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See detailCytotoxic aporphine alkaloids from Cassytha filiformis L
Stévigny, caroline; De Pauw-Gillet, Marie-Claire ULg; de Hoffmann, E et al

Poster (2001)

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See detailCytotoxic aporphine alkaloids from Cassytha filiformis.
Stevigny, C.; Block, S.; De Pauw-Gillet, Marie-Claire ULg et al

in Planta Medica (2002), 68(11), 1042-4

Purification of a cytotoxic crude alkaloid extract of Cassytha filiformis led to the isolation of four known aporphine alkaloids: neolitsine, dicentrine, cassythine (= cassyfiline) and actinodaphnine ... [more ▼]

Purification of a cytotoxic crude alkaloid extract of Cassytha filiformis led to the isolation of four known aporphine alkaloids: neolitsine, dicentrine, cassythine (= cassyfiline) and actinodaphnine. Their structures were determined by analysis of spectroscopic data. All isolated alkaloids were tested for their cytotoxic activities on cancer and non-cancer cell lines in vitro. Neolitsine was the most active against HeLa and 3T3 cells (IC 50 :21.6 microM, and 21.4 microM, respectively). Cassythine and actinodaphnine showed the highest activity against Mel-5 (IC 50 : 24.3 microM and 25.7 microM, respectively) and HL-60 (IC 50 : 19.9 microM and 15.4 microM, respectively). This is the first report on the cytotoxic activity of C. filiformis extract and of neolitsine and cassythine. Furthermore, the complete NMR data of cassythine and actinodaphnine are given here for the first time. [less ▲]

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See detailCytotoxic Effects of Aroclor 1254 on Ultrastructure and Biochemical Parameters in Cultured Foetal Rat Hepatocytes
Thomé, Jean-Pierre ULg; Roelandt, L.; Goffinet, Gerhard ULg et al

in Toxicology (1995), 98(1-3), 83-94

The cytotoxicity of a commercial PCB mixture, Aroclor 1254, was assessed on cultured foetal rat hepatocytes. Under control conditions, dexamethasone stimulates immature hepatocytes to differentiate into ... [more ▼]

The cytotoxicity of a commercial PCB mixture, Aroclor 1254, was assessed on cultured foetal rat hepatocytes. Under control conditions, dexamethasone stimulates immature hepatocytes to differentiate into both hepatocytes and biliary epithelial cells. Consequently, foetal rat hepatocytes maintain, in vitro, a liver-like organization with spaces corresponding to the lumen of biliary canalicules, many mitochondria, and a well-developed rough endoplasmic reticulum (RER). This in vivo-like organization of cultured rat hepatocytes remains unchanged in medium supplemented with Aroclor 1254 at concentrations below 25 microM. In the 25-125 microM concentration range, however, PCBs severely alter some cellular organelles, notably causing important development of the RER and the appearance of cytoplasmic lacunae containing laminated concentric membrane arrays. In addition, the number of lipid droplets increases, the glycogen islets disappear, and dramatic local alterations of the mitochondrial cristae occur. In exposed and unexposed cells, the following biochemical parameters were measured: the DNA content, protein synthesis, lipid peroxidation, and urea formation. The results show that Aroclor 1254 at concentrations exceeding 25 microM (but not at lower concentrations) causes irreversible damage to cultured hepatocytes. The observed ultrastructural modifications are in good agreement with several in vivo studies on rat liver. Thus, isolated foetal rat hepatocytes have considerable potential as an alternative to whole animals for use in (eco)toxicological studies. [less ▲]

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See detailCytotoxic interactions of 5-fluorouracil and nucleoside analogues in vitro
Li, Y-X; COUCKE, Philippe ULg; Paschoud, N et al

in Anticancer Research (1997), 17(1A), 21-27

The cytotoxic interaction of combined 5-fluorouracil (5-FU) with different nucleoside analogues was investigated in vitro on a colon (WiDr) and a breast (MCF-7) cancer cell line. Azidothymidine (AZT), 3 ... [more ▼]

The cytotoxic interaction of combined 5-fluorouracil (5-FU) with different nucleoside analogues was investigated in vitro on a colon (WiDr) and a breast (MCF-7) cancer cell line. Azidothymidine (AZT), 3'-deoxy-2', 3'-didehydrothymidine (D4T), 5-iododeoxyuridine (IdUrd) and 2',3'-dideoxycytidine (DDC) were tested at different concentrations (5-600 microM) as modulators of 5-FU. The experimental endpoints were cellular viability and cell cycle distribution. The combination of 5-FU and AZT or D4T yielded supra-additive cytotoxic effects in both cell lines at all concentrations. On WiDr, IdUrd at high concentrations of 50 and 100 microM showed a supra-additive effect whereas at low concentrations (5, 10 and 20 microM) the effect was antagonistic. 5-FU combined with IdUrd produced a synergistic effect on MCF-7 cells at all concentrations. DDC antagonised the toxic effect of 5-FU on the WiDr cell line. In WiDr cells, a significant increase in the overall S-phase was observed 48 and 72 hours after exposure to D4T, AZT and DDC at the low concentration of 10 microM. On the contrary, this accumulation in S-phase was not present in MCF-7 cells. The combined effect of 5-FU and nucleoside analogues in vitro is dependent on the type and concentration of nucleosides and the cell-line tested. AZT, D4T and IdUrd are more likely to be subjected to more intensive in vitro and in vivo research as far as modulation of 5-FU toxicity is concerned. [less ▲]

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See detailCytotoxic T-lymphocyte-associated protein 4-Ig effectively controls immune activation and inflammatory disease in a novel murine model of leaky severe combined immunodeficiency
Humblet-Baron, Stephanie; Schönefeldt, Susan; Garcia-Perez, Josselyn E et al

in Journal of Allergy and Clinical Immunology (The) (in press)

Background: Severe combined immunodeficiency (SCID) can be caused by loss-of-function mutations in genes involved in the DNA recombination machinery, such as RAG1, RAG2 or DCLRE1C. Defective DNA ... [more ▼]

Background: Severe combined immunodeficiency (SCID) can be caused by loss-of-function mutations in genes involved in the DNA recombination machinery, such as RAG1, RAG2 or DCLRE1C. Defective DNA recombination causes a developmental block in T cells and B cells, resulting in high susceptibility to infections. Hypomorphic mutations in the same genes can also give a partial loss of T cells, in a spectrum including leaky SCID (LS) and Omenn syndrome (OS). These patients not only develop life-threatening infections due to immunodeficiency, but also develop inflammatory/autoimmune conditions due to the presence of autoreactive T cells. Objective: We sought to develop a preclinical model that fully recapitulates the symptoms of LS/OS patients including a model for testing therapeutic intervention. Methods: We generated a novel mutant mouse (Dclre1c leaky) that develops a LS phenotype. Mice were monitored for diseases and immune phenotype and immune function were evaluated using flow cytometry, ELISA and histology. Results: Dclre1c leaky mice present with a complete blockade of B cell differentiation, with a leaky block in T cell differentiation resulting in an oligoclonal TCR repertoire and enhanced cytokine secretion. Dclre1c leaky mice also developed inflammatory symptoms including wasting, dermatitis, colitis, hypereosinophilia and high IgE levels. Development of a preclinical murine model for LS allowed the testing of potential treatment, with administration of CTLA4-Ig reducing disease symptoms and immunological disturbance, resulting in increased survival. Conclusion: These data suggest that CTLA4-Ig should be evaluated as a potential treatment of inflammatory symptoms in LS and OS patients. [less ▲]

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See detailCytotoxic triterpenoid saponins from the roots of Cephalaria gigantea
Tabatadze, Nino; Elias, Riad; Faure, Robert et al

in Chemical & Pharmaceutical Bulletin (2007), 55(1), 102-105

Three new oleanane-type saponins, giganteosides L (1)(I), M (2) and N (3) along with eight known ones were isolated from the roots of Cephalaria gigantea. Their structures were established as 3-O-[-D ... [more ▼]

Three new oleanane-type saponins, giganteosides L (1)(I), M (2) and N (3) along with eight known ones were isolated from the roots of Cephalaria gigantea. Their structures were established as 3-O-[-D-galactopyranosyl-(12)--D-glucuronopyranosyl]-28-O-[-D-glucopyranosyl-(16)--D-glucopyranosyl]-oleanolic acid, 3-O-[-D-galactopyranosyl-(12)--D-glucuronopyranosyl]-28-O-[-D-glucopyranosyl-(16)--D-glucopyranosyl]-hederagenin, 3-O-[-L-rhamnopyranosyl-(12)--D-glucuronopyranosyl]-28-O-[-D-glucopyranosyl-(16)--D-glucopyranosyl]-hederagenin, resp., by means of spectroscopic methods (1D and 2D NMR, HR-ESI-MS). Cytotoxic activity of monodesmosides was investigated in vitro using three cancer cell lines, namely, human non pigmented melanoma MEL-5 and human leukemia HL-60. Giganteosides D (4) and E (5) showed antiproliferative effect on human cell lines with IC50 values in the range 3.15-7.5 M. [less ▲]

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See detailCYTOTOXICITY EVALUATION OF A STARCH-BASED HYDROGEL LOADED WITH HYDROXYAPATITE AND CALCIUM CARBONATE FOR BONE REGENERATION
Flores Arriaga, J.C.; Cerda, Bernardino; Escobar, V. et al

Poster (2015)

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See detailCytotoxicity of Stimulated Equine Neutrophils on Equine Endothelial Cells in Culture
Benbarek, H.; Grulke, Sigrid ULg; Deby-Dupont, G. et al

in Equine Veterinary Journal (2000), 32(4), 327-33

We studied the interactions of isolated equine neutrophils with endothelial cells in culture, mimicking a situation of acute inflammation. Our main purpose was to demonstrate that the supernatant of ... [more ▼]

We studied the interactions of isolated equine neutrophils with endothelial cells in culture, mimicking a situation of acute inflammation. Our main purpose was to demonstrate that the supernatant of activated neutrophils was sufficient to damage endothelial cells. Equine endothelial cells (from carotid arteries) were covered either with increased numbers of equine neutrophils stimulated by phorbol myristate acetate, or with the supernatant collected after an in vitro stimulation of the neutrophils. Cytotoxicity was estimated by the release of preincorporated 51Cr, and by light microscopy observations. To assert the specific role of reactive oxygen species, endothelial cells were treated by the hypoxanthine/xanthine oxidase (X/XOx) system (production of superoxide anion and hydrogen peroxide), and by hypochlorite (product of the activity of myeloperoxidase). A strong cytotoxicity was found with stimulated neutrophils; microscopic observations indicated a loss of 50% of the endothelial cells and morphological alterations in the remaining cells. The supernatant of stimulated neutrophils was cytotoxic, in correlation with the number of neutrophils used to obtain the supernatant, and with the supernatant concentration of myeloperoxidase. The cytotoxicity of the X/XOx system was weak, but was increased by myeloperoxidase. Hypochlorite was highly toxic. We concluded that the supernatant of stimulated neutrophils was sufficient to obtain cytotoxic effects on the endothelium, in the absence of a direct contact between endothelium and neutrophils, and that this cytotoxicity was mainly linked to the activity of myeloperoxidase. From these in vitro results, it can be extrapolated that in pathologies characterised by an important activation of neutrophils, damage can spread to cells and tissues away from the inflammation focus. [less ▲]

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See detailCytotoxicity towards human endothelial cells, induced by neutrophil myeloperoxidase: protection by ceftazidime.
Mathy, Marianne ULg; Deby, Ginette ULg; Deby, C. et al

in Mediators of Inflammation (1995), 4(6), 437-43

We investigated the effects of the antibiotic ceftazidime (CAZ) on the cytolytic action of the neutrophil myeloperoxidase-hydrogen peroxide-chloride anion system (MPO/H(2)O(2)/Cl(-)). In this system ... [more ▼]

We investigated the effects of the antibiotic ceftazidime (CAZ) on the cytolytic action of the neutrophil myeloperoxidase-hydrogen peroxide-chloride anion system (MPO/H(2)O(2)/Cl(-)). In this system, myeloperoxidase catalyses the conversion of H(2)O(2) and CI(-) to the cytotoxic agent HOCl. Stimulated neutrophils can release MPO into the extracellular environment and then may cause tissue injury through direct endothelial cells lysis. We showed that human umbilical vein endothelial cells (HUVEC) were capable of taking up active MPO. In presence of H(2)O(2) (10(-4) M), this uptake was accompanied by cell lysis. The cytolysis was estimated by the release of (51)Cr from HUVEC and expressed as an index of cytotoxicity (IC). Dose dependent protection was obtained for CAZ concentrations ranging from 10(-5) to 10(-3) M;this can be attributed to inactivation of HOCl by the drug. This protection is comparable to that obtained with methionine and histidine, both of which are known to neutralize HOCl. This protection by CAZ could also be attributed to inactivation of H(2)O(2), but when cytolysis was achieved with H(2)O(2) or O(2) (-) generating enzymatic systems, no protection by CAZ was observed. Moreover, the peroxidation activity of MPO (action on H(2)O(2)) was not affected by CAZ, while CAZ prevented the chlorination activity of MPO (chlorination of monochlorodimedon). So, we concluded that CAZ acts via HOCl inactivation. These antioxidant properties of CAZ may be clinically useful in pathological situations where excessive activation of neutrophils occurs, such as in sepsis. [less ▲]

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See detailCZC-GC miniaturized analysis of POPs in 20 µL blood
L'Homme, Benjamin ULg; Focant, Jean-François ULg

Conference (2013, May)

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See detailCZE separation of basic and acidic drug by use of cyclodextrin additives
Bechet, I.; Fillet, Marianne ULg; Fotsing, Lucas ULg et al

Poster (1995)

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See detailCzochralski crystal growth, thermal conductivity, and magnetic properties of Pr(x)La(1- x)AlO3, where x = 1, 0.75, 0.55, 0.40, 0
Turczynski, S.; Orlinski, K.; Pawlak, D. A. et al

in Crystal Growth & Design (2011), 11(4), 1091-1097

Crystals of Pr(x)La(1-x)AlO3 solid solution have been grown by the Czochralski method for the first time, to the best of our knowledge. Crystals with high praseodymium concentration tend to grow spirally ... [more ▼]

Crystals of Pr(x)La(1-x)AlO3 solid solution have been grown by the Czochralski method for the first time, to the best of our knowledge. Crystals with high praseodymium concentration tend to grow spirally. The color of the crystals changes with chemical composition. X-ray diffraction shows an increase of the lattice constants with an increase in lanthanum ion concentration. The thermal conductivity has been investigated in the temperature range from 5 to 300 K. Completely different behavior of thermal conductivity is observed at low temperatures for the investigated crystals, whereas it remains roughly constant at high temperatures. The values of magnetic susceptibility lie within the expected range that could be expected for a paramagnetic material. (Figure Presented) © 2011 American Chemical Society. [less ▲]

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See detail'D’abord sa manière étoit gottique'. L'œuvre peint de Bernard van Orley jusqu'au début des années 1520
Galand, Alexandre ULg

Doctoral thesis (2011)

Les années 1510 et 1520 apparaissent comme un moment crucial pour l’introduction de la Renaissance dans les anciens Pays-Bas. Or, cette période coïncide avec la première période d’activité de Bernard van ... [more ▼]

Les années 1510 et 1520 apparaissent comme un moment crucial pour l’introduction de la Renaissance dans les anciens Pays-Bas. Or, cette période coïncide avec la première période d’activité de Bernard van Orley, un témoin majeur de cette époque de transition. Jusqu’à présent, la recherche a surtout envisagé l’artiste par le prisme de ses magnifiques tapisseries. De la fin de la première décennie du 16e siècle à 1521 où il signe le monumental Polyptyque de Job et de Lazare (Bruxelles, MRBAB/KMSKB, Inv. 1822), l’artiste a pourtant élaboré un œuvre peint de plus en plus perméable aux formes en provenance de la péninsule italienne. Ce changement de perspective a-t-il entraîné des différences importantes en termes de pratiques d’atelier ? Comment peuvent être caractérisées de manière précise les œuvres constituant le noyau dur d’un catalogue aux frontières mouvantes ? En quoi les documents d’archives peuvent-ils donner un nouvel éclairage sur l’activité de l’artiste ? Ces questions sont au centre d’un travail qui se donne pour ambition de renouveler la vision de la peinture de Bernard van Orley, domaine jusqu’à aujourd’hui négligé. [less ▲]

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See detailD’affaire sociale à affaire médiatique : cas d’étude de trois affaires en Tunisie.
Luceno Moreno, Marta ULg

Scientific conference (2013, May 31)

Les recherches sur la contestation en Tunisie se sont fortement focalisées sur les médias sociaux dans la publicisation de la dénonciation publique, par contre ces études négligent souvent les étapes ... [more ▼]

Les recherches sur la contestation en Tunisie se sont fortement focalisées sur les médias sociaux dans la publicisation de la dénonciation publique, par contre ces études négligent souvent les étapes précédentes et postérieures à la médiatisation via les réseaux sociaux. Notre recherche a l’ambition d’analyser ces étapes creuses en se concentrant notamment sur la place des auteurs dans la construction de la dénonciation et de la justification (Boltanski, 1991), ainsi que sur le processus de construction de problèmes publics dont certaines affaires ont fait l’objet. En partant de la vision des acteurs, nous étudierons la construction symbolique des « cadres d’interprétation » (Goffman 1974, Gitlin,1980) qui servent à la cause. Parallèlement, nous analyserons la médiatisation de ces cadres d’interprétation dans les médias occidentaux afin de mettre en évidence les correspondances et discordances avec les cadres mis en avant par les acteurs. Ceci nous permettra d’investiguer l’évolution du traitement médiatique de la dénonciation publique en Tunisie depuis les derniers moments de la dictature de Ben Ali à nos jours ; ainsi que nous donner des pistes pour comprendre la façon dont ces événements attirent le regard médiatique extérieur, en mettant l’accent sur l’importance donnée par les médias à des questions liées à la religion et aux droits des femmes. [less ▲]

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See detailD'Alexandrie à Constantinople : l'acquisition et la transmission du savoir en anatomie et en chirurgie, de la période hellénistique à la période byzantine
Marganne, Marie-Hélène ULg

in Perdicoyanni-Paleologou, Helen (Ed.) Anatomy and Surgery from Antiquity to the Renaissance (2016)

This paper proposes to reconstruct the means of acquisition and transmission of anatomical and surgical knowledge in the period from the death of Alexander the Great (323 BC) to the reign of Constantine ... [more ▼]

This paper proposes to reconstruct the means of acquisition and transmission of anatomical and surgical knowledge in the period from the death of Alexander the Great (323 BC) to the reign of Constantine VII Porphyrogenitus (913-959), through the study of archaeological, epigraphic, papyrological and manuscript sources. These testimonies bring to view strategies such as observation, experimentation, analogy and imitation, as well as oral and written teaching, redaction and copy of books (illustrated or not), elaboration of commentaries, abridgments, questionnaires and word-lists. A distinction will be drawn between texts which were addressed to physicians and medical students, on the one hand, those which were destined to philiatroi and to an educated readership, and finally those which might interest copyists and eventually tachygraphists. [less ▲]

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See detailD'Alexandrie à Damas et retour. La poste privée à l'époque mamlouke à la lumière d'une commission accomplie pour le compte d'un Vénitien (821 A.H./1418 È.C.)
Bauden, Frédéric ULg

in Vermeulen, Urbain; D'hulster, Kristof (Eds.) Egypt and Syria in the Fatimid, Ayyubid and Mamluk Eras VI. Proceedings of the 14th and 15th International Colloquium Organized at the Katholieke Universiteit Leuven in May 2005 and May 2006 (2010)

Detailed reference viewed: 166 (13 ULg)