References of "Legros, Jean-Jacques"
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See detailIncidence des perturbations psychoendocriniennes au centre interdisciplinaire de l’andropause (CIA) du CHU de Liège : bilan des 7 premiers mois d’activité
Allouch, A; Bruwier, M; Comte-Tassin, M et al

in Annales d'Endocrinologie (2001), 62(4), 178

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See detailLes thyroïdites auto-immunes
Geenen, Vincent ULg; Warzee, Emmanuelle ULg; Legros, Jean-Jacques ULg

in Revue Médicale de Liège (2001), 56

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See detailEst-il raisonnable de prescrire de l'hormone de croissance aux personnes âgées ?
Legros, Jean-Jacques ULg; Geenen, Vincent ULg; Delmotte, Philippe

in Revue Médicale de Liège (2001), 56

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See detailImplication de la neurohypophyse dans le stress psychique
Scantamburlo, Gabrielle ULg; Ansseau, Marc ULg; Legros, Jean-Jacques ULg

in Encéphale (L') (2001), 27(3, May-Jun), 245-59

Effects of different psychological stimuli on oxytocin (OT) and vasopressin (AVP) secretion are reviewed in animals and in humans. The secretion of neuropituitary hormones is also discussed in various ... [more ▼]

Effects of different psychological stimuli on oxytocin (OT) and vasopressin (AVP) secretion are reviewed in animals and in humans. The secretion of neuropituitary hormones is also discussed in various psychiatric diseases such an anorexia nervosa, bipolar disorder, schizophrenia and obsessive-compulsive disorder. AVP and OT are secreted into the hypophyseal portal circulation by neurons which project from the paraventricular nucleus to the external zone of the median eminence. AVP and OT-containing neurons in the suprachiasmatic and paraventricular nuclei project to limbic areas, including the hippocampus, the subiculum, the ventral nucleus of the amygdala and the nucleus of the diagonal band. Specific AVP receptors which are pharmacologically different from the pressor and antidiuretic AVP receptors have been found in the anterior pituitary. OT receptors have been identified in a variety of forebrain sites. The neurohypophyseal secretion is regulated by the cholinergic muscarinic, histaminergic and beta-adrenergic systems. Stress alters the secretion of one or more of the hypothalamic factors which interact at the pituitary to increase the secretion of ACTH. AVP and OT have been shown to modulate the effect of Corticotropin-Releasing Factor (CRF) on ACTH secretion and appear to play a key role in mediating the ACTH response to stress. Although AVP is a relatively weak secretagogue for ACTH, it markedly potentiates the activity of CRF both in vitro and in vivo. The role of OT is more complex. In vitro, OT stimulates ACTH release at high doses whereas in human it inhibits ACTH secretion at low doses. The type of stressor appear to determine the relative importance of these secretatogues in ACTH response. Several recent studies indicate that psychological stressors display a similar degree of variety of secretagogue release patterns as was found earlier for physical stressors. A bewildering array of technique produces a bewildering array of conclusions. In rats, OT may be an important secretagogue during a novel stimulus, whereas the role for AVP is less clear. Indeed two studies out of ten suggest a stimulating role for AVP. In response to frustration and submission, OT and AVP are secreted. Regarding social isolation, results are difficult to interpret and the role of AVP could be species-dependent. In contrast plasma OT levels do not change. After restraint, ACTH release is primarily mediated by the active increase of OT and AVP does not appear to play a role. When restraint is associated with moderate levels of physical components and during immobilisation, all two secretagogs are involved in the ACTH response. With fear, ACTH response appears to be driven by OT. In humans, one study indicates that high emotionality women increase plasma OT in response to uncontrollable noise. Various neuroendocrine dysregulations have been observed in psychiatric disease. Either an increase or a decrease of the hypothalamic-pituitary-adrenal (HPA) function have been described in several illnesses. Effects of OT appear to be reciprocal to the effects of AVP. OT has been called the "amnestic" neuropeptide due to its capacity to attenuate memory consolidation and retrieval. AVP exhibits a central activating action on mood, memory and selective attention. Underweight patients with anorexia nervosa have abnormally high levels of centrally directed AVP and reduced OT levels. These modifications could enhance the retention of cognitive distortions of aversive consequences of eating. Patients with bipolar disorder show a biphasic secretion of AVP. Depressive episodes are associated with decreased vasopressinergic activity whereas manic episodes involve an increased release. AVP might be responsible for an increased catecholamine activity. In addition, lithium could act as an antagonist to AVP. In schizophrenic patients, studies using the apomorphine stimulation suggest increased oxytoninergic and decreased vasopressinergic functions. These findings are consistent with the beneficial role of AVP on schizophrenic symptoms noted in several trials. The increased OT could be responsible for "positive" symptomatology such as delusions and hallucinations. Obsessive compulsive disorder (OCD) includes a range of cognitive and behavioral disturbances that could be influenced by OT. In animals, several studies have emphasized the role of AVP in promoting repetitive grooming behaviors and maintaining conditioned response to aversive stimuli. In OCD patients, one study have reported that AVP/OT ratio was negatively correlated with symptom severity. However, an independent report found similar AVP concentrations in OC patients without a personal or family history of tic disorder and in normal subjects. Whether these modifications are only a consequence of the central disturbances or whether those peptides could participate in the pathogenesis of these affections remains to be elucidated. [less ▲]

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See detailMétamorphose d'une acromégalie en un adénome hypophysaire non-fonctionnel : Etudes clinique et génétiques
Valdes Socin, Hernan Gonzalo ULg; Stevenaert, Achille ULg; Legros, Jean-Jacques ULg et al

in Annales d'Endocrinologie : XIXe Congrès de la Société Française d'Endocrinologie - Abstract book (2001)

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See detailMetamorphosis of acromegaly to a non-functioning pituitary adenoma
Valdes Socin, Hernan Gonzalo ULg; Stevenaert, Achille ULg; Legros, Jean-Jacques ULg et al

in 5th European Congress of Endocrinology - Abstract book (2001)

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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 detailMelatonine. I. Physiologie de la secretion
Bruls, E.; Crasson, Marion ULg; Legros, Jean-Jacques ULg

in Revue Médicale de Liège (2000), 55(8), 785-92

Melatonin is a hormone mainly secreted by the pineal gland during the dark phase of the light-dark cycle. The best 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 best 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. Although melatonin circadian rhythm is endogenous, based on 25 hour cycles, it is modulated by light-dark cycle. During the day, the light signal is sent to the pineal gland through a special neuronal pathway and inhibits melatonin secretion. During the night, the last neuron of this pathway which is coming from the cervical ganglion superior releases nonadrenalin in the interstitium. Nonadrenalin stimulates melatonin synthesis through cAMP accumulation. Some factors other than light can also influence melatonin levels. Electromagnetic fields, age, male sex, Cushing syndrome, hypogonadotrophic hypogonadism, alcoholism seem to be associated with lower melatonin secretion. Female sex, hypergonadotrophic hypogonadism, sport and fasting seem to be linked to higher melatonin secretion. Some pathologies and drugs can modulate some steps of the neuroanatomic pathway of melatonin synthesis. Stress has no effect. The influence of weight and height is still investigated. Once released, melatonin can act on different organs through specific receptors (retina, supra-chiasmatic nucleus, hypophysis, brain, blood vessels, digestive tract, ovaries). [less ▲]

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See detailExperimental gerontology in Belgium: from model organisms to age-related pathologies
Toussaint, Olivier; Baret, P. V.; Brion, J.-P. et al

in Experimental Gerontology (2000), 35(8), 901-916

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See detailEffect of nicotine on rat gingival fibroblasts in vitro
Lahmouzi, Jamila ULg; Simain-Sato, Franklin ULg; Defresne, Marie-Paule ULg et al

in Connective Tissue Research (2000), 41(1), 69-80

Nicotine from 3 to 5 mM affects growth and survival rate of rat gingival fibroblasts in vitro. Ultrastructural analysis revealed dilated mitochondria and vacuolization in treated cells, suggestive of ... [more ▼]

Nicotine from 3 to 5 mM affects growth and survival rate of rat gingival fibroblasts in vitro. Ultrastructural analysis revealed dilated mitochondria and vacuolization in treated cells, suggestive of necrosis, but increased apoptosis was also revealed by cytometry. On the basis of this in vitro study, it appear that tobacco, through its component nicotine, may directly affect various functions of rat gingival fibroblasts [less ▲]

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See detailOxytocin receptor of small cell carcinoma of human lung cell lines
Pequeux, Christel ULg; Breton, Christophe; Hagelstein, Marie-Thérèse ULg et al

in Pflügers Archiv : European Journal of Physiology (2000), 440/6

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See detail50 Hz Magnetic Field Exposure Influence on Human Performance and Psychophysiological Parameters: Two Double-Blind Experimental Studies
Crasson, Marion ULg; Legros, Jean-Jacques ULg; Legros, Willy ULg et al

in Bioelectromagnetics (1999), 20(8), 474-86

Two double-blind studies were performed to examine magnetic field (MF) exposure effects and to determine the impact of temporal variation (continuous vs. intermittent exposure) of 100 mu T(rms) 50 Hz MF ... [more ▼]

Two double-blind studies were performed to examine magnetic field (MF) exposure effects and to determine the impact of temporal variation (continuous vs. intermittent exposure) of 100 mu T(rms) 50 Hz MF diurnal exposure on psychological and psychophysiological parameters in healthy humans. Three cephalic exposure sessions of 30-min, i.e., sham, continuous, and intermittent (15 s ON/OFF cycles) MF conditions, were involved. Each subject participated in all sessions, which were spaced at 1-wk intervals. In each session, mood ratings and performance measures were obtained before, during, or after exposure and several electrophysiological data (event-related brain potentials [ERP]) were recorded after each exposure session. These criteria were chosen to evaluate sensory functions as well as automatic and voluntary attentional processes. In experiment 1, 21 healthy male volunteers (20 to 27 years of age) were studied. Ten subjects were exposed at 13:30 h, and 11 subjects were exposed at 16:30 h. Statistically significant changes in the amplitude of ERP were observed after MF exposure in the dichotic listening task, indexing selective attention processes. Eighteen of the 21 original male volunteers took part in experiment 2, undertaken to better understand the results related to information processing involved in selective attention and control for ultradian rhythmicity. Exposure time for all the subjects was at 13:30 h. The analysis of the data again revealed significant amplitude changes of the ERP recorded in the dichotic listening task. Moreover, they demonstrated ERP latency and reaction time slowing in the oddball paradigm, a visual discrimination task after real MF exposure. These results also indicate that a low level 50 Hz MF may have a slight influence on event-related potentials and reaction time under specific circumstances of sustained attention. [less ▲]

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See detailCulture of Gingival Fibroblasts on Bioabsorbable Regenerative Materials in Vitro
Simain-Sato, Franklin ULg; Lahmouzi, Jamila ULg; Kalykakis, G. K. et al

in Journal of Periodontology (1999), 70(10), 1234-9

BACKGROUND: The use of membranes in guided tissue regeneration (GTR) can limit the apical migration of gingival cells and favor the establishment of new attachment by periodontal ligament fibroblasts ... [more ▼]

BACKGROUND: The use of membranes in guided tissue regeneration (GTR) can limit the apical migration of gingival cells and favor the establishment of new attachment by periodontal ligament fibroblasts. However, gingival recession during healing following GTR has been described as a frequent complication. The purpose of this study was to determine if gingival fibroblasts are affected by the composition of the bioabsorbable membranes used in mucogingival surgery. METHODS: Two type of bioabsorbable regenerative materials were used as cell carriers. Wistar rat gingival fibroblasts (RGF) were obtained from attached gingiva, cut into small fragments, and placed in culture dishes. When confluent, cells were detached using trypsin and identified as "first transferred cells" (P1). At the third passage (P3), cell count, trypan blue exclusion test, acid phosphatase activity, DNA synthesis, phase contrast microscopy, and scanning electron microscopy were performed. The cells were then placed in wells containing the membranes and incubated for 72 hours. RESULTS: When examined under microscopy, the control wells (without membranes) showed one cell type with the elongated appearance characteristic of fibroblasts. The wells with membranes showed an altered cell morphology with a high proportion of cell fragments regardless of the type of membrane used. CONCLUSIONS: These results suggest that cell carrier membranes could affect RGF morphology and thus alter gingival tissue healing following GTR. [less ▲]

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See detailLe syndrome de tension prémenstruelle ou dysphorie prémenstruelle
Legros, S.; Foidart, Jean-Michel ULg; Gaspard, Ulysse ULg et al

in Revue Médicale de Liège (1999), 54(4), 268-73

Premenstrual Tension Syndrome (PMS) has always existed: it has been first described by an endocrinologist from New York in 1931. It is responsible for significant and psychological disorders which justify ... [more ▼]

Premenstrual Tension Syndrome (PMS) has always existed: it has been first described by an endocrinologist from New York in 1931. It is responsible for significant and psychological disorders which justify the study of its pathogenesis. Hormonal dysfunction has been demonstrated among women who are at risk for PMS; nevertheless, it has been shown that neurological transducers are also affected, such as GABAergic, serotoninergic and endorphinic systems. Interactions between the two systems allow to raise the hypothesis of an inbalance between GABAergic and progesterone derived neurosteroids in a psychoneuroendocrinological model. Based on this hypothesis, psychological symptoms can be efficiently treated by anxiolytic or antidepressant treatment. On the other hand, progesterone derivatives and, sometimes, diuretics, are useful on physical symptoms. As far as we know there is so far no single treatment of demonstrated efficacy in the PMS. [less ▲]

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See detailCharacterization of menin from leucocytes of normal and men-1 affected individuals
Poncin, Jacques ULg; Closset, Jean ULg; Legros, Jean-Jacques ULg et al

in 81st Annual Meeting of the Endocrine society - Abstract book (1999)

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See detailDe nouveaux acteurs dans la physiopathologie du metabolisme de l'eau: les aquaporines
Pequeux, Christel ULg; Brilot, Fabienne; Martens, Henri ULg et al

in Revue Médicale de Liège (1999), 54(11), 867-74

Aquaporins are transmembrane proteins mediating water transport across plasma membrane of animal, vegetal or bacterial cells. Among the ten aquaporins known in mammals, six are located in kidney and take ... [more ▼]

Aquaporins are transmembrane proteins mediating water transport across plasma membrane of animal, vegetal or bacterial cells. Among the ten aquaporins known in mammals, six are located in kidney and take part in urine concentration. AQP2 is vasopressin regulated, it is the only family member to be implicated in human pathology, such as nephrogenic diabetes insipidus, congestive heart failure, hepatic cirrhosis, nephrotic syndrome or SIADH. Aquaporins are expressed in a wide variety of tissues, such as brain or gastrointestinal tractus, and suggest a role in water tissue exchange, but their real function is still not define. To know the physiological impact of aquaporins, AQP1, AQP3, AQP4 and AQP5 knockout mice have been created and their phenotype analysed. [less ▲]

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See detailGraft of autologous fibroblasts in gingival tissue in vivo after culture in vitro. Preliminary study on rats.
Simain-Sato, Franklin ULg; Lahmouzi, Jamila ULg; Heinen, Ernst ULg et al

in Journal of Periodontal Research (1999), 34(6), 323-8

Several grafting techniques and guided tissue regeneration techniques (GTR) have been well-developed in periodontal surgery. However, these techniques could induce pain and side effects, such as a ... [more ▼]

Several grafting techniques and guided tissue regeneration techniques (GTR) have been well-developed in periodontal surgery. However, these techniques could induce pain and side effects, such as a gingival recession during the healing period following the therapy. The graft of a small autologous connective tissue, using non-invasive surgical techniques could yield several benefits for the patients. Our preliminary study explores the feasibility of collecting healthy gingival tissues, culturing them in vitro to amplify rat gingival fibroblasts (RGF) and inoculating the obtained cells into autologous rat gingival tissues in vivo. Gingival tissues samples were cultured as explants as described by Freshney et al. and Adolphe. Confluent cells surrounding explants were detached after 7 d of culture from Petri dishes using 0.05% trypsin and designated "first transferred cells" (T1). At the third passage (T3), cells cultured as monolayer were either examined under microscopy--phase contrast, scanning, or transmission electron--or numerated after trypan blue exclusion test. Autologous RGF labelled with fluorochrome were inoculated at the vestibular and palatine site of gingival tissue close to the superior incisors. In this preliminary study, 12 Wistar rats were used; for each, 2 biopsies were dissected and fixed for phase contrast or fluorescence microscopy. On d 1, 3 and 7 after injection in rat gingival tissues, fluorochrome-labelled cells could be detected in all these. [less ▲]

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See detailLa vasopressine, mais pas l'ocytocinen ni le CRF, est impliquée dans la réponse du cortisol aux stress pschologiques, chez des humains sains mais anxieux
Boudare, M; Pequeux, Christel ULg; Hagelstein, Marie-Thérèse ULg et al

in Annales d'Endocrinologie (1999), 60(4), 360

Le but général de cette étude est d'évaluer la réponse au stress, à la fois sous un angle psychologique et biologique, afin d'établir l'éventuel lien qui pourrait être observé entre ces deux paramètres.

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