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Peer Reviewed
See detailIn vitro modulation of keratinocyte attachment by minocycline HCl.
Van Heusden, Alain ULg; Rompen, Eric ULg; Lebfevre, P. et al

Poster (1994)

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See detailIn vitro modulation of keratinocyte attachment to dentin by minocycline
Van Heusden, Alain ULg; Rompen, Eric ULg; Lapière, Charles

in Journal of Dental Research (1997), 76

Detailed reference viewed: 16 (3 ULg)
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See detailIn vitro modulation of radiosenitizing effect of FMdC. The importance of simultaneous alteration of the novo and salvage pathways to deoxyribonucleosides.
COUCKE, Philippe ULg; Cottin, E; Ciernick, I-F et al

in International Journal of Radiation, Oncology, Biology, Physics (2000), 46(3),

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See detailIn vitro multiplication of an industrial fiber plant: kenaf (Hibiscus cannabinus L.)
Arbaoui, Sarra; Campanella, Bruno ULg; Paul, Roger ULg et al

Poster (2012, April 23)

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See detailIn vitro neuroblastoma cell infection by varicella-zoster virus
Bourdon-Wouters, C.; Merville, Marie-Paule ULg; Piette, Jacques ULg et al

Poster (1988)

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See detailIN VITRO NUCLEAR AND CYTOPLASMIC MATURATION OF THE EQUINE OOCYTE: INFLUENCE OF CYSTEAMINE
Deleuze, Stefan ULg

Doctoral thesis (2009)

Research on in vitro embryo production (IVP) in the equine is impeded by the limited availability of mature oocytes as the mare is mono ovulating and superovulation is still difficult (Dippert and Squires ... [more ▼]

Research on in vitro embryo production (IVP) in the equine is impeded by the limited availability of mature oocytes as the mare is mono ovulating and superovulation is still difficult (Dippert and Squires, 1994; Bezard et al., 1995; Alvarenga et al., 2001b). Despite recent improvement in IVM of equine oocytes, success rates of IVM in that species remain low in all culture media tested compared to other species (Goudet et al., 2000b). However, most studies have focused on the percentage of oocytes reaching the metaphase II stage (nuclear maturation) but few concentrated on the final oocyte competence as measured by its ability to develop into a blastocyst and further establish a pregnancy. Blastocyst production rate is influenced not only by culture environment but also by oocyte maturation conditions. Under in vitro culture conditions, oxidative modifications of cell components via increased ROS represent a major culture induced stress (Johnson and Nasr-Esfahani, 1994). Anti-oxidant systems can attenuate the deleterious effects of oxidative stress by scavenging ROS (Del Corso et al., 1994). Glutathione, a tripeptide thiol, is the major non-protein sulfydryl compound in mammalian cells that plays an important role in protecting the cell from oxidative damage (Meister and Tate, 1976; Meister and Anderson, 1983). It has been suggested that GSH content in oocytes may serve as a reservoir protecting the zygote and the early embryos from oxidative damage before genomic activation and de novo GSH synthesis occur (Furnus et al., 1998; de Matos and Furnus, 2000). The addition of GSH synthesis precursors, such as cysteamine, a thiol compound, to IVM media has been shown to improve IVP in various species (Takahashi et al., 1993; de Matos et al., 1995; Grupen et al., 1995; de Matos et al., 2002a; de Matos et al., 2002b; de Matos et al., 2003; Gasparrini et al., 2003; Oyamada and Fukui, 2004; Balasubramanian and Rho, 2007; Anand et al., 2008; Singhal et al., 2008; Zhou et al., 2008). Very little information on the use of thiol compounds in the equine is available. Conventional in vitro fertilization (IVF) has not been successful in the mare, and a repeatable IVF technique has not yet been developed (Alm et al., 2001). To overcome the limitation of conventional IVF procedures, other methods to produce embryos from oocytes, either in vivo or in vitro, have been investigated. Among these, intra cytoplasmic sperm injection (ICSI) has permitted efficient equine in vitro blastocyst production (Galli et al., 2002; Lazzari et al., 2002; Choi et al., 2006a; Choi et al., 2006c). However, ICSI requires specific equipment and skills. Transfer of an immature oocyte into the preovulatory follicle of an inseminated recipient mare (Intra-Follicular Oocyte Transfer, IFOT) has produced embryos but the success rate was low (Hinrichs and Digiorgio, 1991). Similarly, oocyte transfer (OT) into the oviduct of an inseminated recipient mare was investigated (McKinnon et al., 1988; Carnevale, 1996; Hinrichs et al., 1997; Carnevale et al., 2001; Carnevale et al., 2003; Carnevale, 2004), and commercial programs using OT for mares with reproductive abnormalities are now available (Carnevale et al., 2001). Unfortunately, IFOT is poorly documented in the literature and reports of OT have been published by various laboratories and under various conditions, making comparisons between results and choosing among these as substitutive techniques to ICSI or embryo transfer difficult. The first aim of the present work was to investigate if there is an influence of supplementation with 100 µM of cysteamine on conventional IVF success rate. Cumulus oocytes complexes (COCs) retrieved by transvaginal ultrasound guided aspiration were matured in vitro with or without cysteamine supplementation and were then submitted to conventional IVF using either calcium ionophore or heparin as capacitation treatment for spermatozoa. A total of 131 oocytes were evaluated for evidence of sperm penetration. Both techniques (ionophore or heparin) yielded 6% of IVF and results were similar both for the cysteamine and the control group. This success rate of IVF is low compared to some published data (Palmer et al., 1991; Dell'Aquila et al., 1996; McPartlin et al., 2009) but similar to what others reported in the literature (Choi et al., 1994; Dell'Aquila et al., 1997a). Although, it seems likely that cysteamine did not significantly improve IVF rates under our conditions, our general success rates for IVF procedures may be too low for us to conclude definitely about the effect of cysteamine. As ICSI was not available to us, the second aim of this work was to determine what in vivo technique could best bypass the lack of an efficient conventional IVF procedure. We compared embryo production following transfer of in vivo recovered oocytes (1) into a recipient’s oviduct or (2) into her preovulatory follicle either immediately after ovum pick up or (3) after in vitro maturation. Recipients were inseminated with fresh semen of a stallion with a known normal fertility. Ten days after transfer, rates of embryos collected in excess to the number of ovulations were calculated and compared for each group. Embryo collection rates were 32.5% (13/40), 5.5% (3/55) and 12.8% (6/47) for OT, post-IVM and immediate IFOT respectively. OT significantly yielded more embryos than immediate and post-IVM IFOT did. These results show that, when ICSI is not an option, intra-oviductal oocyte transfer is to be preferred to IFOT, as an in vivo alternative, to bypass the inadequacy of conventional in vitro fertilization and to assess oocyte developmental competence. After it was established that in comparison to IFOT, OT is the most reliable in vivo alternative to in vitro fertilization where ICSI technology is not available, this technique was used to assess the effect of cysteamine supplementation on nuclear maturation and oocyte competence. The third aim of this work was to investigate the influence of supplementation with 100 µM of cysteamine on in vitro nuclear and cytoplasmic maturation by specific DNA staining and the ability of oocytes to undergo in vivo fertilization after OT. Oocytes were collected by transvaginal ultrasound guided aspiration and matured in vitro with (cysteamine group) or without (control group) cysteamine. The nuclear stage after DNA Hoechst staining and the embryo yield following OT were used as a criterion for assessing nuclear and cytoplasmic maturation, respectively. Overall maturation rate was 52%, which is rates reported in the literature ranging from 40 to 70% in the equine (Goudet et al., 1997a; Bogh et al., 2002; Hinrichs et al., 2005; Galli et al., 2007). Nuclear maturation was not statistically different (p>0.05) between oocytes cultured with or without cysteamine (55% and 47% respectively). From 57 oocytes transferred to the oviduct in each group, the number of embryos collected was 10 (17%) in the control group and 5 in the cysteamine group (9%). Those two percentages were not statistically different (p>0.05). Contrary to the data described in other domestic species, there was no effect of cysteamine on in vitro nuclear maturation, or in vivo embryonic development under our conditions. Under our conditions, the addition of 100 µM of cysteamine to a classic culture medium does not improve equine oocyte maturation or embryonic development after OT. The same dose failed to increase GSH content in the equine (Luciano et al., 2006). However, the effect of cysteamine supplementation is highly species and concentration dependant. The inadequacy of the chosen concentration may explain that equine embryo production has not been increased by the cysteamine under our conditions as opposed to what has been observed in many other species. Alternatively, we can hypothesize that some substances present in the IVM medium can interfere with GSH synthesis. This has been suggested for FSH and estradiol (Bing et al., 2001) and, although our maturation medium is not supplemented with gonadotropins or estradiol, factors contained in fetal calf serum or EGF might also have an effect on GSH synthesis. Considering its beneficial effects in many other species, supplementation with cysteamine to different IVM media should be further investigated in the equine. Ideally combining different concentrations and ICSI or OT in order to determine an optimal concentration and its effects on oocyte developmental competence. [less ▲]

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See detailIn vitro oocyte IGF-I priming increases inner cell mass proliferation of in vitro-formed bovine blastocysts
Velazquez, MA; Hadeler, KG; Herrmann, D et al

in Theriogenology (2012), 78(3), 517-527

Studies addressing the effects of supraphysiological levels of IGF-1 on oocyte developmental competence are relevant for unravelling conditions resulting in high bioavailability of IGF-1, such as the ... [more ▼]

Studies addressing the effects of supraphysiological levels of IGF-1 on oocyte developmental competence are relevant for unravelling conditions resulting in high bioavailability of IGF-1, such as the polycystic ovary syndrome (PCOS). This study investigated the effects of supraphysiological levels of IGF-1 during in vivo folliculogenesis on the morula-blastocyst transition in bovine embryos. Compacted morulae were non-surgically collected and frozen for subsequent mRNA expression analysis (IGF1R, IGBP3, TP53, AKT1, SLC2A1, SLC2A3, and SLC2A8), or underwent confocalmicroscopy analysis for protein localization (IGF1R and TP53), or were cultured in vitro for 24 h. In vitro-formed blastocysts were subjected to differential cell staining. The mRNA expression of SLC2A8 was higher in morulae collected from cows treated with IGF-1. Both IGF1R and TP53 protein were present in the plasma membrane and cytoplasm. IGF-1 treatment did not affect protein localization of both IGF1R and TP53. In vitro-formed blastocysts derived from morulae recovered from IGF-1-treated cows displayed a higher number of cells in the inner cell mass (ICM). Total cell number (TCN) of in vitro-formed blastocysts was not affected. A higher mean ICM/TCN proportion was observed in in vitro-formed blastocysts derived from morulae collected from cows treated with IGF-1. The percentage of in vitro-formed blastocysts displaying a low ICM/TCN proportion was decreased by IGF-1 treatment. In vitro-formed blastocysts with a high ICM/TCN proportion were only detected in IGF-1 treated cows. Results show that even a short in vivo exposure of oocytes to a supraphysiological IGF-1 microenvironment can increase ICM cell proliferation in vitro during the morula to blastocyst transition [less ▲]

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See detailIn vitro ototoxicity of aminoglycosides and platin derivatives. A semi-automatic assay for sensory hair cell damage in explanted rat organ of corti.
Malgrange, B.; LEFEBVRE, Philippe ULg; van de Water, T.R. et al

in Toxicology in Vitro (1998), 12 (6)

The ototoxic damage that drugs such as neomycin, kanamycin, colistin, cisplatin, transplatin and carboplatin cause on outer and inner hair cells in postnatal day 3 rat cochlear explants was investigated ... [more ▼]

The ototoxic damage that drugs such as neomycin, kanamycin, colistin, cisplatin, transplatin and carboplatin cause on outer and inner hair cells in postnatal day 3 rat cochlear explants was investigated. Phalloidin-fluorescein conjugate-stained stereocilia bundles of sensory hair cells were quantified by video image analysis as a measurement of ototoxic effect. The video image quantification system established dose-response curves for ototoxic drugs (e.g. calculation of an IC50) and allowed comparisons between several ototoxins from the same family. This methodology provided the means to assess the efficacy of otoprotectant agents in preventing ototoxicity. Poly-l-aspartate (10-5M) and poly-l-glutamate (10-5M) protected auditory hair cells from neomycin (10-3M) toxicity while reduced glutathione (10-3M) provided protection against cisplatin (10-4M)-induced hair cell damage. [less ▲]

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See detailIn vitro paradigms for the study of GnRH neuron function and estrogen effects.
Matagne, Valerie; LEBRETHON, Marie-Christine ULg; Gerard, Arlette et al

in Annals of the New York Academy of Sciences (2003), 1007

The elaboration of in vitro paradigms has enabled direct study of GnRH secretion and the regulation of this process. Common findings using different models are the pulsatile nature and calcium-dependency ... [more ▼]

The elaboration of in vitro paradigms has enabled direct study of GnRH secretion and the regulation of this process. Common findings using different models are the pulsatile nature and calcium-dependency of GnRH secretion, the excitatory effect of glutamate, and the inhibitory or excitatory effect of GABA. Among the different paradigms, the fetal olfactory placode cultures exhibit the unique property of migration in vitro and may retain the capacity to undergo maturational changes in vitro. The short-term incubation of hypothalamic explants obtained at different ages enables one to study developmental changes as well. Estrogens may have important roles in the regulation of GnRH function and can act indirectly via the neighboring neuronal/glial apparatus and directly on GnRH neurons at the cell body and terminal levels. A direct effect is supported by the recent localization of ERalpha and ERbeta transcripts in GnRH neurons using most paradigms. Discrepant effects of estrogens on GnRH neurons were observed since GnRH biosynthesis is inhibited while GnRH secretion can be either stimulated, unaffected, or reduced. It is likely that the regulatory role of sex steroids including estradiol is very complex since it could involve direct and indirect effects on GnRH neurons through genomic and/or non-genomic mechanisms. [less ▲]

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See detailIn vitro pharmacological activity of salbutamol acetonide on the isolated guinea-pig trachea and porcine bronchus
Leemans, Jérôme ULg; Kirschvink, Nathalie; Delvaux, F. et al

in Fundamental & Clinical Pharmacology (2005), 19

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See detailIn vitro pre-digestion to estimate fermentability of feedstuffs in pig large intestine
Boudry, Christelle ULg; Estrada, Fernando; Schoeling, Olivia et al

in Ball, Ronald O. (Ed.) Proceedings of the 9th International Symposium on Digestive Physiology in Pigs (2003, May)

The aim of this study was to compare ileal and faecal digestibilities to gas production in syringes, preceded or not by an in vitro enzymatic digestion of two pig diets containing different amounts of non ... [more ▼]

The aim of this study was to compare ileal and faecal digestibilities to gas production in syringes, preceded or not by an in vitro enzymatic digestion of two pig diets containing different amounts of non starch polysaccharides (NSP). In vivo, only nitrogen faecal digestibility differed between the two diets. Their enzymatic pre-digestion led to a higher gas production after 16 h of incubation in syringes for the diet with the lowest N faecel digestibility but not without pre-digestion. We may conclude that an in vitro pre-digestion before incubation in syringes is necessary to evaluate feed fermentescibility in pig large intestine. [less ▲]

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See detailIn Vitro Preservation of Yam ( Dioscorea cayenensis-D.rotundata complex) for a Better Use of Genetic Resources
Ondo Ovono, Paul ULg; Kevers, Claire ULg; Dommes, Jacques ULg

in Notulae Botanicae Horti Agrobotanici Cluj-Napoca (2010), 38

Among the food crops, yam takes up quantitatively the first place in the gabonese diet. Unfortunately, it can stay available only 6 to 7 months in the year because of difficulties of harvest and post ... [more ▼]

Among the food crops, yam takes up quantitatively the first place in the gabonese diet. Unfortunately, it can stay available only 6 to 7 months in the year because of difficulties of harvest and post- harvest. This problem is little studied in the case of Dioscorea cayenensis-D. rotundata complex. In order to optimize the use of micro tubers for the growing in green house or field, it is important to control the duration of storage before the germination. The present study concerns microtubers obtained by in vitro culture. When microtubers were harvested (after 9 months of culture) and directly transferred on a new medium without hormone, the tubers rapidly sprouted in in vitro conditions. Harvested microtubers were also stored dry in jars in sterile conditions during 2 to 18 weeks before in vitro sprouting. In this case, microtubers stored during 18 weeks sprouted more rapidly than those stored 8 weeks. The size of the tubers used for the storage had great influence on further sprouting. The upper microtubers in 25 mm can be kept to the darkness, under 50% of relative humidity, in 25°C during at least 18 weeks. Sprouting is 100% whatever the substrate of culture. The plant tissue culture technique constitutes a serious alternative for the preservation of plant kinds and for the production of planting material. These techniques allow multiplying in a short time of thousands of copies of new varieties of newly created plants. These in vitro plants can be used on one hand, for the production planting material, and on the other hand for ex vitro storage of breeding grounds with decelerated growth, to struggle against genetic erosion. These results should allow improving in practice the multiplication of yam, while guaranteeing phytosanitary qualities. [less ▲]

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See detailIn vitro production of adaline and coccinelline, two defensive alkaloids from ladybird beetles (Coleoptera : Coccinellidae)
Laurent, Pascal ULg; Braekman, Jean-Claude; Daloze, Désiré et al

in Insect Biochemistry and Molecular Biology (2002), 32(9), 1017-1023

In vitro experiments using [1-C-14] and [2-C-14] acetate were devised to study the biosynthesis of the defensive coccinellid alkaloids adaline and coccinelline in Adalia 2-punctata and Coccinella 7 ... [more ▼]

In vitro experiments using [1-C-14] and [2-C-14] acetate were devised to study the biosynthesis of the defensive coccinellid alkaloids adaline and coccinelline in Adalia 2-punctata and Coccinella 7-punctata, respectively. The labelled alkaloids obtained in these experiments had a specific activity about ten times higher than that of the samples obtained in feeding experiments. This in vitro assay has enabled us to demonstrate that these two alkaloids are most likely biosynthesised through a fatty acid rather than a polyketide pathway, that glutamine is the preferred source of the nitrogen atom and that alkaloid biosynthesis takes place in the insect fat body. [less ▲]

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See detailIn vitro promotion of root formation by apple shoots through darkness effect on endogenous phenols and peroxidases.
Druart, P.; Kevers, Claire ULg; Boxus, P. et al

in Zeitschrift fur Pflanzenphysiologie (1982), 108(5),

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See detailIn Vitro Propagated Dendritic Cells from Patients with Human-Papilloma Virus-Associated Preneoplastic Lesions of the Uterine Cervix: Use of Flt3 Ligand
Hubert, Pascale ULg; Greimers, Roland ULg; Franzen-Detrooz, E. et al

in Cancer Immunology, Immunotherapy (1998), 47(2), 81-9

Dendritic cells (DC) are the most efficient antigen presenting cells. The clinical use of DC as vectors for antitumor and anti-infectious disease immunotherapy has been limited by their low level and ... [more ▼]

Dendritic cells (DC) are the most efficient antigen presenting cells. The clinical use of DC as vectors for antitumor and anti-infectious disease immunotherapy has been limited by their low level and accessibility in normal tissue. Substantial numbers of DC can be generated from peripheral blood cultured in the presence of interleukin-4 (IL-4) and granulocyte/macrophage-colony-stimulating factor (GM-CSF). We showed in this study that substantial numbers of DC can be obtained from the peripheral blood of patients with (pre)neoplastic lesions of the uterine cervix. The procedure required relatively small blood samples (10 ml) and the presence of 100 U/ml IL-4 and 800 U/ml GM-CSF in the culture medium. There was no significant difference in the morphology, yield, phenotype and function of generated DC between patients with cervical (pre)neoplastic lesions and healthy individuals. When the hematopoietic factor Flt3 ligand (Flt3L, 40 ng;ml) was added, there was an average increase in the DC population of 26% compared to cultures with GM-CSF and IL-4 alone. Approximately 1.2 x 10(6) cells with the characteristics of dendritic cells could be obtained when Flt3L was included in the medium. The addition of Flt3L did not modify the phenotypic profile of DC (HLA-DR+, CD1a+, CD4+, CD54+, CD80+, CD86+. CD40+, CD3- and CD14-). In addition, Flt3L generated functional DC capable of stimulating the proliferation of alloreactive T cells. These results suggest that Flt3L, in association with GM-CSF and IL-4, provides an advantageous tool for the large-scale generation of DC and that an immunotherapy based on the use of DC generated in vitro is possible in patients with (pre)neoplastic lesions of the uterine cervix. [less ▲]

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See detailIn vitro reconstruction of epidermis from primary Darier's disease keratinocytes replicates the histopathological phenotype
LAMBERT DE ROUVROIT, CATHERINE; CHARLIER, CELINE; LEDERER, DAMIEN et al

in Journal of Dermatological Science (2013)

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See detailIn vitro recovery of ATP-sensitive potassium channels in Beta-cells from patients with hyperinsulinism in infancy; effects of low temperature and BPDZ 154
Cosgrove, K. E.; Gonzalez, A. M.; Lee, A. T. et al

in Journal of Physiology (2002), 544

Detailed reference viewed: 27 (16 ULg)