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See detailChanges in mediobasal hypothalamic gonadotropin-releasing hormone messenger ribonucleic acid levels induced by mating or ovariectomy in a reflex ovulator, the ferret.
Bakker, Julie ULg; Rubin, B. S.; Baum, M. J.

in Endocrinology (1999), 140(2), 595-602

The ferret is a reflex-ovulating species in which receipt of an intromission induces a prolonged (+/- 12 h) preovulatory LH surge in the estrous female. This LH surge is probably stimulated by a large ... [more ▼]

The ferret is a reflex-ovulating species in which receipt of an intromission induces a prolonged (+/- 12 h) preovulatory LH surge in the estrous female. This LH surge is probably stimulated by a large release of GnRH from the mediobasal hypothalamus (MBH). In Exp 1 we asked whether GnRH messenger RNA (mRNA) levels increase in response to mating so as to replenish the MBH GnRH stores needed to sustain the preovulatory LH surge. Estrous females were killed 0, 0.25, 0.5, 1, 3, 6, 14, or 24 h after the onset of a 10-min intromission from a male. Coronal brain sections ranging from the rostral preoptic area caudally to the posterior hypothalamus were processed for in situ hybridization using a 35S-labeled oligoprobe complementary to the human GnRH-coding region. We found no evidence of increased MBH GnRH mRNA levels during the ferret's mating-induced preovulatory LH surge. Instead, the number of GnRH mRNA-expressing cells dropped significantly in the arcuate region beginning 6 h after onset of intromission and remained low thereafter. Furthermore, cellular GnRH mRNA levels decreased in the arcuate region toward the end of the preovulatory LH surge. In Exp 2 we asked whether ovarian hormones regulate MBH GnRH mRNA levels in the female ferret. Ovariectomy of estrous females significantly reduced the number of GnRH mRNA-expressing cells in the arcuate region. This decrease was probably not due to the absence of circulating estradiol. Gonadally intact anestrous females had levels of MBH GnRH mRNA similar to those in estrous females even though plasma estradiol levels were equally low in anestrous females and ovariectomized females. Ovarian hormones other than estradiol may stimulate MBH GnRH mRNA levels in anestrous and estrous females. [less ▲]

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See detailChanges in mitral regurgitation and left ventricular geometry during exercise affect exercise capacity in patients with systolic heart failure.
Izumo, Masaki; Suzuki, Kengo; Moonen, Marie ULg et al

in European Journal of Echocardiography (2011), 12(1), 54-60

AIMS: exercise may dramatically change the extent of functional mitral regurgitation (MR) and left ventricular (LV) geometry in patients with chronic heart failure (CHF). We hypothesized that dynamic ... [more ▼]

AIMS: exercise may dramatically change the extent of functional mitral regurgitation (MR) and left ventricular (LV) geometry in patients with chronic heart failure (CHF). We hypothesized that dynamic changes in MR and LV geometry would affect exercise capacity. METHODS AND RESULTS: this study included 30 CHF patients with functional MR who underwent symptom-limited bicycle exercise stress echocardiography and cardiopulmonary exercise testing for quantitative assessment of MR (effective regurgitant orifice; ERO), and pulmonary artery systolic pressure (PASP). LV sphericity index was obtained from real-time three-dimensional echocardiograms. The patients were stratified into exercised-induced MR (EMR; n = 10, an increase in ERO by >/=13 mm(2)) or non-EMR (NEMR; n = 20, an increase in ERO by <13 mm(2)) group. At rest, no differences in LV volume and function, ERO, and PASP were found between the two groups. At peak exercise, PASP and sphericity index were significantly greater (all P < 0.01) in the EMR group. The EMR group revealed lower peak oxygen uptake (peak VO(2); P = 0.018) and greater minute ventilation/carbon dioxide production slope (VE/VCO(2) slope; P = 0.042) than the NEMR group. Peak VO(2) negatively correlated with changes in ERO (r = -0.628) and LV sphericity index (r = -0.437); meanwhile, VE/VCO(2) slope was well correlated with these changes (r = 0.414 and 0.364, respectively). A multivariate analysis identified that the change in ERO was the strongest predictor of peak VO(2) (P = 0.001). CONCLUSION: dynamic changes in MR and LV geometry contributed to the limitation of exercise capacity in patients with CHF. [less ▲]

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See detailChanges in mobility patterns as a factor for site density variation in the recent Epigravettian of northern Italy and Southeastern France
Naudinot, Nicolas; Tomasso, Antonin ULg; Tozzi, Carlo et al

in Journal of Archaeological Science (2014), 52

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See detailChanges in motor unit numbers in patients with ALS: a longitudinal study using the adapted multiple point stimulation method.
Wang, François-Charles ULg; Bouquiaux, Olivier ULg; De Pasqua, Victor ULg et al

in Amyotrophic Lateral Sclerosis & Other Motor Neuron Disorders (2002), 3(1), 31-8

METHOD: The adapted multiple point stimulation (AMPS) method for calculating motor unit numbers (MUNE) was applied in 12 patients with amyotrophic lateral sclerosis (ALS) before riluzole therapy (T(0 ... [more ▼]

METHOD: The adapted multiple point stimulation (AMPS) method for calculating motor unit numbers (MUNE) was applied in 12 patients with amyotrophic lateral sclerosis (ALS) before riluzole therapy (T(0)) and again after 4, 8 and 12 months of treatment. RESULTS: Paired Student's t-test indicated a significant decrease of thenar MUNE and compound muscle action potential (CMAP) size at each 4-monthly interval, while average surface motor unit potential (SMUP) size did not change significantly over time. The rate of motor unit (MU) loss at month 4 was more than 20% in six patients (group 1) and less than 20% in six other patients (group 2). Comparison of groups 1 and 2 by Mann-Whitney U-testing indicated that percent changes in thenar MUNE and CMAP size compared to baseline were significantly different at months 4, 8 and 12, while no difference between the two groups was found for average SMUP size variations. In the group with a slow rate of MU loss, CMAP size remained stable, while in the group with a rapid rate of MU loss, there was a dramatic reduction in size of the CMAP. A positive correlation was found between percent change in thenar MUNE at T(4) and at T(12) (P < 0.001). CONCLUSION: AMPS is a useful technique to document MUNE, SMUP size and CMAP size changes over time in patients with ALS. [less ▲]

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See detailChanges in naming and semantic abilities with aging from 50 to 90 years
Verhaegen, Clémence ULg; Poncelet, Martine ULg

in Journal of the International Neuropsychological Society (2013)

The aim of this study was to determine whether naming difficulties arise in individuals as young as their 50s. Participants of 25-35, 50-59, 60-69 and above 70 years of age were given a picture naming ... [more ▼]

The aim of this study was to determine whether naming difficulties arise in individuals as young as their 50s. Participants of 25-35, 50-59, 60-69 and above 70 years of age were given a picture naming task. To uncover subtle naming difficulties, latencies were analyzed in addition to accuracy. In order to control whether the expected slower naming latencies could be due to a general slowing affecting all cognitive tasks, participants were also given an odd/even judgment task to assess cognitive processing speed. The results confirmed that participants in their 50s presented decline in naming performance, reflected by an increase in naming latencies, whereas adults in their 60s and their 70s showed both a decrease in accuracy and an increase in latency. Moreover, the increase in naming latencies remained significant even after controlling for odd/even judgment latencies, suggesting a degradation specific to the picture naming task. We assumed that these slower latencies may result from a language-specific impairment. As a further test for language-specific degradation, participants’ semantic capacities were also assessed with a synonym judgment task and the Pyramids and Palm Trees test. The above-70 group showed semantic degradation. The contributions of multiple factors to naming difficulties in aging are discussed. [less ▲]

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See detailChanges in nitrogen source modify distribution of excitation energy in the cyanobacterium Phormidium laminosum
deAlda, JAGO; Tapia, M. I.; Franck, Fabrice ULg et al

in Physiologia Plantarum (1996), 97(1), 69-78

In an attempt to clarify the interactions between the available nitrogen source and the photosystems in cyanobacteria, O-2 exchange and fluorescence emission were monitored in spheroplasts and intact ... [more ▼]

In an attempt to clarify the interactions between the available nitrogen source and the photosystems in cyanobacteria, O-2 exchange and fluorescence emission were monitored in spheroplasts and intact cells of the non N-2-fixing cyanobacterium Phormidium laminosum (strain OH-1-p.Cl-1) growing on different nitrogen sources or in the absence of nitrogen. Short-term (time scale of seconds to minutes), NH4+ addition to NO3--growing or N-starved cells and, to a minor extent, NO3- addition to N-starved cells, induced state 2 transitions both in light and dark. Long term (time scale of days), the fluorescence yield of PSI relative to that of PSII at 77 K was higher in NO3-- than in NH4-+ growing cells, and even higher in N-starved cells. In the dark, the plastoquinone pool was more reduced in NH4-+ than in NO3--growing cells. Both PSII and PSI activities and the degree of linking between both photosystems were affected in the long term, so that non-cyclic electron transport decreased in parallel to the ferredoxin requirement to assimilate each nitrogen source. Results indicate that nitrogen metabolism exerts short- and long-term control over the photosynthetic apparatus, which acclimates to the energy requirement of the available nitrogen source. [less ▲]

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See detailChanges In Oxylipin Synthesis After Phytophthora Infestans Infection Of Potato Leaves Do Not Correlate With Resistance
Fauconnier, Marie-Laure ULg; Rojas-Beltran, J.; Dupuis, B. et al

in Plant Physiology and Biochemistry (2008), 46(8-9), 823-831

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See detailChanges in peroxidase activity, and level of phenolic compounds during light-induced plantlet regeneration from Eucalyptus camaldulensis Dehn. nodes in vitro
Arezki, Ouoimare; Boxus, Philippe; Kevers, Claire ULg et al

in Plant Growth Regulation (2001), 33(3), 215-219

Node cultures of Eucalyptus camaldulensis Dehn in Petri dishes in vitro under darkness in the presence of an auxin developed meristematic agglomerates (4 to 6 diameter), i.e. dense shoot clusters in which ... [more ▼]

Node cultures of Eucalyptus camaldulensis Dehn in Petri dishes in vitro under darkness in the presence of an auxin developed meristematic agglomerates (4 to 6 diameter), i.e. dense shoot clusters in which outgrowth of numerous successive buds is limited. Similar cultures under a 16 photoperiod produced small green plantlets with reduced leaves often presenting white hypertrophied lenticels and very short roots crowning the stem bases. The use of half-litre glass vials under light allowed direct development of well-developed rooted plantlets, either in the presence of the same auxin or in the presence of a cytokinin. Light favoured an increase in phenolic compounds and a reverse variation of peroxidase activity during the culture cycles. These aspects are discussed in terms of a possible regulation of the endogenous auxin level through a light control of peroxidase activity and the level of phenolic compounds. [less ▲]

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See detailChanges in physicochemical and rheological properties of commercial yogurts during storage.
Pop, Carmen; Apostu, Sorin; Rotar, Ancuta M. et al

Conference (2013)

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See detailChanges in pituitary responsiveness to luteinizing hormone-releasing hormone during an annual cycle in the domestic duck, Anas platyrhynchos L.
Balthazart, Jacques ULg; Willems, Jean; Hendricks, Jean Claude

in Journal of Experimental Zoology (The) (1980), 211(1), 113-23

On four occasions during an annual cycle, 5--7 male domestic ducks were injected with two different doses (5 and 20 micrograms) of synthetic luteinizing hormone-releasing hormone (LHRH) to study the ... [more ▼]

On four occasions during an annual cycle, 5--7 male domestic ducks were injected with two different doses (5 and 20 micrograms) of synthetic luteinizing hormone-releasing hormone (LHRH) to study the possible changes in responsiveness of the pituitary. The luteinizing hormone (LH) and the follicle-stimulating hormone (FSH) were measured in the plasma samples collected after these injections. The induced release of LH changes from one period of the year to another, being minimum in March at the height of the reproductive season. The LHRH injection also induces the release of some FSH but only in limited amounts. The changes in pituitary responsiveness to LHRH are negatively correlated to changes in the circulating LH level (it is high when the plasma LH is low and vice versa). This suggests that the hypothalamic synthesis and release of LHRH must also change during the year. [less ▲]

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See detailChanges in plankton dynamics and biodiversity in the oligotrophic Bay of Calvi (Corsica, Northwestern Mediterranean): response to climate change
Goffart, Anne ULg; Hecq, Jean-Henri ULg

Conference (2008)

The development of the winter-spring phytoplankton bloom is investigated in the Bay of Calvi (Corsica, Ligurian Sea, Northwestern Mediterranean) since 1979. A drastic reduction of phytoplankton biomass is ... [more ▼]

The development of the winter-spring phytoplankton bloom is investigated in the Bay of Calvi (Corsica, Ligurian Sea, Northwestern Mediterranean) since 1979. A drastic reduction of phytoplankton biomass is evidenced over the last three decades. Changes in phytoplankton dynamics and biodiversity are discussed in relation to long-term changes in wind stress, NAO conditions and environmental conditions. As a consequence, time-series results enlighten that the entire food web dynamics is affected and that ecosystem resilience is threatened. [less ▲]

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See detailChanges in polyamines, auxins and peroxidase activity during in vitro rooting of Fraxinus angustifolia shoots: an auxin-independent rooting model
Tonon, Giustino; Kevers, Claire ULg; Gaspar, Thomas ULg

in Tree Physiology (2001), 21(10), 655-663

Among shoots of Fraxinus angustifolia Vahl raised in vitro, 76% rooted after culture on root induction medium for 5 days in darkness followed by culture on root expression medium for 15 days in light. The ... [more ▼]

Among shoots of Fraxinus angustifolia Vahl raised in vitro, 76% rooted after culture on root induction medium for 5 days in darkness followed by culture on root expression medium for 15 days in light. The addition of 20.7 muM indole-butyric acid (IBA) to the root induction medium did not significantly increase the rooting percentage (88%). Putrescine, spermidine, cyclohexylamine (CHA) and aminoguanidine (AG) enhanced rooting up to 100% (98.66% for AG), when applied during root induction in the absence of IBA, otherwise these compounds inhibited rooting, as did spermine and difluoromethylornithine (DFMO) + difluoromethylarginine (DFMA). The root induction phase was characterized by a temporary increase in endogenous free indole-acetic acid (IAA) and putrescine concentrations during root induction, whereas the root expression phase was characterized by increased peroxidase activity and low concentrations of polyamines. These changes were specifically associated with the rooting process and did not depend on the presence of exogenous IBA, because application of exogenous IBA enhanced the amount of IAA in the cuttings but did not affect rooting or the pattern of changes in polyamines and peroxidase. The effects of CHA, AG and DFMO + DFMA on endogenous concentrations of auxins and polyamines highlight the close relationship between the effects of IAA and putrescine in root induction and suggest that polyamine catabolism has an important role in root formation and elongation. [less ▲]

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See detailChanges in Progesterone Metabolism in the Chicken Hypothalamus During Induced Egg Laying Stop and Molting
Balthazart, Jacques ULg; Verheyen, G.; Schumacher, M. et al

in General and Comparative Endocrinology (1988), 72(2), 282-95

In the present study, we have established and validated a radioenzyme assay which permits us to quantify progesterone metabolism in the chicken brain. Progesterone metabolism was then studied in five ... [more ▼]

In the present study, we have established and validated a radioenzyme assay which permits us to quantify progesterone metabolism in the chicken brain. Progesterone metabolism was then studied in five brain areas obtained by microdissection from the telencephalon (part of the lobus paraolfactorius immediately rostral to the preoptic area), the preoptic area, and the hypothalamus. Three metabolites of progesterone were produced in large amounts in these brain regions and were quantified in this study: 5 beta-pregnane-3,20-dione (5 beta-DHP) as well as its metabolite 3 alpha-hydroxy-5 beta-pregnane-20-one (5 beta,3 alpha-ol) and 5 alpha-pregnane-3,20-dione (5 alpha-DHP). The unmetabolized progesterone was also recovered and quantified. The 5 beta-reduction of progesterone (production of 5 beta-DHP and 5 beta,3 alpha-ol) was very active but its 5 alpha-reduction (production of 5 alpha-DHP) was almost absent in the lobus paraolfactorius. An opposite pattern of metabolism was found in the preoptic area and the hypothalamus (higher 5 alpha- but lower 5 beta-reductase activity). The changes in progesterone metabolism in these brain areas were then studied in groups of hens submitted to induced egg laying stop and molting. A significant decrease in progesterone 5 alpha-reduction was found in the median hypothalamus of hens during the period of molt. Simultaneously, the experimental procedures induced significant decreases in the production of 5 beta-DHP by the lobus paraolfactorius, anterior, and medial hypothalamus but induced a significant increase in the production of this metabolite in the preoptic area. These changes are likely to be involved in the control of reproductive functions including sexual behavior and secretion of luteinizing hormone-releasing hormone, and a number of possible causal mechanisms are presented. These should now be tested experimentally especially in view of the very limited information which is now available on the biological effects of the metabolites of progesterone. [less ▲]

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See detailChanges in pubertal timing: Past views, Recast issues
Bourguignon, Jean-Pierre ULg; Domine, Françoise; Glowacz, Fabienne ULg et al

in Bourguignon, Jean-Pierre; Carel, Jean-Claude; Christen, Yves (Eds.) Brain Crosstalk in Puberty in Adolescence (2015)

Abstract The aim of this article is to review some common opinions on changes in pubertal timing and shed new light both on the indicators used in assessing pubertal timing and the underlying mechanisms ... [more ▼]

Abstract The aim of this article is to review some common opinions on changes in pubertal timing and shed new light both on the indicators used in assessing pubertal timing and the underlying mechanisms. While emphasis is usually on advancement in timing of female puberty, it appears that timing also changes in males, both towards earliness for the initial pubertal stages and towards lateness for the final stages. Such findings suggest that the environmental influences on pubertal timing are more complex than initially thought. Moreover, self-evaluated pubertal timing versus peers provides information that is not always consistent with observations at physical examination, suggesting that both perspectives should be considered, especially when studying the correlation between pubertal timing and psychosocial aspects. The mechanisms of changes in pubertal timing may involve both central neuroendocrine control and peripheral effects in tissues targeted by gonadal steroids. Though energy availability is certainly a clue to the mechanism of pubertal development, changes in the control of both energy balance and control of reproduction may vary under the influence of common determinants such as endocrine-disrupting chemicals. These effects can take place right before puberty as well as much earlier, during fetal and neonatal life. Finally, environmental factors can interact with genetic factors in determining changes in pubertal timing. Therefore, the variance in pubertal timing is no longer to be considered under the absolutely separate control of environmental and genetic determinants.  [less ▲]

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See detailChanges in pulse pressure, heart rate and the pulse pressure x heart rate product during squatting in Type 1 diabetes according to age.
Philips, Jean-Christophe ULg; Marchand, Monique ULg; Scheen, André ULg

in Diabetic Medicine : A Journal of the British Diabetic Association (2010), 27(7), 753-61

AIMS: We assessed changes in pulse pressure and heart rate during a squatting test, as indirect markers of arterial stiffness and cardiovascular autonomic neuropathy, respectively, according to age and ... [more ▼]

AIMS: We assessed changes in pulse pressure and heart rate during a squatting test, as indirect markers of arterial stiffness and cardiovascular autonomic neuropathy, respectively, according to age and sex in patients with Type 1 diabetes mellitus. METHODS: We evaluated 160 diabetic patients, divided into four groups of 20 men and 20 women according to age (G1, 20-30 years old; G2, 31-40 years old; G3, 41-50 years old; and G4, 51-60 years old), and 160 non-diabetic matched control subjects. Each subject underwent a 3 min posture test (standing-squatting-standing) with continuous measurement of arterial blood pressure and heart rate by a Finapres device. Overall values throughout the test, baseline levels in initial standing position and squatting-induced changes in pulse pressure, heart rate and the pulse pressure x heart rate product were compared between diabetic patients and healthy control subjects. RESULTS: In the standing position, a greater increase in pulse pressure and lower reduction in heart rate with age led to a significantly higher pulse pressure x heart rate product in diabetic patients compared with control subjects. In the squatting position, a more marked pulse pressure increase in the absence of appropriate reduction in heart rate resulted in a greater rise in the pulse pressure x heart rate product in diabetic patients than in healthy subjects. No major differences were noted between the sexes, with the exception of a stronger relationship between pulse pressure and age in the female population with diabetes. Squatting-derived indices of cardiovascular autonomic neuropathy were also noted with increasing age in diabetic patients. CONCLUSIONS: The marked increase in the pulse pressure x heart rate product ('pulsatile stress') according to age, combined with cardiovascular autonomic neuropathy, may contribute to the higher cardiovascular risk of patients with Type 1 diabetes. [less ▲]

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See detailChanges in respiratory mechanics measured by IOS during the first day of life in calves
Uystepruyst, Ch; Reinhold, P.; Coghe, J. et al

in Proceedings: 17th Symposium of the Comparative Respiratory Society (1999)

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See detailChanges in Serum Concentrations of Steroids During Embryonic and Post-Hatching Development of Male and Female Japanese Quail (Coturnix Coturnix Japonica)
Schumacher, M.; Sulon, Joseph ULg; Balthazart, Jacques ULg

in Journal of Endocrinology (1988), 118(1), 127-34

Serum concentrations of testosterone, 5 alpha-dihydrotestosterone, oestradiol and progesterone were measured by radioimmunoassay combined with Celite chromatography in male and female Japanese quail ... [more ▼]

Serum concentrations of testosterone, 5 alpha-dihydrotestosterone, oestradiol and progesterone were measured by radioimmunoassay combined with Celite chromatography in male and female Japanese quail (Coturnix coturnix japonica) during the second half of embryonic life (days 9-17 of incubation) and during the first 5 weeks after hatching. The mean level of each of the four steroids was significantly affected by the age of the birds. An overall effect of sex was detected by analysis of variance only on oestradiol concentrations, with females having higher serum concentrations than males during most of the age range studied. Significant peaks of testosterone and progesterone were also detected around hatching time. These results are consistent with the view that oestradiol is the major hormone implicated in the sexual differentiation of reproductive behaviour in the quail. The relationships between the circulating concentrations of oestradiol during ontogeny and the critical period of differentiation as postulated by currently accepted models is also discussed. [less ▲]

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