References of "Beckers, Jean-François"
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See detailFactors affecting plasma progesterone in the early fetal period in high producing dairy cows.
Bech-Sabat, G.; Lopez-Gatius, F.; Yaniz, J. L. et al

in Theriogenology (2008), 69(4), 426-32

The aim of the present study was to determine whether certain animal- or management related factors could affect plasma progesterone concentrations on Day 42 of gestation in high producing dairy cows ... [more ▼]

The aim of the present study was to determine whether certain animal- or management related factors could affect plasma progesterone concentrations on Day 42 of gestation in high producing dairy cows. Factors affecting early fetal loss were also analyzed. The study population was comprised of 199 pregnant cows classified as having high (> or =9 ng/ml) or low (<9 ng/ml) plasma progesterone concentrations. Through logistic regression procedures it was determined that, based on the odds ratio, cows with two or more corpora lutea were three times more likely to have high progesterone concentrations than cows with a single corpus luteum. Low producing cows during the warm season were 2.86 times more likely to have high progesterone concentrations than the remaining cows. Primiparous cows with high concentrations (>4 ng/ml) of pregnancy associated glycoprotein-1 (PAG-1) were 2.73 times more likely to have high progesterone concentrations than the remaining cows. Of the 199 pregnancies, 25 (12.6%) suffered early fetal loss: 22/136 (16.2%) during the warm season and 3/63 (4.8%) during the cool season, all in cows without additional corpora lutea. Based upon the odds ratio, cows without an additional corpus luteum were 3.67 times more likely to suffer fetal loss during the warm season than during the cool season. Our results indicate that milk production, the presence of two or more corpora lutea and plasma PAG-1 concentrations can affect plasma progesterone concentrations at the onset of the fetal period. The presence of an additional corpus luteum strongly diminished the risk of early fetal loss during the warm period. [less ▲]

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See detailIsolation of new pregnancy-associated glycoproteins from water buffalo (Bubalus bubalis) placenta by Vicia villosa affinity chromatography.
Barbato, O.; Melo de Sousa, Noelita ULg; Klisch, K. et al

in Research in Veterinary Science (2008), 85(3), 457-66

The present study describes the isolation and characterization of new pregnancy-associated glycoprotein molecules (PAG) from midpregnancy and late-pregnancy placentas in the water buffalo (Bubalus bubalis ... [more ▼]

The present study describes the isolation and characterization of new pregnancy-associated glycoprotein molecules (PAG) from midpregnancy and late-pregnancy placentas in the water buffalo (Bubalus bubalis). After extraction, the homogenates are subjected to acid and ammonium sulfate precipitations followed by DEAE chromatography. Subsequently, the water buffalo PAG (wbPAG) from these solutions are enriched by Vicia villosa agarose (VVA) affinity chromatography. As determined by western blotting with anti-PAG sera, the apparent molecular masses of the immunoreactive bands from the VVA peaks range from 59.5 to 75.8kDa and from 57.8 to 73.3kDa in the midpregnancy and late-pregnancy placentas, respectively. Amino-terminal microsequencing of the immunoreactive proteins has allowed the identification of three distinct wbPAG sequences, which have been deposited in the SwissProt database: RGSXLTIHPLRNIRDFFYVG (acc. no. P85048), RGSXLTILPLRNIID (acc. no. P85049), and RGSXLTHLPLRNI (acc. no. P85050). Their comparison to previously identified proteins has shown that two of them are new because they have not been described before. Our results confirm the suitability of VVA chromatography for the enrichment of the multiple PAG molecules expressed in buffalo placenta. [less ▲]

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See detailPregnancy incidence in Norwegian red cows using nonreturn to estrus, rectal palpation, pregnancy-associated glycoproteins, and progesterone.
Garmo, R. T.; Refsdal, A. O.; Karlberg, K. et al

in Journal of Dairy Science (2008), 91(8), 3025-3033

The objectives of the study were to estimate pregnancy incidence and calving rate after first artificial insemination (AI) in Norwegian Red cows undergoing spontaneous estrus, to assess the relationship ... [more ▼]

The objectives of the study were to estimate pregnancy incidence and calving rate after first artificial insemination (AI) in Norwegian Red cows undergoing spontaneous estrus, to assess the relationship between pregnancy and management factors at herd or cow level, to evaluate differences between 60-d nonreturn rate (NRR60d) and pregnancy incidence, and to compare the accuracy of pregnancy diagnosis by rectal palpation and plasma pregnancy-associated glycoproteins (PAG) analysis supported by progesterone measurements. In total, 829 animals (n = 229 heifers, 234 first-lactation, 173 second-lactation, and 193 >second-lactation cows) were included. Milk samples for progesterone analysis were collected both at AI and 3 wk later. Cows with progesterone concentrations <3 ng/mL at AI were considered in estrus or having nonactive ovaries, whereas cows with progesterone concentrations >7 ng/ mL 3 wk later were considered pregnant. Blood sampling for PAG analysis and pregnancy diagnosis by rectal palpation were conducted 57.6 +/- 0.92 d after AI. Pregnancy-associated glycoprotein concentrations equal to 2.5 ng/mL gave the greatest sensitivity (94.3%) and specificity (94.6%) in the assessment of pregnancy. The number of days from calving to first AI was 85.3 +/- 1.71. Overall NRR60d after first AI was 72.5%. The corresponding values for heifers, first-lactation, second-lactation, and >second-lactation cows were 76.9, 67.1, 69.9, and 76.2%. Overall pregnancy incidence after first AI was 63.7%. The corresponding values for heifers, first-lactation, second-lactation, and >second-lactation cows were 70.0, 58.2, 61.6, and 64.9%. Overall calving rate to first AI was 57.2%. The corresponding values for heifers, first-lactation, second-lactation, and >second-lactation cows were 64.9, 54.3, 54.7, and 53.9%. The overall difference between NRR60d and pregnancy incidence was 8.8%, whereas the parity-specific differences were 6.9, 8.9, 8.3, and 11.3% for heifers, first-lactation, second-lactation, and >second-lactation cows, respectively. Eight animals with PAG <2.5 ng/mL and classified as pregnant by rectal palpation calved, whereas 5 animals with PAG >or=2.5 ng/mL and classified as non-pregnant by rectal palpation also calved. The study showed that Norwegian Red cows have relatively high reproductive performance. Breeding for fertility traits over 35 yr is probably an important reason for such high fertility. [less ▲]

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See detailPregnancy-associated glycoprotein secretion in North Moroccan goats
Chentouf, M.; El Amiri, B.; Sulon, Joseph ULg et al

in Reproduction in Domestic Animals (2008), 43(6), 696-700

The plasma profile of pregnancy-associated glycoprotein (PAG) and its relationship with fetal number were studied in 14 North Moroccan goats using a semi-heterologous radioimmunoassay (RIA). Peripheral ... [more ▼]

The plasma profile of pregnancy-associated glycoprotein (PAG) and its relationship with fetal number were studied in 14 North Moroccan goats using a semi-heterologous radioimmunoassay (RIA). Peripheral blood was collected every day during the first month of pregnancy, afterward the blood samples were collected trice a week. The PAG were first detected at day 20 of pregnancy, their levels increase to week 8 of gestation then decrease slightly until parturition. Statistical differences between goats carrying one or two foetuses are observed from week 5 of pregnancy until parturition. Factorial Discriminant Analysis provides mathematical models for the discrimination between the litter size using the PAG level and the week of pregnancy. Using only one blood sample per week, high sensitivity, specificity and overall accuracy (74%, 88% and 81%) were obtained using these models. It is concluded that the PAG RIA is an effective tool for early diagnosis of pregnancy and for discrimination between the litter sizes in North Moroccan goats. [less ▲]

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See detailCurrent trends in follow-up of trophoblastic function in ruminant species
Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg; Gajewski, Z.

in Journal of Physiology and Pharmacology : an Official Journal of the Polish Physiological Society (2008), 59 Suppl 9

During the pregnancy of ruminants, different hormones and proteins are secreted by placenta or corpus luteum allowing the follow up of gestation. Among them, progesterone (P4) and pregnancy-associated ... [more ▼]

During the pregnancy of ruminants, different hormones and proteins are secreted by placenta or corpus luteum allowing the follow up of gestation. Among them, progesterone (P4) and pregnancy-associated glycoproteins (PAG) were proposed as laboratory tools to establish or to confirm pregnancy diagnosis. In last years, PAG assay also provided useful information for researchers working in programs focused on the follow up of trophoblastic function. Concentrations of PAG appeared as altered after the use of embryo biotechnology (in vitro fertilization, cloning by nuclear transfer, inter-specific pregnancies), according to nutritional status of pregnant females (overnourished or undernourished), or consecutive to infectious diseases leading to pathologies affecting the pregnancy in cows (Actynomyces pyogenes and Neospora caninum) and goats (Toxoplasma gondii, Listeria monocytogenes and Trypanosoma congolense). As well, in numerous studies, the association of repeated ultrasound examinations with P4 and PAG determinations allowed a better understanding of mechanisms related to embryonic and fetal mortalities: failure after artificial insemination or embryo transfer techniques, large offspring syndrome after in vitro fecundation and cloning. [less ▲]

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See detailMeiotic segregation analysis in cows carrying the t(1;29) Robertsonian translocation.
Bonnet-Garnier, A.; Lacaze, S.; Beckers, Jean-François ULg et al

in Cytogenetic & Genome Research (2008), 120

Heterozygous carriers of Robertsonian translocations generally have a normal phenotype but present reproductive failure. In cattle, the t(1;29) Robertsonian translocation is very common and carriers show ... [more ▼]

Heterozygous carriers of Robertsonian translocations generally have a normal phenotype but present reproductive failure. In cattle, the t(1;29) Robertsonian translocation is very common and carriers show a 3-5% decrease in fertility. Some data suggest that female carriers have a higher decrease than male carriers but no direct studies of the chromosome content of oocytes from a t(1;29) carrier cow have been performed so far. Four heterozygous carrier cows underwent hormonal stimulations and follicles punctions and about 800 oocytes were matured in vitro. Six hundred metaphase II preparations were obtained and analysed by fluorescent in situ hybridization with bovine chromosome 1 and 29 painting probes. Proportions of different kinds of oocytes were assessed: 74.11% (292/394) were normal and balanced, 4.06% (16/394) unbalanced and 21.83% (86/394) diploid. For all cows, the number of normal oocytes was not significantly different from the number of translocated oocytes but the diploidy and unbalanced rate were significantly different between them. As found in bulls, the meiotic segregation pattern in cows has shown a preponderance of alternate products. However, the frequency of unbalanced gametes determined in females (4.06%) was significantly higher than the frequency observed in males (2.76%). The divergence in the rate of diploid gametes (0.04% vs. 21.83%) is mainly explained by the difference between males and females. [less ▲]

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See detailUnknown placental glycoprotein K-76 kDa [Fragment] from Bison bonasus placenta - Access number P85330
Kiewisz, J.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

E-print/Working paper (2008)

N-terminal microsequence obtained after purification and characterization of placental proteins in Bison bonasus. Proteins were submitted to SwissProt databank.

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See detailUnknown placental glycoprotein J2-45 kDa [Fragment] from Bison bonasus placenta - Access number P85329
Kiewisz, J.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

E-print/Working paper (2008)

N-terminal microsequence obtained after purification and characterization of placental proteins in Bison bonasus. Proteins were submitted to SwissProt databank.

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See detailUnknown placental glycoprotein J1-45 kDa [Fragment] from Bison bonasus placenta - P85328
Kiewisz, J.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

E-print/Working paper (2008)

N-terminal microsequence obtained after purification and characterization of placental proteins in Bison bonasus. Proteins were submitted to SwissProt databank.

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See detailPregnancy-Associated Glycoprotein I-50 kDa [Fragment] from Bison bonasus placenta - Access number P85327
Kiewisz, J.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

E-print/Working paper (2008)

N-terminal microsequence obtained after purification and characterization of placental proteins in Bison bonasus. Proteins were submitted to SwissProt databank.

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See detailPregnancy-Associated Glycoprotein H-60 kDa [Fragment] from Bison bonasus placenta - Access number P85326
Kiewisz, J.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

E-print/Working paper (2008)

N-terminal microsequence obtained after purification and characterization of placental proteins in Bison bonasus. Proteins were submitted to SwissProt databank.

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See detailPregnancy-Associated Glycoprotein G-71 kDa [Fragment] from Bison bonasus placenta - Access number P85325
Kiewisz, J.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

E-print/Working paper (2008)

N-terminal microsequence obtained after purification and characterization of placental proteins in Bison bonasus. Proteins were submitted to SwissProt databank.

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See detailPregnancy-Associated Glycoprotein F-50 kDa [Fragment] from Bison bonasus placenta - Access number P85324
Kiewisz, J.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

E-print/Working paper (2008)

N-terminal microsequence obtained after purification and characterization of placental proteins in Bison bonasus. Proteins were submitted to SwissProt databank.

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See detailPregnancy-Associated Glycoprotein E-55 kDa [Fragment] from Bison bonasus placenta - Access number P85323
Kiewisz, J.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

E-print/Working paper (2008)

N-terminal microsequence obtained after purification and characterization of placental proteins in Bison bonasus. Proteins were submitted to SwissProt databank.

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See detailPregnancy-Associated Glycoprotein C-50 kDa [Fragment] from Bison bonasus placenta - Access number P85322
Kiewisz, J.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

E-print/Working paper (2008)

N-terminal microsequence obtained after purification and characterization of placental proteins in Bison bonasus. Proteins were submitted to SwissProt databank.

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See detailPregnancy-Associated Glycoprotein C-50 kDa [Fragment] from Bison bonasus placenta - Access number P85321
Kiewisz, J.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

E-print/Working paper (2008)

N-terminal microsequence obtained after purification and characterization of placental proteins in Bison bonasus. Proteins were submitted to SwissProt databank.

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See detailPregnancy-Associated Glycoprotein B-55 kDa [Fragment] from Bison bonasus placenta - Access number P85320
Kiewisz, J.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

E-print/Working paper (2008)

N-terminal microsequence obtained after purification and characterization of placental proteins in Bison bonasus. Proteins were submitted to SwissProt databank.

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See detailPregnancy-Associated Glycoprotein A-67 kDa [Fragment] from Bison bonasus placenta - Access number P85319
Kiewisz, J.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

E-print/Working paper (2008)

N-terminal microsequence obtained after purification and characterization of placental proteins in Bison bonasus. Proteins were submitted to SwissProt databank.

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See detailIdentification of multiple pregnancy-associated glycoproteins (PAGs) purified from the European bison (Eb; Bison bonasus L.) placentas.
Kiewisz, J.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

in Animal Reproduction Science (2008), 112

This paper describes the first identified chorionic PAGs in the European bison (Eb), named EbPAGs, predominantly expressed during early and mid-pregnancy (45-120 day post-coitum; dpc). Many EbPAGs were ... [more ▼]

This paper describes the first identified chorionic PAGs in the European bison (Eb), named EbPAGs, predominantly expressed during early and mid-pregnancy (45-120 day post-coitum; dpc). Many EbPAGs were extracted from various cotyledonary tissues, precipitated, chromatographed (DEAE and VVA: Vicia villosa agglutinin), electrophoresed (1D- and 2D-PAGE), analysed by heterologous (cross-species) Western blotting and then micro-sequenced by Edman degradation. Finally, twelve selected VVA-purified isoforms (Ip 3.7-7.4) were entirely characterised. Nine identified NH(2)-terminal micro-sequences were found to be PAGs. On 45dpc, three identified forms were named: EbPAG(67AkDa) (RGSNLTHPLRNIGDLFYVGN), EbPAG(55BkDa) (RGSNLTHPL) and EbPAG(50CkDa) (SQISLRGSNLTI). On 60dpc, the next three forms were named: EbPAG(71DkDa) (RGSNLTIHPLRNIIDLFYVG), EbPAG(55EkDa) (RGSNLTHPLRNI) and EbPAG(50FkDa) (SQISLRGS). On 120dpc, three other forms were named: EbPAG(71GkDa) (RGSNLTHPLRNIRDLFYVG), EbPAG(60HkDa) (RGSNLTTHPLRNIKDLVVYM) and EbPAG(50IkDa) (SGSNLTTV). These EbPAG ((A-I)) sequences are unique, as they are not identical to any other PAGs purified previously in related species of the Bovidae family. However, the EbPAGs (A-I forms) have some sequence resemblance to internal sequences of various full-length polypeptide PAG precursors (in silico translated from cloned cDNAs) identified in domestic cattle. Three other novel native isoforms (J1, J2 and K): EbUPG(45kDa) J1 (SKDNYKNYIPLIVPFAT), EbUPG(45kDa) J2 (SKDNQKNYIPLIVPFAT) and EbUPG(76kDa) K (SPEFTV), were temporarily named 'unknown placental glycoproteins' (UPGs), due to their efficient VVA-purification (specific for glycoproteins only) and a lack of considerable consensus to previously sequenced placental glycoproteins in the Bovidae family. This is the first study identifying NH(2)-terminals of multiple/diverse EbPAGs and some EbUPGs purified from the synepitheliochorial cotyledonary placenta of the endangered Bison bonasus (Red list) [less ▲]

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See detailLes glycoproteines placentaires chez les mammiferes
Clerget, E.; Melo de Sousa, Noelita ULg; Bella, Amina ULg et al

in Annales d'Endocrinologie (2008), 69

Placental tissue exhibits a typical glycosylation pattern, which differs from that observed in the pituitary gland. Depending to the species and pregnancy period, the placenta synthesizes diverse ... [more ▼]

Placental tissue exhibits a typical glycosylation pattern, which differs from that observed in the pituitary gland. Depending to the species and pregnancy period, the placenta synthesizes diverse glycoproteins, some of which have significant hormonal activity, others being detected in maternal circulation. Thus, these molecules are of interest both from a fundamental and clinical point of view. Among the mammalian placental glycoproteins currently recognized, chorionic gonadotrophins from primates and Equidae, placental lactogen from bovines and the pregnancy-associated glycoproteins from ruminant species are particularly noteworthy. The diversity of saccharidic structures leads to multiple forms of placental glycoproteins exhibiting distinct structural and biological properties. For instance, concerning the chorionic gonadotrophins, the association of both alpha and beta subunits is essential for the binding of the hormone to specific receptors. Moreover, the N-linked oligossacharides are required for the activation of effectors systems. Bovine placental lactogen is a glycosylated hormone, exhibiting somatotropin- and prolactin-like activities. Several N-glycosylation sites confer to pregnancy-associated glycoproteins a long half-life (8-10 days) in maternal circulation. Assay of these molecules can be used for routine early pregnancy diagnosis and the follow-up of embryonic and fetal mortalities. [less ▲]

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