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See detailRapid And Homogenous Detection Of Apple Stem Pitting Virus By Rt-Pcr And A Fluorogenic 3 ' Minor Groove Binder-Dna Probe
Salmon, Marc ULg; Vendrame, Marina; Kummert, Jean et al

in European Journal of Plant Pathology (2002), 108(8), 755-762

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See detailRapid and Reversible Inhibition of Brain Aromatase Activity
Balthazart, Jacques ULg; Baillien, M.; Ball, G. F.

in Journal of Neuroendocrinology (2001), 13(1), 63-73

Many actions of androgens require their conversion via the enzyme aromatase into oestrogens. Changes in brain aromatase activity are thought to take place via changes in enzyme concentration mediated by ... [more ▼]

Many actions of androgens require their conversion via the enzyme aromatase into oestrogens. Changes in brain aromatase activity are thought to take place via changes in enzyme concentration mediated by effects of sex steroids on aromatase transcription. These changes are relatively slow which fits in well with the fact that oestrogens are generally viewed as slow-acting messengers that act via changes in gene transcription. More recently, fast actions of oestrogens, presumably at the level of the cell membrane, have been described both in the female brain and in the male brain after the conversion of testosterone to oestradiol. It is difficult to reconcile the slow regulation of oestrogen synthesis (that occurs via changes in aromatase concentration) with a rapid action at the membrane level. Even if fast transduction mechanisms are available, this will not result in rapid changes in brain function if the availability of the ligand does not also change rapidly. Here, we report that aromatase activity in neural tissue of male Japanese quail (Coturnix japonica) is rapidly downregulated in the presence of Mg(2+), Ca(2+) and ATP in hypothalamic homogenates and in brain explants exposed to high Ca(2+) levels following a K(+)-induced depolarization or the stimulation of glutamate receptors. The K(+)-induced inhibition of aromatase activity is observed within minutes and reversible. Given that aromatase is present in presynaptic boutons, it is possible that rapidly changing levels of locally produced oestrogen are available for nongenomic regulation of neuronal physiology in a manner more akin to the action of a neuropeptide than previously hypothesized. [less ▲]

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See detailRapid and Selective Isolation of Follicular Dendritic Cells by Low Speed Centrifugations on Discontinuous Bsa Gradients
Marcoty, C.; Heinen, Ernst ULg; Antoine, Nadine ULg et al

in Advances in Experimental Medicine and Biology (1993), 329

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See detailRapid and sustained anti-fracture efficacy of strontium ranelate in postmenopausal osteoporosis
Reginster, Jean-Yves ULg; Sawicki, A.; Devogelaer, Jean-Pierre et al

in Arthritis and Rheumatism (2002, September), 46(number 9 (suppl.)), 584-5

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See detailRapid and sustained effects of risedronate in reducting hip fracture risk in elderly women with osteoporis
Seeman, E; McClung, M; Zippel, H et al

in Journal of Bone and Mineral Research (2000), 15(S1), 149

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See detailRapid and sustained hip fracture risk reduction with risedronate in elderly women with osteoporosis
Cooper, C; Reginster, Jean-Yves ULg; McClung, M et al

in BONE (2001), S28

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See detailRapid Ca2+ influx via the platelet P2X1 ion channel requires its N- and C-terminal tyrosine phosphorylation.
Oury, Cécile ULg; Toth-Zsamboki, Emese; Nilius, Bernd et al

in Thrombosis and Haemostasis (2001)

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See detailRapid changes in production and behavioral action of estrogens
Balthazart, Jacques ULg; Baillien, Michelle; Charlier, Thierry ULg et al

in Trabajos del Instituto Cajal (2005), 80

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See detailRapid changes in production and behavioral action of estrogens.
Balthazart, Jacques ULg; Cornil, Charlotte ULg; Taziaux, Mélanie ULg et al

in Neuroscience (2006), 138(3), 783-91

It is well established that sex steroid hormones bind to nuclear receptors, which then act as transcription factors to control brain sexual differentiation and the activation of sexual behaviors ... [more ▼]

It is well established that sex steroid hormones bind to nuclear receptors, which then act as transcription factors to control brain sexual differentiation and the activation of sexual behaviors. Estrogens locally produced in the brain exert their behavioral effects in this way but mounting evidence indicates that estrogens also can influence brain functioning more rapidly via non-genomic mechanisms. We recently reported that, in Japanese quail, the activity of preoptic estrogen synthase (aromatase) can be modulated quite rapidly (within minutes) by non-genomic mechanisms, including calcium-dependent phosphorylations. Behavioral studies further demonstrated that rapid changes in estrogen bioavailability, resulting either from a single injection of a high dose of estradiol or from the acute inhibition of aromatase activity, significantly affect the expression of both appetitive and consummatory aspects of male sexual behavior with latencies ranging between 15 and 30 min. Together these data indicate that the bioavailability of estrogens in the brain can change on different time-scales (long- and short-term) that match well with the genomic and non-genomic actions of this steroid and underlie two complementary mechanisms through which estrogens modulate behavior. Estrogens produced locally in the brain should therefore be considered not only as neuroactive steroids but they also display many (if not all) functional characteristics of neuromodulators and perhaps neurotransmitters. [less ▲]

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See detailRapid changes of aromatase activity in discrete brain regions following social interactions
de Bournonville, Catherine ULg; Ball, Gregory, F.; Balthazart, Jacques ULg et al

in Trabajos del Instituto Cajal (2011), LXXXIII

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See detailRapid Collapse into a Molten Globule Is Followed by Simple Two-State Kinetics in the Folding of Lysozyme from Bacteriophage lambda
Di Paolo, Alexandre ULg; Balbeur, D.; De Pauw, Edwin ULg et al

in Biochemistry (2010), 49

Stopped-flow fluorescence and circular dichroism spectroscopy have been used in combination with quenched-flow hydrogen exchange labeling, monitored by two-dimensional NMR and electrospray ionization mass ... [more ▼]

Stopped-flow fluorescence and circular dichroism spectroscopy have been used in combination with quenched-flow hydrogen exchange labeling, monitored by two-dimensional NMR and electrospray ionization mass spectrometry, to investigate the folding kinetics of lysozyme from bacteriophage lambda (lambda lysozyme) at pH 5.6, 20 degrees C. The first step in the folding of lambda lysozyme occurs very rapidly (tau < 1 ms) after refolding is initiated and involves both hydrophobic collapse and formation of a high content of secondary structure but only weak protection from (1)H/(2)H exchange and no fixed tertiary structure organization. This early folding step is reflected in the dead-time events observed in the far-UV CD and ANS fluorescence experiments. Following accumulation of this kinetic molten globule species, the secondary structural elements are stabilized and the majority (ca. 88%) of refolding molecules acquire native-like properties in a highly cooperative two-state process, with tau = 0.15 +/- 0.03 s. This is accompanied by the acquisition of substantial native-like protection from hydrogen exchange. A double-mixing experiment and the absence of a denaturant effect reveal that slow (tau = 5 +/- 1 s) folding of the remaining (ca. 12%) molecules is rate limited by the cis/trans isomerization of prolines that are trans in the folded enzyme. In addition, native state hydrogen exchange and classical denaturant unfolding experiments have been used to characterize the thermodynamic properties of the enzyme. In good agreement with previous crystallographic evidence, our results show that lambda lysozyme is a highly dynamic protein, with relatively low conformational stability (DeltaG degrees (N-U) = 25 +/- 2 kJ.mol(-1)). [less ▲]

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See detailRapid control of brain aromatase activity by glutamatergic inputs
Balthazart, Jacques ULg; Baillien, M.; Ball, G. F.

in Endocrinology (2006), 147(1), 359-366

Estrogens derived from the neural aromatization of testosterone play a key role in the activation of male sexual behavior in many vertebrates and have now been recognized to have rapid membrane effects on ... [more ▼]

Estrogens derived from the neural aromatization of testosterone play a key role in the activation of male sexual behavior in many vertebrates and have now been recognized to have rapid membrane effects on brain function. Such changes in aromatase activity and hence in local estrogen concentrations could rapidly modulate behavioral responses. We show here that there is a very rapid (within minutes) decrease in aromatase activity in quail hypothalamic explants exposed to treatments affecting intracellular Ca2+ concentrations, such as the addition of glutamate agonists (kainate, alpha-amino-3-hydroxymethyl-4-isoxazole propionic acid, and, to a much lesser extent, N-methyl-D-aspartate), but not of gamma-aminobutyric acid. The kainate effects, which reduce aromatase activity by 25-50%, are observed within 5 min, are completely blocked in explants exposed to specific kainate antagonists (6-cyano-7-nitroquinoxaline-2,3-dione disodium or 1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[f]quinoxaline-7-sulfonamide disodium), and are also rapidly reversible when effectors are washed out. Together, these data support the idea that the synthesis of estrogen can be rapidly regulated in the brain, thus producing rapid changes in local estrogen bioavailability that could rapidly modify brain function with a time course similar to what has previously been described for neurotransmitters and neuromodulators. [less ▲]

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See detailRapid control of male typical behaviors by brain-derived estrogens
Cornil, Charlotte ULg; Ball, Gregory F; Balthazart, Jacques ULg

in Frontiers in Neuroendocrinology (2012)

Beside their genomic mode of action, estrogens also activate a variety of cellular signaling pathways through non-genomic mechanisms. Until recently, little was known regarding the functional significance ... [more ▼]

Beside their genomic mode of action, estrogens also activate a variety of cellular signaling pathways through non-genomic mechanisms. Until recently, little was known regarding the functional significance of such actions in males and the mechanism that control local estrogen concentration with a spatial and time resolution compatible with these non-genomic actions had rarely been examined. Here, we review evidence that estrogens rapidly modulate a variety of behaviors in male vertebrates. Then, we present in vitro work supporting the existence of a control mechanism of local brain estrogen synthesis by aromatase along with in vivo evidence that rapid changes in aromatase activity also occur in a region-specific manner in response to changes in the social or environmental context. Finally, we suggest that the brain estrogen provision may also play a significant role in females. Together these data bolster the hypothesis that brain-derived estrogens should be considered as neuromodulators. [less ▲]

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See detailRapid control of reproductive behaviour by locally synthesised oestrogens: focus on aromatase.
Cornil, Charlotte ULg; Seredynski, Aurore ULg; de Bournonville, Catherine ULg et al

in Journal of Neuroendocrinology (in press)

Oestrogens activate nucleus- and membrane-initiated signalling. Nucleus-initiated events control a wide array of physiological and behavioural responses. These effects generally take place within ... [more ▼]

Oestrogens activate nucleus- and membrane-initiated signalling. Nucleus-initiated events control a wide array of physiological and behavioural responses. These effects generally take place within relatively long periods of time (several hours to days). By contrast, membrane-initiated signalling affects a multitude of cellular functions in a much shorter timeframe (seconds to minutes). However, much less is known about their functional significance. Furthermore, the origin of the oestrogens able to trigger these acute effects is rarely examined. Finally, these two distinct types of oestrogenic actions have often been studied independently such that we do not exactly know how they cooperate to control the same response. The present review presents a synthesis of recent work carried out in our laboratory that aimed to address these issues in the context of the study of male sexual behaviour in Japanese quail, which is a considered as a suitable species for tackling these issues. The first section presents data indicating that 17b-oestradiol, or its membrane impermeable analogues, acutely enhances measures of male sexual motivation but does not affect copulatory behaviour. These effects depend on the activation of membrane-initiated events and local oestrogen production. The second part of this review discusses the regulation of brain oestrogen synthesis through post-translational modifications of the enzyme aromatase. Initially discovered in vitro, these rapid and reversible enzymatic modulations occur in vivo following variations in the social and environment context and therefore provide a mechanism of acute regulation of local oestrogen provision with a spatial and time resolution compatible with the rapid effects observed on male sexual behaviour. Finally, we discuss how these distinct modes of oestrogenic action (membrane- versus nucleus-initiated) acting in different time frames (short- versus long-term) interact to control different components (motivation versus performance) of the same behavioural response and improve reproductive fitness. [less ▲]

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See detailRAPID DEACTIVATION OF N(2D) BY O - IMPACT ON THERMOSPHERIC AND MESOSPHERIC ODD NITROGEN
FESEN, C. G.; Gérard, Jean-Claude ULg; RUSCH, D. W.

in Journal of Geophysical Research. Space Physics (1989), 94(A5), 5419-5426

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See detailRapid decline of the CO2 buffering capacity in the North Sea and implications for the North Atlantic Ocean
Thomas, Helmuth; Prowe, A. E. Friederike; van Heuven, Steven et al

in Global Biogeochemical Cycles (2007), 21(GB4001),

New observations from the North Sea, a NW European shelf sea, show that between 2001 and 2005 the CO2 partial pressure (pCO2) in surface waters rose by 22 matm, thus faster than atmospheric pCO2, which in ... [more ▼]

New observations from the North Sea, a NW European shelf sea, show that between 2001 and 2005 the CO2 partial pressure (pCO2) in surface waters rose by 22 matm, thus faster than atmospheric pCO2, which in the same period rose approximately 11 matm. The surprisingly rapid decline in air-sea partial pressure difference (DpCO2) is primarily a response to an elevated water column inventory of dissolved inorganic carbon (DIC), which, in turn, reflects mostly anthropogenic CO2 input rather than natural interannual variability. The resulting decline in the buffering capacity of the inorganic carbonate system (increasing Revelle factor) sets up a theoretically predicted feedback loop whereby the invasion of anthropogenic CO2 reduces the ocean’s ability to uptake additional CO2. Model simulations for the North Atlantic Ocean and thermodynamic principles reveal that this feedback should be stronger, at present, in colder midlatitude and subpolar waters because of the lower present-day buffer capacity and elevated DIC levels driven either by northward advected surface water and/or excess local air-sea CO2 uptake. This buffer capacity feedback mechanism helps to explain at least part of the observed trend of decreasing air-sea DpCO2 over time as reported in several other recent North Atlantic studies. [less ▲]

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See detailRapid decreases in preoptic aromatase activity and brain monoamine concentrations after engaging in male sexual behavior
Cornil, Charlotte ULg; Dalla, C.; Papadopoulou-Daifoti, Z. et al

in Endocrinology (2005), 146(9), 3809-3820

In Japanese quail, as in rats, the expression of male sexual behavior over relatively long time periods (days to weeks) is dependent on the local production of estradiol in the preoptic area via the ... [more ▼]

In Japanese quail, as in rats, the expression of male sexual behavior over relatively long time periods (days to weeks) is dependent on the local production of estradiol in the preoptic area via the aromatization of testosterone. On a short-term basis (minutes to hours), central actions of dopamine as well as locally produced estrogens modulate behavioral expression. In rats, a view of and sexual interaction with a female increase dopamine release in the preoptic area. In quail, in vitro brain aromatase activity (AA) is rapidly modulated by calcium-dependent phosphorylations that are likely to occur in vivo as a result of changes in neurotransmitter activity. Furthermore, an acute estradiol injection rapidly stimulates copulation in quail, whereas a single injection of the aromatase inhibitor vorozole rapidly inhibits this behavior. We hypothesized that brain aromatase and dopaminergic activities are regulated in quail in association with the expression of male sexual behavior. Visual access as well as sexual interactions with a female produced a significant decrease in brain AA, which was maximal after 5 min. This expression of sexual behavior also resulted in a significant decrease in dopaminergic as well as serotonergic activity after 1 min, which returned to basal levels after 5 min. These results demonstrate for the first time that AA is rapidly modulated in vivo in parallel with changes in dopamine activity. Sexual interactions with the female decreased aromatase and dopamine activities. These data challenge established views about the causal relationships among dopamine, estrogen action, and male sexual behavior. [less ▲]

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See detailRapid detection of Bovine Leukemia Virus infection in a large cattle population with an ELISA performed on pooled sera grouped by herd.
Mammerickx, Marc; Portetelle, Daniel ULg; Nys, J. et al

in Zentralblatt für Veterinarmedizin. Reihe B = Journal of Veterinary Medicine. Series B (1985), 32

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See detailRapid diabetes onset and its reversal among patients treated with second generation antipsychotics
De Hert, M.; Van Eyck, D.; Hanssens, L. et al

in European Neuropsychopharmacology (2005, October), 15(Suppl. 3), 483-484

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