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See detailTaxonomy of stock market indices
Bonanno, G.; Vandewalle, Nicolas ULg; Mantegna, R. N.

in Physical Review. E : Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics (2000), 62(6),

We investigate sets of financial nonredundant and nonsynchronously recorded time series. The sets are composed by a number of stock market indices located all over the world in five continents. By ... [more ▼]

We investigate sets of financial nonredundant and nonsynchronously recorded time series. The sets are composed by a number of stock market indices located all over the world in five continents. By properly selecting the time horizon of returns and by using a reference currency we find a meaningful taxonomy. The detection of such a taxonomy proves that interpretable information can be stored in a set of nonsynchronously recorded time series. [less ▲]

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See detailRegulation of Etioplast Pigment-Protein Complexes, Inner Membrane Architecture, and Protochlorophyllide a Chemical Heterogeneity by Light-Dependent Nadph:Protochlorophyllide Oxidoreductases a and B
Franck, Fabrice ULg; Sperling, U.; Frick, G. et al

in Plant Physiology (2000), 124(4), 1678-96

The etioplast of dark-grown angiosperms is characterized by the prolamellar body (PLB) inner membrane, the absence of chlorophyll, and the accumulation of divinyl and monovinyl derivatives of ... [more ▼]

The etioplast of dark-grown angiosperms is characterized by the prolamellar body (PLB) inner membrane, the absence of chlorophyll, and the accumulation of divinyl and monovinyl derivatives of protochlorophyll(ide) a [Pchl(ide) a]. Either of two structurally related, but differentially expressed light-dependent NADPH:Pchlide oxidoreductases (PORs), PORA and PORB, can assemble the PLB and form dark-stable ternary complexes containing enzymatically photoactive Pchlide-F655. Here we have examined in detail whether these polypeptides play redundant roles in etioplast differentiation by manipulating the total POR content and the PORA-to-PORB ratio of etiolated Arabidopsis seedlings using antisense and overexpression approaches. POR content correlates closely with PLB formation, the amounts, spectroscopic properties, and photoreduction kinetics of photoactive Pchlide, the ratio of photoactive Pchlide-F655 to non-photoactive Pchl(ide)-F632, and the ratio of divinyl- to monovinyl-Pchl(ide). This last result defines POR as the first endogenous protein factor demonstrated to influence the chemical heterogeneity of Pchl(ide) in angiosperms. It is intriguing that excitation energy transfer between different spectroscopic forms of Pchl(ide) in etiolated cotyledons remains largely independent of POR content. We therefore propose that the PLB contains a minimal structural unit with defined pigment stoichiometries, within which a small amount of non-photoactive Pchl(ide) transfers excitation energy to a large excess of photoactive Pchlide-F655. In addition, our data suggests that POR may bind not only stoichiometric amounts of photoactive Pchlide, but also substoichiometric amounts of non-photoactive Pchl(ide). We conclude that the typical characteristics of etioplasts are closely related to total POR content, but not obviously to the specific presence of PORA or PORB. [less ▲]

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See detailThe Contraceptive Profile of a New Oral Contraceptive with Antimineralocorticoid and Antiandrogenic Effects
Foidart, Jean-Michel ULg

in European Journal of Contraception & Reproductive Health Care : The Official Journal of the European Society of Contraception (2000), 5(Suppl 3), 25-33

Yasmin (Schering AG, Berlin, Germany), a new oral contraceptive containing 30 microg ethinylestradiol combined with 3 mg drospirenone, effectively inhibits ovulation, as demonstrated by measurement of ... [more ▼]

Yasmin (Schering AG, Berlin, Germany), a new oral contraceptive containing 30 microg ethinylestradiol combined with 3 mg drospirenone, effectively inhibits ovulation, as demonstrated by measurement of plasma hormone levels (follicle stimulating hormone, luteinizing hormone, estradiol and progesterone), and echographic evaluation of follicular ripening. Like other low-dose oral contraceptives, the combination of ethinylestradiol and drospirenone markedly limits cervical function, spinnbarkeit and degree of crystallization, resulting in a hostile environment for sperm penetration. Two large, randomized, multicenter, open-label clinical studies have compared the contraceptive efficacy of ethinylestradiol/drospirenone with that of Marvelon, a well-established contraceptive containing 30 microg ethinylestradiol plus 150 microg desogestrel. Both preparations provided effective contraception and good cycle control. There were no negative effects on hemostatic parameters, lipids and carbohydrate metabolism. However, in both studies, ethinylestradiol/drospirenone had a more favorable effect on body weight than ethinylestradiol/desogestrel, with mean body weight remaining lower in the ethinylestradiol/ drospirenone group, the difference between the two preparations being statistically significant. Pre-existing acne and seborrhea were improved by ethinylestradiol/ drospirenone and blood pressure was essentially unchanged. These studies show that ethinylestradiol/drospirenone provides effective oral contraception, excellent cycle control and good tolerability, with effects on body weight and skin condition that are likely to confer a significant beneficial effect on compliance, especially in women with a tendency to gain weight under oral contraceptives due to water retention. [less ▲]

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See detailBone Sialoprotein Mrna and Protein Expression in Human Multiple Myeloma Cell Lines and Patients
Bellahcene, Akeila ULg; Van Riet, I.; de Greef, C. et al

in British Journal of Haematology (2000), 111(4), 1118-21

Bone sialoprotein (BSP) is a glycoprotein essentially found in mineralizing connective tissues. We have recently demonstrated that BSP is ectopically expressed by carcinomas that metastasize to bone with ... [more ▼]

Bone sialoprotein (BSP) is a glycoprotein essentially found in mineralizing connective tissues. We have recently demonstrated that BSP is ectopically expressed by carcinomas that metastasize to bone with high frequency. Multiple myeloma (MM) is characterized by the localization of tumour plasma cells in the bone marrow. In this study, BSP expression was evaluated in human myeloma cell lines and in bone marrow aspirates and one ascites fluid from MM patients. BSP was detectable in conditioned media of MM cell lines. Using FACS analysis and in situ hybridization, we demonstrated that tumour cells from all MM patients and cell lines analysed express BSP at both the protein and the mRNA level. [less ▲]

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See detailStripes Ordering in Self-Stratification Experiments of Binary and Ternary Granular Mixtures
Lecocq, N.; Vandewalle, Nicolas ULg

in Physical Review. E : Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics (2000), 62(6, Pt B), 8241-4

The self-stratification of binary and ternary granular mixtures has been experimentally investigated. Ternary mixtures lead to a particular ordering of the strata which was not accounted for in former ... [more ▼]

The self-stratification of binary and ternary granular mixtures has been experimentally investigated. Ternary mixtures lead to a particular ordering of the strata which was not accounted for in former explanations. Bouncing grains are found to have an important effect on stratum formation. A complementary mechanism for self-stratification of binary and ternary granular mixtures is proposed. [less ▲]

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See detailIonic end-capping of (semi)telechelic polymers by mesogens
Gohy, Jean-François; Sobry, Roger ULg; Van den Bossche, Guy ULg et al

in Polymer International (2000), 49(11), 1293-1301

Two methods have been used to end-cap linear polymer chains at one end or at both ends by a mesogen through ionic bonding. These polymers are designated as liquid-crystalline halato(semi)telechelic ... [more ▼]

Two methods have been used to end-cap linear polymer chains at one end or at both ends by a mesogen through ionic bonding. These polymers are designated as liquid-crystalline halato(semi)telechelic polymers (LC H(S)TPs). The first method relies on the ion exchange reaction between the metal counterion of halato(semi)telechelic polymers and an ionic mesogen. The second method is based on the proton transfer from a sulfonic or carboxylic acid end-group to a tertiary aliphatic amine, this approach being controlled by the relative pKa values of the acidic and basic groups. If the pKa difference is not large enough, strong hydrogen-bonding is observed by Fourier-transform infrared (FTIR) spectroscopy rather than proton transfer. The resulting materials have been characterized by differential scanning calorimetry (DSC), polarized optical microscopy (POM) and small-angle X-ray scattering (SAXS). [less ▲]

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See detailL'électronique au service de la détection des chaleurs.
Hanzen, Christian ULg

in Hebdo Vétérinaire (2000), 32

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See detailConsiderations on delocalized HbA(1c) assays
Bordas-Fonfrede, M.; Selam, J. L.; Goudable, J. et al

in Diabètes & Métabolism (2000), 26(6), 508-512

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See detailA 295-Kda Intermediate Filament-Associated Protein in Radial Glia and Developing Muscle Cells in Vivo and in Vitro
Chanas-Sacre, Grazyna; Thiry, Marc ULg; Pirard, Sandrine et al

in Developmental Dynamics : An Official Publication of the American Association of Anatomists (2000), 219(4), 514-25

The RC2 antibody is frequently used to label mouse radial glial cells in all parts of the nervous system where neuronal migration occurs during embryonic and early postnatal life. The antigen recognized ... [more ▼]

The RC2 antibody is frequently used to label mouse radial glial cells in all parts of the nervous system where neuronal migration occurs during embryonic and early postnatal life. The antigen recognized by this antibody still needs to be identified. We have characterized further its localization in vivo, its expression and subcellular localization in vitro, as well as its molecular nature. Histologic investigations of whole mouse embryos reveal an equally intense expression of RC2 immunostaining in radial glial cells in brain and spinal cord and in skeletal muscle. In glial cells cultures, the RC2 antibody recognizes an epitope located on the glial cytoskeleton and identified as an intermediate filament associated protein (IFAP) at the ultrastructural level. RC2 immunostaining in those cells is strongly dependent on the presence of a serum-derived activity. Serum-removal causes a decrease of the staining while adding serum back to the cells induces reexpression of RC2 immunoreactivity. By Western blotting, we find that in intermediate filament (IF) preparations obtained from cultured cerebellar glia, the RC2 antibody recognizes a 295-kDa protein whose expression is also dependent on the presence of serum in culture medium. In developing muscle cells, RC2 immunostaining is observed from the myoblast stage and disappears after complete myotube fusion. Both in vivo and in vitro, staining is first seen as a loose capping around myoblasts nuclei and progressively concentrates into Z-disks in association with the muscle IF protein desmin. The RC2 antibody also recognizes a 295-kDa protein band in muscle tissue protein extracts. Thus, the RC2 antibody recognizes a developmentally regulated cytoskeletal protein that is expressed, like other previously identified IFAPs, by cells of the glial and myogenic lineages and whose expression in vitro seems to be controlled by a signaling mechanism known to modulate astroglial morphology. [less ▲]

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See detailVirus Neutralizing Antibodies against a Panel of 18 Bvdv Isolates in Calves Vaccinated with Rispoval Rs-Bvd
Hamers, C.; Di Valentin, Emmanuel ULg; Dumont, Chloé ULg et al

in Journal of Veterinary Medicine. B, Infectious Diseases & Veterinary Public Health (2000), 47(10), 721-6

Seven of nine colostrum-deprived calves, free from infection with bovine virus diarrhoea virus (BVDV), were vaccinated with Rispoval RS-BVD on two occasions, 21 days apart, while the other two were kept ... [more ▼]

Seven of nine colostrum-deprived calves, free from infection with bovine virus diarrhoea virus (BVDV), were vaccinated with Rispoval RS-BVD on two occasions, 21 days apart, while the other two were kept as BVDV infection controls. The virus neutralizing (VN) serum antibodies induced by vaccination were tested for their ability to neutralize 18 European BVDV isolates, including laboratory reference strains and recent field isolates, both cytopathic and non-cytopathic biotypes as well as genotypes I and II. The strains were isolated in Belgium, France, Germany and the United Kingdom. While there were large variations in the vaccine-induced VN titres of the individual calves against all the strains, e.g. the titres against Osloss NCP, the European reference strain ranged from 1.7 to 6.7 (1:log2), serum from each animal was capable of neutralizing between nine and all 18 of the strains tested. Nevertheless, from the results of this study, it can be concluded that in colostrum-deprived BVDV seronegative calves, Rispoval RS-BVD can stimulate the production of VN antibodies capable of neutralizing a wide range of antigenically diverse European isolates of BVDV, including genotypes I and II. [less ▲]

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See detailEvaluation de l'efficacité de la lutte chimique contre Helicoverpa armigera sur le cotonnier durant la campagne agricole 1996 au Burkina Faso
Toé, A.M.; Héma, S.A.O.; Schiffers, Bruno ULg

in Etudes et Recherches Sahéliennes (2000), 4-5

ln 1996, the cotton subsector in Burkina Faso experienced a great crisis which was drama-like here and there. An exceptionally high infestation of cotton plants by the main pest, Helicoverpa armigera (a ... [more ▼]

ln 1996, the cotton subsector in Burkina Faso experienced a great crisis which was drama-like here and there. An exceptionally high infestation of cotton plants by the main pest, Helicoverpa armigera (a density of 167n500 worms par hectare) on treated plots whereas the theoretical intervention threshold is ranging from 5,000 to 12,500 Army-worms per hectare could not be controlled by the released insecticides. This year, the infestation intensity was at least sirnilar with the one of the year 1991 in which harvest losses had been estimated at 50,000 tons of seed cotton (NIBOUCHE 1994), i.e. a loss of about 20 billion francs CFA. The aftermath was really heavy for the productucers, SOFITEX and the Burkina state. Four years later, well informed and well-advised experts take into consideration the natural factors and hurnan opcrational factors that are the source of this economie drarna : findings from two independent expert reports produced according to Laboratory Good Pratices (GLP) at the request of civil society on sorne pesticides, highlited concordantly their poor quality (low active ingredient. content, poor quality of formulations). This work, whilst restoring truth in a fair and unbiased way, states the reasons for our past and current failures as weil as the reasons for our future successes. By proposing a new approach to studies on the efficacy of cotton insecticides, tbis work contributes to the seeking of a better phytosanitary protection for cotton in the countries of the sub-region. [less ▲]

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See detailLe syndrome de Gitelman: une cause rare d'hypokaliemie
Brasseur, Edmond ULg; PHILIPS, Jean-Christophe ULg; Rorive, Georges ULg et al

in Revue Médicale de Liège (2000), 55(12), 1037-40

We report a case of hypokaliemia whose origin is a urinary potassium loss associated with syndrome of Gitelman. The syndrome of Gitelman is a rare familiar autosomal recessive nephropathy. We will discuss ... [more ▼]

We report a case of hypokaliemia whose origin is a urinary potassium loss associated with syndrome of Gitelman. The syndrome of Gitelman is a rare familiar autosomal recessive nephropathy. We will discuss the pathophysiology of this syndrome and differential diagnoses. [less ▲]

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See detailSma Circuits Reduce Platelet Consumption and Platelet Factor Release During Cardiac Surgery
Defraigne, Jean-Olivier ULg; Pincemail, Joël ULg; Dekoster, Guy ULg et al

in Annals of Thoracic Surgery (2000), 70(6), 2075-81

BACKGROUND: Platelet count and function are particularly damaged by cardiopulmonary bypass (CPB). This study evaluated the effects of a novel CPB circuit in terms of platelet count and activation, and ... [more ▼]

BACKGROUND: Platelet count and function are particularly damaged by cardiopulmonary bypass (CPB). This study evaluated the effects of a novel CPB circuit in terms of platelet count and activation, and postoperative need for blood products. METHODS: One hundred patients undergoing coronary grafting were randomized in two groups: control group (n = 50) and test group (n = 50, surface modifying additives circuit, SMA group). Blood samples were taken before, during, and after CPB. Postoperative blood loss, number of transfused blood products, and postoperative variables were recorded. RESULTS: The platelet count decreased less in the SMA group compared to the control group (end of CPB: respectively, 165 +/- 9 x 10(3)/mm3 vs 137 +/- 8 x 10(3)/mm3; p < 0.01). This was paralleled by a reduction in beta-thromboglobulin plasma levels in the SMA group. There was a trend to decreased blood loss in the SMA group, but the difference was significant only in patients taking aspirin preoperatively (p < 0.05). In the SMA group nearly 50% less fresh frozen plasma and platelet units were administered (p < 0.01). No operative deaths were observed. CONCLUSIONS: The use of circuits with surface additives is clinically safe, preserves platelet levels, and attenuates platelet activation. This may lead to a reduced need for blood products. [less ▲]

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See detailProtection fongicide intégrée au mode de conduire de la culture. Exemple du blé en Belgique
Bodson, Bernard ULg; Meeùs, Patrick; Moreau, Jean-Marc et al

in Phytoma : La Défense des Végétaux (2000), 533

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See detailRoles of Nuclear Factor-Kappab, P53, and P21/Waf1 in Daunomycin-Induced Cell Cycle Arrest and Apoptosis
Hellin, A. C.; Bentires-Alj, M.; Verlaet, Myriam ULg et al

in Journal of Pharmacology and Experimental Therapeutics (The) (2000), 295(3), 870-8

Daunomycin is a potent inducer of p53 and NF-kappaB transcription factors. It is also able to increase the amount of the p21 cyclin-dependent kinase inhibitor. The human p21 promoter harbors p53 ... [more ▼]

Daunomycin is a potent inducer of p53 and NF-kappaB transcription factors. It is also able to increase the amount of the p21 cyclin-dependent kinase inhibitor. The human p21 promoter harbors p53-responsive elements and an NF-kappaB binding site. [less ▲]

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See detailCytokine Production from Peripheral Whole Blood in Atopic and Nonatopic Asthmatics: Relationship with Blood and Sputum Eosinophilia and Serum Ige Levels
Bettiol, J.; Bartsch, Pierre ULg; Louis, Renaud ULg et al

in Allergy (2000), 55(12), 1134-41

BACKGROUND: The cytokine network is thought to be essential in orchestrating airway inflammation in asthma. Although evidence has accumulated to suggest that atopic asthma is a Th2 disease, much less is ... [more ▼]

BACKGROUND: The cytokine network is thought to be essential in orchestrating airway inflammation in asthma. Although evidence has accumulated to suggest that atopic asthma is a Th2 disease, much less is known about nonatopic asthma. METHODS: We have compared the production of IL-4, IL-6, IFN-gamma, and TNF-alpha from peripheral blood leukocytes between atopic (n=21) and nonatopic (n=22) asthmatics and healthy nonatopic subjects (n=20). Peripheral blood was incubated for 24 h either without stimulus or with LPS or PHA. Cytokines were measured by the immunotrapping technique (Dynamic Immunoassay). RESULTS: When compared to healthy nonatopic subjects, both atopic and nonatopic asthmatics showed increased blood and sputum eosinophilia associated with raised total serum IgE levels. Similarly, both asthma groups displayed spontaneous, endotoxin-induced overproduction of IL-6. Enhanced spontaneous, endotoxin-induced release of IL-4 combined with reduced spontaneous IFN-gamma production was seen only in atopic asthma. In this group of patients, the production of IL-4 was related to the extent of blood and sputum eosinophilia. In nonatopic asthmatics, serum levels of IgE were inversely related to the production of IFN-gamma. CONCLUSIONS: Both atopic and intrinsic asthma display raised blood and airway eosinophilia, raised total serum IgE, and overproduction of IL-6 from peripheral blood. Atopic asthma is also characterized by impaired spontaneous release of IFN-gamma and increased production of IL-4 that correlates with the magnitude of eosinophilic inflammation. [less ▲]

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See detailTolerance to the Foeto-Placental 'Graft': Ten Ways to Support a Child for Nine Months
Thellin, Olivier ULg; Coumans, Bernard ULg; Zorzi, Willy ULg et al

in Current Opinion in Immunology (2000), 12(6), 731-7

Tolerance to the foetal 'allograft' has been extensively studied in the past few years, providing interesting new insights. In addition to a potential role for HLA-G, which has been widely discussed ... [more ▼]

Tolerance to the foetal 'allograft' has been extensively studied in the past few years, providing interesting new insights. In addition to a potential role for HLA-G, which has been widely discussed, there are hypotheses suggesting roles for several other molecules or cells: leukemia inhibitory factor and its receptor; indoleamine 2. 3-dioxygenase; the Th1/Th2 balance; suppressor macrophages; hormones such as progesterone or the placental growth hormone; CD95 and its ligand; and, as recently proposed, annexin II. Tolerance of the foetal allograft is probably the consequence of a wide panel of mechanisms that may or may not be pregnancy-specific, that are of major or secondary importance and that may be interconnected. [less ▲]

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See detailPsychrophilic Enzymes: Revisiting the Thermodynamic Parameters of Activation May Explain Local Flexibility
Lonhienne, T.; Gerday, Charles ULg; Feller, Georges ULg

in Biochimica et Biophysica Acta (2000), 1543(1), 1-10

Basic theoretical and practical aspects of activation parameters are briefly reviewed in the context of cold-adaptation. In order to reduce the error impact inherent to the transition state theory on the ... [more ▼]

Basic theoretical and practical aspects of activation parameters are briefly reviewed in the context of cold-adaptation. In order to reduce the error impact inherent to the transition state theory on the absolute values of the free energy (DeltaG(#)), enthalpy (DeltaH(#)) and entropy (DeltaS(#)) of activation, it is proposed to compare the variation of these parameters between psychrophilic and mesophilic enzymes, namely Delta(DeltaG(#))(p-m), Delta(DeltaH(#))(p-m) and Delta(DeltaS(#))(p-m). Calculation of these parameters from the available literature shows that the main adaptation of psychrophilic enzymes lies in a significant decrease of DeltaH(#), therefore leading to a higher k(cat), especially at low temperatures. Moreover, in all cases including cold-blooded animals, DeltaS(#) exerts an opposite and negative effect on the gain in k(cat). It is argued that the magnitude of this counter-effect of DeltaS(#) can be reduced by keeping some stable domains, while increasing the flexibility of the structures required to improve catalysis at low temperature, as demonstrated in several cold-active enzymes. This enthalpic-entropic balance provides a new approach explaining the two types of conformational stability detected by recent microcalorimetric experiments on psychrophilic enzymes. [less ▲]

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See detailAdsorption of an aqueous mixture of surfactants on silica
Thibaut, Anne; Misselyn-Bauduin, Anne-Marie; Grandjean, Jean ULg et al

in Langmuir (2000), 16(24), 9192-9198

The behavior of mixtures of a nonionic surfactant, pentaethylene glycol monodecyl ether (C10E5), and an anionic surfactant, sodium dodecyl sulfate (SDS), was studied at the water−silica interface. In ... [more ▼]

The behavior of mixtures of a nonionic surfactant, pentaethylene glycol monodecyl ether (C10E5), and an anionic surfactant, sodium dodecyl sulfate (SDS), was studied at the water−silica interface. In contrast to the C10E5 surfactant, which is adsorbed at the silica−water interface at pH 6, the adsorption of the anionic surfactant is not observed. In the presence of SDS, the adsorption of C10E5 is severely restricted as result of the formation of mixed micelles in solution. This behavior is consistent with the adsorption free energy, ΔGads, of C10E5 and the free energy of mixed micellization, ΔGmix.mic, of SDS and C10E5. Flow microcalorimetry (FMC) results showed that the addition of C10E5/SDS mixtures to silica precoated with C10E5 resulted in the release of the preadsorbed nonionic surfactant; the whole phenomenon is exothermic. Combination of calorimetric data (FMC and isothermal titration calorimetry), self-diffusion coefficients, and the regular solution theory led to the conclusion that the main driving force for the C10E5 desorption was the formation of mixed micelles by unimeric SDS and the released nonionic surfactant. [less ▲]

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See detailResistance of Isolated Pulmonary Mitochondria During in Vitro Anoxia/Reoxygenation
Willet, K.; Detry, Olivier ULg; Sluse, Francis ULg

in Biochimica et Biophysica Acta (2000), 1460(2-3), 346-52

The aim of the study was to investigate the effect of in vitro anoxia/reoxygenation on the oxidative phosphorylation of isolated lung mitochondria. Mitochondria were isolated after harvesting from fresh ... [more ▼]

The aim of the study was to investigate the effect of in vitro anoxia/reoxygenation on the oxidative phosphorylation of isolated lung mitochondria. Mitochondria were isolated after harvesting from fresh pig lungs flushed with Euro-Collins solution. Mitochondrial respiratory parameters were determined in isolated mitochondria before anoxia (control), after 5-45 min anoxia followed by 5 min reoxygenation, and after 25 or 40 min of in vitro incubation in order to follow the in vitro aging of mitochondria during respiratory assays. Respiratory parameters measured after anoxia/reoxygenation did not show any oxidative phosphorylation dysfunction, indicating a high resistance of pulmonary mitochondria to in vitro anoxia/reoxygenation (up to 45 min anoxia). These results indicate that mitochondria are not directly responsible of their oxidative phosphorylation damage observed after in vivo ischemia (K. Willet et al., Transplantation 69 (2000) 582) but are a target of others cellular injuries leading to mitochondrial dysfunction in vivo. [less ▲]

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See detailNf-Kappab Activation in Response to Toxical and Therapeutical Agents: Role in Inflammation and Cancer Treatment
Bours, Vincent ULg; Bonizzi, Giuseppina; Bentires-Alj, Mohamed et al

in Toxicology (2000), 153(1-3), 27-38

The NF-kappaB transcription factor is ubiquitously expressed and controls the expression of a large number of genes. Experimental data clearly indicate that NF-kappaB is a major regulator of the ... [more ▼]

The NF-kappaB transcription factor is ubiquitously expressed and controls the expression of a large number of genes. Experimental data clearly indicate that NF-kappaB is a major regulator of the inflammatory reaction by controlling the expression of pro-inflammatory molecules in response to cytokines, oxidative stress and infectious agents. We demonstrated that NF-kappaB activation by IL-1beta follows three distinct cell-specific pathways. Moreover, our studies indicated that in one model of inflammatory diseases, horse recurrent airway obstruction (RAO), the extent of NF-kappaB basal activity correlates with pulmonary dysfunction. Another role of NF-kappaB activity protects cancer cells against apoptosis and could participate in the resistance to cancer treatment. However, we did not observe any increased cytotoxicity after treatment with anticancer drugs or TNF-alpha of cells expressing a NF-kappaB inhibitor. Therefore, we can conclude that the inhibition of apoptosis by NF-kappaB is likely to be cell type and stimulus-dependent. Further studies are required to determine whether NF-kappaB could be a target for anticancer treatments. [less ▲]

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See detailMechanisms of Persistent Nf-Kappa B Activity in the Bronchi of an Animal Model of Asthma
Bureau, Fabrice ULg; Delhalle, Sylvie; Bonizzi, Giuseppina et al

in Journal of Immunology (2000), 165(10), 5822-5830

In most cells trans-activating NF-kappaB induces many inflammatory proteins as well as its own inhibitor, IkappaB-alpha, thus assuring a transient response upon stimulation. However, NF-kappaB-dependent ... [more ▼]

In most cells trans-activating NF-kappaB induces many inflammatory proteins as well as its own inhibitor, IkappaB-alpha, thus assuring a transient response upon stimulation. However, NF-kappaB-dependent inflammatory gene expression is persistent in asthmatic bronchi, even after allergen eviction. In the present report we used bronchial brushing samples (BBSs) from heaves-affected horses (a spontaneous model of asthma) to elucidate the mechanisms by which NF-kappaB activity is maintained in asthmatic airways. NF-kappaB activity was high in granulocytic and nongranulocytic BBS cells. However, NF-kappaB activity highly correlated to granulocyte percentage and was only abrogated after granulocytic death in cultured BBSs. Before granulocytic death, NF-kappaB activity was suppressed by simultaneous addition of neutralizing anti-IL-1beta and anti-TNF-alpha Abs to the medium of cultured BBSs. Surprisingly, IkappaB-beta, whose expression is not regulated by NF-kappaB, unlike IkappaB-alpha, was the most prominent NF-kappaB inhibitor found in BBSs. The amounts of IkappaB-beta were low in BBSs obtained from diseased horses, but drastically increased after addition of the neutralizing anti-IL-1beta and anti-TNF-alpha Abs. These results indicate that sustained NF-kappaB activation in asthmatic bronchi is driven by granulocytes and is mediated by IL-1beta and TNF-alpha. Moreover, an imbalance between high levels of IL-1beta- and TNF-alpha-mediated IkappaB-beta degradation and low levels of IkappaB-beta synthesis is likely to be the mechanism preventing NF-kappaB deactivation in asthmatic airways before granulocytic death. [less ▲]

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See detailPolarization holography reveals the nature of the grating in polymers containing azo-dye
Blanche, Pierre-Alexandre ULg; Lemaire, P. C.; Maertens, Christophe et al

in Optics Communications (2000), 185(1-3), 1-12

To study the origin of reversible holographic recording in three polymers containing the same azo-dye, we have measured the diffraction efficiency and analyzed the gratings characteristics for various ... [more ▼]

To study the origin of reversible holographic recording in three polymers containing the same azo-dye, we have measured the diffraction efficiency and analyzed the gratings characteristics for various writing beams polarizations. The amplitude of the holographic grating, as well as the ratio between index and absorption modulations, have been investigated by gratings shifting. The total amount of diffracted power and the diffraction efficiency versus the reading beam polarization has been measured by non-degenerated four waves mixing. These experiments have revealed that the molecular mechanisms of holographic recording in the studied compounds are different. The photoinduced orientation of the chromophores is predominant for C6-C11-DMNPAA; so, in C11-C6-DMNPAA (DMNPAA: 2,5-dimethyl-4-(p-nitrophenylazo)anisole), the refractive index variation comes from the presence of both trans and cis populations generated by photoisomerization. The behavior of the PVK:DMNPAA is included between these extreme cases since both phenomena act. [less ▲]

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See detailLinear and nonlinear Rayleigh-Bénard-Marangoni instability with surface deformations
Regnier, Vincent; Dauby, Pierre ULg; Lebon, Georgy ULg

in Physics of Fluids (2000), 12

Thermoconvective instabilities in a bilayer liquid-gas system with a deformed interface are investigated. In the first part of the work which is devoted to a linear approach, emphasis is put on the role ... [more ▼]

Thermoconvective instabilities in a bilayer liquid-gas system with a deformed interface are investigated. In the first part of the work which is devoted to a linear approach, emphasis is put on the role of the upper gas layer on the instability phenomenon. The condition to be satisfied by the gas to remain purely conductive is established. The so-called Oberbeck-Boussinesq approximation is discussed and its range of validity is carefully defined. Instead of the classical Rayleigh, Marangoni, crispation, and Galileo numbers, new dimensionless groups are introduced. A critical comparison with several previous works is made. The nonlinear analysis consists in studying the different convective patterns which can appear above the threshold. Particular attention is devoted to the shape of the interface and the so-called ``hybrid'' relief. The amplitude of the deformation is also determined and comparison with experimental data is discussed. [less ▲]

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See detailAn Optical Time Delay Estimate for the Double Gravitational Lens System B1600+434
Burud, I.; Hjorth, J.; Jaunsen, A. O. et al

in Astrophysical Journal (2000), 544

We present optical I-band light curves of the gravitationally lensed double QSO B1600+434 from observations obtained at the Nordic Optical Telescope (NOT) between 1998 April and 1999 November. The ... [more ▼]

We present optical I-band light curves of the gravitationally lensed double QSO B1600+434 from observations obtained at the Nordic Optical Telescope (NOT) between 1998 April and 1999 November. The photometry has been performed by simultaneous deconvolution of all the data frames, involving a numerical lens galaxy model. Four methods have been applied to determine the time delay between the two QSO components, giving a mean estimate of Deltat=51+/-4 days (95% confidence level). This is the fourth optical time delay ever measured. Adopting a Omega=0.3, Lambda=0 universe and using the mass model of Maller et al., this time delay estimate yields a Hubble parameter of H[SUB]0[/SUB]=52[SUP]+14[/SUP][SUB]-8[/SUB] km s[SUP]-1[/SUP] Mpc[SUP]-1[/SUP] (95% confidence level), where the errors include time delay as well as model uncertainties. There are time-dependent offsets between the two (appropriately shifted) light curves that indicate the presence of external variations due to microlensing. Based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. [less ▲]

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See detailThe Old Halo metallicity gradient: the trace of a self-enrichment process
Parmentier, Geneviève ULg; Jehin, Emmanuel ULg; Magain, Pierre ULg et al

in Astronomy and Astrophysics (2000), 363

Based on a model of globular cluster self-enrichment published in a previous paper, we present an explanation for the metallicity gradient observed throughout the galactic Old Halo. Our self-enrichment ... [more ▼]

Based on a model of globular cluster self-enrichment published in a previous paper, we present an explanation for the metallicity gradient observed throughout the galactic Old Halo. Our self-enrichment model is based on the ability of globular cluster progenitor clouds to retain the ejecta of a first generation of Type II Supernovae. The key point is that this ability depends on the pressure exerted on the progenitor cloud by the surrounding protogalactic medium and therefore on the location of the cloud in the protoGalaxy. Since there is no significant (if any) metallicity gradient in the whole halo, we also present a review in favour of a galactic halo partly built via accretions and mergers of satellite systems. Some of them bear their own globular clusters and therefore ``contaminate'' the system of globular clusters formed ``in situ'', namely within the original potential well of the Galaxy. Therefore, the comparison between our self-enrichment model and the observational data should be limited to the genuine galactic globular clusters, the so-called Old Halo group. [less ▲]

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See detailCoordinated monitoring of the eccentric O-star binary Iota Orionis: the X-ray analysis
Pittard, Julian M; Stevens, Ian R; Corcoran, Michael F et al

in Monthly Notices of the Royal Astronomical Society (2000), 319

We analyse two ASCA observations of the highly eccentric O9 III+B1 III binary Iota Orionis obtained at periastron and apastron. Based on the assumption of a strong colliding-wind shock between the stellar ... [more ▼]

We analyse two ASCA observations of the highly eccentric O9 III+B1 III binary Iota Orionis obtained at periastron and apastron. Based on the assumption of a strong colliding-wind shock between the stellar components, we expected to see significant variation in the X-ray emission between these phases. The observations proved otherwise: the X-ray luminosities and spectral distributions were remarkably similar. The only noteworthy feature in the X-ray data was the hint of a proximity effect during periastron passage. Although this `flare' is of relatively low significance, it is supported by the notable proximity effects seen in the optical, and the phasing of the X-ray and optical events is in very good agreement. However, other interpretations are also possible. In view of the degradation of the SIS instrument and source contamination in the GIS data we discuss the accuracy of these results, and also analyse archival ROSAT observations. We investigate why we do not see a clear colliding-wind signature. A simple model shows that the wind attenuation to the expected position of the shock apex is negligible throughout the orbit, which poses the puzzling question of why the expected 1/D variation (i.e. a factor of 7.5) in the intrinsic luminosity is not seen in the data. Two scenarios are proposed: either the colliding-wind emission is unexpectedly weak such that intrinsic shocks in the winds dominate the emission, or, alternatively, the emission observed is colliding-wind emission but in a more complex form than we would naively expect. Complex hydrodynamical models are then analysed. Despite strongly phase-variable emission from the models, both are consistent with the observations. We find that if the mass-loss rates of the stars are low then intrinsic wind shocks could dominate the emission. However, when we assume higher mass-loss rates of the stars, we find that the observed emission could also be consistent with a purely colliding-wind origin. A summary of the strengths and weaknesses of each interpretation is presented. To distinguish between the different models X-ray observations with improved phase coverage will be necessary. [less ▲]

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See detailProduction of Bovine Herpesvirus Type 1-Seronegative Latent Carriers by Administration of a Live-Attenuated Vaccine in Passively Immunized Calves
Lemaire, Mylène; Meyer, Gilles; Baranowski, Eric et al

in Journal of Clinical Microbiology (2000), 38(11), 4233-8

The consequences of the vaccination of neonatal calves with the widely used live-attenuated temperature-sensitive (ts) bovine herpesvirus type 1 (BHV-1) were investigated. The ts strain established acute ... [more ▼]

The consequences of the vaccination of neonatal calves with the widely used live-attenuated temperature-sensitive (ts) bovine herpesvirus type 1 (BHV-1) were investigated. The ts strain established acute and latent infections in all vaccinated calves either with or without passive immunity. Four of seven calves vaccinated under passive immunity became clearly BHV-1 seronegative by different serological tests, as did uninfected control calves after the disappearance of maternal antibodies, and they remained so for long periods. A cell-mediated immune response was detected by a BHV-1 gamma interferon assay, but this test failed to detect the seronegative latent carriers (SNLCs). While they are not detected, SNLCs represent a threat for BHV-1-free herds or countries. This study demonstrates that SNLCs can be easily obtained by inoculation with a live-attenuated BHV-1 under passive immunity and that latent carrier animals without any antibody do exist. Consequently, this situation could represent a good model to experimentally produce SNLCs. [less ▲]

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See detailLa fibromyalgie en l'an 2000
Maquet, Didier ULg; Croisier, Jean-Louis ULg; Crielaard, Jean-Michel ULg

in Revue Médicale de Liège (2000), 55(11), 991-7

Musculoskeletal pain is common in the population. Several pathologies like fibromyalgia (FM), chronic fatigue syndrome (CFS) or spasmophilia are associated with functional myalgia. The etiology of FM ... [more ▼]

Musculoskeletal pain is common in the population. Several pathologies like fibromyalgia (FM), chronic fatigue syndrome (CFS) or spasmophilia are associated with functional myalgia. The etiology of FM remains elusive, but the diagnosis is well established. The criteria for the classification are widespread pain combined with tenderness at 11 or more of the 18 specific tender points sites. The prevalence is 2% in the general population. This article reviews recent data on the pathophysiology and treatment of FM. [less ▲]

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See detailPropriété intellectuelle : vers une exception à l’épuisement communautaire?
Munoz, Rodolphe ULg

in Journal des Tribunaux Droit Européen (2000), 73

La théorie de l’épuisement empêche une entreprise de s’opposer à la commercialisation d’un produit qui a été écoulé sur un autre marché. L’épuisement est dit "communautaire" ou régional: la protection ne ... [more ▼]

La théorie de l’épuisement empêche une entreprise de s’opposer à la commercialisation d’un produit qui a été écoulé sur un autre marché. L’épuisement est dit "communautaire" ou régional: la protection ne peut être invoquée dans un Etat membre lorsque le produit a déjà été mis sur le marché dans un autre pays de la Communauté. La jurisprudence analysée dans cet article indique que l’épuisement pourrait devenir mondial. Aucune firme ne pourrait alors empêcher l’écoulement d’un produit commercialisé dans un pays tiers. Les vendeurs pourraient écouler dans la Communauté des produits achetés moins cher à l’étranger. Cela serait particulièrement intéressant pour les produits électroniques, qui sont traditionnellement chers en Europe. Le processus entraînerait, à moyen terme, une diminution des prix sur le continent européen. [less ▲]

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See detailMicro-adénomes à prolactine : le traitement par cabergoline
Beckers, Albert ULg; Valdes Socin, Hernan Gonzalo ULg

in Médecine Thérapeutique Endocrinologie (2000), 2(6), 496-500

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See detailL'image du mois. Histiocytome fibreux malin
Delanaye, Pierre ULg; Heymans, Olivier; Boverie, Jacques ULg

in Revue Médicale de Liège (2000), 55(11), 969

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See detailReactive compatibilization of SAN/EPR blends: Effect of rubber content and reactivity of the SAN functional groups
Pagnoulle, Christophe; Martin, Philippe; Jérôme, Robert ULg

in Macromolecular Chemistry and Physics (2000), 201(16), 2181-2194

SAN containing 20 wt.-% reactive SAN-X was melt blended with EPDM containing 50 wt.-% maleic anhydride EPR grafted chains (EP-g-MA). The rubber content was changed from 15 to 80 wt.-%, and 2 types of ... [more ▼]

SAN containing 20 wt.-% reactive SAN-X was melt blended with EPDM containing 50 wt.-% maleic anhydride EPR grafted chains (EP-g-MA). The rubber content was changed from 15 to 80 wt.-%, and 2 types of reactive groups (X) were attached to SAN (0.028 mol X/ wt.-%), i. e. primary amines and carbamates which are primary amine precursors at the processing temperature. Phase morphology, tensile properties and impact strength depend not only on the rubber content but also on the relative reactivity of the amine and the carbamate groups towards maleic anhydride, in a strong dependence on the reaction rate and the reaction completeness. The dispersion mechanism has been discussed, including formation of sub-inclusions. Dependence of the impact resistance on the rubber phase content for non-reactive blends (□) and blends modified by SAN-NH2 (;) and SAN-carb (o), respectively. [less ▲]

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See detailComment j'explore ... une bouche brulante
Claessens, N.; Pierard-Franchimont, Claudine ULg; Pierard, Gérald ULg

in Revue Médicale de Liège (2000), 55(11), 1011-4

Burning mouth is a symptom typical for the oral mucosa. In contrast, pruritus is absent at this site. The situation which is the reverse on the skin can be explained by microanatomical differences in the ... [more ▼]

Burning mouth is a symptom typical for the oral mucosa. In contrast, pruritus is absent at this site. The situation which is the reverse on the skin can be explained by microanatomical differences in the sensorial innervation and by a different balance between neuromediators. Burning mouth sensation calls for the search of a series of diseases. However, it is most often a monosymptomatic expression of a minimal lichenoid stomatitis. [less ▲]

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See detailDifferences in Experimental Virulence of Bovine Viral Diarrhoea Viral Strains Isolated from Haemorrhagic Syndromes
Hamers, C.; Couvreur, B.; Dehan, Pierre ULg et al

in Veterinary Journal (2000), 160(3), 250-8

In the late 1980s, a new hypervirulent and epidemic form of bovine viral diarrhoea virus (BVDV) infection appeared in North America. A similar but sporadic syndrome was later reported in Europe. To ... [more ▼]

In the late 1980s, a new hypervirulent and epidemic form of bovine viral diarrhoea virus (BVDV) infection appeared in North America. A similar but sporadic syndrome was later reported in Europe. To compare the pathogenic characters of the North American and European hypervirulent strains, we inoculated BVDV naive calves with BVDV strains isolated from haemorrhagic syndromes originating in Belgium, France and the USA. The experimental procedure comprised daily clinical examination and measurement of blood and virological parameters.The American BVD890/256 strain induced severe thrombocytopaenia, profuse diarrhoea and pneumonia in all calves, indicating that hypervirulent BVDV could be the primary infectious agent of pneumonia. Interestingly, a strong correlation was observed between the intense viraemia and a decreased platelet count. None of the European strains tested induced significant pathological signs, although isolated from cases presenting haemorrhagic syndrome. [less ▲]

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See detailMMP-2 and MMP-9-Linked Gelatinolytic Activity in the Sputum from Patients with Asthma and Chronic Obstructive Pulmonary Disease
Cataldo, Didier ULg; Munaut, Carine ULg; Noël, Agnès ULg et al

in International Archives of Allergy & Immunology (2000), 123(3), 259-67

BACKGROUND: The course of asthma and chronic obstructive pulmonary disease (COPD) is associated with bronchial morphological changes. Metalloproteinases are thought to play a role in these structural ... [more ▼]

BACKGROUND: The course of asthma and chronic obstructive pulmonary disease (COPD) is associated with bronchial morphological changes. Metalloproteinases are thought to play a role in these structural changes. METHODS: We studied the gelatinolytic activity present in the induced sputum from 20 patients with asthma, 20 with COPD and 19 healthy controls. The assessment of gelatinolytic activity was performed by quantitative zymography, and gelatinolytic species were identified by Western blot analysis. Tissue inhibitor of metalloproteinase-1 (TIMP-1) was detected by reverse zymography and ELISA. RESULTS: From zymography, we found significantly higher gelatinolytic activity linked to pro-matrix metalloproteinase-9 (pro-MMP-9) in the sputum from asthmatics (p < 0.0001) and COPD patients (p < 0.0001) compared to the control group. Furthermore, the activated form of MMP-9 (85 kD) was found in the sputum from 60% of asthmatics and 85% of COPD patients, but was absent in that of control subjects (p < 0.0001). Importantly, although less frequently detectable than pro-MMP-9, pro- MMP-2 (72 kD) was found more frequently in asthmatics (50%) than in control subjects (5%) (p < 0. 005). We also described two unusual gelatinolytic species of 45 and 120 kD and showed that they derived from MMP-9 according to their ability to bind gelatin and anti-MMP-9 antibody. Levels of TIMP-1 were higher in asthmatics (p < 0.05) and COPD patients (p < 0.05) than in controls. CONCLUSION: Asthmatics and COPD patients display an increased gelatinolytic activity linked to MMP-2 and MMP-9 and higher levels of TIMP-1 in their sputum. [less ▲]

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See detailThe Dppa Gene of Bacillus Subtilis Encodes a New D-Aminopeptidase
Cheggour, Abdelatif; Fanuel, Laurence; Duez, Colette ULg et al

in Molecular Microbiology (2000), 38(3), 504-13

Different strains of Bacillus were screened for their ability to hydrolyse D-alanyl-p-nitroanilide. Activity was detected in Bacillus pumilus, Bacillus brevis, Bacillus licheniformis 749I and Bacillus ... [more ▼]

Different strains of Bacillus were screened for their ability to hydrolyse D-alanyl-p-nitroanilide. Activity was detected in Bacillus pumilus, Bacillus brevis, Bacillus licheniformis 749I and Bacillus subtilis 168. The last strain was the best producer and was selected for the production and purification of the enzyme. The determination of the N-terminal sequence identified the enzyme as the product of the dppA gene (previously named dciAA) belonging to the dipeptide ABC transport (dpp) operon expressed early during sporulation. Open reading frames (ORFs) encoding putative related proteins were found in the genomes of a variety of Archaea and both sporulating and non-sporulating bacteria. The enzyme behaves as a D-aminopeptidase and represents the prototype of a new peptidase family. Among the tested substrates, the highest activities were found with D-Ala-D-Ala and D-Ala-Gly-Gly. The active enzyme behaves as an octamer of identical 30 kDa subunits. It exhibits a broad pH optimum, extending between pH 9 and 11. It is reversibly inhibited in the presence of Zn2+ chelators, and the sequence comparisons highlight the conservation of potential Zn-binding residues. As it has been shown by others that null mutations in the dpp operon do not inhibit spore formation, the physiological role of DppA is probably an adaptation to nutrient deficiency. [less ▲]

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See detailComment je traite ... le myelome multiple refractaire par thalidomide
Scerbo, F.; Matus, G.; Sautois, Brieuc ULg et al

in Revue Médicale de Liège (2000), 55(11), 970-3

Despite the use of high-dose chemotherapy with autologous hematopoietic stem cell transplantation, multiple myeloma remains largely uncurable. Indeed complete remission rate is about 50% and median ... [more ▼]

Despite the use of high-dose chemotherapy with autologous hematopoietic stem cell transplantation, multiple myeloma remains largely uncurable. Indeed complete remission rate is about 50% and median survival reaches 5 years without plateau. Recently thalidomide has been identified as a promising agent. We report the clinical story of 2 patients with refractory myeloma that we treated successfully with thalidomide. [less ▲]

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See detailIn Vitro Study of the Antioxidant Properties of Nimesulide and 4-Oh Nimesulide: Effects on Hrp- and Luminol-Dependent Chemiluminescence Produced by Human Chondrocytes
Zheng, S. X.; Mouithys-Mickalad, Ange ULg; Deby-Dupont, G. P. et al

in Osteoarthritis and Cartilage (2000), 8(6), 419-25

OBJECTIVES: Reactive oxygen species (ROS) are now recognized to play an important role in the pathogenesis of rheumatic diseases and constitute an interesting therapeutic target for drugs. This in vitro ... [more ▼]

OBJECTIVES: Reactive oxygen species (ROS) are now recognized to play an important role in the pathogenesis of rheumatic diseases and constitute an interesting therapeutic target for drugs. This in vitro study was designed to evaluate the antioxidant properties of nimesulide (NIM), a nonsteroidal antiinflammatory drug of the sulfonanilide class, and its main metabolite 4-OH nimesulide (4-OHNIM). METHODS: The scavenging effects of NIM and 4-OH NIM on hydroxyl radical ((.)OH) and superoxide anions (O(minusd)(2)) were investigated by electron spin resonance (ESR), using 5, 5-dimethylpyrroline-N-oxide (DMPO) as the spin trap agent. The quenching properties of these drugs on hypochlorite anion was studied by luminol enhanced chemiluminescence. Finally, the effects of NIM and 4-OHNIM on the reactive oxygen species production by human articular chondrocytes were recorded by HRP and luminol-enhanced chemiluminescence. RESULTS: By this method it has been demonstrated that NIM and 4-OHNIM, at concentrations ranging from 10 to 100 microM, are potent scavengers of(.)OH whereas only 4-OHNIM was capable to scavenge O(minusd)(2). Chemiluminescence generated by HOCl was also significantly and dose-dependently inhibited by both NIM and 4-OHNIM. Nevertheless, at each concentration tested, the inhibitory effect of 4-OHNIM was significantly more marked, even at the highest concentration (100 microM). Furthermore, when chondrocytes were pre-incubated for 48-96 h with NIM or 4-OHNIM, the luminol- and HRP-dependent CL produced by the cells was significantly inhibited in a dose-dependent manner. CONCLUSIONS: NIM and 4-OHNIM may protect cartilage against oxidative stress, not only by scavenging ROS but also by inhibiting their production by chondrocytes. [less ▲]

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See detailHeavy Metals Contamination and Body Condition of Wintering Guillemots (Uria Aalge) at the Belgian Coast from 1993 to 1998
Debacker, Virginie ULg; Jauniaux, Thierry ULg; Coignoul, Freddy ULg et al

in Environmental Research (2000), A84(3), 310-317

A sample of 166 common guillemots (Uria aalge) recovered from Belgian beaches during five wintering seasons, from 1993-1994 to 1997-1998, were examined. At necropsy, postmortem examination including body ... [more ▼]

A sample of 166 common guillemots (Uria aalge) recovered from Belgian beaches during five wintering seasons, from 1993-1994 to 1997-1998, were examined. At necropsy, postmortem examination including body mass, fat reserves, presence or not of intestinal contents, eventual status of oiling, and pathological changes (cachexia, acute hemorrhagic gastroenteropathy (GEAH)) was attributed to each individual. Mild to severe cachexia, a pathology characterized by moderate to severe atrophy of the pectoral muscle as well as reduced amounts or absence of subcutaneous and/or abdominal fat, was observed for most specimens (85.8%). Heavy metal analyses (Cu, Zn, Fe, Cd, Ni, Cr, and Pb) of the tissues (typically liver, kidney, and pectoral muscle) were performed, and total lipids were determined (liver and pectoral muscle). The guillemots collected at the Belgian coast exhibited higher Cu and Zn concentrations compared to individuals collected in more preserved areas of the North Sea such as the northern colonies. A general decrease of their total body mass as well as liver, kidney, and pectoral muscle mass was associated to increasing cachexia severity. Moreover, significantly increasing heavy metal levels (Cu and Zn) in the tissues as well as depleted muscle lipid contents were observed parallel to increasing cachexia severity. On the contrary the organs' total metal burden barely correlates to this status. These observations tend to indicate a general redistribution of heavy metals within the organs as a result of prolonged starvation and protein catabolism (cachectic status). Such a redistribution could well be an additional stress to birds already experiencing stressfull conditions (starvation, oiling). [less ▲]

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See detailLe cas clinique du mois. Fusariose disseminee chez un patient immunodeprime
Quatresooz, Pascale ULg; Meiers, I.; Arrese, J. E. et al

in Revue Médicale de Liège (2000), 55(11), 974-6

Fusarium spp are ubiquitous soil saprophytes and occasional plant pathogens. Fusariosis in humans is usually limited to superficial mycoses. We report the case of a disseminated fungal infection due to ... [more ▼]

Fusarium spp are ubiquitous soil saprophytes and occasional plant pathogens. Fusariosis in humans is usually limited to superficial mycoses. We report the case of a disseminated fungal infection due to Fusarium spp in an immunosuppressed patient suffering from acute lymphoblastic leukemia. This report and review of the recent literature suggest that Fusarium spp are emerging fungal pathogens in immunosuppressed patients. [less ▲]

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See detailLes hyperparathyroidies primaires: étiologies, diagnostic et traitement.
Janssens, L.; Verbeke, V.; Petrossians, Patrick ULg et al

in Revue Médicale de Liège (2000), 55(11), 977-985

L'hyperparathyroïdie primaire est une maladie trop souvent méconnue. Son incidence est estimée à 28/100.000, soit environ 2.800 nouveaux cas par an en Belgique. La fréquence de l'hyperparathyroïdie ... [more ▼]

L'hyperparathyroïdie primaire est une maladie trop souvent méconnue. Son incidence est estimée à 28/100.000, soit environ 2.800 nouveaux cas par an en Belgique. La fréquence de l'hyperparathyroïdie augmente avec l'âge. En effet, 50 % des cas sont rencontrés après l'âge de 70 ans et 3 à 4 % des femmes au-delà de 70 ans sont touchées par l'affection. Cette affection peut être sporadique ou survenir dans un cadre étiologique plus complexe tel que les polyendocrinopathies ou la neurofibromatose. L'attention vers ce diagnostic doit être attirée par une symptomatologie, souvent bâtarde, de fatigue (parfois isolée), de polyurie, de polydipsie, d'hypertension artérielle ou la présence de lithiases rénales. Lorsque le diagnostic d'hyperparathyroïdie est renteu, il convient de localiser la ou les glande(s) pathologique(s) et de définir le contexte étiologique qui pourra déterminer le choix thérapeutique le plus approprié. Une étude biologique simple sera réalisée devant toute suspicion d'hyperparathyroïdie. Dans certains cas, le diagnostic sera aidé par la réalisation d'un test de surcharge calcique qui peut permettre de confirmer l'hyperparathyroïdie et d'apprécier son degré d'autonomisation. [less ▲]

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See detailLes fibroses pulmonaires idiopathiques: nouvelle classification histopathologique et aspects cliniques
Blaise, Pierre ULg; Louis, Renaud ULg; Bartsch, Pierre ULg

in Revue Médicale de Liège (2000), 55(11), 986-90

Idiopathic pulmonary fibrosis (IPF) comprises different interstitial lung diseases of unknown origin. They are classified into four groups based on pathologic criteria: UIP, DIP, AIP and NSIP. This ... [more ▼]

Idiopathic pulmonary fibrosis (IPF) comprises different interstitial lung diseases of unknown origin. They are classified into four groups based on pathologic criteria: UIP, DIP, AIP and NSIP. This classification helps in terms of prognosis and treatment. In addition to history, physical examination and common investigations (chest X ray, pulmonary function testing), a bronchoalveolar lavage (BAL), a high-resolution CT scan and ideally a open-lung biopsy are needed to establish a precise diagnosis. The patients are usually treated by immunosuppressive agents, and mainly by corticoids. However, in UIP, lung transplantation is the only way to improve survival. [less ▲]

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See detailDetermination of the Enantiomers of 3-Tert.-Butylamino-1,2-Propanediol by High-Performance Liquid Chromatography Using Mass Spectrometric Detection
Toussaint, B.; Streel, B.; Ceccato, Attilio ULg et al

in Journal of Chromatography. A (2000), 896(1-2), 201-7

The chiral synthesis of beta-blockers such as (S)-timolol requires a sensitive analytical method for the enantioseparation of its intermediate, 3-tert.-butylamino-1,2-propanediol, in the ng/ml range. The ... [more ▼]

The chiral synthesis of beta-blockers such as (S)-timolol requires a sensitive analytical method for the enantioseparation of its intermediate, 3-tert.-butylamino-1,2-propanediol, in the ng/ml range. The method developed is based on on-line normal-phase LC-MS-MS using a chiral stationary phase and an atmospheric pressure chemical ionization (APCI) interface. The MS detection of 3-tert.-butylamino-1,2-propanediol was first optimized with a pneumatically-assisted electrospray interface (ionspray). The APCI interface was then selected for LC-MS-MS because of the incompatibility of electrospray with n-hexane. The method was validated for both enantiomers in the 25-500 ng/ml concentration range. [less ▲]

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See detailQuantitative Analysis of N-Acetylcysteine and Its Pharmacopeial Impurities in a Pharmaceutical Formulation by Liquid Chromatography-Uv Detection-Mass Spectrometry
Toussaint, B.; Pitti, C.; Streel, B. et al

in Journal of Chromatography. A (2000), 896(1-2), 191-9

A new method for the simultaneous determination of N-acetylcysteine and its pharmacopeial impurities, cysteine, cystine, N,N'-diacetylcystine and N,S-diacetylcysteine in an effervescent tablet has been ... [more ▼]

A new method for the simultaneous determination of N-acetylcysteine and its pharmacopeial impurities, cysteine, cystine, N,N'-diacetylcystine and N,S-diacetylcysteine in an effervescent tablet has been developed. The method is based on on-line LC-UV-MS using a pneumatically-assisted electrospray interface (ionspray). The stability of the thiol moieties of the analytes was ensured by the acidic pH of the LC mobile phase. Quantitation of N-acetylcysteine was performed with UV detection to avoid ion-source overloading effect due to its higher concentration, whereas the impurities could be easily separated and quantified in MS. The method was validated in terms of stability, linearity, precision and accuracy. [less ▲]

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See detailGene activation by varicella-zoster virus IE4 protein requires its dimerization and involves both the arginine-rich sequence, the central part, and the carboxyl-terminal cysteine-rich region
Baudoux, Laurence; Defechereux, Patricia; Rentier, Bernard ULg et al

in Journal of Biological Chemistry (2000), 275(42), 32822-32831

Varicella-zoster virus (VZV) open reading frame 4-encoded protein (IE4) possesses transactivating properties for VZV genes as well as for those of heterologous viruses. Since most transcription factors ... [more ▼]

Varicella-zoster virus (VZV) open reading frame 4-encoded protein (IE4) possesses transactivating properties for VZV genes as well as for those of heterologous viruses. Since most transcription factors act as dimers, IE4 dimerization was studied using the mammalian two-hybrid system. Introduction of mutations in the IE4 open reading frame demonstrated that both the central region and the carboxyl-terminal cysteine-rich domain were important for efficient dimerization. Within the carboxyl-terminal domain, substitution of amino acids encompassing residues 443-447 totally abolished dimerization. Gene activation by IE4 was studied by transient transfection with an IE4 expression plasmid and a reporter gene under the control of either the human immunodeficiency virus, type 1, long terminal repeat or the VZV thymidine kinase promoter. Regions of IE4 important for dimerization were also shown to be crucial for transactivation. In addition, the arginine-rich domains Rb and Re of the amino-terminal region were also demonstrated to be important for transactivation, whereas the Ra domain as well as an acidic and bZIP-containing regions were shown to be dispensable for gene transactivation. A nucleocytoplasmic shuttling of IE4 has also been characterized, involving a nuclear localization signal identified within the Rb domain and a nuclear export mechanism partially depending on Crm-1. [less ▲]

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See detailFree tropospheric CO, C2H6, and HCN above central Europe: Recent measurements from the Jungfraujoch station including the detection of elevated columns during 1998
Rinsland, C. P.; Mahieu, Emmanuel ULg; Zander, Rodolphe ULg et al

in Journal of Geophysical Research. Atmospheres (2000), 105(D19), 24235-24249

Time series of free tropospheric carbon monoxide (CO), ethane (C2H6), and hydrogen cyanide (HCN) column abundances have been derived from observations at the International Scientific Station of the ... [more ▼]

Time series of free tropospheric carbon monoxide (CO), ethane (C2H6), and hydrogen cyanide (HCN) column abundances have been derived from observations at the International Scientific Station of the Jungfraujoch (ISSJ) at 3.58-km altitude in the Swiss Alps (latitude 46.55 degreesN, 7.98 degreesE longitude). The free troposphere was assumed to extend from 3.58 to 11 km altitude, and the related columns were derived for all three molecules from high spectral resolution infrared solar spectra recorded between January 1995 and October 1999. The three molecules show distinct seasonal cycles with maxima during winter for CO and C2H6, and during spring for HCN. These seasonal changes are superimposed on interannual variations. The tropospheric columns of all three molecules were elevated during 1998. Increases were most pronounced for HCN with enhanced values throughout the year, up to a factor of 2 in January 1998 when compared to averages of the other years. The increased tropospheric columns coincide with the period of widespread wildfires during the strong El Nino warm phase of 1997-1998. The emission enhancements above ISSJ are less pronounced, and they peaked after the increases measured above Mauna Loa (19.55 degreesN, 155.6 degreesW). Tropospheric trends for CO, C2H6, and HCN of (2.40 +/- 0.49), (0.47 +/- 0.64), and (7.00 +/- 1.61)% yr(-1)(1 sigma) were derived for January 1995 to October 1999. However, if 1998 measurements are excluded from the fit, CO and HCN trends that are not statistically significant, and a statistically significant decrease in the C2H6 tropospheric column, are inferred. Comparisons of the infrared CO columns with CO in situ surface measurements suggest that the CO free tropospheric vertical Volume mixing ratio profile generally decreases with altitude throughout the year. [less ▲]

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See detailModeled and empirical approaches for retrieving columnar water vapor from solar transmittance measurements in the 0.72, 0.82, and 0.94 μm absorption bands
Ingold, T.; Schmid, B.; Mätzler, C. et al

in Journal of Geophysical Research (2000), 105(D19), 2432724343

A Sun photometer (18 channels between 300 and 1024 nm) has been used for measuring the columnar content of atmospheric water vapor (CWV) by solar transmittance measurements in absorption bands with ... [more ▼]

A Sun photometer (18 channels between 300 and 1024 nm) has been used for measuring the columnar content of atmospheric water vapor (CWV) by solar transmittance measurements in absorption bands with channels centered at 719, 817, and 946 nm. The observable is the band-weighted transmittance function defined by the spectral absorption of water vapor and the spectral features of solar irradiance and system response. The transmittance function is approximated by a three-parameter model. Its parameters are determined from MODTRAN and LBLRTM simulations or empirical approaches using CWV data of a dual-channel microwave radiometer (MWR) or a Fourier transform spectrometer (FTS). Data acquired over a 2-year period during 1996–1998 at two different sites in Switzerland, Bern (560 m above sea level (asl)) and Jungfraujoch (3580 m asl) were compared to MWR, radiosonde (RS), and FTS retrievals. At the low-altitude station with an average CWV amount of 15 mm the LBLRTM approach (based on recently corrected line intensities) leads to negligible biases at 719 and 946 nm if compared to an average of MWR, RS, and GPS retrievals. However, at 817 nm an overestimate of 2.7 to 4.3 mm (18–29%) remains. At the high-altitude station with an average CWV amount of 1.4 mm the LBLRTM approaches overestimate the CWV by 1.0, 1.4, and 0.1 mm (58, 76, and 3%) at 719, 817, and 946 nm, compared to the FTS instrument. At the low-altitude station, CWV estimates, based on empirical approaches, agree with the MWR within 0.4 mm (2.5% of the mean); at the high-altitude site with a factor of 10 less water vapor the agreement of the SPM with the FTS is 0.0 to 0.2 mm (1 to 9% of the mean CWV there). Sensitivity analyses show that for the conditions met at the two stations with CWV ranging from 0.2 to 30 mm, the retrieval errors are smallest if the 946 nm channel is used. [less ▲]

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See detailNuclear Factor-Kappa B, Cancer, and Apoptosis
Bours, Vincent ULg; Bentires-Alj, M.; Hellin, A. C. et al

in Biochemical Pharmacology (2000), 60(8), 1085-9

The role of nuclear factor (NF)-kappa B in the regulation of apoptosis in normal and cancer cells has been extensively studied in recent years. Constitutive NF-kappa B activity in B lymphocytes as well as ... [more ▼]

The role of nuclear factor (NF)-kappa B in the regulation of apoptosis in normal and cancer cells has been extensively studied in recent years. Constitutive NF-kappa B activity in B lymphocytes as well as in Hodgkin's disease and breast cancer cells protects these cells against apoptosis. It has also been reported that NF-kappa B activation by tumor necrosis factor (TNF)-alpha, chemotherapeutic drugs, or ionizing radiations can protect several cell types against apoptosis, suggesting that NF-kappa B could participate in resistance to cancer treatment. These observations were explained by the regulation of antiapoptotic gene expression by NF-kappa B. However, in our experience, inhibition of NF-kappa B activity in several cancer cell lines has a very variable effect on cell mortality, depending on the cell type, the stimulus, and the level of NF-kappa B inhibition. Moreover, in some experimental systems, NF-kappa B activation is required for the onset of apoptosis. Therefore, it is likely that the NF-kappa B antiapoptotic role in response to chemotherapy is cell type- and signal-dependent and that the level of NF-kappa B inhibition is important. These issues will have to be carefully investigated before considering NF-kappa B as a target for genetic or pharmacological anticancer therapies. [less ▲]

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See detailL'influence des réglementations d'ordre public sur la validité des contrats
Delnoy, Michel ULg

in Immobilier (2000), 17

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See detailReactivity of functional SAN toward coreactive EPR-g-MA at planar interface
Pagnoulle, Christophe; Moussaif, Noureddine; Riga, Joseph et al

in Journal of Polymer Science. Part A, Polymer Chemistry (2000), 38(19), 3682-3689

The grafting kinetics of reactive poly(styrene-co-acrylonitrile) (SAN) onto EPR-g-MA was studied under isothermal conditions, at the planar interface of an SAN/ethylene-propylene rubber (EPR) bilayer film ... [more ▼]

The grafting kinetics of reactive poly(styrene-co-acrylonitrile) (SAN) onto EPR-g-MA was studied under isothermal conditions, at the planar interface of an SAN/ethylene-propylene rubber (EPR) bilayer film in relation to the type of reactive groups, NH2 versus carbamate (which is an amine precursor), attached to SAN. The amount of SAN chemically bound to EPR chains at the interface was estimated by selectively washing off the unreacted SAN chains before X-ray photon spectroscopic analysis of the released surface. It is clear that the mutual reactivity of the reactive groups, i.e., the NH2-MA pair versus the carbamate-MA pair, has a decisive effect on the amount of SAN that reacts with EPR-g-MA at the interface. In case of SAN-carb, the grafting reaction is controlled by the thermolysis of the carbamate groups into primary amines. [less ▲]

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See detailNon-invasive approach of motor unit recording during muscle contractions in humans
Disselhorst-Klug, C.; Bahm, J.; RAMAEKERS, Vincent ULg et al

in European Journal of Applied Physiology (2000), 83(2-3), 144-150

Information about the structural and functional characteristics of the motor unit (MU) is highly relevant for the diagnosis of neuromuscular disorders. Electromyography (EMG) is a suitable method for ... [more ▼]

Information about the structural and functional characteristics of the motor unit (MU) is highly relevant for the diagnosis of neuromuscular disorders. Electromyography (EMG) is a suitable method for obtaining the information needed. The problem is the separation of the activity of one MU from others which are simultaneously active. Such investigations of single MU activity have commonly used invasive methods, e.g. employing a needle or a wire. Conventional surface-EMG methods have limited resolution and detect, at high contraction levels, multiple MU superimposed one on the other. The separation of the activity of a single MU can be achieved in a non-invasive way when highly specialised acquisition techniques are used. One approach, called high spatial resolution EMG (HSR-EMG), is based on the use of multi-electrode arrays in combination with a two-dimensional Laplace filter. The HSR-EMG permits the completely non-invasive detection of single MU activity even during maximal voluntary contractions. First applications have shown that the method provides a deeper insight into the functional and structural characteristics of the MU. In this paper the application of HSR-EMG to the diagnosis of neuro-muscular disorders will be presented, and the latest results will be given of its application in the evaluation of treatment of patients with plexus lesion. [less ▲]

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See detailObésité et hypertension artérielle: de la physiopathologie au traitement
Geronooz, Isabelle; Krzesinski, Jean-Marie ULg

in Revue Médicale de Liège (2000), 55(10), 921-928

Obesity constitutes a problem of major concern in our industrialized countries. Overweight is frequently associated with hypertension (50% of hypertensive subjects are obese and the prevalence of ... [more ▼]

Obesity constitutes a problem of major concern in our industrialized countries. Overweight is frequently associated with hypertension (50% of hypertensive subjects are obese and the prevalence of hypertension in obese patients is twice that of the normal population). Both pathologies are major cardiovascular risk factors. This review aims at a better understanding of the relationship between hypertension and overweight and at giving to the clinicians simple and consistent guidelines to treat these two medical entities. [less ▲]

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See detailLack of Association between Adult Asthma and the Tumour Necrosis Factor Alpha-308 Polymorphism Gene
Louis, Renaud ULg; Leyder, E.; Malaise, Michel ULg et al

in European Respiratory Journal (2000), 16(4), 604-8

Tumour necrosis factor (TNF)alpha is a cytokine endowed with potent inflammatory properties that may contribute to airway inflammation in asthma. It has previously been shown that the single base pair ... [more ▼]

Tumour necrosis factor (TNF)alpha is a cytokine endowed with potent inflammatory properties that may contribute to airway inflammation in asthma. It has previously been shown that the single base pair polymorphism-308 (G to A substitution) in the promoter of TNFalpha gene results in enhanced cytokine secretion. Whether this polymorphism is associated with the presence of phenotypic expression of asthma is questioned. In this study the relative frequency of TNF1 and TNF2 alleles in a population of adult healthy subjects (n=98) and adult Caucasian asthmatics (n=95) was compared taking into account their disease severity, atopic status and their smoking habit. For the whole group of asthma the genotype frequency for 1/1, 1/2, 2/2 were 67%, 33% and 0%, respectively, and not significantly different from those found in the control group that reached 70%, 28% and 2% respectively (p>0.05). The allele frequencies in asthma were 86% and 14% for TNF1 and TNF2 respectively while the corresponding figures were 85% and 15% in the control group (p>0.05). Furthermore, subdividing asthmatics into severe forced expiratory volume in one second <60% pred), atopic or smoking patients did not show any significant association with this TNFalpha polymorphism. To conclude the polymorphism -308 in the promoter of the TNFalpha gene does not confer a susceptibility to develop asthma nor to grade its severity. [less ▲]

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See detailApplication of a Mixed Normal Mixture Model for the Estimation of Mastitis-Related Parameters
Detilleux, Johann ULg; Leroy, P. L.

in Journal of Dairy Science (2000), 83(10), 2341-9

The current methodology for estimating genetic parameters for SCC (SCS) does not account for the difference in SCS between healthy cows and cows with an intramammary infection (IMI). We propose a two ... [more ▼]

The current methodology for estimating genetic parameters for SCC (SCS) does not account for the difference in SCS between healthy cows and cows with an intramammary infection (IMI). We propose a two-component finite mixed normal mixture model to estimate IMI prevalence, separate SCS subpopulation means, individual posterior probabilities of IMI, and SCS variance components. The theory is presented and the expectation-conditional maximization algorithm is utilized to compute maximum likelihood estimates. The methodology is illustrated on two simulated data sets based on the current knowledge of SCS parameters. Maximum likelihood estimates of IMI prevalence and SCS subpopulation means were close to simulated values, except for the estimate of IMI prevalence when both subpopulations were almost confounded. Individual posterior probabilities of IMI were always higher among infected than among healthy cows. Error and additive variance components obtained under the mixture model were closer to simulated values than restricted maximum likelihood estimates obtained assuming a homogeneous SCS distribution, especially when subpopulations were completely separated and when mixing proportion was highest. Convergence was linear and rapid when priors were chosen with caution. The advantages of the methodology are demonstrated, and its feasibility for large data sets is discussed. [less ▲]

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See detailComparative Evaluation of Four Detectors in the High-Performance Liquid Chromatographic Analysis of Chiral Nonaromatic Alcohols
Toussaint, B.; Duchateau, A. L.; van der Wal, S. et al

in Journal of Chromatographic Science (2000), 38(10), 450-7

A comparative evaluation of ultraviolet, polarimetric, refractive index, and evaporative light-scattering detection coupled with high-performance liquid chromatography has been developed for the ... [more ▼]

A comparative evaluation of ultraviolet, polarimetric, refractive index, and evaporative light-scattering detection coupled with high-performance liquid chromatography has been developed for the separation and quantitation of the enantiomers of chiral nonaromatic alcohols, some of which are intermediates in the synthesis of chiral drugs. (R,S)-3-tert-butylamino-1,2-propanediol; (R,S)-glycidol; and (R,S)-1-(4-morpholino)-2-octanol are selected as model compounds in order to compare the detection sensitivity and the linearity of the response with the four detectors. Separation of the enantiomers is performed using chiral stationary phases in normal-phase liquid chromatography. A one-day validation is achieved for (S)-3-tert-butylamino-1,2-propanediol with each detector, and limits of quantitation are determined for the three compounds. Advantages and limitations of the four detectors are discussed. [less ▲]

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See detailLe cas clinique du mois. A propos d'une presentation inhabituelle de syndrome cave superieur
Monami, Catherine; Martinez, Christophe ULg; Ghuysen, Alexandre ULg et al

in Revue Médicale de Liège (2000), 55(10), 905-9

We report the case of a 48-year-old man who was admitted to our emergency department because of a superior vena caval syndrome from which the symptoms occurred only during exercise. His past history ... [more ▼]

We report the case of a 48-year-old man who was admitted to our emergency department because of a superior vena caval syndrome from which the symptoms occurred only during exercise. His past history included an episode of lower limb deep venous thrombosis. Because an atrio-ventricular partial block was fortuitously evidenced, the patient was submitted to a pacemaker insertion. A few years later, the patient suffered from rapid dyspnea on exercise, associated with facial cyanosis and systemic hypotension. The exploration by phlebography evidenced that the inferior vena cava was completely obstructed. Therefore the venous return from the lower part of the body to right heart was obtained through hypertrophy of the vena azygos. In addition, the presence of cardiac pacing electrodes induced a stenosis at the level of the superior vena cava, just before its entrance into the right atrium. Such a venous network accounted for the occurrence of a chronic superior vena caval syndrome associated with peripheral arterial hypotension during exercise. Treatment consisted of a superior vena caval percutaneous transluminal balloon angioplasty followed by a Wallstent insertion. This procedure led to a correction of all hemodynamic abnormalities responsible for reported pathophysiological limitations to stress. [less ▲]

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See detailLa chirurgie du thymus, normal, involue ou tumoral
Limet, Raymond ULg; Rogister, Bernard ULg

in Revue Médicale de Liège (2000), 55(10), 940-4

Thymoma is the most frequently resected mediastinal tumor. Its malignancy is related more to macroscopical findings than to microscopical analysis. All thymomas should be resected, in order to prevent ... [more ▼]

Thymoma is the most frequently resected mediastinal tumor. Its malignancy is related more to macroscopical findings than to microscopical analysis. All thymomas should be resected, in order to prevent malignant degeneration. Furthermore, for the treatment of myasthenia, several centers recommend resection of the thymus, either tumoral (thymoma) or atrophied. Although the role of surgery in this regard is controversial, all authors unanimously stress that complete resection of all thymic remnants is essential to achieve adequate results. [less ▲]

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See detailSurface structure of thin film blends of polystyrene and poly(n-butyl methacrylate)
Affrossman, S.; Jérôme, Robert ULg; O'Neill, S. A. et al

in Colloid and Polymer Science (2000), 278(10), 993-999

Thin films of blends of polystyrene (PS) and poly(n-butyl methacrylate) (PBMA) were prepared by spin-casting onto silicon wafers in order to map the lateral distribution of the two polymers. The surfaces ... [more ▼]

Thin films of blends of polystyrene (PS) and poly(n-butyl methacrylate) (PBMA) were prepared by spin-casting onto silicon wafers in order to map the lateral distribution of the two polymers. The surfaces were examined by atomic force microscopy (AFM) secondary ion mass spectroscopy X-ray photoelectron spectroscopy (XPS) and photoemission electron microscopy (PEEM). Films with PBMA contents of 50% w/w or less were relatively smooth, but further increase in the PBMA content produced, initially, protruding PS ribbons and then, for PBMA ≥80% w/w, isolated PS islands. At all concentrations the topmost surface (0.5-1.0 nm) was covered by PBMA, whilst the PBMA concentration in the near-surface region, measured by XPS, increased with bulk content to eventual saturation. PEEM measurements of a PS-PBMA film at the composition at which ribbon features were observed by AFM also showed a PS-rich ribbon structure surrounded by a sea of mainly PBMA. [less ▲]

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See detailCephalees explosives, "en coup de tonnerre": faut-il s'inquieter?
DELVAUX, Valérie ULg; vandenheede, michel; Schoenen, Jean ULg

in Revue Médicale de Liège (2000), 55(10), 910914

"Thunderclap" headaches are explosive, extremely intense and sometimes associated with neurological signs or symptoms. As illustrated by the 3 case histories presented here, they are a heterogenous group ... [more ▼]

"Thunderclap" headaches are explosive, extremely intense and sometimes associated with neurological signs or symptoms. As illustrated by the 3 case histories presented here, they are a heterogenous group as far as etiology and prognosis are concerned. They may be symptomatic of an intracranial disorder (subarachnoid hemorrhage, cerebral venous thrombosis, pituitary apoplexia) or idiopathic without any known cause and with a benign, though occasionally recurring, course. They can be spontaneous or triggered by Valsalva maneuvers (cough, exertion, coitus, ...). In certain cases of so-called "idiopathic" thunderclap headache, diffuse, multifocal segmental and reversible vasospasm of cerebral arteries has been found on neuroimaging. As headache characteristics are similar in symptomatic and benign cases, angio-MRI is recommended when CT-scan and CSF examination are normal. [less ▲]

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See detail2-(2-Oxoimidazolidinyl)Ethyl 2-Methylprop-2-Enoate
Spirlet, Marie-Rose ULg; Desreux, Jean-François ULg; Riondel, A. et al

in Acta Crystallographica Section C-Crystal Structure Communications (2000), 56((Pt 10)), 1258-9

In the crystal structure of the title compound, C(9)H(14)N(2)O(3), the molecules are linked by N-H.O=C bonds into chains parallel to [001]. Large crystals are readily obtained, presumably because of the ... [more ▼]

In the crystal structure of the title compound, C(9)H(14)N(2)O(3), the molecules are linked by N-H.O=C bonds into chains parallel to [001]. Large crystals are readily obtained, presumably because of the hydrogen bonds and an energetically stable conformation of the molecule. [less ▲]

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See detailNew Functional Aliphatic Polyesters by Chemical Modification of Copolymers of ε-Caprolactone with γ-(2-Bromo-2-methylpropionate)- ε-caprolactone, γ-Bromo- ε-caprolactone, and a Mixture of β-and γ-Ene- ε-caprolactone
Detrembleur, Christophe ULg; Mazza, Michaël; Lou, Xudong et al

in Macromolecules (2000), 33(17), 7751-7760

New functional aliphatic polyesters were prepared by chemical modification of brominated copolyesters. Poly(epsilon-caprolactone)-co-poly(gamma-(2-bromo-2-methylpropionate)-epsilon-caprolactone) copolymer ... [more ▼]

New functional aliphatic polyesters were prepared by chemical modification of brominated copolyesters. Poly(epsilon-caprolactone)-co-poly(gamma-(2-bromo-2-methylpropionate)-epsilon-caprolactone) copolymer was prepared and successfully converted into copolyester bearing methacrylate double bonds by dehydrohalogenation of the pendant tertiary alkyl bromides, thus leading to cross-linkable polyester. The tertiary alkyl bromide groups of the original copolyester were also quaternized by reaction with pyridine, although some side reactions occurred which Limited the reaction yield. Nevertheless, quaternization of the bromide groups of the poly(epsilon-caprolactone)-co-poly(gamma-bromo-epsilon-caprolactone) copolymer proved to be quantitative and to occur without degradation of the polyester chains. This general strategy paves the way to either amphiphilic copolyesters or water-soluble polyesters. The poly(epsilon -caprolactone)-co-poly(gamma -bromo-epsilon-caprolactone) lactone) copolymer was also quantitatively converted into unsaturated copolyester by dehydrohalogenation with formation of double bonds including acrylic-type double bonds. As an alternative, gamma-bromo-epsilon-caprolactone was first dehydrohalogenated, and the unsaturated cyclic monomer was copolymerized with epsilon-caprolactone. Finally, the nonconjugated double bonds of the copolyesters were oxidized into epoxides, except for the acrylic-type unsaturations which remained unchanged. [less ▲]

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See detailAdditive Effect between Nf-Kappab Subunits and P53 Protein for Transcriptional Activation of Human P53 Promoter
Benoit, V.; Hellin, A. C.; Huygen, S. et al

in Oncogene (2000), 19(41), 4787-94

The tumor suppressor p53 plays a pivotal role in the cellular response to DNA damage as it controls DNA repair, cell cycle arrest and apoptosis. We studied the autoregulation of human p53 gene ... [more ▼]

The tumor suppressor p53 plays a pivotal role in the cellular response to DNA damage as it controls DNA repair, cell cycle arrest and apoptosis. We studied the autoregulation of human p53 gene transcription in colon cancer cell lines. Wild-type p53 has been shown to autoregulate its own transcription either positively or negatively and probably in a cell-type-specific manner. Indeed, a p53 binding site has been described in the human and murine p53 promoters, but a direct binding of wild-type p53 protein to this site has never been reported. In this study, we demonstrated a transactivation of human p53 promoter by wild-type p53 in human colon cancer cells. We identified in the human p53 promoter a novel potential p53-responsive element that binds wild-type p53. Moreover, wild-type p53 protein transactivated a reporter plasmid containing a luciferase gene driven by a minimal promoter harboring this p53 binding site. Finally, as the p53 promoter contains an NF-kappaB binding site, we demonstrated an additive effect when NF-kappaB subunits and p53 protein combined to transactivate the human p53 promoter. [less ▲]

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See detailL'actualité du (futur) permis d'environnement en Région wallonne
Delnoy, Michel ULg

in Immobilier (2000), 16

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See detailCIKS, a connection to Ikappa B kinase and stress-activated protein kinase.
Leonardi, Antonio; Chariot, Alain ULg; Claudio, Estefania et al

in Proceedings of the National Academy of Sciences of the United States of America (2000), 97(19), 10494-10499

Pathogens, inflammatory signals, and stress cause acute transcriptional responses in cells. The induced expression of genes in response to these signals invariably involves transcription factors of the NF ... [more ▼]

Pathogens, inflammatory signals, and stress cause acute transcriptional responses in cells. The induced expression of genes in response to these signals invariably involves transcription factors of the NF-kappaB and AP-1/ATF families. Activation of NF-kappaB factors is thought to be mediated primarily via IkappaB kinases (IKK), whereas that of AP-1/ATF can be mediated by stress-activated protein kinases (SAPKs; also named Jun kinases or JNKs). IKKalpha and IKKbeta are two catalytic subunits of a core IKK complex that also contains the regulatory subunit NEMO (NF-kappaB essential modulator)/IKKgamma. The latter protein is essential for activation of the IKKs, but its mechanism of action is not known. Here we describe the molecular cloning of CIKS (connection to IKK and SAPK/JNK), a previously unknown protein that directly interacts with NEMO/IKKgamma in cells. When ectopically expressed, CIKS stimulates IKK and SAPK/JNK kinases and it transactivates an NF-kappaB-dependent reporter. Activation of NF-kappaB is prevented in the presence of kinase-deficient, interfering mutants of the IKKs. CIKS may help to connect upstream signaling events to IKK and SAPK/JNK modules. CIKS could coordinate the activation of two stress-induced signaling pathways, functions reminiscent of those noted for tumor necrosis factor receptor-associated factor adaptor proteins. [less ▲]

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See detailGrowth Regulation of Astrocytes and C6 Cells by Tgfbeta1: Correlation with Gap Junctions
Robe, Pierre ULg; Rogister, Bernard ULg; Merville, Marie-Paule ULg et al

in Neuroreport (2000), 11(13), 2837-41

Transforming growth factor (TGF) beta1 enhanced in vitro [3H]thymidine incorporation into C6 cells and reduced that of astrocytes in the presence of a high serum concentration. It concomitantly raised the ... [more ▼]

Transforming growth factor (TGF) beta1 enhanced in vitro [3H]thymidine incorporation into C6 cells and reduced that of astrocytes in the presence of a high serum concentration. It concomitantly raised the gap junction intercellular communication (GJIC) in normal astrocytes but reduced the coupling of C6 cells, and respectively increased or decreased the proportion of P2-phosphorylated connexin (Cx) 43 isoform in these cells. Finally, octanol, which inhibited GJIC in both cell types, increased the thymidine incorporation in C6 cells, but neither altered the proliferation of astrocytes nor their response to TGFbeta1. These data indicate that an inhibition of gap junction intercellular communication, due to an altered phosphorylation of connexin 43, may contribute to the proliferative response of C6 glioblastoma cells to TGFbeta1. [less ▲]

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See detailTaxation des plus-values immobilières résultant des plans d'aménagement
Delnoy, Michel ULg

in Immobilier (2000), 15

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See detailElectrochemical synthesis of conjugated polymer wires and nanotubules
Jérôme, Christine ULg; Demoustier-Champagne, Sophie; Legras, Roger et al

in Chemistry : A European Journal (2000), 6(17), 3089-3093

Two electrochemical methods designed for the synthesis of polypyrrole (PPy) wires and nanotubules are the topic of this paper. The concept that allows the morphology of PPy to be controlled is discussed ... [more ▼]

Two electrochemical methods designed for the synthesis of polypyrrole (PPy) wires and nanotubules are the topic of this paper. The concept that allows the morphology of PPy to be controlled is discussed for each method, and the performances of the two complementary techniques are compared in terms of dimension, shape and conductivity of PPy. [less ▲]

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See detailLensed quasars: a matter of resolution
Courbin, F.; Lidman, C.; Burud, I. et al

in The Messenger (2000), 101

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See detailCoordinated monitoring of the eccentric O-star binary Iota Orionis: optical spectroscopy and photometry
Marchenko, Sergey V; Rauw, Grégor ULg; Antokhina, Eleonora A et al

in Monthly Notices of the Royal Astronomical Society (2000), 317

With the objective of investigating the wind-wind collision phenomenon and supporting contemporaneous X-ray observations, we have organized a large-scale, coordinated optical monitoring campaign of the ... [more ▼]

With the objective of investigating the wind-wind collision phenomenon and supporting contemporaneous X-ray observations, we have organized a large-scale, coordinated optical monitoring campaign of the massive, highly eccentric O9III+B1III binary Iota Orionis. Successfully separating the spectra of the components, we refine the orbital elements and confirm the rapid apsidal motion in the system. We also see strong interaction between the components during periastron passage and detect phase-locked variability in the spectrum of the secondary star. However, we find no unambiguous signs of the bow shock crashing on the surface of the secondary, despite the predictions of hydrodynamic simulations. Combining all available photometric data, we find rapid, phase-locked variations and model them numerically, thus restricting the orbital inclination to 50°<~i<~70°. [less ▲]

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See detailCompact star clusters of the LMC H ii region N11 C
Heydari-Malayeri, Mohammad; Royer, Pierre; Rauw, Grégor ULg et al

in Astronomy and Astrophysics (2000), 361

Based on imaging and spectroscopy obtained at the ESO NTT telescope and using an efficient image analysis algorithm, we study the core of the LMC OB association LH 13, particularly the two compact stellar ... [more ▼]

Based on imaging and spectroscopy obtained at the ESO NTT telescope and using an efficient image analysis algorithm, we study the core of the LMC OB association LH 13, particularly the two compact stellar clusters Sk-66[SUP]deg[/SUP]41, and HNT in the H ii, region N 11C. We resolve Sk-66[SUP]deg[/SUP]41, into 15 components and for the first time the HNT cluster into 70 stars, and derive photometry for the members. Moreover, from medium resolution spectroscopy we determine the spectral types for sixteen stars in N 11C. We compare the color-magnitude diagrams of the clusters with that of the field stars and discuss the cluster ages. With an age of ~ ,100 Myr, the HNT cluster appears significantly older than the very young (<= 5 Myr) Sk-66[SUP]deg[/SUP]41, starburst. We suggest that most of the `field' O-stars in the core of N 11C have actually been ejected from Sk-66[SUP]deg[/SUP]41, through dynamical interactions in the compact cluster. The properties of the Sk-66[SUP]deg[/SUP]41, and HNT clusters suggest that we are viewing different star formation regions lying at different distances along the same line of sight. Based on observations obtained at the European Southern Observatory, La Silla, Chile [less ▲]

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See detailOptimal extraction of multiple overlapping spectra: a new algorithm based on the maximum entropy method
Khmil, S. V.; Surdej, Jean ULg

in Kinematika i Fizika Nebesnykh Tel Supplement (2000), 3

A general algorithm of slit spectra extraction for a system of point-like sources (e.g. multiple lensed images of the same quasar) has been developed, assuming that the point-spread function (PSF) of the ... [more ▼]

A general algorithm of slit spectra extraction for a system of point-like sources (e.g. multiple lensed images of the same quasar) has been developed, assuming that the point-spread function (PSF) of the measuring instrument and the positions of the spectra relative to the CCD frame are unknown. The main idea of the algorithm is to successively apply the maximum entropy method to each set of parameters, such as the spectra, the PSF, and the spectra positions, in order to iteratively improve their values. The algorithm uses all the a priori knowledge about the spectra (e.g. flux positivity, relative magnitudes between the components, astrometry, etc.) to compute the initial parameter sets. After careful testing, the algorithm was applied to extract the spectra of the gravitationally lensed system Q1009-0252 A & B (I[SUB]B[/SUB]/I[SUB]A[/SUB]=0.1, θ[SUB]AB[/SUB]=1.''55, 1{pxl}=0.''44, typical seeing FWHM=0.''8). [less ▲]

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See detailProgesterone Receptor Activation. An Alternative to SERMs in Breast Cancer
Desreux, Joëlle ULg; Kebers, F.; Noël, Agnès ULg et al

in European Journal of Cancer (2000), 36(Suppl 4), 90-1

Data regarding the effects of progesterone and a progestagen on human normal breast epithelial cell proliferation and apoptosis are presented here. In postmenopausal women, adding progesterone to ... [more ▼]

Data regarding the effects of progesterone and a progestagen on human normal breast epithelial cell proliferation and apoptosis are presented here. In postmenopausal women, adding progesterone to percutaneously administrated oestradiol significantly reduces the proliferation induced by oestradiol. In vitro and in premenopausal women, stopping the administration of nomegestrol acetate triggers a peak of apoptosis. Fibro-adenoma and cancerous cells do not show this regulation of apoptosis. Progesterone seems to be important in normal breast homeostasis. [less ▲]

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See detailL'union libre et la réparation des accidents mortels de travail
Michiels, Olivier ULg

in Divorce : Actualité Juridique, Sociale et Fiscale (2000), 9

L'article s'attache à la question de l'indemnisation du compagnon ou de la campagne d'un travailleur qui décède au cours d'un accident du travail.

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See detailPathologie hypophysaire et NEM 1
Betea, Daniela ULg; Valdes Socin, Hernan Gonzalo ULg; Beckers, Albert ULg

in Annales d'Endocrinologie (2000), 61(3), 214-223

Multiple Endocrine Neoplasia type 1 (MEN 1) is an autosomal dominant syndrome characterized by neoplasia of the parathyroid glands, the endocrine pancreas and the anterior pituitary gland. Recently the ... [more ▼]

Multiple Endocrine Neoplasia type 1 (MEN 1) is an autosomal dominant syndrome characterized by neoplasia of the parathyroid glands, the endocrine pancreas and the anterior pituitary gland. Recently the identification on chromosome 11 (locus q13) of the gene responsible for MEN 1 has allowed direct genetic diagnosis of MEN 1-affected family members. To date almost 300 families have been described and genetically characterized. The genetic etiology of most pituitary tumours remains unknown. Pituitary adenomas can develop sporadically or as a part of multiple endocrine neoplasia type 1. In this review, the recently published data on the pathology of the MEN 1 syndrome will be summarized. The clinical, morphological and genetic aspects of sporadic and MEN 1-associated pituitary adenomas will be outlined. [less ▲]

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See detailTernary polymer blend with core-shell dispersed phases: effect of the core-forming polymer on phase morphology and mechanical properties
Luzinov, Igor; Pagnoulle, Christophe; Jérôme, Robert ULg

in Polymer (2000), 41(19), 7099-7109

Phase morphology and mechanical properties of ternary blends consisting of PS (polystyrene), SBR (styrene butadiene rubber) and different polyolefins (POs) have been studied. PS, systematically forms the ... [more ▼]

Phase morphology and mechanical properties of ternary blends consisting of PS (polystyrene), SBR (styrene butadiene rubber) and different polyolefins (POs) have been studied. PS, systematically forms the matrix, SBR and PO being combined in the dispersed phase. Although POs of various melt viscosity and stiffness are used, the binary (SBR/PO) dispersed phase is of a core-shell structure, in which PO forms the core. Upon increasing the viscosity of PO, the average size of the cores and the SBR domains including them increases. Comparison of the experimental shear storage modulus of the blends with theoretical predictions indicates that the stress transfer from the PS matrix to the PO core through the SBR shell depends on the modulus of the SBR envelope. The ultimate mechanical properties of the ternary blends are sensitive to the stiffness of the PO core. [less ▲]

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See detailTatouages. Du rituel a la parure avec leurs complications
Paquet, Philippe ULg; Pierard, Gérald ULg; Nikkels, Arjen ULg et al

in Revue Médicale de Liège (2000), 55(9), 847-849

Tattoos are performed for distinct purposes which range from social rituals to aesthetic aims. They are permanent or transient according to the site of the pigments being located either in the dermis or ... [more ▼]

Tattoos are performed for distinct purposes which range from social rituals to aesthetic aims. They are permanent or transient according to the site of the pigments being located either in the dermis or in the stratum corneum, respectively. Tattoos may be responsible for allergic reactions, infections or psychological distress of the subject who requests to be relieved of it. [less ▲]

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See detailOntogeny of Aromatase and Tyrosine Hydroxylase Activity and of Aromatase-Immunoreactive Cells in the Preoptic Area of Male and Female Japanese Quail
Balthazart, Jacques ULg; Tlemcani, O.; Harada, N. et al

in Journal of Neuroendocrinology (2000), 12(9), 853-66

The aromatization of testosterone into oestrogens plays a key role in the control of many behavioural and physiological aspects of reproduction. In the quail preoptic area (POA), aromatase activity and ... [more ▼]

The aromatization of testosterone into oestrogens plays a key role in the control of many behavioural and physiological aspects of reproduction. In the quail preoptic area (POA), aromatase activity and the number of aromatase-immunoreactive (ARO-ir) cells are sexually differentiated (males > females). This sex difference is implicated in the control of the sexually dimorphic behavioural response of quail to testosterone. We analysed the ontogenetic development of this sex difference by measuring aromatase activity and counting ARO-ir cells in the POA of males and females from day 1 post hatch to sexual maturity. We investigated in parallel another enzyme: tyrosine hydroxylase, the rate limiting step in catecholamine synthesis. Between hatching and 4 weeks of age, aromatase activity levels were low and equal in males and females. Aromatase activity then markedly increased in both sexes when subjects initiated their sexual maturation but this increase was more pronounced in males so that a marked difference in aromatase activity was present in 6 and 8 week-old subjects. Tyrosine hydroxylase activity progressively increased with age starting immediately after hatching and there was no abrupt modification in the slope of this increase when birds became sexually mature. No sex difference was detected in the activity of this enzyme. The number of ARO-ir cells in the POA progressively increased with age starting at hatching. No sex difference in ARO-ir cell numbers could be detected before subjects reached full sexual maturity. The analysis of the three-dimensional organization of ARO-ir cells in the POA revealed that, with increasing ages, ARO-ir cells acquire a progressively more lateral position: they are largely periventricular in young birds but they are found at higher density in the lateral part of the medial preoptic nucleus in adults. These data indicate that aromatase activity differentiates sexually when birds reach sexual maturity presumably under the activating effects of the increased testosterone levels in males. The number of ARO-ir cells, however, begins to increase in a non sexually differentiated manner before the rise in plasma testosterone in parallel with the increased tyrosine hydroxylase activity. Whether this temporal coincidence results from a general ontogenetic pattern or from more direct causal links remains to be established. [less ▲]

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See detailFracture and Bone Mineral Density in Hemodialysis Patients
Fontaine, M. A.; Albert, Adelin ULg; Dubois, Bernard ULg et al

in Clinical Nephrology (2000), 54(3), 218-26

AIM: The aim of this cross-sectional study was to determine in hemodialysis patients the pattern of low trauma fracture, the ability of dual X-ray absorptiometry (DXA) to discriminate between patients ... [more ▼]

AIM: The aim of this cross-sectional study was to determine in hemodialysis patients the pattern of low trauma fracture, the ability of dual X-ray absorptiometry (DXA) to discriminate between patients with and without fracture, and the magnitude, distribution and mechanism of bone loss. PATIENTS AND METHODS: Eighty-eight patients were studied. Bone mineral density (BMD) was measured by DXA at lumbar spine (LS), femoral neck (FN) and 3 radius sites (UD, MID and 1/3R). In 11 patients (12.5%), 16 fractures occurred and were predominant at the distal forearm and ribs. RESULTS: Patients with fracture had a significatively lower BMD Z-score at LS (-1.34 +/- 1.66 vs -0.42 +/- 1.23), at FN (-1.58 +/- 1.25 vs -0.60 +/- 1.01), at MID radius (-2.59 +/- 1.34 vs -0.93 +/- 1.76) and 1/3 radius (-1.62 +/- 1.60 vs -0.39 +/- 1.32). They also had a longer history of dialysis (113 +/- 64 vs 53 +/- 65 months). Prevalence of osteoporosis varied from 23% at LS to 50% at MID radius. CONCLUSION: Multiple regression analysis showed that there was no influence of gender, age, parathormone status and primary renal disease on BMD. However, at FN, UD, MID and 1/3 radius, a significantly negative correlation was found between length of dialysis and BMD Z-score. By contrast at LS, there was a positive correlation between age at onset of dialysis and BMD Z-score. Despite occurrence of fracture at the fistula forearm, BMD levels were similar in both arms. [less ▲]

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See detailVoxel-based distribution of metabolic impairment in corticobasal degeneration
Garraux, Gaëtan ULg; Salmon, Eric ULg; Peigneux, Philippe ULg et al

in Movement Disorders (2000), 15(5), 894-904

This report emphasizes the precise topographic distribution of cerebral metabolic impairment in corticobasal degeneration (CBD) and the pathophysiological differences between CBD and progressive ... [more ▼]

This report emphasizes the precise topographic distribution of cerebral metabolic impairment in corticobasal degeneration (CBD) and the pathophysiological differences between CBD and progressive supranuclear palsy (PSP). Statistical parametric mapping (SPM96) analysis of 18FDG positron emission tomography (PET) data was performed in 22 patients with CBD compared with 46 healthy subjects (HS) and 21 patients with PSP who were studied at rest. A statistical threshold of p <0.001 was fixed, further corrected for multiple or independent comparisons (p <0.05). In comparison with HS, the metabolic impairment in CBD was asymmetrically distributed in the putamen, thalamus, precentral (Brodmann's area, BA 4), lateral premotor (BA 6/44) and supplementary motor areas (SMA, BA 6), dorsolateral prefrontal (8/9/46) cortex, and the anterior part of the inferior parietal lobe (BA 40) including the intraparietal sulcus (BA 7/40). A similar hypometabolic pattern was observed for most individual analyses. When PSP was compared with CBD, metabolic impairment predominated in the midbrain, anterior cingulate (BA 24/32), and orbitofrontal regions (BA 10). The reverse contrast showed more posterior involvement in CBD (BA 6 and 5/7/40) including SMA. Our data suggest that multiple components of neural networks related to both movement execution and production of skilled movements are functionally disturbed in CBD compared with both HS and PSP. [less ▲]

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See detailH NMR investigations on water dynamics during starch gels retrogradation.
Burtea, C.; Roch, A.; Pierart, Céline ULg et al

in Magnetic Resonance Materials in Biology, Physics and Medicine (2000), 11(Suppl. 1),

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See detailTraitement de la maladie de Crohn de l'adulte par anticorps anti-tumor necrosis factor-alpha (TNF alpha)
Belaiche, Jacques ULg; Louis, Edouard ULg

in Revue Médicale de Liège (2000), 55(9), 827-32

Crohn's disease (CD) is a chronic inflammatory disease of the bowel characterized by segmental transmural inflammation and granulomatous changes. TNF alpha is a member of a large family of proteins and ... [more ▼]

Crohn's disease (CD) is a chronic inflammatory disease of the bowel characterized by segmental transmural inflammation and granulomatous changes. TNF alpha is a member of a large family of proteins and receptors that are involved in immune regulation. It is a proinflammatory and immunoregulatory cytokine synthesized by monocytes, macrophages, and T cells. TNF alpha plays an early central role in the cytokine cascade of the inflammatory process. Recently, chimeric monoclonal antibodies that inhibits TNF alpha have been used in the treatment of Crohn's disease. Infliximab has been the most largely used antibody. It is commercialized in the USA and has recently obtained an European marketing approvement. Infliximab is indicated for the treatment of moderately to severely active CD in patients having an inadequate response to conventional therapy. Clinical trials have demonstrated efficacy when the agent is initiated as a 5 mg/kg single intravenous infusion. In patients with fistulizing CD, administration of 2 subsequent 5 mg/kg doses 2 and 6 weeks after the initial dose appears to be efficacious. Limited clinical data also suggest that infliximab retreatment regimen restores response and maintains remission rates. Infliximab appears to be well tolerated. To date, very little is known about the potential for long-term toxicity with infliximab therapy. [less ▲]

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See detailHereditary motor and sensory neuropathy with absence of large myelinated fibers due to absence of large neurons in dorsal root ganglia and anterior horns, clinically associated with deafness, mental retardation, and epilepsy (HMSN-ADM).
Muller, H. D.; Mugler, M.; RAMAEKERS, Vincent ULg et al

in Journal of the peripheral nervous system : JPNS (2000), 5(3), 147-57

Hereditary motor and sensory neuropathy (HMSN) with autosomal recessive inheritance represents a genetically heterogeneous group of disorders with variable clinical, pathologic and electrophysiologic ... [more ▼]

Hereditary motor and sensory neuropathy (HMSN) with autosomal recessive inheritance represents a genetically heterogeneous group of disorders with variable clinical, pathologic and electrophysiologic manifestations. A new variant of autosomal recessive HMSN, clinically defined by sensorimotor polyneuropathy associated with deafness and mental retardation, has recently been described. We report on the first autopsy case with this type of HMSN: a girl of non-consanguineous parents with a presumably autosomal recessive type of motor and sensory neuropathy clinically associated with deafness, mental retardation, and epilepsy. The autopsy showed complete absence of large myelinated fibers in peripheral motor and sensory nerves corresponding to a lack of large neurons in dorsal root ganglia and anterior horns of the spinal cord, moderate neurogenic muscle atrophy, and nearly complete absence of neurons in the dentate nucleus of the cerebellum. Molecular genetic analyses in our case revealed neither genetic alterations in the survival motor neuron gene nor in the PMP-22 gene. [less ▲]

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See detailEarly Stage Results after Oesophageal Resection for Malignancy - Colon Interposition Vs. Gastric Pull-Up
Kolh, Philippe ULg; Honore, Pierre ULg; Degauque, C. et al

in European Journal of Cardio - Thoracic Surgery (2000), 18(3), 293-300

OBJECTIVE: The aims of our study were to determine if using the colon as a digestive transplant after oesophagectomy for cancer was associated with increased postoperative complications, and to assess the ... [more ▼]

OBJECTIVE: The aims of our study were to determine if using the colon as a digestive transplant after oesophagectomy for cancer was associated with increased postoperative complications, and to assess the impact of preoperative radiochemotherapy on postoperative hospital outcome. METHODS: From January 1990 to December 1998, 130 patients underwent oesophageal resection for malignancy. There were 103 males and 27 females (age: 61.3+/-11.5 years). Indications were squamous cell carcinoma in 69 patients and adenocarcinoma in 61. Preoperatively 30 patients (eight in stage IIB, 18 in stage III, and four in stage IV) received radiochemotherapy. There were 84 subtotal oesophagectomies, with anastomosis in the neck in 44 patients and at the thoracic inlet in 40, and 46 distal oesophageal resections. Digestive continuity was restored with the stomach in 92 patients (age: 63.4+/-10.2 years) and the colon in 38 (age: 52.3+/-12.8 years). With the exception of age (P<0.0001), there was no significant preoperative difference between gastric and colonic groups. RESULTS: Hospital mortality was 8.5% (11 patients), decreasing from 18.5% (before 1993) to 3.8% (since 1993). One patient (2.5%) died in the colonic graft group and ten (11%) in the gastric pull-up group (P=0.17). Postoperative complications occurred in 40 patients (31%), respectively, in ten (26%) and 30 (33%) patients after colonic and gastric transplants (P=0.48), and were pulmonary insufficiency or infection in 29 patients, anastomotic fistula in six, myocardial infarction in five, recurrent nerve palsy in four, renal insufficiency in three, and cerebrovascular accident in one. All fistulas occurred in the gastric pull-up group. The incidence of postoperative pulmonary complications was 70% (21/30 patients) in the subgroup who received preoperative radiochemotherapy, as compared to 11% (5/44 patients) in the subgroup of comparable staging, but without preoperative treatment (P<0.001). CONCLUSIONS: Colonic grafts are not associated with increased postoperative mortality or complications. Our results suggest that preoperative neoadjuvant treatment significantly increases postoperative pulmonary complications. [less ▲]

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See detailMelatonine. II. Actions physiologiques et therapeutiques
Bruls, E.; Crasson, Marion ULg; Van Reeth, O. et al

in Revue Médicale de Liège (2000), 55(9), 862-70

Melatonin is a hormone mainly secreted by the pineal gland during the dark phase of the light-dark cycle. The most known function of melatonin in mammals is to transmit information concerning light-dark ... [more ▼]

Melatonin is a hormone mainly secreted by the pineal gland during the dark phase of the light-dark cycle. The most known function of melatonin in mammals is to transmit information concerning light-dark cycles playing the role of an active neuroendocrine transducer of environmental information. Given this chronobiologic role of pineal melatonin, it seems to be useful in the management of shift work, jet lag and some sleep disorders. In vitro like in vivo melatonin seems to be effective as an antioxidant and oncostatic agent. Melatonin may provide protection against aging process, degenerative diseases, cancer and play a role also in sexual maturation, reproduction, immune function and psychiatric illness. The administration of melatonin in the jet-lag syndrome is well codified. Further clinical research is needed for a better understanding and definition of other indications, treatment regimens and safety of the hormone. The aim of this paper is to review the current knowledge on its clinical implications. [less ▲]

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See detailRegrets apres sterilisation tubaire
Nervo, Patricia ULg; Bawin, L.; Foidart, Jean-Michel ULg et al

in Journal de Gynécologie, Obstétrique et Biologie de la Reproduction (2000), 29(5), 485-91

OBJECTIVE: To examine thoroughly the profile and motivations of a group of women who regretted sterilization so much that they were prepared to undergo reversal microsurgery or in vitro fertilization ... [more ▼]

OBJECTIVE: To examine thoroughly the profile and motivations of a group of women who regretted sterilization so much that they were prepared to undergo reversal microsurgery or in vitro fertilization treatment. MATERIAL: and methods. The study followed one hundred women from their first consultation for a period of 3 years in order to analyze the outcome of their initial decision. RESULTS: Analysis of the circumstances at the time of the sterilization indicate 3 main factors which later caused the women to regret the decision Three years after the initial consultation, 69% of the patients have withdrawn from further investigation and /or treatment for different reasons analyzed in this study. 17 of the patients have undergone reversal microsurgery and 14 have attempted one or more in vitro fertilization treatments. Of these 31 patients, 12 (38.7%) have given birth to at least one child. CONCLUSION: These results sufficiently prove that tubal sterilization is worthy of consideration as much by the patient as by the physician as a method of irreversible contraception despite the developments in tubal microsurgery or in medically assisted procreation. [less ▲]

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See detailInv(12)(Q15q24): A Nonrandom Change Associated with Myelodysplasia?
Scantamburlo, Gabrielle ULg; Lampertz, serge; Jamar, Michelle ULg et al

in Cancer Genetics & Cytogenetics (2000), 121(2), 206-7

A patient with refractory anemia and a paracentric inversion of chromosome 12, inv(12)(q15q24), is described. This is the second reported case with this chromosome anomaly, suggesting that this ... [more ▼]

A patient with refractory anemia and a paracentric inversion of chromosome 12, inv(12)(q15q24), is described. This is the second reported case with this chromosome anomaly, suggesting that this rearrangement is a rare but nonrandom change associated with myelodysplastic syndromes. [less ▲]

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See detailCombined Suicide and Cytokine Gene Therapy for Peritoneal Carcinomatosis
Lechanteur, Chantal ULg; Delvenne, Philippe ULg; Princen, Frédéric et al

in Gut (2000), 47(3), 343-8

BACKGROUND: Gene therapy is a novel approach for the treatment of cancers, and tumours disseminated in the peritoneal cavity are suitable for in situ delivery of a therapeutic gene. AIMS: The efficacy of ... [more ▼]

BACKGROUND: Gene therapy is a novel approach for the treatment of cancers, and tumours disseminated in the peritoneal cavity are suitable for in situ delivery of a therapeutic gene. AIMS: The efficacy of a therapy combining a suicide gene (herpes simplex virus type I thymidine kinase (HSV-TK)) and cytokine genes was investigated in a model of peritoneal carcinomatosis induced by colon carcinoma cells in syngeneic rats. MATERIAL AND METHODS: Pre-established macroscopic tumours in BDIX rats were treated by intraperitoneal injections of retrovirus producing cells (FLYA13 TK, FLYA13 granulocyte macrophage-colony stimulating factor (GM-CSF), FLYA13 interleukin 12 (IL-12)) and ganciclovir (GCV). RESULTS: TK/GCV treated animals showed a slight increase in survival time (72 days) compared with the control group (63 days) while the association of cytokine and TK/GCV gene therapy resulted in significantly improved survival, with a large proportion of animals remaining tumour free on day 480 (60% and 40% for TK/GCV/GM-CSF and TK/GCV/IL-12 treated animals, respectively). Histological analysis of treated animals showed that the remaining tumour nodes were infiltrated by mononuclear cells but no major differences were observed between the various treatments. Immunohistochemical analysis revealed that lymphoid CD4(+) and CD8(+) T cells as well as macrophages accumulated outside untreated tumour nodes while CD8(+) and CD25(+) activated T cells and macrophages heavily infiltrated the tumours after the different treatments. CONCLUSIONS: Our data indicate that combined suicide and cytokine gene therapy is a powerful approach for the treatment of macroscopic peritoneal carcinomatosis. [less ▲]

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See detailDifferential Functionalities of Amphiphilic Peptide Segments of the Cell-Septation Penicillin-Binding Protein 3 of Escherichia Coli
Marrec-Fairley, Monique; Piette, André ULg; Gallet, Xavier et al

in Molecular Microbiology (2000), 37(5), 1019-1031

The class B M1-V577 penicillin-binding protein (PBP) 3 of Escherichia coli consists of a M1-L39 membrane anchor (bearing a cytosolic tail) that is linked via a G40-S70 intervening peptide to an R71-I236 ... [more ▼]

The class B M1-V577 penicillin-binding protein (PBP) 3 of Escherichia coli consists of a M1-L39 membrane anchor (bearing a cytosolic tail) that is linked via a G40-S70 intervening peptide to an R71-I236 non-catalytic module (containing the conserved motifs 1-3) itself linked via motif 4 to a D237-V577 catalytic module (containing the conserved motifs 5-7 of the penicilloyl serine transferases superfamily). It has been proposed that during cell septation the peptidoglycan crosslinking activity of the acyl transferase module of PBP3 is regulated by the associated M1-I236 polypeptide itself in interaction with other components of the divisome. The fold adopted by the R71-V577 polypeptide of PBP3 has been modelled by reference to the corresponding R76-S634 polypeptide of the class B Streptococcus pneumoniae PBP2x. Based on these data and the results of site-directed mutagenesis of motifs 1-3 and of peptide segments of high amphiphilicity (identified from hydrophobic moment plots), the M1-I236 polypeptide of PBP3 appears to be precisely designed to work in the way proposed. The membrane anchor and the G40-S70 sequence (containing the G57-Q66 peptide segment) upstream from the non-catalytic module have the information ensuring that PBP3 undergoes proper insertion within the divisome at the cell septation site. Motif 1 and the I74-L82 overlapping peptide segment, motif 2 and the H160-G172 overlapping peptide segment, and the G188-D197 motif 3 are located at or close to the intermodule junction. They contain the information ensuring that PBP3 folds correctly and the acyl transferase catalytic centre adopts the active configuration. The E206-V217 peptide segment is exposed at the surface of the non-catalytic module. It has the information ensuring that PBP3 fulfils its cell septation activity within the fully complemented divisome. [less ▲]

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See detailEstradiol Pharmacokinetics after Transdermal Application of Patches to Postmenopausal Women: Matrix Versus Reservoir Patches
Reginster, Jean-Yves ULg; Donazzolo, Y.; Brion, N. et al

in Climacteric : The Journal of the International Menopause Society (2000), 3(3), 168-75

OBJECTIVE: A new matrix 17 beta-estradiol transdermal patch incorporating lauric acid to improve estradiol skin absorption has been designed for hormone replacement therapy. Estradiol pharmacokinetics ... [more ▼]

OBJECTIVE: A new matrix 17 beta-estradiol transdermal patch incorporating lauric acid to improve estradiol skin absorption has been designed for hormone replacement therapy. Estradiol pharmacokinetics obtained with the prototype, its industrial counterpart, a matrix-type, System 50, and a reservoir-type, Estraderm TTS 50, transdermal patch have been compared. Each device delivers 50 micrograms estradiol daily. METHODS: Twenty postmenopausal women received each of the four formulations for 3 days in a Latin-square design and with a minimum 4-day wash-out period between treatments. Estradiol plasma concentrations were measured by radioimmunoassay at 6, 12, 24, 48 and 72 h after application. RESULTS: The prototype patch and its industrial counterpart showed no significant difference in estradiol delivery, with 72-h systemic exposure to estradiol similar to that of the reservoir patch but greater than that of the reference matrix formulation, with average baseline-corrected concentrations (SEM) of 35 (4), 32 (3), 32 (2) and 19 (1.8) pg/ml, respectively. In addition, they ensured more stable delivery, with coefficients of variation of plasma estradiol concentrations (12-72 h) of 29, 41, 63 and 84%, respectively. All matrix patches demonstrated the same patients to be poor estradiol absorbers, different from those encountered with the reservoir patch type, despite an improved estradiol bioavailability with the lauric acid-containing matrix patch. CONCLUSION: Matrix patches incorporating lauric acid led to estradiol plasma levels more stable than with the reference matrix and reservoir patches, and greater than those with the reference matrix patch. [less ▲]

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See detailDetermination of the Enantiomers of 3-Tert.-Butylamino-1,2-Propanediol by High-Performance Liquid Chromatography Coupled to Evaporative Light Scattering Detection
Toussaint, B.; Duchateau, A. L.; van der Wal, S. et al

in Journal of Chromatography. A (2000), 890(2), 239-49

A method for the separation and quantitation of the enantiomers of 3-tert.-butylamino-1,2-propanediol by high-performance liquid chromatography and evaporative light scattering detection has been ... [more ▼]

A method for the separation and quantitation of the enantiomers of 3-tert.-butylamino-1,2-propanediol by high-performance liquid chromatography and evaporative light scattering detection has been developed. Separation of the enantiomers was performed in normal-phase liquid chromatography on a Chiralpak AS chiral stationary phase. The influence of the gas nature, gas pressure and temperature of the drift tube of the evaporative light scattering detector on the detection sensitivity was investigated. The method was validated in terms of linearity, limit of quantitation, accuracy and precision. The enantiomeric excess of (S)-3-tert.-butylamino-1,2-propanediol, used for the industrial synthesis of (S)-timolol, was measured from 0 to 94%. [less ▲]

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See detailLeptin Effects on Pulsatile Gonadotropin Releasing Hormone Secretion from the Adult Rat Hypothalamus and Interaction with Cocaine and Amphetamine Regulated Transcript Peptide and Neuropeptide Y
Parent, Anne-Simone ULg; LEBRETHON, Marie-Christine ULg; Gerard, Arlette ULg et al

in Regulatory Peptides (2000), 92(1-3), 17-24

Leptin may act as a negative feedback signal to the hypothalamic control of appetite through suppression of neuropeptide Y (NPY) secretion and stimulation of cocaine and amphetamine regulated transcript ... [more ▼]

Leptin may act as a negative feedback signal to the hypothalamic control of appetite through suppression of neuropeptide Y (NPY) secretion and stimulation of cocaine and amphetamine regulated transcript (CART). We aimed at studying the effects of leptin, CART and NPY on the hypothalamic control of the pituitary-gonadal system. Pulsatile gonadotropin-releasing hormone (GnRH) secretion was studied in vitro using retrochiasmatic hypothalamic explants from adult rats. In the female, GnRH pulse amplitude was significantly increased by leptin (10(-7) M) and CART (10(-6) M) irrespective of the estrus cycle phase while no such effects were seen in the male. The GnRH interpulse interval was not affected in both sexes. Passive immunoneutralization against CART caused a reduction in GnRH pulse amplitude in the female. A slight but significant increase in GnRH pulse amplitude was caused by NPY (10(-7) M) in the female. However, GnRH pulse amplitude was not affected by a Y5-receptor antagonist (10(-6) M) while the interpulse interval was significantly increased as shown previously in the male. The increase in GnRH pulse amplitude caused by leptin was totally prevented by coincubation with an anti-CART antiserum whereas it was not affected by coincubation with the NPY Y5-receptor antagonist (10(-7) M). In conclusion, leptin and NPY show separate permissive effects on GnRH secretion in the adult rat hypothalamus. In both sexes, NPY is prominently involved in the control of the frequency of pulsatile GnRH secretion through the Y5 receptor subtype. Leptin causes a female-specific facilitatory effect on GnRH pulse amplitude which is mediated by CART and which occurs irrespective of the estrus cycle phase. [less ▲]

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See detailAggregates formed by amphoteric diblock copolymers in water
Gohy, Jean-François; Creutz, Serge; Garcia, Myriam et al

in Macromolecules (2000), 33(17), 6378-6387

The associating behavior of a series of monodisperse poly(2-(dimethylamino)ethyl methacrylate)-b-poly(methacrylic acid) (PDMAEMA-b-PMAA) ampholytic diblock copolymers has been studied in water in the ... [more ▼]

The associating behavior of a series of monodisperse poly(2-(dimethylamino)ethyl methacrylate)-b-poly(methacrylic acid) (PDMAEMA-b-PMAA) ampholytic diblock copolymers has been studied in water in the dilute regime as a function of pH and salt concentration. Dynamic light scattering (DLS) has been used to monitor the association behavior and transmission electron microscopy (TEM) to visualize the morphology of the aggregates. At and around the isoelectric point (IEP) of the ampholytic diblocks, strong electrostatic interactions occur and lead to the formation of insoluble complexes between negatively and positively charged blocks. These electrostatic interactions can be screened by the addition of salt, which leads to the partial dissolution of the material, according to Debye screening. For samples containing a major PDMAEMA block, spherical micelles are observed below the IEP. These micelles consist of a PMAA core surrounded by a water-soluble protonated PDMAEMA corona. At and above the IEP, these samples are insoluble. Spherical micelles are also formed below the IEP for samples containing a minor PDMAEMA block. These copolymers are insoluble at and around the IEP, whereas solubility is observed above the IEP with formation of aggregates of remarkable morphologies, including hollow spheres and complex compartmentalized aggregates. This aggregation is most favorable at high pH, and it cannot be accounted for only by electrostatic interaction between oppositely charged blocks. Indeed, short-range hydrophobic interaction between uncharged PDMAEMA blocks seems to play a key role in the association process. This is emphasized by quaternized poly(2-(dimethylamino)ethyl methacrylate)-b-poly(methacrylic acid) ampholytic copolymers which are carrying a permanent positive charge on the aminated monomeric units and do not form these particular aggregates. [less ▲]

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See detailReactive compatibilization of SAN/EPR blends. 1. Dependence of the phase morphology development on the reaction kinetics
Pagnoulle, Christophe; Koning, Cor; Leemans, Luc et al

in Macromolecules (2000), 33(17), 6275-6283

SAN containing 20 wt % of reactive SAN-X has been melt blended with EPDM containing 50 wt % of EP chains grafted by maleic anhydride (EP-g-MA). Two types of reactive groups (X) have been attached to SAN ... [more ▼]

SAN containing 20 wt % of reactive SAN-X has been melt blended with EPDM containing 50 wt % of EP chains grafted by maleic anhydride (EP-g-MA). Two types of reactive groups (X) have been attached to SAN (2 mol % of X), i.e., a primary amine and a precursor of it at the processing temperature, i.e., a carbamate. The SAN/rubber weight composition was kept constant at 75/25. The development of the phase morphology from pellet-sized rubber particles to dispersed submicrometer droplets has been investigated during reactive mixing for the two types of reactive SAN and has been found to depend on the interpolymer reaction rate and thus on the relative reactivity of the amine and the carbamate groups attached to SAN toward the maleic anhydride function of EP. [less ▲]

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See detailSmall-angle neutron scattering studies of low-polarity telechelic ionomer solutions. 3. Temperature dependence of the ionic association
Karayianni, Eleni; Jérôme, Robert ULg; Cooper, Stuart L

in Macromolecules (2000), 33(17), 6473-6484

The effect of temperature on the structure and single chain conformation of associating solutions of carboxy−telechelic polystyrene ionomers has been investigated in the dilute to semidilute concentration ... [more ▼]

The effect of temperature on the structure and single chain conformation of associating solutions of carboxy−telechelic polystyrene ionomers has been investigated in the dilute to semidilute concentration regime using the technique of small-angle neutron scattering. By applying different labeling methods, the temperature dependence of both the total scattering and single chain scattering functions was obtained independently. It was observed that temperature has a significant impact on the structure of the ionomer aggregates. Increasing temperature results in dissociation of the aggregated particles and the formation of smaller size multimers. Interestingly, the extent to which the multimers dissociate at a specific temperature compared to their initial state at room temperature is independent of concentration or ionic level, which indicates that it is independent of the degree of aggregation of particles. This leads to the conclusion that the apparent degree of aggregation can be controlled independently by concentration and temperature. For all systems studied the multimers formed through the ionic association keep an extended configuration over all the temperatures investigated. The Flory−Huggins polymer−solvent interaction parameter of the ionomer solutions showed only a slight decrease with increasing temperature. Despite the significant effect of temperature on the multimer structure, temperature was not observed to influence the single chain dimensions of the ionomer solutions. It was observed that the single chain dimensions remained unchanged over the range of variables studied. On the basis of these results, it is proposed that dissociation of the multimers takes place by disruption of the configuration of only a small number of bridging chains which connect different ionic clusters without influencing the main architecture of the associating structure. [less ▲]

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See detailTuning of the exchange dynamics of unimers between block copolymer micelles with temperature, cosolvents, and cosurfactants
van Stam, Jan; Creutz, Serge; De Schryver, Frans C et al

in Macromolecules (2000), 33(17), 6388-6395

The dynamics of unimer exchange between aqueous micelles, formed by two amphiphilic block copolymers, i.e., poly(styrene-b-sodium methacrylate) and poly(tert-butylstyrene-b-sodium methacrylate), has been ... [more ▼]

The dynamics of unimer exchange between aqueous micelles, formed by two amphiphilic block copolymers, i.e., poly(styrene-b-sodium methacrylate) and poly(tert-butylstyrene-b-sodium methacrylate), has been investigated by steady-state fluorescence spectroscopy. The kinetics are so slow at room temperature that no exchange could be detected over several hours, while at 60 °C the exchange rate constants could be estimated. These results corroborate our previous findings that the rate is slowed down by increasing the hydrophobicity of the core. In addition to the temperature, the exchange can also be tuned by the addition of either a cosolvent or a cosurfactant. The efficiency of these additives to speed up the exchange process is related to their water solubility and their compatibility with the hydrophobic core of the micelles. The most pronounced effect on the exchange process is observed when the water solubility is low and the mixing of the additive with the hydrophobic core is favorable. [less ▲]

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See detailRadial Glia Phenotype: Origin, Regulation, and Transdifferentiation
Chanas-Sacre, Grazyna; Rogister, Bernard ULg; Moonen, Gustave ULg et al

in Journal of Neuroscience Research (2000), 61(4), 357-63

Radial glial cells play a major guidance role for migrating neurons during central nervous system (CNS) histogenesis but also play many other crucial roles in early brain development. Being among the ... [more ▼]

Radial glial cells play a major guidance role for migrating neurons during central nervous system (CNS) histogenesis but also play many other crucial roles in early brain development. Being among the earliest cells to differentiate in the early CNS, they provide support for neuronal migration during embryonic brain development; provide instructive and neurotrophic signals required for the survival, proliferation, and differentiation of neurons; and may be multipotential progenitor cells that give rise to various cell types, including neurons. Radial glial cells constitute a major cell type of the developing brain in numerous nonmammalian and mammalian vertebrates, increasing in complexity in parallel with the organization of the nervous tissue they help to build. In mammalian species, these cells transdifferentiate into astrocytes when neuronal migration is completed, whereas, in nonmammalian species, they persist into adulthood as a radial component of astroglia. Thus, our perception of radial glia may have to change from that of path-defining cells to that of specialized precursor cells transiently fulfilling a guidance role during brain histogenesis. In that respect, their apparent change of phenotype from radial fiber to astrocyte probably constitutes one of the most common transdifferentiation events in mammalian development. [less ▲]

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