Protection against abortion linked to gamma interferon production in pregnant dairy cows naturally infected with Neospora caninum

in Theriogenology (2007), 68(7), 1067-1073

Many immunological aspects of pregnancy, such as the role played by gamma interferon (IFN-gamma) in abortion, are not well understood. Neospora caninum is an intracellular protozoan considered to be among ... [more ▼]

Many immunological aspects of pregnancy, such as the role played by gamma interferon (IFN-gamma) in abortion, are not well understood. Neospora caninum is an intracellular protozoan considered to be among the main causes of abortion in cattle worldwide. The present study analyzes the interaction between IFN-gamma production and N. caninum infection in naturally infected pregnant cows. Data were obtained from 126 pregnant cows: 86 seropositive and 40 seronegative for the parasite. Pregnancy diagnosis and blood sample collection were performed on days 40, 90, 120, 150, 180 and 210 post-insemination or until the time of abortion detection. Plasma was tested for antibodies against N. caninum and IFN-gamma. Interferon-garmna was detected at some point along the pregnancy in 16 (19%) of the 86 Neospora-seropositive cows yet was undetectable in the 40 seronegative animals. Of the 126 pregnancies examined, 22 (17.5%) ended in abortion. Abortion occurred in 24.4% of seropositive cows (21/86) and in 2.5% of seronegative animals (1/40). Significant (P < 0.0001) interaction was observed between Neospora-seropositivity and IFN-gamma production. Based on the odds ratio, the risk of abortion was 15.6 times higher in seropositive cows not producing IFN-gamma than in seronegative animals, whereas neosporosis had no effect in seropositive cows with IFN-gamma production. A significant (P = 0.001) negative effect of IFN-gamma production on the Neospora titer was furthermore observed in the 65 non-aborting seropositive animals. These results indicate that IFN-gamma production affords protection against abortion in Neospora-infected cows and also point to a reduced humoral immune response to N. caninum during gestation in cows producing IFN-gamma. [less ▲]

Comparison of five radioimmunoassay systems for PAG measurement: Ability to detect early pregnancy in cows

in Reproduction in Domestic Animals (2007), 42(4), 433-440

This study was conducted to describe the minimum detection limit, reproducibility, accuracy, specificity and parallelism of different pregnancy-associated glycoprotein radioimmunoassay (PAG-RIA) systems ... [more ▼]

This study was conducted to describe the minimum detection limit, reproducibility, accuracy, specificity and parallelism of different pregnancy-associated glycoprotein radioimmunoassay (PAG-RIA) systems: RIA-497, RIA-706, RIA-780, RIA-809 and RIA-Pool. Their ability to distinguish between non-pregnant and pregnant females at day 30 after artificial insemination (Al) was investigated. The antisera were raised in rabbits against different PAG preparations. All RIA systems proved to be sensitive, repeatable and accurate for measuring PAG concentrations. The dilutions of plasma samples taken at an early stage of pregnancy were found to be parallel to the standard curves. No cross-reaction was observed with different carbohydrates, either with Pregnant Marc Serum Gonadotropin (PMSG) or human Chorionic Gonadotropin (hCG). The concentrations of PAG in pregnant females at day 30 after Al were shown to be higher with the use of antisera R#706, R#780, R#809 and Pool when compared with antiserum R#497. All the RIA systems gave 100% sensitivity and negative predictive values. On the other hand, the use of antisera R#780 and R#809 resulted in lower specificity and positive predictive values. The present study clearly shows that the ability of PAG-RIA systems to diagnose pregnancy specifically at day 30 after Al can be improved by using a combination of antisera raised against different forms of PAG. [less ▲]

The pregnancy-associated glycoproteins expressed in epitheliochorial placenta: new investigations by Western blot technique

in Proceedings of the 10e Journée de Rencontre Bioforum (2006)

Pregnancy-Associated Glycoprotein 76 [Fragment] from Bison bison placenta - Access number P84918

E-print/Working paper (2006)

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

Pregnancy-Associated Glycoprotein 72 [Fragment] from Bison bison placenta - Access number P84916

E-print/Working paper (2006)

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

Progesterone, luteinizing hormone, prolactin and pregnancy-associated glycoproteins during the first trimester pregnancy in cattle.

in Proceedings of the 22nd Scientific Meeting of the European Embryo Transfer Association (2006)

From lectin-histochemistry to pregnancy diagnosis by lectin-ELISA: applications of lectins for the characterisation of bovine pregnancy-associated glycoprotein.

in Proceedings of the XXVIth Congress of the European Association of Veterinary Anatomists (2006)

Isolation of PAG from buffalo (Bubalus bubalis) placenta

in Reproduction (Cambridge, England). Abstract Series (2006), Suppl

Suivi de la gestation chez la brebis Ouled Djellal par dosage de la protéine associée a la gestation et de la progestérone.

in Revue d'Elévage et de Médecine Vétérinaire des Pays Tropicaux (2006), 59(1-4), 65-73

L’objectif de la présente étude a été la caractérisation des profils plasmatiques de la protéine associée à la gestation (PAG) et de la progestérone au cours de la gestation et deux semaines après le part ... [more ▼]

L’objectif de la présente étude a été la caractérisation des profils plasmatiques de la protéine associée à la gestation (PAG) et de la progestérone au cours de la gestation et deux semaines après le part chez la race Ouled Djellal. Vingt-cinq brebis ont été prélevées hebdomadairement après synchronisation des chaleurs et monte naturelle. Les concentrations de PAG et de progestérone ont été déterminées par dosage radio-immunologique. Deux femelles n’ont pas été fécondées tandis que 23 ont eu des gestations considérées comme normales (n=18) ou pathologiques (n=5). Chez 18 brebis (12 gestations simples et 6 multiples), les concentrations de PAG et de progestérone ont été significativement influencées par le stade de la gestation (P<0.0001) et non par le nombre de fœtus. Des profils individuels ont été décrits chez 7 brebis dont 3 femelles ayant eu des pertes embryonnaires, et 2 brebis ayant avorté (66e et 110e jours), et enfin chez 2 brebis ayant donné naissance à terme chacune à un agneau vivant et expulsé au moment de la mise-bas 1 ou 2 fœtus momifié(s). Les concentrations en PAG ont été plus faibles chez les femelles ayant de fœtus momifiés en parallèle avec des fœtus vivants. [less ▲]

Cannulation of bovine fetuses for a long period blood collection: the chirurgical approach

in Proceedings: 24th World Buiatrics Congress (2006)