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See detailFeeding habits in a dimorphic metapopulation of the tiger salamander Ambystoma tigrinum nebulosum
Denoël, Mathieu ULg; Wissinger, Scott; Whiteman, Howard

Conference (2003)

Facultative paedomorphosis in salamanders refers to the presence of two ontogenetic pathways in natural populations – paedomorphosis, in which individuals retain gills at the adult stage, and ... [more ▼]

Facultative paedomorphosis in salamanders refers to the presence of two ontogenetic pathways in natural populations – paedomorphosis, in which individuals retain gills at the adult stage, and metamorphosis, in which larvae metamorphose. The Mexican Cut Nature Preserve (Colorado, USA) is composed of numerous ponds which are inhabited by paedomorphic and metamorphic tiger salamanders. While paedomorphs usually stay in the same aquatic habitat all their life, metamorphs may leave water and colonize other ponds. The aim of this study was to determine the feeding habits of the two morphs from this metapopulation. To this end, adults were caught by dip-netting, stomach-flushed, measured and marked. Paedomorphs were only found in permanent waters. Metamorphs were present in all habitats, but particularly in the temporary ponds. Diet differed between ponds – reflecting their invertebrate composition – with a preponderance of either microcrustaceans, fairy shrimp or insect larvae. In ponds inhabited by the two morphs, paedomorphs consumed more prey items. Because dry mass and energy content varied between invertebrates, feeding on some of them, such as fairy shrimp in the temporary ponds where they are abundant, gave high energy intake to the predators. Because such resources are only available to the dispersive morph, metamorphs are at the advantage in being able to avoid competition with paedomorphs in permanent ponds and in using transient resources from the productive temporary waters. [less ▲]

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See detailp-mode Oscillations of alpha Cen A
Thoul, Anne ULg; Scuflaire, Richard ULg; Vatovez, B. et al

in Astrophysics & Space Science (2003), 284

Models of alpha Cen A & B have been computed using the masses determined by Pourbaix et al. (2002) and the data derived from the spectroscopic analysis of Neuforge and Magain (1997). The seismological ... [more ▼]

Models of alpha Cen A & B have been computed using the masses determined by Pourbaix et al. (2002) and the data derived from the spectroscopic analysis of Neuforge and Magain (1997). The seismological data obtained by Bouchy and Carrier (2001, 2002) do help improve our knowledge of the evolutionary status of the system. All the constraints are satisfied with a model which gives an age of about 6 Gyr for the binary. [less ▲]

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See detailBinding and migration across fibronectin and VCAM-1 of cycling hematopoietic progenitor cells.
Gothot, André ULg; Giet, Olivier ULg; Huygen, Sandra et al

in Leukemia & Lymphoma (2003), 44(8), 1379-83

Using different experimental approaches, it has been established that transplantability of hematopoietic/stem progenitor cells is ineffective during transit through the cell cycle. Although primitive stem ... [more ▼]

Using different experimental approaches, it has been established that transplantability of hematopoietic/stem progenitor cells is ineffective during transit through the cell cycle. Although primitive stem cells are responsive to mitogenic stimulation in optimized ex vivo conditions, defective engraftment of generated cells may limit their detection in standard transplantation models as well as their use in clinical cell therapy. The activation level of adhesion receptors is modulated by stimulation of cytokine receptors via "inside-out" signaling. This prompted us to study the interactions of progenitor cells with fibronectin (Fn) in different phases of the cell cycle. We first demonstrated that adhesion to Fn was stimulated in S/G2 + M as compared to G0/G1, in ex vivo cultured CD34+ cells, with a predominant usage of very late antigen (VLA)-5 over that of VLA-4. We next determined that maximal Fn binding in active phases of the cell cycle limited cell motility toward stromal cell-conditioned medium. It was also observed that VLA-4 and VLA-5 ability to mediate adhesion or migration varied independently during cell cycle transit. Finally, in synchronized progenitor cells executing a first cell cycle ex vivo, a reversible increase in Fn binding was associated with a reversible decrease in adhesion to vascular cell-adhesion molecule (VCAM)-1. Overall, these observations suggest that defective engraftment of cycling stem/progenitor cells may result, at least in part, from abnormal trafficking related to changes in the activation level of adhesion receptors. [less ▲]

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See detailGeneration of spatially correlated wind histories
Denoël, Vincent ULg

in Proceedings of the first Internation Conference on Finite Element Methods (2003)

Turbulent wind is a natural and therefore random phenomenon. The analysis of flexible structures subjected to turbulent wind requires, in a finite element approach, the resolution of a system of ... [more ▼]

Turbulent wind is a natural and therefore random phenomenon. The analysis of flexible structures subjected to turbulent wind requires, in a finite element approach, the resolution of a system of stochastic differential equations. It is supposed that the characteristics of the structure are perfectly known; thus the stochastic aspect of the problem comes from the random loading only. As the turbulent wind is most commonly characterized by its frequency content, the resolution of this equation is generally performed in the frequency domain. All governing equations must therefore be linear. If this can be reasonably supposed for the structure, this hypothesis is not mathematically justified for the wind loading. When the non linear behaviour of any part of the structure has to be accounted for, the resolution in the frequency domain is not valid anymore. It is then necessary to compute, with a step-by-step dynamic analysis, the response of the structure to a series of generated wind histories. In a finite element approach, this is for example achieved thanks to Newmark’s or Wilson’s methods. Averaging across the ensemble of the computed time-varying responses allows then to recover statistical results that a stochastic analysis would provide. This analysis method is known as a stochastic Monte Carlo simulation. After having emphasised the need to represent correctly the coherence between wind pressures at different points of the structure, this paper will present a method for generating a set of correlated wind histories that must be used in a finite element analysis. Finally an example of application of the presented method will prove its efficiency. [less ▲]

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See detailMeasure Noun constructions : an instance of semantically-driven grammaticalization
Brems, Lieselotte ULg

in International Journal of Corpus Linguistics (2003), 8(2), 283-312

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See detailThe Tricolor incident: Pathology, age composition and sex ratio of stranded birds
Jauniaux, Thierry ULg; Masure, S.

in meeting report (2003)

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See detailT-cell reconstitution after unmanipulated, CD8-depleted or CD34-selected nonmyeloablative peripheral blood stem-cell transplantation.
Baron, Frédéric ULg; Schaaf-Lafontaine, Nicole ULg; Humblet-Baron, Stéphanie ULg et al

in Transplantation (2003), 76(12), 1705-13

BACKGROUND: We have previously shown that CD8 depletion or CD34 selection of peripheral blood stem cells (PBSC) reduced the incidence of acute graft-versus-host disease (GvHD) after nonmyeloablative stem ... [more ▼]

BACKGROUND: We have previously shown that CD8 depletion or CD34 selection of peripheral blood stem cells (PBSC) reduced the incidence of acute graft-versus-host disease (GvHD) after nonmyeloablative stem-cell transplantation (NMSCT). In this study, we analyze the effect of CD8 depletion or CD34 selection of the graft on early T-cell reconstitution. METHODS: Nonmyeloablative conditioning regimen consisted in 2 Gy total-body irradiation (TBI) alone, 2 Gy TBI and fludarabine, or cyclophosphamide and fludarabine. Patients 1 to 18 received unmanipulated PBSC, patients 19 to 29 CD8-depleted PBSC, and patients 30 to 35 CD34-selected PBSC. RESULTS: T-cell counts, and particularly CD4+ and CD4CD45RA+ counts, remained low the first 6 months after nonmyeloablative stem-cell transplantation (NMSCT) in all patients. CD34 selection (P<0.0001) but not CD8 depletion of PBSC significantly decreased T-cell chimerism. Donor T-cell count was similar in unmanipulated compared with CD8-depleted PBSC recipients but was significantly lower in CD34-selected PBSC recipients (P=0.0012). T cells of recipient origin remained stable over time in unmanipulated and CD8-depleted PBSC patients but expanded in some CD34-selected PBSC recipients between day 28 and 100 after transplant. Moreover, whereas CD8 depletion only decreased CD8+ counts (P<0.047), CD34 selection reduced CD3+(P<0.001), CD8+(P<0.016), CD4+ (P<0.001), and CD4+CD45RA+ (P<0.001) cell counts. T-cell repertoire was restricted in all patients on day 100 after hematopoietic stem-cell transplantation but was even more limited after CD34 selection (P=0.002). CONCLUSIONS: Despite of the persistence of a significant number of T cells of recipient origin, T-cell counts were low the first 6 months after NMSCT. Moreover, contrary with CD8 depletion of the graft that only affects CD8+ lymphocyte counts, CD34 selection dramatically decreased both CD8 and CD4 counts. [less ▲]

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See detailPrevention de la nephropathie diabetique: de la microalbuminurie a l'insuffisance renale terminale.
Weekers, Laurent ULg; Scheen, André ULg; Rorive, Georges ULg

in Revue Médicale de Liège (2003), 58(5), 297-306

Diabetic nephropathy is one of the leading causes of end-stage renal failure in western countries. This disease develops over several years. Early stages, if they are detected in time, can lead to ... [more ▼]

Diabetic nephropathy is one of the leading causes of end-stage renal failure in western countries. This disease develops over several years. Early stages, if they are detected in time, can lead to preventive treatment at a moment when the disease is still reversible. This paper reviews the main primary and secondary preventive measures that have been proven efficacious. Those are essentially the optimal treatment of hyperglycaemia and hypertension, and probably the use of agents that specifically block the renin-angiotensin axis. We briefly discuss the results of the main studies that have led to those conclusions. [less ▲]

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See detailL'etude clinique du mois. L'etude EUROPA: protection cardio-vasculaire avec le perindopril chez les patients avec coronaropathie stable.
Scheen, André ULg; Legrand, Victor ULg

in Revue Médicale de Liège (2003), 58(11), 713-6

The multicentre placebo-controlled double-blind "EUropean trial on Reduction Of cardiac events with Perindopril in patients with stable coronary Artery disease" (EUROPA) assessed whether the angiotensin ... [more ▼]

The multicentre placebo-controlled double-blind "EUropean trial on Reduction Of cardiac events with Perindopril in patients with stable coronary Artery disease" (EUROPA) assessed whether the angiotensin-converting-enzyme inhibitor perindopril reduces cardiovascular risk in a population with stable coronary heart disease and no apparent heart failure, whatever the associated cardiovascular risk. Patients were randomly assigned perindopril 8 mg once daily (n = 6110) or matching placebo (n = 6108). After a mean follow-up of 4.2 years, a relative risk reduction of 20% (95% CI 9-29, p = 0.0003) was observed in the combined primary endpoint (cardiovascular death, myocardial infarction, or cardiac arrest) in the group treated with perindopril as compared to placebo. About 50 patients needed to be treated for a period of 4 years to prevent one major cardiovascular event. This benefit was consistent in all predefined subgroups. According to these results, treatment with perindopril, on top of other preventive medications, should be considered in all patients with stable coronary heart disease. [less ▲]

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See detailComment j'explore ... la controverse a propos de la place de l'hyperglycemie provoquee par voie orale en clinique.
Luyckx, Françoise ULg; Scheen, André ULg

in Revue Médicale de Liège (2003), 58(11), 701-5

The oral glucose tolerance test (OGTT) has been widely used for the diagnosis of diabetes mellitus, gestational diabetes or impaired glucose tolerance. However, since 1997, OGTT is not considered anymore ... [more ▼]

The oral glucose tolerance test (OGTT) has been widely used for the diagnosis of diabetes mellitus, gestational diabetes or impaired glucose tolerance. However, since 1997, OGTT is not considered anymore as the first choice test for the diagnosis of diabetes mellitus or impaired glucose tolerance, being replaced by fasting glycaemia. Numerous studies, however, stressed the discrepancies between these two diagnostic approaches, so that OGTT still has defenders as a useful tool to diagnose diabetes. Besides, emphasis has been recently put on both postprandial hyperglycaemia, considered as a major cardiovascular risk factor, and impaired glucose tolerance as a predictor of progression toward overt type 2 diabetes, two parameters well addressed by the OGTT. Thus, even if the place to be reserved to the OGTT is controversial, in our opinion, this test still has a place in clinical biology. [less ▲]

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See detailLe medicament du mois. Gliclazide a liberation modifiee (Uni Diamicron).
Scheen, André ULg

in Revue Médicale de Liège (2003), 58(10), 641-5

Gliclazide modified release that has been recently launched by Servier (Uni Diamicron 30 mg) is a new formulation of gliclazide to be given once daily. The original hydrophilic matrix improves the ... [more ▼]

Gliclazide modified release that has been recently launched by Servier (Uni Diamicron 30 mg) is a new formulation of gliclazide to be given once daily. The original hydrophilic matrix improves the biodisponsibility of gliclazide and allows a progressive release of the drug that better parallels the 24-hour glycaemic profile of patients with type 2 diabetes mellitus. Such characteristics may explain the rather low risk of hypoglycaemic episodes and the morning administration should contribute to improve patient's compliance. As the common formulation of gliclazide, the modified release formulation is indicated in the treatment of type 2 diabetes, in adult subjects, when diet, exercise and weight loss are insufficient to restore an adequate metabolic control. It may be used alone or in combination with metformin, glitazones, acarbose or insulin, with the same general principles of use as for the classical formulation of gliclazide. [less ▲]

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See detailInterruption prematuree des etudes ASCOT et CARDS de prevention cardio-vasculaire avec l'atorvastatine chez le sujet hypertendu ou diabetique: compromis entre ethique et statistique en medecine factuelle.
Scheen, André ULg

in Revue Médicale de Liège (2003), 58(9), 585-90

The Anglo-Scandinavian Cardiac Outcomes Trial--Lipid Lowering Arm (ASCOT-LLA), performed in hypertensive patients with coronary risk and the Collaborative AtoRvastatin Diabetes Study (CARDS), performed in ... [more ▼]

The Anglo-Scandinavian Cardiac Outcomes Trial--Lipid Lowering Arm (ASCOT-LLA), performed in hypertensive patients with coronary risk and the Collaborative AtoRvastatin Diabetes Study (CARDS), performed in diabetic patients, also at coronary risk, were prematurely stopped, at the special request of the Data Safety Monitoring Board. Indeed, an interim analysis demonstrated the efficacy of atorvastatin, at a daily dosage of 10 mg as compared to placebo, in the prevention of major cardiovascular events, so that it appeared unethical to continue the study until the end. At the glance of these observations, the ethical and statistical aspects of such prevention clinical trials are discussed, in particular when the premature interruption of the ongoing study appears mandatory, with respect of the main rules of evidence-based medicine. [less ▲]

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See detailLe medicament du mois. Le vardenafil (Levitra).
Scheen, André ULg

in Revue Médicale de Liège (2003), 58(9), 576-9

Vardenafil (Levitra), recently launched in Belgium by Bayer and Glaxo-SmithKline, is a new drug that potently and selectively inhibits phosphodiesterase type 5 (PDE5) in the cavernosum tissue of the penis ... [more ▼]

Vardenafil (Levitra), recently launched in Belgium by Bayer and Glaxo-SmithKline, is a new drug that potently and selectively inhibits phosphodiesterase type 5 (PDE5) in the cavernosum tissue of the penis. Inhibition of PDE5 blocks the hydrolysis of cyclic guanosine monophosphate (GMPc) and results in increased arterial blood flow leading to enlargement of the corpus cavernosum and resulting in erection. In controlled clinical trials, vardenafil at least doubled the rate of successful erections as compared to placebo, whatever the evaluation parameter considered and the subgroup of patients studied. Vardenafil is thus indicated in the treatment of patients with erectile dysfunction. It is presented as 5, 10 and 20 mg tablets and the usual dose is 10 mg to be ingested 25 to 60 minutes before sexual activity. Vardenafil has a more potent inhibitory activity of PDE5 in vitro than sildenafil or tadalafil while its pharmacokinetics in vivo is somewhat more rapid than that of the two other compounds. The dosage of vardenafil may be reduced to 5 mg (especially in older individuals) to improve tolerance or be increased up to 20 mg (especially in the presence of organic diseases aggravating erectile dysfunction) to improve efficacy. Contra-indications (co-administration with drugs increasing nitric oxide) and side-effects (headache and flushing due to vasodilatation) of vardenafil are similar to those of other PDE5 inhibitors. [less ▲]

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See detailL'adiponectine: une nouvelle adipocytokine.
Lebas, Eglantine ULg; Paquot, Nicolas ULg; Scheen, André ULg

in Revue Médicale de Liège (2003), 58(9), 554-8

Adipose tissue is not simply a store of excess energy, but also secretes a variety of proteins into circulating blood that influence systemic metabolism. These include tumor necrosis factor (TNF-alpha ... [more ▼]

Adipose tissue is not simply a store of excess energy, but also secretes a variety of proteins into circulating blood that influence systemic metabolism. These include tumor necrosis factor (TNF-alpha), plasminogen activator inhibitor type 1 (PAI-1), leptin, resistine and adiponectin. These are collectively known as adipocytokines. Adiponectin (also referred to as AdipoQ, Acrp 30, apM1 or GBP28) is a novel adipose-specific protein. A recent genome study mapped a susceptibility locus for type 2 diabetes and the metabolic syndrome on chromosome 3q27, where the adiponectin gene is located. Adiponectin is a peculiar adipocytokine because in contrast to the markedly increased levels of many others, as leptin or TNF-alpha, its level is reduced in obesity and type 2 diabetes. The administration of thiazolidinediones, which are synthetic PPARs-gamma ligands, significantly increases the plasma adiponectin concentrations, an effect that could improve insulin sensitivity. Thus, the administration of adiponectin may provide a novel treatment modality for insulin resistance and type 2 diabetes. [less ▲]

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See detailComment je previens ... les maladies cardio-vasculaires par une approche pharmacologique combinee: y a-t-il place pour une polypill"?"
Scheen, André ULg; Lefebvre, Pierre ULg; Kulbertus, Henri ULg

in Revue Médicale de Liège (2003), 58(9), 527-33

In the June 28, 2003 issue of the British Medical Journal, an extensive literature survey based on various large meta-analyses of the efficacy and safety of the reduction of four cardiovascular risk ... [more ▼]

In the June 28, 2003 issue of the British Medical Journal, an extensive literature survey based on various large meta-analyses of the efficacy and safety of the reduction of four cardiovascular risk factors (cholesterol, arterial blood pressure, platelet aggregation, homocysteine) leads to the conclusion that a combined pharmacological intervention should reduce ischaemic heart disease events by 88% and strokes by 80% in at risk individuals. Therefore, a new paradigm is proposed for the prevention of cardiovascular diseases. This new strategy would consist in the systematic prescription to people with a history of heart attack or stroke, those with any form of obliterative atherosclerotic vascular disease or diabetes, and everyone aged 55 and older of a fixed combination of 6 pharmacological agents independently of initial risk factor profile.... Such pharmacological formulation, called "polypill", should contain a statin, three blood pressure lowering drugs (each at half standard dose), aspirin (75 mg/day) and folic acid (0.8 mg/day). We discuss the pros and cons of this new paradigm. However, the efficacy of such "polypill" remains to be demonstrated in a large controlled clinical trial as well as its superiority as compared to a classical approach of cardiovascular prevention based upon the individual optimal correction of each risk factor thanks a dose titration of each pharmacological compound. [less ▲]

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See detailAlcool, sensibilite a l'insuline et diabete sucre.
Magis, Delphine ULg; Jandrain, Bernard ULg; Scheen, André ULg

in Revue Médicale de Liège (2003), 58(7-8), 501-7

The relationship between alcohol consumption and insulin resistance shows a U-shaped curve: insulin resistance is minimal in individuals with regular mild to moderate alcohol consumption and increases in ... [more ▼]

The relationship between alcohol consumption and insulin resistance shows a U-shaped curve: insulin resistance is minimal in individuals with regular mild to moderate alcohol consumption and increases in both heavy drinkers and subjects without any alcohol consumption. These favourable metabolic effects on insulin sensitivity of moderate alcohol consumption may explain the significant reduction in the development of type 2 diabetes and the risk of cardiovascular complications reported in numerous epidemiological studies. This latter effect has also reported in patients with diabetes mellitus, although this observation remains controversial. However, alcohol consumption could increase the global risk of hypoglycaemia, both in the fasting state and after a meal (reactive hypoglycaemia) in both diabetic and nondiabetic subjects. These latter effects may result from a direct inhibition of gluconeogenesis, from a reduced secretion of counterregulatory hormones and/or from an alcohol-induced inappropriate behaviour. [less ▲]

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See detailLe syndrome metabolique: definitions et donnees epidemiologiques.
Scheen, André ULg; Luyckx, Françoise ULg

in Revue Médicale de Liège (2003), 58(7-8), 479-84

The metabolic syndrome is strongly related to visceral obesity and associated with a high risk of cardiovascular morbidity and mortality. Since the original description of Reaven in 1988, several working ... [more ▼]

The metabolic syndrome is strongly related to visceral obesity and associated with a high risk of cardiovascular morbidity and mortality. Since the original description of Reaven in 1988, several working definitions have been proposed, especially by the World Health Organisation in 1998-99, the National Cholesterol Education Program (NCEP-ATP III) Expert Panel in the United States in 2001 and the European Group for the Study of Insulin Resistance (EGIR) in 2002. The present paper attempts at comparing these various definitions and at reporting epidemiological data both in North America and in Europe, especially in Belgium. The prevalence is generally higher in men than in women and strongly increases with age. Overall, one may estimate that around 20% of adults have a metabolic syndrome, which should therefore be considered as an important public health problem. [less ▲]

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See detailNumeros a theme et numero d'ete.
Kulbertus, Henri ULg; Scheen, André ULg

in Revue Médicale de Liège (2003), 58(7-8), 453-4

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See detailLe medicament du mois. Glucovance dans le diabete de type 2, une association fixe metformine-glibenclamide pour faciliter le traitement d'une maladie bipolaire.
Scheen, André ULg

in Revue Médicale de Liège (2003), 58(6), 448-52

Glucovance, recently launched by Merck-Lipha (Glucovance 500 mg/2.5 mg and Glucovance 500 mg/5 mg), is a fixed combined therapy of a sulphonylurea (glibenclamide 2.5 or 5 mg) and a biguanide (metformin ... [more ▼]

Glucovance, recently launched by Merck-Lipha (Glucovance 500 mg/2.5 mg and Glucovance 500 mg/5 mg), is a fixed combined therapy of a sulphonylurea (glibenclamide 2.5 or 5 mg) and a biguanide (metformin 500 mg), indicated for the treatment of type 2 diabetes in adult patients. The only current official indication in Belgium is the substitution of a dual therapy with metformin and glibenclamide in patients with a stable and adequate metabolic control. The fixed combination aims at simplifying patient's treatment in order to improve compliance despite polymedication. In addition, it allows targeting synergistically the two main abnormalities of type 2 diabetes, i.e. the insulin secretory defect and the insulin resistance. [less ▲]

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