References of "Beckers, Jean-François"
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See detailProsztaglandin kezelés hatása a sárgatestre, a plasma progeszteron koncentrációra és a graaf-féle tüszöre
Repasi, Attila; Beckers, Jean-François ULg; Sulon, Joseph ULg et al

in Szenci, Ottó; Brydl, Endre; Jurkovich, Viktor (Eds.) Proceedings: 16.Magyar Buiatrikus Kongresszus - The effect of herd health of cattle, sheep and goat on the profitable production (1995)

The results of three different prostaglandin treatment protocols are summarized in our summary: In the first experiment the effects of different doses (0 mg, 25 mg vs 35 mg) of prostaglandin treatments ... [more ▼]

The results of three different prostaglandin treatment protocols are summarized in our summary: In the first experiment the effects of different doses (0 mg, 25 mg vs 35 mg) of prostaglandin treatments from the day of treatment (Day 0) were examined. The percentage changes relative to the corpus luteum area decreased, and the percentage changes relative to the largest follicle area increased faster, and even the oestrus started sonner in cocas treated with 35 mg PGF2a than in those treated with 25 mg PGF2a. However, these differences between groups were not statistically significant. At the same lime, the decrease in the percentage changes relative to the area of corpora lutea and to the concentrations of P4 was statistically significant in both groups. In the second experiment treatment of dairy cows with 2 luteolytic dosages of PGF2a or its synthetic analogue at an 8-h interval resulted in more cows (non-significantly) (18 vs. 21) being observed in oestrus within 5 d after treatment and having significantly higher conception rate (27,8% vs. 66,6%) than with 1 treatment. Further studies in progress should confirm the benefit of 2 prostaglandin treatments in a larger scale. At the same lime, the type and the number of prostaglandin treatments had no effect on the incidence of ovulations alter oestrus, the number of ovulations without oestrous signs, the number of cows without oestrus and ovulation, and the average lime from treatment to oestrus. In the third experiment the lime of ovulation was examined alter detected oestrus and A.I. (Day 0) in prostaglandin treated and non-treated dairy cows. Large variations in the area of the CL were detected in the prostaglandin treated and untreated cows. The areas of the largest follicles in treated cows were somewhat smaller during the experiment, than those in untreated cows however those differences between the groups and within the groups were not statistically significant. The area of the largest follicle in cows with no ovulation also did not differ significantly. Some of the cows (n=7) in treated and non-treated groups did not ovulate at all during the experiment. The mean area of the ovulatory follicle on the day before ovulation was somewhat greater but not significantly, if ovulation occurred later regarding to AI, The overall conception rate was > 50% in both groups, but when the cows ovulated too early or too late in relation to the lime of AI the conception rate was significantly louver, therefore determination of the optimal lime for AI is of great practical importance. If ovulation does not occur within two days alter AI second AI may be recommended. Further studies are needed to evaluate the benefit of the second AI [less ▲]

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See detailA novel glycoprotein of the aspartic proteinase gene family expressed in bovine placental trophectoderm
Xie, Sancai; Low, Boon G.; Nagel, Robert J. et al

in Biology of Reproduction (1994), 51(6), 1145-1153

The pregnancy associated glycoproteins (PAG 1) that appear in the maternal serum of cattle and sheep soon after implantation are apparently inactive members of the aspartic proteinase family. Here we ... [more ▼]

The pregnancy associated glycoproteins (PAG 1) that appear in the maternal serum of cattle and sheep soon after implantation are apparently inactive members of the aspartic proteinase family. Here we describe the isolation of a highly abundant cDNA (PAG 2 cDNA) that represents a second member of this gene family which is structurally related to bovine PAG 1, ovine PAG 1, and pepsin (58%, 58%, and 51% amino acid sequence identity, respectively). The bovine PAG 2 cDNA was identified in two ways. First, the bovine placental library was screened under relatively nonstringent conditions with an ovine PAG 1 cDNA. The second fortuitous approach employed immunoscreening with an antiserum raised against a partially purified factor that competed with bovine LH for binding to the LH receptor on the CL of the ovary. The full-length cDNA (1258 bp) codes for a polypeptide of 376 amino acids. Bovine PAG 2, unlike bovine PAG 1, has a catalytic center with a consensus sequence of amino acids. Its mRNA is expressed in fetal placenta but not in other fetal organs, and is localized to both the mononucleate and binucleate cells of the trophectoderm, whereas PAG 1 is expressed only in binucleate cells. PAG 2 is synthesized by placental explants as a 70-kDa glycoprotein that is processed to several smaller molecules. Western blot analysis of culture media developed with epitope-selected antibodies to PAG 2 reveals several bands ranging in apparent M(r) from 31,000-70,000, which correspond in size to the polypeptides present in the preparation used for immunization [less ▲]

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See detailPlasmatic profiles of pregnancy-associated glycoprotein and progesterone levels during gestation in Churra and Merino sheep
Ranilla, Marie-José; Sulon, Joseph ULg; Carro, M. D. et al

in Theriogenology (1994), 42(3), 537-545

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 ... [more ▼]

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°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. [less ▲]

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See detailMolécules de la famille des protéases aspartiques dans le placenta des ruminants: hormones ou protéines ?
Beckers, Jean-François ULg; Roberts, R. Michael; Zoli, André Pagnah et al

in Bulletin et Mémoires de l'Académie Royale de Médecine de Belgique (1994), 149(8-11), 355-367

The placenta of ruminant contains binucleate trophoblastic cells synthesizing proteins, migrating cross the barrier and fusing with endothelial cells of the endometrium. Recently described were two ... [more ▼]

The placenta of ruminant contains binucleate trophoblastic cells synthesizing proteins, migrating cross the barrier and fusing with endothelial cells of the endometrium. Recently described were two glycoproteins from the family of aspartic proteases, apparently lacking the enzymatic activity: the pregnancy associated glycorproteins I and II (PAGI and PAGII). The first (PAGI) is largely secreted in maternal blood, this characteristic copes with the lack of proteolytic activity. The second (PAGII) is not completely characterized. However, it binds to lutropin (LH) receptors with high affinity. This binding allows to assume that PAGII is likely the same as the bovine chorionic gonadotropin identified earlier (bCG). A better characterization of these glycoproteins (PAGI and PAGII) and other members of the family (PAGIII...) will answer these questions together with the unexplained invasive process of the placenta. [less ▲]

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See detailIsolation and characterization of preantral follicles from fetal bovine ovaries
Hulshof, S. C. J.; Figueiredo, José Ricardo; Beckers, Jean-François ULg et al

in Veterinary Quarterly (The) (1994), 16(2), 78-80

A simple, mechanical method is described for the isolation of preantral follicles bovine foetuses of 220-280 days of gestation. On average, 2918+621 (s.d.) preantral follicles were isolated per ovary. The ... [more ▼]

A simple, mechanical method is described for the isolation of preantral follicles bovine foetuses of 220-280 days of gestation. On average, 2918+621 (s.d.) preantral follicles were isolated per ovary. The isolated preantral follicles were characterized on the basis of the morphological appearance of the surrounding granulosa cells, the number of granulosa cell layers, and their diameter. The results show that primordial, primary, and secondary follicles differ morphologically and that they can be classified by their diameter. [less ▲]

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See detailImmunocytochemical localization of vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY) in the bovine ovary
Hulshof, S. C. J.; Dijkstra, G.; Van der Beek, E. M. et al

in Biology of Reproduction (1994), 50(3), 553-560

The distribution of the neuropeptides vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY) was studied immunocytochemically in bovine ovaries from 3 mo of gestation up to and including puberty ... [more ▼]

The distribution of the neuropeptides vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY) was studied immunocytochemically in bovine ovaries from 3 mo of gestation up to and including puberty, and from adult cows at three stages of the estrous cycle. The appearance of VIP and NPY immunoreactivity of 4.5-6 mo of gestation coincided with the onset of follicular development. In contrast to NPY, VIP was first found in the cortex. Both VIP and NPY immunoreactivity increased with age. From 9 mo of gestation onwards, VIP and NPY were found around blood vessels and non-vascular smooth muscle cells, in the stroma near preantral follicles, and in the theca externa of antral follicles. In addition, VIP-positive cells were observed exclusively in the granulosa layer of the preovulatory follicle at the time of the LH surge. The distribution of VIP- and NPY-immunoreactive fibers in the ovary may point to an effect of these neuropeptides on various physiological processes, including follicle development and ovarian blood flow. In addition, the presence of VIP-positive cells in the granulosa layer of the preovulatory follicle is indicative of a role for VIP in ovulation. [less ▲]

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See detailLe point sur la production d’embryons in vitro: limitations et perspectives de la recherche
Thonon, Fabienne; Ectors, Fabien ULg; Delval, Alain et al

in Annales de Médecine Vétérinaire (1994), 138(1), 33-40

Recent progress in gamete biology and early embryo development was responsible for great evolution of reproduction techniques in farm animals. Among these techniques, in vitro production of bovine embryos ... [more ▼]

Recent progress in gamete biology and early embryo development was responsible for great evolution of reproduction techniques in farm animals. Among these techniques, in vitro production of bovine embryos was developed from slaughterhouse ovaries. This method has been used for individual animals. However, large variations in results were observed, due to several factors, including reproductive state and age of the donor. Inspite of this limitation, in vitro production of bovine embryos may be helpful, when slaughtering of valuable cows is recommended eg for brucellosis disease. Researches are purchased in order to increase the number of oocytes obtained per "elite" cow and to improve the ability of in vitro embryos to support freezing. [less ▲]

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See detailPreservation of Oocyte and Granulosa Cell Morphology in Bovine Preantral Follicles Cultured in Vitro
Figueiredo, J. R.; Hulshof, S. C.; Van den Hurk, R. et al

in Theriogenology (1994), 41(6), 1333-46

Described in the present paper is a culture system that preserves oocyte and granulosa cell morphology in bovine preantral follicles during 5 d in vitro. The effects of additional hypoxanthine and energy ... [more ▼]

Described in the present paper is a culture system that preserves oocyte and granulosa cell morphology in bovine preantral follicles during 5 d in vitro. The effects of additional hypoxanthine and energy substrata (i.e., pyruvate and glutamine) on the morphology of cultured preantral follicles were investigated. It was shown that addition of a mixture of pyruvate, glutamine and hypoxantine to the culture medium increased the percentage of follicles with an intact oocyte from 29.4 to 78.6%. Morphological criteria are described to discriminate between normal and degenerated preantral follicles during culture by inverted microscopy. In addition, the importance of histological evaluation to judge the quality of oocyte and granulosa cells is demonstrated. [less ▲]

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See detailModification of immunoreactive EGF receptor after acute tubular necrosis induced by tobramycin or cisplatin
Leonard, I.; Zanen, J.; Nonclercq, D. et al

in Renal Failure (1994), 16(5), 583-608

Acute tubular necrosis induced by aminoglycoside antibiotics and various other nephrotoxins is followed by a regenerative process which leads to the restoration of damaged tubules. Several lines of ... [more ▼]

Acute tubular necrosis induced by aminoglycoside antibiotics and various other nephrotoxins is followed by a regenerative process which leads to the restoration of damaged tubules. Several lines of evidence indicate that tubular regeneration is mediated by polypeptide growth factors such as epidermal growth factor (EGF). Previous studies devoted to cisplatin nephrotoxicity have shown that this agent causes tubular cystic degeneration possibly related to an impairment of renal tissue repair. Thus, we examined on a comparative basis the time course of the regenerative response subsequent to tubular damage induced by tobramycin or cisplatin, particular attention being paid to renal EGF and its receptor. Female Sprague-Dawley rats (160-180 g body weight) were treated during 4 consecutive days with daily doses of 200 mg/kg tobramycin i.p. (BID) or 2 mg/kg cisplatin (once a day). Sham-treated rats were given 0.9% NaCl i.p. following the same protocol. Groups of experimental animals (n = 5-10) were terminated at increasing time intervals (1, 4, 7, 14, 21, 60 days) after cessation of treatment. One hour prior to sacrifice, each individual received i.p. 200 mg/kg 5-bromo-2'-deoxyuridine (BrdU) for the immunohistochemical demonstration of cell proliferation. Blood was collected at the time of sacrifice in order to assess glomerular filtration rate by measuring serum creatinine and BUN levels. Kidneys were analyzed with respect to total EGF determined by RIA in renal tissue homogenates, and soluble EGF was assayed in extracts prepared by centrifugation. Renal tissue was processed for the immunohistochemical detection of S-phase cells, of EGF, of EGF receptors, and of the intermediate filament vimentin, the latter being used as a marker of epithelium dedifferentiation. In absence of nephrotoxic alterations, EGF was immunolocalized in distal tubules, whereas EGF receptor immunostaining was seen in proximal tubules cells. Vimentin immunostaining was confined to glomeruli and blood vessels. Tobramycin and cisplatin caused acute tubular necrosis in proximal convoluted tubules and proximal straight tubules, respectively. Tissue damage was accompanied by renal dysfunction reflected by an elevation of serum creatinine and BUN levels. Tubular necrosis was followed by a proliferative response indicative of tubular regeneration. Regenerative hyperplasia was associated with a reduction of total immunoreactive EGF due to a decrease of tissue-bound proEGF. Tubules undergoing regenerative repair were characterized by a disappearance of EGF receptors and the presence of immunoreactive vimentin. In tobramycin-treated rats, renal dysfunction lasted for 4-7 days and was fully reversible, as indicated by the return of serum markers to normal values. [less ▲]

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See detailClonage par greffe de blastomère: naissance d'un premier veau
Ectors, Fabien ULg; Delval, Alain; Touati, Kamal ULg et al

in Annales de Médecine Vétérinaire (1993), 137(8), 573-574

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See detailDevelopment of a combined mechanical and enzymatic method for the isolation of intact preantral follicles from fetal, calf and adult bovine ovaries
Figueiredo, José Ricardo; Hulshof, S. C. J.; Van den Hurk, R. et al

in Theriogenology (1993), 40(4), 789-799

The isolation of preantral follicles from the ovaries of bovine fetuses, calves and adult cows was performed using a simple, rapid mechanical and enzyme method. The ovaries were cut into small pieces with ... [more ▼]

The isolation of preantral follicles from the ovaries of bovine fetuses, calves and adult cows was performed using a simple, rapid mechanical and enzyme method. The ovaries were cut into small pieces with a tissue chopper. Then, the suspension was filtered successively through 500 and 100 μm nylon mesh filters. This simple mechanical procedure resulted in large numbers of isolated preantral follicles: 2,142 ± 254; 512 ± 92 and 298 ± 54 from the ovaries of bovine fetuses, calves and cows, respectively. In addition, the ovarian fragments between 100 and 500 μm were suspended in 10 ml of M199 Hepes medium plus 5% FCS and divided into 2 equal parts: one portion was used for collagenase treatment (200 U/ml) for 20 minutes, while the other served as a control. Collagenase treatment resulted in 841 ± 161; 216 ± 51 and 52 ± 17 preantral follicles from fetuses, calves and cows, respectively, compared with 312 ± 86; 52 ± 15 and 10 ± 2 in the control group. The use of collagenase with ovarian fragments selected by filtration as a method for increasing the rate of recovery of preantral follicles is described here. [less ▲]

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See detailLe clonage par transfert de noyau dans l'espèce bovine: premiers résultats
Ectors, Francis ULg; Ectors, Fabien ULg; Delval, Alain et al

in Bulletin et Mémoires de l'Académie Royale de Médecine de Belgique (1993), 148

In 1987, Prather et al. have performed the first embryo cloning by nuclear transfer in the bovine species. Since, many researchers try to develop and to apply the technique. While the enucleation of the ... [more ▼]

In 1987, Prather et al. have performed the first embryo cloning by nuclear transfer in the bovine species. Since, many researchers try to develop and to apply the technique. While the enucleation of the recipient oocyte, the injection of the donor blastomere and the fusion procedure are now well controlled, on the other hand, maturation and activation as the development and freezing of the cloned embryos need tobe more investigated. The cloned embryo is more fragile. An increase in embryonic mortality is observed after transfer in a recipient cow. [less ▲]

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See detailClonage par transfert de noyau dans l'espèce bovine: premiers résultats
Ectors, Fabien ULg; Delval, Alain; Touati, Kamal ULg et al

in Annales de Médecine Vétérinaire (1993), 137(6), 427-431

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See detailLight and Electron microscopic immunolocalization of Bovine pregnancy-associated glycoprotein in the Bovine Placentome
Demez, Pierre ULg; Zolli, A. P.; Beckers, Jean-François ULg et al

in 1st Joint meeting of the Royal Microscopical society and the Belgian Societies for Cell biology, clinical cytology, Electron Microscopy and pathology-Abstract book (1993)

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See detailComparison between culture of bovine embryos in vitro versus development in rabbit oviducts and in vivo
Ectors, Fabien ULg; Thonon, Fabienne; Delval, Alain et al

in Livestock Production Science (1993), 36

The aim of this work was to evaluate the efficiency of different embryo culture methods for in vitro embryo production: development in co-culture with bovine oviductal epithelial cells (BOEC), in BOEC ... [more ▼]

The aim of this work was to evaluate the efficiency of different embryo culture methods for in vitro embryo production: development in co-culture with bovine oviductal epithelial cells (BOEC), in BOEC conditioned medium (CM) or in rabbit oviducts, versus in vivo produced embryos. There was no significant difference in terms of percentages of cleaved and 8-cell stages obtained between CM and BOEC. In CM, 24.8% of the cleaved embryos became blastocysts. In BOEC, 14.5% of the cleaved embryos became blastocysts. Among the 190 zygotes transferred in the rabbit oviducts, 127 have been recovered 5 days later, and 17.4% became blastocysts. There was no significant difference in term of blastocyst formation between the development in rabbit and in BOEC. However, there was a significant difference between the CM group and the two other groups. The numbers of cells in blastocysts from different sources were investigated: in vivo blastocysts contained 107 cells assumed to be 100%, in vitro blastocysts developed in rabbit oviduct 100.1 cells (93.3%), BOEC blastocysts 90.8 cells (84.6%) and CM blastocysts 72.3 cells (67.3%). This study confirmed earlier works on the oviduct effect on blastocyst quality in terms of development rate and cell number. [less ▲]

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See detailEffect of estradiol supplementation on superovulation in swamp buffalo
Uoc, N. T.; Nguyen, B. X.; Ty, L. V. et al

in Theriogenology (1992), 38(3), 471-478

The effect of estradiol-17β (E2) supplementation on superovulation with (PMSG) or (FSH) was investigated in Swamp buffalo. Sixty-eight buffalo were treated in seven groups. Group 1 served as control and ... [more ▼]

The effect of estradiol-17β (E2) supplementation on superovulation with (PMSG) or (FSH) was investigated in Swamp buffalo. Sixty-eight buffalo were treated in seven groups. Group 1 served as control and was superovulated by standard PMSG or FSH treatment used in routine bovine embryo transfer protocols. Group 2 was superovulated by standard PMSG regimen plus two injections of E2 at a 48 h interval beginning one day before the onset of gonadotropin treatment (short-term supplementation) for a total dosage of 2.5 mg E2; Groups 3 and 4 received the same regimen as Group 2, but in doses of 5.0 and 7.5 mg E2, respectively. Group 5 received the standard FSH regimen (40% LH). Group 6 received short-term E2 (7.5 mg) supplementation of FSH-p. Group 7 was superovulated by standard FSH regimen (40% LH) plus three injections of E2 at 48–72 h intervals beginning five days before the onset of gonadotropin treatment (long-term supplementation) for a total dosage of 7.5 mg E2. The number of corpora lutea (CL) and follicles ≥ 8 mm in diameter were recorded by palpation per rectum and after slaughter. The mean numbers of CL and follicles were 0.99, 5.8, 8.0, 10.6, 4.0, 3.9, 8.1 and 0.25, 6.8, 6.2, 6.2, 1.6, 0.0, 4.1 for Groups 1, 2, 3, 4, 5, 6, 7, respectively. In Group 7, the rates of nonsurgical and postmortem embryo recovery were 46 and 90.4%, respectively and 54.4% of the collected ova were fertilized. These results indicate the possibility of producing viable embryos in buffalo by using E2 supplementation for the gonadotropin treatment. [less ▲]

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See detailEffects of repeated use of progestagen-PMSG treatment for estrus control in dairy goats out of breeding season
Baril, Gérard; Remy, Benoît ULg; Vallet, J. C. et al

in Reproduction in Domestic Animals (1992), 27(3), 161-168

Contents: In order to analyze the effects of repeated use of progestagen-PMSG treatment, estrus and pregnancy results have been analyzed for 1989 in a Saânen dairy goat herd in which breeding takes place ... [more ▼]

Contents: In order to analyze the effects of repeated use of progestagen-PMSG treatment, estrus and pregnancy results have been analyzed for 1989 in a Saânen dairy goat herd in which breeding takes place each year out of season after FGA/PMSG treatment. After the first 1989 treatment (169 goats), percentage of goats showing estrus and kidding have been lower for 59 multiparous than for 46 primiparous and 64 nulliparous females. Moreover, when 38 goats are treated for a second time in 1989, 44.7% exhibited estrus vs 71.0% after the first treatment (P < 0.05). The PMSG binding level before the 1st 1989 treatment is higher for multiparous (17.5 ± 23.1%) than nulli and primiparous (-0.06 ± 0.7 and 1.2 ± 1.9%) and is increased for all parities after treatment (23.2 ± 26.4 after vs 5.7 ± 15.0% before, P < 0.01). For nulliparous and primiparous females; PMSG binding levels are not different for pregnant or not pregnant nulliparous and primiparous goats. On the opposite, PMSG binding rates are higher in non pregnant (25.7 ± 23.3) than in pregnant multiparous goats (6.5 ± 15.9) (P < 0.01). However, when the binding rate is ≤ 5.12% (computerized distributions) multiparous goats exhibit estrus and pregnancy at levels not different from nulliparous or primiparous females (% estrus 95.8 vs 100 or 97.8%, % pregnancy 66.7 vs 70.3 and 63.0% respectively). Repeated use of PMSG during the female life or during one given year leads to active immunization against PMSG (as measured by percentage of binding of PMSG in plasma) decreasing the efficiency of ovarian stimulation out of breeding season. [less ▲]

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See detailRadioimmunoassay of a Bovine Pregnancy-Associated Glycoprotein in Serum: Its Application for Pregnancy Diagnosis
Zoli, André Pagnah; Guilbault, Louis A; Delahaut, Philippe et al

in Biology of Reproduction (1992), 46(1), 83-92

A sensitive and specific double-antibody RIA for a bovine pregnancy-associated glycoprotein (bPAG) is described. The limit of detection was 0.2 ng/ml. The assay was specific for bPAG in that pituitary and ... [more ▼]

A sensitive and specific double-antibody RIA for a bovine pregnancy-associated glycoprotein (bPAG) is described. The limit of detection was 0.2 ng/ml. The assay was specific for bPAG in that pituitary and placental gonadotropic hormones and other placental or serum proteins assayed in serial dilutions did not cross-react. The RIA allowed measurement of bPAG in placental extracts, fetal serum, fetal fluids, and serum or plasma of pregnant cows. About 20% of unbred heifers and nonpregnant cows had detectable levels ranging from 0.30 +/- 0.09 to 0.50 +/- 0.17 ng/ml (mean +/- SD), and 15% of bull sera showed higher concentrations (3.01 +/- 1.73 ng/ml) of bPAG or bPAG-like protein. Variations among animals was observed in fetal serum bPAG concentrations. Bovine PAG was detected in maternal peripheral blood at Day 22 of pregnancy (mean +/- SD, 0.38 +/- 0.13 ng/ml) in some animals and at Day 30 in all pregnant cows. Peripheral serum bPAG levels increased progressively to 3.60 +/- 1.73 ng/ml (mean +/- SD) at Day 30 of pregnancy, to 24.53 +/- 8.81 ng/ml at Day 120, and to 1551.91 +/- 589.68 ng/ml at Day 270. Peak concentration of bPAG was 2462.42 +/- 1017.88 ng/ml and it occurred 1-5 days prior to parturition. After delivery, bPAG concentrations decreased steadily to 499.63 +/- 267.20 ng/ml at Day 14 postpartum (pp), 10.12 +/- 7.84 ng/ml at Day 60 pp, and 1.44 +/- 1.08 ng/ml at Day 90 pp. The undetectable concentration (less than 0.20 ng/ml) was reached by Day 100 +/- 20 pp. An investigation undertaken in Holstein heifers, Holstein cows, and Hereford cows used as recipients for purebred Holstein embryos supplied evidence of the influence of breed of recipient and sex of fetuses on peripheral concentrations of bPAG. A herd of 430 Holstein-Friesian heifers that had received transferred embryos were bled at Day 35 postestrus (pe) for measurement of bPAG. The bPAG was detected in 287 of 430 serum samples analyzed. By rectal palpation performed at Day 45 pe, 267 heifers with detectable levels of bPAG at Day 35 pe were confirmed to be pregnant as were 3 of 143 heifers previously diagnosed as not pregnant by RIA. These results suggest that detection of this placental-specific antigen in the serum could be used as a specific serological method for early pregnancy diagnosis in cattle from 28 days after breeding. [less ▲]

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See detailLight and electron microscopic immunolocalization of bovine pregnancy-associated glycoprotein in the bovine placentome.
Zoli, A.; Demez, Pierre ULg; Beckers, Jean-François ULg et al

in Biology of Reproduction (1992), 46(4), 623-9

A bovine pregnancy-associated glycoprotein (bPAG) of 67 kDa has previously been isolated from bovine fetal cotyledons. The objective of this study was to determine the cytological localization of that ... [more ▼]

A bovine pregnancy-associated glycoprotein (bPAG) of 67 kDa has previously been isolated from bovine fetal cotyledons. The objective of this study was to determine the cytological localization of that protein in the placentomes and possibly the cells responsible for its production. Highly specific antisera raised against pure bPAG were used to demonstrate the cellular localization of the protein in bovine placentomes by light and electron microscopic techniques. Strong immunostaining was observed exclusively in the cytoplasm of large binucleate cells present predominantly in fetal cotyledonary tissue (villi). Some smaller weakly immunostained cells were also present in caruncular epithelium. By ultrastructural immunogold procedures, the protein was detected only within amorphous cytoplasmic granules. Granules of identical size, but weakly labeled, were found on the maternal side. All cells containing labeled granules were binucleate. These results suggest that bPAG is probably synthesized by trophoblast binucleate cells and stored in granules prior to delivery into the maternal circulation after cell migration. [less ▲]

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