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1. Nitric Oxide Is Involved in the Response of the Isolated Intact and Epithelium-Denuded Rat Trachea to the β2 Adrenergic Receptor Agonist Salbutamol

Author

J. Carmona, G. Santacana, G. Santos, I. Torres, D. Dexter, F. Montalvo, M. Vega, and O. Cantres-Fonseca

Subjects
Pulmonary and Respiratory Medicine, Agonist, medicine.medical_specialty, Tracheal Epithelium, Carbachol, medicine.drug_class, business.industry, Endogeny, respiratory system, Epithelium, In vitro, Nitric oxide, chemistry.chemical_compound, medicine.anatomical_structure, Endocrinology, chemistry, Internal medicine, parasitic diseases, medicine, Salbutamol, business, medicine.drug
Abstract

Background: The involvement of the airway smooth muscle mediator nitric oxide (NO) in the actions of the β2 agonist salbutamol (Sal), a well- known bronchodilator, is very poorly understood. Objectives: To determine if endogenous NO release is a major factor in the Sal-induced relaxation of the carbachol- and electrical field-stimulated rat trachea and determine the role of the tracheal epithelium as the possible source of NO involved in these effects. Methods: Isolated carbachol- or electric field-stimulated pre-contracted in vitro male Sprague Dawley rat tracheas (with epithelium intact or denuded) were relaxed with incremental or discrete concentrations of Sal in the presence and absence of the NO synthesis inhibitor L-NAME. Results: Epithelium-denuded tracheas showed a reduced relaxation response to Sal. L-NAME (1 mM) similarly decreased the sensitivity of the rat tracheas to Sal in both epithelium-intact and -denuded conditions. In the presence of L-NAME, high concentrations of Sal induced an unexpectedly large relaxation response in carbachol-stimulated rat tracheas with both intact and denuded epithelium. Sal relaxation was also affected by L-NAME in electrical field-stimulated epithelium-intact and -denuded tracheas. Conclusion: The results suggest that NO derived from sources other than the epithelium is an important mediator of the Sal-induced relaxation in rat tracheas.

Published
2010
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2. Physical models of ten asteroids from an observers' collaboration network

Author

R. Dymock, F. Manzini, S. Boroumand, Stephen M. Slivan, Robert D. Stephens, R. A. Koff, Greg Bolt, M. Fagas, R. Roy, Michael Fauerbach, Brian D. Warner, Josef Ďurech, Margaret Pan, A. Marciniak, M. Crow, Angel F. Lopez, Mikko Kaasalainen, Merideth Frey, Frederick Pilcher, Rita Pacheco, Thomas Bennett, S. Fauvaud, L. Crespo da Silva, C. Bembrick, W. Pych, Donald P. Pray, R. Crippa, Raoul Behrend, R. Poncy, S. Sposetti, Jérôme Berthier, T. Kwiatkowski, Marek Wolf, G. Santacana, R. Durkee, D. Jardine, Krzysztof Kamiński, Tadeusz Michalowski, W. H. Allen, Rui Soles Gonçalves, L. Bernasconi, R. Hirsch, Astronomical Institute, Charles University, Department of Mathematics and Statistics, Rolf Nevanlinna Institute, University of Helsinki, Astronomical Observatory, Adam Mickiewicz University, Vintage Lane Observatory, Observatoire Astronomique de l'Université de Genève, Mount Tarana Observatory, Florida Gulf Coast University, Observatoire des Engarouines, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Groupe Astrométrie et Planétologie (GAP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Stazzione Astronomica di Sozzago, The WW Crow Observatory, Shed of Science Observatory, Association AstroQueyras, Groupe européen d’observation stellaire (GEOS), Department of Astronomy, Whitin Observatory, Wellesley College, Observatório Astronómico de Linhaceira, Illinois College, Antelope Hills Observatory, 980 Antelope Drive West, Bennett, Observatori Astronomic de Consell, Carbuncle Hill Observatory, Centrum Astronomiczne im. M. Kopernika, Warszawa (CAMK), Observatoire de Blauvac, Observatorio di Gnosca, Goat Mountain Astronomical Research Station, and Palmer Divide Observatory, Colorado Springs

Subjects
Physics, Physical model, 010504 meteorology & atmospheric sciences, Astronomy, Astronomy and Astrophysics, Inversion (meteorology), Astrophysics, 01 natural sciences, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Asteroid, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract

International audience; Aims:We present physical models of ten asteroids obtained by means of lightcurve inversion. A substantial part of the photometric data was observed by amateur astronomers. We emphasize the importance of a coordinated network of observers that will be of extreme importance for future all-sky asteroid photometric surveys. Methods: The lightcurve inversion method was used to derive spin states and shape models of the asteroids. Results: We derived spin states and shape model for ten new asteroids: (110) Lydia, (125) Liberatrix, (130) Elektra, (165) Loreley, (196) Philomela, (218) Bianca, (306) Unitas, (423) Diotima, (776) Berbericia, and (944) Hidalgo. This increases the number of asteroid models up to nearly one hundred.

Published
2007
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3. Asteroids' physical models from combined dense and sparse photometry and scaling of the YORP effect by the observed obliquity distribution

Author

J. Hanuš, J. Ďurech, M. Brož, A. Marciniak, B. D. Warner, F. Pilcher, R. Stephens, R. Behrend, B. Carry, D. Čapek, P. Antonini, M. Audejean, K. Augustesen, E. Barbotin, P. Baudouin, A. Bayol, L. Bernasconi, W. Borczyk, J.-G. Bosch, E. Brochard, L. Brunetto, S. Casulli, A. Cazenave, S. Charbonnel, B. Christophe, F. Colas, J. Coloma, M. Conjat, W. Cooney, H. Correira, V. Cotrez, A. Coupier, R. Crippa, M. Cristofanelli, Ch. Dalmas, C. Danavaro, C. Demeautis, T. Droege, R. Durkee, N. Esseiva, M. Esteban, M. Fagas, G. Farroni, M. Fauvaud, S. Fauvaud, F. Del Freo, L. Garcia, S. Geier, C. Godon, K. Grangeon, H. Hamanowa, N. Heck, S. Hellmich, D. Higgins, R. Hirsch, M. Husarik, T. Itkonen, O. Jade, K. Kamiński, P. Kankiewicz, A. Klotz, R. A. Koff, A. Kryszczyńska, T. Kwiatkowski, A. Laffont, A. Leroy, J. Lecacheux, Y. Leonie, C. Leyrat, F. Manzini, A. Martin, G. Masi, D. Matter, J. Michałowski, M. J. Michałowski, T. Michałowski, J. Michelet, R. Michelsen, E. Morelle, S. Mottola, R. Naves, J. Nomen, J. Oey, W. Ogłoza, A. Oksanen, D. Oszkiewicz, P. Pääkkönen, M. Paiella, H. Pallares, J. Paulo, M. Pavic, B. Payet, M. Polińska, D. Polishook, R. Poncy, Y. Revaz, C. Rinner, M. Rocca, A. Roche, D. Romeuf, R. Roy, H. Saguin, P. A. Salom, S. Sanchez, G. Santacana, T. Santana-Ros, J.-P. Sareyan, K. Sobkowiak, S. Sposetti, D. Starkey, R. Stoss, J. Strajnic, J.-P. Teng, B. Trégon, A. Vagnozzi, F. P. Velichko, N. Waelchli, K. Wagrez, H. Wücher, Astronomical Institute of Charles University, Charles University [Prague] (CU), Astronomical Observatory [Poznan], Adam Mickiewicz University in Poznań (UAM), Palmer Divide Observatory, Organ Mesa Observatory, Goat Mountain Astronomical Research Station, Geneva Observatory, Université de Genève = University of Geneva (UNIGE), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA), Astronomical Institute of the Czech Academy of Sciences (ASU / CAS), Czech Academy of Sciences [Prague] (CAS), Observatoire de Bédoin, Observatoire de Chinon, Courbes de rotation d'astéroïdes, de comètes et d'étoiles variables (CdR & CdL group), CdR & CdL group, Association T60, Observatoire Midi-Pyrénées, Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Harfleur Observatory, Observatoire des Engarouines, Collonges Observatory, Chercheur indépendant, Observatoire N°139 d'Antibes, Osservatorio Colleverde di Guidonia, Observatoire de Saint-Sulpice N°947, DPHY, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Observatorio de San Gervasi, Observatoire de Cabris, Blackberry Observatory, Centre d'Astronomie de Saint-Michel l'Observatoire, Observatoire de Sainte-Hélène, Observatorio Astronómico de Tradate, 138 Village-Neuf, The Amateur Sky Survey (TASS), The Amateur Sky Survey, Shed of Science Observatory, Association AstroQueyras, Association des Utilisateurs de Détecteurs Electroniques (AUDE), Association des Utilisateurs de Détecteurs Electroniques, Observatoire du Bois de Bardon, Dark Cosmology Centre (DARK), Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), Nordic Optical Telescope (NOT), Instituto de Astrofisica de Canarias (IAC), Hamanowa Astronomical Observatory, DLR Institute of Planetary Research, German Aerospace Center (DLR), Hunters Hill Observatory, Skalnaté Pleso Observatory, A83 Jakokoski Observatory, Institute of Physics [Kielce], Jan Kochanowski University, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Antelope Hills Observatory, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Stazione Astronomica di Sozzago, Forte Software, Scottish Universities Physics Alliance, Institute for Astronomy (SUPA), University of Edinburgh, Club d'Astronomie Lyon Ampéré [Vaulx-en-Velin] (CALA), Nyrölä Observatory (NYTT), Observatorio Montcabre, Observatorio Astronómico de Mallorca (OAM), Observatorio Astronómico de Mallorca, Kingsgrove Observatory, Mt. Suhora Observatory, Pedagogical University, Astronomy Department, Department of Physics [Helsinki], Falculty of Science [Helsinki], Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), François-Xavier Bagnoud Observatory, Blauvac Obsevatory, Blauvac Observatory, Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Gnosca Observatory, DeKalb Observatory, Observatoire astronomique des Makes, Laboratoire Kastler Brossel (LKB (Lhomond)), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Institute of Astronomy [Kharkiv], V.N. Karazin Kharkiv National University (KhNU), University of Geneva [Switzerland], European Space Agency (ESA), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), University of Helsinki-University of Helsinki, Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, photometry, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], media_common.quotation_subject, Population, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Inverse transform sampling, Astrophysics, 01 natural sciences, Photometry (optics), models, Observatory, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, education, 010303 astronomy & astrophysics, Scaling, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, media_common, Earth and Planetary Astrophysics (astro-ph.EP), Physics, education.field_of_study, Physical model, Minor planets, Astronomy and Astrophysics, Asteroids: general, 13. Climate action, Space and Planetary Science, Sky, Asteroid, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

The larger number of models of asteroid shapes and their rotational states derived by the lightcurve inversion give us better insight into both the nature of individual objects and the whole asteroid population. With a larger statistical sample we can study the physical properties of asteroid populations, such as main-belt asteroids or individual asteroid families, in more detail. Shape models can also be used in combination with other types of observational data (IR, adaptive optics images, stellar occultations), e.g., to determine sizes and thermal properties. We use all available photometric data of asteroids to derive their physical models by the lightcurve inversion method and compare the observed pole latitude distributions of all asteroids with known convex shape models with the simulated pole latitude distributions. We used classical dense photometric lightcurves from several sources and sparse-in-time photometry from the U.S. Naval Observatory in Flagstaff, Catalina Sky Survey, and La Palma surveys (IAU codes 689, 703, 950) in the lightcurve inversion method to determine asteroid convex models and their rotational states. We also extended a simple dynamical model for the spin evolution of asteroids used in our previous paper. We present 119 new asteroid models derived from combined dense and sparse-in-time photometry. We discuss the reliability of asteroid shape models derived only from Catalina Sky Survey data (IAU code 703) and present 20 such models. By using different values for a scaling parameter cYORP (corresponds to the magnitude of the YORP momentum) in the dynamical model for the spin evolution and by comparing synthetics and observed pole-latitude distributions, we were able to constrain the typical values of the cYORP parameter as between 0.05 and 0.6., Accepted for publication in A&A, January 15, 2013

Published
2013
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4. Photometry and models of selected main belt asteroids IX. Introducing interactive service for asteroid models (ISAM)

Author

Jari J. E. Kajava, K. Sobkowiak, F. Manzini, G. Santacana, C. Bembrick, A. Marciniak, R. Hirsch, Raoul Behrend, R. Poncy, Tayyaba Zafar, Desiree Della Monica Ferreira, Magdalena Polińska, Krzysztof Kamiński, S. Starczewski, Florent Colas, R. P. Hein Bertelsen, L. Bernasconi, S. Fauvaud, David Higgins, N. Esseiva, Michał J. Michałowski, R. Crippa, P. Antonini, T. Kwiatkowski, M. Fauvaud, F. P. Velichko, M. Fagas, A. Paschke, R. Roy, M. Stasik, J. M. Coloma, Tadeusz Michalowski, J. Michałowski, Agnieszka Kryszczyńska, Przemyslaw Bartczak, W. Borczyk, H. Wücher, Toni Santana-Ros, Astronomical Observatory [Poznan], Adam Mickiewicz University in Poznań (UAM), Observatoire de Bédoin, Geneva Observatory, University of Geneva [Switzerland], Observatoire des Engarouines, Service Interfaces et Capteurs (IFREMER), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Observatorio de San Gervasi, Observatorio Astronómico de Tradate, Association AstroQueyras, Association T60, Observatoire Midi-Pyrénées, Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Observatoire du Bois de Bardon, Hunters Hill Observatory, Stazione Astronomica di Sozzago, Groupe européen d’observation stellaire (GEOS), Chercheur indépendant, Laboratoire de Physique Nucléaire, Université Laval [Québec] (ULaval), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Université de Genève = University of Geneva (UNIGE), Service Interfaces et capteurs (IC), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Kapteyn Astronomical Institute, and Astronomy

Subjects
010504 meteorology & atmospheric sciences, Inverse transform sampling, Astrophysics, LIGHTCURVE INVERSION, minor planets, asteroids: general, 01 natural sciences, law.invention, Photometry, Photometry (optics), techniques: photometric, law, Radar imaging, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Radar, OPTIMIZATION METHODS, SHAPE DETERMINATION, Adaptive optics, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], PHOTOELECTRIC PHOTOMETRY, Astronomy, Astronomy and Astrophysics, Inversion (meteorology), Stars, Asteroids, asteroids: general, Space and Planetary Science, Asteroid, POLE, minor planets, ROTATION, Astrophysics::Earth and Planetary Astrophysics
Abstract

Context. The shapes and spin states of asteroids observed with photometric techniques can be reconstructed using the lightcurve inversion method. The resultant models can then be confirmed or exploited further by other techniques, such as adaptive optics, radar, thermal infrared, stellar occultations, or space probe imaging.Aims. During our ongoing work to increase the set of asteroids with known spin and shape parameters, there appeared a need for displaying the model plane-of-sky orientations for specific epochs to compare models from different techniques. It would also be instructive to be able to track how the complex lightcurves are produced by various asteroid shapes.Methods. Basing our analysis on an extensive photometric observational dataset, we obtained eight asteroid models with the convex lightcurve inversion method. To enable comparison of the photometric models with those from other observing/modelling techniques, we created an on-line service where we allow the inversion models to be orientated interactively.Results. Our sample of objects is quite representative, containing both relatively fast and slow rotators with highly and lowly inclined spin axes. With this work, we increase the sample of asteroid spin and shape models based on disk-integrated photometry to over 200. Three of the shape models obtained here are confirmed by the stellar occultation data; this also allowed independent determinations of their sizes to be made.Conclusions. The ISAM service can be widely exploited for past and future asteroid observations with various, complementary techniques and for asteroid dimension determination.

Published
2012
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5. The field high-amplitude SX Phe variable BL Cam: Results from a multisite photometric campaign: II. Evidence of a binary - Possibly triple - System

Author

M. Helvaci, M. Blauzek, V. Casanova, J. Michelet, G. Santacana, J. P. Sareyan, L. Kotková, A.-Y. Zhou, Hana Kučáková, S. Fauvaud, I. Scheggia, A. Avdibegovic, J. J. Rives, Petr Zasche, A. Nava-Vega, F. Fumagalli, M. Alvarez, C. Ulusoy, K. Truparová, J. Kliner, P. van Cauteren, B. Yasarsoy, Eric G. Hintz, Raoul Behrend, B. H. Granslo, L. Král, Cahit Yeşilyaprak, J. A. Farrell, S. Bartošíková, M. J. López-González, Patricia Lampens, M. Vilášek, Marek Wolf, F. Van Den Abbeel, G. Klingenberg, K. A. Graham, R. Kocián, I. Ribas, H. Wücher, Raul Michel, M. Fauvaud, John H. Simonetti, F. J. Aceituno, M. P. Nicholson, E. Rodriguez, J.-M. Vugnon, O. Trondal, L. Fox-Machado, Ege Üniversitesi, Observatoire du Bois de Bardon, Groupe européen d’observation stellaire (GEOS), Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut de Ciencies de l'Espai (ICE), Instituto de Astrofisica de Andalucia, CSIC (IAA), Koninklijke Sterrenwacht van België, Variable Star Section, Norwegian Astronomical Society, Sulphur Flats Observatory, Martin Observatory, Physics Dep., Virginia Polytechnic Institute & State University, Blacksburg, Astronomical Institute, Charles University, National Astronomical Observatoires-CAS, Observatorio Astronómico Nacional, Instituto de Astronomía, Universidad Nacional Autónoma de México, Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Societá Astronomica Le pleiadi, Observatoire des Trois Korrigans, Department of Physics and Astronomy, Brigham Young University, Beersel Hills Observatory, Department of Physics, Akdeniz University, Department of Physics, Ataturk University, American Association of Variable Star Observers (AAVSO), Project Eridanus, Observatory and Planetarium of Johann Palisa, Club d'Astronomie Lyon Ampéré [Vaulx-en-Velin] (CALA), Club Eclipse : Club d'Etudes du Ciel, de la Lune, des Instruments, des Planètes, du Soleil et des Etoiles..., Astronomical Institute, Academy of Sciences, Ege University Observatory, Vesqueville Observatory, and Observatoire Astronomique de l'Université de Genève

Subjects
Physics, Stars: individual: BL Camelopardalis, Stars: variables: ? Scuti, education.field_of_study, Cepheid variable, Population, Brown dwarf, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Stars, Orbit, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Stars: oscillations, Binaries: general, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Maxima, Instability strip, education, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Stellar evolution, Solar and Stellar Astrophysics (astro-ph.SR), Techniques: photometric
Abstract

Short-period high-amplitude pulsating stars of Population I ($\delta$ Sct stars) and II (SX Phe variables) exist in the lower part of the classical (Cepheid) instability strip. Most of them have very simple pulsational behaviours, only one or two radial modes being excited. Nevertheless, BL Cam is a unique object among them, being an extreme metal-deficient field high-amplitude SX Phe variable with a large number of frequencies. Based on a frequency analysis, a pulsational interpretation was previously given. aims heading (mandatory) We attempt to interpret the long-term behaviour of the residuals that were not taken into account in the previous Observed-Calculated (O-C) short-term analyses. methods heading (mandatory) An investigation of the O-C times has been carried out, using a data set based on the previous published times of light maxima, largely enriched by those obtained during an intensive multisite photometric campaign of BL Cam lasting several months. results heading (mandatory) In addition to a positive (161 $\pm$ 3) x 10$^{-9}$ yr$^{-1}$ secular relative increase in the main pulsation period of BL Cam, we detected in the O-C data short- (144.2 d) and long-term ($\sim$ 3400 d) variations, both incompatible with a scenario of stellar evolution. conclusions heading (mandatory) Interpreted as a light travel-time effect, the short-term O-C variation is indicative of a massive stellar component (0.46 to 1 M$_{\sun}$) with a short period orbit (144.2 d), within a distance of 0.7 AU from the primary. More observations are needed to confirm the long-term O-C variations: if they were also to be caused by a light travel-time effect, they could be interpreted in terms of a third component, in this case probably a brown dwarf star ($\geq$ 0.03 \ M$_{\sun}$), orbiting in $\sim$ 3400 d at a distance of 4.5 AU from the primary., Comment: 7 pages, 5 figures, accepted for publication in A&A

Published
2010
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6. Nitric oxide is involved in the response of the isolated intact and epithelium-denuded rat trachea to the β₂ adrenergic receptor agonist salbutamol

Author

F, Montalvo, O, Cantres-Fonseca, G, Santos, M, Vega, I, Torres, J, Carmona, D, Dexter, and G, Santacana

Subjects
Male, Muscle Relaxation, Muscle, Smooth, Cholinergic Agonists, Electric Stimulation, Epithelium, Rats, Rats, Sprague-Dawley, Trachea, NG-Nitroarginine Methyl Ester, Animals, Albuterol, Carbachol, Enzyme Inhibitors, Adrenergic beta-2 Receptor Agonists
Abstract

The involvement of the airway smooth muscle mediator nitric oxide (NO) in the actions of the β₂ agonist salbutamol (Sal), a well-known bronchodilator, is very poorly understood.To determine if endogenous NO release is a major factor in the Sal-induced relaxation of the carbachol- and electrical field-stimulated rat trachea and determine the role of the tracheal epithelium as the possible source of NO involved in these effects.Isolated carbachol- or electric field-stimulated pre-contracted in vitro male Sprague Dawley rat tracheas (with epithelium intact or denuded) were relaxed with incremental or discrete concentrations of Sal in the presence and absence of the NO synthesis inhibitor L-NAME.Epithelium-denuded tracheas showed a reduced relaxation response to Sal. L-NAME (1 mM) similarly decreased the sensitivity of the rat tracheas to Sal in both epithelium-intact and -denuded conditions. In the presence of L-NAME, high concentrations of Sal induced an unexpectedly large relaxation response in carbachol-stimulated rat tracheas with both intact and denuded epithelium. Sal relaxation was also affected by L-NAME in electrical field-stimulated epithelium-intact and -denuded tracheas.The results suggest that NO derived from sources other than the epithelium is an important mediator of the Sal-induced relaxation in rat tracheas.

Published
2009

7. Photometry and models of selected main belt asteroids. VII. 350 Ornamenta, 771 Libera, and 984 Gretia

Author

A. Peyrot, T. Kwiatkowski, Magdalena Polińska, F. Colas, S. Fauvaud, Krzysztof Kamiński, Tadeusz Michalowski, A. Marciniak, K. Sobkowiak, P. Descamps, Regina Rudawska, J.-P. Teng-Chuen-Yu, G. Santacana, M. Fauvaud, Agnieszka Kryszczyńska, A. Bruno, L. Bernasconi, Raoul Behrend, R. Hirsch, Adam Mickiewicz University in Poznań (UAM), Observatoire Astronomique de l'Université de Genève, Observatoire des Engarouines, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Groupe Astrométrie et Planétologie (GAP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Observatoire du Bois de Bardon, Association T60, Observatoire Midi-Pyrénées, Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Université de Rennes (UR), and Observatoire astronomique des Makes

Subjects
Photometry (optics), Physics, Space and Planetary Science, Planet, Asteroid, Asteroid belt, Astronomy, Astronomy and Astrophysics, Astrophysics, Light curve, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience; We analyze photometric observations of the three main-belt asteroids 350 Ornamenta, 771 Libera, and 984 Gretia, conducted over a twelve-year interval. Our data and those of other authors allow us to determine pole and shape models using the lightcurve inversion technique. In all three cases, a single pole solution was obtained without any significant mirror solution: Ornamenta - P = 9.180 414 h, lambdap = 184°, betap = -29° Libera - P = 5.890 423 h, lambdap = 64°, betap = -78° Gretia - P = 5.778 025 h, lambdap = 245°, betap = +52°. This analysis and the development of asteroid models increase the set of asteroids with known spin and shape parameters, which consists of only around 100 objects.

Published
2009
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8. Photometry and models of selected main belt asteroids. IV. 184 Dejopeja, 276 Adelheid, 556 Phyllis

Author

Magdalena Polińska, S. Fauvaud, Mikko Kaasalainen, Josef Ďurech, R. Hirsch, M. Fagas, R. Roy, Raoul Behrend, Agnieszka Kryszczyńska, T. Kwiatkowski, F. Colas, Krzysztof Kamiński, Tadeusz Michalowski, G. Santacana, A. Marciniak, Adam Mickiewicz University in Poznań (UAM), Rolf Nevanlinna Institute, Astronomical Institute, Charles University, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Groupe Astrométrie et Planétologie (GAP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Association AstroQueyras, Groupe européen d’observation stellaire (GEOS), Observatoire Astronomique de l'Université de Genève, and Observatoire de Blauvac

Subjects
Physics, 010504 meteorology & atmospheric sciences, Astronomy, Astronomy and Astrophysics, Astrophysics, Light curve, 01 natural sciences, Photometry (optics), Space and Planetary Science, Asteroid, Planet, 0103 physical sciences, Asteroid belt, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract

International audience; We report photometric lightcurve observations of 184 Dejopeja (apparition years: 2000, 2002, 2005, 2006), 276 Adelheid (2000, 2001, 2004, 2005, 2006), and 556 Phyllis (1998, 2000, 2002, 2004, 2005, 2006) carried out on 48 nights at four observatories. Using all of the available lightcurves, the spin vectors, senses of rotation, and shape models of these three asteroids have been determined.

Published
2007
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9. Exercise tolerance in a hot and humid climate in heat-acclimatized girls and women

Author

Anita M. Rivera-Brown, Farah A. Ramirez-Marrero, A. Vann, G. Santacana, and Thomas W. Rowland

Subjects
Adult, medicine.medical_specialty, Hot Temperature, Acclimatization, Physical Therapy, Sports Therapy and Rehabilitation, Physical exercise, Sweating, Cardiovascular Physiological Phenomena, Animal science, Heart rate, medicine, Humans, Orthopedics and Sports Medicine, Exercise physiology, Child, Exercise, Tropical Climate, Exercise Tolerance, Chemistry, Humidity, Water-Electrolyte Balance, Sports drink, Physical therapy, Forearm skin, Female, Hot and humid, Body Temperature Regulation
Abstract

This study compared physiological responses associated with exercise tolerance in girls (G) and women (W) of similar fitness and heat acclimatization level during exercise in a hot and humid outdoor environment (33.4 degrees C and 55.1 % RH; WBGT = 29.9 +/- 0.2 degrees C). Nine pre-menarcheal G (age = 11.3 yr) and nine W (age = 26.8 yr), matched for aerobic capacity and heat acclimatization level, performed a cycling session at 60 % VO2max until fatigue. A sports drink was provided periodically to prevent dehydration. Tolerance time was not different between the groups (G = 56.9 +/- 6.3, W = 76.5 +/- 9.9 min, p > 0.05). During exercise, sweat rate (G = 9.1 +/- 1.1, W = 12.0 +/- 1.1 ml.m(-2).min(-1)), the increase in rectal temperature [T(re)] (G = 0.9 +/- 0.1, W = 1.1 +/- 0.1 degrees C), and heat storage (G = 10.6 +/- 5.3, W = 20.5 +/- 4.5 W.m(-2)) did not differ between the groups. At fatigue, T(re) (G = 38.2 +/- 0.1, W = 38.4 +/- 0.1 degrees C), heart rate (G = 167.3 +/- 7.3, W = 171 +/- 3.3 beats.min(-1)), stroke index (G = 48.3 +/- 1.5, W = 52.4 +/- 1.8 ml.m(-2)), and forearm skin blood flow (G = 9.5 +/- 1.3, W = 11.7 +/- 1.5 ml.100 ml(- 1).min(-1)) did not differ between the groups. Similar to women, the main reasons reported by girls to stop exercising in the heat were localized leg fatigue and gluteus muscle discomfort. We conclude that heat-acclimatized girls exhibit an adequate cardiovascular and thermoregulatory adjustment while exercising in a hot and humid outdoor environment when hypohydration is prevented.

Published
2006

10. A comprehensive study of the SX Phoenicis star BL Camelopardalis

Author

J. A. Farrell, G. Klingenberg, J. J. Rives, J. Michelet, S. E. Robinson, J. P. Sareyan, A. Y. Zhou, S. Fauvaud, Michael D. Reed, G. Santacana, Elizandro Rodriguez, Ignasi Ribas, Laboratoire Gemini (LG), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, and Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Frequency analysis, Photosphere, 010308 nuclear & particles physics, Cepheid variable, Metallicity, Astronomy, Astronomy and Astrophysics, Orbital eccentricity, Astrophysics, Light curve, 01 natural sciences, law.invention, Amplitude, Space and Planetary Science, law, 0103 physical sciences, Variable star, 010303 astronomy & astrophysics
Abstract

Context. BL Cam is an extreme field multiperiodic short-period low-metallicity high-amplitude SX Phe-type variable where its probably complex pulsational content is subject of controversies. Aims. A comprehensive study has been carried out to investigate the nature and pulsational properties of this object. Methods. The analysis is based on new photometric data collected during the last few years at different sites, as well as on all available previously published data. Frequency analyses have been performed on a number of reliable data sets to analyse the pulsational content. In addition, the classical O−C method was used to study the behaviour of the main period. Results. Our frequency analysis confirms some aspects on the multiperiodicity of BL Cam, previously found by other authors, showing a number of secondary modes close to the main frequency f0 = 25.5769 cd −1 . The secondary modes present eventual amplitude variations. However, the main frequency exhibits no significant changes in its amplitude and seems to correspond to the fundamental mode of radial pulsation. Abrupt changes sometimes observed in the light curves could be due to spurious activity on or close to the star’s photosphere. We confirm the existence of a secondary frequency at 31.6 or 32.6 cd −1 , with variable amplitude, and with the possibility of both frequencies being intrinsic to the star. More than one hundred of new times of light maxima have been determined in the present work. These together with those available in the literature allow us a more discriminating analysis of the O–C diagram. This shows that the observed variations of the main period can be described by two terms: (i) a secular increase of the main period at a rate of dP/Pdt = 117(±3) × 10 −9 yr −1 ; and (ii) a perturbation from a companion star in a rather eccentric orbit with a period of 10.5(±0.2) yr causing a light time semi-amplitude of 148(±12) s.

Published
2006
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11. Chronic imipramine treatment induces downregulation of alpha-2 receptors in rat's locus coeruleus and A2 region of the tractus solitarius

Author

O. Segarra, C.A. Jimenez-Rivera, G. Santacana, Thomas J. Hoffman, Daniel D. Savage, and Gerald K. Weiss

Subjects
Male, medicine.medical_specialty, Imipramine, Population, Down-Regulation, Antidepressive Agents, Tricyclic, Amygdala, General Biochemistry, Genetics and Molecular Biology, Dioxanes, Rats, Sprague-Dawley, Idazoxan, Receptors, Adrenergic, alpha-2, Internal medicine, medicine, Solitary Nucleus, Animals, General Pharmacology, Toxicology and Pharmaceutics, Receptor, education, Adrenergic alpha-Antagonists, education.field_of_study, Chemistry, Imidazoles, General Medicine, Rats, Stria terminalis, Endocrinology, medicine.anatomical_structure, nervous system, Locus coeruleus, Autoradiography, Alpha-2 adrenergic receptor, Locus Coeruleus, Injections, Intraperitoneal, medicine.drug, Densitometry
Abstract

Imipramine is an effective antidepressant agent that blocks the reuptake of monoamines. In order to understand some of its basic mechanisms of action, we investigated the effects of chronic imipramine administration (10 mg/kg, i.p.; 21 days) on the alpha-2 receptor population of several brain sites. Alpha-2 receptor density was estimated by in vitro autoradiography using [3H]Idazoxan. The densitometric analysis revealed a decreased receptor density in the A2 region of the tractus solitarius (20%) and locus coeruleus (16%). No changes were observed in the amygdala, pyriform cortex, periacueductal gray and the bed nucleus of the stria terminalis. These results suggest that chronic imipramine treatment selectively modulates the alpha-2 receptor population localized in the brain stem norepinephrine-rich nuclei and not in the population present on limbic structures innervated by noradrenergic terminal projections. The possible physiological consequences of this selective modulation of alpha-2 receptors are discussed.

Published
1996

12. EXERCISE TOLERANCE IN HOT AND HUMID CLIMATE

Author

F. A. Ram rez-Marrero, A. Vann, Anita M. Rivera-Brown, Thomas W. Rowland, and G. Santacana

Subjects
Animal science, Environmental science, Physical Therapy, Sports Therapy and Rehabilitation, Orthopedics and Sports Medicine, Hot and humid
Published
2003
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13. Role of Na+ and Ca++ in Guinea Pig Trachealis Contraction Induced by Cooling

Author

G. Santacana and W.Y. Chen

Subjects
Pulmonary and Respiratory Medicine, medicine.medical_specialty, Contraction (grammar), business.industry, Sodium, chemistry.chemical_element, Calcium, Amiloride, Guinea pig, Endocrinology, chemistry, Internal medicine, Extracellular, medicine, Trachealis muscle, Biophysics, medicine.symptom, business, medicine.drug, Muscle contraction
Abstract

The role of extracellular Na+ and Ca++ in cooling-induced contraction (CIC) was studied in guinea pig trachealis muscle. Tracheal preparations were tested in Krebs-Ringer bicarbo

Published
1988
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14. The pulmonary ethanol metabolizing system (PET)

Author

J, Bernstein, B, Martínez, N, Escobales, and G, Santacana

Subjects
Male, Ethanol, Antimetabolites, Glucuronates, Rats, Inbred Strains, Acetaldehyde, In Vitro Techniques, Rats, Alcohol Oxidoreductases, Oxygen Consumption, Species Specificity, Microsomes, Animals, Lung, Oxidation-Reduction
Abstract

Rat lung slices incubated in a Krebs ringer bicarbonate buffer respired at a rate of 0.62 mumoles/g lung X min. Respiration was inhibited by cyanide and stimulated by dinitrophenol. PET was insensitive to the action of pyrazole, cyanide or azide. Lung microsomes metabolized ethanol at rates which were less than 1% of PET. They showed an apparent Km for ethanol of the order of 10 mM and a Vmax of about 7 nmoles acetaldehyde/mg prot X min. Oxidation of ethanol by lung slices to acetaldehyde and CO2 was less than 0.3% and 1.15% than PET, respectively. Chromatographic determination of the products of ethanol metabolism by lung slices showed that a metabolite similar to glucuronic acid was formed. It is concluded that PET is a nonoxidative process which from the evidence presented in this work, would seem to involve the formation of ethyl glucuronide.

Published
1983

15. Effects of ethanol on calcium transport across the liver cell plasma membrane

Author

J, Bernstein and G, Santacana

Subjects
Male, Ethanol, Calcium Radioisotopes, Cell Membrane, Sodium, Biological Transport, Rats, Inbred Strains, In Vitro Techniques, Rats, Amiloride, Kinetics, Liver, Animals, Calcium, Ouabain, Carbon Tetrachloride
Abstract

The effect of ethanol on calcium transport by the liver cell was studied by using a rat liver slice preparation. Ethanol was shown to decrease by about 30% the rate constant for 45Ca efflux from the intracellular compartment. This inhibitory effect of ethanol was not observed in the absence of Ca2+ or Na+ from the incubation medium. Ethanol was also shown to greatly increase non-insulin calcium uptake by liver slices. This effect of ethanol appeared to be dose dependent and was not observed in the absence of Na+ from the incubation medium. The ability of ethanol to increase calcium uptake by the hepatocyte was completely blocked by 1 mM Amiloride. Amiloride, however, did not affect the increased entry of either Na+ or Ca2+ produced by 10 mM Ouabain, a specific inhibitor of the sodium pump. Carbon tetrachloride (CCl4), a well known hepatotoxin, also increased calcium uptake by the hepatocyte. Amiloride, however, was not able to block the CCl4-induced calcium uptake. These results suggest that ethanol activates a Na+ entry pathway, probably represented by a Na+/H+ exchanger, which in turn stimulates an entry of Ca2+ through a Na+/Ca2+ exchange mechanism located in the plasma membrane of the hepatocyte.

Published
1987

16. The Na+/Ca2+ exchange system of the liver cell

Author

J, Bernstein and G, Santacana

Subjects
Male, Sodium Radioisotopes, Calcium Radioisotopes, Cell Membrane, Sodium, Gramicidin, Biological Transport, Active, Rats, Inbred Strains, In Vitro Techniques, Rats, Ion Exchange, Liver, Lanthanum, Animals, Calcium, Ouabain
Abstract

The efflux of 45Ca (Caeff) from rat liver slices incubated in a Krebs Ringer bicarbonate buffer showed two components with first order rate constants (kCa) of 0.0625 min-1 and 0.0101 min-1 respectively. The slow component corresponds to Caeff from the intracellular medium. Ouabain decreased kCa from the slow component (ksCa) by about 30%. External Na+ or Ca2+ did not affect ksCa. However, the inhibitory effect of ouabain was not observed in the absence of either Na+ or Ca2+ from the incubation medium. Concomitant to a decrease in ksCa, ouabain increased 45Ca uptake (Caup) by about 30%. Sodium ionophores also increased Caup, an effect which was not observed in the absence of external Na+. 22Na efflux was inhibited 50% by ouabain. In the presence of ouabain, external Ca2+ was able to significantly increase ksNa from 0.0475 min-1 to 0.0506 min-1. External Na+ dit not affect ksCa from preloaded slices containing high calcium and low sodium when incubated in a Ca2+-free medium. These results would indicate that a Na+/Ca2+ exchange system in operative in the plasma membrane of the hepatocyte. It is estimated that about 60% of the calcium entering the hepatocyte moves in through this exchanger. The evidence obtained also suggests that the Na+/Ca2+ exchanger operates unidirectionally, extruding internal Na+ in exchange for external Ca2+.

Published
1985

18. Nanoparticle-Mediated In Situ Molecular Reprogramming of Immune Checkpoint Interactions for Cancer Immunotherapy.

Author

Walters AA, Santacana-Font G, Li J, Routabi N, Qin Y, Claes N, Bals S, Tzu-Wen Wang J, and Al-Jamal KT

Abstract

Immune checkpoint blockade involves targeting immune regulatory molecules with antibodies. Preclinically, complex multiantibody regimes of both inhibitory and stimulatory targets are a promising candidate for the next generation of immunotherapy. However, in this setting, the antibody platform may be limited due to excessive toxicity caused by off target effects as a result of systemic administration. RNA can be used as an alternate to antibodies as it can both downregulate immunosuppressive checkpoints (siRNA) or induce expression of immunostimulatory checkpoints (mRNA). In this study, we demonstrate that the combination of both siRNA and mRNA in a single formulation can simultaneously knockdown and induce expression of immune checkpoint targets, thereby reprogramming the tumor microenvironment from immunosuppressive to immunostimulatory phenotype. To achieve this, RNA constructs were synthesized and formulated into stable nucleic acid lipid nanoparticles (SNALPs); the SNALPs produced were 140-150 nm in size with >80% loading efficiency. SNALPs could transfect macrophages and B16F10 cells in vitro resulting in 75% knockdown of inhibitory checkpoint (PDL1) expression and simultaneously express high levels of stimulatory checkpoint (OX40L) with minimal toxicity. Intratumoral treatment with the proposed formulation resulted in statistically reduced tumor growth, a greater density of CD4+ and CD8+ infiltrates in the tumor, and immune activation within tumor-draining lymph nodes. These data suggest that a single RNA-based formulation can successfully reprogram multiple immune checkpoint interactions on a cellular level. Such a candidate may be able to replace future immune checkpoint therapeutic regimes composed of both stimulatory- and inhibitory-receptor-targeting antibodies.

Published
2021
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19. REPAIRit: Improving Myocardial Nulling and Ghosting Artifacts of 3D Navigator-Gated Late Gadolinium Enhancement Imaging During Arrhythmia.

Author

Hu C, Huber S, Latif SR, Santacana-Laffitte G, Mojibian HR, Baldassarre LA, and Peters DC

Subjects
Adult, Aged, Artifacts, Contrast Media chemistry, Female, Heart diagnostic imaging, Humans, Image Enhancement methods, Image Interpretation, Computer-Assisted methods, Imaging, Three-Dimensional methods, Male, Middle Aged, Myocardium pathology, Phantoms, Imaging, Prospective Studies, Signal-To-Noise Ratio, Arrhythmias, Cardiac diagnostic imaging, Cardiac Imaging Techniques, Gadolinium chemistry, Magnetic Resonance Imaging, Myocardium metabolism
Abstract

Background: Cardiac 3D navigator-gated late gadolinium enhancement (LGE) imaging is important for assessment of left atrial fibrosis, but the image quality is often degraded due to arrhythmia., Purpose: To investigate a novel 3D LGE sequence with improved myocardial nulling and reduced ghosting artifacts during arrhythmia., Study Type: Prospective., Population: Arrhythmia patients (n = 14)., Sequence: The proposed technique, REPAIRit (Regrowth Equalization Pulse for Arrhythmias in Inversion Recovery with automatic inversion time calculation), inserts a saturation pulse with a dynamic flip angle into the 3D LGE sequence to minimize arrhythmia-induced signal fluctuations. Using ShMOLLI (shortened modified Look-Locker imaging) to estimate myocardial T 1 , REPAIRit automatically calculates the optimal inversion time (TI) based on Bloch equations., Assessment: REPAIRit LGE and the standard LGE were compared with simulations, phantom imaging, and patient studies. Patient images were assessed quantitatively, based on ghost-to-noise ratio (GNR), blood signal-to-noise ratio (SNRb), myocardial signal-to-noise ratio (SNRm), and blood-to-myocardium contrast-to-noise ratio (CNR), and qualitatively on a 4-point scale. Patients were subgrouped based on the presence of arrhythmia to assess the image quality difference., Statistical Tests: The two LGE sequences were compared by Student's t-test and Wilcoxon signed-rank test. The two patient-subgroups were compared using Welch's t-test and Wilcoxon rank-sum test., Results: In 14 analyzed patients, REPAIRit LGE significantly lowered GNR (1.25 ± 0.41 vs. 1.42 ± 0.42, P = 0.04), reduced SNRm (1.90 ± 0.60 vs. 3.16 ± 1.66, P = 0.01), improved ghosting artifact scores (2.5 ± 0.6 vs. 2.2 ± 0.9, P = 0.03), myocardial nulling scores (2.7 ± 0.5 vs. 2.3 ± 0.7, P = 0.02), and atrial quality scores (2.8 ± 0.3 vs. 2.4 ± 0.8, P = 0.03) compared with the standard LGE. Comparing patients with arrhythmia (n = 6) to those without (n = 8) during the scan, the former had lower left ventricular (LV) myocardial T 1 s (430 ± 26 msec vs. 469 ± 39 msec, P = 0.06) but similar blood T 1 s (318 ± 55 msec vs. 316 ± 27 msec, P = 0.96), and significantly lower blood SNR (5.2 ± 1.8 vs. 9.2 ± 3.0, P = 0.01) and significantly worse image quality (P = 0.01 for REPAIRit and P = 0.03 for standard)., Data Conclusion: REPAIRit improves myocardial nulling and reduces ghosting artifacts of 3D LGE under arrhythmia., Level of Evidence: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:688-699., (© 2018 International Society for Magnetic Resonance in Medicine.)

Published
2019
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20. Does MR enterography offer added value after a recent CT in the evaluation of abdominal pain in Crohn's disease patients?

Author

Spektor M, Mathur M, Santacana G, Asch D, Huber S, Staib L, and Israel G

Subjects
Abdomen diagnostic imaging, Abdominal Pain etiology, Abscess diagnostic imaging, Adult, Constriction, Pathologic, Female, Humans, Intestinal Obstruction, Intestines diagnostic imaging, Intestines pathology, Pelvis diagnostic imaging, Radiography, Abdominal, Sensitivity and Specificity, Tomography, X-Ray Computed methods, Young Adult, Abdominal Pain diagnostic imaging, Crohn Disease complications, Magnetic Resonance Imaging methods
Abstract

Purpose: To determine if there is added value in performing MR enterography shortly after a contrast-enhanced CT of the abdomen and pelvis in patients with Crohn's disease presenting with acute abdominal pain., Materials and Methods: A total of 45 consecutive patients who underwent MRE examination <7 days after a CT met our strict inclusion criteria. Independent and blinded review of both MRE and CT exams was performed by two abdominal radiologists., Results: There were no significant differences in detection of various findings associated with Crohn's disease between modalities. These findings included abscess, fistula, bowel wall thickening, free fluid, stricture, and bowel obstruction. There was moderate interobserver agreement with CT (Kappa: 0.52, 95% CI: [0.4-0.6]) and fair with MRE (Kappa: 0.36, 95% CI:[0.3 = 0.5])., Conclusion: The routine use of MRE after a diagnostic CT should be avoided, as it provides no additional valuable information, at the expense of extra patient risks, discomfort, and higher health care costs., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Published
2019
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21. Reverse double inversion-recovery: Improving motion robustness of cardiac T 2 -weighted dark-blood turbo spin-echo sequence.

Author

Hu C, Huber S, Latif SR, Santacana-Laffitte G, Mojibian HR, Baldassarre LA, and Peters DC

Subjects
Adult, Aged, Algorithms, Artifacts, Computer Simulation, Diastole, Female, Healthy Volunteers, Heart Ventricles diagnostic imaging, Humans, Image Enhancement methods, Image Interpretation, Computer-Assisted methods, Male, Middle Aged, Prospective Studies, Quality Control, Reproducibility of Results, Signal-To-Noise Ratio, Heart diagnostic imaging, Heart Diseases diagnostic imaging, Image Processing, Computer-Assisted methods, Magnetic Resonance Imaging, Motion, Myocardium pathology
Abstract

Background: Cardiac dark-blood turbo spin-echo (TSE) imaging is sensitive to through-plane motion, resulting in myocardial signal reduction., Purpose: To propose and validate reverse double inversion-recovery (RDIR)-a dark-blood preparation with improved motion robustness for the cardiac dark-blood TSE sequence., Study Type: Prospective., Population: Healthy volunteers (n = 10) and patients (n = 20)., Field Strength: 1.5T (healthy volunteers) and 3T (patients)., Assessment: Compared to double inversion recovery (DIR), RDIR swaps the two inversion pulses in time and places the slice-selective 180° in late-diastole of the previous cardiac cycle to minimize slice misregistration. RDIR and DIR were performed in the same left-ventricular basal short-axis slice. Healthy subjects were imaged with two preparation slice thicknesses, 110% and 200%, while patients were imaged using a 200% slice thickness only. Images were assessed quantitatively, by measuring the myocardial signal heterogeneity and the extent of dropout, and also qualitatively on a 5-point scale., Statistical Tests: Quantitative and qualitative data were assessed with Student's t-test and Wilcoxon signed-rank test, respectively., Results: In healthy subjects, RDIR with 110% slice thickness significantly reduced signal heterogeneity in both the left ventricle (LV) and right ventricle (RV) (LV: P = 0.006, RV: P < 0.0001) and the extent of RV dropout (P < 0.0001), while RDIR with 200% slice thickness significantly reduced RV signal heterogeneity (P = 0.001) and the extent of RV dropout (P = 0.0002). In patients, RDIR significantly reduced RV myocardial signal heterogeneity (0.31 vs. 0.43; P = 0.003) and the extent of RV dropout (24% vs. 46%; P = 0.0005). LV signal heterogeneity exhibited a trend towards improvement with RDIR (0.12 vs. 0.16; P = 0.06). Qualitative evaluation showed a significant improvement of LV and RV visualization in RDIR compared to DIR (LV: P = 0.04, RV: P = 0.0007) and a significantly improved overall image quality (P = 0.03)., Data Conclusion: RDIR TSE is less sensitive to through-plane motion, potentiating increased clinical utility for black-blood TSE., Level of Evidence: 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:1498-1508., (© 2017 International Society for Magnetic Resonance in Medicine.)

Published
2018
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23. Radiography of cardiac conduction devices: a pictorial review of pacemakers and implantable cardioverter defibrillators.

Author

Torres-Ayala SC, Santacana-Laffitte G, and Maldonado J

Abstract

Cardiac conduction devices (CCDs) depend on correct anatomic positioning to function properly. Chest radiography is the preferred imaging modality to evaluate CCD's anatomic location, lead wire integrity, and help in identifying several complications. In this pictorial review, our goal is to familiarize radiologists with CCD implantation techniques, appropriate positioning of the device, common causes of malfunction, methods to improve report accuracy, and assure maximal therapeutic benefit.

Published
2014
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24. Cystic adnexal mass in a 16-year-old female: Ovarian pathology or complication of a Müllerian anomaly?

Author

Santacana-Laffitte G, Ruiz L, Pedrogo Y, and Colon E

Abstract

Patient: Female, 16 Final Diagnosis: Pelvic mass Symptoms: None Medication: None Clinical Procedure: CT • MRI Specialty: Diagnostic radiology • pediatrics., Objective: Unusual presentation of unknown etiology, Rare disease, Mistake in diagnosis., Background: Müllerian anomalies encompass a wide variety of malformations in the female genital tract, usually associated with renal and anorectal malformations. Of these anomalies, approximately 11% are uterus didelphys, which occurs when midline fusion of the müllerian ducts is arrested to a variable extent., Case Report: We report the case of a 16-year-old female with uterine didelphys, jejunal malrotation, hematometra, hematosalpinx, and bilateral subcentimeter homogenous circular cystic-like renal lesions, who initially presented with left lower quadrant abdominal pain, non-bloody vomiting, and a history of irregular menstrual periods. Initial CT was confusing for an adnexal cystic mass, but further imaging disclosed the above müllerian anomalies., Conclusions: Müllerian anomalies may mimic other, more common, adnexal lesions; thus, adequate evaluation of suspicious cystic adnexal masses with multiple and advanced imaging modalities such as MRI is essential for adequate diagnosis and management.

Published
2013
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25. Nitric oxide is involved in the response of the isolated intact and epithelium-denuded rat trachea to the β₂ adrenergic receptor agonist salbutamol.

Author

Montalvo F, Cantres-Fonseca O, Santos G, Vega M, Torres I, Carmona J, Dexter D, and Santacana G

Subjects
Animals, Carbachol pharmacology, Cholinergic Agonists pharmacology, Electric Stimulation, Epithelium surgery, Male, Muscle Relaxation drug effects, Muscle, Smooth drug effects, Rats, Rats, Sprague-Dawley, Trachea surgery, Adrenergic beta-2 Receptor Agonists pharmacology, Albuterol pharmacology, Enzyme Inhibitors pharmacology, Epithelium drug effects, NG-Nitroarginine Methyl Ester pharmacology, Trachea drug effects
Abstract

Background: The involvement of the airway smooth muscle mediator nitric oxide (NO) in the actions of the β₂ agonist salbutamol (Sal), a well-known bronchodilator, is very poorly understood., Objectives: To determine if endogenous NO release is a major factor in the Sal-induced relaxation of the carbachol- and electrical field-stimulated rat trachea and determine the role of the tracheal epithelium as the possible source of NO involved in these effects., Methods: Isolated carbachol- or electric field-stimulated pre-contracted in vitro male Sprague Dawley rat tracheas (with epithelium intact or denuded) were relaxed with incremental or discrete concentrations of Sal in the presence and absence of the NO synthesis inhibitor L-NAME., Results: Epithelium-denuded tracheas showed a reduced relaxation response to Sal. L-NAME (1 mM) similarly decreased the sensitivity of the rat tracheas to Sal in both epithelium-intact and -denuded conditions. In the presence of L-NAME, high concentrations of Sal induced an unexpectedly large relaxation response in carbachol-stimulated rat tracheas with both intact and denuded epithelium. Sal relaxation was also affected by L-NAME in electrical field-stimulated epithelium-intact and -denuded tracheas., Conclusion: The results suggest that NO derived from sources other than the epithelium is an important mediator of the Sal-induced relaxation in rat tracheas., (Copyright © 2010 S. Karger AG, Basel.)

Published
2010
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26. Identification of nerve plexi in connective tissues of the sea cucumber Holothuria glaberrima by using a novel nerve-specific antibody.

Author

Díaz-Balzac CA, Santacana-Laffitte G, San Miguel-Ruíz JE, Tossas K, Valentín-Tirado G, Rives-Sánchez M, Mesleh A, Torres II, and García-Arrarás JE

Subjects
Animals, Antibodies, Monoclonal metabolism, Antigens metabolism, Epidermis metabolism, Holothuria immunology, Holothuria metabolism, Nervous System anatomy & histology, Nervous System immunology, Nervous System metabolism, Radial Nerve metabolism, Connective Tissue innervation, Holothuria anatomy & histology
Abstract

The echinoderm nervous system is one of the least studied among invertebrates, partly because the tools available to study the neurobiology of this phylum are limited. We have now produced a monoclonal antibody (RN1) that labels a nervous system component of the sea cucumber Holothuria glaberrima. Western blots show that our antibody recognizes a major band of 66 kDa and a minor band of 53 kDa. Immunohistological experiments show that, in H. glaberrima, the antibody distinctly labels most of the known nervous system structures and some components that were previously unknown or little studied. A surprising finding was the labeling of nervous plexi within the connective tissue compartments of all organs studied. Double labeling with holothurian neuropeptides and an echinoderm synaptotagmin showed that RN1 labeled most, if not all, of the fibers labeled by these neuronal markers, but also a larger component of cells and fibers. The presence of a distinct connective tissue plexus in holothurians is highly significant since these organisms possess mutable connective tissues that change viscosity under the control of the nervous system. Therefore, the cells and fibers recognized by our monoclonal antibodies may be involved in controlling tensility changes in echinoderm connective tissue.

Published
2007
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27. Preparation and assessment of glutaraldehyde-crosslinked collagen-chitosan hydrogels for adipose tissue engineering.

Author

Wu X, Black L, Santacana-Laffitte G, and Patrick CW Jr

Subjects
Adipocytes metabolism, Adipose Tissue growth & development, Animals, Cell Differentiation, Male, Materials Testing standards, Neovascularization, Physiologic, Rats, Rats, Inbred Lew, Absorbable Implants, Adipocytes cytology, Chitosan, Collagen, Glutaral, Tissue Engineering
Abstract

A portfolio of crosslinked chitosan:collagen blends was prepared, and their microarchitecture and water binding capacity were studied to investigate their application for adipose tissue engineering. Glutaraldehyde (GA) concentration had little effect on scaffold morphology or water binding capacity. However, the processing freezing temperature prior to lyophilization affected both. In vitro cytocompatibility of pre-adipocytes (PAs) was assessed for a candidate collagen:chitosan blend using two assays. Results confirm the viability of PAs on GA-crosslinked collagen:chitosan scaffolds. A rat subcutaneous pocket assay was employed to assess PA-seeded scaffolds in vivo. Animal tests proved that PA-seeded scaffolds were biocompatible, could induce vascularization, and form adipose tissue., ((c) 2006 Wiley Periodicals, Inc.)

Published
2007
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28. Juvenile cataracts in a patient with histidinuria: case report.

Author

Santacana-Laffitte G, Izquierdo NJ, Lladó JR, and Maumenee IH

Subjects
Adolescent, Amino Acid Metabolism, Inborn Errors blood, Amino Acid Metabolism, Inborn Errors urine, Female, Histidine blood, Humans, Lens Implantation, Intraocular, Phacoemulsification, Amino Acid Metabolism, Inborn Errors complications, Cataract etiology, Histidine urine
Published
2006
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29. Exercise tolerance in a hot and humid climate in heat-acclimatized girls and women.

Author

Rivera-Brown AM, Rowland TW, Ramírez-Marrero FA, Santacana G, and Vann A

Subjects
Adult, Cardiovascular Physiological Phenomena, Child, Female, Hot Temperature, Humans, Humidity, Sweating, Water-Electrolyte Balance physiology, Acclimatization, Body Temperature Regulation physiology, Exercise physiology, Exercise Tolerance physiology, Tropical Climate
Abstract

This study compared physiological responses associated with exercise tolerance in girls (G) and women (W) of similar fitness and heat acclimatization level during exercise in a hot and humid outdoor environment (33.4 degrees C and 55.1 % RH; WBGT = 29.9 +/- 0.2 degrees C). Nine pre-menarcheal G (age = 11.3 yr) and nine W (age = 26.8 yr), matched for aerobic capacity and heat acclimatization level, performed a cycling session at 60 % VO2max until fatigue. A sports drink was provided periodically to prevent dehydration. Tolerance time was not different between the groups (G = 56.9 +/- 6.3, W = 76.5 +/- 9.9 min, p > 0.05). During exercise, sweat rate (G = 9.1 +/- 1.1, W = 12.0 +/- 1.1 ml.m(-2).min(-1)), the increase in rectal temperature [T(re)] (G = 0.9 +/- 0.1, W = 1.1 +/- 0.1 degrees C), and heat storage (G = 10.6 +/- 5.3, W = 20.5 +/- 4.5 W.m(-2)) did not differ between the groups. At fatigue, T(re) (G = 38.2 +/- 0.1, W = 38.4 +/- 0.1 degrees C), heart rate (G = 167.3 +/- 7.3, W = 171 +/- 3.3 beats.min(-1)), stroke index (G = 48.3 +/- 1.5, W = 52.4 +/- 1.8 ml.m(-2)), and forearm skin blood flow (G = 9.5 +/- 1.3, W = 11.7 +/- 1.5 ml.100 ml(- 1).min(-1)) did not differ between the groups. Similar to women, the main reasons reported by girls to stop exercising in the heat were localized leg fatigue and gluteus muscle discomfort. We conclude that heat-acclimatized girls exhibit an adequate cardiovascular and thermoregulatory adjustment while exercising in a hot and humid outdoor environment when hypohydration is prevented.

Published
2006
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30. Chronic imipramine treatment induces downregulation of alpha-2 receptors in rat's locus coeruleus and A2 region of the tractus solitarius.

Author

Jiménez-Rivera CA, Segarra O, Santacana G, Hoffman T, Savage DD, and Weiss GK

Subjects
Adrenergic alpha-Antagonists metabolism, Animals, Antidepressive Agents, Tricyclic administration & dosage, Autoradiography, Densitometry, Dioxanes metabolism, Down-Regulation drug effects, Idazoxan, Imidazoles metabolism, Imipramine administration & dosage, Injections, Intraperitoneal, Locus Coeruleus drug effects, Male, Rats, Rats, Sprague-Dawley, Solitary Nucleus drug effects, Antidepressive Agents, Tricyclic pharmacology, Imipramine pharmacology, Locus Coeruleus metabolism, Receptors, Adrenergic, alpha-2 metabolism, Solitary Nucleus metabolism
Abstract

Imipramine is an effective antidepressant agent that blocks the reuptake of monoamines. In order to understand some of its basic mechanisms of action, we investigated the effects of chronic imipramine administration (10 mg/kg, i.p.; 21 days) on the alpha-2 receptor population of several brain sites. Alpha-2 receptor density was estimated by in vitro autoradiography using [3H]Idazoxan. The densitometric analysis revealed a decreased receptor density in the A2 region of the tractus solitarius (20%) and locus coeruleus (16%). No changes were observed in the amygdala, pyriform cortex, periacueductal gray and the bed nucleus of the stria terminalis. These results suggest that chronic imipramine treatment selectively modulates the alpha-2 receptor population localized in the brain stem norepinephrine-rich nuclei and not in the population present on limbic structures innervated by noradrenergic terminal projections. The possible physiological consequences of this selective modulation of alpha-2 receptors are discussed.

Published
1996
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31. Role of Na+ and Ca++ in guinea pig trachealis contraction induced by cooling.

Author

Santacana G and Chen WY

Subjects
Acetylcholine pharmacology, Amiloride pharmacology, Animals, Cold Temperature, Female, Guinea Pigs, In Vitro Techniques, Ions, Male, Nifedipine pharmacology, Calcium physiology, Muscle Contraction drug effects, Sodium physiology, Trachea physiology
Abstract

The role of extracellular Na+ and Ca++ in cooling-induced contraction (CIC) was studied in guinea pig trachealis muscle. Tracheal preparations were tested in Krebs-Ringer bicarbonate (KRB) solution and then in either: (1) a low Na+ sucrose KRB, (2) KRB plus amiloride, a sodium channel blocker, or (3) KRB plus nifedipine, a calcium channel blocker. When the trachealis muscle was cooled from 37 to 20 degrees C in KRB, the value of the isometric tension increased on average by 25% of the maximal tension induced by acetylcholine; however, when the tissue was tested in the low Na+ sucrose KRB or the KRB containing amiloride, CIC was totally prevented. In the presence of nifedipine the mean value of CIC was only 10% of the acetylcholine-induced contraction, which was also observed not to be affected by extracellular Na+ or Ca++; whereas the KCl-induced contraction was affected by Ca++ but not by Na+. The results suggest that rapid cooling of the smooth muscle cells causes an increase in sodium conductance and a decrease in the activity of the Na+-K+ pump, resulting in membrane depolarization. During depolarization a significant quantity of Ca++ enters the cell, contributing to the magnitude of CIC.

Published
1988
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32. Effects of ethanol on calcium transport across the liver cell plasma membrane.

Author

Bernstein J and Santacana G

Subjects
Amiloride pharmacology, Animals, Biological Transport drug effects, Calcium Radioisotopes, Carbon Tetrachloride pharmacology, Cell Membrane drug effects, Cell Membrane metabolism, In Vitro Techniques, Kinetics, Male, Ouabain pharmacology, Rats, Rats, Inbred Strains, Sodium metabolism, Calcium metabolism, Ethanol pharmacology, Liver metabolism
Abstract

The effect of ethanol on calcium transport by the liver cell was studied by using a rat liver slice preparation. Ethanol was shown to decrease by about 30% the rate constant for 45Ca efflux from the intracellular compartment. This inhibitory effect of ethanol was not observed in the absence of Ca2+ or Na+ from the incubation medium. Ethanol was also shown to greatly increase non-insulin calcium uptake by liver slices. This effect of ethanol appeared to be dose dependent and was not observed in the absence of Na+ from the incubation medium. The ability of ethanol to increase calcium uptake by the hepatocyte was completely blocked by 1 mM Amiloride. Amiloride, however, did not affect the increased entry of either Na+ or Ca2+ produced by 10 mM Ouabain, a specific inhibitor of the sodium pump. Carbon tetrachloride (CCl4), a well known hepatotoxin, also increased calcium uptake by the hepatocyte. Amiloride, however, was not able to block the CCl4-induced calcium uptake. These results suggest that ethanol activates a Na+ entry pathway, probably represented by a Na+/H+ exchanger, which in turn stimulates an entry of Ca2+ through a Na+/Ca2+ exchange mechanism located in the plasma membrane of the hepatocyte.

Published
1987

33. The pulmonary ethanol metabolizing system (PET).

Author

Bernstein J, Martínez B, Escobales N, and Santacana G

Subjects
Acetaldehyde metabolism, Alcohol Oxidoreductases metabolism, Animals, Antimetabolites pharmacology, Glucuronates metabolism, In Vitro Techniques, Male, Microsomes metabolism, Oxidation-Reduction, Oxygen Consumption drug effects, Rats, Rats, Inbred Strains, Species Specificity, Ethanol metabolism, Lung metabolism
Abstract

Rat lung slices incubated in a Krebs ringer bicarbonate buffer respired at a rate of 0.62 mumoles/g lung X min. Respiration was inhibited by cyanide and stimulated by dinitrophenol. PET was insensitive to the action of pyrazole, cyanide or azide. Lung microsomes metabolized ethanol at rates which were less than 1% of PET. They showed an apparent Km for ethanol of the order of 10 mM and a Vmax of about 7 nmoles acetaldehyde/mg prot X min. Oxidation of ethanol by lung slices to acetaldehyde and CO2 was less than 0.3% and 1.15% than PET, respectively. Chromatographic determination of the products of ethanol metabolism by lung slices showed that a metabolite similar to glucuronic acid was formed. It is concluded that PET is a nonoxidative process which from the evidence presented in this work, would seem to involve the formation of ethyl glucuronide.

Published
1983

34. The Na+/Ca2+ exchange system of the liver cell.

Author

Bernstein J and Santacana G

Subjects
Animals, Biological Transport, Active drug effects, Calcium Radioisotopes, Cell Membrane metabolism, Gramicidin pharmacology, In Vitro Techniques, Ion Exchange, Lanthanum pharmacology, Male, Ouabain pharmacology, Rats, Rats, Inbred Strains, Sodium Radioisotopes, Calcium metabolism, Liver metabolism, Sodium metabolism
Abstract

The efflux of 45Ca (Caeff) from rat liver slices incubated in a Krebs Ringer bicarbonate buffer showed two components with first order rate constants (kCa) of 0.0625 min-1 and 0.0101 min-1 respectively. The slow component corresponds to Caeff from the intracellular medium. Ouabain decreased kCa from the slow component (ksCa) by about 30%. External Na+ or Ca2+ did not affect ksCa. However, the inhibitory effect of ouabain was not observed in the absence of either Na+ or Ca2+ from the incubation medium. Concomitant to a decrease in ksCa, ouabain increased 45Ca uptake (Caup) by about 30%. Sodium ionophores also increased Caup, an effect which was not observed in the absence of external Na+. 22Na efflux was inhibited 50% by ouabain. In the presence of ouabain, external Ca2+ was able to significantly increase ksNa from 0.0475 min-1 to 0.0506 min-1. External Na+ dit not affect ksCa from preloaded slices containing high calcium and low sodium when incubated in a Ca2+-free medium. These results would indicate that a Na+/Ca2+ exchange system in operative in the plasma membrane of the hepatocyte. It is estimated that about 60% of the calcium entering the hepatocyte moves in through this exchanger. The evidence obtained also suggests that the Na+/Ca2+ exchanger operates unidirectionally, extruding internal Na+ in exchange for external Ca2+.

Published
1985

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