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Your search keyword '"Viet Samuel Tran"' showing total 5 results
Start Over Author "Viet Samuel Tran" Topic 0302 clinical medicine
5 results on '"Viet Samuel Tran"'

1. Study of dural suture watertightness: an in vitro comparison of different sealants

Author

Gurkan Mutlu, Dorian Chauvet, Bernard George, Jean-Marc Allain, Viet Samuel Tran, service de neurochirurgie, Hôpital Lariboisière-Fernand-Widal [APHP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), CHU Pitié-Salpêtrière [AP-HP], and Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)

Subjects
medicine.medical_specialty, Leak, Cerebrospinal Fluid Rhinorrhea, Posterior fossa, Fibrin Tissue Adhesive, 03 medical and health sciences, 0302 clinical medicine, Suture (anatomy), Pressure, otorhinolaryngologic diseases, medicine, Humans, Major complication, [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], ComputingMilieux_MISCELLANEOUS, Cerebrospinal Fluid, Cerebrospinal Fluid Leak, Cerebrospinal fluid leak, medicine.diagnostic_test, business.industry, Suture Techniques, Thrombin, Fibrinogen, Proteins, Water, Interventional radiology, medicine.disease, Surgery, Drug Combinations, Resins, Synthetic, 030220 oncology & carcinogenesis, Skull base surgery, Tissue Adhesives, Dural closure, Dura Mater, Neurology (clinical), business, 030217 neurology & neurosurgery
Abstract

CSF leakages constitute a major complication of intradural procedures, especially for posterior fossa and skull base surgery. Dural suture watertightness is a decisive issue, and neurosurgeons routinely use different products to reinforce their dural closure. We have designed an experimental system capable of testing CSF leak pressure levels in order to compare two types of sutures in vitro and particularly four different sealants.Twenty-five fresh human cadaveric dural samples were removed and prepared for testing in a pressure chamber system connected to a hydraulic pressure motor. CSF leak levels were objectively registered. First, simple interrupted stitches were compared to running simple closure on 50-mm linear suture. Secondly, four sealants (two sealants/glues, Bioglue®, Duraseal®; two haemostatics, Tachosil®, Tissucol®) were tested. Statistical analysis was performed with paired Student's t-test.No significant difference between interrupted closure and running suture was observed (p = 0.079). All sealants increased the watertightness of the suture significatively. However, comparison of the means of the differences for each product revealed large variations. In the conditions of our experiment, one sealant (Duraseal®) and one haemostatic (Tachosil®) seemed to show better results. We observed two different types of leakage: at the dura-sealant interface and through the sealant itself.We have developed an experimental device capable of testing dural closure watertightness. Interrupted stitch suturing seemed no different from running simple closure. On the contrary, the sealants tested show different watertightness capacities.

Published
2011
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2. A 20-nm Step toward the Cell Membrane Preceding Exocytosis May Correspond to Docking of Tethered Granules

Author

Erdem Karatekin, Jean-Pierre Henry, Isabelle Fanget, Sophie Cribier, Viet Samuel Tran, Sébastien Huet, Institut de Biologie Physico-Chimique (UPR 1929), Université Paris Diderot - Paris 7 (UPD7), Institut de Biologie Physico-Chimique (Centre National de la Recherche Scientifique UPR 1929), Department of Chemical Engineering, Columbia University [New York], Cell Biology and Biophysics Unit, European Molecular Biology Laboratory [Grenoble] (EMBL), Université Pierre et Marie Curie - Paris 6 (UPMC), Institut de biologie physico-chimique (IBPC (FR_550)), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Perron, Nicolas

Subjects
Biophysics, chemistry.chemical_element, Priming (immunology), Enteroendocrine cell, Carcinoid Tumor, Calcium, Biology, Exocytosis, Cell membrane, Motion, 03 medical and health sciences, 0302 clinical medicine, Cell Line, Tumor, medicine, Humans, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Secretory Vesicles, Vesicle, Cell Membrane, [CHIM.ORGA] Chemical Sciences/Organic chemistry, Secretory Vesicle, Cell biology, Membrane, medicine.anatomical_structure, chemistry, Cell Biophysics, 030217 neurology & neurosurgery
Abstract

International audience; In endocrine cells, plasma membrane (PM)-bound secretory granules must undergo a number of maturation stages (i.e., priming) to become fusion-competent. Despite identification of several molecules involved in binding granules to the PM and priming them, the exact nature of events occurring at the PM still largely remains a mystery. In stimulated BON cells, we used evanescent wave microscopy to study trajectories of granules shortly before their exocytoses, which provided a physical description of vesicle-PM interactions at an unprecedented level of detail, and directly lead to an original mechanistic model. In these cells, tethered (T), nonfusogenic, vesicles are prevented from converting to fusogenic, docked (D) ones in resting conditions. Upon elevation of calcium, T-vesicles perform a 21-nm step toward the PM to become D, and fuse approximately 3 s thereafter. Our ability to directly visualize different modes of PM-attachment paves the way for clarifying the exact role of various molecules implicated in attachment and priming of granules in future studies.

Published
2008
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3. Serotonin Secretion by Human Carcinoid BON Cells

Author

Erdem Karatekin, Viet Samuel Tran, Catherine Chapuis, Koulm Guillaumie, Sébastien Huet, A.M. Marion-Audibert, Claire Desnos, Sophie Cribier, Jean-Pierre Henry, François Darchen, Biologie cellulaire et moléculaire de la sécrétion (BCMS), Centre National de la Recherche Scientifique (CNRS), Department of Chemical Engineering, Columbia University [New York], Institut de Génétique et Développement de Rennes (IGDR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), European Molecular Biology Laboratory [Heidelberg] (EMBL), Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire de dynamique membranaire et maladies neurologiques (UMR 8192), Université Paris Descartes - Paris 5 (UPD5)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), Centre National de la Recherche Scientifique (CNRS)-Université Paris Descartes - Paris 5 (UPD5), Biologie cellulaire et moléculaire de la sécrétion ( BCMS ), Centre National de la Recherche Scientifique ( CNRS ), Institut de Génétique et Développement de Rennes ( IGDR ), Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -Centre National de la Recherche Scientifique ( CNRS ) -Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), European Molecular Biology Laboratory [Heidelberg] ( EMBL ), Université Pierre et Marie Curie - Paris 6 ( UPMC ), Laboratoire de dynamique membranaire et maladies neurologiques ( UMR 8192 ), and Université Paris Descartes - Paris 5 ( UPD5 ) -Centre National de la Recherche Scientifique ( CNRS )

Subjects
Serotonin, Carcinoid Tumor, [SDV.BC.BC]Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], Biology, General Biochemistry, Genetics and Molecular Biology, Exocytosis, Serotonin secretion, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, History and Philosophy of Science, Cell Line, Tumor, Muscarinic acetylcholine receptor, Enterochromaffin Cells, Humans, Secretion, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, General Neuroscience, Vesicle, [ SDV.BC.BC ] Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], Secretory Vesicle, Pancreatic Neoplasms, Digitonin, chemistry, Biochemistry, 030220 oncology & carcinogenesis, Enterochromaffin cell, Biophysics
Abstract

BON cells are human carcinoid cells that secrete serotonin (5-HT) and various peptides. Secretion of [(3)H]5-HT by cell cultures was investigated. Acetylcholine (Ach) stimulated secretion through a somatostatin-sensitive muscarinic pathway, whereas isoproterenol was inefficient. [(3)H]5-HT secretion also was induced by Ca(2+) in the presence of the ionophore A-23187 or after digitonin permeabilization. These two processes were insensitive to stomatostatin. Ba(2+) induced an efficient somatostatin-sensitive [(3)H]5-HT secretory response. Secretion also was analyzed at the single-cell level, using carbon fiber amperometry and evanescent-field fluorescence microscopy, after labeling the secretory vesicles by transfection of the cells with a NPY-GFP construct. Both techniques revealed slow kinetics of secretory responses, suggesting that ready-to-fuse vesicles do not accumulate in these cells. Single secretory vesicles were imaged either in resting conditions or after addition of Ca(2+) ions to digitonin-permeabilized cells. The three-dimensional movements of the vesicles before exocytosis were analyzed. The mean velocity of vesicles that released their content was lower than that of silent ones. Even in the case of mobile vesicles, exocytosis often was preceded by a period of arrest lasting at least 15 seconds, consistent with a docking/priming step.

Published
2004
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4. Rab27A and its effector MyRIP link secretory granules to F-actin and control their motion towards release sites

Author

Isabelle Fanget, Sébastien Huet, François Darchen, Christine Petit, Catherine Chapuis, Graça Raposo, Viet Samuel Tran, Sophie Cribier, Geneviève de Saint Basile, Gaël Ménasché, Aziz El-Amraoui, Claire Desnos, Jean-Sébastien Schonn, Jean-Pierre Henry, Biologie cellulaire et moléculaire de la sécrétion (BCMS), Centre National de la Recherche Scientifique (CNRS), Institut de biologie physico-chimique (IBPC), Génétique des Déficits sensoriels, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Compartimentation et dynamique cellulaires (CDC), Centre National de la Recherche Scientifique (CNRS)-Institut Curie-Université Pierre et Marie Curie - Paris 6 (UPMC), Inserm U429 (CHU Necker - Enfants Malades [AP-HP]), Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Necker - Enfants Malades [AP-HP], Laboratoire de biologie physico-chimique des protéines membranaires (LBPC-PM (UMR_7099)), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut de biologie physico-chimique (IBPC), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), J.-S. Schonn was supported by a fellowship from the Fondation de la Recherche Médicale, and S. Huet was supported by the Direction Générale de l’Armement. This work was supported by a grant from the Ministère de la Recherche (DRAB)., Centre National de la Recherche Scientifique (CNRS)-Institut Curie [Paris]-Université Pierre et Marie Curie - Paris 6 (UPMC), Developpement Normal et Pathologique du Système Immunitaire, Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Chaire Génétique et physiologie cellulaire, Collège de France (CdF (institution)), Institut de biologie physico-chimique (IBPC (FR_550)), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), J.-S. Schonn was supported by a fellowship from the Fondation de la Recherche Médicale, and S. Huet was supported by the Direction Générale de l'Armement. This work was supported by a grant from the Ministère de la Recherche (DRAB)., Chapuis, Catherine, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut Curie [Paris]-Centre National de la Recherche Scientifique (CNRS), Collège de France - Chaire Génétique et physiologie cellulaire, Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Biologie cellulaire et moléculaire de la sécrétion ( BCMS ), Centre National de la Recherche Scientifique ( CNRS ), Institut de Génétique et Développement de Rennes ( IGDR ), Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -Centre National de la Recherche Scientifique ( CNRS ) -Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), Institut Pasteur [Paris]-Centre National de la Recherche Scientifique ( CNRS ), Compartimentation et dynamique cellulaires ( CDC ), Centre National de la Recherche Scientifique ( CNRS ) -INSTITUT CURIE-Université Pierre et Marie Curie - Paris 6 ( UPMC ), Université Paris Descartes - Paris 5 ( UPD5 ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de biologie physico-chimique des protéines membranaires ( LBPC-PM ), and Université Paris Diderot - Paris 7 ( UPD7 ) -Institut de Biologie Physico-Chimique-Centre National de la Recherche Scientifique ( CNRS )

Subjects
Chromaffin Cells, [SDV]Life Sciences [q-bio], Rab27A, MyRIP, exocytosis, actin, neuroendocrine cell, [SDV.BC.BC]Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], PC12 Cells, rab27 GTP-Binding Proteins, 0302 clinical medicine, Depsipeptides, Myosin, 0303 health sciences, Secretory Vesicle, Cell biology, Actin Cytoskeleton, Melanophilin, Thiazolidines, endocrine system, Myosin Type V, macromolecular substances, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Biology, Peptides, Cyclic, Exocytosis, Article, 03 medical and health sciences, [SDV.BC.BC] Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], Animals, RAB27, Actin, 030304 developmental biology, Adaptor Proteins, Signal Transducing, Myosin Heavy Chains, Secretory Vesicles, [ SDV.BC.BC ] Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], Cell Biology, Actin cytoskeleton, Bridged Bicyclo Compounds, Heterocyclic, Actins, Rats, Microscopy, Electron, Thiazoles, rab GTP-Binding Proteins, Latrunculin, Cattle, Carrier Proteins, 030217 neurology & neurosurgery
Abstract

International audience; The GTPase Rab27A interacts with myosin-VIIa and myosin-Va via MyRIP or melanophilin and mediates melanosome binding to actin. Here we show that Rab27A and MyRIP are associated with secretory granules (SGs) in adrenal chromaffin cells and PC12 cells. Overexpression of Rab27A, GTPase-deficient Rab27A-Q78L, or MyRIP reduced secretory responses of PC12 cells. Amperometric recordings of single adrenal chromaffin cells revealed that Rab27A-Q78L and MyRIP reduced the sustained component of release. Moreover, these effects on secretion were partly suppressed by the actin-depolymerizing drug latrunculin but strengthened by jasplakinolide, which stabilizes the actin cortex. Finally, MyRIP and Rab27A-Q78L restricted the motion of SGs in the subplasmalemmal region of PC12 cells, as measured by evanescent-wave fluorescence microscopy. In contrast, the Rab27A-binding domain of MyRIP and a MyRIP construct that interacts with myosin-Va but not with actin increased the mobility of SGs. We propose that Rab27A and MyRIP link SGs to F-actin and control their motion toward release sites through the actin cortex.

Published
2003
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5. Analysis of Transient Behavior in Complex Trajectories: Application to Secretory Vesicle Dynamics

Author

Sophie Cribier, Viet Samuel Tran, Erdem Karatekin, Sébastien Huet, Isabelle Fanget, Jean-Pierre Henry, Biologie cellulaire et moléculaire de la sécrétion (BCMS), Centre National de la Recherche Scientifique (CNRS), Physico-chimie moléculaire des membranes biologiques (PCMMB), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), and Godard, Edith

Subjects
Physics, 0303 health sciences, Diffusion (acoustics), Movement, Secretory Vesicles, media_common.quotation_subject, Dynamics (mechanics), Biophysics, Motion (geometry), Curvature, Asymmetry, Displacement (vector), Cell Line, 03 medical and health sciences, 0302 clinical medicine, Microscopy, Fluorescence, Image Interpretation, Computer-Assisted, Trajectory, Humans, Transient (computer programming), Other, Biological system, 030217 neurology & neurosurgery, 030304 developmental biology, media_common
Abstract

Analysis of trajectories of dynamical biological objects, such as breeding ants or cell organelles, is essential to reveal the interactions they develop with their environments. Many previous works used a global characterization based on parameters calculated for entire trajectories. In cases where transient behavior was detected, this usually concerned only a particular type, such as confinement or directed motion. However, these approaches are not appropriate in situations in which the tracked objects may display many different types of transient motion. We have developed a method to exhaustively analyze different kinds of transient behavior that the tracked objects may exhibit. The method discriminates stalled periods, constrained and directed motions from random dynamics by evaluating the diffusion coefficient, the mean-square displacement curvature, and the trajectory asymmetry along individual trajectories. To detect transient motions of various durations, these parameters are calculated along trajectories using a rolling analysis window whose width is variable. The method was applied to the study of secretory vesicle dynamics in the subplasmalemmal region of human carcinoid BON cells. Analysis of transitions between transient motion periods, combined with plausible assumptions about the origin of each motion type, leads to a model of dynamical subplasmalemmal organization.

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