Biphasic locomotor effects of the dopamine D-sub-1 agonist SKF 38393 and their attenuation in non-habituated mice

in Psychopharmacology (1993), 110(1-2), 69-75

Examined the locomotor stimulatory effects of the dopamine D-sub-1 receptor partial agonist SKF 38393 in male C57B1/6J mice. Non-habituated mice showed marked dose-related (3-300 mg/kg, subcutaneously ... [more ▼]

Examined the locomotor stimulatory effects of the dopamine D-sub-1 receptor partial agonist SKF 38393 in male C57B1/6J mice. Non-habituated mice showed marked dose-related (3-300 mg/kg, subcutaneously) locomotor stimulation. The time-course effect was biphasic at very high doses (100-300 mg/kg), with dose-related locomotor depression followed by dose-related long-term hyperlocomotion. For all doses, locomotor effects were detectable throughout the 4-hr test period. To determine whether these effects were mediated by D-sub-1 receptor stimulation, effects of SKF 38393 were assessed in combination with behaviorally inactive and active doses (0.1 and 0.2 mg/kg, respectively) of the selective D-sub-1 receptor antagonist SCH 39166. Both doses of SCH 39166 attenuated the hyperlocomotion induced by 30 mg/kg of the agonist to a similar degree. However, neither dose was able to reverse either the depressant or the stimulatory effects of 300 mg/kg SKF 38393. ((c) 1997 APA/PsycINFO, all rights reserved) [less ▲]

La bipolarité en pédopsychiatrie : proposition d'une nouvelle sémiologie

Poster (2006, January)

La bipolarité en pédopsychiatrie : proposition d'une nouvelle sémiologie. Le diagnostic de bipolarité reste peu connu des pédopsychiatres. Il faut en moyenne 10 ans et 3 à 5 médecins avant qu'un ... [more ▼]

La bipolarité en pédopsychiatrie : proposition d'une nouvelle sémiologie. Le diagnostic de bipolarité reste peu connu des pédopsychiatres. Il faut en moyenne 10 ans et 3 à 5 médecins avant qu'un diagnostic correct ne soit posé. Notre expérience, se rapportant à plus d'une centaine d'enfants de 20 mois à 8 ans, met en évidence une sémiologie nuancée qui permet un diagnostic rapide et précoce de la bipolarité. Nous relevons un "tempérament maniaque bipolaire simple" avec sept axes sémiologiques : 1. la clinique du sommeil, 2. une forme "super-énergétique", 3. un "mal-être en situation d'être seul", 4. des couleurs affectives expressives, 5. les désinhibitions, 6. la prépondérance de l'attention divergente sur l'attention convergente, 7. la tendance à l'hyperactivité. Nous évoquons pour ces sept axes l'expression clinique par tranche d'âge jusqu'à la vie adulte. La mise en évidence d'une clinique du "mal-être en situation d'être seul" est l'élément le plus original de notre recherche ; ce mal-être est à distinguer de l'angoisse de séparation, même s'il peut y avoir un continuum ; il n'est pas pathognomonique de la bipolarité mais semble en faire systématiquement partie ; nous formulons l'hypothèse qu'il serait lié à un manque d'efficience "d'une jauge interne d'évaluation du temps". Nous donnons le diagnostic différentiel entre le "tempérament maniaque bipolaire simple" et l'ADHD. Ensuite, nous proposons une caractérisation en 4 formes sémiologiques des états bipolaires dans l'enfance. Nous complétons cette sémiologie de base par différentes comorbidités possibles qui vont apporter d'autres accentuations cliniques. Nous mentionnons le diagnostic différentiel avec les troubles schizo-affectifs. Selon le temps imparti nous pouvons également évoquer : des métaphores explicatives et thérapeutiques que nous donnons au lieu de parler de diagnostic ; des réflexions neurophysiologiques jointes à cette sémiologie ; les médications spécifiques et leur efficacité dans la petite enfance ; le pronostic qui peut radicalement changer avec une prise en charge précoce. [less ▲]

Bipolarité et ADHD, une sémiologie développementale dimensionnelle pour les reconnaître et les différencier dès la petite enfance

Conference given outside the academic context (2010)

L'exposé présente les résultats d'une recherche sémiologique qualitative qui a pour finalité de mieux préciser la sémiologie de la bipolarité dès la petite enfance et de réaliser un diagnostic ... [more ▼]

L'exposé présente les résultats d'une recherche sémiologique qualitative qui a pour finalité de mieux préciser la sémiologie de la bipolarité dès la petite enfance et de réaliser un diagnostic différentiel précis avec les troubles de l'attention avec ou sans hyperactivité. Cette recherche approche la clinique à partir d'une sémiologie dimensionnelle et développementale. [less ▲]

Bipolarity in Alexis de Tocqueville’s, Karl Marx’s, Friedrich Nietzsche’s, and Michael Oakeshott’s Political Theories

in Cahiers de Sciences Politiques de l'ULg (2009), (15),

In Democracy in America, Alexis de Tocqueville argues that passions for both equality and liberty constitute the chief attributes of liberal democracy. In the same century, Karl Marx and Friedrich Engels ... [more ▼]

In Democracy in America, Alexis de Tocqueville argues that passions for both equality and liberty constitute the chief attributes of liberal democracy. In the same century, Karl Marx and Friedrich Engels –followed by Lenin in the 20th century– contend that history is chiefly characterized by the conflict between those who own the means of productions and those who don’t –those who produce. In Beyond Good and Evil (BGE) and in On the Genealogy of Morals (OGM), Friedrich Nietzsche describes the whole of history as a permanent bipolarity between the strong –committed to the master morality of good vs. bad– and the weak –committed to the slave morality of good vs. evil. Michael Oakeshott, in The Politics of Faith and The Politics of Scepticism, suggests that, since the fifteenth century, modern politics can be characterized by two –logically opposite and yet practically complementary– styles of politics: the politics of faith and the politics of scepticism. Although they disagree on the characterization of the poles themselves, all four philosophers describe politics as a bipolarity: a dynamic between two poles. In this paper, I shall attempt to describe –and then reflect on– the dynamics of bipolarity in these four major works of political theory. Six sets of questions inform the essay. First, was there ever a time in which the political poles identified by the author were either nonexistent or different from the currently predominant or ultimate ones? If so, then why and what were the characteristics of that time? Second, what characterizes the political poles? Are the apparent poles more complicated than what meets the eye upon a first reading? Does the author reveal dimensions, levels, or different incarnations of the poles, or in fact more than two poles? Third, are the characteristics of the poles altered in any way by either political actors, or by way of their confrontation or interaction with one another? If so, how? If not, then why not? Fourth, does the identified bipolarity spontaneously create a political equilibrium or evolve into another, or is intervention required to produce an equilibrium or evolution? Fifth, if the latter, does the author recommend such intervention? Does the author give a normative teaching or assess the identified poles? Sixth, is the bipolarity theory valid? Does it accurately describe politics? The paper opens with the discussion of the first two sets of questions –i.e. the characterization of politics by Tocqueville, Marx, Nietzsche, and Oakeshott. The second section focuses on the intricate dynamics between the poles and on the mediation occurring between them –i.e. the third and fourth sets of questions. The fifth sets of question –i.e. whether the author gives a descriptive or a normative teaching– informs the third section of the paper. In the conclusion, I attempt to offer a personal view to the final question –i.e. the validity of the bipolarity theory offered by the four philosophers– and try to answer it in the Belgian federal context. [less ▲]

Bird Assemblages In A Mixed Woodland-Farmland Landscape: The Conservation Value Of Silviculture-Dependant Open Areas In Plantation Forest

in Forest Ecology & Management (2006), 227(1-2),

Although considered by some as a less "ecologically suitable" forestry model than "near-natural" stand management, even-aged plantation forest management, with regeneration procedure invo lving ... [more ▼]

Although considered by some as a less "ecologically suitable" forestry model than "near-natural" stand management, even-aged plantation forest management, with regeneration procedure invo lving clearcutting, creates temporary habitat for many early-successional birds. The present study addresses the question of the conservation value for birds of clearcutting-related open areas in European temperate forest, in the context of a mixed woodland-farmland landscape. The point count technique was used to census the breeding birds on 300 sampling p lots, distributed in the 8 main habitat types of the Ardenne region (Southern Belgium), including agricultural land, edge habitats, closed forest habitats and open areas in forest. Most of these open areas in forest derive from clearcutting practices, rapidly planted with young Norway Spruce (Picea abies). We quantified the conservation value of a given habitat type by using a "conservation value index", integrating the frequency of occurrence of each species in the considered habitat and their conservation status in Europe or in Southern Belgium. Both conservation value index and species richness were higher for edge habitats and open areas in forest, compared to forest interior and agricultural land. Detrended Correspondence Analysis of the plot species lists showed that bird assemblages from open area in forest are not intermediate between forest and agricultural open land, as opposed to external edge habitats. Hence, open areas in forest do not contain bird assemblages composed of forest species mixed with colonizing agricultural species but rather shelter specific bird assemblages. An Indicator Species analysis further emphasized this specificity and identified 7 species, which, in the Ardenne context, form a group of species specific to open areas in forest. Due to major changes of land use in the Ardenne during the 20th century, which leads to a tremendous decrease of moor, heath and fallow land areas, clearcut openings in the plantation forest progressively gained high conservation value at the regional scale. Further studies about habitat requirement of the conservation-interest species inhabiting these open areas is needed, including a better understanding of how early-successional species react to forest planning. If plantation forestry evolves to an uneven-aged and more permanently closed forest, then other options, including semi-natural habitat restoration, are urgently required to save early-successional bird communities. [less ▲]

Birefringent achromatic phase shifters for nulling interferometry and phase coronagraphy

in Earths: DARWIN/TPF and the Search for Extrasolar Terrestrial Planets (2003, October 01)

Achromatic Phase Shifters are mandatory components in the field of nulling interferometry and phase coronagraphy. Indeed, in order to detect faint objects (e.g. exo-planets) around a central bright star ... [more ▼]

Achromatic Phase Shifters are mandatory components in the field of nulling interferometry and phase coronagraphy. Indeed, in order to detect faint objects (e.g. exo-planets) around a central bright star, one must attenuate the latter by all means. To do this, the most efficient way is to "create" a destructive interference on the blinding light. This technique is called nulling and is common to the two fields mentioned above; the first with several telescopes, the second with only a single aperture. How does it work? The incoming light from the central object is divided into several beams on which one applies a differential Ï phase shift by means of these so-called phase shifters. Then, when the beams are properly recombined together, they simply subtract from each other. "Achromatic" means that we can apply this process over a large spectral bandwidth. This quality will not only be required for the detection and characterization of exo-planets but also for several other astrophysical objects involving huge contrasts like dust shells around young bright stars, AGN,... The proposed birefringent phase shifters and the original implementation schemes we suggest should provide flexible and powerful solutions for these purposes. [less ▲]

The birth of the Belgian Network for Science, Technology and Society (BSTS Network)

in EASST Review (2012), 31(1), 9-12

Bis repetita non placent

Article for general public (1996)

Bis-tetrahydroisoquinoline derivatives: AG525E1, a new step in the search for non-quaternary non-peptidic small conductance Ca2+-activated K+ channel blockers

in Bioorganic & Medicinal Chemistry Letters (2008), 18(11), 3440-3445

So far, small conductance Ca2+-activated K+ channel (SK) blockers mostly consist of quaternary ammonium derivatives or peptides. Due to their physicochemical properties, these blockers are not suitable to ... [more ▼]

So far, small conductance Ca2+-activated K+ channel (SK) blockers mostly consist of quaternary ammonium derivatives or peptides. Due to their physicochemical properties, these blockers are not suitable to study the physiological roles of SK channels in the central nervous system in vivo. Herein, we report the discovery of a chiral bis-tertiary amine with SK blocking properties from chemical modulation of laudanosine. AG525E1 has an affinity for SK channels (K-i = 293 nM) approximately 100-fold higher than the tertiary compound laudanosine (K-i similar to 30 mu M) and similar to the charged compound dequalinium (K-i = 221 nM). AG525E1 equipotently blocks SK1, SK2 and SK3 currents in transfected cell lines. Because of its basic and lipophilic properties, it can reach central SK targets. (c) 2008 Elsevier Ltd. All rights reserved. [less ▲]

Bisindole alkaloids from Strychnos guianensis are effective antagonists of nicotinic acetylcholine receptors in cultured human TE671 cells

in Naunyn-Schmiedeberg's Archives of Pharmacology (2003), 367(3), 253-259

Several mono- and bisindole quaternary alkaloids isolated from the stem bark of Strychnos guianensis have recently been shown to be effective blockers of neuromuscular transmission in mice. In this study ... [more ▼]

Several mono- and bisindole quaternary alkaloids isolated from the stem bark of Strychnos guianensis have recently been shown to be effective blockers of neuromuscular transmission in mice. In this study, we used a human clonal cell line (TE671) expressing muscle-type nicotinic acetylcholine receptors. The agonist carbamylcholine activated a receptor-mediated Rb-86(+) efflux and this activation was antagonized by the indole alkaloids, the most active being bisindole bisquaternary compounds. The most effective antagonist, guiachrysine, had an IC50 around 0.43 muM in the presence of 0.5 mM carbamylcholine, compared to 0.16 muM for d-tubocurarine, the most potent curarizing alkaloid. Guiaflavine and 5',6'-dehydroguiaflavine were slightly less effective. Monoindole compounds were 10 to 100 times less potent than bisindole alkaloids. Kinetic analysis showed that the inhibition of the carbamylcholine-dependent Rb-86(+) efflux by guiaflavine was of mixed competitive and uncompetitive type. The competitive component (K-I = 0.21 muM) is presumably due to binding at the acetylcholine site, while the uncompetitive component (K'(I) = 0.92 muM) may be due to open channel block. [less ▲]