Publications by authors named "Pontet M"

Aims: To determine whether plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, a marker for cardiac failure and potentially for the severity of coronary artery disease (CAD), predicts silent myocardial ischaemia (SMI) and silent CAD in asymptomatic high-risk diabetic patients.

Methods: Five hundred and seventeen asymptomatic diabetic patients with > or = 1 additional cardiovascular risk factor but without heart failure were prospectively screened between 1998 and 2008 for SMI, defined as an abnormal stress myocardial scintigraphy, and subsequently for significant (> 70%) angiographic CAD. The 323 patients with interpretable echocardiography and for whom NT-proBNP was measured were included in this analysis.

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We have previously reported that alpha-fetoprotein (AFP) inhibits infection of human monocyte-derived macrophages (MDM) by R5-HIV-1 strains and that a peptide mimicking the clade B HIV-1 gp120 consensus V3 domain (V3Cs) binds to CCR5. We demonstrate here that AFP binds high- and low-affinity binding sites of MDM, characterized, respectively, by 5.15 and 100nM K(d) values.

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Hypermethylation is an important mechanism for repression of tumor gene suppressor in cancer. The drug 5'-azacytidine (AZC) has been used as demethylating agent to induce the expression of previously silencing genes. In the present work, we attempted to determine, using proteomics, the changes in protein expression profiles following a treatment of an Epstein Barr virus (EBV)-negative Burkitt lymphoma (BL) cell line DG 75.

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The BPP (protein biochemistry and proteomics) two-dimensional electrophoresis (2-DE) database (http://www-smbh.univ-paris13.fr/lbtp/Biochemistry/Biochimie/bque.

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Lymphoblastoid cell lines correspond to in vitro EBV-immortalized lymphocyte B-cells. These cells display a suitable model for experiments dealing with changes in protein expression occurring upon B-cell differentiation, after drug treatment, or after inhibition of some transcription factors. For all these reasons we have undertaken an effort aimed at developing a hematopoietic cell line protein two-dimensional electrophoresis (2-DE) database, containing B-lymphoblastoid 2-DE maps.

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A procedure is described for the determination of the affinity constant between a fluid-phase biotinylated antigen and a solid-phase monoclonal antibody. This procedure allows evaluation of the efficiency of an antibody as a coated tool for an immunoassay. For this purpose, the biotinylation of the antigen and its further quantitative measurement by streptavidin-peroxidase led to a single reversible interaction, the binding affinity of which greatly determines the quality of the assay.

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Antisera raised against galectin-1 exhibit crossreactivities with other galectins or related molecules. In order to overcome this problem, a monoclonal antibody to human brain galectin-1 was obtained by selecting clones without reactivity toward galectin-3. This mAb specifically bound galectin-1 of various animal origins but neither galectin-2 nor galectin-3.

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Galectin 1 (GAL1) is a beta-galactoside-binding lectin involved in cell cycle progression. GAL1 overexpression is associated with neoplastic transformation and loss of differentiation. The gene encoding for human GAL1 resides on chromosome 22(q12; q13), and its expression is developmentally regulated.

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Vertebrate soluble beta-galactoside-binding lectins form a growing protein family that recently have been named galectins. Seven different galectins have been sequenced and characterized in mammals, and there is compelling evidence for the existence of other members of this lectin family. Three among six galectins are homodimers with (i) an identical subunit of a relative molecular mass of about 14500, and (ii) amino acid sequence homologies giving rise to possible immunochemical cross-reactivities.

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Horseradish peroxidase is often used as an antibody-coupled enzyme and several procedures have been developed to obtain IgG-peroxidase conjugates. The most widely used are coupling with periodate or glutaraldehyde. To compare the efficiency of these methods, the authors conducted periodate coupling or glutaraldehyde coupling in one or two steps, using the same batches of peroxidase, C-reactive protein (CRP) and anti-CRP monoclonal antibodies to develop a specially sensitive Elisa for CRP.

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Human serum amyloid P component (hSAP) and human C-reactive protein (hCRP) are normal serum constituents related to the pentraxin family of plasma proteins. hSAP has morphological and immunochemical identity and extensive sequence similarity to the amyloid P (AP) component found in normal tissues and particularly in amyloid deposits. hCRP and its proteolytic products have been previously shown to bind and to interact with various types of human leukocytes.

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The monitoring of inflammatory activity in patients with a high level of estrogen is controversial because the significance of a raised estradiol level on C-reactive protein (CRP) concentrations is a debated question. This prompted us to assay CRP by a sensitive Elisa in a sample of 30 patients with ovarian stimulation for in vitro fertilization, thus with high levels of estradiol. For 15 of these women, six to nine plasma samples were analyzed allowing a kinetic study of plasma levels of CRP, estradiol and sex steroid-binding plasma protein (SBP).

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In the acquisition of protection against malaria, the role played by nonspecific factors, some being part of the cascade effect of cytokines, has to be considered. The C-reactive protein, a major acute phase reactant secreted by interleukin-1 stimulated hepatocytes, has an effect on the hepatic development of Plasmodia, both by preventing penetration of the sporozoite into the hepatocyte and by blocking parasite division through an antibody-like effect. This latter effect confirms the potential interest of targeting the uninuclear form of the parasite.

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Treatment of human neutrophils with C-reactive protein (CRP) causes a concentration-dependent in the extent of activation of superoxide production and of granule secretion, induced by phorbol-12-myristate-13-acetate (PMA) or N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLF). The same treatment also causes a significant reduction in the degree of PMA- and fMLF-stimulated phosphorylation of several cell proteins. These include the proteins of 43-47 kDa, whose extent of phosphorylation correlates with the activation of superoxide production and of secretion.

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Investigation of the effect of C-reactive protein (CRP), an acute-phase reactant, on the functional capacities of human neutrophils was carried out as the basis for elucidating the biological function of C-reactive protein. An initial stimulation at low concentrations, followed by inhibition of superoxide production, and secretion of vitamin-B12-binding protein in the presence of two stimulants, phorbol myristate acetate and concanavalin A, and of neutrophil chemotaxis with increasing concentration of CRP was observed. Correlation between modulation of cell function, at least at relatively high CRP concentrations (greater than 50 micrograms/ml) and an increase in the intracellular level of cAMP is suggested.

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The binding of radiolabelled 125I-CRP to human neutrophils has been characterised according to pH, temperature and time dependence. The binding of 125I-CRP was saturable, very fast (less than 2 min at 22 C), and the labelled protein was displaced by unlabelled CRP and aggregated human IgG. The dissociation constant was 3.

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Peptides containing Lys-Pro-Arg or Thr-Lys-Arg segments corresponding to various regions of human C-reactive protein were synthesized. The peptides prepared were composed of amino acid residues, 37-58, 51-58, 173-187 and 181-187 of C-reactive protein. The relationship between C-reactive protein, its synthetic fragments and tuftsin (Thr-Lys-Pro-Arg) was investigated in binding studies, enhancement of phagocytosis and change in cyclic nucleotide levels of mouse macrophages.

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In rats infected with the parasite Schistosoma mansoni, the concentration of C-reactive protein in the serum increases after the lung stage of infection and is at its highest at the time of terminal worm rejection. The peak of platelet-mediated cytotoxicity induced by infected serum that has been heated (and is free of immunoglobulin E) as well as the time course for the development of platelet cytotoxic activity in infected rats was found to be correlated with the concentration of C-reactive protein. Rat and human platelets treated with homologous serum obtained during an acute phase of inflammation or with purified C-reactive protein were able to kill the immature forms of the worm in vitro.

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A new rat serum protein has been isolated by affinity chromatography using ethanolamine- or phosphoethanolamine-substituted agarose gels. This protein has the morphological and functional characteristics of serum amyloid P-component and C-reactive protein. It comprises C5 cyclic symmetry structure with non covalently cross-linked subunits which have calcium-dependent binding sites.

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The preparation of rabbit C-reactive protein (CRP) involves a single step affinity chromatography. This preparation takes advantage of the calcium-dependent affinity of CRP for an agarose gel bearing 2-aminoethanol dihydrogen-phosphate as a ligand. A prior chromatography on agarose gel without the ligand allows the uptake of the serum amyloid P-component (SAP).

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