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See detailPreconditioning of the tumor vasculature and tumor cells by intermittent hypoxia: implications for anti-cancer therapies
Martinive, Philippe ULg

Poster (2007, January)

Hypoxia is a common feature in tumors associated with an increased resistance of tumor cells to therapies. In addition to O(2) diffusion-limited hypoxia, another form of tumor hypoxia characterized by ... [more ▼]

Hypoxia is a common feature in tumors associated with an increased resistance of tumor cells to therapies. In addition to O(2) diffusion-limited hypoxia, another form of tumor hypoxia characterized by fluctuating changes in pO(2) within the disorganized tumor vascular network is described. Here, we postulated that this form of intermittent hypoxia promotes endothelial cell survival, thereby extending the concept of hypoxia-driven resistance to the tumor vasculature. We found that endothelial cell exposure to cycles of hypoxia reoxygenation not only rendered them resistant to proapoptotic stresses, including serum deprivation and radiotherapy, but also increased their capacity to migrate and organize in tubes. By contrast, prolonged hypoxia failed to exert protective effects and even seemed deleterious when combined with radiotherapy. The use of hypoxia-inducible factor-1alpha (HIF-1alpha)-targeting small interfering RNA led us to document that the accumulation of HIF-1alpha during intermittent hypoxia accounted for the higher resistance of endothelial cells. We also used an in vivo approach to enforce intermittent hypoxia in tumor-bearing mice and found that it was associated with less radiation-induced apoptosis within both the vascular and the tumor cell compartments (versus normoxia or prolonged hypoxia). Radioresistance was further ascertained by an increased rate of tumor regrowth in irradiated mice preexposed to intermittent hypoxia and confirmed in vitro using distinctly radiosensitive tumor cell lines. In conclusion, we have documented that intermittent hypoxia may condition endothelial cells and tumor cells in such a way that they are more resistant to apoptosis and more prone to participate in tumor progression. Our observations also underscore the potential of drugs targeting HIF-1alpha to resensitize the tumor vasculature to anticancer treatments. PMID: 17178869 [PubMed - indexed for MEDLINE] [less ▲]

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See detailThird Belgian multicentre survey of antibiotic susceptibility of anaerobic bacteria
Wybo, Ingrid; Piérard, Denis ULg; Verschraegen, Inge et al

in Journal of Antimicrobial Chemotherapy (2007), 59(1), 132-139

Objectives: To collect recent data on the susceptibility of anaerobes and to compare them with results from previous studies. Methods: Four hundred and forty-three anaerobic clinical isolates from various ... [more ▼]

Objectives: To collect recent data on the susceptibility of anaerobes and to compare them with results from previous studies. Methods: Four hundred and forty-three anaerobic clinical isolates from various body sites were prospectively collected from October 2003 to February 2005 in nine Belgian hospitals. MICs were determined for nine anti-anaerobic and three recently developed antibiotics. Results: Most Gram-negative bacilli except Fusobacterium spp. were resistant to penicillin. Piperacillin/tazobactam, metronidazole, chloramphenicol, meropenem and amoxicillin/clavulanic acid were very active against all groups, but only 86% of Bacteroides fragilis group strains were susceptible to the latter. Cefoxitin, cefotetan and clindamycin were less active. In particular, only 62%, 52% and 48% of B. fragilis group strains were susceptible, respectively. Clindamycin shows a continuing decrease in activity, as 83% were still susceptible in 1987 and 66% in 1993-94. Anti-anaerobic activity of the new antibiotics is interesting, with MIC50 and MIC90 of 1 and > 32 mg/L for moxifloxacin, 2 and 4 mg/L for linezolid and 0.5 and 8 mg/L for tigecycline. Conclusions: The susceptibility of anaerobic bacteria remains stable in Belgium, except for clindamycin, which shows a continuous decrease in activity. However, for each of the tested antibiotics, at least a few resistant organisms were detected. Consequently, for severe infections involving anaerobic bacteria, it could be advisable to perform microbiological testing instead of relying on known susceptibility profiles. Periodically monitoring background susceptibility remains necessary to guide empirical therapy. [less ▲]

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See detailUne déontologie manipulée ?
Durand, Pascal ULg; Grégoire, Arnaud

Article for general public (2007)

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See detailMiroir interne déformant de l'image de soi : élaboration conceptuelle intégrant la clinique et les découvertes récentes des neurosciences
Scholl, Jean-Marc ULg; Philippe, Paule ULg

Poster (2007, January)

Neurosciences : Un réseau neuronal spécifiquement référé au "self" du sujet est mis en évidence en neuroimagerie (Ph Fossati). Il intervient pour se remémore des attributs référés au self. Ce réseau est ... [more ▼]

Neurosciences : Un réseau neuronal spécifiquement référé au "self" du sujet est mis en évidence en neuroimagerie (Ph Fossati). Il intervient pour se remémore des attributs référés au self. Ce réseau est différent de celui qui permet au sujet de donner des attributs à d'autres individus. Le réseau référé au self permet d'être en contact immédiat avec l'image et la connaissance de soi. De plus, le rappel mnésique des attributs positifs et négatifs référés au self met en jeu des réseaux neuronaux différents. Les attributs positifs référés au self activent la région préfrontale antéromédiane droite, les attributs négatifs référés au self la région préfrontale dorsolatérale droite. Le sujet sain active les deux réseaux de façon simultanée pour restituer une image de soi intégrée. Définition conceptuelle: Le "miroir interne" – distingué de l'objet qui lui est présenté – correspond¬ au réseau neuronal référé spécifiquement au self. Ce réseau accède à l'image de soi. S'il y a un dysfonctionnement du réseau référé au self, il restitue une image déformée de soi, et le "miroir interne" devient déformant. Le sujet associera son identité à cette image déformée. Clinique du «miroir interne déformant de l'image de soi» : Le regard de l'enfant sur lui-même lui renvoie une image plus négative que ce que ses interlocuteurs ne perçoivent de lui. Dès le départ, l'enfant a une mauvaise perception de lui-même. Lorsqu'un interlocuteur lui fait une remarque, l'enfant bascule dans une image déformée et bien plus négative que celle que ne lui prête l'interlocuteur. Un dysfonctionnement de ces réseaux déséquilibre la balance et ne fait apparaître "qu'une seule couleur" dans le "miroir interne" par une restitution mnésique univoque : ou des attributs positifs, ou des attributs négatifs. Une prépondérance de l'image négative évoque un terrain dépressif, des personnalités évitante ou dépendante. Une prépondérance de l'image positive évoque des personnalités narcissiques, une image mégalomaniaque. Un dysfonctionnement neuronal peut induire une labilité et une instabilité de cette image (borderline), ou, une bascule rapide en "on-off" d'images positives et négatives de soi (rencontrée en pédopsychiatrie). Une psychoéducation permet la prise de conscience de ce miroir interne déformant. [less ▲]

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See detailCutting planes from lattice-point-free polyhedra
Louveaux, Quentin ULg

Conference (2007, January)

In this talk, we generalize the concept of a split (that leads to split cuts) to any lattice-point-free polyhedron. We show how we can generate cutting planes for a polyhedron from these objects ... [more ▼]

In this talk, we generalize the concept of a split (that leads to split cuts) to any lattice-point-free polyhedron. We show how we can generate cutting planes for a polyhedron from these objects. Associated to any lattice-point-free polyhedron, we define a "split-dimension" (which is equal to 1 in the case of a split in the usual sense). We then consider the operation of adding to a polyhedron all cutting planes that we can obtain from considering all the lattice-point-free polyhedra with a split-dimension lower or equal to d. We call the obtained object the "d-dimensional split closure" of the initial polyhedron. We discuss whether this object is again a polyhedron or not. As an important illustration, we focus on objects of split-dimension equal to 1 or 2. [less ▲]

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See detailA novel 24-base pair deletion in the coding region of CCR5 in an African population
Karasi, Jean Claude ULg

in AIDS (2007), 21(1), 111-113

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See detailLe depistage du cancer colorectal
Piront, Patricia ULg; Louis, Edouard ULg; Belaiche, Jacques ULg et al

in Revue Médicale de Liège (2007), 62(1), 15-20

Colorectal cancer is the second leading cause of death in Northern countries and need a national screening program to reduce mortality and improve quality of life. Screening has to be cost-effective and ... [more ▼]

Colorectal cancer is the second leading cause of death in Northern countries and need a national screening program to reduce mortality and improve quality of life. Screening has to be cost-effective and acceptable for patients. Many screening tools, invasive or not, are existing and often debated: FOBT, sigmoidoscopy and complete colonoscopy. New tools are in development and have to be evaluated in current practice: virtual colonoscopy, new endoscopic technologies, DNA on faeces or proteomics with markers in serum. [less ▲]

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See detailAllo maman ici bébé: les technologies de la reproduction chez les équidés
Ponthier, Jérôme ULg; Deleuze, Stefan ULg

Article for general public (2007)

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See detailThe contribution of processing fluency to preference : a comparison with familiarity-based recognition
Willems, Sylvie ULg; Van der Linden, Martial ULg; Bastin, Christine ULg

in European Journal of Cognitive Psychology (2007), 19(1), 119-140

There is a great deal of evidence supporting the idea that, when a stimulus is processed fluently, it is more likely to be judged as pleasant. However, this influence of fluency on preference judgement ... [more ▼]

There is a great deal of evidence supporting the idea that, when a stimulus is processed fluently, it is more likely to be judged as pleasant. However, this influence of fluency on preference judgement seems to depend on several experimental conditions. So we tried to better understand these conditions via a comparison with recognition and by manipulating some aspects of the procedure (test format) and material (similarity and figure-ground contrast of the stimuli). Two experiments showed that some conditions maximally induce the use of processing fluency in a preference judgement, as in a recognition task. We discuss the implications of these findings for the well-documented discrepancy-attribution hypothesis (Whittlesea [less ▲]

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See detailNew Kids on the Blogs
Dejasse, Erwin ULg; Paques, Frédéric ULg

in Neuvième art 2.0. (2007), 13

The article deals with of the phenomenon of Comic Blogs

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See detailLe lycée Léonie de Waha
Charlier, Sébastien ULg

in Nouvelles du Patrimoine (Les) (2007), 115

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See detailMise en place de l’autocontrôle : ce que cela implique dans vos exploitations
Belleflamme, Christel ULg; Di Tanna, Sybille ULg; Moerman, John et al

Article for general public (2007)

Suite à une directive européenne, la mise en place d’un système de gestion de la sécurité des denrées alimentaires est devenue obligatoire en Belgique. Outre la création de l’Agence Fédérale pour la ... [more ▼]

Suite à une directive européenne, la mise en place d’un système de gestion de la sécurité des denrées alimentaires est devenue obligatoire en Belgique. Outre la création de l’Agence Fédérale pour la Sécurité de la Chaîne Alimentaire, une législation en matière d’autocontrôle de notification obligatoire et de traçabilité a été mise en place. Les agriculteurs qui transforment et commercialisent leur production sont directement concernés. Nous vous proposons de mettre en avant quelques conséquences pratiques qui en découlent et l’encadrement proposé par Gembloux en la matière [less ▲]

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See detailMonitoring an odour in the environment with an electronic nose : requirements for the signal processing
Romain, Anne-Claude ULg; Delva, Julien ULg; Nicolas, Jacques ULg

Conference (2007, January)

Artificial olfaction system (the so-called electronic nose) is a very promising tool to monitor the malodour in the field. Usual measurement techniques of odour use human olfaction or conventional ... [more ▼]

Artificial olfaction system (the so-called electronic nose) is a very promising tool to monitor the malodour in the field. Usual measurement techniques of odour use human olfaction or conventional analytical techniques. The first category represents the real odour perception but is not applicable to measure continuously bad odours in the field. The second class of techniques gives the mixture composition but not the global information representative of the odour perception. The e-nose has the potentialities to combine "the odour perception" and the "monitoring in the field". However to be able to reach that goal, the signal processing has to be adapted to work in complex environment. The research group in Arlon has more than ten years experience in the measure of environmental malodours in the field. The paper presents the minimal requirements that the group considers as essential for artificial olfaction system to become successful for this application. [less ▲]

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See detailSufasalazine unveils a contact-independent HSV-TK/ganciclovir gene therapy bystander effect in malignant gliomas
Robe, Pierre ULg; Nguyen-Khac, Minh-Tuan ULg; Lambert, Frédéric ULg et al

in International Journal of Oncology (2007), 30(1), 283-290

The efficacy of HSV-TK/ganciclovir-based gene therapy on malignant gliomas largely relies on the amplitude of the bystander effect. In these experiments, the anti-inflammatory drug Sulfasalazine increased ... [more ▼]

The efficacy of HSV-TK/ganciclovir-based gene therapy on malignant gliomas largely relies on the amplitude of the bystander effect. In these experiments, the anti-inflammatory drug Sulfasalazine increased the HSV-TK/ganciclovir bystander effect in C6, 9L and LN18 cells but not in U87 glioma cells. Using bi-compartmental culture devices and conditioned medium transfer experiments, we showed that in C6, 9L and LN18 cells but not in U87 cells, Sulfasalazine also unveiled a new, contact-independent mechanism of HSV-TK/ganciclovir bystander effect. Upon treatment with ganciclovir, human LN18-TK but not U87-TK cells synthetized and released TNF-alpha in the culture medium. Sulfasalazine sensitized glioma cells to the toxic effect of TNF-alpha. and enhanced its secretion in LN18-TK cells in response to GCV treatment. The caspase-8 inhibitor Z-IETD-FMK and a blocking antibody to TNF-alpha both inhibited the contact-independent bystander effect in LN18 cells. Taken together, these results suggest that TNF-alpha mediates the contact-independent bystander effect in LN18 cells. The treatment with GCV and/or Sulfasalazine of tumor xenografts consisting of a mix of 98% C6 and 2% C6-TK cells shows that Sulfasalazine is also a potent adjunct to the in vivo treatment of gliomas. [less ▲]

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See detailMinimization of Production Cost by use of an Automatic Cost Assessment Method and Simulation
Caprace, Jean-David ULg; Bair, Frédéric ULg; Losseau, Nicolas ULg et al

in The Euro-Asia Maritime Network (EAMARNET) (2007, January)

This paper will present different ways to minimize cost in shipbuilding industry. Amongst them we have the production simulation methods, the cost assessment methods and the optimization methods. Nowadays ... [more ▼]

This paper will present different ways to minimize cost in shipbuilding industry. Amongst them we have the production simulation methods, the cost assessment methods and the optimization methods. Nowadays, cost assessment is a key task of an integrated ship design. The various methods to estimate the production cost differ with the known information (input data). The less information is detailed, the earlier a method can be used in the design process. The more information is used, the better we can assess the differences between design alternatives. The methods presented here and the “design for production” concept promise to increase the productivity trough the following points: a more accurate cost estimation, an improvement in the deadlines planning and the production schedule, a progress in distribution of the workload between the various production workshops, a better knowledge of the individual costs that will permit to reduce the global cost. In order to illustrate our work, we present in this paper three methods to decrease the global cost of a ship. [less ▲]

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See detailChanges in diatom, pollen, and chironomid assemblages in response to a recent volcanic event in Lake Galletue (Chilean Andes)
Urrutia, Roberto; Araneda, Alberto; Cruces, Fabiola et al

in Limnologica (2007), 37(1), 49-62

Several lakes in Chile are near important volcanic areas where eruption impacts can limit the quality of lacustrine sediments for reconstructing past environmental changes. In this study, we report ... [more ▼]

Several lakes in Chile are near important volcanic areas where eruption impacts can limit the quality of lacustrine sediments for reconstructing past environmental changes. In this study, we report changes in diatoms, pollen, and chironomids assemblages after a tephra deposition in Lake Galletue (Chilean Andes). A sediment core obtained from Lake Galletue (40 m water depth) was sliced in I cm intervals and subsamples were taken to analyze each proxy. Pb-210 and 137 Cs activities were measured to obtain the geochronology and mineralogical analyses were performed to determine the mineral composition of the tephra. Diatom species composition and productivity were modified when the lake received the tephra; Aulacoseira granulata decreased and was later replaced by Cyclotella af. glomerata. After the tephra input, Aulacoseira granulata abundance increased to pre-disturbance levels and Cyclotella af. glomerata decreased. These changes seem to suggest a momentary increase in lake nutrient levels after the tephra deposition. Chironomid assemblages also decreased in head capsules just after the tephra deposition, but the most important change was the replacement of Ablabesmyia by Parakiefferiella, probably due to the sedimentological changes produced by the input of coarse tephra grains. Furthermore, unlike other studies, chironomid assemblages in Lake Galletue did not show a decrease drastically in diversity within the tephra layer. The pollen analysis indicated that, prior to the volcanic event, the vegetal community was dominated by Nothofagus sp., Araucaria araucana, and Blechnum sp.-type. After the tephra deposition, the same taxa are dominant, indicating that the volcanic event seems not produce changes in the vegetation. Nevertheless, within the tephra layer it is possible to see an increase in Poaceae, which represent - due to the percolation process - the effect of eruption on the vegetation. According to our results, diatoms were the most sensitive proxy for describing the changes produced by tephra deposition into the aquatic ecosystem and, despite the noticeable changes in its sedimentological properties; the lake seems to have a high resilience capacity, allowing it to return to pre-tephra input conditions. (c) 2006 Elsevier GmbH. All rights reserved. [less ▲]

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See detailEstimation of air quality degradation due to Saharan dust at Nouakchott, Mauritania, from horizontal visibility data
Ozer, Pierre ULg; Laghdaf, MBOM; Lemine, S. O. M. et al

in Water, Air & Soil Pollution (2007), 178(1-4), 79-87

It is now irrefutable that air pollution caused by large amounts of Total Suspended Particulates (TSP) and respiratory particulates or Particulate Matter less than 10 mu m in aerodynamic diameter (PM10 ... [more ▼]

It is now irrefutable that air pollution caused by large amounts of Total Suspended Particulates (TSP) and respiratory particulates or Particulate Matter less than 10 mu m in aerodynamic diameter (PM10) has numerous undesired consequences on human health. Air quality degradation far from the African continent, in the US and in Europe, caused by high concentrations of African dust, is seen as a major threat even though most of these countries are very distant from the Sahara. Surprisingly, no estimates of TSP or PM10 levels near the Saharan dust source are available. Based on horizontal visibility observations which are reduced by the presence of dust in the atmosphere, TSP and PM10 levels are estimated throughout the year 2000 at Nouakchott-Airport, Mauritania, using relations found in the literature. It appears that concentrations of particles are significant both in terms magnitude and frequency, as the 24-hour PM10 thresholds established by the US EPA National Ambient Air Quality Standards and the EU Limits Values for Air Quality were exceeded 86 and 137 times, respectively. The average annual concentration is far above air quality standards and estimated at 159 mu g m(-3) for TSP and 108 mu g m(-3) for PM10. These very high particulate levels are likely to represent an important public health hazard and should be considered as a major environmental risk. [less ▲]

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See detailMapping the updating process: common and specific brain activations across different versions of the running span task
Collette, Fabienne ULg; Van der Linden, Martial ULg; Laureys, Steven ULg et al

in Cortex : A Journal Devoted to the Study of the Nervous System & Behavior (2007), 43(1), 146-158

Neuroimaging studies exploring the neural substrates of executive functioning have only rarely investigated whether the non-executive characteristics of the experimental executive tasks could contribute ... [more ▼]

Neuroimaging studies exploring the neural substrates of executive functioning have only rarely investigated whether the non-executive characteristics of the experimental executive tasks could contribute to the observed brain activations. The aim of this study was to determine cerebral activity in three different tasks involving the updating executive function. The experimental updating tasks required subjects to process strings of items (respectively letters, words, and sounds) of unknown lengths, and then to recall or identify a specific number of presented items. Conjunction and functional connectivity analyses demonstrated that the cerebral areas activated by all three experimental tasks are the left frontopolar cortex, bilateral dorsolateral prefrontal and premotor cortex, bilateral intraparietal sulcus, right inferior parietal lobule and cerebellum. Some regions of this network appear to be more specific to each updating task. These results clearly indicate that the neural substrates underlying a specific executive process (in this case, updating) are modulated by the exact requirements of the task (such as the material to process or the kind of response) and the specific cognitive processes associated with updating. [less ▲]

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See detailGuide de rédaction du TFE en médecine générale
Vanmeerbeek, Marc ULg

Learning material (2007)

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