References of "Beckers, Jean-François"
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See detailFractionation and partial characterization of proteins extracted from the bovine fallopian tube: preparation of tools for further purifications
Remy, Benoît ULg; Rabahi, F.; Duwez, L. et al

in Theriogenology (1995), 44(1), 95-107

Described in the present paper is a combined biochemical and immunological approach to study oviductal proteins in the bovine. Antisera were raised against semi-purified proteins extracted from bovine ... [more ▼]

Described in the present paper is a combined biochemical and immunological approach to study oviductal proteins in the bovine. Antisera were raised against semi-purified proteins extracted from bovine tubal mucosal tissue and were characterized. These antisera are available to monitor puritications of specific oviductal proteins in the future. Oviducts from 170 cyclic cows were collected at a slaughterhouse, and high amounts of mucosal proteins were extracted. The proteins were fractionated after precipitation with ammonium sulfate, anti-bovine serum albumin (bSA) and anti-bovine immunoglobulins bIg) afiinity chromatography and ion exchange chromatography. Each of the 12 fractions obtained after ion exchange chromatography was used to immunize a rabbit. Conditioned media were recovered from bovine oviduct cell monolayers cultured without serum to cot&m the oviductal origin of the extracted proteins. After Western blot analysis, 15 proteins were detected in the bovine oviductal extracts, and their molecular weights and isoelectric points were determined by 2 dimensional electrophoresis. Among these 15 proteins, 11 were also detected in conditioned media of bovine oviductal cells. These results demonstrate an oviductal origin of the 11 detected proteins and strongly suggest their secretion by the oviductal cells. [less ▲]

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See detailThe gene encoding bovine pregnancy-associated glycoprotein-1, an inactive member of the aspartic proteinase family
Xie, S.; Green, J.; Beckers, Jean-François ULg et al

in Gene (1995), 159(2), 193-197

Bovine pregnancy-associated glycoprotein 1 (bPAG1) is a member of the aspartic proteinase family. It becomes detectable in maternal serum soon after implantation and is produced specifically in the ... [more ▼]

Bovine pregnancy-associated glycoprotein 1 (bPAG1) is a member of the aspartic proteinase family. It becomes detectable in maternal serum soon after implantation and is produced specifically in the invasive binucleate cells of the placenta. As a result of a key mutation within its catalytic center, bPAG1 appears to be proteolytically inactive. Its gene consists of nine exons (size range 99-281 bp) and eight introns (87-1800 bp) organized in a manner very similar to those of proteolytically active mammalian aspartic proteinases. The transcription start point (tsp) is located 53 or 54 bp upstream from the start codon (ATG) and 19 bp downstream from a 5'-TATATAA sequence. Southern blot analyses have indicated the presence of two bPAG1 genes. By screening with an antiserum raised against bPAG1, a less common cDNA with 91% sequence identity to the bPAG1 transcript has been isolated from a placental cDNA library and presumably represents the second gene. At least eight other genes with sequences that hybridize relatively weakly to the bPAG1 probe are present in the bovine genome. Despite the similarities in the transcribed portion of the genes encoding PAG1, pepsinogen and other mammalian aspartic proteinases, the sequences upstream from the tsp of bPAG1 are unique. [less ▲]

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See detailEffects of fetal bovine serum, FSH and 17ß-Estradiol on the culture of bovine preantral follicles
Hulshof, S. C. J.; Figueiredo, J. R.; Beckers, Jean-François ULg et al

in Theriogenology (1995), 44(2), 217-226

We describe a 7-d culture in droplets of collagen gel of isolated small bovine preantral follicles in medium with or without 10% fetal bovine serum (FBS). In addition, the effect of human recombinant FSH ... [more ▼]

We describe a 7-d culture in droplets of collagen gel of isolated small bovine preantral follicles in medium with or without 10% fetal bovine serum (FBS). In addition, the effect of human recombinant FSH and 17beta-estradiol on the morphology and growth of the preantral follicles was investigated in medium without FBS. After culture in medium with 10% FBS, the increase in follicle diameter was 13.1 +/- 8.4 microm, the percentage of BrdU-labeled cells was 49.9 +/- 11.3 and the number of cells per area granulosa was 11.1 +/- 1.8. Omission of serum from the culture medium had no effect on the percentage of labeled cells, but the diameter increase was lower and the cells were smaller. Apparently, serum affects the size of the granulosa cells from small preantral follicles rather than the stimulation of cell proliferation. Addition of human recombinant FSH and/or 17beta-estradiol to serum-free medium resulted in a larger diameter increase during culture compared with that of the control. With FSH, this was due to an increase in cell proliferation, while with estradiol this was caused by an increase in granulosa cell size. The effects of simultaneous treatment with FSH and estradiol was simply the combination of their individual effects. In conclusion, small bovine preantral follicles can be cultured for 7 d in the absence of serum and hormones. The follicles increase in diameter and react to FSH with enhanced cell proliferation and to estradiol with an increase in cell size. [less ▲]

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See detailIsolement et caractérisation partielle d'une glycoprotéine associée à la gestation chez la brebis
Zoli, A. P.; Beckers, Jean-François ULg; Ectors, Francis ULg

in Annales de Médecine Vétérinaire (1995), 139

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See detailSuperovulation of goats with purified pFSH supplemented with defined amounts of pLH
Nowshari, M. A.; Beckers, Jean-François ULg; Holtz, W.

in Theriogenology (1995), 43

The superovulatory response of goats treated with purified pFSH supplemented with 30, 40 or 50% pLH was compared. Sixty-four Boer goat does were synchronized by progestagen-containing ear implant ... [more ▼]

The superovulatory response of goats treated with purified pFSH supplemented with 30, 40 or 50% pLH was compared. Sixty-four Boer goat does were synchronized by progestagen-containing ear implant, randomly allotted to 3 groups and, beginning 2 d before implant removal, treated with purified pFSH supplemented with 30, 40 or 50% pLH. Each animal received 16 Armour Units of pFSH administered in 6 descending doses at 12-h intervals. Along with the last 2 injections, the does received 5 mg PGF(2alpha). Embryos were flushed either surgically or after slaughter on Day 5 or 6 after the last day of standing estrus. The percentage of animals responding to treatment was not different among groups treated with pFSH supplemented with 30, 40 or 50% pLH (76, 71 and 63%, respectively). The corresponding data for number of ovulations was 11.3 +/- 1.6, 16.3 +/- 1.8 and 16.4 +/- 2.6, for number of ova and embryos recovered 8.1 +/- 1.9, 12.0 +/- 1.5 and 13.5 +/- 2.9 and for number of transferable embryos 6.6 +/- 1.9, 9.1 +/- 1.5 and 7.1 +/- 2.1 (x +/- SEM). Results confirm the earlier finding of a good response of goats to pFSH preparations with a high FSH:LH ratio, and, although group differences were statistically nonsignificant (P > 0.05), they suggest that supplementation with approximately 40% pLH may be close to the optimum [less ▲]

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See detailViability of cloned bovine embryos after one or two cycles of nuclear transfer and in vitro culture
Ectors, Fabien ULg; Delval, Alain; Smith, Lawrence et al

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 ▲]

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See detailExtracellular matrix proteins and basement membrane identification in bovine ovaries and significance for the attachment of cultured preantral follicles
Figueiredo, J. R.; Hulshof, S. C. J.; Thiry, Marc ULg et al

in Theriogenology (1995), 43(5), 845-858

Described in the present paper is the immunolocalization of the extracellular matrix proteins (e.g., fibronectin, collagen Types I and III) in the bovine ovary, with special attention to preantral ... [more ▼]

Described in the present paper is the immunolocalization of the extracellular matrix proteins (e.g., fibronectin, collagen Types I and III) in the bovine ovary, with special attention to preantral follicles. In addition, we have shown, histochemically and ultrastructurally, that mechanically isolated bovine preantral follicles are surrounded by an intact basement membrane. After 24 h of culture in serum-free medium, only 20.4% of these follicles attached to a plastic substrate. We showed that covering the plastic with extracellular matrix proteins (i.e., fibronectin, collagen Type I and matrigel) significantly increased the percentage of attached follicles to 76.0, 65.2 and 80.4%, respectively, while laminin had no effect (18.6%). When preantral follicles were embedded within three-dimensional collagen gels, no loss of follicles was observed. Restoring surface interactions between preantral follicles and the extracellular matrix in vitro, either in a two- or a three-dimensional system, might be important for maintaining follicular viability and growth in the future. [less ▲]

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See detailSuperovulation in cows with FSH preparation containing different amounts of LH
Smorag, Z.; Beckers, Jean-François ULg; Bychawski, S. et al

in Roczniki Naukowe Zootechniki (1995), 22(2), 103-108

One of the main factors influencing the effectiveness of superovulation is the quality of gonadotropin used.Especially the proportion of FSH to Lh can play an important role.In the experiment ... [more ▼]

One of the main factors influencing the effectiveness of superovulation is the quality of gonadotropin used.Especially the proportion of FSH to Lh can play an important role.In the experiment superovulatory response of cows treated with FSH containing different amounts of LH was evaluated.Observations were carried out on 120 Polish Black-and-White Lowland cows aged from 5 to 8 years.On day 9, 10 and 11 after oestrus, 40 mg of FSH containing 10,20 or 40% of LH was injected in 8 decreasing doses at 12 h intervals.In the control group 3000 IU PMSG per cow was administrated.Forty-eight hours after the initial FSH or PMSG injection, 3 ml PGF 2-alpha analog was injected to donors to induce oestrus.An average of 5.6, 5.3, 3.9 and 1.7 transferable embryos was recovered after treatment of the cows with FSH +20% LH, FSH +40% LH, FSH +10% LH and PSMG, respectively. [less ▲]

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See detailEvaluation of cryopreservation techniques for goat embryos
Fiéni, F.; Beckers, Jean-François ULg; Buggin, M. et al

in Reproduction Nutrition Development (1995), 35

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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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