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See detailPlacental and gastric aspartic proteinases: new insights from bovine species
Bella, Amina ULg; Beckers, Jean-François ULg; Melo de Sousa, Noelita ULg

in Proceedings of the 2nd Scientific Meeting of the Faculty of Veterinary Medicine (2012, October 19)

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See detailPregnancy-associated glycoprotein, chymosin and pepsinogen immunoreactivity of proteins extracted from fetal gastric tissue in bovine species.
Bella, Amina ULg; Melo de Sousa, Noelita ULg; Dehimi, M. L. et al

in Research in Veterinary Science (2012), 92(3), 378-386

The objective of this work was to investigate the expression of gastric aspartic proteinases in fundic and pyloric mucosa removed from bovine fetuses. For this purpose, fractions issued from classical ... [more ▼]

The objective of this work was to investigate the expression of gastric aspartic proteinases in fundic and pyloric mucosa removed from bovine fetuses. For this purpose, fractions issued from classical biochemical protocols were analyzed by proteolytic method, by PAG-RIA and by Western blot with the use of antisera raised against both pepsinogens and PAG. A strong reaction of proteins extracted from the fundic mucosa collected at the beginning of pregnancy was revealed with both anti-bPAG-I and anti-bPAG-II antisera, suggesting the expression of pepsinogen F in bovine species. Concerning pyloric mucosa, the analysis by Western blot highlighted a very strong immunoreaction with the anti-bovine chymosin serum. Amino-terminal sequencing allowed to identify bovine fetuin and albumin in fundic extracts, chymosin in the pyloric mucosa extracts, as well as some unknown proteins in both mucosa. Despite no N-terminal microsequence corresponding to the hypothetical pepsinogen F could be identified, it cannot be excluded that an existing bovine pepsinogen F-like molecule could be degraded during the purification procedure or that co-purified proteins could be responsible for masking its N-terminal microsequence. [less ▲]

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See detailDevelopment of a new radioimmunoassay by using antiserum against pregnancy-associated glycoprotein II : concentrations in holstein dairy cattle .
Bella, Amina ULg; Melo de Sousa, Noelita ULg; Lopez-Gatius, F. et al

in Proceedings of the 6th European Congress of Bovine Health and Management (ECBHM) (2011, September 07)

Bovine pregnancy-associated glycoproteins (boPAG) can be classified into two main subfamilies: the boPAG–1 and the boPAG–2 groups. RIA systems allow quantifying boPAG-1 molecules in pregnant cattle ... [more ▼]

Bovine pregnancy-associated glycoproteins (boPAG) can be classified into two main subfamilies: the boPAG–1 and the boPAG–2 groups. RIA systems allow quantifying boPAG-1 molecules in pregnant cattle. Concerning boPAG-2, as no radioimmunoassay was developed, its quantification in peripheral blood of pregnant cows remains to be investigated. The present work aimed to develop a new heterologous RIA allowing the measurement of boPAG-2 concentrations in bovine species. A total of 77 Holstein dairy cows were used for this study. They were bled at Days 45, 90, 120, 150, 180, 210 after AI, at parturition and at Day 30 postpartum. Polyclonal antiserum against boPAG-2 (AS438) was raised in New Zealand rabbits. Due to the instability of boPAG-2 molecule, we used boPAG-1 (67 kDa) as standard (dilutions ranging from 100 to 0.8 ng/mL) and for iodination with 125-I isotope. The optimal dilution for primary AS438 was 1:1,1500. Mean concentrations of boPAG-2 increased continuously from Day 45 of pregnancy (0.78 ± 0.07 ng/mL) reaching a peak at Day 210 (32.78 ± 3.02 ng/mL). Thereafter, they decreased until parturition (7.73 ± 0.59). Lower PAG concentrations were observed at Day 30 postpartum (3.62 ± 0.31 ng/mL). In conclusion, boPAG-2 profile differed from boPAG-1. In general, concentrations of boPAG-2 reached lower values, with no dramatic increase being observed at peripartum period. Due to the lower postpartum concentrations, it is expected that this new RIA can be available for pregnancy diagnosis of cows inseminated in early postpartum, minimizing the risk of false positive concentrations due to the previous pregnancy. [less ▲]

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See detailConcentrations of pepsinogens A and C in peripheral blood of cattle at different developmental stages.
Melo de Sousa, Noelita ULg; Michiels, Jean-Albert ULg; Terroni, D. et al

in Proceedings of the 6th European Congress of Bovine Health and Management (ECBHM) (2011, September 07)

Measurements of global proteolytic activity of pepsinogens are successfully used for diagnosis of gastric nematode parasitism in cattle. Higher pepsinogen concentrations detected in peripheral circulation ... [more ▼]

Measurements of global proteolytic activity of pepsinogens are successfully used for diagnosis of gastric nematode parasitism in cattle. Higher pepsinogen concentrations detected in peripheral circulation were found to be associated with damage in gastric mucosa The aim of the present study was to investigate the ontogenesis of PgnA and PgnC in cattle. Bovine PgnA and PgnC were isolated in our laboratory. Both antigens were labeled to 125I by using chloramine T method. Standard curves ranged from 125 to 1.0 ng/mL. Antisera were raised in rabbits: AS866 (anti-PgnA) and AS869 (anti-PgnC). The optimal dilutions for primary antisera were 1:15,000 and 1:20,000 for AS866 and AS869, respectively. In order to establish the ontogenesis of both PgnA and PgnC, samples were collected from 50 bovine fetuses (3rd to the 9th month), 18 calves and 57 adult cattle. Mean(±SEM) concentrations of PgnA were 4.6±0.7 ng/mL, 78.9±6.7 ng/mL and 133.2±17.6 ng/mL in fetuses, calves and mature cows, respectively. Concentrations of PgnC were <0.9 ng/mL, 13.5±1.1 ng/ml and 201.5±26.5 ng/ml in fetuses, calves and mature cows, respectively. The ratio PgnA/PgnC concentrations decrease from fetal age (maximal ratio due to undetectable PgnC concentrations), being 5.8 in young calves and lowest (0.7) in mature cows. In conclusion, PgnA and PgnC concentrations can be distinctly measured by specific RIA systems. Ratio PgnA/PgnC concentrations can be useful to better understand the ontogenesis of gastric aspartic proteinases in cattle. It is expected that clinical application of these assays will help vet practitioners to establish diagnosis of gastric nematode parasitism in dairy and beef herds taking into account the age of the animal. [less ▲]

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See detailPregnancy diagnosis in cattle by using a new ELISA for pregnancy-associated glycoprotein: preliminary results.
Beckers, Jean-François ULg; Melo de Sousa, Noelita ULg; Colemonts, Y. et al

in Proceedings of the 6th European Congress of Bovine Health and Management (ECBHM) (2011, September 07)

In the present study we report the use of a new PAG-ELISA for routine pregnancy diagnosis in cattle. A total of 2777 samples were collected from pregnant or non-pregnant cows and assayed by both classical ... [more ▼]

In the present study we report the use of a new PAG-ELISA for routine pregnancy diagnosis in cattle. A total of 2777 samples were collected from pregnant or non-pregnant cows and assayed by both classical PAG RIA-497 method and newly developed PAG-ELISA (Ref. code E.G.7, CER, Maloie). Pregnancy status was determined on the basis of RIA results. Samples were assumed to be issued from pregnant cows when PAG concentrations were higher than 0.8 ng/mL. PAG concentrations <0.8 ng/mL were considered negative (non-pregnant). PAG concentrations between 0.8 and 1.0 ng/mL were considered doubtful. With regard to ELISA, concentrations below 0.6 were considered negative. Concentrations between 0.6 and 0.8 ng/mL were considered doubtful and finally concentrations under 0.8 ng/mL were assumed as positive. Sensitivity(Se), specificity(Sp) and predictive values (PV) of pregnancy diagnosis were determined. A total of 143(5.2%), 137(4.9%) and 38(1.4%) samples gave doubtful results by RIA, ELISA or both systems, respectively. These samples (318/2777=11.5%) were not used for estimation of Se, Sp, PPV and NPV because clinical confirmation of pregnancy diagnosis could not be established by an additional method (rectal palpation, ultrasound or calving). Taking into account the remaining samples (2459), Se, Sp, PPV and NPV obtained by ELISA were respectively 98.9%, 89.9%, 98.7% and 96.4%. In conclusion, PAG-ELISA can be successfully used for pregnancy diagnosis in cattle. In the near future, further investigations are to be conducted in order to compare results obtained by ELISA test with those obtained by rectal palpation and ultrasound in field conditions. [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 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 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 detailMonitoring certain endocrine parameters for predicting stillbirth in dairy cows
Szenci, Otto; Bajcsy, A Cs; Brydl, E. et al

in Proceedings: XVII International congress of mediterranean federation of health and production of ruminants (2009)

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See detailEffect of different treatment protocols on ovulation and pregnancy rate in dairy cattle.
Repasy, A.; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg et al

in Magyar Allatorvosok Lapja = Hungarian Veterinary Journal (2008), (Suppl II), 314

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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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See detailPregnancy-associated glycoprotein (PAG) concentrations during the post partum period in four non-pregnant cows.
Ayad, A.; Melo de Sousa, Noelita ULg; Bella, Amina ULg et al

in Proceedings of the The Life Science Summit (2007)

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See detailThe Pregnancy-Associated Glycoproteins: Biochemical Aspects and Clinical Application for Pregnancy Follow-up
Melo de Sousa, Noelita ULg; Barbato, O.; Bella, Amina ULg et al

Conference (2007)

Pregnancy diagnosis is an important part in reproduction management of ruminants. In the last years, a large polymorphic family of placenta-expressed proteins has been discovered in ruminant species and ... [more ▼]

Pregnancy diagnosis is an important part in reproduction management of ruminants. In the last years, a large polymorphic family of placenta-expressed proteins has been discovered in ruminant species and used for pregnancy diagnosis. Members of this family are named pregnancy-associated glycoproteins (PAG), being synthesized in the mono- and binucleate cells of the ruminant’s trophectoderm. Part of them are released in the maternal blood circulation where they can be assayed by different laboratory techniques. Due to large variety of expressed molecules and to large variations in the post-translational processing of the PAG, different immuno-systems present different ability to quantify the PAG released in blood. The sensitivity (92 to 100%) and specificity of PAG radioimmunoassay when used for pregnancy diagnosis are very high. The assay of PAG can also bring very interesting information for researchers working in programs focused on the study of embryonic and fetal mortalities, as well as on embryo biotechnology (ET, FIV, clonage), animal nutrition, or infections diseases resulting in pathologies affecting the pregnancy. [less ▲]

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See detailWestern analyses of pregnancy-associated glycoprotein family (PAG) in placental extracts of various mammals
Bella, Amina ULg; Melo de Sousa, Noelita ULg; Dehimi, M. L. et al

in theriogenology (2007), 68(7), 1055-1066

The present study was conducted in order to analyze the inummoreactivity, of placental extracts of several animal species and humans against the following three groups of PAG antisera: anti-boPAG-1 (R#497 ... [more ▼]

The present study was conducted in order to analyze the inummoreactivity, of placental extracts of several animal species and humans against the following three groups of PAG antisera: anti-boPAG-1 (R#497), -boPAG-II (R#435), and -caPAG (R#706). Placental proteins were obtained after extraction at neutral pH, followed by ammonium sulfate (A.S.) precipitation, dialysis, and lyophilization. The immunoreactivity of different placental extracts was revealed by the use of monodimensional SDS-PAGE, followed by blotting on nitrocellulose membrane and the identification of immunoreactive proteins after incubation with PAG antisera (Western blot technique). A strong immunoreactivity of proteins from synepitheliochorial placenta (cattle, sheep, goat, bison, buffalo, and deer) was demonstrated in both 20-50% and 50-80% A.S. fractions using the three antisera. Proteins from species with epitheliochorial placenta presented variable profiles of detected PAG-like proteins: in the sow, many inummoreactive forms were revealed by antisera boPAG-I and boPAG-II, whereas in the dromedary, only two forms were revealed by anti-boPAG-II. Concerning other species, our protocols showed for the first time a cross-reaction between PAG antisera with proteins extracted from dog, alpaca, dromedary, sea lion, and human placenta. (C) 2007 Elsevier Inc. All rights reserved. [less ▲]

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