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See detailCellular Events in Radiation-Induced Lymphomagenesis
Boniver, Jacques ULg; Humblet, Chantal ULg; Rongy, A. M. et al

in International Journal of Radiation Biology (1990), 57(4), 693-8

Fractionated whole-body irradiation induces thymic lymphomas in most of treated C57Bl/Ka mice. The cellular events occurring during the latency period consist of the emergence of preleukaemic cells and of ... [more ▼]

Fractionated whole-body irradiation induces thymic lymphomas in most of treated C57Bl/Ka mice. The cellular events occurring during the latency period consist of the emergence of preleukaemic cells and of marked alterations to the T-cell lineage and the microenvironment within the thymus. The proportions of the various thymocyte subsets are modified, suggesting a blockage in the normal differentiation process. Thymic epithelial cells are functionally modified, leading to decreased interactions with immature thymocytes. Interestingly, bone marrow grafting early after irradiation, which inhibits the development of lymphomas, induces the disappearance of preleukaemic cells from the thymus, whereas thymocyte subpopulations and thymic epithelium are restored. Interferon gamma and tumor necrosis factor alpha also prevent the onset of lymphomas. Studies on the effect of bone marrow transplantation and cytokine inoculation in split-dose irradiated mice should allow characterization of the factors that modulate the progression of preleukaemic cells towards the neoplastic state. [less ▲]

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See detailCellular immunotherapy in multiple myeloma : lessons from preclinical models
Binsfeld, Marilène ULg; Fostier, K.; Muller, Joséphine ULg et al

in Biochimica et Biophysica Acta - Reviews on Cancer (2014), 1846

The majority of multiple myeloma patients relapse with the current treatment strategies, raising the need for alternative therapeutic approaches. Cellular immunotherapy is a rapidly evolving field and ... [more ▼]

The majority of multiple myeloma patients relapse with the current treatment strategies, raising the need for alternative therapeutic approaches. Cellular immunotherapy is a rapidly evolving field and currently being translated into clinical trials with encouraging results in several cancer types, including multiple myeloma. Murine multiple myeloma models are of critical importance for the development and refinement of cellular immunotherapy. In this review,we summarize the immune cell changes that occur inmultiplemyelomapatients and we discuss the cell-based immunotherapies that have been tested in multiple myeloma, with a focus on murine models. [less ▲]

Detailed reference viewed: 42 (7 ULg)
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See detailCellular localization of IGF-I and IGF-II mRNAs in immature hypophysectomized rat testis and epididymis after in vivo hormonal treatment.
Dombrowicz, D.; Hooghe-Peters, E. L.; GOTHOT, André ULg et al

in Archives internationales de physiologie, de biochimie et de biophysique (1992), 100(5), 303-8

IGF-I and II genes expression has been localized by in situ hybridization in testis and epididymis of immature hypophysectomized rats treated in vivo with either pFSH, hLH, bGH, hPRL or with saline. IGF-I ... [more ▼]

IGF-I and II genes expression has been localized by in situ hybridization in testis and epididymis of immature hypophysectomized rats treated in vivo with either pFSH, hLH, bGH, hPRL or with saline. IGF-I mRNA expression was found in both Sertoli and Leydig cells after treatment with either FSH or LH. IGF-I mRNA was highly expressed in germ cells after FSH stimulation and to a lesser extent after GH or LH treatments. However, its expression was very low in hypophysectomized control or PRL treated rats. IGF-I mRNA was also expressed in stromal cells of epididymis after LH treatment and to a lesser extent after GH stimulation. In contrast, IGF-II mRNA expression was detected in all testicular cell types whatever the hormonal treatment (FSH, LH, GH, PRL). For each hormonal treatment testicular sections were examined after immunohistochemical staining with specific antisera against IGF-I and IGF-II. Both in situ hybridization and immunohistochemical data were examined in order to determine the testicular sites of synthesis of IGF-I and IGF-II. [less ▲]

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See detailCellular mechanisms controlling rapid changes in brain aromatase activity
Charlier, Thierry; Cornil, Charlotte ULg; Ball, Gregory et al

in Balthazart, Jacques; Ball, Gregory (Eds.) Brain aromatase, estrogens and behavior (2012)

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See detailCellular Pathways Involved In The Ex Vivo Expression Of Bovine Leukemia Virus
Kerkhofs, P.; Adam, E.; Droogmans, L. et al

in Journal of Virology (1996), 70(4),

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See detailCellular proliferation in villi of normal and pathological pregnancies.
Hustin, J.; Foidart, Jean-Michel ULg; Lambotte, R.

in Gynecologic & Obstetric Investigation (1984), 17(1), 1-9

DNA and protein synthesis have been studied in placental villi from normal and pathological cases by in vitro incorporation of tritiated thymidine or tritiated proline and subsequent counting or ... [more ▼]

DNA and protein synthesis have been studied in placental villi from normal and pathological cases by in vitro incorporation of tritiated thymidine or tritiated proline and subsequent counting or autoradiography. It appeared that cytotrophoblastic DNA synthesis continued until term and that it was particularly important in preeclampsia cases and in cases of villous immaturity (rhesus sensitization). Protein synthesis was also increased in preeclampsia and seemed to be due to a very active cytotrophoblastic metabolism. The most interesting finding was that in preeclampsia cases, especially when intrauterine growth retardation was superimposed, villous capillary endothelial cell proliferation was as prominent as in cases where villous maturation was not achieved. Such results are highly suggestive of an important compensatory proliferative mechanism in the placentae of preeclamptic women. [less ▲]

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See detailCellular regulation mechanisms : case study of up and down states in the Purkinje cell
Wehenkel, Marie ULg

Master's dissertation (2014)

In 1963, Hodgkin and Huxley obtained the Nobel Prize to have shown that the electrical activity of a neuron could be modelled by an electrical RC circuit containing non-linear conductances. This discovery ... [more ▼]

In 1963, Hodgkin and Huxley obtained the Nobel Prize to have shown that the electrical activity of a neuron could be modelled by an electrical RC circuit containing non-linear conductances. This discovery made it possible to reproduce the electrical behaviour of neurons with a level of detail that has steadily increased over the last fifty years as new quantitative knowledge became available about the specific ionic currents that regulate the activity of a given neuron. But models with too many details are often non-robust and too complex for analysis. As control engineers need simplified models for control design, experimental neurophysiologists are in need of models that are amenable to sensitivity and robustness analysis, beyond the mere simulation of a given neuronal behaviour recorded experimentally. The Purkinje cell has been studied for over hundred years because its large dendritic tree enables to recognize it easily with a microscope. This neuron exhibits a bistability between a stable hyperpolarized down-state and a stable depolarized spiking state. It is one of the first discovered neurons, however its electrical behaviour is not well understood so far. The principal question of the thesis is to model the electrophysiology of the Purkinje cell to advance the understanding of its regulation mechanisms. More particularly, the objective of the thesis is to explore recent work about the role of the calcium current in neuronal excitability as a possible mechanism underlying the bistability observed in the Purkinje cell. The electrical activity of the Purkinje cell is reproduced in this thesis thanks to a reduced physiological model which can be seen as an intermediate between a detailed model with dendritic compartments and an abstract model of bistability. This novel model is the main contribution of the thesis. Its main ingredients are on the one hand a fast sodium current and a slow potassium restorative current whose particular kinetics account for the up-state excitability, and on the other hand a slow regenerative calcium current and an ultraslow calcium-dependent potassium current for bistability. The proposed model suggests several implications. First, a complex compartmental model seems unnecessary to reproduce the electrophysiology of the cell, although the profuse dendrites are an important characteristic of the Purkinje neuron. Secondly, the Purkinje neuron appears to be regulated by the same mechanisms as other bistable neurons such as the thalamocortical (TC) or subthalamic nucleus (STN) neurons. Its behaviour depends on the same feedback mechanisms (a fast regenerative sodium current, a slow restorative potassium current and a slow regenerative calcium current), event though the temporal signature is markedly different because of the specific channel kinetics primarily of the slow potassium current. Finally this novel model makes the Purkinje cell modelling amenable to robustness and modulation studies, as recently shown for similar neurons. [less ▲]

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See detailCellular source and amount of vascular endothelial growth factor and platelet-derived growth factor in tumors determine response to angiogenesis inhibitors.
Sennino, Barbara; Kuhnert, Frank; Tabruyn, Sébastien ULg et al

in Cancer Research (2009), 69(10), 4527-36

Vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and their receptors are important targets in cancer therapy based on angiogenesis inhibition. However, it is unclear ... [more ▼]

Vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and their receptors are important targets in cancer therapy based on angiogenesis inhibition. However, it is unclear whether inhibition of VEGF and PDGF together is more effective than inhibition of either one alone. Here, we used two contrasting tumor models to compare the effects of inhibiting VEGF or PDGF alone, by adenovirally generated soluble receptors, to the effects of inhibiting both together. In RIP-Tag2 tumors, VEGF and PDGF inhibition together reduced tumor vascularity and abundance of pericytes. However, VEGF inhibition reduced tumor vascularity without decreasing pericyte density, and PDGF inhibition reduced pericytes without reducing tumor vascularity. By contrast, in Lewis lung carcinomas (LLC), inhibition of VEGF or PDGF reduced blood vessels and pericytes to the same extent as did inhibition of both together. Similar results were obtained using tyrosine kinase inhibitors AG-013736 and imatinib. In LLC, VEGF expression was largely restricted to pericytes and PDGF was largely restricted to endothelial cells, but, in RIP-Tag2 tumors, expression of both growth factors was more widespread and significantly greater than in LLC. These findings suggest that inhibition of PDGF in LLC reduced pericytes, and then tumor vessels regressed because pericytes were the main source of VEGF. The vasculature of RIP-Tag2 tumors, in which most VEGF is from tumor cells, was more resistant to PDGF inhibition. The findings emphasize the interdependence of pericytes and endothelial cells in tumors and the importance of tumor phenotype in determining the cellular effects of VEGF and PDGF inhibitors on tumor vessels. [less ▲]

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See detailCellular therapy for cardiac tissue repair by haematopoietic and mesenchymal stem cells
DELGAUDINE, Marie ULg

Master of advanced studies dissertation (2004)

A conceivable strategy in cell and gene therapy is the use of adult stem cells isolated from bone marrow. We defined the optimal conditions for the culture of human and murine mesenchymal stem cells (hMSC ... [more ▼]

A conceivable strategy in cell and gene therapy is the use of adult stem cells isolated from bone marrow. We defined the optimal conditions for the culture of human and murine mesenchymal stem cells (hMSC and mMSC). We observed that the MSC of both species had a special morphology thanks to which it was possible to isolate them in flow cytometry on the basis of the size and granulosity parameter only. We analyzed the MSC phenotype by flow cytometry and observed that the hMSC were CD31-, CD34-, CD45, CD80- and HLA-DR- while they expressed CD73, CD90, CD105 and HLA-1 antigens. mMSC phenotype was CD34-, CD45-, CD11b-, CD106+ and Sca-1+. We also wanted to determine the frequency in progenitors among the mMSC amplified in vitro. To do so, we first assessed the enrichment in CFU-F (Colony-Forming Units – Fibroblast) progenitors. This method consisted in a secondary culture in liquid medium optimized for the development of colonies of mesenchymal origin. We were able to observe an increase of the CFU-F during the MSC passages. Then, we developed a method in order to assess the progenitors frequency by culturing MSC at limiting dilutions (CFUF-IC, Colony-Forming Units Fibroblast-Initiating cells). Once again, we were able to notice that the frequency in progenitors increased during the successive passages. The ratio between the number of CFU-F and the frequency in progenitors amounted to ± 10. We also performed differentiation assays. We were able to differentiate the mMSC in fat cells, chondrocytes and osteoblasts. Finally, we developed a model of left coronary artery ligature in mice as well as immunohistochemical markers showing the antigens CD31, -actinin and connexin 43. With the intent to inject various types of grafts in this animal model, we also studied the cell cycle of the stem cells by Hoechst staining. Fluorescence analysis of mMSC isolated from EGFP transgenic mice revealed that their fluorescence increased from ± 30% in marrow to more than 90% for the mMSC isolated and amplified via an in vitro culture. [less ▲]

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See detailCellular Uptake Of Antennapedia Penetratin Peptides Is A Two-Step Process In Which Phase Transfer Precedes A Tryptophan-Dependent Translocation
Dom, G.; Shaw-Jackson, C.; Matis, C. et al

in Nucleic Acids Research (2003), 31(2), 556-61

Several homeodomains and homeodomain-containing proteins enter live cells through a receptor- and energy-independent mechanism. Translocation through biological membranes is conferred by the third alpha ... [more ▼]

Several homeodomains and homeodomain-containing proteins enter live cells through a receptor- and energy-independent mechanism. Translocation through biological membranes is conferred by the third alpha-helix of the homeodomain, also known as Penetratin. Biophysical studies demonstrate that entry of Penetratin into cells requires its binding to surface lipids but that binding and translocation are differentially affected by modifications of some physico-chemical properties of the peptide, like helical amphipathicity or net charge. This suggests that the plasma membrane lipid composition affects the internalization of Penetratin and that internalization requires both lipid binding and other specific properties. Using a phase transfer assay, it is shown that negatively charged lipids promote the transfer of Penetratin from a hydrophilic into a hydrophobic environment, probably through charge neutralization. Accordingly, transfer into a hydrophobic milieu can also be obtained in the absence of negatively charged lipids, by the addition of DNA oligonucleotides. Strikingly, phase transfer by charge neutralization was also observed with a variant peptide of same charge and hydrophobicity in which the tryptophan at position 6 was replaced by a phenylalanine. However, Penetratin, but not its mutant version, is internalized by live cells. This underscores that charge neutralization and phase transfer represent only a first step in the internalization process and that further crossing of a biological membrane necessitates the critical tryptophan residue at position 6. [less ▲]

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See detailCellular uptake of liposomes monitored by confocal microscopy and flow cytometry
Ducat, Emilie ULg; Evrard, Brigitte ULg; Peulen, Olivier ULg et al

in Journal of Drug Delivery Science and Technology [=JDDST] (2011), 21(6), 469-477

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See detailCellular uptake of long-circulating pH-sensitive liposomes: evaluation of the liposome and its encapsulated material penetration in cancer cells
Ducat, Emilie ULg; Deprez, Julie ULg; Peulen, Olivier ULg et al

in Drug Discovery Today (2010, December), 15(23-24), 1079-1114

Print 3G, a peptidic antagonist of oncoprotein involved in breast cancer, could reduce the angiogenic development of breast tumors, leading to tumor dormancy. The necessity of intravenous administration ... [more ▼]

Print 3G, a peptidic antagonist of oncoprotein involved in breast cancer, could reduce the angiogenic development of breast tumors, leading to tumor dormancy. The necessity of intravenous administration of Print 3G led to the development of long-circulating liposomes as drug carriers. Pegylated liposomes, too large to be collected by fenestrated organs, accumulate passively in solid tumors thanks to the EPR effect. The strategy was to combine the protective properties of PEG with the transfection properties of pH-sensitive lipids which could promote the uptake of liposomes by cells and avoid lysosomal sequestration and degradation of entrapped materials such as peptides. In this study, we compare two formulations in terms of cellular uptake using confocal microscopy. The first one is composed of SPC:CHOL:mPEG-750-DSPE (47:47:6), used as "standard" liposomes, and the second one of DOPE:CHEMS:CHOL:mPEG750-DSPE (43:21:30:6), used as pH-sensitive liposomes. First, we evaluated the penetration of an encapsulated model molecule, calcein, in Hs578t human breast cancer epithelial cells. When calcein was encapsulated in standard liposomes, its penetration was effective only in few cells. On the contrary, a majority of cells were fluorescent when calcein-loaded pH-sensitive liposomes were applied for 3 hours on cells. Secondly, we studied the penetration of liposomes themselves in Hs578t cells using 25-[(nitrobenzoxadiazolyl)methylamino]nor-cholesterol (NBD-CHOL) as a fluorescent marker of the phospholipid membrane. The obtained results were comparable to those obtained with calcein: a higher penetration of liposome was observed for pH-sensitive liposomes. Finally, the cellular uptake of liposomes using both NBD-CHOL and rhodamine encapsulated in the inner cavity of vesicles was evaluated with Hs578t cells and compared with WI26 human diploid lung fibroblast cells. Thanks to this experiment, we could follow simultaneously the cell distribution of the encapsulated material and of the liposome itself. Confocal pictures obtained with pH-sensitive liposomes on both WI26 and Hs578t cells allow us to visualize the co-localized red and green colors of rhodamine and NBD-CHOL, with a higher concentrated area near the nucleus. In comparison with "standard" liposomes, we observed a higher penetration of the encapsulated material and of the liposome itself in breast cancer cells. Moreover, we visualized a colocalization near the nucleus of liposomes components. Concerning results obtained with fibroblastic cells, there was no difference in terms of cellular uptake between the two formulations. In perspective, we would like to compare these results, obtained with model molecules, with experiments performed with biotinylated Print 3G to assess its cellular distribution. Moreover, it would be interesting to correlate results obtained with confocal microscopy with a possible increase of the peptide efficacy against cancer cells when it is encapsulated in long-circulating pH-sensitive liposomes. [less ▲]

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See detailA cellulase from a psychrophilic microorganism: 3D structures of its native form and its complex with cellobiose
Violot, S.; Gouet, P.; Haser, Richard et al

Poster (2002)

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See detailCellulase hydrolysis Reactor : Effects of Agitation on cellulase activity.
Van Rollenghem, I.; Paquot, Michel ULg; Parajo, C. et al

Poster (1986, June)

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See detailCellulase involvement in the bacterial cellulose biosynthesis
Delsaute, Maud ULg; Berlemont, Renaud ULg; Bauvois, Cédric et al

Poster (2012)

Detailed reference viewed: 47 (11 ULg)
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See detailCellulase involvement in the cellulose biosynthesis of Pseudomonas stutzeri
Delsaute, Maud ULg; Berlemont, Renaud ULg; Paulus, Virginie et al

Poster (2011)

Detailed reference viewed: 32 (6 ULg)
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See detailCellulases catalysed cellulose polymerisation
Delsaute, Maud ULg; Berlemont, Renaud ULg; Renson, Thomas ULg et al

Poster (2010)

Detailed reference viewed: 38 (26 ULg)