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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 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 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 detailAccuracy of ultrasonography and pregnancy-associated glycoprotein test for pregnancy diagnosis in buffaloes
Karen, A.; Darwish, S.; Ramoun, A. et al

in theriogenology (2007), 68(8), 1150-1155

The aims of the present study were to evaluate and compare the accuracy of transrectal ultrasonography and pregnancy-associated glycoprotein radioimmunoassay (PAG-RIA) test for diagnosis of pregnancy in ... [more ▼]

The aims of the present study were to evaluate and compare the accuracy of transrectal ultrasonography and pregnancy-associated glycoprotein radioimmunoassay (PAG-RIA) test for diagnosis of pregnancy in buffaloes. Two hundred and seventy-five buffalo cows and heifers were examined once for pregnancy diagnosis by transrectal ultrasonography using a 5 MHz linear-array transducer between Days 19 and 55 after mating. After ultrasound scanning, a blood sample was withdrawn from jugular vein of each animal for measuring pregnancy-associated glycoprotein using a heterologous double-antibody RIA. Based on palpation of the uterus per rectum at Days 75-90, 87 animals were designated pregnant and 188 as non-pregnant. The sensitivity of transrectal ultrasonography at Days 19-24 was 44.4%, reaching 100% from Day 31 after mating. The specificity of transrectal ultrasonography ranged between 92.5 and 100% from Days 19 to 55 after mating. The sensitivity of PAG-RIA test was 11.1 % at Days 19-24 and reached 100% from Day 31 after mating. The specificity of PAG-RIA test ranged from 90 to 100% from Days 19 to 55 after mating. There were no significant differences between the sensitivity and specificity of the two tests in all examined periods. In conclusion, transrectal ultrasonography and PAG-RIA test are highly accurate tests for detecting pregnant buffaloes from Day 31 after mating onwards. [less ▲]

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See detailMeasurement of ovine pregnancy-associated glycoprotein (PAG) during early pregnancy in Lacaune sheep
El Amiri, B.; Karen, A.; Sulon, Joseph ULg et al

in Reproduction in Domestic Animals (2007), 42(3), 257-262

This study describes ovine pregnancy-associated glycoprotein (ovPAG) concentrations in 20 Lacaune sheep during early pregnancy. Measurements were performed by using semi-purified ovPAG as standard, tracer ... [more ▼]

This study describes ovine pregnancy-associated glycoprotein (ovPAG) concentrations in 20 Lacaune sheep during early pregnancy. Measurements were performed by using semi-purified ovPAG as standard, tracer and immunogens for antibody production in rabbits. Antisera R780 (against ovPAG(57+59kDa)) and R805 (against ovPAG5(58+61kDa)) were used respectively in RIA-780 and RIA-805. Blood samples were collected at days 0, 18, 20, 22 and 25 after artificial insemination. From day 18 after breeding onward, the mean ovPAG concentration was significantly higher (p < 0.001) in plasma samples from pregnant ewes (n = 17) than in non-pregnant ones (n = 3). The specific activity of the tracer was 11 760 Ci/mmol in RIA-780 and 14 900 Ci/mmol in RIA-805. The minimal detection limits for RIA-780 and RIA-805 were 0.2 ng/ml and 0.3 ng/ml, respectively. The intra-assay CV of samples with low (1.0 ng/ml), medium (2.5 ng/ml) and high (4.0 ng/ml) PAG concentrations were 3%, 6% and 9% for RIA-780 and 8%, 9% and 5% for RIA-805. The inter-assay CV in the same samples were 13%, 12% and 7% for RIA-780 and 13%, 11% and 5% for RIA-805. The recovery was higher than 95% in both assays. No cross-reaction was observed with members of aspartic proteinase family as well as with other tested proteins. In both RIA-780 and RIA-805, inhibition of the binding of the tracer by antisera was parallel between standard curve and serial dilutions of pregnant ewe samples. In conclusion, the two homologous RIA systems are suitable for early quantification of ovPAG concentrations in ewe plasma samples from day 18 after breeding. [less ▲]

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See detailPlasma concentrations of pregnancy-associated glycoprotein-1 (PAG-1) in high producing dairy cows suffering early fetal loss during the warm season
Lopez-Gatius, F.; Hunter, R. H. F.; Garbayo, J. M. et al

in Theriogenology (2007), 67(8), 1324-1330

The present study was designed to establish whether plasma pregnancy-associated glycoprotein-1 (PAG-1) measurements during the early fetal period can be associated with early fetal loss. Blood samples ... [more ▼]

The present study was designed to establish whether plasma pregnancy-associated glycoprotein-1 (PAG-1) measurements during the early fetal period can be associated with early fetal loss. Blood samples were obtained and ultrasound controls performed on days 35, 42, 49, 56, and 63 of gestation or until pregnancy loss from 98 lactating dairy cows. Radioimmunoassay systems were used to determine PAG-1 and progesterone concentrations. Of the 98 pregnancies investigated 18 (18.4%) suffered early fetal loss: 15 (18.5%) in cows carrying singletons, and 3 (16.7%) in twin pregnancies. In cows suffering pregnancy loss, all living embryos registered on day 35 seemed normal in size and development in all weekly ultrasound controls before fetal expulsion. Using analysis of variance, plasma PAG-1 and progesterone values were not different between no loss and fetal loss groups for every gestation period. Based on the odds ratio, and considering only PAG-1 values obtained on day 35 of gestation, the risk of fetal loss was 10 and 6.8 times more likely in cows with low (< 2.5 ng/ml) and high (> 4 ng/ml) PAG-1 values, respectively, than in cows with medium PAG-1 values, used as reference. Of the 10 inseminating bulls included in the study, one was related to increased fetal loss by odds ratio of 21.7, whereas one bull was attributed fetal loss rate reduced by odds ratio of 12.5 (1/0.08) These findings can have a clear clinical application: PAG-1 measurements from one single sample taken on clay 35 of gestation provided more useful information than a series of values obtained from day 35 to 63 of gestation, and can be indicators of subsequent fetal loss. (c) 2007 Elsevier Inc. All rights reserved. [less ▲]

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See detailMilk production correlates negatively with plasma levels of pregnancy-associated glycoprotein (PAG) during the early fetal period in high producing dairy cows with live fetuses
Lopez-Gatius, F.; Garbayo, J. M.; Santolaria, P. et al

in Domestic Animal Endocrinology (2007), 32(1), 29-42

This study was designed to establish possible factors affecting plasma pregnancy-associated glycoprotein (PAG) concentrations during early pregnancy in high producing dairy cows with live fetuses. Blood ... [more ▼]

This study was designed to establish possible factors affecting plasma pregnancy-associated glycoprotein (PAG) concentrations during early pregnancy in high producing dairy cows with live fetuses. Blood samples were obtained on days 35, 42, 49, 56 and 63 of gestation from 80 lactating cows in two herds carrying live fetuses. Radioimmunoassay systems were used to determine PAG (RIA-497 and RIA-706) and progesterone concentrations. We evaluated the effects on PAG concentrations of herd, lactation number, sire of fetus, day of gestation, fetus number, plasma progesterone and milk production at each time point established, along with possible paired interactions. Mean milk production per cow approached 41 kg during the study period. PAG concentrations were not affected by herd, lactation number or plasma progesterone concentration. Significant positive effects on PAG concentrations were shown by the gestation day, and the interaction between day of gestation and twin pregnancy. Significant differences between bulls and a significant negative correlation between milk production and PAG values on day 63 of pregnancy were also detected. Proportions of blood samples showing undetectable PAG levels and false negative diagnoses throughout the study period were significantly higher (P < 0.001) using the RIA-497 system (2.5% and 5.3%, respectively) compared to RIA-706 (0% and 0.8%, respectively). Our findings suggest that PAG concentrations during the early fetal period are related to the day of gestation, milk production, number of fetuses and sire of fetus in high producing dairy cows. Under our working conditions, the RIA-706 method was better at detecting plasma PAG molecules than the RIA-497 system. (c) 2005 Elsevier Inc. All rights reserved. [less ▲]

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See detailRadioimmunoassay of bovine placental lactogen using recombinant and native preparations: determination of fetal concentrations across gestation
Alvarez-Oxiley, A. V.; Melo de Sousa, Noelita ULg; Hornick, Jean-Luc ULg et al

in Reproduction, Fertility and Development (2007), 19(7), 877-885

Concentrations of bovine placental lactogen ( bPL) were determined in fetal plasma samples by twelve double-antibody competitive radioimmunoassay systems ( RIA I - XII) based on either recombinant bPL ... [more ▼]

Concentrations of bovine placental lactogen ( bPL) were determined in fetal plasma samples by twelve double-antibody competitive radioimmunoassay systems ( RIA I - XII) based on either recombinant bPL ( non- glycosylated) or native bPL ( glycosylated). Both preparations were used as standard and tracer, and for primary antisera production. The minimum detection limit measured by these RIA varied from 0.02 to 0.6 ng bPLmL(-1). The coefficients of correlation of different bPL RIA systems were up to 90% ( P< 0.0001) when each RIA was tested against the average values of all twelve RIA systems. All developed RIA were used to investigate the incidence of different bPL isoforms in bovine fetal serum samples ( n= 71). Fetal concentrations ranged from 11.8 to 35.7 ng mL(-1) at the third month and from 1.1 to 13.5 ngmL(-1) at the ninth month of gestation. They tended to decrease with advancing gestation. In general, those RIA systems that used recombinant bPL as the standard measured higher values than those using the native bPL preparation. These differences decreased toward the end of gestation ( P< 0.05), suggesting a lower rate of glycosylation. Our results provide evidence of different glycosylated isoforms of bPL in fetal serum at different gestation periods. [less ▲]

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See detailEstrus synchronization, artificial insemination, and pregnancy diagnosis in water buffaloes (Bubalus bubalis)
Hanh, NV; Huu, QX; Uoc, NT et al

in Reproduction, Fertility and Development (2007), 19(1), 198

One of the big obstacles in management of reproductive activity in water buffaloes is their silent estrus. This characteristic prevents the determination of time for artificial insemination (AI ... [more ▼]

One of the big obstacles in management of reproductive activity in water buffaloes is their silent estrus. This characteristic prevents the determination of time for artificial insemination (AI), resulting in lengthening of the calving interval (Nguyen et al. 1990 Proc. FAO Workshop, Bulgaria, 210–216). Pregnancy-associated glycoprotein (PAG) measurement in maternal blood is an effective method of early pregnancy diagnosis in ruminant species (Zoli et al. 1992 Biol. Reprod. 46, 83–92). The present study describes a preliminary attempt to improve buffalo reproductive performance by association of three different approaches: synchronization of estrus by hormonal treatment, followed by two AI, and finally pregnancy diagnosis based on PAG measurements. A total of 33 buffalo females (4 to 15 years old), with no apparent estrus during a period of 9 to 36 months after last calving, were used. Each female received 2 injections of 5 mL of PGF2α (Intervet, France) 10 days apart (Day -12 and Day -2), one injection of 500 IU of PMSG (SABC, Vietnam) at Day -5, and 1000 IU of hCG (Intervet, France) on the day of AI (Day 0). A second AI was performed 8 h after hCG injection. Blood samples (9 mL) were collected from each female at Days 20, 25, 40, and 45 after AI. Blood samples were withdrawn by jugular venipuncture (heparinized Vacutainer tubes) and kept in a cool box until centrifugation (500g, 10 min). Plasma samples were stored at -20°C until assayed for PAG. Pregnancy diagnosis was considered negative, doubtful, or positive according to the PAG concentrations (<0.6 ng mL-1, 0.6 to 0.8 ng mL-1, and >0.8 ng mL-1, respectively). Clinical observation of females after insemination showed that the total rate of animals that exhibited signs of estrus until Day 45 was 9.1% (3/33). These 3 females were not considered for pregnancy diagnosis. Table 1 shows the results of pregnancy diagnosis in 30 water buffalo females. These results show that fertilization is easily obtained after estrus synchronization in buffaloes and that measurement of PAG concentrations in maternal plasma can be used for pregnancy diagnosis from Day 40 after AI. [less ▲]

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See detailPregnancy-Associated Glycoprotein 62 [Fragment] from Bubalus bubalis placenta - Access number P85050
Barbato, O.; Melo de Sousa, Noelita ULg; Debenedetti, A. et al

E-print/Working paper (2007)

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

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See detailPregnancy-Associated Glycoprotein 70 [Fragment] from Bubalus bubalis placenta - Access number P85049
Barbato, O.; Melo de Sousa, Noelita ULg; Debenedetti, A. et al

E-print/Working paper (2007)

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

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See detailPregnancy-Associated Glycoprotein 75 [Fragment] from Bubalus bubalis placenta - Access number P85048
Barbato, O.; Melo de Sousa, Noelita ULg; Debenedetti, A. et al

E-print/Working paper (2007)

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

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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 detailRelationship between progesterone and pregnancy-associated glycoprotein concentrations in the maternal circulation during early pregnancy in dairy cows.
Barbato, O.; Merlo, M.; Melo de Sousa, Noelita ULg et al

in Proceedings of the 23rd Scientific Meeting of the European Embryo Transfer Association (2007)

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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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See detailPlasma pregnancy-associated glycoprotein-1 (PAG-1) concentrations during gestation in Neospora-infected dairy cows.
Lopez-Gatius, F.; Garbayo, J. M.; Santolaria, P. et al

in Theriogenology (2007), 67(3), 502-8

The aim of this study was to determine whether plasma pregnancy-associated glycoprotein-1 (PAG-1) concentrations in pregnancy are affected by persistent Neospora caninum infection in dairy cows. The data ... [more ▼]

The aim of this study was to determine whether plasma pregnancy-associated glycoprotein-1 (PAG-1) concentrations in pregnancy are affected by persistent Neospora caninum infection in dairy cows. The data analyzed were derived from 22 multiparous cows: 16 N. caninum-seropositive and 6 N. caninum-seronegative animals (used as controls). Three of the 16 seropositive cows aborted during the study period and the corresponding data were analyzed separately. Pregnancy diagnoses were performed on day 40 post-insemination by transrectal ultrasound, and by palpation per rectum on days 90, 120, 150, 180 and 210. Blood samples were collected from each animal immediately before each pregnancy diagnosis, and then at parturition or at the time of abortion detection. Plasma was tested for antibodies against N. caninum and PAG-1 concentrations were determined by radioimmunoassay. In non-aborting animals, the effects of neosporosis (seropositive versus seronegative), N. caninum antibody levels, semen providing bull, sex of the newborn, and day of gestation on PAG-1 concentrations were evaluated by GLM repeated measures analysis of variance. The effect of the gestation period (first half versus second half) on the N. caninum antibody titer was established by the Student's t-test in seropositive cows. A significant positive effect of gestation day on PAG-1 concentrations was observed (d.f.=6; F=12.6; P<0.0001). For all cows, PAG-1 concentrations increased steadily during the course of gestation, with peak concentrations recorded at parturition. Neosporosis (P=0.493), N. caninum antibody levels (P=0.921), sex of the newborn (P=0.856) and semen providing bull (P=0.087) had no effect on plasma PAG-1 concentration. There was a significant 52% increase (P<0.0001) in N. caninum antibody titers during the second half of gestation compared to the first half. The fates of the three aborting cows were abortion on gestation day 215 in one, and fetus mummification diagnosed on gestation days 180 and 210, respectively, in the remaining two cows. A luteolytic dose of prostaglandin was applied 30 days after mummification diagnosis in these last two cows, and fetus expulsion was detected on days 215 and 250, respectively. Two of the aborted fetuses were submitted to laboratory analysis and the presence of N. caninum was confirmed by specific PCR. In the cows with a mummified fetus, PAG-1 concentrations were low or undetectable when the diagnosis was made. These findings suggest that N. caninum infection has no effect on placental function in chronically infected, cows not suffering abortion, while PAG-1 measurements in aborting animals provide a useful indication of feto-placental status. [less ▲]

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See detailProtection against abortion linked to gamma interferon production in pregnant dairy cows naturally infected with Neospora caninum
Lopez-Gatius, F.; Almeria, S.; Donofrio, G. et al

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 ▲]

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See detailInfluence of progesterone concentrations on secretory functions of trophoblast and pituitary during the first trimester of pregnancy in dairy cattle
Ayad, A.; Melo de Sousa, Noelita ULg; Sulon, Joseph ULg et al

in Theriogenology (2007), 67(9), 1503-1511

The essential role played by progesterone in the maintenance of pregnancy is unequivocal; however, the effects of progesterone on the secretory patterns of placental and pituitary molecules during the ... [more ▼]

The essential role played by progesterone in the maintenance of pregnancy is unequivocal; however, the effects of progesterone on the secretory patterns of placental and pituitary molecules during the gestation period are not well defined. The objective of this study was to describe pregnancy-associated glycoprotein (PAG) concentrations (measured by RIA-497 and RIA-Pool) in pregnant females with progesterone concentrations lower (low-P4 group, n = 20) or higher (high-P4 group, n = 17) than the mean of 8.74 ng/mL on Day 21 (AI = Day 0). Luteinizing hormone (LH) and prolactin concentrations were also measured in both groups. Throughout the study period, blood samples were collected on Days 0, 21, 45, 60, and 80 from 37 females that were confirmed to be pregnant. PAG concentrations measured by both RIA-497 and RIA-Pool tended to be higher in high-P4 group than in low-P4 group from Day 30 until Day 80. On Day 80, plasma PAG concentrations that were measured using RIA-497 were observed to be higher (P < 0.05) in the high-P4 group than in the low-P4 group (10.2 +/- 8.7 ng/mL versus 6.9 +/- 13.8 ng/mL). Concentrations of LH on Day 60 and prolactin on Day 80 were observed to be significantly lower (P < 0.05) in the high-P4 group. There was a tendency for the concentrations of LH (Days 45 and 80) and prolactin (Days 30, 45, and 60) to be lower in cows in the high-P4 group than in the low-P4 group. Our results suggest the existence of a relationship among the concentration levels of progesterone, PAG, LH, and prolactin during early pregnancy. (C) 2007 Elsevier Inc. All rights reserved. [less ▲]

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See detailComparison of five radioimmunoassay systems for PAG measurement: Ability to detect early pregnancy in cows
Ayad, A.; Melo de Sousa, Noelita ULg; Sulon, Joseph ULg et al

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 ▲]

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