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See detailCytokinin promotes flowering of Arabidopsis via transcriptional activation of the FT paralogue TSF
D'Aloia, Maria ULg; Bonhomme, Delphine ULg; Bouché, Frédéric ULg et al

in Plant Journal (The) (2011), 65

Cytokinins are involved in many aspects of plant growth and development and physiological evidence also indicates that they have a role in floral transition. In order to integrate these phytohormones into ... [more ▼]

Cytokinins are involved in many aspects of plant growth and development and physiological evidence also indicates that they have a role in floral transition. In order to integrate these phytohormones into the current knowledge of genetically defined molecular pathways to flowering, we performed exogenous treatments of adult wild-type and mutant Arabidopsis plants and analysed the expression of candidate genes. We used a hydroponic system that enables synchronous growth and flowering of Arabidopsis and allows precise application of chemicals to the roots for defined periods of time. We show that application of N6-benzylaminopurine (BAP) promotes flowering of plants grown in non-inductive short days. The response to cytokinin treatment does not require FLOWERING LOCUS T (FT) but activates its paralogue TWIN SISTER OF FT (TSF), as well as FD, which encodes a partner protein of TSF, and the downstream gene SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1). Treatment of selected mutants confirmed that TSF and SOC1 are necessary for the flowering response to BAP while the activation cascade might partially act independently of FD. These experiments provide a mechanistic basis for the role of cytokinins in flowering and demonstrate that the redundant genes FT and TSF are differently regulated by distinct floral inducing signals. [less ▲]

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See detailA cytokinin route to flowering in Arabidopsis
Bouché, Frédéric ULg; André, Julie ULg; D'Aloia, Maria ULg et al

Poster (2011, June)

Cytokinins (CKs) are involved in many physiological processes. We observed that the application of N6-benzylaminopurine (BAP) to the roots of hydroponically grown plants of Arabidopsis thaliana promotes ... [more ▼]

Cytokinins (CKs) are involved in many physiological processes. We observed that the application of N6-benzylaminopurine (BAP) to the roots of hydroponically grown plants of Arabidopsis thaliana promotes flowering in non-inductive short days. The response to BAP treatment does no require FLOWERING LOCUS T (FT), but activates its paralogue TWIN SISTER OF FT (TSF), as well as FD and SUPPRESSOR OF OVEREXPRESSION OF CO1 (SOC1) (D'Aloia et al., 2011). We present here complementary data obtained with transgenic plants overexpressing a catalytic CK OXIDASE/DEHYDROGENASE (CKX) in the roots. The high efficiency of BAP in promoting flowering in our experimental system contrasts with the variability that emerges from studies gathered in literature. Many factors, either experimental or inherent to plant material, might explain these discrepancies and we are interested in identifying endogenous regulators that might provide a mechanistic explanation. We are therefore investigating whether the endogenous pathways underlying plant developmental phase changes might regulate the relative contribution of CKs to flowering. [less ▲]

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See detailCytokinins and ethylene stimulate indole alkaloid accumulation in cell suspension cultures of Catharanthus roseus by two distinct mechanisms
Yahia, Abdelouahab; Kevers, Claire ULg; Gaspar, Thomas ULg et al

in Plant Science (1998), 133(1), 9-15

The interactions between cytokinins and ethylene on alkaloid accumulation in a periwinkle cell line have been examined. It was found that (a) either exogenously-applied cytokinins or ethylene (the latter ... [more ▼]

The interactions between cytokinins and ethylene on alkaloid accumulation in a periwinkle cell line have been examined. It was found that (a) either exogenously-applied cytokinins or ethylene (the latter through ethephon degradation) greatly enhanced ajmalicine accumulation in cells subcultured in a 2,4-dichlorophenoxyacetic acid-free medium; (b) the enhancing effect of cytokinin was not mediated by enhancement of endogenous ethylene production contrary to what is found in some plant models, (c) the responses to exogenous cytokinin and ethylene were additive and showed a different pattern of expression. It may be concluded that cytokinin and ethylene can up-regulate the alkaloid production in a periwinkle cells through independent pathways when added exogenously to the cultures. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved. [less ▲]

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See detailCytological and cytochemical analysis of the effects of cis-dichlorodiamino platinum (II) on chick fibroblasts cultivated in vitro.
Heinen, Ernst ULg; Bassleer, R.

in Chemotherapy (1976), 22(3-4), 253-61

Chick embryo fibroblasts cultivated in vitro and treated with cis-dichlorodiamino platinum (II) have been analysed by cytological and cytochemical methods. Morphological alterations (in the nucleoli, in ... [more ▼]

Chick embryo fibroblasts cultivated in vitro and treated with cis-dichlorodiamino platinum (II) have been analysed by cytological and cytochemical methods. Morphological alterations (in the nucleoli, in the chromatin and in the cytoplasm), inhibition of DNA and RNA syntheses and of cell multiplication have been noted. Under some conditions, cells are blocked just before entering into mitosis (G2 block) and can become polyploid. A high degree of cell degeneration has also been observed. [less ▲]

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See detailCytological and ecological complexity in the Early Mesoproterozoic.
Javaux, Emmanuelle ULg; Knoll, A. H.; Walter, M.

Conference (2001, November)

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See detailCytological Comparison of Leaves and Stems of Prunus Avium L. Shoots Cultured on a Solid Medium with Agar or Gelrite
Franck, Thierry ULg; Crevecoeur, Michelle; Wuest, J. et al

in Biotechnic & Histochemistry : Official Publication of the Biological Stain Commission (1998), 73(1), 32-43

An axillary proliferating clone of Prunus avium L. was subcultured every four weeks on solid MS medium with agar as the gelling agent. Vitrification (hyperhydricity) of shoots was induced in one four week ... [more ▼]

An axillary proliferating clone of Prunus avium L. was subcultured every four weeks on solid MS medium with agar as the gelling agent. Vitrification (hyperhydricity) of shoots was induced in one four week cycle with the same medium except that agar was replaced by gelrite. During culture on the vitrifying medium, the water content of the shoots progressively increased with a parallel decrease in chlorophyll content. Cytological differences between the leaves and stems of the vitrified and normal shoots were detected by light and electron (both transmission and scanning) microscopy. Leaves of vitrified shoots were characterized by lower number of chloroplasts in the palisade parenchyma and by a defective cuticle. The stems of vitrified shoots had a less developed and lignifled xylem tissue, lacked sclerenchymatic areas and showed hypertrophy of the cortical parenchyma. More intense vacuolar activity with evaginations of the chloroplast envelope into the vacuole was noted in cells of vitrified leaves. [less ▲]

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See detailCytological diagnosis of endometritis in the mare: a comparative study
Daspet, Sarah-Morgane; Ponthier, Jérôme ULg; Jolly, Sandra ULg et al

in Reproduction in Domestic Animals (2010, September), 45s3

It was concluded that the brush swab was a promising diagnostic tool for use in field conditions.

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See detailCytological effects of culture media conditioned B16 melanoma cells and 3T3 fibroblasts
Coucke, Paul; Siwek, B.; Gillet, Marie-Claire ULg et al

in Anticancer Research (1991), 11(2), 801-804

Cytotoxic soluble fractions (M.W.<1,000) were prepared from media conditioned by mixed cultures of 3T3 fibroblasts and B16 cells. The ultrastructural analyses of cells (B16 or 3T3) treated with these ... [more ▼]

Cytotoxic soluble fractions (M.W.<1,000) were prepared from media conditioned by mixed cultures of 3T3 fibroblasts and B16 cells. The ultrastructural analyses of cells (B16 or 3T3) treated with these fractions revealed in them mitochondria swelling, blebs, broken membranes and dead cells. [less ▲]

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See detailCytonuclear discordance among Southeast Asian black rats (Rattus rattus complex)
Pagès, Marie ULg

in Molecular Ecology (2013)

Black rats are major invasive vertebrate pests with severe ecological, economic and health impacts. Remarkably, their evolutionary history has received little attention and there is no firm agreement on ... [more ▼]

Black rats are major invasive vertebrate pests with severe ecological, economic and health impacts. Remarkably, their evolutionary history has received little attention and there is no firm agreement on how many species should be recognized within the black rat complex. This species complex is native to India and Southeast Asia. According to current taxonomic classification, there are three taxa living in sympatry in several parts of Thailand, Cambodia and Lao People's Democratic Republic, where this study was conducted: two accepted species (Rattus tanezumi, Rattus sakeratensis) and an additional mitochondrial lineage of unclear taxonomic status referred to here as ‘Rattus R3’. We used extensive sampling, morphological data and diverse genetic markers differing in rates of evolution and parental inheritance (two mitochondrial DNA genes, one nuclear gene and eight microsatellite loci) to assess the reproductive isolation of these three taxa. Two close Asian relatives, Rattus argentiventer and Rattus exulans, were also included in the genetic analyses. Genetic analyses revealed discordance between the mitochondrial and nuclear data. Mitochondrial phylogeny studies identified three reciprocally monophyletic clades in the black rat complex. However, studies of the phylogeny of the nuclear exon IRBP and clustering and assignation analyses with eight microsatellites failed to separate R. tanezumi and R3. Morphometric analyses were consistent with nuclear data. The incongruence between mitochondrial and nuclear (and morphological) data rendered R. tanezumi/R3 paraphyletic for mitochondrial lineages with respect to R. sakeratensis. Various evolutionary processes, such as shared ancestral polymorphism and incomplete lineage sorting or hybridization with massive mitochondrial introgression between species, may account for this unusual genetic pattern in mammals. [less ▲]

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See detailCytopathology in Belgium.
Drijkoningen, M.; Bogers, J. P.; Bourgain, C. et al

in Cytopathology : Official Journal of the British Society for Clinical Cytology (2005), 16(2), 100-4

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See detailCytoplasmic and Periplasmic Proteomic Signatures of Exponentially Growing Cells of the Psychrophilic Bacterium Pseudoalteromonas haloplanktis TAC125
Wilmes, B.; Kock, H.; Glagla, S. et al

in Applied and Environmental Microbiology (2011), 77(4), 1276-1283

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See detailCytoplasmic I kappa B alpha increases NF-kappa B-independent transcription through binding to histone deacetylase (HDAC) 1 and HDAC3
Viatour, Patrick ULg; Legrand-Poels, Sylvie; van Lint, Carine et al

in Journal of Biological Chemistry (2003), 278(47), 46541-46548

IkappaBalpha is an inhibitory molecule that sequesters NF-kappaB dimers in the cytoplasm of unstimulated cells. Upon stimulation, NF-kappaB moves to the nucleus and induces the expression of a variety of ... [more ▼]

IkappaBalpha is an inhibitory molecule that sequesters NF-kappaB dimers in the cytoplasm of unstimulated cells. Upon stimulation, NF-kappaB moves to the nucleus and induces the expression of a variety of genes including IkappaBalpha. This newly synthesized IkappaBalpha also translocates to the nucleus, removes activated NF-kappaB from its target genes, and brings it back to the cytoplasm to terminate the phase of NF-kappaB activation. We show here that IkappaBalpha enhances the transactivation potential of several homeodomain-containing proteins such as HOXB7 and Pit-1 through a NF-kappaB-independent association with histone deacetylase (HDAC) 1 and HDAC3 but not with HDAC2, -4, -5, and -6. IkappaBalpha bound both HDAC proteins through its ankyrin repeats, and this interaction was disrupted by p65. Immunofluorescence experiments demonstrated further that IkappaBalpha acts by partially redirecting HDAC3 to the cytoplasm. At the same time, an IkappaBalpha mutant, which lacked a functional nuclear localization sequence, interacted very efficiently with HDAC1 and -3 and intensively enhanced the transactivation potential of Pit-1. Our results support the hypothesis that the NF-kappaB inhibitor IkappaBalpha regulates the transcriptional activity of homeodomain-containing proteins positively through cytoplasmic sequestration of HDAC1 and HDAC3, a mechanism that would assign a new and unexpected role to IkappaBalpha. [less ▲]

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See detailCytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Colorectal Peritoneal Carcinomatosis : Higher Complication Rate for Oxaliplatin Compared to Mitomycin C
Rouers, A.; Laurent, S.; Detroz, Bernard ULg et al

in Acta Chirurgica Belgica (2006), 106

Peritoneal carcinomatosis (PC) from colo-rectal cancer carries a very poor prognosis with a mean and median overall survival times of 6.9 and 5.2 months. It has been proved that a locoregional therapeutic ... [more ▼]

Peritoneal carcinomatosis (PC) from colo-rectal cancer carries a very poor prognosis with a mean and median overall survival times of 6.9 and 5.2 months. It has been proved that a locoregional therapeutic approach of this disease with cytoreduction followed by hyperthermic intraperitoneal chemotherapy (HIPEC) improved survival of these patients. However, this combined treatment presents a high complication rate. Methods : 21 patients with PC of colorectal origin underwent complete cytoreduction followed by HIPEC using Mitomycin-C (13 patients) or oxaliplatin (8 patients) and the open coliseum technique. For each case the medical datas were retrospectively analysed to determine feasibility, morbidity, mortality, survival time and prognostic factors. Results : All patients presented a Sugarbaker’s Peritoneal Cancer index inferior to 15. The mean operating time was 453 minutes. After a median follow-up of 24.9 months, actuarial disease-free survival was 36.6% at 5 years. The median survival time was 34 months. The morbidity rate was 33.3% with a significant higher complication rate in the oxaliplatin group (5/8) than in the Mytomycin-C (MMC) group (2/13). One patient (4.7%) died two months after treatment with MMC (endocarditis). Conclusions : This series confirm positive impact of cytoreduction and HIPEC on PC. We obtained a moderated complications rate thanks to a high degree of selection of the patient. Oxaliplatin scheme is responsible of a higher morbidity than in MMC group. Phase III trial comparing these two drugs is needed. [less ▲]

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See detailCytosine Deaminase Suicide Gene Therapy for Peritoneal Carcinomatosis
Bentires-Alj, M.; Hellin, A. C.; Lechanteur, Chantal ULg et al

in Cancer Gene Therapy (2000), 7(1), 20-6

Gene therapy is a novel therapeutic approach that might soon improve the prognosis of some cancers. We investigated the feasibility of cytosine deaminase (CD) suicide gene therapy in a model of peritoneal ... [more ▼]

Gene therapy is a novel therapeutic approach that might soon improve the prognosis of some cancers. We investigated the feasibility of cytosine deaminase (CD) suicide gene therapy in a model of peritoneal carcinomatosis. DHD/K12 colorectal adenocarcinoma cells transfected in vitro with the CD gene were highly sensitive to 5-fluorocytosine (5-FC), and a bystander effect could also be observed. Treating CD+ cells with 5-FC resulted in apoptosis as detected by terminal deoxynucleotidyltransferase-mediated deoxyuridine triphosphate nick-end labeling. In vitro, several human cell lines derived from ovarian or colorectal carcinomas, as well as the rat glioblastoma 9 L cell line, responded to CD/5-FC and showed a very strong bystander effect. 5-FC treatment of peritoneal carcinomatosis generated in syngeneic BDIX rats by CD-expressing DHD/K12 cells led to a complete and prolonged response and to prolonged survival. Our study thus demonstrated the efficacy of CD suicide gene therapy for the treatment of peritoneal carcinomatosis. [less ▲]

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See detailCytoskeletal genes and idiopathic epilepsies
Lakaye, Bernard ULg; de Nijs, Laurence ULg; Leon, Christine et al

in Schwartzkroin, A. (Ed.) Encyclopedia of Basic Epilepsy Research (2009)

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See detailCytosolic proteins regulate alpha-synuclein dissociation from presynaptic membranes.
Wislet-Gendebien, Sabine ULg; D'Souza, Cheryl; Kawarai, Toshitaka et al

in Journal of Biological Chemistry (2006), 281(43), 32148-55

Intracellular accumulation of insoluble alpha-synuclein in Lewy bodies is a key neuropathological trait of Parkinson disease (PD). Neither the normal function of alpha-synuclein nor the biochemical ... [more ▼]

Intracellular accumulation of insoluble alpha-synuclein in Lewy bodies is a key neuropathological trait of Parkinson disease (PD). Neither the normal function of alpha-synuclein nor the biochemical mechanisms that cause its deposition are understood, although both are likely influenced by the interaction of alpha-synuclein with vesicular membranes, either for a physiological role in vesicular trafficking or as a pathological seeding mechanism that exacerbates the propensity of alpha-synuclein to self-assemble into fibrils. In addition to the alpha-helical form that is peripherally-attached to vesicles, a substantial portion of alpha-synuclein is freely diffusible in the cytoplasm. The mechanisms controlling alpha-synuclein exchange between these compartments are unknown and the possibility that chronic dysregulation of membrane-bound and soluble alpha-synuclein pools may contribute to Lewy body pathology led us to search for cellular factors that can regulate alpha-synuclein membrane interactions. Here we reveal that dissociation of membrane-bound alpha-synuclein is dependent on brain-specific cytosolic proteins and insensitive to calcium or metabolic energy. Two PD-linked mutations (A30P and A53T) significantly increase the cytosol-dependent alpha-synuclein off-rate but have no effect on cytosol-independent dissociation. These results reveal a novel mechanism by which cytosolic brain proteins modulate alpha-synuclein interactions with intracellular membranes. Importantly, our finding that alpha-synuclein dissociation is up-regulated by both familial PD mutations implicates cytosolic cofactors in disease pathogenesis and as molecular targets to influence alpha-synuclein aggregation. [less ▲]

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See detailCytotoxic Activity of Some Triterpenoid Saponins
Quetin-Leclercq, J.; Elias, R.; Balansard, G. et al

in Planta Medica (1992), 58

The present note deals with the cytotoxic activity of purified saponins of hedera helix and of saponins isolated from other plants ( Calendula officinalis, C. arvensis and Sapindus mukurossi with a view ... [more ▼]

The present note deals with the cytotoxic activity of purified saponins of hedera helix and of saponins isolated from other plants ( Calendula officinalis, C. arvensis and Sapindus mukurossi with a view to the detection of possible structure-activity relationships. The most active compounds are the monodesmosides which show some degree of cytotoxicity at concentrations of 10 micrograms/ml and above. Among them, alpha- and beta-hederin are the most potent substances. [less ▲]

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