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See detailIsolation of follicular dendritic cells from human tonsils and adenoids. II. Immunocytochemical characterization.
Heinen, Ernst ULg; Lilet, Chantal ULg; Mason, D. Y. et al

in European Journal of Immunology (1984), 14(3), 267-73

Follicular dendritic cells (FDC) are specialized cells found only within lymphoid follicles. They bind immune complexes and play a role in the presentation of antigen to follicular B cells and in the ... [more ▼]

Follicular dendritic cells (FDC) are specialized cells found only within lymphoid follicles. They bind immune complexes and play a role in the presentation of antigen to follicular B cells and in the generation of B cell memory. In the present report the isolation of FDC from human tonsils and adenoids is described. These isolated cells have an unusual spherical arrangement and enclose lymphocytes within extensions of their membranes. Their ultrastructural features are similar to those observed in situ. The reactivity of isolated FDC with a number of monoclonal antibodies was analyzed by immunofluorescence and by immunostaining (at the electron microscopic level) with colloidal gold. In keeping with the results of previous investigations on tissue sections IgM, IgG and IgA (but not IgD) can be detected on the surface of isolated FDC, as can C3b receptors and the FDC-associated antigen detected by monoclonal antibody R4/23. The immunoglobulins associated with FDC are mostly embedded in an electron-dense material. The majority of the lymphoid cells enclosed within the membrane extensions of FDC are of B cell type. These results suggest that isolated FDC may be suitable for further in vitro investigation of their role in the humoral immune response. [less ▲]

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See detailIsolation of follicular dendritic cells from human tonsils and adenoids. III. Analysis of their Fc receptors.
Heinen, Ernst ULg; Radoux, D.; Kinet-Denoel, C. et al

in Immunology (1985), 54(4), 777-84

Follicular dendritic cells (FDC), isolated from human tonsils or adenoids, were tested for their capacity to retain monomeric, aggregated or antigen-bound human antibodies in the absence of serum. FDC ... [more ▼]

Follicular dendritic cells (FDC), isolated from human tonsils or adenoids, were tested for their capacity to retain monomeric, aggregated or antigen-bound human antibodies in the absence of serum. FDC retain fluorescein-labelled heat-aggregated human immunoglobulins, but not monomeric ones nor fluorescein-labelled F(ab')2 in monomeric or aggregated form. Ultrastructural observations showed that colloidal gold-labelled monomeric, or antigen-bound, antibodies directed against tetanus toxoid are retained by dendrites and membrane infoldings of FDC but are never located in cytoplasmic vesicles. This retention was inhibited by incubating FDC with unlabelled aggregated or antigen-bound antibodies. When gold-labelled anti-tetanus toxoid antibodies were incubated in the presence of protein-A before the contact with FDC, a strong reduction of their retention occurred. This further suggested the presence of Fc receptors on isolated tonsillar FDC. Endocytosis was not observed in isolated FDC, even after prolonged incubation in presence of labelled immune complexes: their Fc receptors are, thus, not related to a phagocytic activity as they are in macrophages. Simultaneous ultrastructural labelling of Fc and C3b receptors with colloidal gold particles of different sizes did not reveal any clear relations between these two receptors on the surface of FDC. [less ▲]

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See detailIsolation of follicular dendritic cells from human tonsils and adenoids. In vitro culture.
Cormann, N.; Heinen, Ernst ULg; Kinet-Denoel, C. et al

in Advances in Experimental Medicine and Biology (1988), 237

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See detailIsolation of follicular dendritic cells from human tonsils and adenoids. V. Effect on lymphocyte proliferation and differentiation.
Cormann, N.; Lesage, F.; Heinen, Ernst ULg et al

in Immunology Letters (1986), 14(1), 29-35

Follicular dendritic cells (FDC) are located only in lymph follicles and are characterized by their capacity to retain high amounts of immune complexes on their plasma membranes. As their functions in ... [more ▼]

Follicular dendritic cells (FDC) are located only in lymph follicles and are characterized by their capacity to retain high amounts of immune complexes on their plasma membranes. As their functions in germinal centres are unknown, we isolated them from human tonsils and cultured them with autologous lymphoid cells. Cultures of lymphoid cells alone or with added macrophages were used as controls. Lymphoid cells incorporated tritiated thymidine only when FDC and lectins were added; this could be shown after several periods of time. However, the Ig secretion by lymphoid cell populations was inhibited by FDC after several days in vitro. In contrast, the supernatants of lymphocytes cultured alone or with macrophages only for the same periods of time contained increasing amounts of immunoglobulins. This inhibitory effect of FDC on immunoglobulin production was observed for all considered isotypes. Our data suggest that FDC stimulate lymphoid cell proliferation but reduce B-cell differentiation. This is the first accessory cell activity definitely shown for FDC in cultures. [less ▲]

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See detailIsolation of follicular dendritic cells from human tonsils and adenoids. VI. Analysis of prostaglandin secretion.
Heinen, Ernst ULg; Cormann, N.; Braun, M. et al

in Annales de l'Institut Pasteur. Immunologie (1986), 137D(3), 369-82

Follicular dendritic cells (FDC) are able to fix high amounts of immune complexes by C3b or Fc receptors without endocytosis and for long periods of time. In order to determine the function of this ... [more ▼]

Follicular dendritic cells (FDC) are able to fix high amounts of immune complexes by C3b or Fc receptors without endocytosis and for long periods of time. In order to determine the function of this retention, we analysed the secretion of prostaglandin E2 (PGE2) by FDC in vitro; indeed, it is well-known that immune complex fixation on cells may induce PGE2 production. FDC were isolated by enzymic digestion of lymph follicles dissected under the biomicroscope from human tonsils or adenoids. Isolated FDC appeared as spherical clusters where they enveloped lymphoid cells with their cytoplasmic extensions. Tests were performed in synthetic culture media or in media supplemented with foetal calf serum. PGE2 production in FDC suspensions was compared to that of lymphocyte or macrophage-enriched populations prepared from the same human tonsils. In all experimental conditions, FDC and macrophage-enriched cell populations produced high levels of PGE2, inversely to lymphoid cell populations. This secretion was inhibited by indomethacin. At the ultrastructural level, we also showed that 3H-arachidonic acid was metabolized in cell membranes of all three cell types. The PGE2 produced in the culture media, according to our experimental conditions, do not influence cell proliferation, as assessed by 3H-thymidine incorporation tests on phytohaemagglutinin-stimulated lymphocytes. [less ▲]

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See detailIsolation Of Highly Performant Sulfate Reducers From Sulfate-Rich Environments
Hiligsmann, Serge ULg; Jacques, Philippe; Thonart, Philippe ULg

in Biodegradation (1998), 9(3-4), 285-292

Eleven pure strains of sulfate-reducing bacteria have been isolated from lab-scale bioreactors or disposal sites, all featuring relatively high concentrations of sulfate, and from natural environments in ... [more ▼]

Eleven pure strains of sulfate-reducing bacteria have been isolated from lab-scale bioreactors or disposal sites, all featuring relatively high concentrations of sulfate, and from natural environments in order to produce sulfide from gypsum using hydrogen as energy source. The properties of the eleven strains have been investigated and compared to these of three collection strains i.e. Desulfovibrio desulfuricans and vulgaris and Desulfotomaculum orientis. Particular attention was paid to the absolute and relative sulfide production rate and to the hydrogen sulfide inhibition level. By comparison to the collection strains, a 75 % higher production rate and a hydrogen sulfide inhibition level about twice higher i.e. 25.1 mM have been achieved with strains isolated from sulfate-rich environments. The strain selection, particularly from sulfate-rich environments, should be considered as an optimization factor for the sulfate reduction processes. [less ▲]

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See detailIsolation of insecticidal proteins within the pea seeds (Pisum sativum L.)
Cuartero Diaz, Gaëtan; Francis, Frédéric ULg; Portetelle, Daniel ULg et al

Poster (2006, October)

Consequently with the pressure exerted by chemical pesticides on environment, and the awakening of politics, the demand for bio-pesticides is increasing. Nevertheless, supply is not sufficient, and ... [more ▼]

Consequently with the pressure exerted by chemical pesticides on environment, and the awakening of politics, the demand for bio-pesticides is increasing. Nevertheless, supply is not sufficient, and moreover those products are not competing enough. In this context, the aim of this research is to set up a biological insecticide, which is economic, with vegetal proteins resulting from alimentary industry, here the pea, Pisum sativum L.. A group of proteins, which is quite easy to highlight, is present in relatively important proportions (2%) in pea seeds, it’s the lectins class. Insecticidal effects of lectins from different organisms have already been proved. Indeed, by binding to membrane glycosyl groups of digestive tract cells, lectins can be very toxic for a lot of insects. Thus initially we focus our investigations on Pisum sativum lectins (PSL). First, PSL have been localised within the industrial process among different extraction juices. Then, a chromatography has been performed on the selected juice with FPLC technology. Although the matrix used for this chromatography, sephadex G75, is a banal bed for gel filtration, it is in this case a real combination between classical gel filtration and affinity chromatography. Indeed due the particular properties of lectins, they fixed carbonyl group of the bed and have to be eluted after the filtration part with a solution of glucose. Then the collected fractions corresponding to UV-peaks on the chromatogram were separated by electrophoresis 2D and identified by mass spectrometry (ESI MS/MS) coupled with data bank investigations. Secondly bioassays using artificial diets have been developed on Myzus persicae in the aim to study the aphicid effects of theses fractions with rm and LC50.These estimators show significant mortality rates but also change in the fecundity and in the development of nymph. [less ▲]

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See detailIsolation of Mycoplasma species from the lower respiratory tract of healthy cattle and cattle with respiratory disease in Belgium
Thomas, Anne; Ball, H.; Dizier, Isabelle ULg et al

in Veterinary Record (2002), 151(16), 472-476

Between 1997 and 2000, a total of 150 healthy cattle and 238 animals with respiratory disease were examined for six Mycoplasma species. Attempts were made to detect Mycoplasma canis, Mycoplasma dispar and ... [more ▼]

Between 1997 and 2000, a total of 150 healthy cattle and 238 animals with respiratory disease were examined for six Mycoplasma species. Attempts were made to detect Mycoplasma canis, Mycoplasma dispar and Ureaplasma diversum in calves with recurrent disease, and all three of these species were identified in calves with recurrent disease and in healthy lungs. In healthy calves, 84 per cent of bronchoalveolar lavage fluids were mycoplasma free; when cultures were positive, Mycoplasma bovirhinis was the only species isolated. Mycoplasmas were isolated from 78 per cent of animals suffering recurrent respiratory disease and from 65 per cent of acute respiratory cases. Mycoplasma bovis was isolated from bronchoalveolar lavages from 35 per cent of calves suffering recurrent respiratory disease, and from 50 per cent of acute cases, and from 20 per cent of pneumonic cases examined postmortem. M bovis was associated with other Mycoplasma species in 44 per cent of cases. M dispar was also isolated from 45.5 per cent of calves suffering recurrent respiratory disease, often in association with M bovis. M canis was identified for the first time in diseased Belgian cattle. Other mycoplasmas, including Mycoplasma arginini, Mycoplasma alkalescens and U diversum, were isolated less frequently. Associations between mycoplasmas and other pathogens were often observed. Among lungs infected with Pasteurella and/or Mannheimia species, more than 50 per cent were mixed infections with M bovis. [less ▲]

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See detailIsolation of new metabolites from Pseudomonas putida involved in plant resistance induction
Ongena, Marc ULg; Budzikiewicz, H.; Jacques, Ph. et al

Poster (2001, September)

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See detailIsolation of new pregnancy-associated glycoproteins from water buffalo (Bubalus bubalis) placenta by Vicia villosa affinity chromatography.
Barbato, O.; Melo de Sousa, Noelita ULg; Klisch, K. et al

in Research in Veterinary Science (2008), 85(3), 457-66

The present study describes the isolation and characterization of new pregnancy-associated glycoprotein molecules (PAG) from midpregnancy and late-pregnancy placentas in the water buffalo (Bubalus bubalis ... [more ▼]

The present study describes the isolation and characterization of new pregnancy-associated glycoprotein molecules (PAG) from midpregnancy and late-pregnancy placentas in the water buffalo (Bubalus bubalis). After extraction, the homogenates are subjected to acid and ammonium sulfate precipitations followed by DEAE chromatography. Subsequently, the water buffalo PAG (wbPAG) from these solutions are enriched by Vicia villosa agarose (VVA) affinity chromatography. As determined by western blotting with anti-PAG sera, the apparent molecular masses of the immunoreactive bands from the VVA peaks range from 59.5 to 75.8kDa and from 57.8 to 73.3kDa in the midpregnancy and late-pregnancy placentas, respectively. Amino-terminal microsequencing of the immunoreactive proteins has allowed the identification of three distinct wbPAG sequences, which have been deposited in the SwissProt database: RGSXLTIHPLRNIRDFFYVG (acc. no. P85048), RGSXLTILPLRNIID (acc. no. P85049), and RGSXLTHLPLRNI (acc. no. P85050). Their comparison to previously identified proteins has shown that two of them are new because they have not been described before. Our results confirm the suitability of VVA chromatography for the enrichment of the multiple PAG molecules expressed in buffalo placenta. [less ▲]

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See detailIsolation of novel hydrolytic genes from an Antarctic metagenomic library
Pipers, D.; Berlemont, R.; Power, P. et al

Poster (2008)

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See detailIsolation of Nucleoli from Ehrlich Ascites Tumor Cells and Dynamics of Nascent RNA within Isolated Nucleoli.
Thiry, Marc ULg; Ploton, Dominique

in Methods in Molecular Biology (Clifton, N.J.) (2008), 463

Here we describe a new, rapid method for isolating nucleoli from Ehrlich tumor cells that preserves their morphological integrity and high transcriptional activity. Until now, methods for isolation of ... [more ▼]

Here we describe a new, rapid method for isolating nucleoli from Ehrlich tumor cells that preserves their morphological integrity and high transcriptional activity. Until now, methods for isolation of nucleoli were generally assumed to empty one of their three main compartments, the fibrillar center, of its contents. This new method consists of sonicating cells in an isotonic medium containing MgSO(4), spermidine, and spermine, followed by separation of nucleoli through a Percoll density gradient. Using the nonisotopic approach of labelling with BrUTP, we have further investigated the dynamics of nascent ribosomal RNAs (rRNAs) within morphologically intact isolated nucleoli at the electron microscope level. We show that ribosomal transcripts are elongated in the cortex of the fibrillar center and then enter the surrounding dense fibrillar component. [less ▲]

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See detailIsolation of nucleoli from ELT cells: a quick new method that preserves morphological integrity and high transcriptional activity.
Vandelaer, M.; Thiry, Marc ULg; Goessens, Guy ULg

in Experimental Cell Research (1996), 228(1), 125-31

We have developed a quick new method for isolating nucleoli which, unlike the methods in current use, preserves the nucleolar ultrastructure. Until now, the isolation process has generally been assumed to ... [more ▼]

We have developed a quick new method for isolating nucleoli which, unlike the methods in current use, preserves the nucleolar ultrastructure. Until now, the isolation process has generally been assumed to empty one of the three major compartments of the nucleolus, the fibrillar center, of its content. We have used the AgNOR staining and in vitro transcription assay to test the degree of structural and functional preservation of the isolated nucleoli. Our results demonstrate the value of our procedure as a reliable tool for biochemical and ultrastructural studies on the nucleolus. Moreover, these proprieties prompt us to investigate the rRNA synthesis, using a nonisotopic approach, within morphologically intact isolated nucleoli. Thus, we show that newly synthesized rRNA transcripts are located not only in the dense fibrillar component, but also indubitably in the fibrillar center. [less ▲]

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See detailIsolation of O157 : H7 and other enterohaemorrhagic Escherichia coli from foodstuffs.
Daube, Georges ULg; Chahed, Amina

in Factors affecting the microbial quality of meat, 4. Microbial methods for the meat industry. Concerted Action CT94-1456 (1997)

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See detailIsolation of PAG from buffalo (Bubalus bubalis) placenta
Barbato, O.; Melo de Sousa, Noelita ULg; Klisch, K. et al

in Reproduction (Cambridge, England). Abstract Series (2006), Suppl

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See detailIsolation of plunc (palate, lung and nasal epithelium clone protein) in the bronchoalveolar lavage from dogs: preliminary results
Clercx, A.; Vandenbussche, G.; Ruysschaert, J. M. et al

in 13th ESVIM Meeting - Uppsala - Septembre 2003 (2003, September)

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See detailIsolation of pregnancy-associated glycoproteins of the American bison (Bison bison) at first half of pregnancy
Kiewisz, J.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

in General and Comparative Endocrinology (2008), 155(1), 164-175

This paper describes the successful purification and characterisation of pregnancy-associated glycoproteins (PAG) extracted from placenta (3-4 months) of American bisons (Amb). Chorionic AmbPAG proteins ... [more ▼]

This paper describes the successful purification and characterisation of pregnancy-associated glycoproteins (PAG) extracted from placenta (3-4 months) of American bisons (Amb). Chorionic AmbPAG proteins were purified from foetal cotyledonary tissues (CT) and liquid cotyledonary-carrying proteins (LCP) leaking from damaged cells. Our protocols successfully indicated the usefulness of AmbPAG protein identification, especially from LCP fraction. The AmbPAGs were extracted, precipitated and eluted during DEAE cellulose chromatography. The richest protein fractions were further chromatographed on VVA (Vicia villosa agglutinin affinity column), then characterised by mono- and bi-dimensional electrophoresis, Western blot and N-terminal amino acid (aa) sequence. After being transferred to PVDF membranes, three selected VVA-purified AmbPAG isoforms differing in molecular masses and isoelectric points (Ip 4-4.6) were selected for sequencing. One identified N-terminal 25 aa sequence of AmbPAG72 kDa CT form was identified as completely new (RGSNI_TSLPLQNVIDLFYVGNITIG). Two other AmbPAG proteins purified from different sources (74 kDa CT and 76 kDa LCP forms; RGSNLTIHPLRNIRDIFYVGNITIG) were identical or corresponded to N-terminus of various bovine PAGs (boPAG). The two AmbPAGs (74 kDa CT and 76 kDa LCP) revealed identical micro-sequence to boPAG7; and were similar mainly to bovine PAG4, -6, -15 and -17 precursors that were identified by full-length sequencing derived from cDNA cloning. The novel sequence of the AmbPAG (72 kDa CT) was related to some boPAG and various other ruminant PAG precursors (caprine and ovine). All three identified AmbPAG sequences were also relatively similar to mature forms of purified native boPAG56-75kDa proteins. This is the first report indicating aa sequences of native AmbPAG proteins purified from placenta (CT and LCP) of bison species. The N-terminal sequences of the AmbPAGs have been deposited in the EMBL-EBI database (UniProtKB; Accession Nos.: P84916, P84917 and P84918). (C) 2007 Elsevier Inc. All rights reserved. [less ▲]

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See detailIsolation of shiga toxin-producing Escherichia coli from a South American camelid (Lama guanicoe) with diarrhea.
Mercado, E. C.; Rodriguez, Sabrina ULg; Elizondo, A. M. et al

in Journal of Clinical Microbiology (2004), 42(10), 4809-11

Shiga toxin-producing Escherichia coli belonging to serotype O26:H11 was isolated from a 2-month-old guanaco with severe watery diarrhea. E. coli colonies carried the stx1 and eae genes, showed localized ... [more ▼]

Shiga toxin-producing Escherichia coli belonging to serotype O26:H11 was isolated from a 2-month-old guanaco with severe watery diarrhea. E. coli colonies carried the stx1 and eae genes, showed localized adherence to HEp-2 cells, and produced enterohemolysin. A serological response to lipopolysaccharide O26 was observed at the onset of diarrhea. [less ▲]

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