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Biomedical subjects

D Rigal

Publications and source records attributed to D Rigal.

At least 91 records · Page 5Linked to original sources
PubMed1991

Expression, function and regulation of the intercellular adhesion molecule-1 (ICAM-1) on human intestinal epithelial cell lines.

We have characterized the presence of the intercellular adhesion molecule-1 (ICAM-1) (CD54) on human intestinal adenocarcinoma cell lines as a nonreducible polypeptide of Mr 93 kDa, identified as a rhinovirus receptor. Expression of ICAM-1 was positively correlated with enterocytic maturation, in that the percentage of ICAM-1+ cells was highest in the most differentiated cell line Caco-2. ICAM-1 could be up-regulated only on the less differentiated cell lines HT29 and T84 by phorbol 12-myristate 13-acetate and by the cytokines interferon-gamma (IFN-gamma) and interleukin (IL) 1 beta. Enterocyte ICAM-1 was involved in adhesion to activated T cells through binding to the leukocyte function associated antigen-1 (LFA-1). These data provide evidence that colon adenocarcinoma cell lines express functional ICAM-1 sensitive to cytokine regulation. These findings support the hypothesis that lympho-epithelial interactions involving the ICAM-1/LFA-1 pathway may be implicated in immunosurveillance of colon adenocarcinomas, inflammatory bowel disease and celiac disease, where increased levels of proinflammatory cytokines are locally produced within the gut mucosa.

Antigens, CD↗
PubMed1991

Haemolytic disease of the newborn infant. Long term efficiency of the screening and the prevention of alloimmunization in the mother: thirty years of experience.

During the last thirty years, the diagnosis, management and prevention of haemolytic disease of the newborn infant (HDN) have improved. From 1959 to 1988, 3004 HDN (ABO excluded) have been collected. The percentage of HDN with anti-D alloimmunization decreased significantly (98.4% from 1959 to 1968, 93.5% from 1969 to 1978 and 68.1% from 1979 to 1988). The anti-D HDN with exchange transfusion (ET) fell significantly between the first and second periods (577 versus 970; chi 2 = 19.92; P less than 0.001). On the other hand, the number of HDN other than anti-D increased during these three periods, but the percentage of these HDN which needed ET decreased. Our study shows the long term efficiency of the prevention of anti-D alloimmunization (since 1970) and of the irregular antibodies screening among all pregnant women (since 1979).

Antibodies, Anti-Idiotypic↗
PubMed1991

Dextran sulfate specifically interacts with the human LFA-1 molecule (leucocyte function associated antigen-1).

We have investigated by flow cytometry the action of dextran sulfate (DxS) on the expression of the LFA-1 molecule in human lymphocytes. This work was undertaken because of the involvement of the LFA-1 molecule in HIV-1 induced syncytia and because of the role of DxS played in the inhibition of syncytia formation. Firstly we detected five distinct topographic regions (epitopes) on the LFA-1 molecule with a panel of 11 monoclonal antibodies (Mabs). Then we demonstrated that DxS interacts with some epitopes mainly present on the alpha chain of the LFA-1 molecule. This inhibition on the LFA-1 expressions by DxS occurs after 1-3 hr of incubation of either 4 or 37 degrees C with complete reappearance of LFA-1 within 1 hr of placing cells in fresh medium. In addition both 5 and 500 kDa have been found to have a similar influence on the inhibition of the LFA-1 expression, while non sulfated dextran have no effect. Other sulfated polyanion (SP) such as heparin and chondroitin sulfate have no effect on the LFA-1 expression. Further at 4 degrees C, DxS does not alter the expression of molecules recognized by Mab such as Leu3a (CD4), Leu2a (CD8), Leu4 (CD3) and Leu5b (CD2). However at 4 degrees C, DxS decreases the expression of CD45R molecule which is recognized by Mab Gap8.3. At 37 degrees C, we observe a decrease also in CD4 expression after DxS exposure. It has also been found that DxS decreases LFA-1 expression to the same extent regardless of the basal expression of LFA-1 in each selected cell subset (LFA-1 low, dim or bright). These results suggest that the inhibitory effect of DxS on the HIV-induced syncytium formation could be due partially to a specific steric hindrance of some LFA-1 determinants.

Antibodies, Monoclonal↗
PubMed1991

Functional epitope analysis of the human CD11a/CD18 molecule (LFA-1, lymphocyte function-associated antigen 1) involved in HIV-1-induced syncytium formation.

After binding to the CD4 receptor, the human immunodeficiency virus 1 (HIV-1) may enter the T cell and induce the formation of multinucleated giant cells (syncytia). As well as the CD4 molecule, other molecules, such as the lymphocyte function-associated antigen 1 (LFA-1, CD11a/CD18) have been shown to be involved in HIV-1-mediated cell fusion. This study was designed to define regions on the human CD11a/CD18 molecule important for the HIV-1-induced syncytium formation. A CD11a/CD18 MoAb panel discriminating at least five distinct and spatially distant domains on the LFA-1 molecule was used. Comparison of the functional activity of different MoAbs demonstrated that all epitopes of the LFA-1 molecule were not of equal importance in HIV-1-induced syncytium formation between H9.III cells chronically infected with HIV-1 and uninfected CD4+ SupT1 cells. We also demonstrated that CD11a/CD18 MoAbs inhibit syncytia formation only at the level of the uninfected SupT1 cells, suggesting that the LFA-1 molecule expressed on SupT1 cells interacts with ligand(s) expressed on the infected H9.III cells. Two potential LFA-1 receptors on the H9.III cells were tested: the ICAM-1 molecule (intercellular adhesion molecule 1, CD54) and the HIV-1 transmembrane glycoprotein 41 (gp41). A CD54 MoAb (84H10) partially inhibited syncytia formation, thus demonstrating the involvement of the ICAM-1 molecule in the HIV-1-mediated cell fusion. However, the CD11a/CD18 MoAbs do not inhibit binding of the viral envelope glycoprotein gp41 to the cell surface, irrespective of the MoAb concentration used. Although we have not been successful in identifying all candidate fusion receptors for the LFA-1 molecule, these data suggest that some LFA-1 regions are important for syncytium formation and, therefore, in the cell-to-cell transmission of virus and in the spread of infection.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Regulation and functional involvement of distinct determinants of leucocyte function-associated antigen 1 (LFA-1) in T-cell activation in vitro.

The expression of leucocyte function-associated antigen 1 (LFA-1) was studied by immunofluorescence method on human peripheral blood mononuclear cells (PBMC) stimulated by the phytohaemagglutinin lectin (PHA). Monoclonal antibodies (MoAb) Mas 191c, IOT18 (directed against the beta-chain, 95 kDa, CD18) and IOT16, SPVL7, MHM24 (identificating the alpha-chain, 180 kDa, CD11a) were used, defining the 'CD11a/CD18' antibody panel. By means of cross-linking or competitive experiments, we showed that these antibodies recognized at least four distinct and spatially distant domains on the LFA-1 molecule. Immunofluorescence analysis revealed that the up-regulation of LFA-1 expression was a late event, similar to the expression kinetics of the HLA DR and CD38 molecules, and followed the appearance of CD25 and CD71 molecules. Moreover, it was established that the LFA-1 up-regulation required mRNA and protein synthesis. Functional activity comparison of the different anti LFA-1 MoAb showed that the CD11a MoAb significantly inhibited the proliferation of lymphocytes stimulated by the phytohaemagglutinin to various extents, as the LFA-1 alpha determinant identified. By contrast, the CD18 MoAb did not influence strongly this cell process. We observed only a dim inhibitory effect with the CD18 MoAb recognizing an epitope common or very close to an LFA-1 alpha determinant. These results suggested that the LFA-1 antigen was important, at a molecular level, in the regulation of T-cell activation.

Antigens, Differentiation↗
PubMed1991

[Treatment of dry eye syndrome with lacrimal gel: a randomized multicenter study].

The appearance on the French market of a carbomer tear substitute, Gel-Larmes, an original galenic form, constitutes a real therapeutic progress in the treatment of dry eye syndrome. An open randomized multicentric trial was conducted comparing the tolerance and efficacy of Gel-Larmes with those of eye drops containing chondroitin sulphate. The statistical analysis evidences an inferior average number of daily instillations for Gel-Larmes, its better efficacy on the symptoms as well as on the objective criteria: biomicroscopic examination, break-up time, rose Bengal test. The tolerance of the product is excellent and 81% of the patients express their wish to pursue Gel-Larmes versus 54% for the reference product.

Acrylic Resins↗
PubMed1991

[Fluorophotometry and corneal endothelium].

The corneal endothelium plays a major part in corneal deturgence and hydratation by functioning as a barrier and a pump. Fluorophotometry enables assessment of this barrier function because of endothelial permeability to fluorescein. After a description of the technique of fluorophotometry, the authors show its interest in the understanding of endothelial physiopathology: during aging, in compensated or decompensated endothelial dystrophy, during lens and corneal surgery, in irido-corneal endothelial syndrome and in pharmacology.

Biological Transport↗
PubMed1991

Proliferation and activation of human mononuclear cells induced by ionomycin in a serum-free medium.

Ionomycin was capable of inducing the proliferation and activation of human peripheral blood mononuclear cells (MNC) in serum-free culture medium. Optimal responses, evaluated by tritiated thymidine ([3H]Thy) incorporation and by HLA-DR antigen expression, were obtained with 0.5 micrograms/ml ionomycin in 72-hour cultures. The two ionomycin-induced effects required the presence of monocytes from the start of the culture. It was observed that no cell adhered to the support after three days of culture in the presence of ionomycin, when compared with an ionomycin-free control. The cells stimulated with ionomycin had a large cytoplasm, were metabolically highly active and had a morphology comparable to that of PHA-stimulated cells. At the end of culture, 23 +/- 4% of cells were DR+; this percentage was only partially found (15 +/- 3%) in all the cell populations studied (T and B lymphocytes, NK cells, monocytes). This led us to believe that this expression occurred in other, probably non-differentiated cells. These later were not stimulated to mature by ionomycin. Thus, ionomycin constitutes an essential early signal, but is insufficient to trigger the complete maturation of cells.

Cell Division↗
PubMed1990

Phenotypic analysis of a large number of normal human bone marrow sample by flow cytometry.

Bone marrow aspirates from 48 healthy donors (34 adults, 14 children) were analyzed by flow cytometry (FACS Analyzer) after purification of low-density bone marrow cells (Ld BMC) on a density gradient (d = 1,077) and labelling with 23 anti-hematopoietic cell monoclonal antibodies. Based on physical properties, these Ld BMC could be divided into four different populations called E, My, Mo and L, which comprised 14% +/- 9%, 31% +/- 16%, 10% +/- 5% and 45% +/- 14% of these cells, respectively. The phenotypic analysis of these different populations enabled the identification in E, of erythrocytes (Glycophorin A+, Rhesus D+, but negative for early erythroid differentiation markers such as the transferrin receptor (Tf. R) and the FA6-152 antigen); in My of cells of the myeloid lineage (VIM2+, HLA DR-); in Mo of cells of the monocytic lineage (VIM2+, CD14+) plus some myeloblasts (VIM2+, CD14-, HLADR+) and finally in L of a heterogeneous population including: 1. T lymphocytes labelled to the same extent by CD2, CD3, CD5 and CD6 (28% +/- 10%), B lymphocytes assessed by CD19 and CD20 (12% +/- 8%), Pre-B cells (CD10+ = 8% +/- 7%), less than 5% of "natural killer" cells (CD16+ or Leu7+) and finally, less than 6% of myelomonocytes (CD14+ and/or VIM2+). 2. The erythroid lineage (rhesus D+ = 42% +/- 20%, Tf.R+ and FA6-152+ = 32% +/- 12%). 3. Undifferentiated cells or progenitor cells (CD34+ = 7% +/- 5%). 4. Cells unlabelled by any antibodies (approximately 6%). We observed no difference between bone marrow samples from adults or children, with respect to physical properties, and with all but four immunological markers. A significantly higher proportion of B cells (CD19+ and CD10+) (P less than 0.001) and undifferentiated cells (CD34+ and HLADR+) (P less than 0.02) was observed in children. These data, obtained from a large number of bone marrow samples, could be used to quantify the imbalance of some bone marrow disorders.

Adolescent↗
PubMed1990

Systemic lupus erythematosus in dogs: association to the major histocompatibility complex class I antigen DLA-A7.

The DLA-A,B antigens and the allotypes of the fourth complement component have been determined in German shepherd dogs suffering from systemic lupus erythematosus. We have typed 26 unrelated affected dogs, 11 animals of a three generation family, and 16 dogs of a colony with a high frequency of the disease. The results obtained from the 26 unrelated diseased dogs were compared to those determined in the 23 unaffected German shepherds. The antigen DLA-A7 was found to be predominant in the diseased group with a c2 = 11.02, Pc = 0.02, and a relative risk for the carriers of 11.93. The antigens DLA-A1 and DLA-B5 were negatively associated to the disease (c2 = 14.95, Pc = 0.001, and c2 = 17.16, P = 0.0008 respectively) and thus may be of protective nature. These data were further substantiated by the typing of the three generation family and the colony.

Animals↗
PubMed1990

Leukocyte function-associated antigen-1 expression on peripheral blood mononuclear cell subsets in HIV-1 seropositive patients.

In order to further investigate immune dysfunctions in HIV-1 infection, we studied the intensity of leukocyte function-associated antigen-1 (LFA-1) expression using a novel application of immunofluorescence analysis in 14 adults and 5 children seropositive for HIV-1 and in 14 healthy adults and 5 healthy children seronegative for HIV-1. While almost all lymphocytes in human peripheral blood expressed LFA-1 and while the percentage of the LFA-1 positive cells was not modified during the course of the HIV-1 infection in both adults and children, our results showed an increase of the LFA-1 expression on selected peripheral blood mononuclear cell subsets. Some LFA-1-labeled functional peripheral blood mononuclear cell subsets such as the CD16, CD14, CD3, and CD8 lymphocyte subpopulations expressed higher levels of the LFA-1 molecule during the HIV-1 infection. The LFA-1 dim cell subsets (CD4 cells) and the LFA-1 low cell subpopulation (CD19 lymphocytes) were not affected by the HIV-1 infection. Moreover, in the CD8 and CD3 cell subsets displaying a heterogeneous LFA-1 expression (dim and bright), we also observed a decrease of the LFA-1 dim/LFA-1 bright cell ratio.

Antibodies, Monoclonal↗
PubMed1990

The gel test: a new way to detect red cell antigen-antibody reactions.

A new process for the detection of red cell (RBC) antigen antibody reactions is described. It is applicable to most of the tests performed in blood group serology. The procedures are standardized and easy, and they provide clear and stable reactions that improve the interpretation of results. The process uses special microtubes filled with a mixture of gel, buffer, and reagent. Depending on the test to be carried out, the test uses a neutral gel containing no reagents (reagents are added to top of gel) or a specific gel containing reagents (e.g., antiglobulin serum or anti-A, -B, -D, etc.). A suspension of RBCs (for typing or the direct antiglobulin test) or a mixture of RBCs and serum (for reverse ABO typing or antibody characterization) is centrifuged through the gel under precise conditions. In negative reactions, the RBCs pass through the gel and pellet in the bottom of the tube, whereas, in positive reactions, they are trapped in the gel and the reaction may be read for hours afterwards. The test is easy to perform, sensitive, and reproducible. The antiglobulin tests can be performed without washing of the RBCs. There should be a reduction of risk from biohazardous materials.

Antibodies↗
PubMed1990

Important variations of maternal anti-Rhesus (D) antibody level during two consecutive pregnancies without antigenic stimulus.

In many cases, during pregnancies of anti-D alloimmunized women, without antigenic stimulus, the anti-D concentration remains stable. We report here a case of a woman anti-D and anti-C alloimmunized which has presented high variation of anti-D concentration in her serum during two successive pregnancies with a Rh-negative fetus. Thus, the Liley Index only has confirmed the absence of fetal damage.

Adult↗
PubMed1990

Long-term culture of human bone marrow. I. characterization of adherent cells in flow cytometry.

Using long-term culture techniques, we were able to characterize the different adherent cell elements of the in vitro bone marrow microenvironment by flow cytometry. After 2 weeks of culture, four adherent cell subsets, L, MM, F, and M, were distinguished according to their intrinsic cellular characteristics of volume and spontaneous fluorescence. Using four immunological markers, we identified each population as a hematopoietic lymphocytic group (L), CD45+, VIM2-, CD14-; a hematopoietic myelomonocytic group (MM), CD45+, VIM2+, CD14-; a hematopoietic macrophage group (M), brightly autofluorescent, CD45+, VIM2-, CD14+; and a group of fibroblastoid cells (F) with a very high volume, CD45-, VIM2-, CD14-, and collagen III+. Isolation of the different hematopoietic and nonhematopoietic components of long-term bone marrow culture is thus possible using flow cytometry analysis according to the cell characteristic of volume and spontaneous fluorescence alone.

Antigens, CD↗
PubMed1990

[Omenn syndrome].

Omenn's syndrome is a rare autosomal recessive disease characterized by the onset, from the first weeks of life, of an exsudative skin rash, alopecia, hepatosplenomegaly, diffuse lymph-nodes, diarrhea and increased susceptibility to infections with hypereosinophilia. The associated severe combined immunodeficiency (SCID) differs from the other SCID by the existence of lymphocytosis. The number of T lymphocytes is normal or elevated; they are sometimes immature; the distribution of their subsets (CD4/CD8) is variable. The B lymphocytes are quantitatively and functionally deficient. Pathological investigations reveal major lymphoid depletion with severe thymic hypoplasia associated with a proliferation of cells which have the whole immunohistochemical characteristics of Langerhans' cells but do not contain their specific granulations (Birbeck's granulations) on the ultrastructural examination. These cells are also found in the skin, lungs and liver. The outcome is usually fatal before 1 year of age. The pathogenesis of this disease is still discussed: it might be the result, in an immunodeficient child, either of a graft-versus-host reaction after materno-fetal transfusion of immunocompetent cells, or of an abnormal immunologic reaction after antigenic stimulation, or a deficit of molecules in lymphocyte ecotaxy.

Eosinophilia↗
PubMed1990

[Spontaneous fluctuation of extracellular matrix molecules on the surface of human skin fibroblasts in culture: flow cytometric analysis].

The evolution of five surface markers (CD 10, fibronectin, collagens I, III, IV) was analysed in cytofluorometry after immunolabelling of cultured human skin fibroblasts. The expression of the CD10 molecule and collagen IV remained stable. On the contrary, there was a spontaneous variation of the cell surface distribution of fibronectin and collagens I and III. This variation was periodical and followed the subculture rhythm. After every passage, the density of matrix components increased at the cell surface. The maximum of the density was achieved on confluent fibroblasts then decreased until the next passage. The fibronectin and collagens I and III expression was permanently altered on senescent fibroblasts. Modifications of the expression of extracellular matrix proteins on the fibroblasts surface were closely linked with cellular density and senescence.

Cells, Cultured↗