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See detailHormonal regulation of brain circuits mediating male sexual behavior in birds
Ball, G. F.; Balthazart, Jacques ULg

in Physiology & Behavior (2004), 83(2), 329-346

Male sexual behavior in both field and laboratory settings has been studied in birds since the 19th century. Birds are valuable for the investigation of the neuroendocrine mechanisms of sexual behavior ... [more ▼]

Male sexual behavior in both field and laboratory settings has been studied in birds since the 19th century. Birds are valuable for the investigation of the neuroendocrine mechanisms of sexual behavior, because their behavior can be studied in the context of a large amount of field data, well-defined neural circuits related to reproductive behavior have been described, and the avian neuroendocrine system exhibits many examples of marked plasticity. As is the case in other taxa, male sexual behavior in birds can be usefully divided into an appetitive phase consisting of variable behaviors (typically searching and courtship) that allow an individual to converge on a functional outcome, copulation (consummatory phase). Based primarily on experimental studies in ring doves and Japanese quail, it has been shown that testosterone of gonadal origin plays an important role in the activation of both of these aspects of male sexual behavior. Furthermore, the conversion of androgens, such as testosterone, in the brain to estrogens, such as 17beta-estradiol, is essential for the full expression of male-typical behaviors. The localization of sex steroid receptors and the enzyme aromatase in the brain, along with lesion, hormone implant and immediate early gene expression studies, has identified many neural sites related to the control of male behavior. The preoptic area (POA) is a key site for the integration of sensory inputs and the initiation of motor outputs. Furthermore, prominent connections between the POA and the periaqueductal gray (PAG) form a node that is regulated by steroid hormones, receive sensory inputs and send efferent projections to the brainstem and spinal cord that activate male sexual behaviors. The sensory inputs regulating avian male sexual responses, in contrast to most mammalian species, are primarily visual and auditory, so a future challenge will be to identify how these senses impinge on the POA-PAG circuit. Similarly, most avian species do not have an intromittent organ, so the projections from the POA-PAG to the brainstem and spinal cord that control sexual reflexes will be of particular interest to contrast with the well characterized rodent system. With this knowledge, general principles about the organization of male sexual circuits can be elucidated, and comparative studies relating known species variation in avian male sexual behaviors to variation in neural systems can be pursued. (C) 2004 Elsevier Inc. All rights reserved. [less ▲]

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See detailHormonal regulation of growth hormone mRNA
Wegnez, M.; Schachter, B. S.; Baxter, J. D. et al

in DNA (1982), 1(2), 145-53

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See detailHormonal requirements for basement membrane collagen deposition by cultured rat mammary epithelium.
Liotta, L. A.; Wicha, M. S.; Foidart, Jean-Michel ULg et al

in Laboratory Investigation : Journal of Technical Methods & Pathology (1979), 41(6), 511-8

Alveoli and ducts isolated from virgin rat mammary glands synthesize basement membrane collagen (typeIV) in primary culture. Using purified antibodies to type IV collagen, prominent intracellular and ... [more ▼]

Alveoli and ducts isolated from virgin rat mammary glands synthesize basement membrane collagen (typeIV) in primary culture. Using purified antibodies to type IV collagen, prominent intracellular and extracellular fluorescence is observed in the epithelium. No fluorescence is observed with antibodies to collagen type I and III. From quantitation of the incorporation of [14c]proline-labeled proteins, 1.5 to 2.5 per cent of the newly synthesized proteins are collagen. Type IV collagen from these cultures was biochemically identified on the basis of (1) the high ratio of labeled 3-hydroxyproline to 4-hydroxyproline (1:10), (2) the gel electrophoretic pattern of the collagenase-sensitive proteins precipitated with 1.7 M NaCl, (3)the failure of the collagen to bind to diethylaminoethyl-cellulose, and(4)the immunologic cross-reactivity with mouse tumor type IV is identical with that of type IV collagen from other sources. When the supportive hormones, insulin, prolactin, hydrocortisone, progesterone, and estradiol are removed from the cultures, there is a 90 per cent reduction in the amount of [3H]proline recovered in collagen synthesis coincides with only a 30 percentdrop in the growht rate and a 20 per cent drop in total protein synthesis of the sells over the 24-hour period without hormones. Pulse-chase experimout hormones. Pulse-chase experiments revealed an enhanced turnover of collagen following hormone withdrawal. This system may be an in vitro model of collagen turnover in mammary gland in involution. [less ▲]

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See detailHormonal status during puberty and criteria of selection in double-muscled Belgian White Blue bull.
Renaville, Robert ULg; Burny, A.; Portetelle, Daniel ULg et al

in Proceedings, 3rd World Congress on Sheep and Beef Cattle Breeding,19-23 June 1988, Paris. Volume 1. (1988)

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See detailHormonal status during puberty and criteria of selection in double-muscled Belgian White Blue bulls
Renaville, Robert ULg; Burny, Arsène; Portetelle, Daniel ULg et al

in 3 World Congress on Sheep and Beef Cattle breeding (1988)

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See detailHormonal, metabolic and structural investigation in a conscious canine model of early heart failure induced by rapid right ventricular pacing
Mc Entee, Kathleen ULg; Clercx, Cécile ULg; Dessy, C. et al

in 10th ESVIM Meeting - Neuchatel - Suisse - Octobre 2000 (2000, October)

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See detailHormone de croissance et Qualité de la vie
Beckers, Albert ULg

Scientific conference (1994, May 07)

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See detailHormone de croissance placentaire humaine : expression par génie génétique et relation structure-activité
Igout, Ahmed ULg; Frankenne, Francis; Scippo, Marie-Louise ULg et al

in Revue Française d'Endocrinologie Clinique, Nutrition, et Métabolisme (La) (1992), 3

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See detailHormone genes : Structure, evolution and expression in bacteria
Goodman, H. M.; Hallewell, R. A.; Martial, Joseph ULg et al

in Molecular Endocrinology (1979)

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See detailL'hormone placentaire somato-mammotrope bovine
Beckers, Jean-François ULg

Post doctoral thesis (1983)

Nos études ont porté en premier lieu sur l’isolement et la purification de l’hormone somato-mammotrope (HPSM) bovine à partir des cotylédons fœtaux de placentas provenant de vaches gestantes de 3 à 6 mois ... [more ▼]

Nos études ont porté en premier lieu sur l’isolement et la purification de l’hormone somato-mammotrope (HPSM) bovine à partir des cotylédons fœtaux de placentas provenant de vaches gestantes de 3 à 6 mois. La préparation d’HPSM purifiée s’est avérée homogène à l’électrophorèse en gel de polyacrylamide. Déterminé par comparaison avec celui de différentes protéines connues, le poids moléculaire de l’HPSM se situe à 33.000 daltons. Son point isolélectrique est de 5,2. Dans les dosages de la prolactine et de l’hormone de croissance par liaison radiocompétitive aux récepteurs membranaires, l’HPSM présente une activité bifonctionnelle, supérieure à celle de s préparations de référence (prolactine PRL-NIH-B4 et hormone de croissance GN-NIH-B18). Marquée à l’iode 125, une partie de l’HPSM conserve intactes ses caractéristiques de liaison. L’HPSM 125 I se lie aux récepteurs hépatiques et mammaires, confirmant l’activité bifonctionnelle de l’hormone. Une liaison spécifique de l’HPSM 125 I est observée chez la vache au niveau de différents tissus tels la glande mammaire, le foie, le corps jaune, l’endomètre et le tissus adipeux. La glande mammaire bovine comporte des sites de liaison différents et spécifiques pour la prolactine et l’hormone de croissance. L’immunisation de lapins au moyen de l’HPSM purifiée a permis l’obtention d’antisérums spécifiques, autorisant la mise au point d’un dosage radioimmunologique sensible. Les cotylédons fœtaux sont trois à quatre fois plus riches en hormone que les cotylédons maternels. Le dosage de l’HPSM dans les liquides amniotiques et allantoïdiens révèle leur faible teneur en hormone. La concentration en HPSM du sérum est élevée chez les fœtus jeunes, elle diminue ensuite régulièrement en fonction de l’âge. L’HPSM apparaît dans le sérum maternel entre le 26ème et le 110ème jour de la gestation. Ensuite, sa concentration s’élève régulièrement jusqu’à la parturition. [less ▲]

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See detailHormone Therapy and Breast Cancer Risk
Foidart, Jean-Michel ULg; Desreux, Joëlle ULg; Pintiaux, Axelle ULg et al

in Climacteric : The Journal of the International Menopause Society (2007), 10(Suppl 2), 54-61

Hormone therapy (HT) is the most efficacious intervention for the relief of climacteric symptoms. Controversies surrounding HT have left many women puzzled and afraid. Gynecologists are faced with long ... [more ▼]

Hormone therapy (HT) is the most efficacious intervention for the relief of climacteric symptoms. Controversies surrounding HT have left many women puzzled and afraid. Gynecologists are faced with long-standing beneficial assumptions challenged by an abundance of robust detrimental new data, with little guidance on how to interpret these findings. Prescriptions for HT (and incidence of breast cancers in some areas) have fallen over the last 3 years due to anxiety provoked about breast cancer risk and recurrence. The current 'clinical climate' is against HT. Due to a lack of effective alternatives, women suffering from estrogen-deficiency symptoms are still requesting objective information about HT, particularly those at higher risk of breast cancer or those with a past history of breast cancer. In this situation, discussion of the current clinical uncertainty surrounding the use of HT must be undertaken to ensure that women are adequately informed. The objective of this presentation is to provide a framework for understanding breast cancer risk associated with HT. What are the precise molecular mechanisms of estrogen and progestin in the initiation of breast cancer? Does the risk of estrogen-only therapy on breast cancer vary by dose, constituent, route and duration of administration and cessation of use? Does HT, in addition to increasing risk for breast cancer, affect the type of breast cancer (lobular and ductal) diagnosed? Is HT associated with breast cancers that have better prognostic factors? How relevant are the changes in mammographic breast density associated with HT for the evaluation of breast cancer risk? What is the additional global health risk/benefit ratio associated with the selective use of progesterone or progestin that may confer a significant cardiovascular benefit, such as drospirenone? It is currently assumed and tested that new hormones with particular pharmacological profiles may ultimately achieve their therapeutic goal of relieving climacteric symptoms without an associated moderate increased risk of breast cancer. [less ▲]

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See detailHormonelle Befunde bei Störungen der Ovarialfunktion des Rindes
Derivaux, Jules; Ectors, Francis ULg; Beckers, Jean-François ULg

in Deutsche Tierärztlich Wochenschrift (1976), 83

The hormonal pattern was studied in 54 animals: 34 heifers with seasonal anoestrus, 13 cows with post-partum anoestrus, 5 cows with nymphomania and 2 cows superovulated. Seasonal and post partum anoestrus ... [more ▼]

The hormonal pattern was studied in 54 animals: 34 heifers with seasonal anoestrus, 13 cows with post-partum anoestrus, 5 cows with nymphomania and 2 cows superovulated. Seasonal and post partum anoestrus are characterized by basal levels of progesterone, FSH and LH, while oestradiol level is more variable and higher in post partum anoestrus due to the proper activity of the ovary. Nymphomania is a hyperfolliculinemic syndrome; cystic puncture leads to a fall in oestradiol and a surge in FSH and LH but of inequal intensity. The level of the latter hormone is often too low to induce luteinization; cystic degeneration of the ovary is associated with LH deficiency. In superovulated cows, hormonal pattern is like in normal cyclic cows but more pronounced. [less ▲]

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See detailHormones and sexual impotence
Legros, Jean-Jacques ULg; Chiodera, P.; Mormont, Christian ULg et al

in De Wied, D.; Van Keer, P.A. (Eds.) Hormones and the brain (1980)

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See detailHormones modulate the concentration of cytoplasmic progestin receptors in the brain of male ring doves (Streptopelia risoria).
Balthazart, Jacques ULg; Blaustein, J. D.; Cheng, M. F. et al

in Journal of Endocrinology (1980), 86(2), 251-61

A cytoplasmic progestin receptor has been characterized in the brain of castrated ring doves using an in-vitro assay that measures the binding of a synthetic progestin, [3H]17 alpha,21-dimethyl-19-nor ... [more ▼]

A cytoplasmic progestin receptor has been characterized in the brain of castrated ring doves using an in-vitro assay that measures the binding of a synthetic progestin, [3H]17 alpha,21-dimethyl-19-nor-pregna-4,9-diene-3,20-dione(promegestone; R5020). The affinity of the receptor was similar in both the hyperstriatum and the hypothalamus (Kd approximately equal to 4 X 10(-10) mol/l). Its concentration was higher in the anterior hypothalamus-preoptic area (63 +/- 4 fmol/mg (S.E.M.) protein) than in other brain regions (posterior hypothalamus, 33 +/- 5; hyperstriatum, 28 +/- 3; midbrain, 17 +/- 4 fmol/mg protein; n = 7). Progesterone and R5020 competed well for binding but oestradiol and 5 beta-dihydrotestosterone did not. Corticosterone and, to a lesser extent, testosterone and 5 alpha-dihydrotestosterone completed for binding but much higher concentrations were required than for progestins. Injections of testosterone (200 micrograms testosterone propionate daily for 7 days) significantly increased the concentration of progestin receptors in the anterior and posterior hypothalamus without having any significant effect on other brain areas. Shorter treatment, lasting for 2 days, with testosterone propionate (200 micrograms daily), 5 alpha-dihydrotestosterone (200 micrograms daily) or oestradiol benzoate (50 micrograms daily) did not always cause this increase but seven injections of oestradiol benzoate (50 micrograms daily for 7 days) were even more effective than seven injections of testosterone propionate (200 micrograms daily for 7 days). These data suggested that the sensitivity to progesterone of the brain of the bird changes as a consequence of increases in the level of testosterone in the circulation. [less ▲]

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See detailHormones, Simulated Microgravity and Hypergravity affect Bone and other Physiological Systems in Zebrafish Larvae
Aceto, Jessica ULg

Doctoral thesis (2015)

Zebrafish (Danio rerio) are increasingly used for physiological, genetic and developmental studies. Understanding the consequences of altered gravity on bone development and on general physiology in an ... [more ▼]

Zebrafish (Danio rerio) are increasingly used for physiological, genetic and developmental studies. Understanding the consequences of altered gravity on bone development and on general physiology in an entire organism remains to date incomplete. We used altered drug treatment and gravity experiments to evaluate their effects specifically on bone formation and more generally on whole genome gene expression. We started treatments at 5 days post-fertilization (dpf) and analyze early modifications in gene expression after 1 day using microarrays and the consequences on bone formation after 5 days using specific staining. We performed chemical treatments (Parathyroid Hormone, Vitamin D3), exposure to three different microgravity simulation devices (Clinostat, Random Positioning Machine and Rotating Wall Vessel) and finally exposure to hypergravity and "relative microgravity" in the Large Diameter Centrifuge. By combining morphometric tools with an objective scoring system for the state of development for each element in the head skeleton, and specific gene expression analysis, we confirmed and characterized in detail the decrease or increase of bone formation caused by a 5 day treatment (from 5dpf to 10dpf) with, respectively parathyroid hormone (PTH) or vitamin D3 (VitD3). Microarray transcriptome analysis after 24 hours treatment reveals a general effect on physiology upon VitD3 treatment, while PTH causes more specifically developmental effects. The microgravity simulators used were the 2D clinostat, random positioning machine and rotating wall vessel. Only clinorotation caused a significant decrease of bone formation when applied between 5 to 10dpf. This effect was not due to stress, as assessed by measuring cortisol levels in treated larvae. The two other devices caused no effect, or a slight acceleration of ossification. Gene expression results after one day in simulated microgravity indicate that musculo-skeletal, cardiavascular, and nuclear receptor systems are affected, however often in opposite directions in clinorotation compared to the two other devices. Based on the effects on bone formation and on the biological functions found to be affected, we conclude that clinorotation is the most appropriate method to simulate microgravity on ground when using free-swimming organisms such as zebrafish larvae. Hypergravity (3g from 5dpf to 9 dpf) exposure results in a significantly larger head and a significant increase in bone formation for a subset of the cranial bones. Gene expression analysis after 24hrs at 3g revealed differential expression of genes involved in the development and function of the skeletal, muscular, nervous, endocrine and cardiovascular systems. Finally, we propose a novel type of experimental approach, the "Reduced Gravity Paradigm", by keeping the developing larvae at 3g hypergravity for the first 5 days before returning them to 1g for one additional day. 5 days exposure to 3g during these early stages also caused increased bone formation, while gene expression analysis revealed a central network of regulatory genes (hes5, sox10, lgals3bp, egr1, edn1, fos, fosb, klf2, gadd45ba and socs3a) whose expression was consistently affected by the transition from hyper- to normal gravity. [less ▲]

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See detailHormonosubstitution postmenopausique et risque de cancer mammaire: une mise a jour
van den Brule, F.; Lifrange, Eric ULg; Pintiaux, Axelle ULg et al

in Revue Médicale de Liège (2003), 58(4), 254-60

Numerous studies have examined the risk of breast cancer in patients with postmenopausal hormone substitution. Most of these studies are retrospective, and a few recent studies are prospective. The ... [more ▼]

Numerous studies have examined the risk of breast cancer in patients with postmenopausal hormone substitution. Most of these studies are retrospective, and a few recent studies are prospective. The observed results present with weak variations from baseline and major heterogeneity. Some studies highlight a slightly increased relative risk of breast cancer. A reanalysis of 51 studies demonstrates a relative risk of 1.35 for developing breast cancer during hormone substitution, with a 2.3% increased risk per year of use. Recently, the results of the WHI study have shown a slight increase of some risks of disease, including breast cancer (relative risk, 1.26). These results have induced the interruption of one of the 3 arms of the study (that of the patients treated with an estrogen-progestin combination), and have provoked a new discussion about the benefits and risks associated with hormone substitution. These facts have been largely related and commented in the general press. In this article, we review the important studies concerning this topic. [less ▲]

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See detailL'hormonothérapie de substitution transdermique: une mode ou un avantage?
Foidart, Jean-Michel ULg; Desreux, Joëlle ULg; Pintiaux, Axelle ULg et al

in Revue Médicale de Liège (1998), 53(4), 208-11

This review describes the clinical usefulness of transdermal hormone replacement therapy. This route of administration is particularly important in women with hypertriglyceridemia, in hypertensive ... [more ▼]

This review describes the clinical usefulness of transdermal hormone replacement therapy. This route of administration is particularly important in women with hypertriglyceridemia, in hypertensive postmenopausal women, in women who smoke or have an increased risk of biliary or liver disorder, for those who display a reduced glucose tolerance or in women who are at risk of thrombotic disorders. The avoidance of the "first passage effect" is ensured by the transdermal application of estrogen and probably explains the superiority of this route of steroid administration. [less ▲]

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See detailHormonothérapie du cancer du sein
LIFRANGE, Eric ULg; ANDRE, Chantal ULg; BLERET, Valerie ULg et al

in Revue Médicale de Liège (2011), 66(5-6), 367-371

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See detailHorner syndrome in children: a clinical condition with serious underlying disease
Barrea, Christophe ULg; Vigouroux, Tiphaine ULg; Karam, Joe ULg et al

in Neuropediatrics (2016), 47(4), 268-272

Detailed reference viewed: 17 (3 ULg)