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Biomedical subjects

D Bourel

Publications and source records attributed to D Bourel.

34 records · Page 2Linked to original sources
PubMed1987

Flow cytometric quantitative evaluation of phagocytosis by human mononuclear and polymorphonuclear cells using fluorescent nanoparticles.

The use of fluorescent polymethacrylic nanoparticles (0.3 micron) as a flow cytometric reagent in the quantitative evaluation of phagocytosis by human mononuclear and polymorphonuclear cells is described. The preparation of the nanoparticles, by emulsion copolymerization of methacrylic monomers, and their physicochemical properties are briefly summarized. Nanoparticles coupled with a fluorescent agent (ethidium bromide) were used in a flow cytometric assay to study opsonin-independent phagocytosis by human polymorphonuclear cells and by human monocytes. The phagocytosis of nanospheres by monocytes was determined by flow cytometry from the fluorescence distribution and ingestion was visualized by scanning and transmission electron microscopy. One possible application of the fluorescent nanoparticles is the simultaneous analysis of cell surface antigens and cell phagocytic activity.

Acrylates↗
PubMed1987

A monoclonal antibody (Po66) directed against human lung squamous cell carcinoma immunolocalization of tumour xenografts in nude mice.

Po66, a mouse IgG1 monoclonal antibody, was produced by immunization against a patient lung squamous cell carcinoma. The tissue reactivity of the antibody was measured by a radioimmunological assay with enzymatically dissociated cells, by an immunofluorescence test on frozen tissue sections and by peroxidase-staining of paraffin sections. The antibody bound to lung squamous cell carcinoma, oesophagus carcinoma and, inconsistently to lung adenocarcinoma but not to the other tumours tested. Some normal tissues also reacted positively, in particular bronchial serous glands, oesophagus epithelium and renal distal and collecting tubules. In normal and malignant tissues showing epithelioid differentiation, Po66 bound to the intermediate maturation area. The antigen immunoprecipitated by Po66 from lung squamous cell carcinoma appeared as a single band with a molecular weight 47,000 to 50,000 daltons. Purified monoclonal antibody Po66 and an unrelated IgG1 immunoglobulin were labelled with radioactive iodine and injected i.v. into nude mice bearing subcutaneous xenografts of human lung squamous cell carcinoma. The localization index in the tumour was 3.3. Antibody labelled with 131I allowed gamma-scintigraphic imaging of the xenografts which were clearly outlined by days 9 to 11.

Animals↗
PubMed1987

Chronic liver iron overload in the baboon by ferric nitrilotriacetate. Morphologic and functional changes with special reference to collagen synthesis enzymes.

Two baboons receiving intramuscular injections of ferric nitrilotriacetate over a two-year period were compared with two control baboons. The results indicate that in iron-overloaded animals: liver iron excess was major (maximal liver iron concentration values of 42 mumol/100 mg dry weight for both animals vs 1.3 +/- 0.2 (mean +/- SD) in controls) and chronic (for 15 months liver iron concentrations were higher than 15); iron deposition, although less abundant than in sinusoidal cells, was pronounced within parenchymal cells; serum transaminase activities were markedly increased; rare foci of perisinusoidal fibrosis were observed in areas of massive iron overload; and a dramatic decrease in hepatic 4-prolyl-hydroxylase activity was found, in contrast with unchanged glucosyltransferase and galactosyltransferase activities. In conclusion these findings suggest that, in our model, chronic liver iron overload: exerts a marked biochemical cytolytic effect; and does not produce significant hepatic fibrosis, possibly related to an inhibiting effect of ferric nitrilotriacetate complex on 4-prolyl-hydroxylase activity.

Animals↗
PubMed1987

A European workshop to investigate technical problems of using HLA monoclonal antibodies in microcytotoxicity assays.

Various methods for controlling carryover from monoclonal antibodies (MCA) used in the microcytotoxicity assay to detect HLA antigens were investigated by 45 European laboratories. Carryover was demonstrated in most laboratories when using standard techniques (i.e. as for allo-antisera). Taking into consideration factors such as technical ease, time, accuracy and reagent availability, nearly half the participants selected the "no-touch" technique for adding cells and complement as being the best method for controlling carryover in their laboratory. (This method allows the needle of the Hamilton syringe to touch the oil but not the antibody in each well). Most participants (75%) thought that at least one diluent well was still necessary between each MCA well, even when using their preferred technique.

Antibodies, Monoclonal↗
PubMed1987

A common epitope between HLA-B27, -B13 and -B37 alloantigens defined by a monoclonal antibody.

An anti-HLA-B27 monoclonal antibody produced by the hybridoma technique is described. This BD.7 reagent is a cytotoxic IgM antibody. Its reactivity was studied by lymphocytotoxicity tests, indirect immunofluorescence tests and biochemical analysis against an extensive panel of peripheral blood mononuclear cells. All HLA-B27 positive samples, either from normal subjects or from patients with Ankylosing Spondylitis, were recognized by this reagent. Moreover, a cross-reaction was observed with HLA-B13 cells, and a new unexpected reaction with all HLA-B37 cell suspensions. The interest of such a reagent is discussed.

Antibodies, Monoclonal↗
PubMed1987

Murine monoclonal antibody suitable for use as an Rh reagent, anti-e.

The production by the hybridoma technique of a monoclonal antibody which behaves as an anti-e agglutinin is described. A reagent was made from ascitic fluid diluted in RPMI 1640 culture medium and bovine serum albumin. All red blood cells bearing the e antigen were agglutinated; no reactivity was recorded with untreated EE red cells suspensions. However, cross-reactivity was observed with enzyme-pretreated EE cells. The characteristics of this monoclonal antibody are described and are in accordance with the standard references.

Animals↗
PubMed1987

[Anti-CD3 monoclonal antibodies. Characterization and function].

Four anti-T lymphocyte monoclonal antibodies were produced by the hybridoma technique. Percentages of miscellaneous labelled cell suspensions, as profiles of fluorescent histograms, showed a reactivity of these 4 reagents quite comparable to that observed with anti-CD3 monoclonal antibodies. Labelling summation studies, cell-sorting studies and blocking experiments gave similar results as gave other anti-CD3 reagents. Biochemical study and functional tests: modulation effects and mitogenic properties, argued for the belonging of these 4 antibodies to the CD3 cluster. The actual data concerning the CD3 molecule are briefly resumed to underline the interest of such antibodies in the understanding of T-lymphocyte activation mechanisms during the immune response.

Animals↗
PubMed1986

A monoclonal antibody (3A33) that reacts with a mouse-specific epitope of Mac-1 antigen.

The 3A33 monoclonal antibody, obtained by fusing rat immune lymphocytes with mouse plasmacytoma cells, was directed against mouse macrophages. Antibody 3A33, a rat IgG2a, reacted with macrophages from all the mouse strains tested, with mouse blood monocytes and with 56% of bone marrow cells, but not with T lymphocytes. It immunoprecipitated an antigen with alpha and beta subunits, found to be identical to Mac-1 antigen after cross-absorption experiments with M1/70 monoclonal antibody. The two antigenic determinants of the Mac-1 molecule identified by the 3A33 and M1/70 antibodies both displayed reduced expression on inflammatory macrophages and comparable resistance to trypsin digestion. The sites of the determinants on this molecule seemed close together judging from the ability of both the 3A33 and M1/70 antibodies to block C3bi receptor sites and compete for cell binding. However, unlike antibody M1/70, 3A33 never reacted with human cells bearing Mac-1 antigen. Therefore, two closely related epitopes of the Mac-1 molecule - one specific for mouse and one common to mouse and man, were recognized by these monoclonal antibodies.

Animals↗
PubMed1985

Diminution of circulating polymorphonuclear leucocytes by administration of a monoclonal antibody reacting with granulocytes and monocytes.

The monoclonal antibody 3A35 which binds mouse polymorphonuclear leucocytes (PMN) and monocytes was injected intravenously (i.v.) into normal mice. A great diminution of circulating PMN was observed. The percentage of PMN passed through a minimum (2.5%) 20 min after antibody injection and returned to normal value (18.3%) within 24 h. After repeated daily injections, the ability of the antibody to induce granulopenia attenuated. Moreover, mice bearing the 3A35-producing hybridoma as an ascitic tumor had a normal percentage of blood PMN and a normal granulopoiesis as judged from bone marrow cytological examination. Thus, the monoclonal antibody produced a transitory diminution of PMN but could not induce a lasting granulopenia.

Animals↗
PubMed1984

Anti-HLA-A2 and -A28 monoclonal antibody: production and study of the cross-reaction.

An anti-HLA-A2 and -A28 monoclonal antibody, XV.17, has been prepared by immunizing a Balb/c mouse with PBL. This XV.17 monoclonal antibody is a cytotoxic IgM. Its reactivity was tested by lymphocytotoxicity test and indirect immunofluorescence technique, in parallel with an alloantiserum ORA having the same anti-HLA-A2, -A28 reactivity pattern, against different panels. Family studies were undertaken. Absorptions-elutions and cytofluorometry experiments were performed to study the cross-reaction. The XV.17 monoclonal antibody is cytotoxic against all the HLA-A2 and -A28 tested cells, and is absorbed by HLA-Aw23 and -Aw24 cell suspensions.

Animals↗
PubMed1984

An anti-mouse macrophage monoclonal antibody reacting with T-derived leukaemic cells.

Hybridomas secreting anti-mouse macrophage antibodies were obtained by fusing a murine plasmacytoma with lymphocytes of a rat immunized against mouse macrophages. An IgM, monoclonal antibody (3 A 35) reacted with mouse monocytes, macrophages and polymorphonuclear leucocytes. It did not bind appreciably to erythrocytes, platelets and unstimulated T or B lymphocytes. However, 3 A 35 bound to various murine T-derived leukaemic cells and to a small proportion of Con A-stimulated thymocytes. Cross absorption experiments confirmed the existence of a common antigenic determinant on macrophages and leukaemic cells. The possibility that 3 A 35 identified a previously described antigen common to macrophages and normal or leukaemic T cells was investigated. The antibody was tested against thymocytes and macrophages of various mouse strains, some congenic for H-2 or T1a. The 3 A 35-detected antigen was found to be different from Ly5, Tla and Qa and did not represent a I-J encoded allotypic specificity.

Animals↗
PubMed1983

Transformation of LMTK- cells with purified HLA class I genes. II. Serologic characterization of HLA-A3 and CW3 molecules.

The expression of two different HLA class I genes was observed after transformation of LMTK- cells. The corresponding class I molecules reacted differentially with monomorphic monoclonal antibodies (m.Ab). Absorption and elution studies of the human alloantibodies reacting with the transformed cells and cellular radioimmunoassay of these cells with polymorphic m.Ab resulted in the identification of HLA-A3 and CW3 molecules. These transformed cells were used to immunize C3H mice and induce the production of xenogeneic antisera, which, following absorption, showed polymorphic reactivity with human cells, suggesting that some of these sera could be used as typing reagents.

Animals↗
PubMed1982

A monoclonal antibody to the HLA-A3 alloantigen.

Monoclonal antibody production recognizing the HLA-A3 antigen is described. The XI-23 antibody reacted with all of the 89 cell suspensions carrying the HLA-A3 antigen (100% cytotoxicity) among a total of 191 suspensions tested. No extra-reactivity or cross-reactivity was observed, particularly with that of HLA-A11. This antibody can thus be considered as a good HLA-typing reagent.

Animals↗