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See detailCollagen fibril disruption occurs early in primary guinea pig knee osteoarthritis.
Huebner, J. L.; Williams, J. M.; Deberg, Michelle ULg et al

in Osteoarthritis and Cartilage (2010), 18(3), 397-405

OBJECTIVE: A major barrier inhibiting the discovery of structural modifying agents for osteoarthritis (OA) is an incomplete understanding of early disease events. Herein, we investigated the time course ... [more ▼]

OBJECTIVE: A major barrier inhibiting the discovery of structural modifying agents for osteoarthritis (OA) is an incomplete understanding of early disease events. Herein, we investigated the time course of collagen II cleavage and fibril disruption in the well-validated Hartley guinea pig model of spontaneous OA of the knee. METHODS: Knee joints of 46 male Hartley guinea pigs were analyzed at 3 weeks, 2, 4, 7, 10, 12, and 18 months of age for histological severity of OA, cartilage collagen fibril disruption by semi-quantitative polarized light microscopy, and expression of type II collagen degradation biomarkers, 9A4 and Coll2-1, by immunohistochemistry. In addition, serum biomarkers specific for collagen II degradation, CTX-II, C2C, and Coll2-1 were quantified. RESULTS: Collagen fibril disruption and expression of the collagenase-generated cleavage neoepitope, 9A4, were observed as early as 2 months of age, despite the appearance of histological OA at 4 months of age. Only serum Coll2-1 increased coincident with the early disruption of the collagen fibril between 3 weeks and 7 months, in contrast to serum C2C, which did not change significantly or correlate with histological severity. Inversely, CTX-II declined dramatically from 3 weeks to 4 months and remaining low thereafter, coincident with growth plate turnover. CONCLUSIONS: Collagenase cleavage and disruption of the type II collagen network are early OA disease events in this model, preceding histological evidence of proteoglycan loss. The markedly different serum profiles of collagen II-related biomarkers during the early stages of disease development suggest compartmental segregation and temporal regulation of collagen degrading enzymes. [less ▲]

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See detailCollagen heterogeneity in normal human bone marrow
Bentley, S. A.; Alabaster, O.; Foidart, Jean-Michel ULg

in British Journal of Haematology (1981), 48(2), 287-91

Paraffin embedded sections of formalin fixed, decalcified, normal, human, vertebral bone were stained immunohistochemically for collagen types I, III and IV using the peroxidase--anti-peroxidase (PAP ... [more ▼]

Paraffin embedded sections of formalin fixed, decalcified, normal, human, vertebral bone were stained immunohistochemically for collagen types I, III and IV using the peroxidase--anti-peroxidase (PAP) technique. Preparations stained for collagen types I and III were virtually identical in appearance. These substrates were localized to the cytoplasm and fibrillar processes of a population of cells which were sparsely distributed within the haemopoietic compartment of the bone marrow, being particularly prominent in relation to the marrow sinusoids and fat spaces. They would thus appear to parallel the known distributions of reticulum cells, although their morphology differed in some respects from classical descriptions of the latter cell type. Type IV collagen was found in association with the endothelial lining of the sinusoids. Other connective tissue elements (bone, periosteum, endosteum, blood vessels, etc.) showed characteristic collagen heterogeneity. These results indicate that collagen is a significant component of the bone marrow connective tissue. [less ▲]

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See detailCollagen localization in normal and fibrotic human skeletal muscle.
Foidart, M.; Foidart, Jean-Michel ULg; Engel, W. K.

in Archives of Neurology (1981), 38(3), 152-7

The distribution of types I to IV collagen, types I and III p-N collagen, and fibronectin in human skeletal muscle was studied by immunofluorescence using purified antibodies to those proteins. In normal ... [more ▼]

The distribution of types I to IV collagen, types I and III p-N collagen, and fibronectin in human skeletal muscle was studied by immunofluorescence using purified antibodies to those proteins. In normal muscle, types I and III collagen, types I and III p-N collagen, and fibronectin were localized in the endomysium and perimysium. Type IV collagen was restricted to basement membrane. Type II collagen was not present. In Duchenne's musclar dystrophy and dermatomyositis/polymyositis (DM/PM), the prominently increased endomysial and perimysial fibrosis consisted of types I and III collagen, types I and III p-N collagen, and fibronectin. In DM/PM, thickening of the walls of perimysial venular and arteriolar vessels was associated with accumulation of types I and III collagen, types I and III p-N collagen, and fibronectin, as well as type IV collagen. There was no disease-specific accumulation of collagen, p-N collagen, or fibronectin. [less ▲]

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See detailCollagen synthesis in cultures of differentiating neural crest cells
Greenberg, J. H.; Foidart, Jean-Michel ULg; Greene, R. M.

in Cell Differentiation (1980), 9(3), 153-63

Neural crest cells from the cranial region of chick embryos were cultured in the presence of fetal calf serum in which they differentiate into melanocytes or in the presence of horse serum in which they ... [more ▼]

Neural crest cells from the cranial region of chick embryos were cultured in the presence of fetal calf serum in which they differentiate into melanocytes or in the presence of horse serum in which they differentiate into neuron-like cells. Undifferentiated cultures, as well as pigmented and neuronal cultures, incorporated [14C]proline into types I and III collagen and into non-collagenous proteins. When cells differentiated into melanocytes, the ratio of collagen to non-collagenous protein did not change. In contrast, in cultures where a portion of the cells differentiated into neuron-like cells, the ratio of collagen to non-collagenous protein was reduced. Indirect immunofluorescence studies using specific antibodies against collagen or procollagen types I, II, III, and IV demonstrated that undifferentiated neural crest cells, melanocytes and neuron-like cells stained only with antibody to type III procollagen, while fibroblastic cells present in some cultures stained only with antibody to type I procollagen. Our results demonstrate that although the types of collagen synthesized by neural crest cells do not change with time in culture, the relative amounts of collagen may reflect the pathway of differentiation of the cells. [less ▲]

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See detailCollagen, factor VIII antigen, and immunoglobulins in the human aqueous drainage channels.
Rodrigues, M. M.; Katz, S. I.; Foidart, Jean-Michel ULg et al

in Ophthalmology (1980), 87(4), 337-45

Twenty-five trabeculectomy specimens from patients with primary open angle glaucoma and chronic angle closure glaucoma, and 11 age-matched controls were examined by immunofluorescence and immunoperoxidase ... [more ▼]

Twenty-five trabeculectomy specimens from patients with primary open angle glaucoma and chronic angle closure glaucoma, and 11 age-matched controls were examined by immunofluorescence and immunoperoxidase techniques to determine the types of collagen, immunoglobulins, and the presence of factor VIII-related antigen in the human aqueous drainage channels. In the glaucoma cases and in controls, we demonstrated that the electron dense basement membrane-like material in the peripheral portion of the trabecular beams and in the juxtacanalicular meshwork, consists at least in part, of type IV collagen, a noncollagenous protein ("laminin") and fibronectin. Factor VIII-related antigen was demonstrated in conjunctival vessels of the control eyes. Schlemm's canal and the trabecular endothelial cells did not stain for factor VIII-related/antigen in any of the specimens examined. No deposits of IgA, IgM, IgG, and the C3 component of complement were detected in the aqueous drainage channels. [less ▲]

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See detailCollagens and non collagenous proteins in the human eye. I. Corneal stroma in vivo and keratocyte production in vitro.
Benezra, D.; Foidart, Jean-Michel ULg

in Current eye Research (1981), 1(2), 101-10

Human corneal stroma in situ and keratocyte activity in vitro were studied by the indirect immunofluorescent technique using highly purified antibodies to the various types of collagens, fibronectin and ... [more ▼]

Human corneal stroma in situ and keratocyte activity in vitro were studied by the indirect immunofluorescent technique using highly purified antibodies to the various types of collagens, fibronectin and laminin. Studying the localization of the various collagens in situ, it was observed that only type I collagen is present in the human corneal stroma. No positive immunofluorescence is obtained for type II or type III collagen. With type IV collagen, a bright immunofluorescence is observed at the level of Bowman's and Descemet's membranes. However, in vitro, the keratocyte cultures demonstrated the production of both type I and III collagens. No evidence for the production of type II or IV collagens was observed. Along with the collagens, human keratocytes in vitro also produced fibronectin. As for the non collagenous components of basement membrane (laminin), although a positive immunofluorescence was obtained the involvement of other cell-membrane glycoproteins in this reaction is not excluded. The possibility that a deregulation of type III collagen synthesis in vivo might be occurring also during certain pathologies and in corneal wound healing is postulated. [less ▲]

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See detailCollagens, laminin, fibronectin, and cytoskeletal composition of cells in syngeneic aortal vein grafts in the rat.
Stenmans, S.; Foidart, Jean-Michel ULg; Paavolainen, P. et al

in Research in Experimental Medicine (1985), 185(5), 355-66

The supradiaphragmatic vena cava of the rat was transplanted to the abdominal aorta in syngeneic recipients. The cells and the connective tissue matrix of these grafts were studied 3 days to 12 weeks ... [more ▼]

The supradiaphragmatic vena cava of the rat was transplanted to the abdominal aorta in syngeneic recipients. The cells and the connective tissue matrix of these grafts were studied 3 days to 12 weeks after transplantation by immunofluorescence staining of the cytoskeletal proteins desmin, vimentin, and myosin. The matrix proteins, collagen Types I and III, laminin, fibronectin, and fibrin(ogen) were similarly demonstrated. Blood coagulation Factor VIII was used as a marker for endothelial cells. Inflammatory cells invaded the graft during Week 1, but later on the grafts were crowded with cells containing vimentin. Intimal thickenings developed already after 1 week. Smooth muscle cells containing desmin proliferated in these thickenings. After transplantation collagen Type I increased in the graft, but collagen Type III rather decreased. During the phase of intense proliferation of smooth muscle cells the media contained a rich matrix of diffusely distributed laminin. The laminin of older grafts was confined mostly to the subintimal zone and to the intimal plaques. [less ▲]

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See detailCollapse of concrete columns during and after the cooling phase of a fire
Dimia, Mohamed Salah; Guenfoud, Mohamed; Gernay, Thomas ULg et al

in Journal of Fire Protection Engineering (2011), 21(4), 245263

This paper presents a study performed on the collapse of reinforced concrete columns subjected to natural fire conditions during and after the cooling phase of the fire. The aim is, first, to highlight ... [more ▼]

This paper presents a study performed on the collapse of reinforced concrete columns subjected to natural fire conditions during and after the cooling phase of the fire. The aim is, first, to highlight the phenomenon of collapse of concrete columns during and after the cooling phase of a fire and then, to analyze the influence of some determinant parameters. The main mechanisms that lead to this type of failure are found to be the delayed increase of the temperature in the central zones of the element and the additional loss of concrete strength during the cooling phase of the fire. A parametric study is performed considering different fires and geometric properties of the column. This shows that the most critical situations with respect to delayed failure arise for short fires and for columns with low slenderness or massive sections. [less ▲]

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See detailCollapse-revivals and population trapping in the m-photon mazer
Bastin, Thierry ULg; Solano, E.

Poster (2000)

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See detailA collapsed intermediate with nonnative packing of hydrophobic residues in the folding of TEM-1 beta-lactamase
Vanhove, M.; Lejeune, Annabelle ULg; GUILLAUME, G. et al

in Biochemistry (1998), 37(7), 1941-1950

The kinetics of refolding of TEM-1 beta-lactamase from solution in guanidine hydrochloride have been investigated on the manual and stopped-flow mixing time scales. The kinetics of change of far-UV ... [more ▼]

The kinetics of refolding of TEM-1 beta-lactamase from solution in guanidine hydrochloride have been investigated on the manual and stopped-flow mixing time scales. The kinetics of change of far-UV circular dichroism and of intrinsic and ANS fluorescence have been compared with changes in the quenching of fluorescence by acrylamide as a probe of the accessibility of solvent to tryptophan. The binding of ANS points to hydrophobic collapse in the very early stages of folding which take place in the burst phase. This is accompanied by regain of 60-65% of-native ellipticity, indicating formation of a significant proportion of secondary structure, Also in the burst phase, the tryptophan residues, which are largely exposed to solvent in the native protein, become less accessible to acrylamide, and the intrinsic fluorescence increases markedly. An early intermediate is thus formed in which tryptophan is more buried than in the native protein. Further intermediates are formed over the next 20 s. Quenching by acrylamide increases during this period, as the transient nonnative state is disrupted and the tryptophan residue(s) become(s) reexposed to solvent, The two slowest phases are determined by the isomerization of incorrect prolyl isomers, but double jump tryptophan fluorescence and acrylamide quenching experiments show little, if any, effect of proline isomerization on the earlier phases, Hydrophobic collapse thus occurs to a folding intermediate in which there is a nonnative element of structure which has to rearrange in the later steps of folding, resulting in a nonhierarchical folding pathway. The C-terminal W290 is suggested as being involved in the nonnative intermediate. beta-Lactamase provides further evidence for the occurrence of nonnative intermediates in protein folding. [less ▲]

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See detailCollapsing and reswelling kinetics of thermoresponsive polymers on surfaces: a matter of confinement and constraints
Willet, Nicolas ULg; Gabriel, Sabine ULg; Jérôme, Christine ULg et al

in Soft Matter (2014), 10

We report on the collapsing and reswelling ability of grafted poly(methyl vinyl ether) chains of different molecular architectures. In order to study the influence of constraints and confinement of the ... [more ▼]

We report on the collapsing and reswelling ability of grafted poly(methyl vinyl ether) chains of different molecular architectures. In order to study the influence of constraints and confinement of the chains, the polymer was grafted onto AFM tips, as a model of a curved nano-sized surface, and onto macroscopic silicon substrates for comparison purposes. AFM-based force spectroscopy experiments were performed to characterise at the nanoscale the temperature-dependent collapsing process and the reversibility to the swollen state on both substrates. The reversible character of the thermoresponsive transition and its kinetics were shown to greatly depend on the polymer architecture and the constraints encountered by the chains. [less ▲]

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See detailLe collectaire de l'abbé Thierry de Stavelot
George, Philippe ULg

in Liège. Autour de l'an mil, la naissance d'une principauté (Xe-XIIe siècle) (2000)

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See detailLa collecte de l'information. Pour qui ? Pourquoi ? Comment ?
Claustriaux, Jean-Jacques ULg

in Notes de Statistique et d'Informatique (2012), (3), 7

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See detailLa collecte des déchets en Wallonie : organisation et performances
Gautier, Axel ULg

Scientific conference (2014, April 03)

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See detailLa collecte des déchets en Wallonie : organisation et performances
Gautier, Axel ULg; Reginster, Sophie ULg

in Regards Economiques (2013), (106),

En Wallonie, la collecte des déchets est fréquemment déléguée par les communes à une intercommunale ou à un collecteur privé. Par ailleurs, de plus en plus de communes utilisent des conteneurs à puce. Cet ... [more ▼]

En Wallonie, la collecte des déchets est fréquemment déléguée par les communes à une intercommunale ou à un collecteur privé. Par ailleurs, de plus en plus de communes utilisent des conteneurs à puce. Cet article compare les performances en termes de coûts de ces différentes alternatives. [less ▲]

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See detailCollecter et analyser ses données (dans le domaine de l'Information et de la communication)
Tomasovic, Dick ULg

Scientific conference (2008, May 15)

Detailed reference viewed: 3 (0 ULg)