Increase of Plasma Ecg Binding Rate after Administration of Repeated High Dose of Ecg to Cows

in Reproduction Nutrition Development (2001), 41(3), 207-215

Equine chorionic gonadotrophin (eCG) is still used to promote follicular growth in cattle and, more recently with an increased frequency of administration, in ovum pick-up protocols. The aim of this ... [more ▼]

Equine chorionic gonadotrophin (eCG) is still used to promote follicular growth in cattle and, more recently with an increased frequency of administration, in ovum pick-up protocols. The aim of this experiment was to verify the possible effect of high frequency of administration on the immune response to eCG. The profiles of eCG binding rate, in the blood of two groups (A, B) of 4 primiparous cross breed beef cows (3-3.5 years old) submitted weekly for 5 to 10 weeks to repeated high doses (1000-2000 IU) of equine chorionic gonadotrophin, are presented in this paper. A sensitive radiometric method was used to detect antibodies in plasma. The profiles clearly indicated a marked increase of eCG binding rate after 3 to 5 injections of the exogenous hormone to the females. The statistical analysis of the results established that treatments induced a significant increase (P < 0.01) in binding rates after 6 and 3 injections in group A and B respectively. These binding rates remained elevated for at least 1 week following the last injection and decreased afterwards. The values of plasma binding rates following repeated eCG administration differed significantly between groups (0.90+/-1.04 and 1.04+/-0.11 for groups A and B before treatment versus 11.77+/-0.92, 6.70+/-0.85 for groups A and B after treatment, P < 0.01) and from one cow to another (P < 0.01) with some cows presenting no significant immune response while others were more reactive against the hormone (at least 3 injections). [less ▲]

Radioimmunoassay of porcine pepsinogen

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2001), 5(1), 25-26

Pregnancy-associated glycoproteins in the ruminants: inactive members of the Aspartic Protease family

in Proceedings of the Middel European Buiatrics Congress, 1998 (1998, May 21)

Proteins secreted by the placenta, when detected in the peripheral circulation of the mother, can be useful indicators of both pregnancy and feto-trophoblast well-being (1-3). In 1982, Butler et al. (4 ... [more ▼]

Proteins secreted by the placenta, when detected in the peripheral circulation of the mother, can be useful indicators of both pregnancy and feto-trophoblast well-being (1-3). In 1982, Butler et al. (4) isolated two pregnancy-specific proteins (PSPA and PSPB) from bovine placental membranes. PSPA was identified as a-fetoprotein which is not strictly limited to pregnancy, while PSPB was confirmed as placenta’s and pregnancy’s specific (5). PSPB was characterized as a glycoprotein showing relative molecular masses (Mr) between 47 and 53 kDa and presenting different isoelectric points (from 4.0 to 4.4). The Mr of PSPB was similar to the Mr of the molecule isolated by Laster in 1977 (6). In 1991, Zoli et al. (7) purified a pregnancy-associated glycoprotein (PAG), later designated PAG_1 and presently designated as PAG_I_ 67 considering its Mr. When isolated from bovine fetal cotyledons PAG_I_67 was an acidic glycoprotein of 67 kDA. Four isoforms (PI : 4.4, 4.6, 5.2 and 5.4) were detected in the initial preparation. Later molecular cloning studies showed that the PSPB and PAG_I_67 were closely related in primary structure (8). These glycoproteins (either PSPB and PAG_I_67) could be detected in the maternal circulation at around the time that the trophoblast formed definitive attachment to the uterine wall (figures A & B). Concentrations increased gradually therefore and reached peak values just before parturition at about 1 to 5 mg/ml (9).The PSPB and PAG molecules are routinely determined in peripheral maternal blood as pregnancy markers in cattle (5, 9,10). Glycoproteins immunologically related to PAG_I_67 and PSPB have been isolated and partially characterized from ovine fetal cotyledons: oPAG later designated oPAG_I (11) and oPSPB (12). They also have been detected in maternal blood by week third (12) or fourth (13) after breeding. Different forms (differing in Mr and isoelectric point) were characterized after isolation from sheep cotyledons cultured in vitro (14). Very recently, 3 different PAGs were characterized from goat placenta having Mr of 55, 59 and 62 kDa. Each of them presented various isoeletric points (15). In 1991, Xie et al., cloned PAG (now known as PAG_I_67) from late bovine and ovine placenta by screening cDNA libraries with two anti-PAG antisera (16). The bovine and ovine cDNAs encoding PAG_I shared 86% nucleotide sequence identic with one and other and encoded proteins of 380 and 382 aminoacids respectively including a 15 aminoacid signal sequence. However, protein sequence data, (peptidic sequencing) already showed the first aminoacid of the bovine PAG_I_67 was an arginine that corresponded to another one located at position 39, downstream of the side of signal sequence cleavage, indicating that PAG_I_67 undergoes post-translational modifications from a proform. [less ▲]

Isolation and partial characterization of a pregnancy-associated glycoprotein (PAG) family from the goat placenta

in Biology of Reproduction (1998), 58(1), 109-115

Antigen(s) immunologically related to pregnancy-associated glycoproteins (PAGs) have previously been detected in the serum of pregnant goats. In this work, we describe a partial characterization of a ... [more ▼]

Antigen(s) immunologically related to pregnancy-associated glycoproteins (PAGs) have previously been detected in the serum of pregnant goats. In this work, we describe a partial characterization of a family of PAGs isolated from the placenta of the goat. The procedure, monitored by RIA, included extraction of proteins at neutral pH, acidic, and ammonium sulfate precipitations; and gel filtration and ion exchange chromatographies. Immunoreactivity, initially located in the acidic supernatant and in the 40-80% ammonium sulfate fractions, was equally apportioned between the 0.04 and 0.08 M NaCl DEAE fractions. After further purification of both DEAE fractions, the preparations were subjected to one- and two-dimensional electrophoresis, and individual polypeptides were analyzed by amino acid sequencing. Three PAGs, which differed in amino acid sequence and apparent molecular masses (62, 59, and 55 kDa), were detected, each containing several isoforms with different pls: caprine (c) PAG62 (pl: 5.1, 4.8), cPAG59 (pl: 6.2, 5.9, 5.6), and cPAG55 (pl: 5.3, 5.1, 4.9). These proteins had high sequence identities to each other and to PAGs purified from other species. Each had two putative N-glycosylation sites within the 27 amino terminal residues sequenced. This work demonstrates that PAGs are present in goat placenta and that multiple forms are expressed. [less ▲]

Side effects of repeated treatments with exogeneous gonadotropins in cattle, sheep and goats

(1997, September 13)

Presented in this paper are investigations on a possible side effect of repeated treatments with exogeneous gonadotropins in cattle, sheep and goats. First is given an historical approach of the discovery ... [more ▼]

Presented in this paper are investigations on a possible side effect of repeated treatments with exogeneous gonadotropins in cattle, sheep and goats. First is given an historical approach of the discovery of human and equine chorionic gonadotropins including their biochemical properties. This review is continued with a brief report of some basic notions concerning the immune system followed by the description of respective sensitivities of different species to repeated gonadotropic treatments. A summarized presentation of the results of our investigations and those of different authors on circulating antibodies against exogeneous gonadotropins in the same species is then proposed. A synthetic reflexion leads to point out the positive influence of the philogenetic distance between the species - source of the gonadotropins (human or equine)- and the treated species -human, bovine, caprine, ovine- on the intensity of the immune reaction. [less ▲]

Absence of relation between the production of anti-PMSG antibodies and the receptivity or productivity of rabbit does

(1997, September 12)

Le clonage par transfert de noyau dans l'espèce bovine

in Annales de Médecine Vétérinaire (1997), 141

A all in vitro cloning technique was developed in wich embryos from the first cycle nuclear transfer (cloning) were used as blastomere donor for the second cycle nuclear transfer (re-cloning). Such method ... [more ▼]

A all in vitro cloning technique was developed in wich embryos from the first cycle nuclear transfer (cloning) were used as blastomere donor for the second cycle nuclear transfer (re-cloning). Such method permitted to produce 14,5% of morulae and 14,9% of blastocysts after the first and second cycle of nuclear transfer, respectively. The rates of birth obtained after transfer of such embryos were 21,4% and 20,5% for first and second cyle respectively, corresponding to 6 and 5 calves for 28 and 24 transferred embryos. Unfortunately, gestation patholgies and an increase of birth weights were observed. It seems that the in vitro presence of gametes and/or embryos may be responsible of an alteration in the control of gene expression. [less ▲]

Interests of pregnancy follow-up in cows after embryo transfer : special focusing on IVP & NT

(1996, September 13)

In this report, pregnancies were obtained after extreme in vitro conditions- IVM/F/C of the donor embryos, - IVM, enucleation and artificial activation of the recipient oocytes, - nuclear transfer and ... [more ▼]

In this report, pregnancies were obtained after extreme in vitro conditions- IVM/F/C of the donor embryos, - IVM, enucleation and artificial activation of the recipient oocytes, - nuclear transfer and - IVC of the reconstituted embryos. Even if the incidence of this syndrome is relatively low after embryo transfer, a possible increasing of its occurence cannot be excluded in correlation with an incomplete maturation of oocytes at the time of fertilization, smaller follicles giving non competent or partially competent oocytes. An other explanation of this syndrome resulting in the higher variation in newborn calves weight may be also partly explained by the in vitro conditions. The gametes and/or embryos may be submitted to media containing embryotoxic substances. In the other hand, gametes and/or embryos may not found embryotrophic substances in the media like growth factors... Owing to this phenomenon, strict recommendations should be followed concerning rigorous follow-up of pregnancies obtained after transfer of IVM/IVF/IVC or cloned embryos by pregnancy proteins (PSPB, PAG...) or hormone (placental lactogen, estrone sulfate) assay and, after birth, macroscopic examinations of newborn, cord and caroncules. [less ▲]

Viability of cloned bovine embryos after one or two cycles of nuclear transfer and in vitro culture

in Theriogenology (1995), 44

We described an exclusively in vitro procedure for cloning and recloning bovine embryos. Embryos obtained by IVM/IVF/IVC developed to the morula stage were used as blastomere donors in cunjunction with ... [more ▼]

We described an exclusively in vitro procedure for cloning and recloning bovine embryos. Embryos obtained by IVM/IVF/IVC developed to the morula stage were used as blastomere donors in cunjunction with IVM recipient oocytes. Reconstructed embryos were developed in vitro in co-culture using bovine oviductal epithelial cells. The resulting morulae were used as donors for recloning under the same experimental conditions. No significant difference was observed between cloning and recloning in terms of development (rates of blastocysts: 12.9 versus 14.9%), in the number of nuclei per blastocyst (63.8 versus 49.1), or in pregnancy rates (35.7 versus 33.3%). The high variability observed between replicates and the correlation between results in first and second cycle nuclear transfer may suggest an inherant potential of individual donor embryos to support development by cloning [less ▲]