RÉSUMÉ
This report presents our research on the conditions necessary to substain optimal in vitro prosthetic endothelialization using human endothelium cultures. Human vein endothelial cells were seeded at a concentration of 3 x 10(5)/cm2 in a gelatinized Dacron patch graft coated with a commercial collagen film, using a solution of fibrin glue. Endothelium adhesion, proliferation, and survival were measured by [3H]thymidine incorporation, after 7 days of incubation. Finally, the morphology of prosthetic endothelialization was analyzed by scanning electron microscopy. We observed that the Dacron patch grafts coated with collagen film were able to promote endothelialization better than the prostheses coated with highly concentrated collagen solution or gelatin. We therefore concluded that the collagen film that supports endothelial cell adhesion and proliferation uniformly covers the entire synthetic endoluminal surface of the Dacron graft, thus preventing endothelial cell alterations induced by direct contact with the synthetic prosthetic surface.
Sujet(s)
Adhésifs , Prothèse vasculaire , Collagène , Endothélium vasculaire/cytologie , Endothélium vasculaire/physiologie , Matrice extracellulaire , Fibrine , Téréphtalate polyéthylène , Sujet âgé , Adhérence cellulaire , Division cellulaire , Survie cellulaire , Cellules cultivées , Matériaux revêtus, biocompatibles , Humains , Veines jugulaires , Microscopie électronique à balayage , Adulte d'âge moyen , Thymidine/métabolismeRÉSUMÉ
The synergy between glycopeptides and beta-lactams was studied using different techniques such as broth macrodilution, killing curves and agar dilution combined with agar diffusion. Two glycopeptide-resistant enterococci isolated from different clinical samples were used. Results showed different effects with significant changes in MICs. Antibacterial activity was related to the concentration of glycopeptide and beta-lactam for Enterococcus faecalis 8253, while for Enterococcus faecium 8072 a paradoxical effect was observed. With this strain, the best synergic effect was detected at teicoplanin concentrations of 1-4 mg/L, but antibacterial activity was reduced at concentrations of 8, 16 and 32 mg/L. No synergic effect was observed with vancomycin. The combination of agar dilution with agar diffusion techniques may constitute a simple method for routine detection of synergic effects between glycopeptides and beta-lactams.
Sujet(s)
Antibactériens/pharmacologie , Enterococcus/effets des médicaments et des substances chimiques , Glycopeptides/pharmacologie , bêta-Lactames/pharmacologie , Céphalosporines/pharmacologie , Relation dose-effet des médicaments , Synergie des médicaments , Enterococcus faecalis/effets des médicaments et des substances chimiques , Enterococcus faecium/effets des médicaments et des substances chimiques , Imipénem/pharmacologie , Tests de sensibilité microbienne/méthodes , Pipéracilline/pharmacologie , Téicoplanine/pharmacologie , Vancomycine/pharmacologieRÉSUMÉ
Twelve monoclonal antibodies (mAbs) directed against cell-surface antigens of Myxococcus virescens cells were developed and partially characterized. All of them recognized multiple, diffuse proteic bands in Western blot and four were also reactive to living bacteria, as assessed by flow cytometry. The four latter mAbs recognized antigens common to a number of vegetative forms and spores. The selective expression of proteins recognized by mAbs on the microorganisms and the possible applications of mAbs to the study of myxobacterial cell interaction are discussed.
Sujet(s)
Anticorps monoclonaux , Antigènes bactériens , Antigènes de surface , Myxococcus/immunologie , Anticorps antibactériens , Spécificité des anticorps , Protéines bactériennes/immunologie , Microscopie immunoélectronique , Myxococcus/croissance et développement , Myxococcus/ultrastructure , Spores bactériens/immunologieRÉSUMÉ
Cells infected with HSV-1 or HSV-2 develop viral antigens which can be detected by immunofluorescence. We developed a flow cytometric indirect immunofluorescence assay to detect and quantitate antibodies to HSV-1 and HSV-2 in human sera. Results obtained by flow cytometry for detecting antibodies against HSV-1, when compared with results obtained by ELISA, showed an index of overall agreement of 100%. The correlation between the antibody titers obtained with each method was found to be highly significant. An index of overall agreement equal to 94.1% was observed between results obtained by flow cytometry and by immunofluorescence as concerns the discrimination of HSV-2 positive from negative samples. However, the correlation between antibody titers was found to be not statistically significant. The flow cytometric assay proved to be type-specific.
Sujet(s)
Anticorps antiviraux/analyse , Cytométrie en flux/méthodes , Herpèsvirus humain de type 1/immunologie , Herpèsvirus humain de type 2/immunologie , Animaux , Lignée cellulaire , Test ELISA , Technique d'immunofluorescence , Herpèsvirus humain de type 1/croissance et développement , Herpèsvirus humain de type 2/croissance et développement , Humains , Sensibilité et spécificité , Cellules VeroRÉSUMÉ
The pathologic and immunohistochemical features of 5 cases of blue nevus of the endocervix are presented: 4 of them were studied ultrastructurally. The lesions were incidentaly discovered at microscopic examination and showed pigmented dendritic cells in the cervical stroma. Immunocytochemical examination showed all cases to be positive for S-100 protein. Ultrastructurally they contained melanosomes, were surrounded by a basement membrane, and displayed occasional desmosome-like devices. Histogenesis is discussed, and support for a schwannian origin is presented.