References of "Beckers, Jean-François"
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See detailPregnancy-Associated Glycoprotein and Progesterone Concentrations during Pregnancy Failure in Bedouin Goat from the Southwest of Algeria.
Charallah, Salima; Amirat, Z.; Sulon, Joseph et al

in Reproduction in Domestic Animals (2010), 45(6), 213-238

Contents Thirteen female Bedouin goats living in arid land of Algeria Sahara desert were used in this study. These goats were pregnant but they sustained an abortion because of unidentified causes. None ... [more ▼]

Contents Thirteen female Bedouin goats living in arid land of Algeria Sahara desert were used in this study. These goats were pregnant but they sustained an abortion because of unidentified causes. None of the goats showed any signs of general disease. Plasma concentrations of caprine pregnancy-associated glycoproteins (cPAGs) and progesterone (P4) were determined during pregnancy using radioimmunoassay. The cPAGs concentration was undetectable (<0.8 ng/ml) throughout the first 2 weeks of gestation. From week 3 after mating, cPAGs concentration was detectable with significant individual variations (p < 0.05) reaching a maximum secretion (436.1 ng/ml). Throughout gestation, cPAGs concentration remained relatively constant but decreased few days before abortion, on an average of 9.2 +/- 1.2 days (n = 11), except for two females where the concentrations decreased later (1-2 days before abortion). One or two peaks of cPAGs concentrations (in 4/13 and in 9/13 females, respectively) have been measured few weeks before abortion (77-124 days after mating), when a decline of cPAGs was detected. The P4 concentration increased after mating, and was high from the first week till the end of pregnancy. The P4 concentration (9.1 +/- 0.9 ng/ml) decreased rapidly (<0.5 ng/ml) after 4 +/- 0.7 days (n = 6) or 9.4 +/- 1.6 days (n = 7) before abortion. A positive relationship (p < 0.01) was found between P4 and cPAGs concentrations during gestation. Results indicate that cPAGs and P4 measurements can be used for monitoring gestation and for abortion prediction. [less ▲]

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See detailLate embryonic and early fetal mortalities in dairy cows: the incidence and pregnancy protein profiles.
Karen, A.; Bajcsy, A. C.; Kovacs, R. et al

in Proceedings of the 20th International Congress of Hungarian Association for Buiatrics. (2010, October 20)

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See detailEffect of a corpus luteum with or without a cavity on fertility in dairy cows after prostaglandin treatment
Repasi, A.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

in Proceedings of the Hungarian Association for Buiatrics (2010, October)

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See detailCould Western blot analysis be an alternative to radio-immunoassay for sheep pregnancy associated glycoproteins measurements ?
El Amiri, B.; El Abbadi, N.; Benjelloun, B. et al

in Reproduction in Domestic Animals (2010, September 15), 45(Suppl 3), 65

This study prospected whether Western blot analysis could be an alternative to radio-immunoassay (RIA) for sheep pregnancy diagnosis. Blood samples were taken from Boujaâd ewes (n= 9) and Boujaâd x D’man ... [more ▼]

This study prospected whether Western blot analysis could be an alternative to radio-immunoassay (RIA) for sheep pregnancy diagnosis. Blood samples were taken from Boujaâd ewes (n= 9) and Boujaâd x D’man (BD) cross breed (n= 12). The pregnancy associated glycoproeins (PAGs) were weekly monitored in plasma during the whole gestation and the first month postpartum by two RIA systems (El Amiri et al., 2007, Reprod Domest Anim 42:257-62). The highly immunoreactive samples derived from PAG profiles were tested using Western blot based on the same antiserum used in RIA. Each week (from the 13th to the 19th week), two pools of plasma samples (4 ml each) were taken from single and multiple lambing ewes respectively. Samples were submitted to a protein extraction at neutral pH, followed by ammonium sulfate (A.S.) precipitation, dialysis, and lyophilization. The placental extract was used as a check. Results revealed that ewes with multiple lambs presented numerically higher PAG concentrations. In both RIA systems, the high concentrations were recoded around the 19th week of gestation and the maximal concentrations varied from 120 to 700 ng/ml. In Western blot, the placental extracts reacted positively while the plasma samples did not give any positive reaction. In conclusion, the RIA remains the only sensitive method to measure PAGs in plasma. The present study strengthens the need to develop an ELISA kit as an alternative to RIA systems. [less ▲]

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See detailMonitoring endocrine profiles for prediction of stillbirth in Holstein-Friesian dairy cattle
Szenci, O.; Bajcsy, A. C.; Brydl, E. et al

Conference (2010, September 03)

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See detailDiagnostico precoz de gestation en Ganado ovino mediante un kit enzimoimmunoanalisis (EIA) de la glicoproteina asociada a la gestation (PAG) plasmatica.
Alabart, J. L.; Lahoz, B.; Folch, J. et al

in Proceedings of the XXXV Congreso de la Sociedad Espanola de Ovinotechnia y Caprinotecnia (SEOC) (2010, September)

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See detailCan we predict troubles during horse clinical examination by a simple test?
Peeters, Marie ULg; Godfroid, Sandra; Sulon, Joseph et al

Poster (2010, August 03)

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See detailPreliminary results obtained by ria determination of the proteins associated to pregnancy (PAG) in goat and sheep
Zamfirescu, S; Nadolu, D; Beckers, Jean-François ULg

in Annals of the Romanian Society for Cell Biology (2010), XV(1), 98-104

In goat and sheep, the glycoproteins associated to pregnancy (PAG) are little studied. Their study in these species is very important in the evaluation of prediction of early pregnancy. Even though ... [more ▼]

In goat and sheep, the glycoproteins associated to pregnancy (PAG) are little studied. Their study in these species is very important in the evaluation of prediction of early pregnancy. Even though numerous research has been done in order to investigate the physiological functions of placental proteins, the exact biofunction of the glycoproteins associated to pregnancy is still unknown. The objective of research was the study of the dynamics of PAG in goats and ewes in the first part of pregnancy(1-35 days after mating) and the determination of correlations with the reproductive status of females and to earlier the pregnancy.The experiment was realized on 49 Saanen x Carpatina goats and 72 Merinos of Palas sheep from the biostation of the Research and Development Institute for Goat and Sheep, Palas Constanta. The females in normal reproduction season were monitored for the detection of estrus and mated naturally. The blood was collected by puncture of the jugular vein on days 0, 7, 14, 25 and 35 after mating (day 0). The serum was obtained after centrifuging at 1500 x g for 15 minutes and stored at -20oC till the RIA determination. The RIA of the plasma with the purpose of detecting the concentration of proteins specific to pregnancy was realized in two experimental series in February and December 2008, at the Laboratory for Reproduction Physiology – The Faculty of Veterinary Medicine, Liege, Belgium. The RIA dosing was realized after the application of the method with the preincubation of the serums to test with specific serum (Atg°) and then with the marked antigen (Atg*), considering the high sensitivity of this method to detect the smallest values of PAG from day 0 to day 35 after mating. The diagnosis of the pregnancy state was based on the principle of PAG antibodies binding to the specific antigen, establishing through RIA the quantity of free antigen. Non-pregnancy involves the attachment of the antigen marked by non-specific antibodies. The preliminary results have demonstrated that the sheep PAG were had values ranging between 4.197-15.985 ng/ml and 0.01-3.39 ng/ml in nonpregnant ewes. In the pregnant goats, the PAG concentrations ranged between 16.75±3.44-27.17±2.95 ng/ml, while in the nonpregnant goats, the PAG values were 1.38±0.35 – 2.03±0.51 6 ng/ml. The purpose of the experiments was to find one accurate method for early pregnancy diagnosis in goat and sheep. The conclusion was that ovine pregnancy can be reliably diagnosed on Day 25 after AI and goat pregnancy on Day 30, by using a heterologous radioimmunoassay of PAG. [less ▲]

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See detailEfficiency of day seven collection of bovine embryosafter superovulation by flushing the oviducts and the uterin horns.
Havlicek, V.; Kuzmany, A.; Beckers, Jean-François ULg et al

in Reproduction, Fertility and Development (2010), 22(1), 363

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See detailEffect of exogenous circulating anti-bPL antibodies on bovine placental lactogen measurements in foetal samples.
Alvarez Oxiley, Andrea Vivian ULg; Melo de Sousa, Noelita ULg; Hornick, Jean-Luc ULg et al

in Acta Veterinaria Scandinavica (2010), 52

BACKGROUND: The involvement of placental lactogen (PL) in the regulation of foetal growth has been investigated in different species by in vivo immunomodulation techniques. However, when circulating ... [more ▼]

BACKGROUND: The involvement of placental lactogen (PL) in the regulation of foetal growth has been investigated in different species by in vivo immunomodulation techniques. However, when circulating antibodies are present together with the hormone, the procedure for hormonal measurement becomes considerably complex. The aim of this study was the immunoneutralization of bovine placental lactogen (bPL) concentrations in bovine foetal circulation by direct infusion of rabbit anti-bPL purified immunoglobulins (IgG) via a foetal catheter (in vivo study). The ability of a RIA based on guinea pig anti-bPL antiserum, for the measurement of bPL concentrations in samples containing exogenous rabbit anti-bPL immunoglobulins, was also analyzed in in vitro and in vivo conditions. METHODS: Six bovine foetuses were chronic cannulated on the aorta via the medial tarsal artery. Infusion of rabbit anti-bPL IgG was performed during late gestation. Pooled rabbit anti-bPL antisera had a maximal neutralization capacity of 25 microg bPL/mL of immunoglobulin. Interference of rabbit anti-bPL immunoglobulin with radioimmunoassay measurement using guinea pig anti-bPL as primary antibody was first evaluated in vitro. Polyclonal anti-bPL antibodies raised in rabbit were added in foetal sera to produce 100 samples with known antibodies titers (dilutions ranging from 1:2,500 till 1:1,280,000). RESULT(S): Assessment of the interference of rabbit anti-bPL antibody showed that bPL concentrations were significantly lower (P < 0.05) in samples added with dilutions of rabbit antiserum lower than 1:80,000 (one foetus) or 1:10,000 (four foetuses). It was also shown that the recovery of added bPL (12 ng/mL) was markedly reduced in those samples in which exogenous rabbit anti-bPL were added at dilutions lower than 1:20,000. Concentrations of foetal bPL were determined in samples from cannulated foetuses. In foetuses 1 and 6, bPL concentrations remained almost unchanged (<5 ng/mL) during the whole experimental period. In Foetus 3, bPL concentrations decreased immediately after IgG infusion and thereafter, they increased until parturition. CONCLUSION(S): The use of a bPL RIA using a guinea pig anti-bPL as primary antiserum allowed for the measurement of bPL concentrations in foetal plasma in presence of rabbit anti-bPL IgG into the foetal circulation. Long-term foetal catheterization allowed for the study of the influence of direct infusion of anti-bPL IgG on peripheral bPL concentrations in bovine foetuses. [less ▲]

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See detailComparison of accuracy of sonography, rectal palpation, and pregnancy-associated glycoproteins tests for pregnancy diagnosis in cows
Gajewski, Z.; Petrajtis, M.; Melo de Sousa, Noelita ULg et al

in Proceedings of the XIth Middle European Buiatrics Congress (2010)

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See detailPrediction of stillbirth by monotoring endocrine and metabolic parameters in dairy cattle
Szenci, 0; Bajcsy, A. C.; Brydl, E. et al

in Reproduction in Domestic Animals (2010), 45(Suppl 3), 109

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See detailLe système de contrôle du chant des passériformes : un modèle d’étude de la plasticité neuronale
Boseret, Géraldine ULg; Beckers, Jean-François ULg

in Annales de Médecine Vétérinaire (2010), 154(1), 48-60

In many songbirds species, wherein we can find the domestic canary (Serinus canaria), singing is generally produced either to defend a territory or to attract a mate. The Song Control System is a neural ... [more ▼]

In many songbirds species, wherein we can find the domestic canary (Serinus canaria), singing is generally produced either to defend a territory or to attract a mate. The Song Control System is a neural specialization, mostly located in telencephalic regions of the brain and associated to the control of song learning, perception and production. External factors such as testosterone (T), photoperiod and social cues have been described to modulate singing behaviour. Parallel to the song behaviour, some of the song control system nuclei (HVC, RA and Area X) demonstrate a puzzling amount of seasonal plasticity. Their volumes varies seasonally based on changes in cell spacing, neuropile size, dendritic arborisation and in the case on the nidopallial nucleus HVC on the incorporation of newborn neurons. We present here a review of this curious phenomenon of adult neuroplasticity associated to a complex behaviour, which doesn’t occur as far as we know in the mammalian adult brain [less ▲]

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See detailMonitoring endocrine profiles for prediction of stillbirth in Holstein-Friesian dairy cattle
Szenci, O.; Bajcsy, A. C.; Bryd, E. et al

Poster (2010)

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See detailNeospora caninum and coxiella burnetii seropositivity are related to endocrine pattern changes during gestation in lactating dairy cows.
Garcia-Ispierto, I.; Nogareda, C.; Yaniz, J. L. et al

in Theriogenology (2010), 74(2), 212-230

Q fever is a zoonotic infection caused by Coxiella burnetii that is endemic worldwide. Domestic ruminants are a source of infection for humans. Given the suggestion that the bacterium recrudesces during ... [more ▼]

Q fever is a zoonotic infection caused by Coxiella burnetii that is endemic worldwide. Domestic ruminants are a source of infection for humans. Given the suggestion that the bacterium recrudesces during pregnancy in cattle, this study was designed to determine whether C. burnetii infection affects hormonal patterns, such as progesterone, cortisol, pregnancy associated glycoproteins (PAG), and prolactin during gestation in lactating cows. Possible interactions with Neospora caninum were also explored. The study was performed on 58 gestating non-aborting cows. Blood samples for hormone determinations were collected on Days 40, 90, 120, 150, 180, and 210 of gestation. For antibody determinations, blood was collected at day 40 postinsemination and postpartum. By GLM repeated measures analysis of variance, we established the effects of production and reproductive variables as well as Coxiella and Neospora seropositivity related to changes on cortisol, PAG, progesterone, and prolactin levels. Coxiella antibody levels were significantly related to cortisol, PAG, and plasma progesterone concentrations, whereas Neospora seropositivity was linked to plasma progesterone concentrations. The interaction between Coxiella and Neospora seropositivity was correlated with cortisol and plasma progesterone levels, whereas the interaction seropositivity against C. burnetii-plasma cortisol concentration was related to plasma PAG levels. Finally, an effect of lactation number only was observed on plasma prolactin. Our findings suggest that both the N. caninum and C. burnetii infection or the presence of both modify endocrine patterns throughout gestation. Cows seropositive to both, Neospora and Coxiella, showed higher plasma progesterone levels than the remaining animals examined. Seropositivity to C. burnetii was associated with placental damage and diminishing PAG levels throughout the second half of gestation, along with increased plasma cortisol levels on Day 180 of gestation. [less ▲]

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See detailPregnancy-associated Glycoprotein Profile during the First Trimester of Pregnancy in Egyptian Buffalo Cows.
El-Battawy, K. A.; Melo de Sousa, Noelita ULg; Szenci, Otto et al

in Reproduction in Domestic Animals (2009), 44(2), 161166

Pregnancy-associated glycoprotein (PAG) concentrations were measured in buffalo cows starting from day 28 after breeding. Oestrus was synchronized in 10 buffaloes using two injections of 25 mg ... [more ▼]

Pregnancy-associated glycoprotein (PAG) concentrations were measured in buffalo cows starting from day 28 after breeding. Oestrus was synchronized in 10 buffaloes using two injections of 25 mg prostraglandin (PG)F(2alpha) (Lutalyse((R))) at a 11-day interval. Blood sampling was conducted nearly twice weekly. Results indicated that plasma PAG concentrations in non-pregnant buffaloes were low (<0.20 ng/ml) during the whole experimental period (day 28 to 103), while in pregnant animals plasma PAG levels increased from day 28 (4.48 +/- 0.92 ng/ml) until day 41 (27.27 +/- 6.74 ng/ml), remaining high (20.71 +/- 9.20 ng/ml) until day 103. Progesterone levels were significantly (p < 0.0001) higher in pregnant (3.51-4.80 ng/ml) than in non-pregnant buffaloes (0.28-1.52 ng/ml). A significant difference (p < 0.0001) in plasma PAG concentrations between pregnant and non-pregnant animals starting at day 28 after breeding suggests that PAG-radioimmunoassay could be suitable for pregnancy diagnosis in buffaloes during this period. In conclusion, PAG test offers the advantages that it requires a single plasma sample for early pregnancy diagnosis as well as the accuracy of the test for the detection of pregnancy as early as day 28. [less ▲]

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See detailMicroscopic study of equine oocyte maturation within quaternary follicles.
Ponthier, Jérôme ULg; Beckers, Jean-François ULg; Deleuze, Stefan ULg

Conference (2009, February 19)

In various species a relationship between oocyte maturity and morphological characteristics of oocytes has been established. To our knowledge, immature oocyte aspect under light microscopy has been paid ... [more ▼]

In various species a relationship between oocyte maturity and morphological characteristics of oocytes has been established. To our knowledge, immature oocyte aspect under light microscopy has been paid little attention in the equine. The aim of the study is to give a general description and analyse microscopic parameters of immature oocytes. Follicles from abattoir ovaries are punctured after measurement of their diameter and their cumulus-oocyte complexes are recovered. Different characters such as oocyte diameter, cumulus aspect, granulosity and polarity of ooplasm are observed under light microscopy. No correlation between estral activity, follicle maturity, cumulus cells aspect, polarity and granulosity of ooplasm was observed. Thickness of zona pellucida differs between oocytes with polar or non polar ooplasm. No correlation was observed between follicle diameter and oocyte diameter and none of the other studied parameters showed an influence on oocyte diameter. Results show that no character of oocytes observed under light microscopy can be related to follicular origin or to any other character. Further studies have to be done to compare these immature oocytes with mature oocytes and to find the ultra-structural origin of characters observed under light microscopy. [less ▲]

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See detailDetection of placental lactogens in Swamp buffalo by radioimmunoassay technique.
Hanh, N. V.; Huu, Q. X.; Uoc, N. T. et al

in Reproduction, Fertility and Development (2009), 21(1), 152-153

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See detailDetection of placental lactogens in swamp buffalo by radioimmunoassay technique
Hanh, N. V.; Huu, Q. X.; Uoc, N. T. et al

in Reproduction, Fertility and Development (2009), 21(1), 152-153

Ruminant placental lactogens (PL) are members of the growth factor/prolactin (GH/PRL) family. They are synthesized by trophectodermal binucleate cells. There is evidence to suggest that PL is involved in ... [more ▼]

Ruminant placental lactogens (PL) are members of the growth factor/prolactin (GH/PRL) family. They are synthesized by trophectodermal binucleate cells. There is evidence to suggest that PL is involved in control of fetal growth, through actions in both the maternal and fetal compartments, as well as in influencing mammary growth during pregnancy (Byatt JC et al. 1992 J. Anim. Sci. 70, 2911–2923). The structure and biology of PL have been studied in the cow, sheep, goat, human, and mice. The maternal concentration of PL is 100- to 1 000-fold greater in pregnant sheep and goats than in cows but no information exists about PL concentration in buffalo. The aim of the present study was to evaluate the ability to detect PL in buffalo fluids by using bovine PL antibody. Samples were collected in the slaughterhouse immediately after animal slaughter. The fetuses were measured after heart blood collection. A bPL RIA system was used to determine the bPL concentrations in the buffalo samples (Alvarez-Oxiley AV et al. 2007 Reprod. Fertil. Dev. 19, 877–885). The rbPL molecules were radio-iodinated with [125]I-Na by using the lactoperoxidase method (Thorell JI and Johansson BG 1971 Biochim. Biophys. Acta 251, 363–369). Concentrations of buffalo PL are presented in Table 1. In this RIA system, the minimum detected value was 0.068 ng mL–1, and the binding competition curves of bovine PL standard and buffalo fluids dilution using bovine PL antibody were paralleled in all kinds of samples. The lowest concentration was detected in allantoid fluid and the greatest concentration in fetal plasma (P < 0.05). Study of the biology of PL in buffalo has proved difficult because the concentration of PL in all buffalo fluids is very low. Furthermore, the research concerning buffalo PL function required in vivo experiments. Existing data suggest that at least the concentration of buffalo PL is different from cattle and other smaller domestic ruminants. In conclusion, our results provide preliminary information about concentrations of PL in buffalo fluids. [less ▲]

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