step for leukocyte emigration. The adhesion can be dramatically increased in pathological situations such as inflammation and vascular diseases. The molecular basis of leukocyte-endothelium interaction has been largely investigated in the last ten years. Using monoclonal antibodies it is possible to characterize the leukocyte adhesion molecule (LeuCAM) also named CD11/CD18 complex. These molecules responsible for leukocyte adhesion are heterodimers consisting of a common beta subunit and different subunit CD11a/CD18 corresponding to LFA-1; CD11b/CD18 to Mac1/Mol; CD11c/CD18 to GP150-95. Beside these receptors, other leukocyte structures such as the fibronectin receptors are involved in the adhesive process. On the endothelial cell side specialized structures implicated in leukocyte adhesion have been identified. Structures like Intercellular Adhesion Molecule (ICAM) are expressed on endothelial cells in the absence of stimulation, while other receptors Endothelial Leukocyte Adhesion Molecule (ELAM) are only detectable on activated endothelial cells. Cytokines such as IL-1 induced the expression of ELAM, increased the number of ICAM and Human Leukocyte Antigens (HLA) DR, DP, DQ. In various pathological circumstances, namely extracorporeal circulation, Acute Respiratory Distress Syndrome (ARDS), hypercholesterolemia and diabetes mellitus increased leukocyte adhesion has been reported and is potentially responsible for vascular damage. Therefore, the modulation of leukocyte-endothelial cell interactions is a possible target for antithrombotic and antiatherosclerotic therapy.

Cell Adhesion↗