Joseph Sulon

Plasmatic profiles of pregnancy-associated glycoprotein and progesterone levels during gestation in Churra and Merino sheep.

This study was carried out to determine ovine pregnancy-associated glycoprotein (oPAG) and progesterone (P4) levels in the serum of Churra and Merino ewes throughout gestation and the first month post partum. The oPAG levels were determined with an heterologus RIA using bovine PAG as standard and tracer and rabbit antiserum against oPAG, sensitivity was 4.0 ng/ml. The P4 levels were measured with a radioimmunological procedure, including a specific extraction step with petroleum ether (bp 60-80 degrees C) with a sensitivity of less than 0.1 ng/ml. There were no differences (P<0.10) in the oPAG profile between breeds from Weeks 1 to 18. From Week 18 to lambing, oPAG concentrations increased rapidly in Churra ewes (on average, from 250 to 650 ng/ml) while remaining relatively constant in the Merino ewes (around 250 ng/ml). No significant differences (P>0.05) were observed for mean weekly P4 levels between the 2 breeds. In both breeds, P4 increased throughout the whole length of gestation, with the highest level measured at Weeks 19-20, then declined 2 wk before parturition. No correlation was found between P4 and oPAG concentrations during gestation in either of the breeds. After lambing, oPAG and P4 levels decreased rapidly in 4 wk to basal values. In both breeds the oPAG concentrations at Weeks 19, 20 and 21 of gestation in ewes carrying male fetuses were higher than in those carrying female fetuses. From the results, we conclude that the breed and sex of the fetus could influence the production of oPAG.

Comparison between blood serum and salivary cortisol concentrations in horses using an adrenocorticotropic hormone challenge.

REASONS FOR PERFORMING STUDY In horses, serum cortisol concentration is considered to provide an indirect measurement of stress. However, it includes both free and bound fractions. The sampling method is also invasive and often stressful. This is not the case for salivary cortisol, which is collected using a more welfare-friendly method and represents a part of the free cortisol fraction, which is the biologically active form. OBJECTIVES To compare salivary and serum cortisol assays in horses, in a wide range of concentrations, using an adrenocorticotropic hormone (ACTH) stimulation test, in order to validate salivary cortisol for stress assessment in horse. METHODS In 5 horses, blood samples were drawn using an i.v. catheter. Saliva samples were taken using swabs. Cortisol was assayed by radioimmunoassay. All data were treated with a regression method, which pools and analyses data from multiple subjects for linear analysis. RESULTS Mean ± s.d. cortisol concentrations measured at rest were 188.81 ± 51.46 nmol/l in serum and 1.19 ± 0.54 nmol/l in saliva. They started increasing immediately after ACTH injection and peaks were reached after 96 ± 16.7 min in serum (356.98 ± 55.29 nmol/l) and after 124 ± 8.9 min in saliva (21.79 ± 7.74 nmol/l, P<0.05). Discharge percentages were also different (225% in serum and 2150% in saliva, P<0.05). Correlation between serum and salivary cortisol concentrations showed an adjusted r(2) = 0.80 (P<0.001). The strong link between serum and salivary cortisol concentrations was also estimated by a regression analysis. CONCLUSIONS The reliability of both RIAs and regression found between serum and salivary cortisol concentrations permits the validation of saliva-sampling as a noninvasive technique for cortisol level assessment in horses.

Evaluation of false ultrasonographic diagnoses in cows by measuring plasma levels of bovine pregnancy-associated glycoprotein 1

Between days 27 and 59 after artificial insemination (AI), 189 ultrasonographic pregnancy diagnoses were made in 56 dairy cows using a 7.5 MHz linear-array rectal transducer. Blood samples were withdrawn from a jugular vein on the day of Al, on day 21, and after each ultrasonographic examination between days 27 and 31, days 34 and 38, days 41 and 45 and days 55 and 59 after AI. Plasma concentrations of bovine pregnancy- associated glycoprotein 1 (bPAG-1) were measured by radioimmunoassay. The results showed that before day 31, ultrasonographic scanning was not very sensitive because six of the 30 calving cows were incorrectly diagnosed as non-pregnant. In five of these animals, the uterus was located far cranial to the pelvic inlet. Five of the cows examined between days 27 and 31 were pregnant on the basis of plasma bPAG-1 levels on the same day, using 0.5 ng/ml as the cut-off point. Plasma levels of bPAG-1 and progesterone proved that four of the cows which had early positive ultrasonographic diagnoses but did not produce a calf, were pregnant when they were examined.

Effect of induction of late embryonic mortality on plasma profiles of pregnancy associated glycoprotein 1 in heifers.

Inoculation with Actinomyces pyogenes and administration of prostaglandin (PG)F(2alpha) were used to induce late embryonic mortality (LEM) in heifers (n=8) on Days 30-38 of pregnancy in order to compare the profile for bovine pregnancy associated glycoprotein 1 (PAG1), progesterone and 15-keto-13,14-dihydro-PGF(2alpha) (PGFM). Two pregnant heifers were used as controls. Inoculation into the uterine body caused LEM, as established by ultrasonography in each heifer within 24h of treatment. When the inoculum was injected into the first part of the cervix, LEM occurred in one of two heifers (Heifer A) between 48 and 72 h after treatment. Similarly, PGF(2alpha) treatment caused LEM in three of four heifers. In six of eight heifers, PAG1 started to decrease steadily when it was accompanied by the subsequent death of the embryo. Inoculation through the cervix caused luteolysis in three of four heifers within 6-10 days after induction. After induction of LEM, PGFM concentrations showed a two to 3.8 fold increase in three of four heifers during the following six days, and from that time changed within normal ranges. The results of this study indicate that a PAG1 assay may provide an alternative method to ultrasonography for determining LEM in the cow.

Plasma pregnancy-associated glycoprotein and progesterone concentrations in pregnant Assaf ewes carrying single and twin lambs

Ovine pregnancy-associated glycoprotein (oPAG) and progesterone (P4) concentrations were monitored weekly during the last three months of gestation and the first month postpartum in plasma of twelve Assaf ewes. The oPAG levels were determined with a heterologous RIA using bovine PAG as standard and tracer and rabbit antiserum against oPAG. The P4 levels were measured with a radioimmunological procedure with a sensitivity to less than 0.1 ng ml−1. The oPAG profiles in ewes carrying a single lamb and in those carrying twins were very similar from week 9 of gestation to lambing. Ewes which had twins presented numerically higher oPAG concentrations from week 12 to lambing, but that difference was only significant (P 0.05) was found between oPAG concentrations and lamb birth-weight at any week of gestation considered in this study. However, the lamb birth-weight was positively correlated (P < 0.10) with the P4 concentrations from weeks 9 to 19 of gestation. Results indicate that number of fetuses could influence the oPAG production in ewes during the last three months of gestation.

Cyclical Cushing's disease and its successful control under sodium valproate.

Several subgroups of Cushing’s disease were recently described (anterior or intermediate lobe origin, hyper-or hypo-pulsatility of Cortisol, presence or absence of response after GRH or TRH, cyclical Cushing’s disease). We present here a detailed case report on a patient suffering from Cushing’s disease whose endocrine functions were extensively investigated. Treatment with bromocriptine, as well;as subsequent transsphenoidal surgery, were followed by rapid but transient reversal of symptoms. When clinical manifestations reoccurred, daily measurements of free urinary Cortisol revealed a cyclic pattern of Cortisol hyperexcretion. A study of ultradian rhythm revealed hyperpulsatility of Cortisol secretion. More interestingly, a treatment with sodium valproate, a drug known to inhibit CRH production, was followed by a rapid and longstanding normalization of clinical and biological data for 2 years. Based on these data, and on information from the literature, the present case of Cushing’s disease exhibits characteristics suggesting a possible hypothalamic origin.

Determination of pregnancy-associated glycoprotein concentrations in goats (Capra hircus) with unsuccessful pregnancies: a retrospective study.

Presented here are the profiles of pregnancy-associated glycoprotein (PAG) concentrations in blood collected weekly from goats experiencing maintained and unsuccessful pregnancies. The analysis of these profiles clearly indicated 4 different situations: the pseudopregnancy syndrome, abortion between Days 89 and 137, parturition of 1 dead and 1 live fetus, and expulsion of macerated or mummified fetuses after full term. A marked reduction in PAG concentration at any time during pregnancy was followed by an event such as abortion or the expulsion of a dead fetus at term or later.

Hormonal correlates of gonadal regression and spontaneous recovery in Japanese quail exposed to short day-lengths

Adult male Japanese quail were transferred from long to short days. Plasma testosterone and dihydrotestosterone quickly decreased and this endocrine response was followed by a regression of the cloacal gland, an androgen-target organ. After about a month, a spontaneous recovery of gonadal activity was observed in some but not all birds. It was not associated with obvious shifts in the circadian system. The physiological bases of this spontaneous recovery are discussed as well as the detailed relationships between plasma testosterone and cloacal gland size.

Factors Affecting Plasma Pregnancy-associated Glycoprotein 1 Concentrations Throughout Gestation in High-producing Dairy Cows

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.

Pregnancy-associated glycoprotein levels in pregnant goats inoculated with bartoxoplasma gondii or barlisteria monocytogenes : a retrospective study

The pregnancy-associated glycoprotein (PAG) concentration profiles of goats that had been experimentally inoculated with either Toxoplasma gondii or Listeria monocytogenes are described. All goats were examined regularly by ultrasonography. In T. gondii-infected females (n = 5), a slow decrease of PAG was observed throughout a period of 55 to 74 d after inoculation. Afterwards, the goats either aborted (n = 4) or kidded 1 dead and 1 weak fetus (n = 1). In L. monocytogenes-infected females (n = 8), a marked decrease of PAG was observed from the day of inoculation. Abortion occurred within 9 to 11 d post inoculation (n = 7). Only 1 goat kidded a healthy fetus.