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Neubauer C, Kantnerová K, Lamothe A, Savarino J, Hilkert A, Juchelka D, Hinrichs KU, Elvert M, Heuer V, Elsner M, Bakkour R, Julien M, Öztoprak M, Schouten S, Hattori S, Dittmar T. Discovering Nature's Fingerprints: Isotope Ratio Analysis on Bioanalytical Mass Spectrometers. J Am Soc Mass Spectrom 2023; 34:525-537. [PMID: 36971362 DOI: 10.1021/jasms.2c00363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
For a generation or more, the mass spectrometry that developed at the frontier of molecular biology was worlds apart from isotope ratio mass spectrometry, a label-free approach done on optimized gas-source magnetic sector instruments. Recent studies show that electrospray-ionization Orbitraps and other mass spectrometers widely used in the life sciences can be fine-tuned for high-precision isotope ratio analysis. Since isotope patterns form everywhere in nature based on well-understood principles, intramolecular isotope measurements allow unique insights into a fascinating range of research topics. This Perspective introduces a wider readership to current topics in stable isotope research with the aim of discussing how soft-ionization mass spectrometry coupled with ultrahigh mass resolution can enable long-envisioned progress. We highlight novel prospects of observing isotopes in intact polar compounds and speculate on future directions of this adventure into the overlapping realms of biology, chemistry, and geology.
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Affiliation(s)
- Cajetan Neubauer
- University of Colorado Boulder & Institute for Arctic and Alpine Research (INSTAAR), Boulder, Colorado 80303, United States
| | - Kristýna Kantnerová
- University of Colorado Boulder & Institute for Arctic and Alpine Research (INSTAAR), Boulder, Colorado 80303, United States
| | - Alexis Lamothe
- University Grenoble Alpes, CNRS, IRD, INRAE, Grenoble-INP, IGE, Grenoble 38400, France
| | - Joel Savarino
- University Grenoble Alpes, CNRS, IRD, INRAE, Grenoble-INP, IGE, Grenoble 38400, France
| | | | | | - Kai-Uwe Hinrichs
- MARUM Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany
| | - Marcus Elvert
- MARUM Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany
| | - Verena Heuer
- MARUM Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany
| | - Martin Elsner
- Department of Chemistry, Technical University of Munich, D-85748 Garching, Germany
| | - Rani Bakkour
- Department of Chemistry, Technical University of Munich, D-85748 Garching, Germany
| | - Maxime Julien
- GFZ German Research Center for Geosciences, 14473 Potsdam, Germany
| | - Merve Öztoprak
- NIOZ Royal Netherlands Institute for Sea Research, Texel 1797 SZ, Netherlands
| | - Stefan Schouten
- NIOZ Royal Netherlands Institute for Sea Research, Texel 1797 SZ, Netherlands
| | - Shohei Hattori
- International Center for Isotope Effects Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210093, China
| | - Thorsten Dittmar
- Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, 26129 Oldenburg, Germany
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Julien M, Omorou A, Dufrost V, Foret T, Salignac S, Broseus J, Wahl D, Eschwège V, Zuily S. 150 - La cinétique des D-dimères pendant l'hospitalisation est un facteur pronostique majeur de décès chez les patients hospitalisés pour COVID-19. Rev Epidemiol Sante Publique 2022. [PMCID: PMC9340474 DOI: 10.1016/j.respe.2022.06.130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Contexte La tendance évolutive des D-dimères pourrait être un facteur prédictif de la gravité de cette maladie mais est très peu étudié. Cette étude avait pour objectif d'identifier des phénotypes biologiques d’évolution des D-dimères et leur valeur pronostique sur le risque de décès ou de thrombose chez les patients hospitalisés pour COVID-19. Méthodes Étude monocentrique incluant 270 patients hospitalisés pour COVID-19 au CHRU de Nancy du 21/02/20 au 12/05/20. Les données biologiques et cliniques ont été́ recueillies à l'aide des dossiers médicaux informatisés des patients. Le dosage des D-dimères plasmatiques mesurés par méthode immuno-enzymatique. Le critère de jugement principal était la mortalité toutes causes et le critère secondaire était la survenue d’événements thrombotiques. Nous avons utilisé le modèle conjoint à classes latentes qui permet de modéliser simultanément les trajectoires latentes de D-dimères et le risque de décès ou de thrombose. Résultats Trois types de trajectoires de D-dimères ont été identifiés : trajectoire 1) « Niveau initial élevé puis décroisant » (n=65, 24,1 %); trajectoire 2) « Niveau initial bas puis augmentation rapide » (n=18, 6,6 %); trajectoire 3) « Niveau initial modéré puis stable » (n=187, 69,3 %). Dans l'ensemble de l’échantillon les taux de décès et de thromboses étaient de 14,4 % (38/270) et 12,2 % (32/263) respectivement. Comparée à la trajectoire 3, les patients des trajectoires 1 et 2 avaient un risque de décès 3,6 (HR=3,6 [1,1–12,3], p=0,037) et 18,1 (HR=18,1 [4,3–76,2], p<0,0001) fois plus élevées respectivement. Le risque de thrombose n’était pas significativement différent entre les trois trajectoires. Conclusion Cette étude a montré qu'un niveau très élevé de D-dimères à l'admission ou un niveau bas mais avec une augmentation rapide durant l'hospitalisation sont des facteurs pronostiques important de la sévérité de la COVID-19. Un suivi rapproché de la cinétique des D-dimères, notamment dès les premiers jours d'hospitalisation devrait être renforcé chez ces patients. Déclaration de liens d'intérêts Les auteurs déclarent ne pas avoir de liens d'intérêts.
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Julien M, Liégeois M, Höhener P, Paneth P, Remaud GS. Intramolecular non-covalent isotope effects at natural abundance associated with the migration of paracetamol in solid matrices during liquid chromatography. J Chromatogr A 2021; 1639:461932. [PMID: 33535117 DOI: 10.1016/j.chroma.2021.461932] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 10/22/2022]
Abstract
Position-specific isotope analysis by Nuclear Magnetic Resonance spectrometry was employed to study the 13C intramolecular isotopic fractionation associated with the migration of organic substrates through different stationary phases chromatography columns. Liquid chromatography is often used to isolate compounds prior to their isotope analysis and this purification step potentially alters the isotopic composition of target compounds introducing a bias in the later measured data. Moreover, results from liquid chromatography can yield the sorption parameters needed in reactive transport models that predict the transport and fate of organic contaminants to in the environment. The aim of this study was to use intramolecular isotope analysis to study both 13C and 15N isotope effects associated with the elution of paracetamol (acetaminophen) through different stationary phases and to compare them to effects observed previously for vanillin. Results showed very different intramolecular isotope fractionation profiles depending on the chemical structure of the stationary phase. The data also demonstrate that both the amplitude and the distribution of measured isotope effects depend on the nature of the non-covalent interactions involved in the migration process. Results provided by theoretical calculation performed during this study also confirmed the direct link between observed intramolecular isotope fractionation and the nature of involved intermolecular interactions. It is concluded that the nature of the stationary phase through which the substrate passes has a major impact on the intramolecular isotopic composition of organic compounds isolated by chromatography methods..
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Affiliation(s)
- Maxime Julien
- Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ōokayama, Meguro-ku, Tokyo, 152-8551 Japan; Université de Nantes, CNRS, CEISAM UMR 6230, F-44000 Nantes, France.
| | | | - Patrick Höhener
- University of Aix-Marseille-CNRS, Laboratoire Chimie Environnement, UMR 7376, place Victor Hugo 3, 13331 Marseille, France
| | - Piotr Paneth
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Gérald S Remaud
- Université de Nantes, CNRS, CEISAM UMR 6230, F-44000 Nantes, France
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Julien M, Gori D, Höhener P, Robins RJ, Remaud GS. Intramolecular isotope effects during permanganate oxidation and acid hydrolysis of methyl tert-butyl ether. Chemosphere 2020; 248:125975. [PMID: 32007772 DOI: 10.1016/j.chemosphere.2020.125975] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 10/01/2019] [Accepted: 01/19/2020] [Indexed: 06/10/2023]
Abstract
Stable isotopes have been widely used to monitor remediation of environmental contaminants over the last decades. This approach gives a good mechanistic description of natural or assisted degradation of organic pollutants, such as methyl tert-butyl ether (MTBE). Since abiotic degradation seems to be the most promising assisted attenuation method, the isotopic fractionation associated with oxidation and hydrolysis processes need to be further investigated in order to understand better these processes and make their monitoring more efficient. In this study, position-specific isotope effects (PSIEs) associated with permanganate oxidation and acid hydrolysis of MTBE were determined using isotope ratio monitoring by 13C Nuclear Magnetic Resonance Spectrometry (irm-13C NMR) combined with isotope ratio monitoring by Mass Spectrometry (irm-MS). The use of this Position-Specific Isotopic Analysis (PSIA) method makes it possible to observe a specific normal isotope effect (IE) associated with each of these two abiotic degradation mechanisms. The present work demonstrates that the 13C isotope pattern of the main degradation product, tert-butyl alcohol (TBA), depends on the chemical reaction by which it is produced. Furthermore, this study also demonstrates that PSIA at natural abundance can give new insights into reaction mechanisms and that this methodology is very promising for the future of modeling the remediation of organic contaminants.
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Affiliation(s)
- Maxime Julien
- Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8503, Japan; EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 Rue de la Houssinière BP 92208, F-44322, Nantes, France.
| | - Didier Gori
- University of Aix-Marseille-CNRS, Laboratoire Chimie Environnement, UMR 7376, Place Victor Hugo 3, 13331 Marseille, France
| | - Patrick Höhener
- University of Aix-Marseille-CNRS, Laboratoire Chimie Environnement, UMR 7376, Place Victor Hugo 3, 13331 Marseille, France
| | - Richard J Robins
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 Rue de la Houssinière BP 92208, F-44322, Nantes, France
| | - Gérald S Remaud
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 Rue de la Houssinière BP 92208, F-44322, Nantes, France
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Robins RJ, Romek KM, Grand M, Nun P, Diomande D, Julien M, Remaud GS. Difficulties in Differentiating Natural from Synthetic Alkaloids by Isotope Ratio Monitoring using 13C Nuclear Magnetic Resonance Spectrometry. Planta Med 2018; 84:935-940. [PMID: 29653457 DOI: 10.1055/a-0601-7157] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Within the food and pharmaceutical industries, there is an increasing legislative requirement for the accurate labeling of the product's origin. A key feature of this is to indicate whether the product is of natural or synthetic origin. With reference to this context, we have investigated three alkaloids commonly exploited for human use: nicotine, atropine, and caffeine. We have measured by 13C nuclear magnetic resonance spectrometry the position-specific distribution of 13C at natural abundance within several samples of each of these target molecules. This technique is well suited to distinguishing between origins, as the distribution of the 13C isotope reflects the primary source of the carbon atoms and the process by which the molecule was (bio)synthesized. Our findings indicate that labeling can be misleading, especially in relation to a supplied compound being labeled as "synthetic" even though its 13C profile indicates a natural origin.
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Affiliation(s)
- Richard J Robins
- Elucidation of Biosynthesis by Isotopic Spectrometry Group, CEISAM, CNRS - University of Nantes UMR6230, Nantes, France
| | - Katarzyna M Romek
- Elucidation of Biosynthesis by Isotopic Spectrometry Group, CEISAM, CNRS - University of Nantes UMR6230, Nantes, France
- Ecosystem Physiology, University of Freiburg, Freiburg, Germany
| | - Mathilde Grand
- Elucidation of Biosynthesis by Isotopic Spectrometry Group, CEISAM, CNRS - University of Nantes UMR6230, Nantes, France
| | - Pierrick Nun
- Elucidation of Biosynthesis by Isotopic Spectrometry Group, CEISAM, CNRS - University of Nantes UMR6230, Nantes, France
| | - Didier Diomande
- Elucidation of Biosynthesis by Isotopic Spectrometry Group, CEISAM, CNRS - University of Nantes UMR6230, Nantes, France
- L'Université Félix Houphouët-Boigny, l'UFR Sciences des Structures de la Matière et de Technologie, Abidjan, Côte d'Ivoire
| | - Maxime Julien
- Elucidation of Biosynthesis by Isotopic Spectrometry Group, CEISAM, CNRS - University of Nantes UMR6230, Nantes, France
| | - Gérald S Remaud
- Elucidation of Biosynthesis by Isotopic Spectrometry Group, CEISAM, CNRS - University of Nantes UMR6230, Nantes, France
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Julien M, Gilbert A, Yamada K, Robins RJ, Höhener P, Yoshida N, Remaud GS. Expanded uncertainty associated with determination of isotope enrichment factors: Comparison of two point calculation and Rayleigh-plot. Talanta 2018; 176:367-373. [DOI: 10.1016/j.talanta.2017.08.038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 08/09/2017] [Accepted: 08/09/2017] [Indexed: 10/19/2022]
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Delaunay M, Cadranel J, Lusque A, Gounant V, Moro-Sibilot D, Dalle S, Leccia MT, Prévot G, Milia J, Julien M, Meyer N. Caractéristiques des pneumopathies interstitielles diffuses survenant chez des patients traités par les inhibiteurs des points de contrôle immunitaire. Ann Dermatol Venereol 2017. [DOI: 10.1016/j.annder.2017.09.120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Julien M, Höhener P, Robins RJ, Parinet J, Remaud GS. Position-Specific 13C Fractionation during Liquid–Vapor Transition Correlated to the Strength of Intermolecular Interaction in the Liquid Phase. J Phys Chem B 2017; 121:5810-5817. [DOI: 10.1021/acs.jpcb.7b00971] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Maxime Julien
- EBSI
Team, CEISAM, University of Nantes−CNRS UMR 6230, 2 rue de la
Houssinière BP 92208, F-44322 Nantes, France
| | - Patrick Höhener
- Aix Marseille
Univ, CNRS UMR 7376, Laboratoire Chimie Environnement, 3 place Victor Hugo, F-13331 Marseille, France
| | - Richard J. Robins
- EBSI
Team, CEISAM, University of Nantes−CNRS UMR 6230, 2 rue de la
Houssinière BP 92208, F-44322 Nantes, France
| | - Julien Parinet
- Aix Marseille
Univ, CNRS UMR 7376, Laboratoire Chimie Environnement, 3 place Victor Hugo, F-13331 Marseille, France
| | - Gérald S. Remaud
- EBSI
Team, CEISAM, University of Nantes−CNRS UMR 6230, 2 rue de la
Houssinière BP 92208, F-44322 Nantes, France
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Affiliation(s)
- M. Julien
- Fives-Cail Babcock, 80, Rue Emile-Zola, 93 La Courneuve, France
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Oka Y, Wakabayashi H, An S, Suzuki I, Teschendorff V, Barsoum Wahba A, Caldarola L, Ferranti P, Mitzel F, A. Evans V, V. Chester C, O. Chester R, Bierman SR, A. Rehbein D, W. Carlson R, MacDonald PE, Weisman J, Julien M, Shure K. Authors. NUCL TECHNOL 2017. [DOI: 10.13182/nt76-a31664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Wahl G, Borrmann M, Böse K, Gräfe L, Julien M. Kopfschmerzen bei Einschülern, Drittklässlern und Sechstklässlern in Sachsen-Anhalt: Häufigkeit nach Elternauskunft und Selbstauskunft und assoziierte Untersuchungs- und Befragungsbefunde. Gesundheitswesen 2017. [DOI: 10.1055/s-0037-1601998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- G Wahl
- Landesamt für Verbraucherschutz Sachsen-Anhalt, Magdeburg
| | - M Borrmann
- Landesamt für Verbraucherschutz Sachsen-Anhalt, Magdeburg
| | - K Böse
- Landesamt für Verbraucherschutz Sachsen-Anhalt, Magdeburg
| | - L Gräfe
- Landesamt für Verbraucherschutz Sachsen-Anhalt, Magdeburg
| | - M Julien
- Landesamt für Verbraucherschutz Sachsen-Anhalt, Magdeburg
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Höhener P, Li ZM, Julien M, Nun P, Robins RJ, Remaud GS. Simulating Stable Isotope Ratios in Plumes of Groundwater Pollutants with BIOSCREEN-AT-ISO. Ground Water 2017; 55:261-267. [PMID: 27696411 DOI: 10.1111/gwat.12472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 09/01/2016] [Indexed: 05/22/2023]
Abstract
BIOSCREEN is a well-known simple tool for evaluating the transport of dissolved contaminants in groundwater, ideal for rapid screening and teaching. This work extends the BIOSCREEN model for the calculation of stable isotope ratios in contaminants. A three-dimensional exact solution of the reactive transport from a patch source, accounting for fractionation by first-order decay and/or sorption, is used. The results match those from a previously published isotope model but are much simpler to obtain. Two different isotopes may be computed, and dual isotope plots can be viewed. The dual isotope assessment is a rapidly emerging new approach for identifying process mechanisms in aquifers. Furthermore, deviations of isotope ratios at specific reactive positions with respect to "bulk" ratios in the whole compound can be simulated. This model is named BIOSCREEN-AT-ISO and will be downloadable from the journal homepage.
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Affiliation(s)
| | - Zhi M Li
- Laboratoire Chimie Environnement, Aix Marseille University, CNRS UMR 7376, Marseille, F-13331, France
| | - Maxime Julien
- EBSI Team, CEISAM, Nantes University, CNRS UMR 6230, Nantes, F-44322, France
| | - Pierrick Nun
- EBSI Team, CEISAM, Nantes University, CNRS UMR 6230, Nantes, F-44322, France
| | - Richard J Robins
- EBSI Team, CEISAM, Nantes University, CNRS UMR 6230, Nantes, F-44322, France
| | - Gérald S Remaud
- EBSI Team, CEISAM, Nantes University, CNRS UMR 6230, Nantes, F-44322, France
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Allas S, Delale T, Ngo N, Julien M, Sahakian P, Ritter J, Abribat T, van der Lely AJ. Safety, tolerability, pharmacokinetics and pharmacodynamics of AZP-531, a first-in-class analogue of unacylated ghrelin, in healthy and overweight/obese subjects and subjects with type 2 diabetes. Diabetes Obes Metab 2016; 18:868-74. [PMID: 27063928 DOI: 10.1111/dom.12675] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 04/05/2016] [Accepted: 02/24/2016] [Indexed: 01/05/2023]
Abstract
AIM To explore the safety, pharmacokinetics and pharmacodynamics in humans of the unacylated ghrelin analogue AZP-531, designed to improve glycaemic control and reduce weight. METHODS Assessments, including glucose measurements, were performed in a three-part randomized study. In Part A, healthy subjects [n = 44, age 18-50 years, body mass index (BMI) 20-28 kg/m(2) ] received a single subcutaneous dose of 0.3, 3, 15, 30, 60 or 120 µg/kg AZP-531 or placebo. In Part B, overweight/obese subjects (n = 32, age 18-65 years, BMI 28-38 kg/m(2) ) and in Part C, patients with type 2 diabetes [T2D; n = 36, age 18-65 years, BMI 20-40 kg/m(2) , glycated haemoglobin (HbA1c) 7-10%] received AZP-531 or placebo for 14 days (daily doses of 3, 15, 30 or 60 µg/kg and 15, 2 × 30 or 60 µg/kg, respectively). RESULTS AZP-531 was well tolerated. Single- and multiple-dose pharmokinetic variables were similar. Maximum AZP-531 concentrations were typically reached at 1 h post-dose. Observed maximum concentration (Cmax ) and area under the curve were dose-proportional. The mean terminal half-life (t1/2 ) was 2-3 h. In Part B, AZP-531 doses of ≥15 µg/kg significantly improved glucose concentrations, without increasing insulin levels, suggesting an insulin-sensitizing effect. AZP-531 decreased mean body weight by 2.6 kg (vs 0.8 kg for placebo). In Part C, glucose variables improved in all groups, including placebo, suggesting a study effect in uncontrolled patients at baseline. Notwithstanding, AZP-531 60 µg/kg reduced HbA1c by 0.4% (vs 0.2% for placebo) and body weight by 2.1 kg (vs 1.3 kg for placebo). CONCLUSIONS AZP-531 was well tolerated in this first-in-human study. Its pharmacokinetic profile, suitable for once-daily dosing, and metabolic effects support further clinical development for T2D.
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Affiliation(s)
- S Allas
- Alizé Pharma, Ecully, France
| | | | - N Ngo
- Quintiles Early Clinical Development PK Department, Overland Park, KS, USA
| | | | | | - J Ritter
- Phase 1 Quintiles Unit, London, UK
| | | | - A J van der Lely
- Department of Medicine, Erasmus University Medical Centre, Rotterdam, The Netherlands
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Kuppens RJ, Diène G, Bakker NE, Molinas C, Faye S, Nicolino M, Bernoux D, Delhanty PJD, van der Lely AJ, Allas S, Julien M, Delale T, Tauber M, Hokken-Koelega ACS. Elevated ratio of acylated to unacylated ghrelin in children and young adults with Prader-Willi syndrome. Endocrine 2015; 50:633-42. [PMID: 25989955 PMCID: PMC4662713 DOI: 10.1007/s12020-015-0614-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 04/21/2015] [Indexed: 01/13/2023]
Abstract
Prader-Willi syndrome (PWS) is characterized by a switch from failure to thrive to excessive weight gain and hyperphagia in early childhood. Hyperghrelinemia may be involved in the underlying mechanisms of the switch. The purpose of this study is to evaluate acylated ghrelin (AG) and unacylated ghrelin (UAG) levels in PWS and investigate their associations with hyperphagia. This is a cross-sectional clinical study conducted in three PWS expert centers in the Netherlands and France. Levels of AG and UAG and the AG/UAG ratio were determined in 138 patients with PWS (0.2-29.4 years) and compared with 50 age-matched obese subjects (4.3-16.9 years) and 39 healthy controls (0.8-28.6 years). AEBSF was used to inhibit deacylation of AG. As a group, PWS patients had higher AG but similar UAG levels as healthy controls (AG 129.1 vs 82.4 pg/ml, p = 0.016; UAG 135.3 vs 157.3 pg/ml, resp.), resulting in a significantly higher AG/UAG ratio (1.00 vs 0.61, p = 0.001, resp.). Obese subjects had significantly lower AG and UAG levels than PWS and controls (40.3 and 35.3 pg/ml, resp.), but also a high AG/UAG ratio (1.16). The reason for the higher AG/UAG ratio in PWS and obese was, however, completely different, as PWS had a high AG and obese a very low UAG. PWS patients without weight gain or hyperphagia had a similar AG/UAG ratio as age-matched controls, in contrast to those with weight gain and/or hyperphagia who had an elevated AG/UAG ratio. The switch to excessive weight gain in PWS seems to coincide with an increase in the AG/UAG ratio, even prior to the start of hyperphagia.
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Affiliation(s)
- R J Kuppens
- Dutch Growth Research Foundation, Westzeedijk 106, 3016 AH, Rotterdam, The Netherlands.
- Department of Pediatrics, Subdivision of Endocrinology, Erasmus University Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands.
| | - G Diène
- Unité D'endocrinologie, Obésité, Maladies Osseuses, Génétique et Gynécologie Médicale, Centre de Référence du Syndrome de Prader-Willi, Hôpital des enfants, Toulouse, France
| | - N E Bakker
- Dutch Growth Research Foundation, Westzeedijk 106, 3016 AH, Rotterdam, The Netherlands
- Department of Pediatrics, Subdivision of Endocrinology, Erasmus University Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands
| | - C Molinas
- Unité D'endocrinologie, Obésité, Maladies Osseuses, Génétique et Gynécologie Médicale, Centre de Référence du Syndrome de Prader-Willi, Hôpital des enfants, Toulouse, France
- Axe pédiatrique du CIC 9302/INSERM. Hôpital des enfants, Toulouse, France
| | - S Faye
- Unité D'endocrinologie, Obésité, Maladies Osseuses, Génétique et Gynécologie Médicale, Centre de Référence du Syndrome de Prader-Willi, Hôpital des enfants, Toulouse, France
| | - M Nicolino
- Division of Pediatric Endocrinology, Hôpital Femme-Mère-Enfant, University of Lyon, Bron/Lyon, France
| | - D Bernoux
- Division of Pediatric Endocrinology, Hôpital Femme-Mère-Enfant, University of Lyon, Bron/Lyon, France
| | - P J D Delhanty
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - A J van der Lely
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - S Allas
- Alizé Pharma, 69130, Ecully, France
| | - M Julien
- Alizé Pharma, 69130, Ecully, France
| | - T Delale
- Alizé Pharma, 69130, Ecully, France
| | - M Tauber
- Unité D'endocrinologie, Obésité, Maladies Osseuses, Génétique et Gynécologie Médicale, Centre de Référence du Syndrome de Prader-Willi, Hôpital des enfants, Toulouse, France
- INSERM U1043, Centre de Physiopathologie de Toulouse Purpan, Université Paul Sabatier, Toulouse, France
| | - A C S Hokken-Koelega
- Dutch Growth Research Foundation, Westzeedijk 106, 3016 AH, Rotterdam, The Netherlands
- Department of Pediatrics, Subdivision of Endocrinology, Erasmus University Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands
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Julien M, Nun P, Robins RJ, Remaud GS, Parinet J, Höhener P. Insights into Mechanistic Models for Evaporation of Organic Liquids in the Environment Obtained by Position-Specific Carbon Isotope Analysis. Environ Sci Technol 2015; 49:12782-8. [PMID: 26443423 DOI: 10.1021/acs.est.5b03280] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Position-specific isotope effects (PSIEs) have been measured by isotope ratio monitoring (13)C nuclear magnetic resonance spectrometry during the evaporation of 10 liquids of different polarities under 4 evaporation modes (passive evaporation, air-vented evaporation, low pressure evaporation, distillation). The observed effects are used to assess the validity of the Craig-Gordon isotope model for organic liquids. For seven liquids the overall isotope effect (IE) includes a vapor-liquid contribution that is strongly position-specific in polar compounds but less so in apolar compounds and a diffusive IE that is not position-specific, except in the alcohols, ethanol and propan-1-ol. The diffusive IE is diminished under forced evaporation. The position-specific isotope pattern created by liquid-vapor IEs is manifest in five liquids, which have an air-side limitation for volatilization. For the alcohols, undefined processes in the liquid phase create additional PSIEs. Three other liquids with limitations on the liquid side have a lower, highly position-specific, bulk diffusive IE. It is concluded that evaporation of organic pollutants creates unique position-specific isotope patterns that may be used to assess the progress of remediation or natural attenuation of pollution and that the Craig-Gordon isotope model is valid for the volatilization of nonpolar organic liquids with air-side limitation of the volatilization rate.
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Affiliation(s)
- Maxime Julien
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230 , 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Pierrick Nun
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230 , 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Richard J Robins
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230 , 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Gérald S Remaud
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230 , 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Julien Parinet
- Laboratoire Chimie Environnement, University of Aix-Marseille-CNRS FRE 3416 , place Victor Hugo 3, F-13331 Marseille, France
| | - Patrick Höhener
- Laboratoire Chimie Environnement, University of Aix-Marseille-CNRS FRE 3416 , place Victor Hugo 3, F-13331 Marseille, France
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Julien M, Nun P, Höhener P, Parinet J, Robins RJ, Remaud GS. Enhanced forensic discrimination of pollutants by position-specific isotope analysis using isotope ratio monitoring by (13)C nuclear magnetic resonance spectrometry. Talanta 2015; 147:383-9. [PMID: 26592622 DOI: 10.1016/j.talanta.2015.10.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 09/30/2015] [Accepted: 10/04/2015] [Indexed: 12/31/2022]
Abstract
In forensic environmental investigations the main issue concerns the inference of the original source of the pollutant for determining the liable party. Isotope measurements in geochemistry, combined with complimentary techniques for contaminant identification, have contributed significantly to source determination at polluted sites. In this work we have determined the intramolecular (13)C profiles of several molecules well-known as pollutants. By giving additional analytical parameters, position-specific isotope analysis performed by isotope ratio monitoring by (13)C nuclear magnetic resonance (irm-(13)C NMR) spectrometry gives new information to help in answering the major question: what is the origin of the detected contaminant? We have shown that isotope profiling of the core of a molecule reveals both the raw materials and the process used in its manufacture. It also can reveal processes occurring between the contamination site 'source' and the sampling site. Thus, irm-(13)C NMR is shown to be a very good complement to compound-specific isotope analysis currently performed by mass spectrometry for assessing polluted sites involving substantial spills of pollutant.
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Affiliation(s)
- Maxime Julien
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Pierrick Nun
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Patrick Höhener
- University of Aix-Marseille-CNRS, Laboratoire Chimie Environnement FRE 3416, Place Victor Hugo 3, 13331 Marseille, France
| | - Julien Parinet
- University of Aix-Marseille-CNRS, Laboratoire Chimie Environnement FRE 3416, Place Victor Hugo 3, 13331 Marseille, France
| | - Richard J Robins
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Gérald S Remaud
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière BP 92208, F-44322 Nantes, France.
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Julien M, Parinet J, Nun P, Bayle K, Höhener P, Robins RJ, Remaud GS. Fractionation in position-specific isotope composition during vaporization of environmental pollutants measured with isotope ratio monitoring by ¹³C nuclear magnetic resonance spectrometry. Environ Pollut 2015; 205:299-306. [PMID: 26123718 DOI: 10.1016/j.envpol.2015.05.047] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 05/19/2015] [Accepted: 05/22/2015] [Indexed: 05/14/2023]
Abstract
Isotopic fractionation of pollutants in terrestrial or aqueous environments is a well-recognized means by which to track different processes during remediation. As a complement to the common practice of measuring the change in isotope ratio for the whole molecule using isotope ratio monitoring by mass spectrometry (irm-MS), position-specific isotope analysis (PSIA) can provide further information that can be exploited to investigate source and remediation of soil and water pollutants. Position-specific fractionation originates from either degradative or partitioning processes. We show that isotope ratio monitoring by (13)C NMR (irm-(13)C NMR) spectrometry can be effectively applied to methyl tert-butylether, toluene, ethanol and trichloroethene to obtain this position-specific data for partitioning. It is found that each compound exhibits characteristic position-specific isotope fractionation patterns, and that these are modulated by the type of evaporative process occurring. Such data should help refine models of how remediation is taking place, hence back-tracking to identify pollutant sources.
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Affiliation(s)
- Maxime Julien
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Julien Parinet
- University of Aix-Marseille-CNRS, Laboratoire Chimie Environnement FRE 3416, Place Victor Hugo 3, 13331 Marseille, France
| | - Pierrick Nun
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Kevin Bayle
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Patrick Höhener
- University of Aix-Marseille-CNRS, Laboratoire Chimie Environnement FRE 3416, Place Victor Hugo 3, 13331 Marseille, France
| | - Richard J Robins
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Gérald S Remaud
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière BP 92208, F-44322 Nantes, France.
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Bayle K, Julien M, Remaud GS, Akoka S. Suppression of radiation damping for high precision quantitative NMR. J Magn Reson 2015; 259:121-125. [PMID: 26319280 DOI: 10.1016/j.jmr.2015.08.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 08/10/2015] [Accepted: 08/12/2015] [Indexed: 06/04/2023]
Abstract
True quantitative analysis of concentrated samples by (1)H NMR is made very difficult by Radiation Damping. A novel NMR sequence (inspired by the WET NMR sequence and by Outer Volume Saturation methods) is therefore proposed to suppress this phenomenon by reducing the spatial area and consequently the number of spins contributing to the signal detected. The size of the detected volume can be easily chosen in a large range and line shape distortions are avoided thanks to a uniform signal suppression of the outer volume. Composition of a mixture can as a result be determined with very high accuracy (precision and trueness) at the per mille level whatever the concentrations and without hardware modification.
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Affiliation(s)
- Kevin Bayle
- EBSI team, Interdisciplinary Chemistry: Synthesis, Analysis, Modeling (CEISAM), University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière, BP 92208, F-44322 Nantes cedex 3, France
| | - Maxime Julien
- EBSI team, Interdisciplinary Chemistry: Synthesis, Analysis, Modeling (CEISAM), University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière, BP 92208, F-44322 Nantes cedex 3, France
| | - Gérald S Remaud
- EBSI team, Interdisciplinary Chemistry: Synthesis, Analysis, Modeling (CEISAM), University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière, BP 92208, F-44322 Nantes cedex 3, France
| | - Serge Akoka
- EBSI team, Interdisciplinary Chemistry: Synthesis, Analysis, Modeling (CEISAM), University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière, BP 92208, F-44322 Nantes cedex 3, France.
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Parinet J, Julien M, Nun P, Robins RJ, Remaud G, Höhener P. Predicting equilibrium vapour pressure isotope effects by using artificial neural networks or multi-linear regression - A quantitative structure property relationship approach. Chemosphere 2015; 134:521-527. [PMID: 25559176 DOI: 10.1016/j.chemosphere.2014.10.079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 10/13/2014] [Accepted: 10/19/2014] [Indexed: 06/04/2023]
Abstract
We aim at predicting the effect of structure and isotopic substitutions on the equilibrium vapour pressure isotope effect of various organic compounds (alcohols, acids, alkanes, alkenes and aromatics) at intermediate temperatures. We attempt to explore quantitative structure property relationships by using artificial neural networks (ANN); the multi-layer perceptron (MLP) and compare the performances of it with multi-linear regression (MLR). These approaches are based on the relationship between the molecular structure (organic chain, polar functions, type of functions, type of isotope involved) of the organic compounds, and their equilibrium vapour pressure. A data set of 130 equilibrium vapour pressure isotope effects was used: 112 were used in the training set and the remaining 18 were used for the test/validation dataset. Two sets of descriptors were tested, a set with all the descriptors: number of(12)C, (13)C, (16)O, (18)O, (1)H, (2)H, OH functions, OD functions, CO functions, Connolly Solvent Accessible Surface Area (CSA) and temperature and a reduced set of descriptors. The dependent variable (the output) is the natural logarithm of the ratios of vapour pressures (ln R), expressed as light/heavy as in classical literature. Since the database is rather small, the leave-one-out procedure was used to validate both models. Considering higher determination coefficients and lower error values, it is concluded that the multi-layer perceptron provided better results compared to multi-linear regression. The stepwise regression procedure is a useful tool to reduce the number of descriptors. To our knowledge, a Quantitative Structure Property Relationship (QSPR) approach for isotopic studies is novel.
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Affiliation(s)
- Julien Parinet
- Aix-Marseille Université, Laboratoire Chimie Environnement, FRE 3416-CNRS, Marseille, France
| | - Maxime Julien
- Université de Nantes, Chimie et Interdisciplinarité: Synthèse, Analyse et Modélisation, UMR 6230-CNRS, Nantes, France
| | - Pierrick Nun
- Université de Nantes, Chimie et Interdisciplinarité: Synthèse, Analyse et Modélisation, UMR 6230-CNRS, Nantes, France
| | - Richard J Robins
- Université de Nantes, Chimie et Interdisciplinarité: Synthèse, Analyse et Modélisation, UMR 6230-CNRS, Nantes, France
| | - Gerald Remaud
- Université de Nantes, Chimie et Interdisciplinarité: Synthèse, Analyse et Modélisation, UMR 6230-CNRS, Nantes, France
| | - Patrick Höhener
- Aix-Marseille Université, Laboratoire Chimie Environnement, FRE 3416-CNRS, Marseille, France.
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Julien M, Meunier B, Retornaz F, Costello R, Mancini J, Mazodier K, Jean R, Durand J, Kaplanski G, Chiche L. Prise en charge des gammapathies monoclonales dépistées en médecine générale : étude des pratiques en médecine interne. Rev Med Interne 2015. [DOI: 10.1016/j.revmed.2015.03.283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Wahl G, Julien M. Subjektive Gesundheit und gesundheitsrelevantes Verhalten von Sechstklässlern in Sachsen-Anhalt: ein Survey der Gesundheitsberichterstattung des Landes. Gesundheitswesen 2015. [DOI: 10.1055/s-0035-1546929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Wahl G, Borrmann M, Julien M, Böse K, Gräfe L, Oppermann H. Neue Instrumente der Kinder- und Jugend-Gesundheitsberichterstattung in Sachsen-Anhalt. Gesundheitswesen 2014. [DOI: 10.1055/s-0034-1371599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Romek KM, Julien M, Frasquet-Darrieux M, Tea I, Antheaume I, Hankard R, Robins RJ. Human baby hair amino acid natural abundance 15N-isotope values are not related to the 15N-isotope values of amino acids in mother’s breast milk protein. Amino Acids 2013; 45:1365-72. [DOI: 10.1007/s00726-013-1597-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 09/13/2013] [Indexed: 11/24/2022]
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Tea I, Le Guennec A, Frasquet-Darrieux M, Julien M, Romek K, Antheaume I, Hankard R, Robins RJ. Simultaneous determination of natural-abundance δ15N values and quantities of individual amino acids in proteins from milk of lactating women and from infant hair using gas chromatography/isotope ratio mass spectrometry. Rapid Commun Mass Spectrom 2013; 27:1345-1353. [PMID: 23681812 DOI: 10.1002/rcm.6582] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/15/2013] [Accepted: 03/27/2013] [Indexed: 06/02/2023]
Abstract
RATIONALE In isotope tracer experiments used in nutritional studies, it is frequently desirable both to determine the (15)N/(14)N ratios of target compounds and to quantify these compounds. This report shows how this can be achieved in a single chromatographic run for protein amino acids using an isotope ratio mass spectrometer. METHODS Protein hydrolysis by acidic digestion was used to release amino acids, which were then derivatized as their N-pivaloyl-O-isopropyl esters. Suitable conditions for sample preparation were established for both hair and milk proteins. The N-pivaloyl-O-isopropyl esters of amino acids were separated by gas chromatography (GC) on a 60 m ZB-WAX column linked via a combustion interface to an isotope ratio mass spectrometer. The (15)N/(14)N ratios were obtained from the m/z 28, 29 and 30 peak intensities and the quantities from the Area All (Vs) integrated peak areas. RESULTS It is shown from a five-point calibration curve that both parameters can be measured reliably within the range of 1.0 to 2.0 mg/mL for the major amino acids derived from the hydrolysis of human maternal milk or hair samples. The method was validated in terms of inter-day and inter-user repeatability for both parameters for 14 amino acids. The amino acid percentage composition showed a good correlation with literature values. The method was applied to determine the variability in a population of lactating mothers and their infants. CONCLUSIONS It has been established that δ(15)N values can be simultaneously determined for a complex mixture of amino acids at variable concentrations. It is shown that the percentage composition obtained correlates well with that obtained by calculation from the protein composition or from literature values. This procedure should provide a significant saving in analysis time, especially in those cases where the GC run-time is necessarily long. It allows the satisfactory determination of the variation within a sample population.
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Affiliation(s)
- Illa Tea
- Elucidation of Biosynthesis by Isotopic Spectrometry Group, CEISAM, LUNAM Université, University of Nantes-CNRS UMR6230, 2 rue de la Houssinière, BP 92208, F-44322 Nantes, France.
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Khoshniat S, Bourgine A, Julien M, Petit M, Pilet P, Rouillon T, Masson M, Gatius M, Weiss P, Guicheux J, Beck L. Phosphate-dependent stimulation of MGP and OPN expression in osteoblasts via the ERK1/2 pathway is modulated by calcium. Bone 2011; 48:894-902. [PMID: 21147284 DOI: 10.1016/j.bone.2010.12.002] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 12/01/2010] [Accepted: 12/02/2010] [Indexed: 12/31/2022]
Abstract
Inorganic phosphate (Pi) acts as a signaling molecule in bone-forming cells, affecting cell functions and gene expression. Particularly, Pi stimulates the expression of mineralization-associated genes such as matrix gla protein (MGP) and osteopontin (OPN) through the ERK1/2 pathway. With respect to the presence of elevated extracellular calcium and Pi levels during bone remodeling, we questioned whether calcium might play a role in the Pi-dependent effects in osteoblasts. We first showed by Western blot and real-time PCR that the concomitant presence of 10 mM Pi and 1.8 mM calcium is required to stimulate ERK1/2 phosphorylation and MGP/OPN genes expression. The mechanisms involved in the cellular effects of calcium in the presence of Pi were subsequently examined. Firstly, the use of the calcium-sensing receptor (CaSR) agonist gadolinium and the G-protein inhibitor pertussis toxin enabled us to determine that a CaSR mechanism is not involved in the Pi and calcium mediated cellular effects. By transmission electron microscopy, we next demonstrated that adding 10mM Pi to the culture medium containing 1.8mM calcium led to the formation calcium phosphate precipitates (CaPp). Moreover, treatment of osteoblasts with exogenous pre-synthesized CaPp stimulated ERK1/2 phosphorylation and MGP/OPN genes expression. In spite of high extracellular calcium and Pi concentrations, this stimulation was blunted in the presence of phosphocitrate, an inhibitor of crystal formation. Finally, we showed that despite that CaPp are not endocytosed, their effect on ERK1/2 phosphorylation and MGP/OPN genes expression were dependent on lipid rafts integrity. In summary, we showed that calcium is required for Pi-dependent ERK1/2 phosphorylation and regulation of mineralization-associated genes in osteoblasts and that its effect could originate from extracellular-related effects of CaPp that are dependent on the integrity of lipid rafts.
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Affiliation(s)
- S Khoshniat
- Group STEP Skeletal Tissue Engineering and Physiopathology, Centre for Osteoarticular and Dental Tissue Engineering (LIOAD), INSERM, U791, Nantes, F-44042, France
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Julien M, Yann B, Philippe LF, Engin Y. 208 Assessment of teamwork by self-employed health professionals in the management of type 2 diabetes patients: the ASALEE project. BMJ Qual Saf 2010. [DOI: 10.1136/qshc.2010.041624.83] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Julien M. Plant biology and other issues that relate to the management of water hyacinth: a global perspective with focus on Europe1. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1365-2338.2008.01267.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Taksin L, Mallick S, Frachet O, Julien M, Lepennec V, Ficheux M, Bensadoun H. [Mycotic aneurysm and renal transplant. A case report]. Prog Urol 2008; 19:149-52. [PMID: 19168023 DOI: 10.1016/j.purol.2008.10.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Revised: 10/07/2008] [Accepted: 10/20/2008] [Indexed: 12/27/2022]
Abstract
The arterial aneurysm secondary to Candida is a rare but frightening complication of renal transplant. We report the case of a 58-year-old patient who developed an arterial aneurysm secondary to a Candida infection in 3 weeks of a third renal transplant. Candida albicans was isolated from the preservation solution. The treatment consisted of a transplant nephrectomy, aneurysm excision and an iliac bypass with cryopreserved iliac homograft. All of bacteriologic culture was positive for Candida. The positive bacteriologic culture for Candida in preservation solution requires antifongic treatment. In case of arterial aneurysm, a surgical treatment is necessary but majority of kidney transplant had to be removed.
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Affiliation(s)
- L Taksin
- Service d'urologie, CHU Côte-de-Nacre, avenue Côte-de-Nacre, 14000 Caen, France.
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Chautard J, Julien M. [Ruptured infra-renal abdominal aortic aneurysm]. J Chir (Paris) 2006; 143:173-7. [PMID: 16888604 DOI: 10.1016/s0021-7697(06)73647-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Affiliation(s)
- J Chautard
- Fédération de Chirurgie Viscérale et Digestive, CHU Côte de Nacre - Caen.
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Ancelle-Park R, Seradour B, Patty A, Julien M, Bloch J. Results of the new french breast cancer screening programme for year 2003. EJC Suppl 2006. [DOI: 10.1016/s1359-6349(06)80062-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Gadoury MA, Schwartzman K, Rouleau M, Maltais F, Julien M, Beaupré A, Renzi P, Bégin R, Nault D, Bourbeau J. Self-management reduces both short- and long-term hospitalisation in COPD. Eur Respir J 2005; 26:853-7. [PMID: 16264046 DOI: 10.1183/09031936.05.00093204] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The aim of the present study was to assess the long-term impact on hospitalisation of a self-management programme for chronic obstructive pulmonary disease (COPD) patients. A multicentre, randomised clinical trial was carried out involving 191 COPD patients from seven hospitals. Patients who had one or more hospitalisations in the year preceding study enrolment were assigned to a self-management programme "Living Well with COPD(TM)" or to standard care. Hospitalisations from all causes were the primary outcome and were documented from the provincial hospitalisation database; emergency visits were recorded from the provincial health insurance database. Most patients were elderly, not highly educated, had advanced COPD (reflected by a mean forced expiratory volume in one second of 1 L), and almost half reported a dyspnoea score of 5/5 (modified Medical Research Council). At 2 years, there was a statistically significant and clinically relevant reduction in all-cause hospitalisations of 26.9% and in all-cause emergency visits of 21.1% in the intervention group as compared to the standard-care group. After adjustment for the self-management intervention effect, the predictive factors for reduced hospitalisations included younger age, sex (female), higher education, increased health status and exercise capacity. In conclusion, in this study, patients with chronic obstructive pulmonary disease who received educational intervention with supervision and support based on disease-specific self-management maintained a significant reduction in hospitalisations after a 2-year period.
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Affiliation(s)
- M-A Gadoury
- Respiratory Epidemiology and Clinical Research Unit, 3650 St Urbain Street, Montréal, Québec, H2X 2P4, Canada
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Laurin C, Lavoie KL, Bacon S, Stébenne PR, Dupuis G, Cartier A, Lacoste G, Julien M, Labrecque M. SEX DIFFERENCES IN THE PREVALENCE OF PSYCHIATRIC DISORDERS AND PSYCHOLOGICAL DISTRESS IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE IN A CANADIAN SAMPLE. Chest 2005. [DOI: 10.1378/chest.128.4_meetingabstracts.265s-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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33
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Magne D, Julien M, Vinatier C, Merhi-Soussi F, Weiss P, Guicheux J. Cartilage formation in growth plate and arteries: from physiology to pathology. Bioessays 2005; 27:708-16. [PMID: 15954094 DOI: 10.1002/bies.20254] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Vascular calcifications are the consequence of several pathological conditions such as atherosclerosis, diabetes, hypercholesterolemia and chronic renal insufficiency. They are associated with risks of amputation, ischemic heart disease, stroke and increased mortality. A growing body of evidence indicates that vascular smooth muscle cells (VSMCs) undergo chondrogenic commitment eventually leading to vascular calcification, by mechanisms similar to those governing ossification in the cartilage growth plate. Our knowledge of the formation of cartilage growth plate can therefore help us to understand why and how arteries calcify and, consequently, develop new therapeutic strategies. Reciprocally, thorough consideration of the events leading to ectopic chondrocyte differentiation appears crucial to further increase our understanding of growth plate formation. In this context, we will review the effects of known or suspected factors that promote chondrogenic differentiation in growth plate and arteries.
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Affiliation(s)
- D Magne
- INSERM EM 99-03, Research Center on Osteoarticular and Dental Tissue Engineering, Nantes, France
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Varandas L, Julien M, Gomes A, Rodrigues P, Van Lerberghe W, Malveiro F, Aguiar P, Kolsteren P, Van Der Stuyft P, Hilderbrand K, Labadarios D, Ferrinho P. A randomised, double-blind, placebo-controlled clinical trial of vitamin A in severe malaria in hospitalised Mozambican children. Ann Trop Paediatr 2001; 21:211-22. [PMID: 11579859 DOI: 10.1080/02724930120077781] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
This paper reports a randomised, double-blind, placebo-controlled clinical trial of the effect of routine vitamin A supplementation given on admission to children with severe malaria with regard to survival, recovery during hospitalisation and outcome 6 weeks after discharge. Children aged between 6 and 72 months admitted to the paediatric wards of the Central Hospital of Maputo (CHM), Mozambique with a diagnosis of severe malaria were randomly assigned either to a control group (placebo) or an experimental group (vitamin A) and were followed up 6 weeks after discharge. There were 280 children in the experimental and 290 in the placebo group. Seven (2.5%) and 13 (4.5%) children died in the experimental and the placebo groups, respectively, a relative risk of death of 0.56 (95% CI 0.23-1.38, p = 0.201). During the 1st 5 hours of admission, the relative risk of death in the vitamin A-supplemented group was 2.54 (0.50-12.96); after 5 hours of admission it was 0.19 (95% CI 0.04-0.85; p = 0.015). In the supplemented group, 4/82 (4.9%) of the children developed neurological sequelae vs 2/78 (2.6%) in the placebo group (RR = 1.90; 95% CI 0.36-10.09; p = 0.682). Although the overall reduction in the risk of death observed for all children receiving vitamin A is not statistically significant, it might be clinically important. This finding cannot, however, be accepted as a firm conclusion and requires validation by future trials.
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Affiliation(s)
- L Varandas
- Health Systems Unit and Centre for Malaria and other Tropical Diseases, Institute of Hygiene and Tropical Medicine, New University of Lisbon, Portugal.
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Daoud R, Julien M, Gros P, Georges E. Major photoaffinity drug binding sites in multidrug resistance protein 1 (MRP1) are within transmembrane domains 10-11 and 16-17. J Biol Chem 2001; 276:12324-30. [PMID: 11152467 DOI: 10.1074/jbc.m009782200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
MRP1 is an ABC (or ATP binding cassette) membrane transport protein shown to confer resistance to structurally dissimilar drugs. Studies of MRP1 topology suggested the presence of a hydrophobic N-domain with five potential membrane-spanning domains linked to an MDR1-like core (MSD1-NBD1-L1-MSD2-NBD2) by an intracellular linker domain (L0). MRP1-mediated multidrug resistance is thought to be due to enhanced drug efflux. However, little is known about MRP1-drug interaction and its drug binding site(s). We previously developed several photoreactive probes to study MRP1-drug interactions. In this report, we have used eight MRP1-HA variants that were modified to have hemagglutinin A (HA) epitopes inserted at different sites in MRP1 sequence. Exhaustive in-gel digestion of all IAARh123 photoaffinity-labeled MRP1-HA variants revealed the same profile of photolabeled peptides as seen for wild type MRP1. Photolabeling of the different MRP1-HA variants followed by digestion with increasing concentrations of trypsin or Staphylococcus aureus V8 protease (1:800 to 1:5 w/w) and immunoprecipitation with anti-HA mAb identified two small photolabeled peptides ( approximately 6-7 kDa) from MRP1-HA(574) and MRP1-HA(1222). Based on the location of the HA epitopes in the latter variants together with molecular masses of the two peptides, the photolabeled amino acid residues were localized to MRP1 sequences encoding transmembranes 10 and 11 of MSD1 (Ser(542)-Arg(593)) and transmembranes 16 and 17 of MSD2 (Cys(1205)-Glu(1253)). Interestingly, the same sequences in MRP1 were also photolabeled with a structurally different photoreactive drug, IACI, confirming the significance of transmembranes 10, 11, 16 and 17 in MRP1 drug binding. Taken together, the results in this study provide the first delineation of the drug binding site(s) of MRP1. Furthermore, our findings suggest the presence of common drug binding site(s) for structurally dissimilar drugs.
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Affiliation(s)
- R Daoud
- Institute of Parasitology and Department of Biochemistry, McGill University, Quebec H9X 3V9, Canada
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36
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Varandas L, Julien M, Van Lerberghe W, Goncalves L, Ferrinho P. Independent indicators of outcome in severe paediatric malaria: maternal education, acidotic breathing and convulsions on admission. Ann Trop Paediatr 2000; 20:265-71. [PMID: 11219163 DOI: 10.1080/1465328002003852] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Severe malaria is an important cause of death in hospitalized children in Mozambique, but the risk factors for this remain unclear. The objectives of the study were to define simple clinical criteria to identify on admission the children most at risk of dying. We studied prospectively 559 children admitted with severe malaria to the Department of Paediatrics of the Central Hospital of Maputo, Mozambique between March 1995 and August 1996. The case fatality rate was 3.6%. In a multiple logistic regression model, mothers' education (RR = 9.6, 95% CI 1.2-76.0), acidotic breathing (RR = 4.3, 95% CI 1.3-13.8) and convulsions in the emergency room (RR = 8.1, 95% CI 2.6-25.1) were associated with outcome. Together they predicted 97% of outcomes but only 33.3% of deaths.
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Affiliation(s)
- L Varandas
- Centro de Malária e de Outras Doenças Tropicais and Health Systems Unit, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisboa, Portugal.
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Urbatsch IL, Julien M, Carrier I, Rousseau ME, Cayrol R, Gros P. Mutational analysis of conserved carboxylate residues in the nucleotide binding sites of P-glycoprotein. Biochemistry 2000; 39:14138-49. [PMID: 11087362 DOI: 10.1021/bi001128w] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mutagenesis was used to investigate the functional role of six pairs of aspartate and glutamate residues (D450/D1093, E482/E1125, E552/E1197, D558/D1203, D592/D1237, and E604/E1249) that are highly conserved in the nucleotide binding sites of P-glycoprotein (Mdr3) and of other ABC transporters. Removal of the charge in E552Q/E1197Q and D558N/D1203N produced proteins with severely impaired biological activity when the proteins were analyzed in yeast cells for cellular resistance to FK506 and restoration of mating in a ste6Delta mutant. Mutations at other acidic residues had no apparent effect in the same assays. These four mutants were expressed in Pichia pastoris, purified to homogeneity, and biochemically characterized with respect to ATPase activity. Studies with purified proteins showed that mutants D558N and D1203N retained 14 and 30% of the drug-stimulated ATPase activity of wild-type (WT) Mdr3, respectively, and vanadate trapping of 8-azido[alpha-(32)P]nucleotide confirmed slower basal and drug-stimulated 8-azido-ATP hydrolysis compared to that for WT Mdr3. The E552Q and E1197Q mutants showed no drug-stimulated ATPase activity. Surprisingly, drugs did stimulate vanadate trapping of 8-azido[alpha-(32)P]nucleotide in E552Q and E1197Q at a level similar to that of WT Mdr3. This suggests that formation of the catalytic transition state can occur in these mutants, and that the bond between the beta- and gamma-phosphates is hydrolyzed. In addition, photolabeling by 8-azido[alpha-(32)P]nucleotide in the presence or absence of drug was also detected in the absence of vanadate in these mutants. These results suggest that steps after the transition state, possibly involved in release of MgADP, are severely impaired in these mutant enzymes.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B/genetics
- ATP Binding Cassette Transporter, Subfamily B/metabolism
- ATP Binding Cassette Transporter, Subfamily B/physiology
- ATP Binding Cassette Transporter, Subfamily B, Member 1/biosynthesis
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- ATP Binding Cassette Transporter, Subfamily B, Member 1/isolation & purification
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- ATP-Binding Cassette Transporters/genetics
- ATP-Binding Cassette Transporters/metabolism
- ATP-Binding Cassette Transporters/physiology
- Adenosine Triphosphate/analogs & derivatives
- Adenosine Triphosphate/metabolism
- Amino Acid Sequence
- Amino Acid Substitution/genetics
- Animals
- Azides/metabolism
- Binding Sites/genetics
- Carboxylic Acids/metabolism
- Conserved Sequence
- DNA Mutational Analysis
- Drug Resistance, Multiple
- Genetic Vectors/metabolism
- Mice
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Oligonucleotides/metabolism
- Photoaffinity Labels/metabolism
- Pichia/genetics
- Pichia/metabolism
- Vanadates/metabolism
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Affiliation(s)
- I L Urbatsch
- Department of Biochemistry, McGill University, Montréal, Québec, Canada H3G 1Y6
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38
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Julien M, Gros P. Nucleotide-induced conformational changes in P-glycoprotein and in nucleotide binding site mutants monitored by trypsin sensitivity. Biochemistry 2000; 39:4559-68. [PMID: 10758006 DOI: 10.1021/bi992744z] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Limited trypsin digestion was used to monitor nucleotide-induced conformational changes in wild-type P-glycoprotein (Pgp) as well as in nucleotide binding domain (NBD) Pgp mutants. Purified and reconstituted wild-type or mutant mouse Mdr3 Pgps were preincubated with different hydrolyzable or nonhydrolyzable nucleotides, followed by limited proteolytic cleavage at different trypsin:protein ratios. The Pgp tryptic digestion products were separated by SDS-PAGE followed by immunodetection with the mouse monoclonal anti-Pgp antibody C219, which recognizes a conserved epitope (VVQE/AALD) in each half of the protein. Different trypsin digestion patterns were observed for wild-type Pgp incubated with MgCl(2) alone, MgADP, MgAMP.PNP, MgATP, and MgATP + vanadate. A unique trypsin digestion profile suggestive of enhanced resistance to trypsin was observed under conditions of vanadate-induced trapping of nucleotides (MgATP + vanadate). The trypsin sensitivity profiles of Pgp mutants bearing either single or double mutations in Walker A (K429R, K1072R) and Walker B (D551N, D1196N) sequence signatures of NBD1 and NBD2 were analyzed under conditions of vanadate-induced trapping of nucleotides. The proteolytic cleavage pattern observed for the double mutants K429R/K1072R and D551N/D1196N, and for the single mutants K429R, K1072R, and D1196N were similar and clearly distinct from wild-type Pgp under the same conditions. This is consistent with the absence of ATP hydrolysis and of vanadate-induced trapping of 8-azido-ADP previously reported for these mutants [Urbatsch et al. (1998) Biochemistry 37, 4592-4602]. Interestingly, the trypsin digestion profiles observed under vanadate-induced trapping for the D551N and D1196N mutants were quite different, with the D551N mutant showing a profile resembling that seen for wild-type Pgp. The different sensitivity profiles of Pgp mutants bearing mutations at the homologous residue in NBD1 (D551N) and NBD2 (D1196N) suggest possible structural and functional differences between the two sites.
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Affiliation(s)
- M Julien
- Department of Biochemistry, McGill University, Montréal, Québec, Canada, H3G 1Y6
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Julien M, Feher T, Horvatic M, Berthier C, Bakharev ON, Segransan P, Collin G, Marucco J. 63Cu NMR evidence for enhanced antiferromagnetic correlations around Zn impurities in YBa2Cu3O6.7. Phys Rev Lett 2000; 84:3422-3425. [PMID: 11019105 DOI: 10.1103/physrevlett.84.3422] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/1999] [Indexed: 05/23/2023]
Abstract
Doping the high- T(c) superconductor YBa2Cu3O6.7 with 1.5% of nonmagnetic Zn impurities in CuO2 planes is shown to produce a considerable broadening of 63Cu NMR spectra, as well as an increase of low-energy magnetic fluctuations detected in 63Cu spin-lattice relaxation measurements. A model-independent analysis demonstrates that these effects are due to the development of staggered magnetic moments on many Cu sites around each Zn and that the Zn-induced moment in the bulk susceptibility might be explained by this staggered magnetization. Several implications of these enhanced antiferromagnetic correlations are discussed.
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Affiliation(s)
- M Julien
- Grenoble High Magnetic Field Laboratory, CNRS and MPI-FKF,BP 166, F-38042 Grenoble Cedex 9, France and Laboratoire de Spectrometrie Physique, Universite J. Fourier, BP 87, F-38402 St. Martin d'Heres, France
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40
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Julien M. Nutrition: its role in dental training and practice. J Can Dent Assoc 2000; 66:97-9. [PMID: 10730009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Affiliation(s)
- M Julien
- Department of Oral Health, Faculty of Dental Medicine, University of Montreal, QC
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41
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Julien M, Kajiji S, Kaback RH, Gros P. Simple purification of highly active biotinylated P-glycoprotein: enantiomer-specific modulation of drug-stimulated ATPase activity. Biochemistry 2000; 39:75-85. [PMID: 10625481 DOI: 10.1021/bi991726e] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A simplified method for the expression and purification of P-glycoprotein (Pgp) is presented. This method is based on the in-frame fusion of both a polyhistidine tail and a 100-amino acid residue biotin acceptor domain of oxaloacetate decarboxylase from Klebsiella pneumoniae at the carboxyl terminus end of Pgp (Pgp-H6BD). The expression/purification protocol for Pgp-H6BD involves high-level expression of the fusion protein in the yeast Pichia pastoris, biotinylation in vitro with biotin ligase, solubilization of crude membrane fractions in detergent, and affinity purification by a combination of nickel and avidin chromatography. Biotinylated Pgp binds to immobilized monomeric avidin and can be eluted with free biotin in a high state of purity. This protocol is rapid and efficient and yields purified Pgp which shows robust ATPase activity, as determined by vanadate-induced trapping of photoactive nucleotides and by direct measurement of ATP hydrolysis by Pgp-H6BD. This method should be useful for structural studies of the protein by spectroscopic or crystallographic approaches. This purified Pgp-H6BD preparation has been used to study the enantiomer-specific effects of inhibitors of Pgp-mediated drug transport on the drug-stimulated ATPase activity of the protein. A series of 1, 4-disubstituted piperazine derivatives with a central chiral carbon and modified at the head and tail groups are shown to stimulate Pgp ATPase activity in a dose-dependent fashion. Some of these compounds are also capable of inhibiting either vinblastine or verapamil stimulation of ATPase activity of Pgp in an enantiomer-specific fashion. The enantiomeric specific inhibitory activity of these compounds suggests complex interactions at a single substrate binding site(s) on Pgp.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B/biosynthesis
- ATP Binding Cassette Transporter, Subfamily B/genetics
- ATP Binding Cassette Transporter, Subfamily B/metabolism
- ATP Binding Cassette Transporter, Subfamily B, Member 1/antagonists & inhibitors
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- ATP Binding Cassette Transporter, Subfamily B, Member 1/isolation & purification
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- ATP-Binding Cassette Transporters/biosynthesis
- ATP-Binding Cassette Transporters/genetics
- ATP-Binding Cassette Transporters/metabolism
- Adenosine Triphosphatases/antagonists & inhibitors
- Adenosine Triphosphatases/genetics
- Adenosine Triphosphatases/isolation & purification
- Adenosine Triphosphatases/metabolism
- Animals
- Biotinylation
- Drug Resistance, Multiple
- Enzyme Activators/pharmacology
- Histidine
- Humans
- Klebsiella pneumoniae/genetics
- Mice
- Peptides/genetics
- Pichia/genetics
- Piperazines/pharmacology
- Quinolines/pharmacology
- Recombinant Fusion Proteins/biosynthesis
- Recombinant Fusion Proteins/isolation & purification
- Recombinant Fusion Proteins/metabolism
- Stereoisomerism
- Thiazoles/pharmacology
- Tumor Cells, Cultured
- Verapamil/pharmacology
- Vinblastine/pharmacology
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Affiliation(s)
- M Julien
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
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Abstract
The murine monoclonal antibody 2A7 was found to react specifically with a 85-kDa human protein which is distributed throughout the nuclear interior in interphase and becomes associated with condensed chromosomes during mitosis. The 2A7 epitope was not detected in cells from other species. Two-dimensional immunoblotting analysis of HeLa cell homogenates further indicated that the 85-kDa polypeptide species recognized by the 2A7 antibody corresponds to an acidic protein which may be complexed in vivo within high-molecular-weight protein structures. Immunofluorescence monitoring of the 2A7 staining pattern during in situ preparation of nuclear matrices from HeLa cells demonstrated that the nucleoplasmic fraction of the antigen is readily solubilized by detergent and salts, whereas the nucleolar fraction resists detergent/salt extraction and DNase digestion, to be released only upon RNase activity. Mobility assays in human-mouse heterokaryons provided evidence that the 2A7 antigen is a nucleocytoplasmic shuttling protein. The nuclear distribution of this antigen remained unchanged upon drug-induced inhibition of RNA synthesis but was markedly altered by heat shock stress. All together, the data presented here suggest that the 2A7 antigen may have a function in RNA metabolism.
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Affiliation(s)
- M Paulin-Levasseur
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada.
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43
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Julien M, Verrier B, Cerutti M, Chappe V, Gola M, Devauchelle G, Becq F. Cystic fibrosis transmembrane conductance regulator (CFTR) confers glibenclamide sensitivity to outwardly rectifying chloride channel (ORCC) in Hi-5 insect cells. J Membr Biol 1999; 168:229-39. [PMID: 10191357 DOI: 10.1007/s002329900512] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Increasing evidence is now accumulating for the involvement of the cystic fibrosis transmembrane conductance regulator (CFTR) in the control of the outwardly rectifying chloride channel (ORCC). We have examined the sensitivity of ORCC to the sulfonylurea drug glibenclamide in Hi-5 (Trichoplusia ni) insect cells infected with recombinant baculovirus expressing either wild-type CFTR, DeltaF508-CFTR or E. coli beta galactosidase cDNA and in control cells either infected with virus alone or uninfected. Iodide efflux and single channel patch-clamp experiments confirmed that forskolin and 1-methyl-3-isobutyl xanthine (IBMX) or 7-methyl-1,3 dipropyl xanthine (DPMX) activate CFTR channels (unitary conductance: 9.1 +/- 1.6 pS) only in cells expressing CFTR. In contrast, we identified 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid (SITS)-sensitive ORCC in excised membrane patches in any of the cells studied, with similar conductance (22 +/- 2.5 pS at -80 mV; 55 +/- 4.1 pS at +80 mV) and properties. In the presence of 500 microm SITS, channel open probability (Po) of ORCC was reversibly reduced to 0.05 +/- 0.01 in CFTR-cells, to 0.07 +/- 0.02 in non-CFTR expressing cells and to 0.05 +/- 0.02 in DeltaF508-cells. In Hi-5 cells that did not express CFTR, glibenclamide failed to inhibit ORCC activity even at high concentrations (100 microm), whereas 500 microm SITS reversibly inhibited ORCC. In contrast in cells expressing CFTR or DeltaF508, glibenclamide dose dependently (IC50 = 17 microm, Hill coefficient 1.2) and reversibly inhibited ORCC. Cytoplasmic application of 100 microm glibenclamide reversibly reduced Po from 0.88 +/- 0.03 to 0.09 +/- 0.02 (wash: Po = 0.85 +/- 0.1) in CFTR cells and from 0.89 +/- 0.05 to 0.08 +/- 0.05 (wash: Po = 0.87 +/- 0.1) in DeltaF508 cells. In non-CFTR expressing cells, glibenclamide (100 microm) was without effect on Po (control: Po = 0. 89 +/- 0.09, glib.: Po = 0.86 +/- 0.02; wash: Po = 0.87 +/- 0.05). These data strongly suggest that the expression of CFTR confers glibenclamide sensitivity to the ORCC in Hi-5 cells.
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Affiliation(s)
- M Julien
- Station de Recherche de Pathologie Comparée INRA-CNRS 30180 Saint-Christol-lez-Alès F-30380, France
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Guérin N, Urtasun A, Chauveau E, Julien M, Lebreton M, Dumon M. [Lingual thyroid and intra-lingual thyroglossal cyst. Apropos of 2 cases]. Rev Laryngol Otol Rhinol (Bord) 1998; 118:183-8. [PMID: 9637108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Lingual thyroid and intra lingual thyro-glossal cyst are two benign tumours of similar embryological pathogenesis respectively with the arrest in the ectopic position of the thyroid gland during its downward migration and from abnormal persistence of the thyro-glossal tract for the cyst. The occurrence of lingual thyroid is rare 1/100,000 patients and outnumbers the incidence of intra-lingual cyst which represents an estimated 2.1% of the thyro-glossal cysts or fistulas. Both lesions are a rare cause of dysphagia and dyspnoea due to oropharyngeal obstruction, and radionuclide scintigraphy combined with CT and/or MRI will establish the diagnosis. Surgical pharyngotomy with an infra-hyoid approach provides excellent access to the lesions and complete removal of the tumours.
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Affiliation(s)
- N Guérin
- C.H.G. R. Boulin, Clinique O.R.L., Libourne, France
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Julien M, Millot C, Tocanne JF, Tournier JF. 12-O-tetradecanoylphorbol-13-acetate inhibits aminophospholipid translocase activity and modifies the lateral motions of fluorescent phospholipid analogs in the plasma membrane of bovine aortic endothelial cells. Exp Cell Res 1997; 234:125-31. [PMID: 9223377 DOI: 10.1006/excr.1997.3592] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) is a potent mitogenic factor which can replace the growth promoting activity of basic fibroblast growth factor (bFGF) on bovine aortic endothelial cells. However, TPA-treated cells lose their strict contact inhibition at confluence, which is a characteristic of cells grown in the presence of bFGF. We have examined whether these changes could be related to modifications of the transbilayer and lateral motions of fluorescent lipids, namely 1-acyl-2-[6-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]caproyl]-p hosphatidylcholine (C6-NBD-PC), -phosphatidylserine (C6-NBD-PS), and -phosphatidylethanolamine (C6-NBD-PE) inserted in the outer leaflet of the cell plasma membrane. In TPA-treated cells, the three fluorescent phospholipids remained located in the outer leaflet for at least 1 h at 20 degrees C after their insertion, indicating a blockade of the aminophospholipid translocase activity which is normally present in the plasma membrane of bFGF-treated cells. TPA also induced a large increase in the percentage of C6-NBD-PC and C6-NBD-PE probes which were free to diffuse laterally. The mobile fractions M reached values of approximately 100% for the two lipids, while for bFGF-treated cells they were found around 85 and 75%, respectively. For the C6-NBD-PS probe, M remained unchanged in bFGF and TPA-treated cells, at around 85%. TPA treatment also induced a twofold increase in the lateral diffusion coefficients of C6-NBD-PC and C6-NBD-PE, while that of C6-NBD-PS remained nearly unchanged. These effects of TPA may be related to the observed loss of differentiated properties of vascular endothelial cells and not to its mitogenic properties.
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Affiliation(s)
- M Julien
- Institut de Pharmacologie et de Biologie Structurale du CNRS, 118, Toulouse, France
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46
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Julien M, Létouneau DR, Marois Y, Cardou A, King MW, Guidoin R, Chachra D, Lee JM. Shelf-life of bioprosthetic heart valves: a structural and mechanical study. Biomaterials 1997; 18:605-12. [PMID: 9134160 DOI: 10.1016/s0142-9612(96)00155-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This study was undertaken to evaluate the influence of storage conditions on the shelf-life of porcine bioprosthetic valves. Fifty-five unimplanted porcine bioprostheses have been evaluated. The valves were stored in 0.5% buffered glutaraldehyde solution for different periods of time (7, 23 and 32 months). Twenty-eight valves were refrigerated while the remaining valves were stored at room temperature. The pH of the glutaraldehyde solution at room temperature decreased with time of storage, while that kept in the refrigerator remained stable over the course of the study. Macroscopic observations showed that the valve tissues kept at room temperature, especially for the periods of 23 and 32 months, became darker and more yellow in colour, whereas the refrigerated specimens exhibited no such changes in appearance. Scanning electron microscopy analysis revealed no noticeable differences on the surfaces of the leaflets stored under different conditions. Mechanical tests, including stress-strain response, stress relaxation and fracture behaviour, were carried out. Analysis of variance showed that the storage temperature, but not the length of storage, had a significant effect on some mechanical properties. The stress relaxation at 1000 s (P = 0.05), the ultimate tensile strength (P = 0.01) and the strain at fracture (P = 0.04) were all higher after storage at room temperature compared to the results after refrigeration. No statistically significant changes in the denaturation temperature of the collagen were observed between the different storage conditions. In conclusion, the storage temperature appears to have some influence on the bioprosthetic tissue. The bioprostheses stored under ambient conditions experience changes which may influence their longterm in vivo performance.
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Affiliation(s)
- M Julien
- Institut des biomatériaux du Québec Inc., CHUQ, Canada
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Veyrières M, Baillet P, Hay JM, Fingerhut A, Bouillot JL, Julien M. Factors influencing long-term survival in 100 cases of small intestine primary adenocarcinoma. Am J Surg 1997; 173:237-9. [PMID: 9124635 DOI: 10.1016/s0002-9610(97)89599-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Factors influencing long-term survival in patients undergoing operation for adenocarcinoma of the small intestine are poorly recognized. METHODS Retrospective study of 100 cases culled within a 10-year period by questionnaire, including 59 males and 41 females, median age 61 years (range 30 to 86). No patients were lost to follow-up (median 27 months). All patients underwent operation: curative in 65% and palliative in 35%. RESULTS Overall actuarial 5-year survival was 38%, 0% after palliative treatment and 54% after curative resection. In patients undergoing curative resection, 5-year survival was 63% when the lymph nodes were not involved, and 52% when they were; 57% when the serosa was not involved, and 53% when it was; 56% when the tumor was well or moderately well differentiated and 40% when it was undifferentiated. Other factors influencing long-term survival were the emergency setting, the site, the multiplicity, and the size of tumor (none with statistically significant differences). Five and 10-year survival was 78% and 69%, respectively, when the patient was anemic compared with 35% and 17%, respectively when the patient was not (P <0.01). There were 14 patients with previous carcinoma, 2 with Crohn's disease, and 1 each with celiac disease and ileal tuberculosis. There were also 8 patients with associated duodenal and proximal jejunal polyps. Thirteen patients sustained a total of 14 further cancers. CONCLUSIONS Patients should be followed up closely because the possibility of sustaining another abdominal carcinoma is high (16%). As associated polyps are nearly always duodenal or jejunal, preoperative or intraoperative endoscopy of the upper gastrointestinal tract including the initial portion of the jejunum should be able to detect their presence and reduce the risk of early recurrence.
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Affiliation(s)
- M Veyrières
- French Associations for Surgical Research, Bois-Colombes
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Yang M, Deng X, Zhang Z, Julien M, Pelletier F, Desaulniers D, Cossette R, Teijeira FJ, Laroche G, Guidoin R. Are intraaortic balloons suitable for reuse? A survey study of 112 used intraaortic balloons. Artif Organs 1997; 21:121-30. [PMID: 9028494 DOI: 10.1111/j.1525-1594.1997.tb00348.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
To assess the safety of reusing single-use intraaortic balloon devices (IABs), 112 used devices were investigated in terms of physical integrity, gas leakage inspection, mechanical performance, surface chemistry and morphology, and physical stability. These IABs were all used clinically only once, and the duration of the IABs in vivo ranged from 6 to 312 h. Macroscopic examination of the balloons and the outer catheters revealed no obvious change in either shape or color. No discernible abrasions or cracks were observed on the balloons. However, 61% of the balloons were creased, and 40% of the central lumens and 21% of the sheaths showed visible bending flaws. Moreover, 65% of the balloons and 38% of the central lumens were contaminated by visible residual organic debris. The physical integrity of each device was verified in a specially designed leakage-fatigue tester for 72 h. Ninety-seven percent of the devices passed the leakage inspection. Stress-strain testing, differential scanning calorimetry, attenuated total reflection-Fourier transform infrared, and scanning electron microscopy analyses clearly indicated that there were no significant differences in the mechanical properties, bulk material morphology, surface chemistry, and external surface morphology between the used balloons and virgin controls. Although some surface modifications occurred on the internal side of the balloons, the external surfaces of most balloons suffered no trauma. Most of the used IABs examined in this study maintained physical and mechanical properties similar to those of the virgin devices. The chemistry of the balloon material was stable after short-term in vivo use. However, it does not seem possible to establish a rigorous protocol of cleaning, sterilization, and inspection to guarantee a safer reuse of these devices. The presence of residual organic debris that cannot be eliminated results in an imperative preclusion not to reuse the IABs.
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Affiliation(s)
- M Yang
- Department of Surgery, Laval University, Quebec, Canada
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Prévost C, Julien M, Brown BP. Suicides associated with the Jacques Cartier Bridge, Montreal, Quebec 1988-1993: descriptive analysis and intervention proposal. Can J Public Health 1996; 87:377-80. [PMID: 9009392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Falls from heights represent an uncommon means of suicide. Regional variations are attributable to the presence of particular sites which attract suicidal individuals. The Jacques Cartier Bridge in Montreal is one such site, though less well known than North American sites such as the Golden Gate Bridge or Niagara Falls. According to Coroner's records, 54 suicides were associated with the bridge for the period 1988 to 1993. All but one of the suicides were the result of jumps from the bridge. The median age of victims was 30 years, and 46 of the victims were male. Bridge-specific verbalization of suicidal intent and prior history of medically diagnosed psychiatric disorders are frequently noted. Based on a review of the effectiveness of preventive measures, we propose limiting access to jumping by means of a fence along the bridge railing.
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Affiliation(s)
- C Prévost
- Department of Public Health, Régie Régionale de la Santé et des Services Sociaux de la Montérégie, St-Hubert (Québec)
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Julien M, Carretta P, Horvatic M, Berthier C, Berthier Y, Ségransan P, Carrington A, Colson D. Spin gap in HgBa2Ca2Cu3O8+ delta single crystals from 63Cu NMR. Phys Rev Lett 1996; 76:4238-4241. [PMID: 10061236 DOI: 10.1103/physrevlett.76.4238] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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