NM. Sousa

Publications (2)3.09 Total impact

• Article: The glycosylation of pregnancy-associated glycoproteins and prolactin-related protein-I in bovine binucleate trophoblast giant cells changes before parturition.

  K Klisch, A Boos, M Friedrich, K Herzog, M Feldmann, Nm Sousa, Jf Beckers, R Leiser, G Schuler
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  ABSTRACT: Binucleate trophoblast giant cells (BNC) in the bovine placenta produce glycoproteins, which are delivered into the mother after fusion of BNC with uterine epithelial cells. During most time of pregnancy, BNC produce pregnancy-associated glycoproteins (PAGs) and prolactin-related protein-I (PRP-I) with asparagine-linked lactosamine-type glycans terminating with N-acetyl-galactosamine. We show by lectin histochemistry that terminal N-acetyl-galactosamine (detected by Dolichos biflorus agglutinin, DBA) in placentomal BNC is greatly reduced prior to parturition, while lactosamine-type N-glycans (detected by Phaseolus vulgaris leucoagglutinin, PHA-L) remain unaltered. The change in DBA-staining showed no statistically significant differences between placentomes of cows with and without retention of fetal membranes. Western blots revealed that, at parturition the apparent molecular mass of PAGs and PRP-I is 1-2 kDa lower than in late pregnancy. These changes are due to alterations of asparagine-linked glycans, since the molecular weight of the peptide backbones after enzymatical release of asparagine-linked glycans is identical at late pregnancy and parturition. Lectin western blots showed a reduction of terminal N-acetyl-galactosamine on PAGs at parturition. A lectin sandwich-ELISAwas used to differentiate DBA- and PHA-L-binding PAGs in sera of pregnant and non-pregnant cows. The values for DBA-binding PAGs at parturition were not significantly different from non-pregnancy, while the values for PHA-L-binding PAGs were significantly higher at parturition. The peripartal changes of PAG- and PRP-I-glycosylation could alter functional properties of these proteins and might therefore be considered for functional studies. The differentiation of PAG glycoforms in maternal serum could be valuable for a further optimization of PAG-based pregnancy diagnosis in cattle.
  Reproduction (Cambridge, England) 12/2006; 132(5):791-8. · 3.09 Impact Factor
• Article: Application de l'échographie à l'étude de la dynamique folliculaire à l'oestrus induit chez les femelles zébu 'Goudali'

  W. Pitala, H Boly, M. Zongo, I. Coulibaly, NM. Sousa, L. Sawadogo, P. Leroy, JF. Beckers
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  ABSTRACT: Application of Ultrasonography to the Investigation of Follicular Dynamic in Synchronized 'Goudali' Zebu Females. A transrectal ultrasonography was used to follow the follicular dynamics in 8 'Goudali' zebu females. Three treatments were used to synchronize estrus: Group 1: Crestar implant associated to PGF2 and PMSG (n= 4); Group 2: Crestar implant associated to PMSG (n= 2) and Group 3: Crestar implant associated to PGF2 (n= 2). The ultrasonographic examinations were performed as follows: day of implant introduction, day of implant removal, and at 4 hour interval between the 28th and the 56th hour after implant removal. The ovaries were examined 7 days after ovulation to determine the number of corpora lutea. The numbers of 2-3 mm diameter follicles observed at the day of implant removal were 5.8 ± 2.2; 3.5 ± 0.7 et 4.5 ± 0.7, respectively for Groups 1, 2 and 3. At the beginning of estrus (30.4 ± 4.9 hours after implant removal), a mean of 4.1 ± 1.3 follicles with 5-6 mm of diameter has been observed for the 3 groups. At the 36th hour after the end of the synchronization treatment, a mean of 1.1 ± 0.4 dominant follicles (> 8 mm) was observed. The diameter of pre-ovulatory follicles did not vary among groups. The first ovulations have been observed between 22 to 26 hours after the beginning of estrus.
  Tropicultura. 01/2004;