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See detailEffects of low dose endosulfan exposure on brain neurotransmitter levels in the African clawed frog Xenopus laevis
Preud'Homme, Valérie; Milla, Sylvain; Gillardin, Virginie et al

in Chemosphere (2015), 120(2), 357-364

Understanding the impact of pesticides in amphibians is of growing concern to assess the causes of their decline. Among pesticides, endosulfan belongs to one of the potential sources of danger because of ... [more ▼]

Understanding the impact of pesticides in amphibians is of growing concern to assess the causes of their decline. Among pesticides, endosulfan belongs to one of the potential sources of danger because of its wide use and known effects, particularly neurotoxic, on a variety of organisms. However, the effect of endosulfan was not yet evaluated on amphibians at levels encompassing simultaneously brain neurotransmitters and behavioural endpoints. In this context, tadpoles of the African clawed frog Xenopus laevis were submitted to four treatments during 27 d: one control, one ethanol control, and two low environmental concentrations of endosulfan (0.1 and 1 μg L−1). Endosulfan induced a significant increase of brain serotonin level at both concentrations and a significant increase of brain dopamine and GABA levels at the lower exposure but acetylcholinesterase activity was not modified by the treatment. The gene coding for the GABA transporter 1 was up-regulated in endosulfan contaminated tadpoles while the expression of other genes coding for the neurotransmitter receptors or for the enzymes involved in their metabolic pathways was not significantly modified by endosulfan exposure. Endosulfan also affected foraging, and locomotion in links with the results of the physiological assays, but no effects were seen on growth. These results show that low environmental concentrations of endosulfan can induce adverse responses in X. laevis tadpoles. At a broader perspective, this suggests that more research using and linking multiple markers should be used to understand the complex mode of action of pollutants. [less ▲]

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See detailEffects of Macrophage Transplantation in the Injured Adult Rat Spinal Cord: A Combined Immunocytochemical and Biochemical Study
Franzen, Rachelle ULg; Schoenen, Jean ULg; Leprince, Pierre ULg et al

in Journal of Neuroscience Research (1998), 51(3), 316-27

Early and robust invasion by macrophages may be one of the reasons why axonal regeneration is more effective in the PNS than in the CNS. Therefore, we have grafted autologous peritoneal macrophages ... [more ▼]

Early and robust invasion by macrophages may be one of the reasons why axonal regeneration is more effective in the PNS than in the CNS. Therefore, we have grafted autologous peritoneal macrophages labeled with fluorescent latex microspheres into spinal cord compression lesions. At various survival times, we have studied their effect on the expression of neuronal (neurofilaments [NF], calcitonin gene-related peptide [CGRP], 5-hydroxytryptamine [5-HT]) and nonneuronal markers (myelin-associated glycoprotein [MAG], glial fibrillary acidic protein [GFAP], laminin) by using semiquantitative Western blot and immunohistochemical techniques. After 1 month, we observed a significant decrease of the expression of MAG as well as an important invasion of the lesion site by neurites, chiefly peptidergic axons of presumed dorsal root origin, in macrophage-grafted animals compared with controls. In addition, angiogenesis and Schwann cell infiltration were more pronounced after macrophage grafts, providing an increase in laminin, a favorable substrate for axonal regrowth. By using reverse transcription-polymerase chain reaction (RT-PCR), mRNAs for tumor necrosis factor-alpha (TNF-alpha) were detected in the transplanted cells, whereas results were negative for nerve growth factor (NGF), neurotrophin-3 (NT-3), brain-derived neurotrophic factor (BDNF), or acidic fibroblast growth factor (aFGF) and basic fibroblast growth factor (bFGF). Thus, macrophage grafts may represent an interesting strategy to promote axonal regeneration in the CNS. Our study suggests that they may exert their beneficial effects by degrading myelin products, which inhibit axonal regrowth, and by promoting a permissive extracellular matrix containing notably laminin. No evidence for a direct synthesis of neurotrophic factors by the transplanted macrophages was found in this study, but resident glial cells could secrete such factors as a result of stimulation by macrophage-released cytokines. [less ▲]

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See detailEffects of management of nitrogen fertilizers and conversion of cropping soils in fallow on nitrate pollution studie of the springs of roodt (Nospelt, Luxembourg).
Weinzaepflen, Emmanuelle; Vander Borght, Paul ULg; Tychon, Bernard ULg

in Conference proceedings 3rd international conference on diffuse pollution (1998)

A management of nitrogen fertilizers and a conversion of cropping soil into fallow were developed to reduce the nitrate pollution of spring exploit to supply with drinking water the southwestern ... [more ▼]

A management of nitrogen fertilizers and a conversion of cropping soil into fallow were developed to reduce the nitrate pollution of spring exploit to supply with drinking water the southwestern Luxembourg. The methodological approach was based on in situ observations and includes a study of nitrates lost by leaching (measure of nitrogen profiles in experimental fields, use of vertical soil water cup ceramics) and study of the water quality of springs (measurements of nitrate concentrations). Since October 1995, the nitrate concentrations of polluted springs have been reduced by 25 mg l-1 due to the fallow and the reduction of nitrogen fertilizers. [less ▲]

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See detailEffects of management regimes and extreme climatic events on plant population viability in Eryngium alpinum
Andrello, Marco; Bizoux, Jean-Philippe ULg; BARBET-MASSIN, morgane et al

in Biological Conservation (2012), 147(1), 99-106

Extreme climatic events like the 2003 summer heatwave and inappropriate land management can threaten the existence of rare plants. We studied the response of Eryngium alpinum, a vulnerable species, to ... [more ▼]

Extreme climatic events like the 2003 summer heatwave and inappropriate land management can threaten the existence of rare plants. We studied the response of Eryngium alpinum, a vulnerable species, to this extreme climatic event and different agricultural practices. A demographic study was conducted in seven field sites between 2001 and 2010. Stage-specific vital rates were used to parameterize matrix population models and perform stochastic projections to calculate population growth rates and estimate extinction probabilities. Among management regimes, spring grazing and land abandonment decreased vital rates and population growth, while autumn grazing and late mowing had positive effects on population viability. The 2003 heatwave reduced fecundity rates and survival rates. Only spring grazed sites presented considerable extinction risk. Stochastic projections showed that an increased frequency of 2003-like events may exacerbate extinction risk, but extinction probability depends mainly on land management regimes. To better conserve E. alpinum populations, we recommend conversion of presently spring grazed and abandoned sites to late mowing or autumn grazing. [less ▲]

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See detailEffects of manganese addition on carbon release from forest floor horizons
Trum, Florence; Titeux, Hugues; Cornelis, Jean-Thomas ULg et al

in Canadian Journal of Forest Research = Journal Canadien de la Recherche Forestière (2011), 41(3),

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See detailEffects of mannose and mannose derivatives on the clearance of IgG antibody-coated erythrocytes in the rat
Malaise, Michel ULg; Hoyoux, C.; Franchimont, P. et al

in Immunology (1989), 68(1), 126-132

The effects of D-mannose, mannose dimers, mannan, or lactotransferrin [a glycoprotein containing mannose alpha-(1,6) linkages] infusion on the clearance of IgG-coated, 99mTc-labelled, autologous red blood ... [more ▼]

The effects of D-mannose, mannose dimers, mannan, or lactotransferrin [a glycoprotein containing mannose alpha-(1,6) linkages] infusion on the clearance of IgG-coated, 99mTc-labelled, autologous red blood cells (IgG-RBC) by the spleen and liver were investigated in the rat. Untreated autologous rat RBC labelled with 111In were simultaneously injected to correct for 99mTc present in the blood contained in each organ. In normal rats, the mean specific spleen uptake (per g) of IgG-RBC was about 10 times higher than the mean specific liver uptake (per g). Consistent with the clearance curves of IgG-RBC, the mean specific splenic uptake of those RBC significantly decreased after D-mannose, mannose dimers, mannan, or lactotransferrin injections, compared with that measured in normal rats or in control rats receiving i.v. physiological saline, 5% or 15% glucose. In contrast, the mean specific liver uptake of IgG-RBC remained unchanged under otherwise identical experimental conditions. The splenic blockade induced by mannan and mannose derivatives was dose-dependent, C3-independent and spontaneously reversible within 42 hr. Splenic macrophages isolated from mannose- or mannan-treated animals expressed a decreased receptor activity for the Fc domain of IgG, whereas no consistent effect on the C3 receptors was noted. These data show a transient and specific impairment of the Fc(IgG)-receptor function of rat splenic macrophages after the i.v. injection of D-mannose or of mannose derivatives. They support the concept that simple sugar compounds can exhibit immunoregulatory activities in vivo, as has been already shown in vitro. [less ▲]

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See detailEffects of marginal iron overload on iron homeostasis and immune function in alveolar macrophages isolated from pregnant and normal rats.
Ward, Roberta J; Wilmet, Stephanie; Legssyer, Rachida et al

in Biometals (2009), 22(2), 211-23

The effects of changes in macrophage iron status, induced by single or multiple iron injections, iron depletion or pregnancy, on both immune function and mRNA expression of genes involved in iron influx ... [more ▼]

The effects of changes in macrophage iron status, induced by single or multiple iron injections, iron depletion or pregnancy, on both immune function and mRNA expression of genes involved in iron influx and egress have been evaluated. Macrophages isolated from iron deficient rats, or pregnant rats at day 21 of gestation, either supplemented with a single dose of iron dextran, 10 mg, at the commencement of pregnancy, or not, showed significant increases of macrophage ferroportin mRNA expression, which was paralleled by significant decreases in hepatic Hamp mRNA expression. IRP activity in macrophages was not significantly altered by iron status or the inducement of pregnancy +/- a single iron supplement. Macrophage immune function was significantly altered by iron supplementation and pregnancy. Iron supplementation, alone or combined with pregnancy, increased the activities of both NADPH oxidase and nuclear factor kappa B (NFkappaB). In contrast, the imposition of pregnancy reduced the ability of these parameters to respond to an inflammatory stimuli. Increasing iron status, if only marginally, will reduce the ability of macrophages to mount a sustained response to inflammation as well as altering iron homeostatic mechanisms. [less ▲]

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See detailEffects of marrow grafting on preleukemia cells and thymic nurse cells in C57BL/Ka mice after a leukemogenic split-dose irradiation.
Defresne, Marie-Paule ULg; Greimers, Roland ULg; Lenaerts, Patrick et al

in Journal of the National Cancer Institute (1986), 77(5), 1079-85

A split-dose regimen of whole-body irradiation (4 X 175 rad at weekly intervals) induced thymic lymphomas in C57BL/Ka mice after a latent period of 3-9 months. Meanwhile, preleukemia cells arose in the ... [more ▼]

A split-dose regimen of whole-body irradiation (4 X 175 rad at weekly intervals) induced thymic lymphomas in C57BL/Ka mice after a latent period of 3-9 months. Meanwhile, preleukemia cells arose in the thymus and bone marrow and persisted until the onset of lymphomas. Simultaneously, thymic lymphopoiesis was impaired; thymocyte numbers were subnormal and thymic nurse cells disappeared in a progressive but irreversible fashion. The depletion of these lymphoepithelial complexes, which are normally involved in the early steps of thymic lymphopoiesis, was related to altered prothymocyte activity in bone marrow and to damaged thymic microenvironment, perhaps as a consequence of the presence of preleukemia cells. The grafting of normal bone marrow cells after irradiation prevented the development of lymphomas. However, marrow reconstitution did not inhibit the induction of preleukemia cells. They disappeared from the thymus during the second part of the latent period. At the same time, thymic lymphopoiesis was restored; thymocytes and nurse cell numbers returned to normal as a consequence of the proliferation of grafted marrow-derived cells within the thymus. The results thus demonstrated an intimate relationship between preleukemia cells and an alteration of thymic lymphopoiesis, which particularly involved the nurse cell microenvironment. Some preleukemia cells in marrow-reconstituted, irradiated mice derived from the unirradiated marrow inoculate. Thus these cells acquired neoplastic potential through a factor present in the irradiated tissues. The nature of this indirect mechanism was briefly discussed. [less ▲]

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See detailEffects of melody and technique on acoustical and musical features of Western operatic singing voices
Larrouy, Pauline ULg; Magis, David ULg; Morsomme, Dominique ULg

in Journal of Voice (2014)

Objective: The operatic singing technique is frequently employed in classical music. Several acoustical parameters of this specific technique have been studied but how these parameters combine remains ... [more ▼]

Objective: The operatic singing technique is frequently employed in classical music. Several acoustical parameters of this specific technique have been studied but how these parameters combine remains unclear. This study aims to further characterize the Western operatic singing technique by observing the effects of melody and technique on acoustical and musical parameters of the singing voice. Methods: Fifty professional singers performed two contrasting melodies (popular song and romantic melody) with two vocal techniques (with and without operatic singing technique). The common quality parameters (energy distribution, vibrato rate and extent), perturbation parameters (standard deviation of the fundamental frequency, signal-to-noise ratio, jitter and shimmer) and musical features (fundamental frequency of the starting note, average tempo, and sound pressure level) of the 200 sung performances were analyzed. Results: The results regarding the effect of melody and technique on the acoustical and musical parameters show that the choice of melody had a limited impact on the parameters observed, whereas a particular vocal profile appeared depending on the vocal technique employed. Conclusions: This study confirms that vocal technique affects most of the parameters examined. In addition, the observation of quality, perturbation and musical parameters contributes to a better understanding of the Western operatic singing technique. [less ▲]

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See detailEffects of meloxicam compared to acetylsalicylic acid in human articular chondrocytes
Bassleer, Corinne; Magotteaux, Jacques ULg; Geenen, Vincent ULg et al

in Pharmacology (1997), 54

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See detailEffects of metabolism inhibitors, antiestrogens and antiandrogens on the androgen and estrogen induced sexual behavior in Japanese quail.
Alexandre, Corine; Balthazart, Jacques ULg

in Physiology & Behavior (1986), 38(4), 581-91

The relative contribution of androgenic and estrogenic metabolites of testosterone to the activation of sexual behavior was studied in Japanese quail by using inhibitors of testosterone metabolism ... [more ▼]

The relative contribution of androgenic and estrogenic metabolites of testosterone to the activation of sexual behavior was studied in Japanese quail by using inhibitors of testosterone metabolism, antiestrogens and antiandrogens. These compounds were tested in castrated birds whose sexual behavior had been activated by silastic implants of testosterone (T) or daily injections of testosterone propionate (TP) or diethylstilboestrol (DES). The aromatase inhibitor ATD only depressed T-induced behavior when injected at high doses and the 5 alpha-reductase inhibitor, 4MA was inactive in this respect. The antiestrogens, tamoxifen (TAM) and nitromifene citrate (CI-628) strongly depressed sexual behavior but they also drastically reduced the crowing behavior which is typically androgen-dependent which throws some doubts on the specificity of their action. The antiandrogens, flutamide and cyproterone acetate (CA), only had limited inhibitory effects on the copulatory behavior but similarly decreased only marginally the crowing. As they strongly depressed the cloacal gland growth, it can be ascertained that they were injected in sufficient amounts and their lack of action on crowing questions the ability of these compounds to inhibit brain processes even when they are androgen-dependent. Taken together with the results of previous experiments which tested the behavioral effects of the testosterone metabolites, the present data confirm the implication of both androgenic and estrogenic metabolites of testosterone in the activation of behavior. Their interaction remains, however, poorly defined and its understanding will probably require the identification of the biochemical processes which in the brain mediate the behavior. [less ▲]

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See detailEffects of metals on mouse B16 melanoma and 3T3 fibroblasts
Siwek, Brigitte; Bahbouth, E; Gillet, Marie-Claire ULg et al

Poster (1990, October)

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See detailEffects of methane on giant planet’s UV emissions and implications for the auroral characteristics
Gustin, Jacques ULg; Gérard, Jean-Claude; Grodent, Denis ULg et al

in Journal of Molecular Spectroscopy (2013)

This study reviews methods used to determine important characteristics of giant planet’s UV aurora (brightness,energy of the precipitating particles, altitude of the emission peak,. . .), based on the ... [more ▼]

This study reviews methods used to determine important characteristics of giant planet’s UV aurora (brightness,energy of the precipitating particles, altitude of the emission peak,. . .), based on the absorbing properties of methane and other hydrocarbons. Ultraviolet aurorae on giant planets are mostly caused by inelastic collisions between energetic magnetospheric electrons and the ambient atmospheric H2 molecules. The auroral emission is situated close to a hydrocarbon layer and may be attenuated by methane (CH4), ethane (C2H6) and acetylene (C2H2) at selected wavelengths. As methane is the most abundant hydrocarbon, it is the main UV absorber and attenuates the auroral emission shorward of 1350 Å. The level of absorption is used to situate the altitude/pressure level of the aurora, hence the energy of the precipitated electrons, whose penetration depth is directly related to their mean energy. Several techniques are used to determine these characteristics, from the color ratio method which measures the level of absorption from the ratio between an absorbed and an unabsorbed portion of the observed auroral spectrum, to more realistic methods which combine theoretical distributions of the precipitating electrons with altitude dependent atmospheric models. The latter models are coupled with synthetic or laboratory H2 spectra and the simulated emergent spectra are compared to observations to determine the best auroral characteristics. Although auroral characteristics may be very variable with time and locations, several typical properties may be highlighted from these methods: the Jovian aurora is the most powerful, with brightness around 120 kR produced by electrons of mean energy 100 keV and an emission situated near the 1 lbar level ( 250 km above the 1 bar level) while Saturn’s aurora is fainter ( 10 kR), produced by electrons less than 20 keV and situated near the 0.2 lbar level ( 1100 km). [less ▲]

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See detailEffects of methionine sources in interaction with dietary protein content on performance and oxidative status of broiler chickens
Swennen, Q.; Buyse, Johan; Mercier, Yves et al

Poster (2010)

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See detailEffects of micellar adsorption on the photosensitizing properties of xanthènes dyes
Hoebeke, Maryse ULg; Gandin, Ezio; Decuyper, Jean et al

in Journal of photochemistry (1986), 35

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