References of "Blacher, Silvia"
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See detailQuantification of in Vivo Tumor Invasion and Vascularization by Computerized Image Analysis
Blacher, Silvia ULg; Jost, M.; Melen-Lamalle, Laurence ULg et al

in Microvascular Research (2008), 75(2), 169-78

The matrix-inserted surface transplantation model is an in vivo assay used to analyse the kinetics of tumor-vessel interactions during different stages of skin carcinoma progression. This system allows ... [more ▼]

The matrix-inserted surface transplantation model is an in vivo assay used to analyse the kinetics of tumor-vessel interactions during different stages of skin carcinoma progression. This system allows the study of host-tumor interface, i.e. penetration of tumor cells into normal host tissue as well as infiltration of normal host cells into the tumor. In the present study, image analysis algorithms for processing and quantifying the extent of such migratory and tissue remodeling events are presented. The proposed method is non-parametric and its originality lies in its particularity to take into account the specific geometry of tumor-host interface. This methodology is validated by evaluating the contribution of matrix metalloproteases (MMPs) in skin carcinoma invasion and vascularization through pharmacological and genetic approaches. [less ▲]

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See detailEffect of far-infrared radiation assisted drying on microstructure of banana slices: An illustrative use of X-ray microtomography in microstructural evaluation of a food product
Léonard, Angélique ULg; Blacher, Silvia ULg; Nimmol, Chatchai et al

in Journal of Food Engineering (2008), 85(1), 154-162

X-ray microtomography coupled with image analysis represents a non-destructive technique, which allows scanning an entire sample to obtain such information as total pore volume and pore size distribution ... [more ▼]

X-ray microtomography coupled with image analysis represents a non-destructive technique, which allows scanning an entire sample to obtain such information as total pore volume and pore size distribution without the need of serial cuts as in the case of scanning electron microscopy (SEM). The technique has been applied successfully to obtain reliable microstructural information of many products undergoing different physical and chemical processes. However, the technique has still found limited use in food processing. To illustrate the use of X-ray microtomography the technique was applied to investigate the effect of far-infrared radiation (FIR) assisted drying on microstructure of a food product viz. banana. Two representative drying techniques, i.e., low-pressure superheated steam drying (LPSSD) and vacuum drying (VACUUM) were tested. Banana slices were dried by LPSSD-FIR at two different temperatures (80 and 90 degrees C) at a fixed pressure of 7 kPa. The total pore volume and pore size distribution of dried banana slices were then determined using X-ray microtomography. The results were also compared with those of products dried by LPSSD without FIR. Far-infrared radiation was found to modify the structure of the dried bananas by increasing their final porosity. The same effect of FIR was also observed in the case of vacuum drying with FIR (VACUUM-FIR). An increase of the drying temperature was also found to globally lead to an increase in the final porosity of the products. (C) 2007 Elsevier Ltd. All rights reserved. [less ▲]

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See detailFormation mechanism of Y-junctions in arrays of multi-walled carbon nanotubes
Zilli, Dario; Blacher, Silvia ULg; Cukierman, Ana Lea et al

in Colloids and Surfaces A : Physicochemical and Engineering Aspects (2008), 327(1-3), 140-143

Transmission electron microscopy of arrays of multi-walled carbon nanotubes reveals the presence of numerous Y-junctions. The diameter distributions of the samples are found to be bimodal, with one mode ... [more ▼]

Transmission electron microscopy of arrays of multi-walled carbon nanotubes reveals the presence of numerous Y-junctions. The diameter distributions of the samples are found to be bimodal, with one mode corresponding to the branches and the other mode to the trunk of the Y-junctions. The analysis of the micrographs shows that the junctions form via the merger of metal particles during the tip-growth of the tubes. (C) 2008 Elsevier B.V. All rights reserved. [less ▲]

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See detailThe lymphatic ring assay: a new in vitro model of lymphangiogenesis
Bruyère, F; Melen-Lamalle, L; Blacher, Silvia ULg et al

in Acta Clinica Belgica (2008), 63

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See detailVascular architecture of breast cancer xenographs over-expressing MT4-MMP
Chabottaux, V; Thiry, Marc ULg; Blacher, Silvia ULg et al

in Acta Clinica Belgica (2008), 63

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See detailModeling Lymphangiogenesis in a three-dimensional culture system
Bruyere, Françoise; Melen-Lamalle, Laurence; Blacher, Silvia ULg et al

in Nature Methods (2008), 5(5), 431-437

Unraveling the molecular mechanisms of lymphangiogenesis is hampered by the lack of appropriate in vitro models of three-dimensional (3D) lymph vessel growth which can be used to exploit the potential of ... [more ▼]

Unraveling the molecular mechanisms of lymphangiogenesis is hampered by the lack of appropriate in vitro models of three-dimensional (3D) lymph vessel growth which can be used to exploit the potential of available transgenic mice. We developed a potent reproducible and quantifiable 3D-culture system of lymphatic endothelial cells, the lymphatic ring assay, bridging the gap between 2D-in vitro and in vivo models of lymphangiogenesis. Mice thoracic duct fragments are embedded in a collagen gel leading to the formation of lymphatic capillaries containing a lumen as assessed by electron microscopy and immunostaining. This assay phenocopies the different steps of lymphangiogenesis, including the spreading from a preexisting vessel, cell proliferation, migration and differentiation into capillaries. Our study provides evidence for the implication of an individual matrix metalloproteinase, MMP-2, during lymphangiogenesis. The lymphatic ring assay is a robust, quantifiable and reproducible system which offers new opportunities for rapid identification of unknown regulators of lymphangiogenesis. [less ▲]

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See detailIn situ observation of wall effects in activated carbon filters by X-ray microtomography
Léonard, Angélique ULg; Wullens, Hilda; Blacher, Silvia ULg et al

in Separation & Purification Technology (2008), 64(1), 127-130

X-ray microtomography is a powerful non-invasive visualisation technique which can be advantageously used to get a better understanding or dynamic adsorption processes. In the present work, this technique ... [more ▼]

X-ray microtomography is a powerful non-invasive visualisation technique which can be advantageously used to get a better understanding or dynamic adsorption processes. In the present work, this technique is shown to be able to detect wall effects during the dynamic adsorption of methyl iodide on activated carbon filters. The analysis of transversal cross-sections along the filter height clearly shows the existence of radial concentration profiles. These radial adsorption profiles are directly linked to velocity profiles due to a higher permeability at the wall. Obtaining Such in situ information constitutes a real progress in order to validate simulation models allowing predicting reliable breakthrough times. (C) 2008 Elsevier B.V. All rights reserved. [less ▲]

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See detailCritical opalescence points to thermodynamic instability:relevance to small-angle X-ray scattering of resorcinol–formaldehyde gel formation at low pH
Gommes, Cédric ULg; Job, Nathalie ULg; Pirard, Jean-Paul ULg et al

in Journal of Applied Crystallography (2008), 41(4), 663-668

During the formation at low pH of resorcinol–formaldehyde gels with a structure in the micrometre range, small-angle X-ray scattering exhibits a nonmonotonic intensity variation as a function of reaction ... [more ▼]

During the formation at low pH of resorcinol–formaldehyde gels with a structure in the micrometre range, small-angle X-ray scattering exhibits a nonmonotonic intensity variation as a function of reaction time. The data are analyzed in terms of scattering by statistical fluctuations of polymer concentration, the amplitude of which is maximal close to the critical point for phase separation between polymer and solvent. The data do not carry any morphological information, but they unambiguously show that the driving force of the gel formation is a thermodynamic instability of the polymerizing solution. [less ▲]

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See detailPersistence of an intact endometrial matrix and vessels structure in women exposed to VA-2914, a selective progesterone receptor modulator.
Ravet, Stéphanie ULg; Munaut, Carine ULg; Blacher, Silvia ULg et al

in Journal of Clinical Endocrinology and Metabolism (2008), 93(11), 4525-31

Background: VA-2914 is a selective progesterone receptor modulator with potential contraceptive activity that induces amenorrhea, whereas progestins cause endometrial spotting and bleeding. This abnormal ... [more ▼]

Background: VA-2914 is a selective progesterone receptor modulator with potential contraceptive activity that induces amenorrhea, whereas progestins cause endometrial spotting and bleeding. This abnormal bleeding due to progestins is a consequence of focal stromal proteolysis by an increase in naked vessel size and density. Objective: Our objective was to quantify the effects of VA-2914 on endometrial vascularization, fibrillar matrix, and vascular endothelial growth factor (VEGF)-A expression in endometrial biopsies from 41 women before and after 12 wk daily treatment with a placebo, or 2.5, 5, or 10 mg VA-2914. Methods: Collagen fibrillar network was stained by silver impregnation. Vessel area, density, and structure were quantified with a computer-assisted image analysis system after double immunostaining using an anti-von Willebrand factor (endothelial cells) and an anti- smooth muscle actin (vascular smooth muscle cells) marker antibody. VEGF-A mRNAs were quantified by RT-PCR and localized by immunohistochemistry. Results: The endometrial vessels, collagen network, and mRNA levels of VEGF-A were identical during the luteal phase at baseline and in VA-2914 treated women. VEGF-A distribution was unchanged. Conclusions: VA-2914 does not alter the endometrial matrix and cells, and does not modify the endometrial vessel morphology as compared with baseline biopsies. [less ▲]

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See detailHypoxia is responsible for soluble vascular endothelial growth factor receptor-1 (VEGFR-1) but not for soluble endoglin induction in villous trophoblast
Munaut, Carine ULg; Lorquet, Sophie ULg; Pequeux, Christel ULg et al

in Human Reproduction (2008), 23(6), 1407-15

BACKGROUND: Pre-eclampsia is a pregnancy disorder characterized by a maternal endothelial cell dysfunction associated with low levels of circulating placental growth factor (PlGF) and increased levels of ... [more ▼]

BACKGROUND: Pre-eclampsia is a pregnancy disorder characterized by a maternal endothelial cell dysfunction associated with low levels of circulating placental growth factor (PlGF) and increased levels of total vascular endothelial growth factor (VEGF), soluble VEGF receptor-1 (sVEGFR-1), and soluble endoglin, a transforming growth factor b1 and 3 coreceptor. Here, we tested the hypothesis that these altered levels of angiogenic cytokines and of the anti-angiogenic soluble forms of cytokine receptors could be the consequence of hypoxia. METHODS: Normal human umbilical vein endothelial cells, immortalized first trimester extravillous trophoblast cells (HTR8/SVneo) and first trimester placental villi explants (8–14 weeks) were used for culture under normoxia (20% O2) or hypoxia (1% O2). Culture media were collected for the measurement of cytokines by enzyme-linked immunosorbent assay. Total RNA was extracted for RT-PCR analysis. RESULTS: Under hypoxia, villous trophoblast expressed higher levels of VEGF, VEGFR-1, sVEGFR-1 and VEGFR-2 mRNAs (P < 0.001), and secreted more VEGF and sVEGFR-1 proteins (P < 0.05). In contrast, PlGF mRNA and protein were decreased in 1% O2 (P < 0.001), whereas endoglin (Eng) was not modulated. Additionally, sVEGFR-1 directly abolished VEGF/PlGF-induced angiogenesis in the rat aortic ring assay. CONCLUSIONS: Our results support the hypotheses that, in pre-eclampsia, (i) overproduction of VEGF family factors by pre-eclamptic placenta is a consequence of induced hypoxia; (ii) overproduction of sVEGFR-1 by hypoxic villous trophoblast accounts for maternal free VEGF depletion; (iii) low circulating level of free PlGF is not only related to sVEGFR-1 overproduction, but also to hypoxia induced mRNA down-regulation; (iv) Eng is not modulated by hypoxia.. [less ▲]

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See detailEvolution of mechanical properties and final textural properties of resorcinol-formaldehyde xerogels during ambient air drying
Léonard, Angélique ULg; Blacher, Silvia ULg; Crine, Michel ULg et al

in Journal of Non-Crystalline Solids (2008), 354(10-11), 831-838

Porous carbon xerogels can be obtained by convective drying of resorcinol (R)-formaldehyde (F) hydrogels, followed by pyrolysis. Drying conditions have to be carefully controlled when crack-free monoliths ... [more ▼]

Porous carbon xerogels can be obtained by convective drying of resorcinol (R)-formaldehyde (F) hydrogels, followed by pyrolysis. Drying conditions have to be carefully controlled when crack-free monoliths with well-defined shape and size are required. The knowledge of the mechanical properties of the RF xerogels and their evolution with water content is essential to model their thermo-hygro-mechanical behavior during convective drying and avoid mechanical stresses leading to deformation and cracking of the sample. The shrinkage behavior and the mechanical properties of RF xerogels obtained with R/C ratio ranging from 300 to 1500 were investigated. R/C greatly influences the shrinkage and mechanical properties of the wet gel, on the one hand, and the mechanical and textural properties of the dried gel, on the other hand. The smaller the R/C, the higher the shrinkage, the stiffening, and the viscoelastic character of the xerogels. Water content has an influence on both the stiffness of the gels and the viscoelastic response. Generally, samples lose their mechanical viscous character and become more rigid when they are dried. Finally., mercury porosimetry measurements showed that the gels exhibit a marked lowering of their stiffness upon compression, interpreted as a result of the heterogeneity of the microstructure. (C) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailImplication of soluble receptors of VEGF, sVEGFR-1 and sVEGFR-2, in angiogenesis
Lorquet, Sophie ULg; Berndt, Sarah ULg; Blacher, Silvia ULg et al

in American Journal of Reproductive Immunology (2008), 60/1

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See detailImplication of VEGF receptor soluble forms, sVEGFR-1 and sVEGFR-2, in angiogenesis
Lorquet, Sophie ULg; Berndt, Sarah ULg; Blacher, Silvia ULg et al

in Acta Clinica Belgica (2008), 63/1

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See detailThe microstructure of hybrid silica gels and its modification by evaporative and supercritical dryings
Gommes, Cédric ULg; Blacher, Silvia ULg; Pirard, Jean-Paul ULg et al

in Journal of Sol-Gel Science and Technology (2007), 44(3), 211-218

The effect of evaporative drying on the pore size of two series of hybrid silica gels is investigated by combining beam bending on the gels and mercury porosimetry on the aerogels and xerogels with ... [more ▼]

The effect of evaporative drying on the pore size of two series of hybrid silica gels is investigated by combining beam bending on the gels and mercury porosimetry on the aerogels and xerogels with transmission electron microscopy on the xerogels. It is shown that the shrinkage of the pores during drying is different in the two series: in one series the pores shrink proportionally to their volume, in the other the pores collapse until they all reach the same size. The experimental data enable us to discuss the relation between these two different behaviours and the different morphology of the two series of gels. [less ▲]

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See detailEndometrial vessel maturation in women exposed to levonorgestrel-releasing intrauterine system for a short or prolonged period of time
Ravet, Stéphanie ULg; Labied, Soraya ULg; Blacher, Silvia ULg et al

in Human Reproduction (2007), 22(12), 3084-3091

BACKGROUND: Levonorgestrel-releasing intrauterine system (LNG-IUS), although inserted to reduce heavy menstruation, causes irregular early transient bleeding. The objective of the study was to document ... [more ▼]

BACKGROUND: Levonorgestrel-releasing intrauterine system (LNG-IUS), although inserted to reduce heavy menstruation, causes irregular early transient bleeding. The objective of the study was to document quantitative changes in endometrial vessels of short- (< or =3 months) and long-term (> or =12 months) LNG users. The area, density and maturation of endometrial vessels were quantified in 19 endometrial biopsies of women with LNG-IUS and in 10 normally ovulating patients during mid-luteal phase. METHODS: Vessel maturation was evaluated by double immunostaining using anti-von Willebrand factor (endothelial cell marker) and anti-alpha Smooth Muscle Actin (vascular smooth muscle cells) antibodies. Vessel area, number and density were quantified with a novel computer-assisted image analysis system. RESULTS: Endometrium exposed to LNG-IUS for 1-3 months displayed a 11.5-fold increase in small naked vessel number. The partially mature vessel (alphaSMA partially positive) number increased six times. After long-term LNG-IUS treatment, the immature and partially mature vessel number remained four times higher than in the control group. Vessel area and density also increased dramatically in a time-dependent pattern with LNG-IUS use. CONCLUSIONS: Levonorgestrel affects blood vessel number, area, density and maturation in a time-dependent pattern that may explain the early transient increase in breakthrough bleeding with the LNG-IUS. [less ▲]

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See detailInhibition of tumor growth and metastasis establishment by adenovirus-mediated gene transfer delivery of the antiangiogenic factor 16K hPRL
Nguyen, Ngoc-Quynh-Nhu ULg; Cornet, Anne ULg; Blacher, Silvia ULg et al

in Molecular Therapy : The Journal of the American Society of Gene Therapy (2007), 15(12), 2094-2100

Tumor metastases, the most fearsome aspect of cancer, are generally resistant to conventional therapies. Angiogenesis is a crucial aspect of tumor growth and metastatic dissemination. Antiangiogenic ... [more ▼]

Tumor metastases, the most fearsome aspect of cancer, are generally resistant to conventional therapies. Angiogenesis is a crucial aspect of tumor growth and metastatic dissemination. Antiangiogenic therapy, therefore, holds potential as an attractive strategy for inhibiting metastasis development. Human 16K PRL (16K hPRL), a potent inhibitor of angiogenesis, has been demonstrated to prevent tumor growth in two xenograft mouse models, but whether it also affects tumor metastasis is unknown. In this study we will investigate the ability of 16K hPRL to prevent the establishment of metastasis. We demonstrate that 16K hPRL administered via adenovirus-mediated gene transfer, inhibits tumor growth by 86% in a subcutaneous (SC) B16-F10 mouse melanoma model. Computer-assisted image analysis shows that 16K hPRL treatment results in a reduction of tumor-vessel length and width, leading to a 57% reduction of average vessel size. In a pre-established tumor model, moreover, 16K hPRL can significantly delay tumor development. Finally, for the first time, we provide evidence that 16K hPRL considerably reduces the establishment of B16-F10 metastasis in an experimental lung metastasis model. Both the number and size of metastases are reduced by 50% in 16K hPRL-treated mice. These results highlight a potential role for 16K hPRL in anticancer therapy for both primary tumors and metastases. [less ▲]

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See detailObservation of wall effects in activated carbon filters by x-ray µCT
Léonard, Angélique ULg; Wullens, Hilda; Blacher, Silvia ULg et al

in Mc Cann, H.; Johansen, G. A. (Eds.) Proceedings of the 5th World Congress on Industrial Process Tomography, Bergen, Norway, September 6-9, 2007 (2007, September)

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See detailWater desorption isotherms of resorcinol-formaldehyde and carbon xerogels
Léonard, Angélique ULg; Escalona, I.; Job, Nathalie ULg et al

Poster (2007, July 15)

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