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Bauché S, O'Regan S, Azuma Y, Laffargue F, McMacken G, Sternberg D, Brochier G, Buon C, Bouzidi N, Topf A, Lacène E, Remerand G, Beaufrere AM, Pebrel-Richard C, Thevenon J, El Chehadeh-Djebbar S, Faivre L, Duffourd Y, Ricci F, Mongini T, Fiorillo C, Astrea G, Burloiu CM, Butoianu N, Sandu C, Servais L, Bonne G, Nelson I, Desguerre I, Nougues MC, Bœuf B, Romero N, Laporte J, Boland A, Lechner D, Deleuze JF, Fontaine B, Strochlic L, Lochmuller H, Eymard B, Mayer M, Nicole S. Impaired Presynaptic High-Affinity Choline Transporter Causes a Congenital Myasthenic Syndrome with Episodic Apnea. Am J Hum Genet 2016; 99:753-761. [PMID: 27569547 DOI: 10.1016/j.ajhg.2016.06.033] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 06/29/2016] [Indexed: 12/21/2022] Open
Abstract
The neuromuscular junction (NMJ) is one of the best-studied cholinergic synapses. Inherited defects of peripheral neurotransmission result in congenital myasthenic syndromes (CMSs), a clinically and genetically heterogeneous group of rare diseases with fluctuating fatigable muscle weakness as the clinical hallmark. Whole-exome sequencing and Sanger sequencing in six unrelated families identified compound heterozygous and homozygous mutations in SLC5A7 encoding the presynaptic sodium-dependent high-affinity choline transporter 1 (CHT), which is known to be mutated in one dominant form of distal motor neuronopathy (DHMN7A). We identified 11 recessive mutations in SLC5A7 that were associated with a spectrum of severe muscle weakness ranging from a lethal antenatal form of arthrogryposis and severe hypotonia to a neonatal form of CMS with episodic apnea and a favorable prognosis when well managed at the clinical level. As expected given the critical role of CHT for multisystemic cholinergic neurotransmission, autonomic dysfunctions were reported in the antenatal form and cognitive impairment was noticed in half of the persons with the neonatal form. The missense mutations induced a near complete loss of function of CHT activity in cell models. At the human NMJ, a delay in synaptic maturation and an altered maintenance were observed in the antenatal and neonatal forms, respectively. Increased synaptic expression of butyrylcholinesterase was also observed, exposing the dysfunction of cholinergic metabolism when CHT is deficient in vivo. This work broadens the clinical spectrum of human diseases resulting from reduced CHT activity and highlights the complexity of cholinergic metabolism at the synapse.
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Affiliation(s)
- Stéphanie Bauché
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, 75013 Paris, France
| | - Seana O'Regan
- Membrane transport group, Neurophotonics Laboratory, CNRS UMR8250, Sorbonne Paris Cité-Paris Descartes University, 75005 Paris, France
| | - Yoshiteru Azuma
- The John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Fanny Laffargue
- Service de Génétique Médicale, Centre de référence Auvergne-Limousin, Neuropathies Périphériques Rares et Maladies Neuromusculaires, Centre Hospitalier Universitaire de Clermont-Ferrand, 63000 Clermont-Ferrand, France
| | - Grace McMacken
- The John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Damien Sternberg
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, 75013 Paris, France; AP-HP, Hôpital Pitié-Salpêtrière, 75013 Paris, France
| | - Guy Brochier
- AP-HP, Hôpital Pitié-Salpêtrière, 75013 Paris, France; Unité de pathologies neuromusculaires, Institut de Myologie, Sorbonne Universités, UPMC Université Paris 06 UMRS 974, Inserm U974, CNRS UMR 7215, 75013 Paris, France
| | - Céline Buon
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, 75013 Paris, France
| | - Nassima Bouzidi
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, 75013 Paris, France
| | - Ana Topf
- The John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Emmanuelle Lacène
- AP-HP, Hôpital Pitié-Salpêtrière, 75013 Paris, France; Unité de pathologies neuromusculaires, Institut de Myologie, Sorbonne Universités, UPMC Université Paris 06 UMRS 974, Inserm U974, CNRS UMR 7215, 75013 Paris, France
| | - Ganaelle Remerand
- Service de Néonatologie, Centre Hospitalier Universitaire de Clermont-Ferrand, 63000 Clermont-Ferrand, France
| | - Anne-Marie Beaufrere
- Service d'Anatomie et Cytologie pathologiques, Centre Hospitalier Universitaire de Clermont-Ferrand, 63000 Clermont-Ferrand, France
| | - Céline Pebrel-Richard
- Service de Cytogénétique Médicale, Centre Hospitalier Universitaire de Clermont-Ferrand, 63000 Clermont-Ferrand, France
| | - Julien Thevenon
- Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (TRANSLAD), Centre Hospitalier Universitaire Dijon, 21079 Dijon, France; Centre de Génétique et Centre de Référence Anomalies du Développement et Syndromes Malformatifs de l'Inter-région Est, Centre Hospitalier Universitaire Dijon, 21079 Dijon, France
| | - Salima El Chehadeh-Djebbar
- Service de génétique médicale, Institut de génétique médicale d'Alsace (IGMA), Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, 67098 Strasbourg, France
| | - Laurence Faivre
- Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (TRANSLAD), Centre Hospitalier Universitaire Dijon, 21079 Dijon, France; Centre de Génétique et Centre de Référence Anomalies du Développement et Syndromes Malformatifs de l'Inter-région Est, Centre Hospitalier Universitaire Dijon, 21079 Dijon, France
| | - Yannis Duffourd
- Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (TRANSLAD), Centre Hospitalier Universitaire Dijon, 21079 Dijon, France
| | - Federica Ricci
- Center for Neuromuscular Diseases, Child Neurology and Psychiatry Unit, Regina Margherita Children Hospital, and Department of Neurosciences, University of Torino, 10124 Torino, Italy
| | - Tiziana Mongini
- Center for Neuromuscular Diseases, Child Neurology and Psychiatry Unit, Regina Margherita Children Hospital, and Department of Neurosciences, University of Torino, 10124 Torino, Italy
| | - Chiara Fiorillo
- Molecular Medicine, IRCCS Fondazione Stella Maris, Calambrone, 56018 Pisa, Italy
| | - Guja Astrea
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Calambrone, 56018 Pisa, Italy
| | | | - Niculina Butoianu
- Alexandru Obregia Clinical Hospital, sos Berceni 10-12, 041914 Bucharest, Romania
| | - Carmen Sandu
- Alexandru Obregia Clinical Hospital, sos Berceni 10-12, 041914 Bucharest, Romania
| | - Laurent Servais
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center of Research in Myology, Myology Institute, 75013 Paris, France
| | - Gisèle Bonne
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center of Research in Myology, Myology Institute, 75013 Paris, France
| | - Isabelle Nelson
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center of Research in Myology, Myology Institute, 75013 Paris, France
| | - Isabelle Desguerre
- Centre de Référence des Maladies Neuromusculaires de l'Ouest Parisien, Hôpital Necker-Enfants Malades, 75743 Paris, France
| | - Marie-Christine Nougues
- Neuropédiatrie et Unité d'électrophysiologie clinique, Centre de Référence des Maladies Neuromusculaires de l'EST parisien et DHU I2B, Hôpital d'Enfants Armand Trousseau, 75012 Paris, France
| | - Benoit Bœuf
- Service de réanimation néonatale et pédiatrique Hôpital Estaing CHU de Clermont Ferrand, 63000 Clermont-Ferrand, France
| | - Norma Romero
- Unité de pathologies neuromusculaires, Institut de Myologie, Sorbonne Universités, UPMC Université Paris 06 UMRS 974, Inserm U974, CNRS UMR 7215, 75013 Paris, France
| | - Jocelyn Laporte
- Departement Médecine Translationnelle et Neurogénétique, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR 7104, Inserm U 964, 67404 Illkirch, France; Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, 67000 Strasbourg, France
| | - Anne Boland
- Centre National de Génotypage (CNG), 91057 Evry, France
| | - Doris Lechner
- Centre National de Génotypage (CNG), 91057 Evry, France
| | | | - Bertrand Fontaine
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, 75013 Paris, France; AP-HP, Hôpital Pitié-Salpêtrière, 75013 Paris, France
| | - Laure Strochlic
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, 75013 Paris, France
| | - Hanns Lochmuller
- The John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Bruno Eymard
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, 75013 Paris, France; AP-HP, Hôpital Pitié-Salpêtrière, 75013 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center of Research in Myology, Myology Institute, 75013 Paris, France
| | - Michèle Mayer
- Neuropédiatrie et Unité d'électrophysiologie clinique, Centre de Référence des Maladies Neuromusculaires de l'EST parisien et DHU I2B, Hôpital d'Enfants Armand Trousseau, 75012 Paris, France
| | - Sophie Nicole
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, 75013 Paris, France.
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Dettmer J, Ursache R, Campilho A, Miyashima S, Belevich I, O'Regan S, Mullendore DL, Yadav SR, Lanz C, Beverina L, Papagni A, Schneeberger K, Weigel D, Stierhof YD, Moritz T, Knoblauch M, Jokitalo E, Helariutta Y. CHOLINE TRANSPORTER-LIKE1 is required for sieve plate development to mediate long-distance cell-to-cell communication. Nat Commun 2014; 5:4276. [PMID: 25008948 DOI: 10.1038/ncomms5276] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Accepted: 06/02/2014] [Indexed: 11/09/2022] Open
Abstract
Phloem, a plant tissue responsible for long-distance molecular transport, harbours specific junctions, sieve areas, between the conducting cells. To date, little is known about the molecular framework related to the biogenesis of these sieve areas. Here we identify mutations at the CHER1/AtCTL1 locus of Arabidopsis thaliana. The mutations cause several phenotypic abnormalities, including reduced pore density and altered pore structure in the sieve areas associated with impaired phloem function. CHER1 encodes a member of a poorly characterized choline transporter-like protein family in plants and animals. We show that CHER1 facilitates choline transport, localizes to the trans-Golgi network, and during cytokinesis is associated with the phragmoplast. Consistent with its function in the elaboration of the sieve areas, CHER1 has a sustained, polar localization in the forming sieve plates. Our results indicate that the regulation of choline levels is crucial for phloem development and conductivity in plants.
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Affiliation(s)
- Jan Dettmer
- 1] Cell Biology Division, Department of Biology, University of Erlangen-Nuremberg, 91058 Erlangen, Germany [2]
| | - Robertas Ursache
- 1] Institute of Biotechnology, Department of Biological and Environmental Sciences, University of Helsinki, Helsinki FIN-00014, Finland [2]
| | - Ana Campilho
- 1] Institute for Molecular and Cell Biology (IBMC), University of Porto, Porto 4150-180, Portugal [2]
| | - Shunsuke Miyashima
- Institute of Biotechnology, Department of Biological and Environmental Sciences, University of Helsinki, Helsinki FIN-00014, Finland
| | - Ilya Belevich
- Institute of Biotechnology, Department of Biological and Environmental Sciences, University of Helsinki, Helsinki FIN-00014, Finland
| | - Seana O'Regan
- Neurophotonics Laboratory, CNRS/Université Paris Descartes, 45, rue des Saints-Pères, 75270 Paris, France
| | - Daniel Leroy Mullendore
- School of Biological Sciences, Washington State University, Pullman, Washington 99164-4236, USA
| | - Shri Ram Yadav
- Institute of Biotechnology, Department of Biological and Environmental Sciences, University of Helsinki, Helsinki FIN-00014, Finland
| | - Christa Lanz
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany
| | - Luca Beverina
- Department of Materials Science, University of Milano-Bicocca, Via R. Cozzi 55, 20125 Milano, Italy
| | - Antonio Papagni
- Department of Materials Science, University of Milano-Bicocca, Via R. Cozzi 55, 20125 Milano, Italy
| | - Korbinian Schneeberger
- Max Planck Institute for Plant Breeding Research, Department for Plant Developmental Biology, 50829 Cologne, Germany
| | - Detlef Weigel
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany
| | - York-Dieter Stierhof
- ZMBP, Mikroskopie, Universität Tübingen, Auf der Morgenstelle 5, 72076 Tübingen, Germany
| | - Thomas Moritz
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Center, Swedish University of Agricultural Sciences, SE-90183 Umeå, Sweden
| | - Michael Knoblauch
- School of Biological Sciences, Washington State University, Pullman, Washington 99164-4236, USA
| | - Eija Jokitalo
- Institute of Biotechnology, Department of Biological and Environmental Sciences, University of Helsinki, Helsinki FIN-00014, Finland
| | - Ykä Helariutta
- Institute of Biotechnology, Department of Biological and Environmental Sciences, University of Helsinki, Helsinki FIN-00014, Finland
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Machová E, O'Regan S, Newcombe J, Meunier FM, Prentice J, Dove R, Lisá V, Dolezal V. Detection of choline transporter-like 1 protein CTL1 in neuroblastoma x glioma cells and in the CNS, and its role in choline uptake. J Neurochem 2009; 110:1297-309. [PMID: 19519661 DOI: 10.1111/j.1471-4159.2009.06218.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Choline is an essential nutrient necessary for synthesis of membrane phospholipids, cell signalling molecules and acetylcholine. The aim of this study was to detect and characterize the choline transporter-like 1 (CTL1/SLC44A1) protein in CNS tissues and the hybrid neuroblastoma x glioma cell line NG108-15, which synthesizes acetylcholine and has high affinity choline transport but does not express the cholinergic high affinity choline transporter 1. The presence of CTL1 protein in NG108-15 cells was confirmed using our antibody G103 which recognizes the C-terminal domain of human CTL1. Three different cognate small interfering RNAs were used to decrease CTL1 mRNA in NG108-15 cells, causing lowered CTL1 protein expression, choline uptake and cell growth. None of the small interfering RNAs influenced carnitine transport, demonstrating the absence of major non-specific effects. In parental C6 cells knockdown of CTL1 also reduced high affinity choline transport. Our results support the concept that CTL1 protein is necessary for the high affinity choline transport which supplies choline for cell growth. The presence of CTL1 protein in rat and human CNS regions, where it is found in neuronal, glial and endothelial cells, suggests that malfunction of this transporter could have important implications in nervous system development and repair following injury, and in neurodegenerative diseases.
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Affiliation(s)
- Eva Machová
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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Lane-Guermonprez L, Morot-Gaudry-Talarmain Y, Meunier FM, O'Regan S, Onofri F, Le Caer JP, Benfenati F. Synapsin associates with cyclophilin B in an ATP- and cyclosporin A-dependent manner. J Neurochem 2005; 93:1401-11. [PMID: 15935056 DOI: 10.1111/j.1471-4159.2005.03125.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [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: 11/30/2022]
Abstract
Immunophilins are ubiquitous enzymes responsible for proline isomerisation during protein synthesis and for the chaperoning of several membrane proteins. These activities can be blocked by the immunosuppressants cyclosporin A, FK506 and rapamycin. It has been shown that all three immunosuppressants have neurotrophic activity and can modulate neurotransmitter release, but the molecular basis of these effects is currently unknown. Here, we show that synapsin I, a synaptic vesicle-associated protein, can be purified from Torpedo cholinergic synaptosomes through its affinity to cyclophilin B, an immunophilin that is particularly abundant in brain. The interaction is direct and conserved in mammals, and shows a dissociation constant of about 0.5 microM in vitro. The binding between the two proteins can be disrupted by cyclosporin A and inhibited by physiological concentrations of ATP. Furthermore, cyclophilin B co-localizes with synapsin I in rat synaptic vesicle fractions and its levels in synaptic vesicle-containing fractions are decreased in synapsin knockout mice. These results suggest that immunophilins are involved in the complex protein networks operating at the presynaptic level and implicate the interaction between cyclophilin B and synapsins in presynaptic function.
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Affiliation(s)
- Lydie Lane-Guermonprez
- Laboratoire de Neurobiologie Cellulaire et Moléculaire, CNRS UPR 9040, Gif sur Yvette Cedex, France
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Abstract
We show here that the choline transporter-like (CTL) family is more extensive than initially described with five genes in humans and complex alternative splicing. In adult rat tissues, CTL2-4 mRNAs are mainly detected in peripheral tissues, while CTL1 is widely expressed throughout the nervous system. During rat post-natal development, CTL1 is expressed in several subpopulations of neurones and in the white matter, where its spatio-temporal distribution profile recalls that of myelin basic protein, an oligodendrocyte marker. We identified two major rat splice variants of CTL1 (CTL1a and CTL1b) differing in their carboxy-terminal tails with both able to increase choline transport after transfection in neuroblastoma cells. In the developing brain, CTL1a is expressed in both neurones and oligodendroglial cells, whereas CTL1b is restricted to oligodendroglial cells. These findings suggest specific roles for CTL1 splice variants in both neuronal and oligodendrocyte physiology.
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Affiliation(s)
- E Traiffort
- Institut de Neurobiologie Alfred Fessard IFR 2118 CNRS, Laboratoire de Neurobiologie Cellulaire et Moléculaire, UPR 9040, Gif-sur-Yvette, France.
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Abstract
For decades, the connection between cell size and division has been the subject of controversy. While in yeast, cell size checkpoints coordinate cellular growth with cell-cycle progression, it has been recently shown that large and small Schwann cells proliferate at the same rate (Conlon and Raff, 2003, J Biol 2:7). From this point of view, it is important to know whether normal and tumoral cells are similar. During continuous culture of NG108-15 neuroblastoma x glioma cells, the rate of proliferation, cell size, and external pH changed in parallel. At constant pH, the cell size-proliferation relationship followed a bell-shaped curve, so that proliferation was optimal within a cell volume window. In contrast, external acidification decreased proliferation independently of cell size. Using electrophysiological techniques, we showed that changes in cell size were dependent on both the uptake of nutrients and the passive influx of ions. Furthermore, an increase in cell size was associated with an increase in total proteins/cell. Another way to influence cell growth and proliferation is to alter the activity of the PI-3 kinase and target of rapamycin (TOR) signaling pathway. In NG108-15 cells, pharmacological inhibition of these proteins with LY 294002 and rapamycin respectively decreased proliferation but did not modify cell size. In contrast, aphidicolin treated cells did not proliferate, but they continued to increase in size. Altogether these results indicate that the proliferation of NG108-15 cells is controlled by both cell size-dependent and independent mechanisms that include extracellular pH and PI-3 kinase activity.
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Abstract
The presumptive choline transporter, CTL1, was initially identified through functional complementation of a triple yeast mutant (ctr ise URA3delta) with deficiencies in both choline transport and choline neosynthesis under selective conditions that cause perturbations in membrane synthesis and growth. After transformation of these yeasts with a heterologous yeast expression library made from Torpedo electric lobe cDNAs, several colonies showed increased growth but only one clone increased the accumulation of external choline. The corresponding full-length cDNA was isolated and encodes a protein with 10 transmembrane domains. Northern analysis of Torpedo mRNA indicates that CTL1 is expressed at high levels in the spinal cord and brain. In Xenopus oocytes, Torpedo CTL1 expression was associated with the appearance of sodium independent high-affinity choline uptake. We propose that CTL1 plays a role in providing choline for membrane synthesis in the nervous system.
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Affiliation(s)
- Seana O'Regan
- Laboratoire de Neurobiologie Cellulaire et Moléculaire, CNRS, 91198 Gif-sur-Yvette, France.
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8
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Abstract
We initially isolated CTL1 from the electric lobe of brain through functional complementation of a yeast mutant deficient in choline transport. Here, we present the first characterization of an antibody to the C-terminal of CTL1. When full length torpedo CTL1 was expressed in oocytes, a broad 60 kDa band appeared concomitant with the detection of immunoreactivity at the plasma membrane. In, the native protein was prominent throughout the CNS and along the electric nerves. CTL1 immunolabeling was particularly conspicuous in the myelin sheath surrounding the electric nerve and in central myelinated structures. The association of the presumptive choline transporter, CTL1, with myelin membranes suggests a role for this new protein in lipid production.
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Affiliation(s)
- François-Marie Meunier
- Laboratoire de Neurobiologie Cellulaire et Moléculaire, CNRS, 91198 Gif-sur-Yvette, France
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9
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Abstract
The immunosuppressor cyclosporin A inhibits the peptidyl-prolyl-cis/trans-isomerase activity of cyclophilins and the resulting complex inhibits the phosphatase activity of calcineurin. Both enzymes were detected in peripheral nerve endings isolated from the electric organ of Torpedo and shown to be affected by 10 micro m cyclosporin A. Among the cholinergic properties studied, choline uptake was specifically inhibited by cyclosporin A to a maximum of 40%. Cyclosporin A decreased the rate of choline transport but not the binding of the non-transportable choline analogue hemicholinium-3, indicating that the number of membrane transporters was not affected. Through the use of two other immunosuppressors, FK506, which also inhibits calcineurin, and rapamycin, which does not, two different mechanisms of choline uptake inhibition were uncovered. FK506 inhibited the rate of choline transport, whereas rapamycin diminished the affinity for choline. The Torpedo homologue of the high affinity choline transporter CHT1 was cloned and its activity was reconstituted in Xenopus oocytes. Choline uptake by oocytes expressing tCHT1 was inhibited by all three immunosuppressors and also by microinjection of the specific calcineurin autoinhibitory domain A457-481, indicating that the phosphatase calcineurin regulates CHT1 activity and could be the common target of cyclosporin and FK506. Rapamycin, which changed the affinity of the transporter, may have acted through an immunophilin on the isomerization of critical prolines that are found in the tCHT1 sequence.
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Affiliation(s)
- Lydie Guermonprez
- Laboratoire de Neurobiologie Cellulaire et Moléculaire, Gif-sur-Yvette, France.
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Abstract
Saccharomyces cerevisiae strains lacking a functional Pho85 cyclin-dependent kinase (cdk) exhibit a complex phenotype, including deregulation of phosphatase genes controlled by the transcription factor Pho4, slow growth on rich media, failure to grow using galactose, lactate or glycerol as a carbon source and hyperaccumulation of glycogen. The ability of Pho85 to regulate the transcription factor Pho4 is mediated by its association the Pho80 cyclin. Some other regulatory functions of the Pho85 cdk have been shown to be mediated via its interaction with a recently identified family of Pho80-related cyclins (Pcls). Here, we show that the poorly characterized Pho80-like protein Pcl7 forms a functional kinase complex with the Pho85 cdk, and that the activity of this complex is inhibited in response to phosphate starvation. Additionally, we show that Pcl7 interacts with the phosphate-regulated cyclin-cdk inhibitor Pho81, and that the regulation of the Pcl7-Pho85 complex in response to changes in phosphate levels is dependent on Pho81. Thus, we demonstrate for the first time that the Pho81 regulator is not dedicated to regulating Pho80, but may act to co-ordinate the activity of both the Pho80-Pho85 and Pcl7-Pho85 cyclin-cdk complexes in response to phosphate levels. We also demonstrate that expression of Pcl7 is cell cycle regulated, with maximal activity occurring in mid to late S-phase, perhaps suggesting a role for Pcl7 in cell cycle progression. Finally, we describe the phenotype of pcl7Delta and pcl6Delta yeast strains that have defects in carbon source utilization.
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Affiliation(s)
- M Lee
- Eukaryotic Transcription Laboratory, Marie Curie Research Institute, The Chart, Oxted, Surrey RH8 OTL, UK
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O'Regan S, Traiffort E, Ruat M, Cha N, Compaore D, Meunier FM. An electric lobe suppressor for a yeast choline transport mutation belongs to a new family of transporter-like proteins. Proc Natl Acad Sci U S A 2000; 97:1835-40. [PMID: 10677542 PMCID: PMC26522 DOI: 10.1073/pnas.030339697] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.1] [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: 11/18/2022] Open
Abstract
Choline is an important metabolite in all cells due to the major contribution of phosphatidylcholine to the production of membranes, but it takes on an added role in cholinergic neurons where it participates in the synthesis of the neurotransmitter acetylcholine. We have cloned a suppressor for a yeast choline transport mutation from a Torpedo electric lobe yeast expression library by functional complementation. The full-length clone encodes a protein with 10 putative transmembrane domains, two of which contain transporter-like motifs, and whose expression increased high-affinity choline uptake in mutant yeast. The gene was called CTL1 for its choline transporter-like properties. The homologous rat gene, rCTL1, was isolated and found to be highly expressed as a 3. 5-kb transcript in the spinal cord and brain and as a 5-kb transcript in the colon. In situ hybridization showed strong expression of rCTL1 in motor neurons and oligodendrocytes and to a lesser extent in various neuronal populations throughout the rat brain. High levels of rCTL1 were also identified in the mucosal cell layer of the colon. Although the sequence of the CTL1 gene shows clear homology with a single gene in Caenorhabditis elegans, several homologous genes are found in mammals (CTL2-4). These results establish a new family of genes for transporter-like proteins in eukaryotes and suggest that one of its members, CTL1, is involved in supplying choline to certain cell types, including a specific subset of cholinergic neurons.
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Affiliation(s)
- S O'Regan
- Biologie de la Neurotransmission and Junior group ATIPE, Laboratoire de Neurobiologie Cellulaire et Moléculaire (Unité 9040), Centre National de la Recherche Scientifique, 1 avenue de la Terrasse, 91198, Gif-sur-Yvette, France.
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12
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O'Regan S, Birman S, Meunier FM. Regulation of hemicholinium-3 sensitive choline uptake in Xenopus laevis oocytes by the second C2 domain of synaptotagmin. Brain Res Mol Brain Res 1995; 32:135-42. [PMID: 7494451 DOI: 10.1016/0169-328x(95)00071-y] [Citation(s) in RCA: 4] [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] [Indexed: 01/25/2023]
Abstract
A size-fractionated torpedo electric lobe cDNA library was screened for the neuronal choline transporter by functional expression in oocytes. A clone, TLC2B, was isolated that induced a component of choline uptake that was hemicholinium-3 sensitive and inhibited by the substitution of lithium for sodium at low choline concentrations. However, [3H]choline uptake by both injected and non-injected oocytes were characterized by high affinity constants, suggesting that TLC2B could be affecting a native choline transporter. Indeed, hemicholinium-3 sensitive choline uptake could also be induced by preincubation of non-injected oocytes with a protein kinase C inhibitor, H-7. By sequence analysis and immuno-precipitation, the peptide produced by injection of TLC2B cRNA was identified as a soluble 24 kDa C-terminal fragment of the neuronal protein, synaptotagmin. Full length synaptotagmin was, however, ineffective in the functional test. The peptide encoded by TLC2B corresponds to the second protein kinase C-homologous domain of torpedo synaptotagmin, and like other soluble C2 domain peptides, was capable of calcium-dependent translocation to membranes. Its action on choline uptake in oocytes was, however, abolished by the addition of calcium in the presence of a calcium ionophore. These results suggest that the interaction of certain C2 domains, such as the C-terminal domain of synaptotagmin, with more specific targets may be anulled in the presence of calcium due to its absorption to membrane phospholipids.
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Affiliation(s)
- S O'Regan
- Département de Neurochimie, CNRS, Gif-sur-Yvette, France
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13
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Abstract
The Ewing's sarcoma cell line ICB 112 was examined in detail for a cholinergic phenotype. Choline acetyltransferase activity (12.3 +/- 2.9 nmol/h/mg of protein) was associated with the presence of multiple mRNA species labeled with a human choline acetyltransferase riboprobe. Choline was taken up by the cells by a high-affinity, hemicholinium-3-sensitive transporter that was partially inhibited when lithium replaced sodium in the incubation medium; the choline taken up was quickly incorporated into both acetylcholine and phosphorylcholine. High-affinity binding sites for vesamicol, an inhibitor of vesicular acetylcholine transport, were also present. The mRNAs for synaptotagmin (p65) and the 15-kDa proteolipid were readily detected and were identical in size to those observed in cholinergic regions of the human brain. Cumulative acetylcholine efflux was increased by raising the extracellular potassium level or the addition of a calcium ionophore, but the time course of stimulated efflux was slow and persistent. These results show that this morphologically undifferentiated cell line is capable of acetylcholine synthesis and expresses markers for synaptic vesicles as well as proteins implicated in calcium-dependent release but lacks an organized release mechanism.
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Affiliation(s)
- S O'Regan
- Département de Neurochimie, CNRS, Gif-sur-Yvette, France
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14
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Patriquin HB, Lafortune M, Jéquier JC, O'Regan S, Garel L, Landriault J, Fontaine A, Filiatrault D. Stenosis of the renal artery: assessment of slowed systole in the downstream circulation with Doppler sonography. Radiology 1992; 184:479-85. [PMID: 1620852 DOI: 10.1148/radiology.184.2.1620852] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.4] [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: 12/27/2022]
Abstract
Slowing and dampening of systole in the arterial network distal to stenosis is a well-known Doppler sign of severe arterial stenosis. To determine whether this sign is present in boys and girls with such stenosis, intrarenal Doppler curves (acceleration index [AI] and resistive index [RI]) were compared with findings on renal arteriograms in 20 boys and girls; the AI was also measured in 10 boys and girls without renal disease. Statistical analysis of AI and RI measurements was performed. Eleven of 32 renal arteries were normal. The normal AI was 4.0-7.0; in arteries with greater than 75% stenosis, the AI was 0.7-1.7. In five arteries studied after angioplasty, the AI had changed from 0.7-1.5 to 4.0-5.6 at the first posttreatment examination (performed 28 hours to 1 week after angioplasty), and it remained normal during the 3-year follow-up period. In kidneys with stenotic arteries, the RIs were lower (0.43-0.54) than in healthy subjects (0.56-0.63). Regression and correlation coefficients of AI and RI measurements were statistically significant, and discrimination between normal arteries and those with greater than 75% stenosis was excellent.
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Affiliation(s)
- H B Patriquin
- Department of Radiology, Hôpital Sainte-Justine, Montreal, Quebec, Canada
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15
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O'Regan S. Rural radiography--the facts. Qld Nurse 1991; 10:18-20. [PMID: 1796176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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16
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Paradis K, O'Regan S, Seidman E, Laberge JM, Dupuis C, Gaudreault P, Rasquin-Weber A. Improvement in true glomerular filtration rate after cyclosporine fractionation in pediatric liver transplant recipients. Transplantation 1991; 51:922-5. [PMID: 2014557] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- K Paradis
- Division of Gastroenterology and Nutrition, Hôpital Ste-Justine, Université de Montréal, Canada
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17
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Abstract
Serum and red cell folate concentrations were estimated in 68 affective disorder patients taking lithium prophylactically, 65 of whom had bipolar disorder. The number of hospital admissions, the frequency of use of additional mood altering treatments and the Affective Morbidity Index were calculated for the 2 years of the study. Contrary to other findings, there were no differences between the folate concentrations for different severities of affective morbidity. These results question the rationale of prescribing folic acid preparations for lithium-treated bipolar disorder patients, but the authors indicate that folate concentrations may be low in lithium-treated unipolar depressives.
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Affiliation(s)
- P McKeon
- Depression Research Unit, St. Patrick's Hospital, Dublin, Ireland
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18
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Richler M, Milot J, Quigley M, O'Regan S. Ocular manifestations of nephropathic cystinosis. The French-Canadian experience in a genetically homogeneous population. Arch Ophthalmol 1991; 109:359-62. [PMID: 2003795 DOI: 10.1001/archopht.1991.01080030061039] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A large spectrum of ocular pathologic features have been described in infantile cystinosis. Reported symptoms may require corneal transplantation and therapeutic efforts to solubilize cystine crystals with hourly administration of cysteamine (mercaptamine) drops. French Canada has the highest incidence of cystinosis in the world. We studied 18 patients with cystinosis who appeared to have much milder ocular involvement than that in other reported series. No operative interventions were required. Relatively mild photophobia was the most common ocular manifestation of cystinosis.
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Affiliation(s)
- M Richler
- Department of Ophthalmology, Hôpital Saint-Justine, Montreal, Quebec, Canada
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19
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Fournier C, Milot JA, Clermont MJ, O'Regan S. The concept of corticosteroid cataractogenic factor revisited. Can J Ophthalmol 1990; 25:345-7. [PMID: 2090339] [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: 12/30/2022]
Abstract
Formation of posterior subcapsular cataracts is a known complication of systemic corticosteroid therapy. However, the relation between steroid dosage, cumulative dose and type of steroid on one hand and the subsequent formation of cataract on the other is unclear. We carried out a study to determine the incidence of posterior subcapsular cataracts in 64 children who had undergone renal transplantation and to attempt to determine what factors were associated with cataract formation. Cataracts were detected in 17 (26%) of the patients. The steroid dosage, cumulative dose and duration of therapy were not associated with cataract formation. There was a significant difference in the distribution of HLA-CW3 antigen between the patients with cataracts and those without cataracts. The reason for the link between corticosteroid therapy and formation of posterior subcapsular cataracts remains unclear.
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Affiliation(s)
- C Fournier
- Department of Ophthalmology, Hôpital Sainte-Justine, Montreal, PQ
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20
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Abstract
Hemolytic-uremic syndrome (HUS) of childhood is a triad of acute hemolytic anemia, thrombocytopenia, and acute renal failure associated with a gastrointestinal prodrome. From 1977 to 1988, 134 patients with HUS were admitted to this institution. All patients presented with abdominal pain and diarrhea, which was virtually always bloody. Seventy-eight patients (60%) required dialysis. Five patients died (4%). One patient died as a result of colon perforation, the other four patients died of other nonsurgical complications of HUS. Three patients underwent exploratory laparotomy. One patient had a hemoperitoneum from mesenteric and transmural bleeding of the entire intraabdominal colon. Another patient had undergone surgery elsewhere for presumed intussusception with pancolitis found at exploration. Fourteen days postoperatively, he had a spontaneous perforation of the transverse colon. The third patient presented with pancolitis and perforation of the transverse colon. Despite surgical intervention he died on the sixth postoperative day. One other patient was treated conservatively for pancreatitis, which developed 3 weeks after her presentation with HUS. Complications requiring surgical intervention in HUS are rare, potentially lethal, and usually involve the colon.
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Affiliation(s)
- M L Brandt
- Department of Surgery, Hôpital Ste-Justine, Montreal, Quebec, Canada
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21
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Russo P, O'Regan S. Visceral pathology of hereditary tyrosinemia type I. Am J Hum Genet 1990; 47:317-24. [PMID: 2378357 PMCID: PMC1683701] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The major pathological findings in 23 patients with hereditary tyrosinemia type I seen at the Hôpital Sainte-Justine over a 23-year period are reviewed in combination with findings in the literature. Hepatic and renal alterations are given special emphasis. Hepatic changes differ in the acute and chronic forms of the disease. The former is characterized by alterations shared by several hepatopathies of infancy, whereas the latter is characterized by established cirrhosis, frequently of a mixed macro- and micronodular type, with a frightening propensity for the development of hepatocellular carcinoma. Renal changes reflect tubular injury, resulting in Fanconi syndrome, with tubular dilatation, nephrocalcinosis, and involution of epithelial cells. A significant proportion of patients also reveal some degree of glomerulosclerosis and interstitial fibrosis, indicating at least the need for careful assessment and follow-up of renal function, particularly in light of the adverse renal effects of immunosuppressive regimens used in liver transplantation.
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Affiliation(s)
- P Russo
- Department of Pathology, Hôpital Sainte-Justine, Montréal, Quebec, Canada
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22
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Rousseau E, Blais N, O'Regan S. Decreased necessity for dialysis with loop diuretic therapy in hemolytic uremic syndrome. Clin Nephrol 1990; 34:22-5. [PMID: 2387099] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
High dose loop diuretic therapy was administered at time of admission to hospital or at time of diagnosis to 54 patients with childhood hemolytic uremic syndrome. Forty-one patients maintained a diuresis sufficient to avoid the necessity for dialysis. When compared to an earlier time period the dialysis rate fell from 82% to 24% with furosemide therapy. Though a change in disease severity may explain the decrease in necessity for dialysis, a salutary effect of furosemide therapy may also be responsible.
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Affiliation(s)
- E Rousseau
- Department of Pediatrics, University of Montreal, Hôpital Ste-Justine, Quebec, Canada
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23
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O'Regan S, Blais N, Russo P, Pison CF, Rousseau E. Hemolytic uremic syndrome: glomerular filtration rate, 6 to 11 years later measured by 99mTc DTPA plasma slope clearance. Clin Nephrol 1989; 32:217-20. [PMID: 2684458] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Thirty-seven patients who had been discharged from hospital six to eleven years after an acute episode of hemolytic uremic syndrome were studied. Glomerular filtration rates were measured by plasma slope clearance using 99mTc DTPA. Eleven patients had GFRs below 60 ml/min/1.73 m2. Hemolytic uremic syndrome may result in an appreciable deterioration in GFR undectable by routine laboratory tests and without clinical signs.
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Affiliation(s)
- S O'Regan
- Department of Pediatrics, Hôpital Ste-Justine, Montreal, Quebec, Canada
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24
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Abstract
Seventeen children with acute renal failure due to the hemolytic-uremic syndrome were examined with duplex Doppler ultrasound. Serial measurements of intrarenal arterial pulsatility were obtained by means of the Pourcelot index. These were compared with daily urine volume, both during the phase of renal failure (during which most of the children were undergoing peritoneal dialysis) and during recovery of renal function. During oliguria or anuria there was either no intrarenal arterial flow (ie, absent Doppler shifts), or absent, reversed, or markedly reduced diastolic flow. Within 24-48 hours after diastolic Doppler shifts returned to normal, diuresis occurred. The Doppler examination enabled prediction of recovery and allowed dialysis treatment to be abbreviated or, in some cases, canceled.
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Affiliation(s)
- H B Patriquin
- Department of Radiology Hôpital Sainte-Justine, Montreal, Que, Canada
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25
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Gaudry-Talarmain YM, Diebler MF, O'Regan S. Compared effects of two vesicular acetylcholine uptake blockers, AH5183 and cetiedil, on cholinergic functions in Torpedo synaptosomes: acetylcholine synthesis, choline transport, vesicular uptake, and evoked acetylcholine release. J Neurochem 1989; 52:822-9. [PMID: 2493069 DOI: 10.1111/j.1471-4159.1989.tb02527.x] [Citation(s) in RCA: 20] [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: 01/01/2023]
Abstract
We examined the effects of two drugs, AH5183 and cetiedil, demonstrated to be potent inhibitors of acetylcholine (ACh) transport by isolated synaptic vesicles on cholinergic functions in Torpedo synaptosomes. AH5183 exhibited a high specificity toward vesicular ACh transport, whereas cetiedil was shown to inhibit both high-affinity choline uptake and vesicular ACh transport. Choline acetyltransferase was not affected by either drug. High external choline concentrations permitted us to overcome cetiedil inhibition of high-affinity choline transport, and thus synthesis of [14C]ACh in treated preparations was similar to that in controls. We then tested evoked ACh release in drug-treated synaptosomes under conditions where ACh translocation into the vesicles was blocked. We observed that ACh release was impaired only in cetiedil-treated preparations; synaptosomes treated with AH5183 behaved like the controls. Thus, this comparative study on isolated nerve endings allowed us to dissociate two steps in drug action: upstream, where both AH5183 and cetiedil are efficient blockers of the vesicular ACh translocation, and downstream, where only cetiedil is able to block the ACh release process.
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26
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Abstract
Two children had polytetrafluoroethylene (PTFE) arteriovenous thigh grafts for hemodialysis access. In one patient, after renal transplantation, a steal syndrome, which prevented renal graft function, developed. The renal transplant functioned promptly when the vascular graft was ligated. In the second case, acute thrombosis of the PTFE graft resulted in transient hypertensive encephalopathy. PTFE thigh grafts, because of the diversion of a large percentage of cardiac output through them, may have dramatic and dangerous consequences in transplanted children.
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Affiliation(s)
- S O'Regan
- Department of Nephrology, University of Montreal, Hôpital Sainte-Justine, Que., Canada
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27
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Robitaille P, O'Regan S, Mongeau JG, Clermont MJ, Bensoussan A, Yazbeck S. [Continuous peritoneal dialysis in children]. Union Med Can 1989; 118:12-7. [PMID: 2711531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Thirty-two uremic children were treated by chronic peritoneal dialysis (CPD) since February 1982. Fifteen chose chronic ambulatory peritoneal dialysis (CCPD) while the 17 others were treated by continuous cycle peritoneal dialysis (CCPD). To this day, 10 patients (31%) are alive with a functioning kidney transplant, 16 (50%) are still treated by CPD awaiting a transplant, 5 have died (16%) and one went back to hemodialysis (3%). Complication in ranking order were peritonitis, mechanical drainage problems of the catheter and hernias. Linear growth was from good to excellent in the majority of patients. Globally, CPD was found to be attractive mainly because it allows a good quality of life.
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28
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Abstract
Sodium-dependent binding of [3H]hemicholinium-3 was observed to be 10-fold higher with presynaptic membranes from the electric organ than with electroplaque membranes and this binding site copurified with synaptosomal membranes. The KD for specific [3H]hemicholinium-3 binding was found to be 31 +/- 4 nM and the Bmax, 5.0 +/- 0.2 pmol/mg protein; a Ki of 16 nM was estimated for hemicholinium-3 as a competitive inhibitor of high-affinity choline transport in electric organ synaptosomes. Choline and choline analogues were equally potent as inhibitors of [3H]choline uptake and [3H]hemicholinium-3 binding. Tubocurarine and oxotremorine also inhibited uptake and binding, but carbachol was without effect in both tests. These findings suggest that [3H]hemicholinium binds to the high-affinity choline transporter present at the cholinergic nerve terminal membrane. A comparison of maximal velocities for choline transport and the maximal number of hemicholinium-3 binding sites indicated that the high-affinity choline transporter has an apparent turnover number of about 3s-1 at 20 degrees C under resting conditions. The high transport rates observed in electric organ synaptosomes are likely due to the high density of high-affinity choline transporters in this tissue, estimated on the basis of [3H]hemicholinium-3 binding to be of the order of 100/micron2 of synaptosomal membrane.
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Affiliation(s)
- S O'Regan
- Département de Neurochimie, Laboratoire de Neurobiologie Cellulaire et Moleculaire-C.N.R.S., Gif sur Yvette, France
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29
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O'Regan S, Rousseau E. Hemolytic uremic syndrome: urate nephropathy superimposed on an acute glomerulopathy? An hypothesis. Clin Nephrol 1988; 30:207-10. [PMID: 3214966] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The oligo-anuria of the hemolytic uremic syndrome is attributed to the presence of a renal lesion which is predominantly glomerulopathic but which may have a vasculopathic component of varying severity. Fourteen children, four of whom had anuric, four oliguric and six non oliguric acute renal failure were treated with intravenous fluids and high dose intravenous furosemide therapy. Polyuria was induced in all, obviating the need for dialysis. We hypothesize that oligo-anuria in this syndrome may be due to the previously recognized hyperuricemia causing a urate nephropathy superimposed on the glomerulopathy thus explaining its possible amenability to fluid and diuretic therapy.
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Affiliation(s)
- S O'Regan
- Department of Pediatrics, University of Montreal, Hôpital Ste-Justine, Quebec, Canada
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30
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Abstract
OBJECTIVE To review the history, basic defect, pathogenesis, clinical manifestations, diagnosis, and treatment of nephropathic cystinosis. DESIGN Lysosomal membrane transport studies, clinical reports, and a historically controlled 7-year trial of oral cysteamine therapy. SETTING University centers in the United States and Canada. PATIENTS One hundred forty-eight children, aged 0 to 12, with nephropathic cystinosis before renal transplant, who had renal tubular Fanconi syndrome, failure to grow, corneal cystine crystals, and elevated leukocyte cystine; 34 patients, aged 9 to 29, after transplant, some with visual impairment, corneal erosions, pancreatic dysfunction, or neurologic deterioration. INTERVENTION Before transplant, replacement of renal losses, and treatment with oral cysteamine (55 mg/kg body weight.d for 1 to 6 years) and topical cysteamine eyedrops (0.1%, 1 drop/h while awake, for 6 months). After transplant, oral cysteamine and symptomatic treatment of late complications. MEASUREMENTS AND MAIN RESULTS Untreated patients reached renal failure at age 10. Oral cysteamine lowered leukocyte cystine over 80%, and in patients before transplant, improved growth and preserved renal function (mean creatinine clearance [+/- SE], 0.64 +/- 0.04 mL/s.1.73 m2 [38.5 +/- 2.5 mL/min.1.73 m2] in the cysteamine group compared with 0.50 +/- 0.03 mL/s.1.73 m2 [29.7 +/- 2.0 mL/min.1.73 m2] in controls; 95% CI for the difference, 1.8 to 15.8). Cysteamine eyedrops cleared the corneal crystals of two children less than 2 years old. CONCLUSIONS Cystinosis is a lysosomal storage disease due to impaired transport of cystine out of lysosomes. In young children, growth can be improved and renal deterioration delayed or prevented by oral cysteamine. Nonrenal complications after transplant might be prevented with long-term oral cysteamine.
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31
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O'Regan S, Garel L, Robitaille P, Yazbeck S. Post-rejection ureteral obstruction owing to ureteral adherence to graft inferior pole. J Urol 1988; 139:560-1. [PMID: 3278134 DOI: 10.1016/s0022-5347(17)42523-7] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We describe 2 renal transplant patients with increasing plasma creatinine levels after resolution of acute rejection episodes. Antegrade pyelography demonstrated adherence of the ureter to the inferior pole of the kidney with partial obstruction in both cases, which was confirmed at operation.
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Affiliation(s)
- S O'Regan
- Department of Pediatrics, Hôpital Sainte-Justine, Montreal, Quebec, Canada
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32
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Kaplan BS, Kaplan P, de Chadarevian JP, Jequier S, O'Regan S, Russo P. Variable expression of autosomal recessive polycystic kidney disease and congenital hepatic fibrosis within a family. Am J Med Genet 1988; 29:639-47. [PMID: 3377007 DOI: 10.1002/ajmg.1320290323] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Blyth and Ockenden [1971] assigned patients with autosomal recessive polycystic kidney disease (ARPCKD) to 4 discrete groups (perinatal, neonatal, infantile, juvenile) on the basis of the age of presentation. They and others speculated that at least 4 genes were responsible for what they considered to be closely related, but different conditions. These views have gained wide but not universal acceptance. Some workers have insisted that the perinatal and neonatal "forms" of ARPCKD differ fundamentally from the juvenile "form." However, others have proposed that ARPCKD-CHF (congenital hepatic fibrosis) and CHF-ARPCKD are manifestations of the same disease with variation of expression in a kindred. We report on a patient who presented at birth (1979) with ARPCKD and respiratory distress. He died at 18 hr. An older sib presented at 16 yr in 1984. She had no symptoms, but her mother wanted reassurance that the daughter did not have a condition similar to that of the deceased sib. Blood pressure was 120/80 mm Hg and there was hepatosplenomegaly. A diagnosis of renal tubular ectasia and CHF was made by ultrasonography, radiologic studies, and a liver biopsy. The evidence from families such as this favors the concept that ARPCKD and CHF presenting as Blyth and Ockenden's perinatal form, and CHF and renal tubular ectasia as their juvenile form, are manifestations of the same genetic disorder, and that the different manifestations are more likely variations in expression than the results of different mutant genes. The manifestations in this family add weight to the growing body of evidence that intrafamilial variability may occur, not only in autosomal dominant conditions, but also in autosomal recessive disorders.
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Affiliation(s)
- B S Kaplan
- Department of Pediatrics, Montreal Children's Hospital, Quebec
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33
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Abstract
A low incidence of renal disease was noted in a retrospective analysis of pediatric patients with acquired immunodeficiency syndrome. Episodes of acute renal failure were attributable to dehydration or nephrotoxicity. One patient, however, had nephrosis with focal glomerular sclerosis. Focal sclerosis involving 10% to 20% of glomeruli was evident in autopsy tissue from three patients.
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Affiliation(s)
- E Rousseau
- Department of Pediatrics, Hôpital Sainte-Justine, Montreal, Québec
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34
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Abstract
Nephropathic cystinosis causes renal death by approximately age 10 years. With increased life span due to kidney transplantation, ten to 25 years of cystine accumulation has resulted in pancreatic complications in individuals with cystinosis. We noted severe hyperglycemia in five posttransplant patients, three of whom remained insulin-dependent diabetics several years after transplant. The clinical findings were not consistent with steroid-dependent or insulin-resistant diabetes. Pancreatic cystine deposition was detected histologically and biochemically on post-mortem examination of two other patients. We conclude that hyperglycemia may be anticipated in the immediate posttransplant period in cystinotic patients and that some patients will require insulin therapy years later. The use of cystine-depleting agents should be considered in posttransplant cystinosis as an attempt to prevent potential damage to the pancreas and other organs from cystine deposition.
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35
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Sinnassamy P, O'Regan S. Polycythemia in pediatric renal transplantation. Clin Nephrol 1987; 27:242-4. [PMID: 3297438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Post-transplant polycythemia is not uncommon in adult patients and is usually transient, responding to phlebotomy. Five pediatric patients developed erythrocytosis post-transplantation. Three patients had end-stage renal disease due to cystinosis, one had reflux glomerulopathy and one had focal glomerular sclerosis. The probable causes of the polycythemia were graft arterial stenosis in three patients. In one, polycythemia occurred with nephrosis. Polycythemia with hypertension may indicate the presence of arterial stenosis in children post-transplantation.
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36
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Abstract
Little attention has been afforded the relevance of constipation to urinary symptoms. Problems of definition and measurement have contributed to this problem. A review of the literature suggests that rectal dilatation may influence the function of the urinary tract leading to urinary tract infection and enuresis. Our studies indicate that constipation may, by causing uninhibited bladder contractions, cause urinary tract infection, enuresis and vesicoureteral reflux.
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Affiliation(s)
- S Yazbeck
- Department of Pediatric Nephrology and Surgery, Hôpital Ste-Justine, University of Montreal, Que., Canada
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37
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Abstract
Seventeen children who had vesicoureteral reflux underwent urodynamic and rectal manometric studies. All had uninhibited bladder contractions. All had rectal dilatation confirming the presence of constipation by rectal balloon manometry. The recurrent association of constipation with ureteral reflux suggests the possibility of a nonfortuitous association.
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38
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O'Regan S, Turgeon C. Lack of antiglomerular basement membrane antibody binding to alveolar membranes after hydrocarbon exposure in rats. J Clin Lab Immunol 1986; 20:147-9. [PMID: 3746881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A causal relationship has been proposed for the development of Goodpasture's syndrome and hydrocarbon (gasoline) exposure in man. Infusion of antiglomerular basement membrane antibody into rats subjected to gasoline inhalation did not result in linear binding to alveolar basement membranes suggesting that the endothelial barriers remained intact despite administration of near lethal doses of gasoline.
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Abstract
Constipation was confirmed by history, rectal examination, and rectal manometric studies in 22 of 25 children with enuresis. Treatment of constipation resulted in resolution of enuresis. Uninhibited bladder contractions, observed in enuretic constipated children, were also noted in children with constipation alone, suggesting that constipation is a commonly unrecognized etiologic factor in enuresis.
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40
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Abstract
Constipation is associated with and may be an etiologic factor in recurrent urinary tract infection (UTI) in girls. To determine if an increased incidence of urinary infection occurs in constipating illness, we retrospectively analyzed UTI incidence in 146 patients with Hirschsprung's disease. An increased incidence pre- and postoperatively was noted.
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41
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Sinnassamy P, Yazbeck S, Brochu P, O'Regan S. Renal anomalies and agenesis associated with total intestinal aganglionosis. Int J Pediatr Nephrol 1986; 7:1-2. [PMID: 3957555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Four patients with total aganglionosis of the intestine had renal abnormalities. Two patients had cortical subcapsular cysts, one had unilateral renal agenesis and one other had unilateral renal dysplasia. The consistency of renal anomalies with total aganglionosis suggests the presence of a common genetic origin.
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42
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Abstract
We report 2 cases of cadaveric renal transplantation in which the grafts were placed in the right iliac fossa. Postoperatively, both patients complained of ipsilateral thigh weakness. Electromyography and nerve conduction studies indicated femoral nerve neuropathy. Muscle weakness gradually resolved. Difficulty was encountered in placing both grafts, and each kidney and limb were subjected to prolonged ischemia. We suggest that the femoral neuropathy was ischemic in origin.
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43
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Abstract
Medullary sponge kidney is reported in six children aged 2-18 years. One child was asymptomatic; the others had hematuria or a urine-concentrating defect. Renal function and size were otherwise normal, as was liver function. The diagnosis was made at excretory urography according to criteria established in adults. Sonography revealed hyperechogenic pyramids, at first at the periphery, later generalized. Computed tomography proved this to be calcium. Medullary sponge kidney is rare but exists in children. Sonography is very sensitive to the pyramidal nephrocalcinosis that complicates this disease and explains the frequent presenting symptom of hematuria in these children.
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44
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Abstract
The observation that constipation alone may induce uninhibited bladder contractions in children and is associated with recurrent urinary tract infection in childhood suggests an etiologic association. Rectal distension due to faecal retention in chronic functional constipation causes bladder distortion and may cause stimulation of detrusor stretch receptors resulting in detrusor peroneal dyssynergism. Distortion of the trigonal area may result in failure of ureteral valve competence and allow for vesico-ureteric reflux.
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45
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Vyas S, O'Regan S. Reconstitution of carrier-mediated choline transport in proteoliposomes prepared from presynaptic membranes of Torpedo electric organ, and its internal and external ionic requirements. J Membr Biol 1985; 85:111-9. [PMID: 4009695 DOI: 10.1007/bf01871264] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Proteoliposomes made by a butanol-sonication technique from electric organ presynaptic membranes showed choline transport activity. In contrast to intact nerve terminals, the uptake of choline was dissociated from its conversion to acetylcholine in this preparation. The kinetics of choline uptake by proteoliposomes was best described by two Michaelis-Menten components. At a low concentration of choline, uptake was inhibited by hemicholinium-3 and required external Na+ and, thus, closely resembled high-affinity choline uptake by intact cholinergic nerve terminals. Choline transport could be driven by the Na+ gradient and by the transmembrane potential (inside negative) but did not directly require ATP. External Cl-, but not a Cl- gradient, was needed for choline transport activity. It is suggested that internal K+ plays a role in the retention of choline inside the proteoliposome. Proteoliposomes should prove a useful tool for both biochemical and functional studies of the high-affinity choline carrier.
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46
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Abstract
Two children presented with nephrotic syndrome. Renal biopsy demonstrated minimal lesion nephrosis with mesangial IgA deposits. Response to prednisone therapy was prompt in both cases. The clinical and histologic features of these and other reported cases suggested a diagnosis of minimal lesion nephrosis and not IgA nephropathy (Berger's disease).
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47
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Robitaille P, O'Regan S, Mongeau JG, Freeman C, Lortie L, Yazbeck S. Local renal graft irradiation in children. Int J Pediatr Nephrol 1985; 6:133-6. [PMID: 3897089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Between 1974-1979, 64 renal cadaveric transplants were performed in 54 pediatric recipients at our institution. Forty eight of these 64 transplants experienced at least one episode of acute rejection. These patients were divided in two equal groups including 24 transplants in 21 recipients, one group treated with chemical immunosuppression alone, the other group treated by chemical immunosuppression and radiotherapy. Kidney survival at 2 years was 54.1% (13/24) in the control group treated by chemical immunosuppression alone. In the group treated by radiotherapy and immunosuppression, kidney survival after 2 years gave a success rate of 45.8% (11/24). Thus, it would appear that addition of radiotherapy to standard immunosuppressive treatment exerted no beneficial long term effect in acutely rejected renal transplants. In view of the disappointing results obtained with radiotherapy, it is felt that this mode of treatment should be restricted to use in particular circumstances as a temporary means of immunosuppression where systemic immunosuppression is hazardous.
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48
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O'Regan S, Yazbeck S, Schick E. Constipation, bladder instability, urinary tract infection syndrome. Clin Nephrol 1985; 23:152-4. [PMID: 3987104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Forty-seven children with recurrent urinary tract infection were noted to have large fecal reservoirs by rectal examination and rectal manometry. Constipation was accompanied in the majority by enuresis and/or encopresis. Urodynamic studies indicated uninhibited bladder contractions. Aggressive treatment of the constipation resulted in cessation of infection in 44 patients, enuresis in 22 of 32 patients and encopresis in 20 of 21 patients and an improvement in bladder function with cessation of all other forms of treatment.
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49
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Yazbeck S, Danais S, O'Regan S. Nephrosis with varicocele: probable renal vein thrombosis. Eur Urol 1985; 11:215-6. [PMID: 4029240 DOI: 10.1159/000472498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A 3-year-old boy with relapsing nephrosis presented with a left sided varicocele. Echographic studies demonstrated enlargement of the left kidney, and there was delayed excretion on renal scintigraphy suggesting the presence of renal vein thrombosis. The varicocele resolved with remission of his nephrosis.
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50
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Sinnassamy P, O'Regan S. Wegener's granulomatosis in a 7 year old child. Int J Pediatr Nephrol 1984; 5:227-8. [PMID: 6530340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A 7 year old boy presented with a history of recurrent episodes of sinusitis and otitis. He developed paresis of the external muscle of his right eye with exophthalmos. A biopsy of his sinus mucosa demonstrated necrotizing granulomatous involvement of the membranes with the presence of multiple giant cells interspersed in zones of fibrosis. A diagnosis of Wegener's granulomatosis was entertained. However the absence of pulmonary and renal manifestations did not allow for a definitive diagnosis to be made. He later developed hematuria and a renal biopsy demonstrated a renal lesions consistent with Wegener's granulomatosis. He has responded well to Cyclophosphamide and Prednisone therapy.
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