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See detailFactors Affecting Plasma Pregnancy-associated Glycoprotein 1 Concentrations Throughout Gestation in High-producing Dairy Cows.
Serrano, B.; Lopez-Gatius, F.; Santolaria, P. et al

in Reproduction in Domestic Animals (2009), 44(4), 600-605

This study was designed to establish the factors, if any, which could affect plasma pregnancy-associated glycoprotein-1 (PAG-1) expression in a study population of 87 pregnant, high-producing dairy cows ... [more ▼]

This study was designed to establish the factors, if any, which could affect plasma pregnancy-associated glycoprotein-1 (PAG-1) expression in a study population of 87 pregnant, high-producing dairy cows. The factors examined were: semen providing breed (Holstein-Friesian vs Limousin), outcome of gestation (male vs female newborn, and singleton vs twin pregnancies), lactation number, milk production at pregnancy diagnosis, plasma progesterone concentration, season of gestation (warm period, March-November vs cool period, December-February), and day of gestation (40, 90, 120, 150, 180 and 210). Pregnancy was diagnosed by transrectal ultrasound on day 40 post-insemination 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. The relative contributions of the different factors on PAG-1 concentrations were evaluated by GLM repeated measures analysis of variance. No significant effects of the herd, foetal sex, milk production, lactation number and plasma progesterone concentrations were observed. In contrast, twin pregnancy, the use of Limousin semen and conception during the cool period were correlated with significantly increased plasma PAG-1 concentrations throughout gestation. Our data indicate that both cow well-being during early placental development, determined in our conditions by reduced heat stress when conception occurred in the cool season, and crossbreed pregnancies lead to improved PAG-1 production throughout the gestation period. [less ▲]

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See detailFactors affecting plasma prolactin concentrations throughout gestation in high producing dairy cows.
Garcia-Ispierto, I.; Lopez-Gatius, F.; Almeria, S. et al

in Domestic Animal Endocrinology (2009), 36(2), 57-66

The aim of the present study was to investigate possible relationships between plasma concentrations of prolactin and the following factors throughout gestation in lactating dairy cows: photoperiod ... [more ▼]

The aim of the present study was to investigate possible relationships between plasma concentrations of prolactin and the following factors throughout gestation in lactating dairy cows: photoperiod, season, milk production, Neospora caninum-seropositivity, twin pregnancy, and plasma concentrations of pregnancy associated glycoproteins-1 (PAG-1), progesterone and cortisol. Pregnancy was diagnosed by trans-rectal ultrasonography on Day 40 post-insemination and by palpation per rectum on Days 90, 120, 150, 180 and 210 or until abortion in aborting cows. Blood samples were collected from each animal immediately before each pregnancy diagnosis. The study population was comprised of 73 non-aborting (54 Neospora-seropositive cows) and 20 aborting cows (all Neospora-seropositive) cows. In non-aborting cows, GLM repeated measures of analysis of variance revealed that lactation number and days in milk had no effect on plasma prolactin concentrations throughout gestation, whereas high plasma prolactin concentrations were significantly associated with high plasma levels of cortisol and PAG-1, with Neospora-seropositivity, positive photoperiod (increasing day length), twin pregnancy, and with low plasma progesterone concentrations. An interaction among plasma prolactin, plasma cortisol and milk production was observed in that plasma prolactin concentrations differed significantly throughout gestation and were highest in high-producing cows with high cortisol levels. In Neospora-seropositive non-aborting versus aborting cows, mean prolactin concentrations failed to differ on Days 40, 90, 120, 150 and 180 of pregnancy, whereas prolactin values were significantly lower (P=0.03) in aborting animals on Day 210 of pregnancy. Our results indicate that a positive photoperiod and Neospora-infection lead to increased plasma prolactin concentrations throughout gestation. Reduced prolactin concentrations detected in Neospora-seropositive aborting cows compared to non-aborting animals suggests a protective effect of prolactin in N. caninum infection. [less ▲]

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See detailCorrelation of five radioimmunoassay systems for measurement of bovine plasma pregnancy-associated glycoprotein concentrations at early pregnancy period.
Ayad, A.; Melo de Sousa, Noelita ULg; Sulon, Joseph ULg et al

in Research in Veterinary Science (2009), 86

The measurement of serum or plasma PAG concentrations is currently used as a specific method for pregnancy diagnosis in cattle. In this study, the correlation between five radioimmunoassay systems (RIA ... [more ▼]

The measurement of serum or plasma PAG concentrations is currently used as a specific method for pregnancy diagnosis in cattle. In this study, the correlation between five radioimmunoassay systems (RIA-497, RIA-706, RIA-780, RIA-809 and RIA-Pool) developed for measurement of PAG concentrations in ruminant species was investigated in plasma from pregnant Friesian Holstein females. Plasma PAG concentrations (ng/mL) measured by different RIA systems were significantly correlated between them ( 0.81; P<0.001). PAG concentrations increased significantly from Day 21 (n=27) to 30 (n=37) after AI by use of all PAG-RIA systems. From Day 30 to 80 after AI, lower PAG concentrations were observed when using the homologous system RIA-497. The addition of several proteinase inhibitors changed neither the non specific binding nor the B(0) binding to the tracer. Our results suggest that all tested PAG-RIA (RIA-497, RIA-706, RIA-780, RIA-809 and RIA-Pool) are highly correlated and can be useful to follow PAG concentrations in samples collected during the first trimester of gestation. [less ▲]

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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 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 detailDevelopment and validation of a radioimmunoassay for thyrotropin in cattle
Guyot, Hugues ULg; Sulon, Joseph ULg; Beckers, Jean-François ULg et al

in Journal of Veterinary Diagnostic Investigation (2007), 19(6), 643-651

In mammals, thyrotropin, or thyroid-stimulating hormone (TSH), assay is used for the diagnosis of primary hypothyroidism. Hypothyroidism is the most common type of thyroid disorder in cattle. The aim of ... [more ▼]

In mammals, thyrotropin, or thyroid-stimulating hormone (TSH), assay is used for the diagnosis of primary hypothyroidism. Hypothyroidism is the most common type of thyroid disorder in cattle. The aim of this study was to develop and validate, under physiologic and pathologic conditions, a radioimmunoassay (RIA) for bovine TSH (bTSH). Double RIA was performed with purified bTSH and specific bovine antiserum. Laboratory validation included research of minimal detection limit, accuracy, and reproducibility. The physiologic validation included a thyrotropin-releasing hormone (TRH) challenge performed on euthyroid cows and a follow-up of bTSH concentration over a 24-hour period. Furthermore, bTSH concentration was assayed in a large population of healthy dairy and beef cows to define reference interval. The pathologic validation was made by assaying bTSH and thyroid hormones on healthy and goitrous newborn calves. The minimum detection limit (MDL) for bTSH assay was 1.3 microU/ml. The recovery was 101% to 106%. The intra- and interassay coefficients of variation (CVs) ranged from 5% to 11% and 11% to 15%, respectively. The RIA covered the whole range of physiologic bTSH values, as shown by bTSH values induced by TRH-challenge. A pulsatile secretion of bTSH was observed, accompanied by a diurnal variation with lower night values than day values. Reference intervals of bTSH ranged from 1.3 to 13.0 microU/ml for beef and dairy breeds. Finally, bTSH easily discriminated goitrous newborn calves from healthy ones, leading to the definition of a cutoff value of 35 microU/ml. The bTSH assay positively reacted to physiologic and pathologic conditions. The accuracy and precision of the RIA were satisfying. [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 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 detailThyrotropin in newborn calves as a tool for diagnosing hypothyroidism
Guyot, Hugues ULg; Lebreton, Pascal; Alves de Oliveira, Laurent et al

in Cattle Practice (2007), 15(Part 3), 271-275

The hypothalamic-pituitary-thyroid axis is of particular importance for the adaptation of mammals to their environment. Hypothyroidism is the most common type of thyroid disorders in cattle. Thyrotropin ... [more ▼]

The hypothalamic-pituitary-thyroid axis is of particular importance for the adaptation of mammals to their environment. Hypothyroidism is the most common type of thyroid disorders in cattle. Thyrotropin (TSH) is used in several mammalian species for the diagnosis of primary hypothyroidism. Currently in cattle, thyroid hormone assays are used to diagnose such disease. The aim of the study was to compare different tools for diagnosing hypothyroidism in newborn calves. Twelve goitrous newborn calves from two beef herds were studied as well as 45 healthy newborn calves. Bovine TSH, thyroxine (T4), tri-iodothyronine (T3), reverse-T3 (rT3), plasmatic inorganic iodine (PII) and glutathione peroxidase in erythrocytes (GPXe) were assayed in these calves during the first day of life. T4/T3 and T4/TSH ratio were calculated. Furthermore, TSH, T4, PII and GPXe were also assayed in their dams at calving. Results were analysed using Wilcoxon rank sum test and Spearman's rank correlation coefficient. A significant higher value (P < 0.01) of TSH was seen for the group of goitrous calves compared to healthy calves. There was no difference between healthy and goitrous calves for GPXe (P > 0.1) and PII (P > 0.05). Significantly higher values were seen for healthy calves compared to goitrous calves concerning T4, T4/T3 ratio, T4/TSH ratio, rT3 (P < 0.0 1) and T3 (P < 0.05). Regarding the group of goitrous calves, those that had larger goitre at palpation and were hairless (n=8) died within the first day of life while the four other with moderate goitre and normal hair stayed alive. Goitrous-dead calves had higher TSH values than goitrous-alive ones (P < 0.01), lower T4, T3, T4/TSH (P < 0.0 1) and rT3 (P < 0.05) but similar T4/T3 ratio (P > 0.1). Furthermore, it appeared that T4 and rT3 values in goitrous-alive calves were not different compared to healthy calves (P > 0.1). Regarding TSH (rho=0.44), T4 (rho=-0.44), PII (rho=0.70) and GPXe (rho=0.87), there was a correlation between healthy calves and their dams, with significantly higher values being found in the calves (P < 0.01). There was no correlation between values of TSH and T4 in goitrous calves and their dams (P > 0.1). However, for these animals there was a strong relationship in the values of PH (rho=0.82) and GPXe (rho=0.94) (P < 0.01). TSH, PII and GPXe were significantly higher in goitrous calves compared to their dams (P < 0.01). Regarding T4, only goitrous-dead calves showed significantly lower values than their dams (P < 0.01). Dams with goitrous calves had higher TSH (P < 0.01) and PII (P < 0.05) compared to dams with healthy calves but similar T4 and GPXe (P > 0.1). This study revealed that TSH alone is a good marker for hypothyroidism in newborn calves. In the absence of TSH assay, the T4/T3 ratio may be used to diagnose hypothyroidism in newborn calves. In our study, although T4/T3 ratio was helpful in identifying goitrous calves, it did not allow to discriminate goitrous-dead from goitrous-alive calves, contrary to TSH. In our study, the presence of a goitre in newborn calves could not be explained by the iodine (PII) and thyroid (via T4) status of their dams. [less ▲]

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See detailProlactin-induced activation of nuclear factor kappa B in bovine mammary epithelial cells: Role in chronic mastitis
Boutet, Philippe ULg; Sulon, Joseph ULg; Closset, R. et al

in Journal of Dairy Science (2007), 90(1), 155-164

We sought to determine whether prolactin (PRL) could influence the neutrophilic inflammation that characterizes chronic mastitis. Most of the genes encoding inflammatory proteins depend on the nuclear ... [more ▼]

We sought to determine whether prolactin (PRL) could influence the neutrophilic inflammation that characterizes chronic mastitis. Most of the genes encoding inflammatory proteins depend on the nuclear factor kappa B (NF-kappa B) for their expression. We addressed the hypothesis that immunomodulatory activities of PRL might arise from an increase in NF-kappa B activity. MAC-T cells, a bovine mammary epithelial cell line, were stimulated with increasing concentrations of bovine PRL ( 1, 5, 25, 125, and 1,000 ng/mL). Level of NF-kappa B binding activity was measured and mRNA was evaluated for IL-1 beta, IL-6, IL-8, granulocyte-macrophage colony-stimulating factor (GMCSF), IFN-gamma, and tumor necrosis factor (TNF)-alpha, cytokines known to require NF-kappa B for their maximal transcription. Prolactin activated NF-kappa B; maximal NF-kappa B activation was weaker with PRL than with TNF-alpha at 30 or 180 min poststimulation. In addition, PRL significantly amplified, in a dose-dependent manner, mRNA expression of IL-1 beta, IL-6, IL-8, GMCSF, and TNF-a. We measured PRL concentrations in blood and milk from healthy and chronic mastitis-infected cows, and studied the relationship between the PRL concentration and the degree of inflammation in the mammary gland as indirectly assessed by somatic cell counts (SCC). Plasma PRL did not differ significantly between healthy and chronic mastitis-affected cows (63.7 and 67.5 ng/mL, respectively). Milk PRL concentration was significantly increased in chronic mastitis-affected quarters with the highest SCC, and had a positive significant correlation between SCC, as well as between the number of neutrophils present in milk samples. The present findings show that PRL promotes an inflammatory response in bovine mammary epithelial cells via NF-kappa B activation, and suggest a role for PRL in the pathogenesis of chronic mastitis. [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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See detailComparison of accuracy of transabdominal ultrasonography, progesterone and pregnancy-associated glycoproteins tests for discrimination between single and multiple pregnancy in sheep
Karen, A.; El Amiri, B.; Beckers, Jean-François ULg et al

in Theriogenology (2006), 66(2), 314-322

The aim of the present study was to evaluate and, compare the accuracy of transabdominal ultrasonographic (US) and the progesterone (P4-RIA) and ovine pregnancy-associated glycoprotein (ovPAG-RIA) tests ... [more ▼]

The aim of the present study was to evaluate and, compare the accuracy of transabdominal ultrasonographic (US) and the progesterone (P4-RIA) and ovine pregnancy-associated glycoprotein (ovPAG-RIA) tests for the discrimination between single and multiple pregnancy in sheep. One hundred pregnant Awassi x Merino ewes were scanned by transabdominal ultrasonography (3.5 MHz linear-array transducer) at Days 43-56 and 81 of these ewes were scanned at Days 76-87 of gestation. The ewes were scanned in dorsal recumbency at the bare area of the inguinal regions (without pre-scanning shaving of the ventral abdominal wall). After each scan, blood samples were withdrawn from the jugular vein to estimate the levels of P4 and ovPAG by radioimmumoassay. At lambing, 61 ewes gave birth to single lambs and 39 ewes gave birth to multiples. The sensitivity of the transabdominal US, the P4-RIA and the ovPAG-RIA tests for determining ewes carrying multiples was 54, 64.1 and 64.1% at Days 43-56. At Days 76-87 of gestation these accuracies were 60.0, 66.7 and 76.6% for the US, P4-RIA and PAG-RIA tests, respectively. The specificity of the transabdominal US, the P4-RIA and the ovPAG-RIA tests for determining ewes carrying singles, was 78.6, 60.7 and 62.3% at Days 43-56 and 78.4, 64.7 and 70.6% at Days 76-87 of gestation, respectively. It is concluded that the accuracy of transabdominal ultrasonographic (without pre-scanning shaving of the ventral abdominal wall), the P4- and the ovPAG-RIA tests for determination of the fetal numbers in Awassi x Merino crossbred ewes is too low to be used in the field. (c) 2005 Elsevier Inc. All rights reserved. [less ▲]

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See detailEffects of a single injection of a progesterone receptor antagonist during the third month of gestation in sheep
Taverne, M. A. M.; Regeling, J. I.; Sulon, Joseph ULg et al

in Reproduction in Domestic Animals (2006), 41(4), 310

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See detailEvaluation of GnRH treatment 12 days after AI in the reproductive performance of dairy cows
Szenci, Otto; Takacs, Edit; Sulon, Joseph ULg et al

in Theriogenology (2006), 66(8), 1811-1815

The objective of this study was to evaluate the effects of GnRH administered at Day 12 post-AI on the reproductive performance of dairy cows. Holstein-Friesian dairy cows (n = 103) on a large Hungarian ... [more ▼]

The objective of this study was to evaluate the effects of GnRH administered at Day 12 post-AI on the reproductive performance of dairy cows. Holstein-Friesian dairy cows (n = 103) on a large Hungarian dairy farm were allocated randomly to treated (n = 54) or control (n = 49) groups. Twelve days after AI, treated cows received a GnRH agonist i.m., while the control group received a placebo (physiological saline). Progesterone radioimmunoassay was used to determine the correct timing of artificial insemination (Day 0) and the incidence of luteal insufficiency on Day 12. Ultrasonography and radioimmunoassay for pregnancy-associated glycoprotein were used to detect pregnancy and late embryonic/fetal mortality between Days 32 and 55 after AI. Three cows from each group were inseminated when progesterone concentrations were > 1.0 ng/mL, and six cows (four from the treated and two from the control group) had luteal insufficiency (progesterone < 1.0 ng/mL) on Day 12. Late embryonic/fetal mortality occurred in three treated cows and in two control cows. When these cows were removed from the model, calving rates after first service were 59.6% (28/47) and 59.1% (26/44) for treated and control cows, respectively (P > 0.05). There was no significant difference between treated and control cows when they were inseminated before or after Day 100 from calving. In summary, administration of a GnRH agonist on Day 12 after AI did not improve reproductive performance in dairy cows. However, our approach may be used for the field evaluation of different treatment protocols. (c) 2006 Elsevier Inc. All rights reserved. [less ▲]

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See detailUltrasonographic appearance of the conceptus, fetal heart rate and profiles of pregnancy-associated glycoproteins (PAG) and prostaglandin F-2 alpha-metabolite (PGF(2 alpha)-metabolite) after induction of fetal death with aglepristone during early gestation in cattle
Breukelman, S. P.; Szenci, Otto; Beckers, Jean-François ULg et al

in Theriogenology (2005), 64(4), 917-933

A higher incidence of fetal losses, especially after the use of artificial reproduction techniques, asks for more intensive monitoring of bovine pregnancies. In this study, a model for fetal death (FD ... [more ▼]

A higher incidence of fetal losses, especially after the use of artificial reproduction techniques, asks for more intensive monitoring of bovine pregnancies. In this study, a model for fetal death (FD) was created by administering the antiprogesterone aglepristone twice, at Day 47 and 48 of gestation (n = 5). Control heifers received the solvent (n = 5). The temporal relationships between changes in ultrasonographic appearance of fetal fluids and membranes, fetal heart rate (FHR) and peripheral plasma levels of pregnancy-associated glycoprotein (PAG) and PGF2 alpha-metabolite as determined by radioimmunoassay associated with FD were monitored at eight hour intervals around treatment. For the analysis of plasma levels the period under study was divided into five epochs (T I: before injection of aglepristone/solvent; T2: from first to second injection; T3: from second injection to FD; T4: from diagnosis of FD to 56 h later; T5: from 56 It to 104 h after diagnosis of FD). Control heifers produced healthy calves at term, but in treated heifers, FD occurred on average at 58 (range 48-80) h after first injection of aglepristone. Fetal death was always preceded by a visible reduction of the amount of allantoic fluid and by segregation of the allantochorionic membrane from the endometrium. FHR remained rather constant in both groups, but a (non-significant) drop in FHR around 8 h before FD was diagnosed in four of five treated animals. All fetuses were expulsed after FD. Levels of PAG remained constant or even slightly increased in controls, but decreased in treated animals from T2 onward: levels during T4 and T5 significantly differed from those during T1 and from values in controls during T4 and T5 (P < 0.01). PGF2 alpha-metabolite levels did not change in the controls, but in the treated group they were significantly higher during T3 when compared to T1 (P < 0.05). After this increase, a sharp decrease in PGF2 alpha -metabolite level occur-red, reaching a significantly lower level at T5 when compared to control animals (P = 0.01). It is concluded, that FD induced by aglepristone is preceded by ultrasonographic visible changes in fetal membranes and fluids and a rise in PGF2 alpha-metabolite and is followed by a drop in PAG and PGF2 alpha-metabolite [less ▲]

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See detailSerum osteocalcin and CTX-MMP concentration in young exercising thoroughbred racehorses
Carstanjen, B.; Amory, Hélène ULg; Sulon, Joseph ULg et al

in Journal of Veterinary Medicine. A, Physiology, Pathology, Clinical Medicine (2005), 52(3), 114-120

Bone responds to exercise with changes in bone (re-)modelling, which might be monitored non-invasively with biochemical bone markers. The aim of this study was to evaluate the influence of exercise on ... [more ▼]

Bone responds to exercise with changes in bone (re-)modelling, which might be monitored non-invasively with biochemical bone markers. The aim of this study was to evaluate the influence of exercise on serum osteocalcin and serum carboxy-terminal cross-linked telopeptide of type I collagen generated by matrix metalloproteinases (CTX-MMP) concentration in young racehorses. Seventy-one 2 to 4-year-old Thoroughbreds were included in this prospective infield study. Blood sampling was performed six times (i.e. six sampling cycles) during a 9-month period. Serum samples were analysed with commercial osteocalcin and CTX-MMP radioimmunoassays. Two-year-old racehorses had higher serum osteocalcin and CTX-MMP values than 3-year-old horses. Gender and training amplitude did not significantly influence serum osteocalcin and CTX-MMP values. Two-year-old horses showed an increase in osteocalcin values between cycles 2 and 3 and an increase in serum CTX-MMP values between cycles 1 and 2. Serum osteocalcin and CTX-MMP concentrations decreased between cycles 4 and 5, and 5 and 6. Three-year-old horses showed an increase in serum osteocalcin levels between cycles 3 and 4 and an increase in serum CTX-MMP concentrations between cycles 1 and 2, and 3 and 4. Serum osteocalcin levels decreased between cycles 5 and 6, whereas serum CTX-MMP levels decreased between cycles 4 and 5, and 5 and 6. Two- and three-year-old horses showed a decreased osteocalcin/CTX-MMP ratio between cycles 1 and 2. Moreover, 2-year-old horses showed an increase in the osteocalcin/CTX-MMP ratio between cycles 2 and 3. Sore shin formation did not significantly influence serum osteocalcin and CTX-MMP values. Serum osteocalcin and CTX-MMP are promising bone markers for monitoring exercise induced changes in equine bone metabolism. [less ▲]

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