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81documents trouvés

18268
01/04/2018

Lymphatic Vasculature Requires Estrogen Receptor- Signaling to Protect From Lymphedema

F.MORFOISSE, F.TATIN, B.CAHPUT, N.THERVILLE, C.VAYSSE, R.METIVIER, J.MALLOIZEL-DELAUNAY, F.PUJOL, A.C.GODET, F.DE TONI, F.BOUDOU, K.GRENIER, D.DUBUC, E.LACAZETTE, A.C.PRATS, J.GUILLERMET-GUIBERT, F.LENFANT, B.GARMY-SUSINI

I2MC, CHU Toulouse, CRCT-INSERM, IUCT-Oncopole, IGDR, UT1, MH2F

Revue Scientifique : Arteriosclerosis, Thrombosis, and Vascular Biology, Vol.38, N°6, pp.1346-1357, Avril 2018 , N° 18268

Lien : https://hal-univ-rennes1.archives-ouvertes.fr/hal-01863214

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Abstract

Objective Estrogens exert beneficial effect on the blood vascular system. However, their role on the lymphatic system has been poorly investigated. We studied the protective effect of the 17 estradiolthe most potent endogenous estrogenin lymphedemaa lymphatic dysfunction, which results in a massive fluid and fat accumulation in the limb. Approach and Results Screening of DNA motifs able to mobilize ERs (estrogen receptors) and quantitative real-time polymerase chain reaction analysis revealed that estradiol promotes transcriptional activation of lymphangiogenesis-related gene expression including VEGF (vascular endothelial growth factor)-D, VEGFR (VEGF receptor)-3, lyve-1, and HASs (hyaluronan synthases). Using an original model of secondary lymphedema, we observed a protective effect of estradiol on lymphedema by reducing dermal backflowa representative feature of the pathology. Blocking ER by tamoxifenthe selective estrogen modulatorled to a remodeling of the lymphatic network associated with a strong lymphatic leakage. Moreover, the protection of lymphedema by estradiol treatment was abrogated by the endothelial deletion of the receptor ER in Tie2-Cre; ERlox/lox mice, which exhibit dilated lymphatic vessels. This remodeling correlated with a decrease in lymphangiogenic gene expression. In vitro, blocking ER by tamoxifen in lymphatic endothelial cells decreased cell-cell junctions, inhibited migration and sprouting, and resulted in an inhibition of Erk but not of Akt phosphorylation. Conclusions Estradiol protection from developing lymphedema is mediated by an activation of its receptor ER and is antagonized by tamoxifen. These findings reveal a new facet of the estrogen influence in the management of the lymphatic system and provide more evidence that secondary lymphedema is worsened by hormone therapy.

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18007
01/02/2018

Ciguatoxins activate the Calcineurin signalling pathway in Yeasts: Potential for development of an alternative detection tool?

H.MARTIN-YKEN, C.GIRONDE, S.DERICK, H.TAIANA DARIUS, C.FURGER, D.LAURENT, M.CHINAIN

LISBP, MH2F, ILM, Papeete, Toulouse III

Revue Scientifique : Environmental Research, Vol.162, pp.144-151, Février 2018 , N° 18007

Lien : https://hal.archives-ouvertes.fr/hal-01680541

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Ciguatoxins (CTXs) are lipid-soluble polyether compounds produced by dinoflagellates from the genus Gambierdiscus spp. typically found in tropical and subtropical zones. This endemic area is however rapidly expanding due to environmental perturbations, and both toxic Gambierdiscus spp. and ciguatoxic fishes have been recently identified in the North Atlantic Ocean (Madeira and Canary islands) and Mediterranean Sea. Ciguatoxins bind to Voltage Gated Sodium Channels on the membranes of sensory neurons, causing Ciguatera Fish Poisoning (CFP) in humans, a disease characterized by a complex array of gastrointestinal, neurological, neuropsychological, and cardiovascular symptoms. Although CFP is the most frequently reported non bacterial food-borne poisoning worldwide, there is still no simple and quick way of detecting CTXs in contaminated samples. In the prospect to engineer rapid and easy-to-use CTXs live cells-based tests, we have studied the effects of CTXs on the yeast Saccharomyces cerevisiae, a unicellular model which displays a remarkable conservation of cellular signalling pathways with higher eukaryotes. Taking advantage of this high level of conservation, yeast strains have been genetically modified to encode specific transcriptional reporters responding to CTXs exposure. These yeast strains were further exposed to different concentrations of either purified CTX or micro-algal extracts containing CTXs. Our data establish that CTXs are not cytotoxic to yeast cells even at concentrations as high as 1μM, and cause an increase in the level of free intracellular calcium in yeast cells. Concomitantly, a dose-dependent activation of the calcineurin signalling pathway is observed, as assessed by measuring the activity of specific transcriptional reporters in the engineered yeast strains. These findings offer promising prospects regarding the potential development of a yeast cells-based test that could supplement or, in some instances, replace current methods for the routine detection of CTXs in seafood products

142177
15044
11/12/2017

Microwave biosensors for non-invasive molecular and cellular investigations

K.GRENIER, D.DUBUC

MH2F

Ouvrage (contribution) : Medical and Biological Microwave Sensors and Systems, Cambridge University Press, N°ISBN 9781107297302, Décembre 2017, 25p. , N° 15044

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Abstract

In this comprehensive work, experts in the field detail recent advances in medical and biological microwave sensors and systems, with chapters on topics such as implantable sensors, wearable microwave tags, and UWB technology. Each chapter explores the theory behind the technology, as well as its design and implementation. This is supported by practical examples and details of experimental results, along with discussion of system design, design trade-offs, and possible constraints and manufacturing issues. Applications described include intracranial pressure monitoring, vital signs monitoring, and non-invasive molecular and cellular investigations. Presenting new research and advances in the field, and focusing on the state of the art in medical and biological microwave sensors, this work is an invaluable resource for enthusiastic researchers and practicing engineers in the fields of electrical engineering, biomedical engineering, and medical physics.

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17358
15/10/2017

Microwave microfluidic sensor based on a microstrip splitter/combiner configuration and split ring resonators (SRR) for dielectric characterization of liquids

P.VELEZ, L.SU, K.GRENIER, J.MATA-CONTRERAS, D.DUBUC, F.MARTIN

MH2F, UAB

Revue Scientifique : IEEE Sensors Journal, Vol.17, N°20, pp.6589-6598, Octobre 2017 , N° 17358

Lien : https://hal.archives-ouvertes.fr/hal-01597713

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Abstract

A microwave microfluidic sensor for dielectric characterization of liquids in real time is presented in this paper. The sensor is implemented in microstrip technology and consists of a symmetric splitter/combiner configuration loaded with a pair of identical split ring resonators (SRRs) and microfluidic channels placed on top of them (gap region). The sensor works in differential mode and sensing is based on frequency splitting. Thus, if the structure is unloaded or if it is symmetrically loaded with regard to the axial plane, only one transmission zero (notch) in the frequency response appears. However, if the axial symmetry is disrupted (e.g., by the presence of different liquids in the channels), two transmission zeros arise, and the difference in magnitude (notch depth) and frequency between such transmission zeros is indicative of the difference in the dielectric properties (complex dielectric constant). A circuit schematic, including transmission line sections to describe the distributed components, lumped elements to account for the SRRs and their coupling to the lines and lumped elements to model the liquid properties, is presented and validated. After proper calibration, the functionality of the proposed sensor is demonstrated by measuring the complex permittivity in solutions of deionized (DI) water and ethanol as a function of the ethanol content. Index Terms— Microwave sensors, differential sensors, microfluidics, dielectric characterization of liquids, permittivity measurements, microstrip technology, split ring resonator (SRR).

141177
17361
22/09/2017

Modeling and analysis of pairs of open complementary split ring resonators (OCSRRs) for differential permittivity sensing

P.VELEZ, L.SU, J.MATA-CONTRERAS, F.MARTIN, K.GRENIER, D.DUBUC

MH2F, UAB

Manifestation avec acte : IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes ( IMWS-AMP ) 2017 du 20 septembre au 22 septembre 2017, Pavie (Italie), Septembre 2017, 3p. , N° 17361

Lien : https://hal.laas.fr/hal-01597746

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This paper is focused on the modeling and analysis of a pair of open complementary split ring resonators (OCSRR) for sensing purposes. Since the capacitance of the OCSRR is very sensitive to dielectric loading, it follows that the OCSRR pair is very useful for differential permittivity measurements. The proposed sensing approach is based on the measurement of the cross-mode S-parameters, particularly the cross-mode insertion loss, very sensitive to asymmetric loading. On the basis of the circuit model of the OCSRR, analytical expressions for the cross-mode insertion loss under small perturbations (asymmetries) are derived. Such expressions, of interest for sensor design, are validated through circuit and electromagnetic simulations.

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17359
09/06/2017

Microwave permittivity extraction of individual biological cells submitted to different stimuli

A.ZEDEK, D.DUBUC, K.GRENIER

MH2F

Manifestation avec acte : IEEE International Microwave Symposium ( IMS ) 2017 du 04 juin au 09 juin 2017, Honolulu (USA), Juin 2017, 4p. , N° 17359

Lien : https://hal.laas.fr/hal-01597796

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This paper describes, for the first time, the relative permittivity extraction of cells in their culture medium submitted to different stimuli by using a microwave biosensor, specifically developed to analyze single cells. The sensitive part of the device is constituted by a 5 μm coplanar gap, over which the cell is blocked by a mechanical trap. It allows to obtain the capacitive and conductive contrasts of a cell. Electromagnetic simulations where the cell (sphere) permittivity is tuned permit to define fitted calibration curves linking capacitive and conductive contrasts to the real and imaginary parts of the relative permittivity. Measurements are performed on various cells (in their culture medium) after different environmental stimuli in order to induce various biological stresses altering the cell state. Results show that this non-invasive technique, including the developed proper de-embedding post-process, provides the intrinsic dielectric image of single biological cells, which then reveals their biological state.

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17188
19/05/2017

Développement d'un biocapteur radiofréquence pour la détection de prolifération bactérienne

S.BOUBACAR, O.ZEMB, D.DUBUC, K.GRENIER, F.MOUTIER

MH2F, EXT

Manifestation avec acte : Journées Nationales Microondes ( JNM ) 2017 du 16 mai au 19 mai 2017, St Malo (France), Mai 2017, 4p. , N° 17188

Lien : https://hal.laas.fr/hal-01529811

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Cet article présente les premiers résultats d'un biocapteur radiofréquence développé pour la détection de la prolifération bactérienne dans le cadre d'une analyse d'antibiorésistance. Le capteur développé comporte une coupure capacitive dans une ligne micro-ruban, dans laquelle est placé un capillaire contenant les bactéries ou leur milieu seul. Les résultats obtenus valident la capacité de mesure RF à détecter la présence de bactéries dans leur milieu.

140322
17185
17/05/2017

In vitro and in vivo investigations toward near-field microwave-based detection of melanoma

D.DUBUC, K.GRENIER, F.MORFOISSE, B.SUSINI-GARMY

MH2F, I2MC

Manifestation avec acte : IEEE International Microwave Bio Conference ( IMBioC ) 2017 du 15 mai au 17 mai 2017, Goteborg (Suède), Mai 2017, 4p. , N° 17185

Lien : https://hal.laas.fr/hal-01529825

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To go toward non-invasive melanoma analysis without the requirement of biopsy, in vitro and in vivo investigations have been performed with near-field microwave sensing techniques. Preliminary dielectric study has been carried out on different types of skin crushes: normal skin and skin with a subcutaneous B16 melanoma tumor. Extracted dielectric properties permits to clearly discriminate the two samples. Based on these results, in vivo investigations-have been performed on living mice, leading to a possible microwave-based detection of melanoma, which should now be confirmed with statistical measurements. The dielectric results are in agreement with the observation through immune-analysis of increased vascular density in the presence of a tumor, i.e. water content rise.

140316
17115
16/05/2017

Extraction de la permittivité complexe de cellules biologiques individuelles dans la gamme des micro-ondes

A.ZEDEK, D.DUBUC, K.GRENIER

MH2F

Manifestation avec acte : Journées Nationales Microondes ( JNM ) 2017 du 16 mai au 19 mai 2017, St Malo (France), Mai 2017, 4p. , N° 17115

Lien : https://hal.laas.fr/hal-01529805

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Résumé

Ce papier décrit l'extraction de la permittivité de cellules individuelles soumissent à différents stimuli en utilisant un biocapteur micro-ondes, développé pour l'analyse de cellules uniques dans leur milieu de culture. La partie sensible du dispositif est constituée d'un gap coplanaire de 5μm, sur lequel la cellule est piégée par un bloqueur mécanique, permettant d'obtenir les contrastes capacitifs et conductifs d'une cellule. Des simulations électromagnétiques, dans lesquels la permittivité de la cellule (sphère) est ajustée, ont permis de définir des courbes de calibrage adaptées reliant contrastes capacitif et conductif aux parties réelles et imaginaires de la permittivité relative. Plusieurs mesures ont été effectuées sur différentes cellules (dans leur milieu de culture) après différents stimuli dans le but d'induire différents stresses altérant l'état de la cellule. Les résultats montrent que cette technique non-invasive, incluant un post-traitement de de-embedding, nous fournit l'image intrinsèque diélectrique d'une cellule biologique, qui par la suite révèle l'état biologique de celle-ci.

139753
17560
01/05/2017

A Distributed Extended Ebers–Moll Model Topology for SiGe Heterojunction Bipolar Phototransistors Based on Drift–Diffusion Hydrodynamic Behavior

A.BENNOUR, F.MOUTIER, J.L.POLLEUX, C.ALGANI, S.MAZER

LTTI laboratory, MH2F, UPEM, CNAM Paris

Revue Scientifique : IEEE Transactions on Electron Devices, Vol.64, N°5, pp.2267-2274, Mai 2017 , N° 17560

Lien : https://hal.archives-ouvertes.fr/hal-01708912

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This paper proposes a novel type of compact circuit model for silicon germanium (SiGe) heterojunction phototransistor (HPT) that is justified from the distributed nature of both its electrical and optical behaviors. The proposed model is based on a modified Ebers-Model structure and contains 28 different parameters. It is independent of the nature of the base bias (current or voltage), as opposed to existing models. The method to identify that the architecture of the model is original as it makes use of a drift-diffusion numerical simulation of a SiGe HPT adjusted to experimental data. A good fit of the model both in amplitude and phase is obtained through the nine optomicrowave S-parameters.

142596
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