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See detailNucleation phenomenon in silica xerogels and Pd/SiO2, Ag/SiO2, Cu/SiO2 cogelled catalysts
Alié, Christelle ULg; Lambert, Stéphanie ULg; Heinrichs, Benoît ULg et al

in Journal of Sol-Gel Science and Technology (2003), 26(1-3), 827-830

Pd/SiO2, Ag/SiO2 and Cu/SiO2 xerogel catalysts have been synthesized by cogelation of tetraethoxysilane (TEOS) and chelates of Pd, Ag and Cu with 3-(2-aminoethylamino) propyltrimethoxysilane (EDAS). It ... [more ▼]

Pd/SiO2, Ag/SiO2 and Cu/SiO2 xerogel catalysts have been synthesized by cogelation of tetraethoxysilane (TEOS) and chelates of Pd, Ag and Cu with 3-(2-aminoethylamino) propyltrimethoxysilane (EDAS). It appears that, in cogelled samples, the metal complex acts as a nucleation agent in the formation of silica particles. The resulting catalysts are then composed of completely accessible metallic crystallites with a diameter of about 3 nm located inside silica porous particles with a monodisperse microporous distribution. Xerogels without metal synthesized with EDAS and TEOS (C. Alie, R. Pirard, A. J. Lecloux, and J.-P. Pirard, J. Non-Cryst. Solids 289, 88 (2001)) verify this hypothesis of nucleation by EDAS. [less ▲]

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See detailNucleic acid compartmentalization within the cell nucleus by in situ transferase-immunogold techniques.
Thiry, Marc ULg

in Microscopy Research and Technique (1995), 31(1), 4-21

In the present review, we report on recent results obtained by in situ transferase-immunogold techniques as to the ultrastructural distribution of DNA and RNA within the cell nucleus. Special emphasis is ... [more ▼]

In the present review, we report on recent results obtained by in situ transferase-immunogold techniques as to the ultrastructural distribution of DNA and RNA within the cell nucleus. Special emphasis is placed on the various nucleolar components and the various enigmatic structures of the extranucleolar region: interchromatin granules, coiled bodies, and simple nuclear bodies. These data are discussed in the light of our current understanding of the functional organization of the cell nucleus. [less ▲]

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See detailNucleic acid detection by in situ molecular immunogold labeling procedures.
Thiry, Marc ULg

in Scanning Microscopy. Supplement (1996), 10

We have recently combined immunogold labeling procedures with molecular biology methods to pinpoint the precise locations of nucleic acids in biological material at the ultrastructural level. These new ... [more ▼]

We have recently combined immunogold labeling procedures with molecular biology methods to pinpoint the precise locations of nucleic acids in biological material at the ultrastructural level. These new immunocytological approaches involve the incorporation of labeled nucleotides in the nucleic acids present at the surface of ultrathin sections prior to immunogold labeling. The antibodies used recognize a nucleoside analogue (bromodeoxyuridine) or a hapten (biotin) employed to label nucleotides. Examples of high-resolution detection include DNA or RNA present in different substructures of cell nuclei, and in particular, in adenovirus-induced intranuclear regions of HeLa cells. In addition to being highly sensitive and specific, these new methods offer the possibility of studying the spatial distribution of nucleic acids in very well preserved, readily recognizable structures. [less ▲]

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See detailNucleic acid sensing at the interface between innate and adaptive immunity in vaccination
Desmet, Christophe ULg; Ishii, Ken J.

in Nature Reviews. Immunology (2012), 12(7), 479-491

The demand is currently high for new vaccination strategies, particularly to help combat problematic intracellular pathogens, such as HIV and malarial parasites. In the past decade, the identification of ... [more ▼]

The demand is currently high for new vaccination strategies, particularly to help combat problematic intracellular pathogens, such as HIV and malarial parasites. In the past decade, the identification of host receptors that recognize pathogen-derived nucleic acids has revealed an essential role for nucleic acid sensing in the triggering of immunity to intracellular pathogens. This Review first addresses our current understanding of the nucleic acid-sensing immune machinery. We then explain how the study of nucleic acid-sensing mechanisms not only has revealed their central role in driving the responses mediated by many current vaccines, but is also revealing how they could be harnessed for the design of new vaccines. [less ▲]

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See detailNucleolar alterations in human tumor cells induced by vitamin C and K3 during autoschizis
Jamison, J; Perlaky, L; Thiry, Marc ULg et al

in Molecular Biology of the Cell (2001), s12

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See detailNucleolar changes and fibrillarin redistribution following apatone treatment of human bladder carcinoma cells.
Jamison, James M; Gilloteaux, Jacques; Perlaky, Laszlo et al

in Journal of Histochemistry and Cytochemistry : Official Journal of the Histochemistry Society (2010), 58(7), 635-51

Ascorbate and menadione (Apatone) in a ratio of 100:1 kills tumor cells by autoschizis. In this study, vitamin-induced changes in nucleolar structure were evaluated as markers of autoschizis. Human ... [more ▼]

Ascorbate and menadione (Apatone) in a ratio of 100:1 kills tumor cells by autoschizis. In this study, vitamin-induced changes in nucleolar structure were evaluated as markers of autoschizis. Human bladder carcinoma (T24) cells were overlain with vitamins or with culture medium. Supernatants were removed at 1-hr intervals from 1 to 4 hr, and the cells were washed with PBS and prepared for assay. Apatone produced marked alterations in nucleolar structure including redistribution of nucleolar components, formation of ring-shaped nucleoli, condensation and increase of the proportion of perinucleolar chromatin, and the enlargement of nucleolar fibrillar centers. Immunogold labeling of the nucleolar rRNA revealed a granular localization in treated and sham-treated cells, and immunogold labeling of the rDNA revealed a shift from the fibrillar centers to the condensed perinucleolar chromatin. Fibrillarin staining shifted from the fibrillar centers and adjacent regions to a more homogeneous staining of the entire nucleolus and was consistent with the percentage of autoschizic cells detected by flow cytometry. Because autoschizis entails sequential reactivation of DNase I and DNase II, and because the fibrillarin redistribution following DNase I and Apatone treatment is identical, it appears that the nucleolar and fibrillarin changes are markers of autoschizis. [less ▲]

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See detailNucleolar structure across evolution : the transition between bi- and tricompartmentalized nucleoli lies within the class Reptilia
Franck, Claire; Lamaye, Françoise; Thelen, Nicolas ULg et al

Poster (2011, January 31)

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See detailNucleolar structure across evolution: the transition between bi- and tri-compartmentalized nucleoli lies within the class Reptilia.
Lamaye, Francoise; Galliot, Sonia; Alibardi, Lorenzo et al

in Journal of Structural Biology (2011), 174(2), 352-9

Two types of nucleolus can be distinguished among eukaryotic cells: a tri-compartmentalized nucleolus in amniotes and a bi-compartmentalized nucleolus in all the others. However, though the nucleolus ... [more ▼]

Two types of nucleolus can be distinguished among eukaryotic cells: a tri-compartmentalized nucleolus in amniotes and a bi-compartmentalized nucleolus in all the others. However, though the nucleolus' ultrastructure is well characterized in mammals and birds, it has been so far much less studied in reptiles. In this work, we examined the ultrastructural organization of the nucleolus in various tissues from different reptilian species (three turtles, three lizards, two crocodiles, and three snakes). Using cytochemical and immunocytological methods, we showed that in reptiles both types of nucleolus are present: a bi-compartmentalized nucleolus in turtles and a tri-compartmentalized nucleolus in the other species examined in this study. Furthermore, in a given species, the same type of nucleolus is present in all the tissues, however, the importance and the repartition of those nucleolar components could vary from one tissue to another. We also reveal that, contrary to the mammalian nucleolus, the reptilian fibrillar centers contain small clumps of condensed chromatin and that their surrounding dense fibrillar component is thicker. Finally, we also report that Cajal bodies are detected in reptiles. Altogether, we believe that these results have profound evolutionarily implications since they indicate that the point of transition between bipartite and tripartite nucleoli lies at the emergence of the amniotes within the class Reptilia. [less ▲]

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See detailLe nucléole : un organite cellulaire fondamental
Lepoint, Alain; Goessens, Guy ULg; Thiry, Marc ULg

in Revue de l'Association Belge des Technologies de Laboratoire (1987), 14

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See detailNucleolin binds specifically to an AP-1 DNA sequence and represses AP1-dependent transactivation of the matrix metalloproteinase-13 gene.
Samuel, Shaija; Twizere, Jean-Claude ULg; Beifuss, Katherine K et al

in Molecular Carcinogenesis (2008), 47(1), 34-46

Transcriptional regulation via activator protein-1 (AP-1) protein binding to AP-1 binding sites within gene promoter regions of AP-1 target genes plays a key role in controlling cellular invasion ... [more ▼]

Transcriptional regulation via activator protein-1 (AP-1) protein binding to AP-1 binding sites within gene promoter regions of AP-1 target genes plays a key role in controlling cellular invasion, proliferation, and oncogenesis, and is important to pathogenesis of arthritis and cardiovascular disease. To identify new proteins that interact with the AP-1 DNA binding site, we performed the DNA affinity chromatography-based Nucleotide Affinity Preincubation Specificity TEst of Recognition (NAPSTER) assay, and discovered a 97 kDa protein that binds in vitro to a minimal AP-1 DNA sequence element. Mass spectrometric fragmentation sequencing determined that p97 is nucleolin. Immunoblotting of DNA affinity-purified material with anti-nucleolin antibodies confirmed this identification. Nucleolin also binds the AP-1 site in gel shift assays. Nucleolin interacts in NAPSTER with the AP-1 site within the promoter sequence of the metalloproteinase-13 gene (MMP-13), and binds in vivo in chromatin immunoprecipitation assays in the vicinity of the AP-1 site in the MMP-13 promoter. Overexpression of nucleolin in human HeLa cervical carcinoma cells significantly represses AP-1 dependent gene transactivation of a minimal AP-1 reporter construct and of an MMP-13 promoter reporter sequence. This is the first report of nucleolin binding and transregulation at the AP-1 site. [less ▲]

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See detailThe Nucleolonema of Plant and Animal Cells: A Comparison
Deltour, Roger ULg; Motte, Patrick ULg

in Biology of the Cell (1990), 68(1), 5-11

Depending on the author and the animal or plant origin of the material under study, the term "nucleolonema" is used in different contexts and thus indicates nucleolar ultrastructures that are different ... [more ▼]

Depending on the author and the animal or plant origin of the material under study, the term "nucleolonema" is used in different contexts and thus indicates nucleolar ultrastructures that are different. In this paper, we attempt to clarify this state of affairs and to propose a definition for the plant cell nucleolonema. [less ▲]

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See detailThe nucleolus during the cell cycle.
Thiry, Marc ULg; Goessens, Guy ULg

Book published by R.G. Landes Company, Chapman and Hall (1996)

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See detailThe nucleolus in reptiles: Ultrastructural studies
Lamaye, F; Thiry, Marc ULg

Poster (2008)

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See detailNucleolus-associated bodies in meristematic cells of Pisum sativum
Jennane, A; Thiry, Marc ULg; Goessens, G

in Cell Biology International (1998), 22

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See detailThe nucleolus: structure/function relationship in RNA metabolism.
Hernandez-Verdun, Daniele; Roussel, Pascal; Thiry, Marc ULg et al

in Wiley Interdisciplinary Reviews. RNA (2010), 1(3), 415-31

The nucleolus is the ribosome factory of the cells. This is the nuclear domain where ribosomal RNAs are synthesized, processed, and assembled with ribosomal proteins. Here we describe the classical ... [more ▼]

The nucleolus is the ribosome factory of the cells. This is the nuclear domain where ribosomal RNAs are synthesized, processed, and assembled with ribosomal proteins. Here we describe the classical tripartite organization of the nucleolus in mammals, reflecting ribosomal gene transcription and pre-ribosomal RNA (pre-rRNA) processing efficiency: fibrillar center, dense fibrillar component, and granular component. We review the nucleolar organization across evolution from the bipartite organization in yeast to the tripartite organization in humans. We discuss the basic principles of nucleolar assembly and nucleolar structure/function relationship in RNA metabolism. The control of nucleolar assembly is presented as well as the role of pre-existing machineries and pre-rRNAs inherited from the previous cell cycle. In addition, nucleoli carry many essential extra ribosomal functions and are closely linked to cellular homeostasis and human health. The last part of this review presents recent advances in nucleolar dysfunctions in human pathology such as cancer and virus infections that modify the nucleolar organization. [less ▲]

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See detailThe nucleolus: When 2 became 3.
Thiry, Marc ULg; Lamaye, Françoise ULg; Lafontaine, Denis L. J.

in Nucleus (2011), 2(4),

Though the nucleolus is considered today as a multifunctional domain, its primary function is ribosome biogenesis. We have shown at the ultrastructural level that there are primarily two types of ... [more ▼]

Though the nucleolus is considered today as a multifunctional domain, its primary function is ribosome biogenesis. We have shown at the ultrastructural level that there are primarily two types of nucleolar organization: nucleoli containing three components in amniotes and two components in all other eukaryotes. In a recent report we made the additional, and surprising, finding that both types of nucleolar arrangement are found among living reptiles, viz. a bicompartmentalized nucleolus in turtles and a tricompartmentalized nucleolus in lizards, crocodiles and snakes. This latter organization occurs regardless of the species, the tissue or the developmental stages analyzed. These results are compatible with the view that the transition between bipartite and tripartite nucleoli coincided with the emergence of the amniotes within the Reptilia. They also support the previous hypothesis that turtles are primitive reptiles. The emergence in amniote vertebrates of a third nucleolar compartment might have imparted novel regulatory functions to the nucleolus, as well as perhaps, expanding the adaptability of ribosome synthesis to an ever changing environment, thus, enhancing the overall fitness of amniotic vertebrates. [less ▲]

Detailed reference viewed: 20 (6 ULg)