Publications

2005

Sensibilité structurale et sources de contraste en microscopie par génération de troisième harmonique (THG) appliquée à la biologie
- Débarre Delphine
- Supatto Willy
- Pena Ana-Maria
- Fabre Aude
- Tordjmann T.
- Combettes Laurent
- Schanne-Klein Marie-Claire
- Beaurepaire Emmanuel
, 2005.
Nonlinear optical spectroscopy of chiral molecules
- Hache François
, 2005.
Electrical activity alterations induced by chronic absorption of lindane (gamma-hexachlorocyclohexane) trace concentrations in adult rat heart
- Sauviat Martin-Pierre
- Bouvet Suzanne
- Godeau Gaston
- Pages Nicole
Canadian Journal of Physiology and Pharmacology, NRC Research Press, 2005, 83 (3), pp.243. The heart of adult rat offspring, born to mothers treated with trace concentrations of lindane (0.5 to 2 ppb) through a beverage and to mothers chronically treated with lindane (CL-T) with the same trace concentration, also through a beverage, during lactation and growth has a round shape and accumulates lindane. The left ventricle (LV) presents a hypertrophied area, atrophied papillary muscles, and unorganized collagen bundles and layers. These observations led us to study the electrical activity of their left ventricle papillary muscles (LVPM) by recording action potential using intracellular microelectrodes. CL-T shortened LVPM action potential duration (APD): 1 ppb shortened the plateau; 2 ppb shortened the plateau and the slow repolarizing phase. In CL-T (2 ppb) and untreated groups, low temperature (22 degrees C) decreased the resting potential and prolonged APD. TEA (tetraethylammonium; 1-2 mmol/L) partially lengthened CL-T (2 ppb lindane) APD. Quinidine (0.2 mmol/L) and E-4031 (10 nmol/L) prolonged CL-T APD, suggesting that the rapid delayed outward K+ current (I-Kr) was increased. Our results indicate the silent effects of chronic exposure to trace concentrations of lindane on the morphological and electrical activity of heart muscle. They demonstrate that chronic lindane treatment of female rats alters the tissue integrity and electrical activity in the LV of their offspring. (10.1139/Y04-132)
DOI : 10.1139/Y04-132
Chiroptical effects in the second harmonic signal of collagens I and IV
- Pena Ana-Maria
- Boulesteix Thierry
- Dartigalongue Thibault
- Schanne-Klein Marie-Claire
Journal of the American Chemical Society, American Chemical Society, 2005, 127 (29), pp.10314. We performed polarization-resolved surface second harmonic generation (SHG) experiments on thin films of collagen I and IV molecules, as well as conventional CD measurements. We found that collagen IV presents little CD and no SHG optical activity, whereas collagen I exhibits large chiroptical effects involving both one-electron and excitonic coupling mechanisms. We estimated that these chiral components enhance the SHG signal from fibrillar collagen in biological tissues by typically a factor of 2. By comparing the distinct behaviors of collagens I and IV in SHG microscopy and in surface SHG experiments, we concluded that SHG microscopy is a sensitive probe of the micrometer-scale structural organization of collagen in biological tissues. Cop. 2005 American Chemical Society. (10.1021/ja0520969)
DOI : 10.1021/ja0520969
Fourier transform measurement of two-photon excitation spectra: applications to microscopy and optimal control
- Ogilvie Jennifer P.
- Kubarych Kevin J.
- Alexandrou Antigoni
- Joffre Manuel
Optics Letters, Optical Society of America - OSA Publishing, 2005, 30, pp.911. We report a novel Fourier transform method for measuring two-photon excitation spectra. We demonstrate this method using simple dye molecules and discuss its applications in two-photon fluorescence microscopy and optimal control. This method facilitates an intuitive interpretation of recent control experiments in terms of tuning the nonlinear spectrum of the exciting laser source.
Evaluation, in vitro, du potentiel thérapeutique d'extraits de plantes traditionnellement utilisés pour traiter la ciguatera dans le Pacifique.
- Boydron-Le Garrec Raphaële
- Benoit Evelyne
- Sauviat Martin-Pierre
- Lewis Richard L.
- Molgó Jordi
- Laurent Dominique
, 2005, pp.207-212.
In vivo modulation of morphogenetic movements in Drosophila embryos with femtosecond laser pulses
- Supatto Willy
- Débarre Delphine
- Moulia Bruno B.
- Brouzés Eric
- Martin Jean-Louis
- Farge Emmanuel
- Beaurepaire Emmanuel
Proceedings of the National Academy of Sciences of the United States of America, National Academy of Sciences, 2005, 102 (4), pp.1047. The complex biomechanical events associated with embryo development are investigated in vivo, by using femtosecond laser pulse-induced ablation combined with multimodal nonlinear microscopy. We demonstrate controlled intravital ablations preserving local cytoskeleton dynamics and resulting in the modulation of specific morphogenetic movements in nonmutant Drosophila embryos. A quantitative description of complex movements is obtained both in GFP-expressing systems by using whole-embryo two-photon microscopy and in unlabeled nontransgenic embryos by using third harmonic generation microscopy. This methodology provides insight into the issue of mechano-sensitive gene expression by revealing the correlation of in vivo tissue deformation patterns with Twist protein expression in stomodeal cells at gastrulation. (10.1073/pnas.0405316102)
DOI : 10.1073/pnas.0405316102
Emission properties and applications of nanostructured luminescent oxide nanoparticles
- Giaume D.
- Buissette V.
- Lahlil K.
- Gacoin Thierry
- Boilot Jean-Pierre
- Casanova Didier
- Beaurepaire Emmanuel
- Sauviat Martin-Pierre
- Alexandrou Antigoni
, 2005.
Dynamique du monoxyde d'azote (NO) au sein du site actif de cytochrome c oxydases
- Pilet Eric
- Nitschke Wolfgang
- Rappaport Fabrice
- Liebl Ursula
- Vos Marten H.
, 2005, pp.poster.
Time-Resolved Circular Dichroism in Carbonmonoxy-Myoglobin: The Central Role of the Proximal Histidine
- Dartigalongue Thibault
- Hache François
, 2005.

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