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von Stillfried S, Freeborn B, Windeck S, Boor P, Böcker J, Schmidt J, Tholen P, Röhrig R, Majeed R, Wienströer J, Bremer J, Weis J, Knüchel R, Breitbach A, Bülow RD, Cacchi C, Wucherpfennig S, Märkl B, Claus R, Dhillon C, Schaller T, Sipos E, Spring O, Braun G, Römmele C, Kling E, Kröncke T, Wittmann M, Hirschbühl K, Heppner FL, Meinhardt J, Radbruch H, Streit S, Horst D, Elezkurtaj S, Quaas A, Göbel H, Friemann J, Hansen T, Titze U, Lorenzen J, Reuter T, Woloszyn J, Baretton G, Hilsenbeck J, Meinhardt M, Pablik J, Sommer L, Holotiuk O, Meinel M, Esposito I, Crudele G, Seidl M, Mahlke N, Hartmann A, Haller F, Eichhorn P, Lange F, Amann KU, Coras R, Ingenwerth M, Rawitzer J, Schmid KW, Theegarten D, Gradhand E, Smith K, Wild P, Birngruber CG, Schilling O, Werner M, Acker T, Gattenlöhner S, Franz J, Metz I, Stadelmann C, Stork L, Thomas C, Zechel S, Ströbel P, Fathke C, Harder A, Wickenhauser C, Glatzel M, Matschke J, Krasemann S, Dietz E, Edler C, Fitzek A, Fröb D, Heinemann A, Heinrich F, Klein A, Kniep I, Lohner L, Möbius D, Ondruschka B, Püschel K, Schädler J, Schröder AS, Sperhake JP, Aepfelbacher M, Fischer N, Lütgehetmann M, Pfefferle S, Jonigk D, Werlein C, Domke LM, Hartmann L, Klein I, Schirmacher P, Schwab C, Röcken C, Langer D, Roth W, Strobl S, Rudelius M, Delbridge C, Kasajima A, Kuhn PH, Slotta-Huspenina J, Weichert W, Weirich G, Stock K, Barth P, Schnepper A, Wardelmann E, Evert K, Evert M, Büttner A, Manhart J, Nigbur S, Bösmüller H, Fend F, Granai M, Klingel K, Warm V, Steinestel K, Umathum VG, Rosenwald A, Vogt N, Kurz F. [Update on collaborative autopsy-based research in German pathology, neuropathology, and forensic medicine]. Pathologie (Heidelb) 2022; 43:101-105. [PMID: 36114379 PMCID: PMC9483541 DOI: 10.1007/s00292-022-01117-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 08/30/2022] [Indexed: 01/02/2023]
Abstract
BACKGROUND Autopsies are a valuable tool for understanding disease, including COVID-19. MATERIALS AND METHODS The German Registry of COVID-19 Autopsies (DeRegCOVID), established in April 2020, serves as the electronic backbone of the National Autopsy Network (NATON), launched in early 2022 following DEFEAT PANDEMIcs. RESULTS The NATON consortium's interconnected, collaborative autopsy research is enabled by an unprecedented collaboration of 138 individuals at more than 35 German university and non-university autopsy centers through which pathology, neuropathology, and forensic medicine autopsy data including data on biomaterials are collected in DeRegCOVID and tissue-based research and methods development are conducted. More than 145 publications have now emerged from participating autopsy centers, highlighting various basic science and clinical aspects of COVID-19, such as thromboembolic events, organ tropism, SARS-CoV‑2 detection methods, and infectivity of SARS-CoV-2 at autopsy. CONCLUSIONS Participating centers have demonstrated the high value of autopsy and autopsy-derived data and biomaterials to modern medicine. The planned long-term continuation and further development of the registry and network, as well as the open and participatory design, will allow the involvement of all interested partners.
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Affiliation(s)
- Saskia von Stillfried
- Institut für Pathologie, Universitätsklinik RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Deutschland
| | - Benita Freeborn
- Institut für Pathologie, Universitätsklinik RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Deutschland
| | - Svenja Windeck
- Institut für Pathologie, Universitätsklinik RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Deutschland
| | - Peter Boor
- Institut für Pathologie, Universitätsklinik RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Deutschland ,Medizinische Klinik II (Nephrologie und Immunologie), Universitätsklinik RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Deutschland ,Elektronenmikroskopische Einrichtung, Universitätsklinik RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Deutschland
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Sommer L, Combs S, Breitkreutz H, Chemnitz T, Wilkens J. PO-1517: Development and validation of a 3D dose calculation software for neutron radiotherapy. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)01535-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Reis KP, Sperling LE, Teixeira C, Sommer L, Colombo M, Koester LS, Pranke P. VPA/PLGA microfibers produced by coaxial electrospinning for the treatment of central nervous system injury. ACTA ACUST UNITED AC 2020; 53:e8993. [PMID: 32294700 PMCID: PMC7162582 DOI: 10.1590/1414-431x20208993] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 01/27/2020] [Indexed: 12/20/2022]
Abstract
The central nervous system shows limited regenerative capacity after injury. Spinal cord injury (SCI) is a devastating traumatic injury resulting in loss of sensory, motor, and autonomic function distal from the level of injury. An appropriate combination of biomaterials and bioactive substances is currently thought to be a promising approach to treat this condition. Systemic administration of valproic acid (VPA) has been previously shown to promote functional recovery in animal models of SCI. In this study, VPA was encapsulated in poly(lactic-co-glycolic acid) (PLGA) microfibers by the coaxial electrospinning technique. Fibers showed continuous and cylindrical morphology, randomly oriented fibers, and compatible morphological and mechanical characteristics for application in SCI. Drug-release analysis indicated a rapid release of VPA during the first day of the in vitro test. The coaxial fibers containing VPA supported adhesion, viability, and proliferation of PC12 cells. In addition, the VPA/PLGA microfibers induced the reduction of PC12 cell viability, as has already been described in the literature. The biomaterials were implanted in rats after SCI. The groups that received the implants did not show increased functional recovery or tissue regeneration compared to the control. These results indicated the cytocompatibility of the VPA/PLGA core-shell microfibers and that it may be a promising approach to treat SCI when combined with other strategies.
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Affiliation(s)
- K P Reis
- Laboratório de Hematologia e Células-tronco, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.,Laboratório de Células-tronco, Instituto de Ciências da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.,Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - L E Sperling
- Laboratório de Hematologia e Células-tronco, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.,Laboratório de Células-tronco, Instituto de Ciências da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.,Curso de Medicina, Escola da Saúde, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, Brasil
| | - C Teixeira
- Laboratório de Hematologia e Células-tronco, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.,Laboratório de Células-tronco, Instituto de Ciências da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - L Sommer
- Laboratório de Hematologia e Células-tronco, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.,Laboratório de Células-tronco, Instituto de Ciências da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - M Colombo
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - L S Koester
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - P Pranke
- Laboratório de Hematologia e Células-tronco, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.,Laboratório de Células-tronco, Instituto de Ciências da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.,Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.,Instituto de Pesquisa com Células-tronco, Porto Alegre, RS, Brasil
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Diener J, Baggiolini A, Dalcher D, Tuncer E, Levesque M, Dummer R, Santoro R, Treier M, Sommer L. PO-160 Downregulation of the oncofetal gene SALL4 in melanoma leads to invasion and metastasis by differential acetylation mediated through binding to HDACs. ESMO Open 2018. [DOI: 10.1136/esmoopen-2018-eacr25.199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Kavakli K, Demartis F, Karimi M, Eshghi P, Neme D, Chambost H, Sommer L, Zak M, Benson G. Safety and effectiveness of room temperature stable recombinant factor VIIa in patients with haemophilia A or B and inhibitors: Results of a multinational, prospective, observational study. Haemophilia 2017; 23:575-582. [PMID: 28440004 DOI: 10.1111/hae.13227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2017] [Indexed: 01/19/2023]
Abstract
INTRODUCTION A room temperature stable formulation of recombinant activated factor VII (NovoSeven® ), allowing convenient storage and therefore improved treatment access, has been developed. Bioequivalence to the previous NovoSeven® was demonstrated in healthy humans, leading to European approval (2008). Although no confirmed cases of neutralising antibodies to rFVIIa in patients with haemophilia A or B have been observed with the original formulation, changes in formulation or storage condition may alter immunogenicity. AIM SMART-7™ was designed to investigate the safety of NovoSeven® in a real-world setting in patients with haemophilia A or B with inhibitors. METHODS Study medication was not provided by the sponsor, and treatment was at the discretion of the treating physician, in accordance with the local label. Patient baseline information was collected at enrolment. Information on safety, drug exposure and bleeding episodes was collected and FVII antibody screening was encouraged at baseline and performed at the investigator's discretion. RESULTS Fifty-one patients were enrolled and 31 completed the study. Forty-one adverse events (AEs) were reported in 23 patients; 25 AEs in 14 patients were serious. No thromboembolic events were observed. Although four cases of reduced therapeutic response were reported, FVII antibody screening was negative. Forty-eight patients experienced 618 bleeding episodes and 93.4% of 609 evaluated bleeds were stopped by treatment. Of the 538 bleeding episodes treated with NovoSeven® monotherapy, 94.2% stopped by end of treatment. CONCLUSION Data collected during the SMART-7™ study revealed no treatment-related safety issues and no FVII-binding antibodies for patients treated with NovoSeven® under real-world conditions.
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Affiliation(s)
- K Kavakli
- Department of Hematology, Ege University Children's Hospital, Izmir, Turkey
| | - F Demartis
- Careggi Agenzia per l'Emofilia, A.O.U.C. Azienda Ospedaliero-Universitaria, Firenze, Italy
| | - M Karimi
- Hematology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - P Eshghi
- Pediatric Congenital Hematologic Disorders Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - D Neme
- Fundación de la Hemofilia, Buenos Aires, Argentina
| | - H Chambost
- Service d'Hématologie Oncologie Pédiatrique, La Timone, APHM, Marseille, France.,Inserm, UMR 1062, Faculté de Médecine, Aix-Marseille Université, Marseille, France
| | - L Sommer
- Biostatistics Biopharm, Global Development, Novo Nordisk A/S, Søborg, Denmark
| | - M Zak
- Medical and Science Haemophilia, Global Development, Novo Nordisk A/S, Søborg, Denmark
| | - G Benson
- Northern Ireland Haemophilia Comprehensive Care Centre, Belfast City Hospital, Belfast, UK
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Arenas-Ramirez N, Zou C, Popp S, Zingg D, Brannetti B, Wirth E, Calzascia T, Kovarik J, Sommer L, Zenke G, Woytschak J, Regnier CH, Katopodis A, Boyman O. Improved cancer immunotherapy by a CD25-mimobody conferring selectivity to human interleukin-2. Sci Transl Med 2016; 8:367ra166. [DOI: 10.1126/scitranslmed.aag3187] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 06/08/2016] [Accepted: 09/08/2016] [Indexed: 12/31/2022]
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Michel L, Sommer L, González Silos R, Lorenzo Bermejo J, Hennigs A, Golatta M, Heil J, Schneeweiss A, Sohn C, Marmé F. Evaluation des MD Anderson Prognostic Index (MDAPI) zur lokoregionären Risikostratifikation in der neoadjuvanten Therapiesituation. Geburtshilfe Frauenheilkd 2016. [DOI: 10.1055/s-0036-1592811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Zingg D, Arenas-Ramirez N, Rosalia R, Antunes A, Haeusel J, Boyman O, Sommer L. The epigenetic repressor EZH2 controls tumour escape mechanisms during immunotherapy. Eur J Cancer 2016. [DOI: 10.1016/s0959-8049(16)61221-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Tuncer E, Zingg D, Cheng P, Antunes A, Haeusel J, Deng C, Kleiter I, Sommer L. Role of integrated TGF-β superfamily signaling in melanoma progression. Eur J Cancer 2016. [DOI: 10.1016/s0959-8049(16)61327-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Gladilovich DB, Kubán V, Sommer L. Determination of the sum of rare-earth elements by flow-injection analysis with Arsenazo III, 4-(2-pyridylazo)resorcinol, Chrome Azurol S and 5-bromo-2-(2-pyridylazo)-5-diethylaminophenol spectrophotometric reagents. Talanta 2012; 35:259-65. [PMID: 18964509 DOI: 10.1016/0039-9140(88)80082-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/1987] [Accepted: 11/21/1987] [Indexed: 10/18/2022]
Abstract
The reactivity of Arsenazo III, Chrome Azurol S in the presence of cetyltrimethylammonium or cetylpyridinium bromide, 4-(2-pyridylazo)resorcinol and 5-bromo-2-(2-pyridylazo)-5-diethylaminophenol with various rare-earth elements (REE) has been studied and the optimum conditions have been established for the spectrophotometric determination of REE with stationary and flow systems. Arsenazo III is the most suitable for the determination of the sum of REE, especially La, Ce, Nd, by FIA with spectrophotometric detection at 660 nm, in systems containing 0.04 mM reagent and 0.2M formate buffer (pH 3) and for sample volumes of 30 mul. The detection limits are 10.8 ng La, 11.0 ng Ce and 9.4 ng Nd in 30 mul. Limited amounts of Fe(III) and Al(III) are screened with 10 mM ascorbic and 5-sulphosalicylic acids. The sum of the REE is obtained from calibration plots prepared with La(III) standard solutions. The method has been successfully used for apatites and REE oxide concentrates after various kinds of decomposition.
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Affiliation(s)
- D B Gladilovich
- Department of Analytical Chemistry, J. E. Purkyne University, 611 37 Brno, Czechoslovakia
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Ostergaard JR, Ostergaard K, Andersson KE, Sommer L. Calcium antagonistic effects of terodiline in rabbit aorta and human uterus. Acta Pharmacol Toxicol (Copenh) 2009; 46 Suppl 1:12-9. [PMID: 7386217 DOI: 10.1111/j.1600-0773.1980.tb03243.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The possible calcium antagonistic action of the anti-anginal drug terodiline was investigated by two experimental techniques. In isolated preparations of rabbit aorta and pregnant human uterus exposed to a calcium-free medium and then depolarized by potassium, terodiline in concentrations of 4.5--36 microM inhibited contractions produced by cumulative addition of calcium to the extracellular medium. This effect of terodiline could be reversed by high concentrations of calcium. Within the same concentration range, terodiline also reduced potassium-induced 45Ca influx in isolated aorta without affecting calcium efflux. It is suggested that terodiline, which structurally has similarities to prenylamine and fendiline, like these drugs can be classified as a calcium antagonist.
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Husted S, Andersson KE, Sommer L, Ostergaard JR. Anticholinergic and calcium antagonistic effects of terodiline in rabbit urinary bladder. Acta Pharmacol Toxicol (Copenh) 2009; 46 Suppl 1:20-30. [PMID: 7386218 DOI: 10.1111/j.1600-0773.1980.tb03244.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The effects of terodiline on contractions induced in isolated rabbit detrusor by carbachol and potassium, and by electrical field stimulation were investigated. Terodiline relaxed preparations contracted by carbachol and potassium and, when added 15 min before stimulation, decreased the contractile responses to these agents in a concentration-dependent way. Terodiline more effectively inhibited carbachol than potassium induced contractions. The "pure" calcium antagonist nifedipine had the opposite effect. Both atropine and terodiline caused a parallel shift to the right of the concentration-response curve to carbachol. The maximum contractile tension and slope were not affected, suggesting a competitive antimuscarinic effect within the concentration range used. Atropine was approximately 750 times more potent than terodiline. The maximum inhibitory effect of atropine and the calcium antagonist nimodipine on the electrically induced response were 40% and 69%, respectively. Terodiline caused complete inhibition of the response, as also did a combination of nimodipine and atropine. --The results suggest that terodiline in low concentrations has mainly an antimuscarinic action. To this, a calcium antagonistic effect is added at higher concentrations. The two-fold action of the drug makes it an effective inhibitor of bladder contraction, and an interesting tool for investigations of bladder contractility.
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Dasgupta-Schubert N, Alexander S, Sommer L, Whelan T, Alfaro Cuevas Villanueva R, Mendez Lopez ME, Persans MW. The Light Quanta Modulated Physiological Response ofBrassica Juncea Seedlings Subjected to Ni(II) Stress. Eng Life Sci 2007. [DOI: 10.1002/elsc.200620187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Sommer L. [Stem cells of the enteric nervous system: causal therapy for Hirschsprung's disease?]. Pathologe 2007; 28:125-30. [PMID: 17277920 DOI: 10.1007/s00292-007-0891-0] [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] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Stem cells are self-renewing cells with the potential to generate different cell types. The human organism depends on stem cells for organ development during embryogenesis. Upon completion of organogenesis, stem cells are also necessary for organ maintenance ("homeostasis") and for tissue regeneration. In view of the manifold functions of stem cells, it is not surprising that their malfunction results in diseases like Hirschsprung's disease, a disorder of the enteric nervous system of complex etiology. Potential stem cell application for the regeneration of diseased organs, such as the enteric nervous system in Hirschsprung's disease, is currently a focus of intense research.
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Affiliation(s)
- L Sommer
- Abteilung für Biologie, Institut für Zellbiologie, ETH Zürich-Hönggerberg, Schafmattstrasse 18, 8093 Zürich, Switzerland.
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Sommer L. [S4]: Multipotent neural crest‐derived cells in the developing and adult organism. Int J Dev Neurosci 2006. [DOI: 10.1016/j.ijdevneu.2006.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Martos J, Gastal MT, Sommer L, Lund RG, Del Pino FAB, Osinaga PWR. Dissolving efficacy of organic solvents on root canal sealers. Clin Oral Investig 2005; 10:50-4. [PMID: 16317555 DOI: 10.1007/s00784-005-0023-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Accepted: 10/25/2005] [Indexed: 11/28/2022]
Abstract
The aim of this study was to evaluate the solubility of three types of root canal sealers in three organic solvents used in endodontics. The solubility of calcium-hydroxide-based (Sealer 26), silicon-polydimethylsiloxane-based (RoekoSeal), and zinc-oxide-eugenol based (Endofill and Intrafill) sealers was assessed in eucalyptol, xylol, orange oil, and distilled water. Eighty samples of each filling material were prepared according to the manufacturers' instructions and then divided into four groups for immersion in solvent for 2 or 10 min. The means of sealer dissolution in solvents were obtained by the difference between the original preimmersion weight and the postimmersion weight in a digital analytical scale. Data were statistically analyzed with the Student's t test, and multiple comparisons were performed with Student-Newman-Keuls. Xylol and orange oil showed similar effects, with significant solubilization (P<0.05) of the tested cements. Endofill and Sealer 26 did not show any significant difference in solubilization at the two immersion times, whereas RoekoSeal and Intrafill showed a more pronounced solubility at 10 min. The lowest levels of solubilization occurred in RoekoSeal, Sealer 26, Endofill, and Intrafill. It is concluded that xylol and orange oil presented similar solvent effects with a significant solubility of the tested cements.
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Affiliation(s)
- J Martos
- Department of Clinics, Pelotas Dental School, Federal University of Pelotas, Rua Gonçalves Chaves 457, 96015-560 Pelotas, Rio Grande do Sul, Brazil.
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Abstract
Wnt signaling has proven to be essential for neural development at various stages and across species. Wnts are involved in morphogenesis and patterning, and their proliferation-promoting role is a key function in stem cell maintenance and the expansion of progenitor pools. Moreover, Wnt signaling is involved in differentiation processes and lineage decision events during both central and peripheral nervous system development. Additionally, several reports point to a role of Wnt signaling in axon guidance and neurite outgrowth. This article reviews and consolidates the existing evidence for the functions of Wnt signaling in neural development.
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Affiliation(s)
- F Ille
- Institute of Cell Biology, Department of Biology, Swiss Federal Institute of Technology, Zürich
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Pietrusza E, Sommer L, Whitmore F. Additions and Corrections - A New Synthesis of Organosilicon Compounds. J Am Chem Soc 2002. [DOI: 10.1021/ja01192a626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Paratore C, Goerich DE, Suter U, Wegner M, Sommer L. Survival and glial fate acquisition of neural crest cells are regulated by an interplay between the transcription factor Sox10 and extrinsic combinatorial signaling. Development 2001; 128:3949-61. [PMID: 11641219 DOI: 10.1242/dev.128.20.3949] [Citation(s) in RCA: 243] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The transcription factor Sox10 is required for proper development of various neural crest-derived cell types. Several lineages including melanocytes, autonomic and enteric neurons, and all subtypes of peripheral glia are missing in mice homozygous for Sox10 mutations. Moreover, haploinsufficiency of Sox10 results in neural crest defects that cause Waardenburg/Hirschsprung disease in humans. We provide evidence that the cellular basis to these phenotypes is likely to be a requirement for Sox10 by neural crest stem cells before lineage segregation. Cell death is increased in undifferentiated, postmigratory neural crest cells that lack Sox10, suggesting a role of Sox10 in the survival of neural crest cells. This function is mediated by neuregulin, which acts as a survival signal for postmigratory neural crest cells in a Sox10-dependent manner. Furthermore, Sox10 is required for glial fate acquisition, as the surviving mutant neural crest cells are unable to adopt a glial fate when challenged with different gliogenic conditions. In Sox10 heterozygous mutant neural crest cells, survival appears to be normal, while fate specifications are drastically affected. Thereby, the fate chosen by a mutant neural crest cell is context dependent. Our data indicate that combinatorial signaling by Sox10, extracellular factors such as neuregulin 1, and local cell-cell interactions is involved in fine-tuning lineage decisions by neural crest stem cells. Failures in fate decision processes might thus contribute to the etiology of Waardenburg/Hirschsprung disease.
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Affiliation(s)
- C Paratore
- Institute of Cell Biology, Swiss Federal Institute of Technology, ETH-Hönggerberg, CH-8093 Zurich, Switzerland
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Abstract
A challenging problem in neural crest development is to understand how a migratory population of multipotent stem cells gives rise to a diverse array of differentiated cell types in the correct spatiotemporal manner. There is now ample evidence that this process involves the generation of postmigratory progenitor cells present in a variety of neural crest targets. When individual progenitors are challenged by instructive growth factors they are able to produce neural and non-neural cells, raising the question of how fate restrictions appropriate to a given embryonic location are regulated in multipotent postmigratory progenitor cells. Although some of the extracellular cues involved have been identified, it is likely that fate decisions in progenitor cells are controlled by the combinatorial action of multiple environmental signals. Moreover, cell type specificity is thought to be regulated by an interplay between extracellular and intracellular cues. We are just beginning to unravel some of the mechanisms that allow the context-dependent integration of cell-extrinsic and cell-intrinsic signals in multipotent progenitor cells.
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Affiliation(s)
- L Sommer
- Institute of Cell Biology, Swiss Federal Institute of Technology, ETH-Hönggerberg, Zürich.
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Brault V, Moore R, Kutsch S, Ishibashi M, Rowitch DH, McMahon AP, Sommer L, Boussadia O, Kemler R. Inactivation of the (β)-catenin gene by Wnt1-Cre-mediated deletion results in dramatic brain malformation and failure of craniofacial development. Development 2001; 128:1253-64. [PMID: 11262227 DOI: 10.1242/dev.128.8.1253] [Citation(s) in RCA: 789] [Impact Index Per Article: 34.3] [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] [Indexed: 11/20/2022]
Abstract
('bgr;)-Catenin is a central component of both the cadherin-catenin cell adhesion complex and the Wnt signaling pathway. We have investigated the role of (β)-catenin during brain morphogenesis, by specifically inactivating the (β)-catenin gene in the region of Wnt1 expression. To achieve this, mice with a conditional ('floxed') allele of (β)-catenin with required exons flanked by loxP recombination sequences were intercrossed with transgenic mice that expressed Cre recombinase under control of Wnt1 regulatory sequences. (β)-catenin gene deletion resulted in dramatic brain malformation and failure of craniofacial development. Absence of part of the midbrain and all of the cerebellum is reminiscent of the conventional Wnt1 knockout (Wnt1(−)(/)(−)), suggesting that Wnt1 acts through (β)-catenin in controlling midbrain-hindbrain development. The craniofacial phenotype, not observed in embryos that lack Wnt1, indicates a role for (β)-catenin in the fate of neural crest cells. Analysis of neural tube explants shows that (β)-catenin is efficiently deleted in migrating neural crest cell precursors. This, together with an increased apoptosis in cells migrating to the cranial ganglia and in areas of prechondrogenic condensations, suggests that removal of (β)-catenin affects neural crest cell survival and/or differentiation. Our results demonstrate the pivotal role of (β)-catenin in morphogenetic processes during brain and craniofacial development.
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Affiliation(s)
- V Brault
- Department of Molecular Embryology, Max-Planck Institute of Immunobiology, Stuebeweg 51, D-79108 Freiburg, Germany
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Abstract
BACKGROUND Notch signaling regulates multiple differentiation processes and cell fate decisions during both invertebrate and vertebrate development. Numb encodes an intracellular protein that was shown in Drosophila to antagonize Notch signaling at binary cell fate decisions of certain cell lineages. Although overexpression experiments suggested that Numb might also antagonize some Notch activity in vertebrates, the developmental processes in which Numb is involved remained elusive. RESULTS We generated mice with a homozygous inactivation of Numb. These mice died before embryonic day E11.5, probably because of defects in angiogenic remodeling and placental dysfunction. Mutant embryos had an open anterior neural tube and impaired neuronal differentiation within the developing cranial central nervous system (CNS). In the developing spinal cord, the number of differentiated motoneurons was reduced. Within the peripheral nervous system (PNS), ganglia of cranial sensory neurons were formed. Trunk neural crest cells migrated and differentiated into sympathetic neurons. In contrast, a selective differentiation anomaly was observed in dorsal root ganglia, where neural crest--derived progenitor cells had migrated normally to form ganglionic structures, but failed to differentiate into sensory neurons. CONCLUSIONS Mouse Numb is involved in multiple developmental processes and required for cell fate tuning in a variety of lineages. In the nervous system, Numb is required for the generation of a large subset of neuronal lineages. The restricted requirement of Numb during neural development in the mouse suggests that in some neuronal lineages, Notch signaling may be regulated independently of Numb.
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Affiliation(s)
- O Zilian
- Swiss Institute for Experimental Cancer Research (ISREC), 155 Chemin des Boveresses, CH-1066 Epalinges s/ Lausanne, Switzerland
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Hagedorn L, Floris J, Suter U, Sommer L. Autonomic neurogenesis and apoptosis are alternative fates of progenitor cell communities induced by TGFbeta. Dev Biol 2000; 228:57-72. [PMID: 11087626 DOI: 10.1006/dbio.2000.9936] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [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: 12/13/2022]
Abstract
The question of how appropriate cell types are generated in correct numbers during development of the peripheral nervous system has become particularly intriguing with the identification of multipotent progenitor cells in postmigratory targets of the neural crest. Recently, we have provided evidence that community effects in response to factors of the TGFbeta family might represent a mechanism to suppress inappropriate nonneural fates from multipotent progenitors in developing peripheral ganglia. In culture, BMP2 and TGFbeta promote neurogenesis at the expense of a smooth-muscle-like fate in clusters of neural-crest-derived multipotent progenitor cells. We now show that the neurons generated by TGFbeta factors belong to the autonomic lineage and that cells within the developing sympathetic ganglia express TGFbeta-type II receptor. In addition to its neurogenic activity, TGFbeta but not BMP2 also induces apoptosis as an alternative fate in cultured progenitor communities. Interestingly, these fate decisions are controlled by graded changes in TGFbeta concentrations: lower doses of TGFbeta promote neurogenesis while slightly higher doses induce predominantly apoptosis. These effects of TGFbeta are specific for an early developmental stage since progenitor cells lose their competence to respond to the proapoptotic activity of TGFbeta upon neuronal differentiation. In vivo, the expression of TGFbeta3 in differentiated neurons suggests that the signal concentration gradually increases with the number of neurons formed in the autonomic ganglia. We propose that TGFbeta functions in a biphasic manner during autonomic gangliogenesis to control both neurogenesis and subsequently the number of neurons generated from progenitor cells.
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Affiliation(s)
- L Hagedorn
- Institute of Cell Biology, Swiss Federal Institute of Technology, ETH-Hönggerberg, Zurich, CH-8093, Switzerland
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Sommer L, Vlašánková R. A survey of the potential of the high performance liquid chromatography and capillary zone electrophoresis for the determination of platinum and platinum group metals. Chromatographia 2000. [DOI: 10.1007/bf02490992] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Hagedorn L, Paratore C, Brugnoli G, Baert JL, Mercader N, Suter U, Sommer L. The Ets domain transcription factor Erm distinguishes rat satellite glia from Schwann cells and is regulated in satellite cells by neuregulin signaling. Dev Biol 2000; 219:44-58. [PMID: 10677254 DOI: 10.1006/dbio.1999.9595] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [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: 12/13/2022]
Abstract
Distinct glial cell types of the vertebrate peripheral nervous system (PNS) are derived from the neural crest. Here we show that the expression of the Ets domain transcription factor Erm distinguishes satellite glia from Schwann cells beginning early in rat PNS development. In developing dorsal root ganglia (DRG), Erm is present both in presumptive satellite glia and in neurons. In contrast, Erm is not detectable at any developmental stage in Schwann cells in peripheral nerves. In addition, Erm is downregulated in DRG-derived glia adopting Schwann cell traits in culture. Thus, Erm is the first described transcription factor expressed in satellite glia but not in Schwann cells. In culture, the Neuregulin1 (NRG1) isoform GGF2 maintains Erm expression in presumptive satellite cells and reinduces Erm expression in DRG-derived glia but not in Schwann cells from sciatic nerve. These data demonstrate that there are intrinsic differences between these glial subtypes in their response to NRG1 signaling. In neural crest cultures, Erm-positive progenitor cells give rise to two distinct glial subtypes: Erm-positive, Oct-6-negative satellite glia in response to GGF2, and Erm-negative, Oct-6-positive Schwann cells in the presence of serum and the adenylate cyclase activator forskolin. Thus, Erm-positive neural crest-derived progenitor cells and presumptive satellite glia are able to acquire Schwann cell features. Given the in vivo expression of Erm in peripheral ganglia, we suggest that ganglionic Erm-positive cells may be precursors of Schwann cells.
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Affiliation(s)
- L Hagedorn
- Institute of Cell Biology, Swiss Federal Institute of Technology, ETH-Hönggerberg, CH-8093, Switzerland
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Schatten H, Chakrabarti A, Taylor M, Sommer L, Levine H, Anderson K, Runco M, Kemp R. Effects of spaceflight conditions on fertilization and embryogenesis in the sea urchin Lytechinus pictus. Cell Biol Int 2000; 23:407-15. [PMID: 10623420 DOI: 10.1006/cbir.1999.0371] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Calcium loss and muscle atrophy are two of the main metabolic changes experienced by astronauts and crew members during exposure to microgravity in space. Calcium and cytoskeletal events were investigated within sea urchin embryos which were cultured in space under both microgravity and 1 g conditions. Embryos were fixed at time-points ranging from 3 h to 8 days after fertilization. Investigative emphasis was placed upon: (1) sperm-induced calcium-dependent exocytosis and cortical granule secretion, (2) membrane fusion of cortical granule and plasma membranes; (3) microfilament polymerization and microvilli elongation; and (5) embryonic development into morula, blastula, gastrula, and pluteus stages. For embryos cultured under microgravity conditions, the processes of cortical granule discharge, fusion of cortical granule membranes with the plasma membrane, elongation of microvilli and elevation of the fertilization coat were reduced in comparison with embryos cultured at 1 g in space and under normal conditions on Earth. Also, 4% of all cells undergoing division in microgravity showed abnormalities in the centrosome-centriole complex. These abnormalities were not observed within the 1 g flight and ground control specimens, indicating that significant alterations in sea urchin development processes occur under microgravity conditions.
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Affiliation(s)
- H Schatten
- Department of Veterinary Pathobiology, University of Missouri-Columbia,MO 65211, USA.
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Hagedorn L, Suter U, Sommer L. P0 and PMP22 mark a multipotent neural crest-derived cell type that displays community effects in response to TGF-beta family factors. Development 1999; 126:3781-94. [PMID: 10433908 DOI: 10.1242/dev.126.17.3781] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Protein zero (P0) and peripheral myelin protein 22 (PMP22) are most prominently expressed by myelinating Schwann cells as components of compact myelin of the peripheral nervous system (PNS), and mutants affecting P0 and PMP22 show severe defects in myelination. Recent expression studies suggest a role of P0 and PMP22 not only in myelination but also during embryonic development. Here we show that, in dorsal root ganglia (DRG) and differentiated neural crest cultures, P0 is expressed in the glial lineage whereas PMP22 is also detectable in neurons. In addition, however, P0 and PMP22 are both expressed in a multipotent cell type isolated from early DRG. Like neural crest stem cells (NCSCs), this P0/PMP22-positive cell gives rise to glia, neurons and smooth-muscle-like cells in response to instructive extracellular cues. In cultures of differentiating neural crest, a similar multipotent cell type can be identified in which expression of P0 and PMP22 precedes the appearance of neural differentiation markers. Intriguingly, this P0/PMP22-positive progenitor exhibits fate restrictions dependent on the cellular context in which it is exposed to environmental signals. While single P0/PMP22-positive progenitor cells can generate smooth muscle in response to factors of the TGF-(beta) family, communities of P0/PMP22-positive cells interpret TGF-(beta) factors differently and produce neurons or undergo increased cell death instead of generating smooth-muscle-like cells. Our data are consistent with a model in which cellular association of postmigratory multipotent progenitors might be involved in the suppression of a non-neural fate in forming peripheral ganglia.
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Affiliation(s)
- L Hagedorn
- Institute of Cell Biology, Swiss Federal Institute of Technology, ETH-Hönggerberg, CH-8093 Zurich, Switzerland
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Apelqvist A, Li H, Sommer L, Beatus P, Anderson DJ, Honjo T, Hrabe de Angelis M, Lendahl U, Edlund H. Notch signalling controls pancreatic cell differentiation. Nature 1999; 400:877-81. [PMID: 10476967 DOI: 10.1038/23716] [Citation(s) in RCA: 865] [Impact Index Per Article: 34.6] [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: 02/06/2023]
Abstract
The pancreas contains both exocrine and endocrine cells, but the molecular mechanisms controlling the differentiation of these cell types are largely unknown. Despite their endodermal origin, pancreatic endocrine cells share several molecular characteristics with neurons, and, like neurons in the central nervous system, differentiating endocrine cells in the pancreas appear in a scattered fashion within a field of progenitor cells. This indicates that they may be generated by lateral specification through Notch signalling. Here, to test this idea, we analysed pancreas development in mice genetically altered at several steps in the Notch signalling pathway. Mice deficient for Delta-like gene 1 (Dll1) or the intracellular mediator RBP-Jkappa showed accelerated differentiation of pancreatic endocrine cells. A similar phenotype was observed in mice over-expressing neurogenin 3 (ngn 3) or the intracellular form of Notch3 (a repressor of Notch signalling). These data provide evidence that ngn3 acts as proendocrine gene and that Notch signalling is critical for the decision between the endocrine and progenitor/exocrine fates in the developing pancreas.
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Affiliation(s)
- A Apelqvist
- Department of Microbiology, University of Umeå, Sweden
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Abstract
Tyramide signal amplification has successfully been applied to enhance detection limits of both immunological reactions and in situ hybridization methods. The technique uses short-range deposition of activated tyramide mediated by horseradish peroxidase. We have adapted this method to fluorescence in situ hybridization on embryonic tissue sections using fluorophore-labeled tyramide. The sensitivity of the procedure was sufficient to analyze the embryonic expression of mRNAs encoding both transcription factors and structural proteins. Combining fluorescence in situ hybridization and immunofluorescence with confocal microscopy allows the simultaneous detection of distinct mRNA species or of mRNAs together with proteins on the cellular level. Thus, the cell types expressing a particular gene at a given developmental stage can be studied even if no antibody to the gene product of interest is available. Moreover, the technique allows to study in situ the combinatorial marker expression that characterizes progenitor stages of a given cell lineage.
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Affiliation(s)
- C Paratore
- Institute of Cell Biology, Swiss Federal Institute of Technology, Zürich
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Abstract
The striated muscle of the esophagus differs from other striated muscle, because it develops by the transdifferentiation of smooth muscle, and the motor end plates receive a dual innervation from vagal (cholinergic) motor neurons and nitric oxide synthase (NOS)-containing enteric neurons. Mash1-/- mice have no enteric neurons in their esophagus and die within 48 hours of birth without milk in their stomachs (Guillemot et al. [1993] Cell 75:463-476). In this study, the innervation of the esophagus of newborn Mash1-/-, Mash1+/- and wild type mice was examined. There was no difference between Mash1-/-, Mash1+/-, and wild type mice in the transdifferentiation of the muscle and the development of nicotinic receptor clusters. However, there were significantly more cholinergic nerve terminals per motor end plate in Mash1-/- mice than Mash1+/- or wild type mice. Each of the Mash1-/- mice had fewer than 50 NOS neurons per esophagus, compared with approximately 3,000 in wild type mice. Newborn Mash1+/- mice also contained significantly fewer NOS neurons than wild type mice. In Mash1-/- mice, NOS nerve fibers were virtually absent from the external muscle but were present at the myenteric plexus. Unlike that of newborn wild type mice, the lower esophageal sphincter of Mash 1-/- mice lacked NOS nerve fibers; this may explain the absence of milk in the stomach. We conclude that 1) the transdifferentiation of the esophageal muscle and the development of the extrinsic innervation do not require enteric neurons or MASH1, 2) extrinsic NOS neurons only innervate the myenteric plexus.
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Affiliation(s)
- Q Sang
- Department of Anatomy and Cell Biology, University of Melbourne, Parkville, Victoria, Australia
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Anderson DJ, Groves A, Lo L, Ma Q, Rao M, Shah NM, Sommer L. Cell lineage determination and the control of neuronal identity in the neural crest. Cold Spring Harb Symp Quant Biol 1998; 62:493-504. [PMID: 9598383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The molecular mechanisms underlying the determination of neuronal identity in the vertebrate peripheral nervous system are only just beginning to come into focus. Many of these mechanisms, such as the involvement of cascades of bHLH transcription factors and lateral inhibition via the Notch-Delta system, appear to have been conserved from Drosophila (Ghysen et al. 1993; Jan and Jan 1993). The way in which these genetic circuits are controlled by instructive growth factors, and the manner in which they lead to expression of a particular neuronal identity, is far from clear. This process is being elucidated by studies of neurogenesis in the peripheral autonomic lineage, which is arguably the best-understood neurogenic lineage in vertebrates. Emerging evidence is beginning to suggest that neuronal diversity within the autonomic and sensory lineages may be generated by related, but distinct, mechanisms. All autonomic progenitors express a common bHLH protein, MASH1, which appears to be induced by members of the BMP2 subfamily secreted by the tissues to which these progenitors migrate. Additional signals may then act on these progenitors in different locations to induce the expression of other transcription factors, which act in conjunction with MASH1 to specify the final phenotypes of the different autonomic neuron subtypes (sympathetic, parasympathetic, and enteric). Although different classes of autonomic neurons develop in very different locations within the body, different classes of sensory neurons are located together in dorsal root ganglia. The finding that distinct but related subtypes of bHLH proteins, the neurogenins, are expressed by different classes of sensory neuron precursors early in development suggests that sensory neuron diversity, in contrast to autonomic neuron diversity, may be pre-specified at or before the time neural crest cells begin their emigration from the neural tube.
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Affiliation(s)
- D J Anderson
- Howard Hughes Medical Institute, Division of Biology, California Institute of Technology, Pasadena 91125, USA
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Abstract
Recent data show that during development protein zero, P0, the most abundant peripheral nerve myelin protein, is detecable long before myelination. In particular, the expression of P0 in a fraction of migrating neural crest reveals progenitor cell heterogeneity in the developing PNS. Here we review the regulation and potential function of P0 during peripheral gliogenesis.
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Affiliation(s)
- L Sommer
- Institute of Cell Biology, Swiss Federal Institute of Technology, ETH-Hönggerberg, CH-8093 Zürich, Switzerland
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Abstract
BACKGROUND The interplay between growth factors and transcription factors in vertebrate neurogenesis is poorly understood. MASH1 is a basic helix-loop-helix (bHLH) transcription factor that is essential for autonomic neurogenesis. Bone morphogenetic protein (BMP) 2, and its relative BMP4, have been shown to induce expression of MASH1 and to promote autonomic neuronal differentiation in neural crest stem cells. The relationship between expression of MASH1 and the neurogenic competence of neural crest cells has not been investigated, however. RESULTS We have examined the function of MASH1 in neurogenic competence using a population of immuno-isolated neural-crest-derived progenitor cells. Post-migratory neural crest cells isolated from fetal rat gut expressed Mash1, yet comprised a mixture of committed neuronal precursors and non-neuronal cells. The non-neuronal cells remained competent to differentiate to neurons, however, if challenged with BMP2. Such competence declines with time and is paralleled by a decline in Mash1 expression in the cells. Expression of endogenous Mash1 can be maintained by BMP2; in turn, constitutive expression of Mash1 from a retroviral vector maintains competence for neuronal differentiation in response to late addition of BMP2. CONCLUSIONS These data suggest that MASH1 promotes competence for neurogenesis, in a manner similar to its homologs, the proneural genes achaete-scute in Drosophila. They also reveal an unexpected feedback interaction between BMP2 and MASH1 during neuronal differentiation. MASH1 may play multiple roles at successive stages of development within a neurogenic lineage, only one of which is revealed by a loss-of-function mutation.
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Affiliation(s)
- L Lo
- Division of Biology 216-76, Howard Hughes Medical Institute, California Institute of Technology, Pasadena, California 91125, USA
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Ma Q, Sommer L, Cserjesi P, Anderson DJ. Mash1 and neurogenin1 expression patterns define complementary domains of neuroepithelium in the developing CNS and are correlated with regions expressing notch ligands. J Neurosci 1997; 17:3644-52. [PMID: 9133387 PMCID: PMC6573688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Genetic studies in Drosophila and in vertebrates have implicated basic helix-loop-helix (bHLH) genes in neuronal fate determination and cell type specification. We have compared directly the expression of Mash1 and neurogenin1 (ngn1), two bHLH genes that are expressed specifically at early stages of neurogenesis. In the PNS these genes are expressed in complementary autonomic and sensory lineages. In the CNS in situ hybridization to serial sections and double-labeling experiments indicate that Mash1 and ngn1 are expressed in adjacent and nonoverlapping regions of the neuroepithelium that correspond to future functionally distinct areas of the brain. We also showed that in the PNS several other bHLH genes exhibit similar lineal restriction, as do ngn1 and Mash1, suggesting that complementary cascades of bHLH factors are involved in PNS development. Finally, we found that there is a close association between expression of ngn1 and Mash1 and that of two Notch ligands. These observations suggest a basic plan for vertebrate neurogenesis whereby regionalization of the neuroepithelium is followed by activation of a relatively small number of bHLH genes, which are used repeatedly in complementary domains to promote neural determination and differentiation.
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Affiliation(s)
- Q Ma
- Division of Biology 216-76, Howard Hughes Medical Institute, California Institute of Technology, Pasadena, California 91125, USA
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Kavanagh BP, Ngo C, Raymer K, Yang H, Alhashemi JA, Lui ACP, Reid D, Cicutti N, Krepski B, Wood G, Heyland DK, Badner NH, Murkin JM, Mohr J, McKenzie FN, van der Starre PJA, van Rooyen-Butijn WT, Wilson-Yang K, Teoh K, Lee RMKW, Hossain I, Cheng D, Karski J, Asokumar B, Sandier A, St-Amand MA, Murkin JM, Menkis AH, Downey DB, Nantau W, Adams S, Dowd N, Cheng D, Wong D, Carroll-Munro J, Trachuk C, Cregg N, Cheng DCH, Williams WG, Karski JM, Siu S, Webb G, Cheng DCH, Wong DT, Kustra R, Karski J, Tibshirani RJ, Côté DL, Lacey DE, LeDez KM, Smith JA, Crosby ET, Orkin FK, Fisher A, Volgyesi G, Silverman J, Edelstein S, Rucker J, Sommer L, Dunington S, Roy L, Crochetière C, Arsenault MY, Villeneuve E, Lortie L, Grange CS, Douglas MJ, Adams TJ, Merrick PM, Lucas SB, Morgan PJ, Halpern S, Lo J, Giesinger CL, Halpern SH, Breen TW, Vishnubala S, Shetty GR, De Kock M, Lagmiche A, Scholtes JL, Grodecki W, Duffy PJ, Hull KA, Hawboldt GS, Clark AJ, Smith JB, Norman RW, Beattie WS, Sandier A, Jewett M, Valiquette L, Katz J, Fradet Y, Redelmeier D, Sampson H, Cole J, Chedore T, Snedden W, Green RG, Sosis MB, Robles PI, Lazar ER, Jolly DT, Tarn YK, Tawfik SR, Clanachan AS, Milne A, Beamish T, Cuillerier DJ, Sharpe MD, Lee JK, Basta M, Krahn AD, Klein GJ, Yee R, Vakharia N, Francis H, Scheepers L, Vaghadia H, Carrier J, Martin R, Pirlet M, Claprood Y, Tétrault JP, Wong TD, Ryner L, Kozlowski P, Scarth G, Warrian RK, Lefevre G, Thiessen D, Girling L, Doiron L, McCudden C, Saunders J, Mutch WAC, Duffy PJ, Langevin S, Lessard MR, Trépanier CA, Hare GMT, Ngan JCS, Viskari D, Berrill A, Jodoin C, Couture J, Bellemare F, Farmer S, Muir H, Money P, Milne B, Parlow J, Raymond J, Williams JM, Craen RA, Novick T, Komar W, Frenette L, Cox J, Lockhart B, McArdle P, Eckhoff D, Bynon S, Dobkowski WB, Grant DR, Wall WJ, Chedrawy EG, Hall RI, Nedelcu V, Parlow J, Viale JP, Bégou G, Sagnard P, Hughson R, Quintin L, Troncy É, Collet JP, Shapiro S, Guimond JG, Blair L, Ducruet T, Francœur M, Charbonneau M, Blaise G, Snedden W, Bernadska E, Manson HI, Kutt JL, Mezon BY, Nishida O, Arellano R, Boylen P, DeMajo W, Archer DP, Roth SH, Raman S, Manninen P, Boyle K, Cenic A, Lee TY, Gelb AW, Reinders FX, Brown JIM, Baker AJ, Moulton RJ, Schlichtert L, Schwarz SKW, Puil E, Finegan BA, Finucane BT, Kurrek MM, Devitt JH, Morgan PJ, Cleave-Hogg D, Bradley J, Byrick R, Spadafora SM, Fuller JG, Gelula MH, Mayson K, Forster B, Byrick RJ, McKnight DJ, Kurrek M, Kolton M, Cleave-Hogg D, Haughton J, Halpern S, Kronberg J, Shysh S, Eagle C, Dagnone AJ, Parlow JL, Blaise G, Yang F, Nguyen H, Troncy E, Czaika G, Wachowski I, Basta M, Krahn AD, Yee R, Deladrière H, Cambier C, Pendeville P, Hung OR, Coonan E, Whynot SC, Mezei M, Coonan E, Whynot SC, Ho AMH, Luchsinger IS, Ling E, Mashava D, Chinyanga HM, Cohen MM, Shaw M, Robblee JA, Labow RS, Rubens FD, Diemunsch AM, Gervais R, Rose DK, Cohen MM, O’Brien-Pallas L, Copplestone C, Rose DK, Karkouti K, Sykora K, Cheung SLW, Booker PD, Franks R, Pozzi M, Guard B, Sikich N, Lerman J, Levine M, Swan H, Cox P, Montgomery C, Dunn G, Bourne R, Kinahan A, McCormack J, Dunn GS, Reimer EJ, Sanderson P, Sanderson PM, Montgomery CJ, Betts TA, Orlay GR, Wong DH, Cohen M, Al-Kaisy AA, Chan V, Peng P, Perlas A, Miniad A, Cushing EV, Mills KR, El-Beheiry H, Jahromi SS, Weaver J, Morris M, Carien PL, Cowan RM, Manninen P, Richards J, Robblee JA, Labow RS, Rubens FD, Menkis AH, Adams S, Henderson BT, Hudson RJ, Thomson IR, Moon M, Peterson MD, Rosenbloom M, Davison PJ, Ali M, Ali NS, Searle NR, Thomson I, Roy M, Gagnon L, Lye A, Walsh F, Middleton W, Wong D, Langer A, Errett L, Mazer CD, Karski J, Tibshirani RJ, Williamson KM, Smith G, Gnanendran KP, Bignell SJ, Jones S, Sleigh J, Arnell M, Schultz JAI, Fear DW, Ganapathy S, Moote C, Wassermann R, Watson J, Armstrong K, Calikyan AO, Yilmaz O, Kose Y, Peng P, Chan V, Chung F, Claxton AR, Krishnathas A, Mezei G, Badner NH, Paul TL, Doyle JA, Mehta M, DeLima LGR, Silva LEO, May WL, Maliakkal RJ, Mehta M, Kolesar R, Arellano R, Rafuse S, Fletcher M, Dunn G, Curran M, Bragg P, Chamberlain W, Crossan M, Ganapathy S, Sandhu H, Spadafora S, Mian R, Evans B, Hurst L, Katsiris S. Abstracts. Can J Anaesth 1997. [DOI: 10.1007/bf03022274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Abstract
Transmembrane receptor-type protein tyrosine phosphatases (RPTPs) form a novel and potentially important class of cell regulatory proteins. To identify RPTPs expressed during neural development we have characterized RPTPs transcribed in embryonic day (E)13.5 rat neural tube. Nine different phosphatases, one of which was novel, were identified. We examined the expression of the novel phosphatase, called RPTP psi, and of two other phosphatases, RPTP delta and RPTP mu, whose expression in the developing nervous system has not yet been described in detail. The expression of RPTP mu in small blood capillaries in developing neural tissue is consistent with an involvement in angiogenesis. In contrast, the temporally and spatially regulated expression of RPTP psi and RPTP delta in neuroepithelium suggests a role in early neural development. In the spinal cord, early expression of RPTP delta in the roof plate is followed by its expression in differentiating motor neurons. RPTP psi mRNA is also transiently detectable in the roof plate as well as in floor plate cells. In the telencephalon as well as in the hindbrain at E13.5, the reciprocal expression patterns of RPTP delta and RPTP psi are consistent with a sequential function, RPTP psi exerting its activity in undifferentiated progenitor cells and RPTP delta functioning during neuronal differentiation.
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Affiliation(s)
- L Sommer
- Howard Hughes Medical Institute, Division of Biology, California Institute of Technology, Pasadena 91125, USA
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Sommer L, Ma Q, Anderson DJ. neurogenins, a novel family of atonal-related bHLH transcription factors, are putative mammalian neuronal determination genes that reveal progenitor cell heterogeneity in the developing CNS and PNS. Mol Cell Neurosci 1996; 8:221-41. [PMID: 9000438 DOI: 10.1006/mcne.1996.0060] [Citation(s) in RCA: 451] [Impact Index Per Article: 16.1] [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: 02/03/2023] Open
Abstract
We recently identified neurogenin (ngn), a neuroD-related bHLH gene, whose Xenopus homolog functions as a neuronal determination factor and upstream activator of XneuroD (Ma et al. Cell 87: 43-52, 1996). Here we identify two additional ngn's, ngn2 and ngn3, which together define a novel subfamily of atonal-related mouse genes. Comparative analysis of ngn expression indicates that these three genes define distinct progenitor populations in the developing CNS and PNS, exhibiting nonoverlapping expression in some areas and partial overlap in others. The expression of the ngn's spatially overlaps and often temporally precedes that of neuroD, suggesting that (as in Xenopus) the ngn's and neuroD function in a cascade. Thus, as in myogenesis, different bHLH determination factors may activate a common bHLH differentiation factor in different sublineages. The ngn's therefore represent both a family of putative mammalian neuronal determination genes and useful markers of the origins of neuronal diversity.
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Affiliation(s)
- L Sommer
- Division of Biology 216-76, California Institute of Technology, Pasadena, California, 91125, USA
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Blaugrund E, Pham TD, Tennyson VM, Lo L, Sommer L, Anderson DJ, Gershon MD. Distinct subpopulations of enteric neuronal progenitors defined by time of development, sympathoadrenal lineage markers and Mash-1-dependence. Development 1996; 122:309-20. [PMID: 8565843 DOI: 10.1242/dev.122.1.309] [Citation(s) in RCA: 148] [Impact Index Per Article: 5.3] [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] [Indexed: 11/20/2022]
Abstract
Enteric and sympathetic neurons have previously been proposed to be lineally related. We present independent lines of evidence that suggest that enteric neurons arise from at least two lineages, only one of which expresses markers in common with sympathoadrenal cells. In the rat, sympathoadrenal markers are expressed, in the same order as in sympathetic neurons, by a subset of enteric neuronal precursors, which also transiently express tyrosine hydroxylase. If this precursor pool is eliminated in vitro by complement-mediated lysis, enteric neurons continue to develop; however, none of these are serotonergic. In the mouse, the Mash-1−/− mutation, which eliminates sympathetic neurons, also prevents the development of enteric serotonergic neurons. Other enteric neuronal populations, however, including those that contain calcitonin gene related peptide are present. Enteric tyrosine hydroxylase-containing cells co-express Mash-1 and are eliminated by the Mash-1−/− mutation, consistent with the idea that in the mouse, as in the rat, these precursors generate serotonergic neurons. Serotonergic neurons are generated early in development, while calcitonin gene related peptide-containing enteric neurons are generated much later. These data suggest that enteric neurons are derived from at least two progenitor lineages. One transiently expresses sympathoadrenal markers, is Mash-1-dependent, and generates early-born enteric neurons, some of which are serotonergic. The other is Mash-1-independent, does not express sympathoadrenal markers, and generates late-born enteric neurons, some of which contain calcitonin gene related peptide.
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Affiliation(s)
- E Blaugrund
- Department of Anatomy and Cell Biology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
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Abstract
Using primary cultures and immortalized multipotential stem cell lines derived from wild-type and Mash1 mutant neural crest cells, we have analyzed the cellular function of MASH1 in autonomic neurogenesis. We present evidence for the existence of a precursor expressing MASH1 and neuronal markers such as neurofilament, neuron-specific tubulin, and tetanus toxin receptor. This cell has a nonneuronal morphology. Differentiation of this precursor to neurons that express markers such as SCG10, peripherin, and neuron-specific enolase is dependent upon MASH1 function. These data imply that the differentiation of autonomic neurons from uncommitted neural crest cells occurs in several sequential steps. Moreover, they suggest that MASH1 does not commit multipotent cells to a neural fate, like its Drosophila achaete-scute counterparts, but rather promotes the differentiation of a committed neuronal precursor.
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Affiliation(s)
- L Sommer
- Division of Biology 216-76, California Institute of Technology, Pasadena 91125, USA
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Stoffel-Wagner B, Sommer L, Bidlingmaier F, Klingmüller D. Effects of the gonadotropin-releasing-hormone agonist, D-Trp-6-GnRH, on prolactin secretion in healthy young men. Horm Res 1995; 43:266-72. [PMID: 7541770 DOI: 10.1159/000184307] [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] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The objective of this study was to examine the changes in basal plasma gonadotropin, alpha-subunit, sex steroids, and prolactin levels and the prolactin and luteinizing hormone (LH) secretion pattern before, during and 161 days after treatment with a depot preparation of D-Trp-6-GnRH in young men. Gonadotropins, alpha-subunit, sex steroids, and prolactin were measured in pooled plasma samples. Additionally, before treatment, several times during its course and on day 161 after treatment, blood samples were drawn for 8 h every 15 min for prolactin and LH measurements. After initial stimulation of the pituitary, administration of a depot preparation of D-Trp-6-GnRH resulted in a constant decrease in gonadotropin and sex steroid concentrations with LH and testosterone concentrations remaining within the limits of prepubertal levels from days 16 to 48. Alpha-Subunit concentrations (0.4 +/- 0.09 IU/l; mean +/- SE) increased after application of D-Trp-6-GnRH, and remained elevated until day 48. Basal prolactin levels (3.5 +/- 0.25 microgram/l) did not change significantly during treatment but afterwards increased consistently with maximal levels at day 141 (15.3 +/- 3.8 microgram/l); they had decreased at day 161 to 10.3 +/- 1.8 microgram/l which is significantly higher than before treatment (p < 0.05). On day 161, prolactin pulse amplitude was significantly higher than before and during treatment (p<0.05), while no significant changes in pulse frequency occurred. No significant temporal coupling between LH and prolactin release could be detected.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- B Stoffel-Wagner
- Department of Clinical Biochemistry, University of Bonn, Germany
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Sommer L, Zanger K, Dyong T, Dorn C, Luckhaus J, Diedrich K, Klingmüller D. Seven-day administration of the gonadotropin-releasing hormone antagonist Cetrorelix in normal cycling women. Eur J Endocrinol 1994; 131:280-5. [PMID: 7921213 DOI: 10.1530/eje.0.1310280] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In contrast to gonadotropin-releasing hormone (GnRH) agonists, GnRH antagonists do not show any stimulatory effect on the pituitary but their clinical usage was precluded by severe side effects and high dose requirements. We report here on a 7-day treatment using the potent GnRH antagonist Cetrorelix ([Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10]GnRH) on five women 23-33 years old. All women were ovulatory and were studied during three consecutive cycles: a control cycle, a treatment cycle and a post-treatment control cycle. Throughout the control cycles blood samples were obtained daily during cycle days 8-18 and on days 21 and 23 during the remainder of the control cycles. On the eighth day of the treatment cycle women were hospitalized at 07.00 h for 26 h. Repeated blood samples were drawn at 15-min intervals during the entire period. Subjects received 3 mg of Cetrorelix sc for the first time at 09.00 h on the eighth day of the cycle and daily at 08.00 h for the following 6 days. Blood samples were obtained daily over a period of 25 days and every third day throughout the remainder of the treatment cycle. Twenty-four hours after the first application of Cetrorelix, luteinizing hormone (LH) and estradiol were in the subnormal range and remained subnormal until the end of medication. The suppressive effect of Cetrorelix compared to pretreatment values lasted at least 6 days for LH and FSH and 11 days after the last Cetrorelix injection for estradiol.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- L Sommer
- Department of Clinical Biochemistry, University of Bonn, Germany
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Abstract
Chronological changes in serum concentrations of inhibin, a gonadal glycoprotein hormone, were studied in healthy male volunteers (age 24-27 years). Secretion profiles of immunoreactive inhibin (ir-inhibin) were compared with those of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone. Blood samples were collected every 15 min for 24 h. Serum inhibin concentrations were measured by a two-site immunoenzymatic assay with antibodies raised against distinct epitopes of the recombinant 1-32 amino acids of the alpha-subunit of human inhibin. The normal range for men was 0.79-3.1 U/l x 10(-3), the sensitivity of the assay was 0.1 U/l x 10(-3) (cv: within-assay, 6.8%; between-assay, 8.2%). Luteinizing hormone and FSH were measured by immunoradiometric assay and testosterone by radioimmunoassay. Secretion profiles of inhibin and testosterone were tested for diurnal variations by cosinor rhythmometry. Highest ir-inhibin concentrations were observed in the morning at 08.00 h, with peak values of 2.45-3.20 U/l x 10(-3). During the evening and the night, ir-inhibin levels were relatively low; lowest concentrations were observed between 01.00 h and 02.00 h at night: 1.20-1.86 U/l x 10(-3). Highest testosterone levels were observed in the morning (20.5-36.6 pmol/l), lowest concentrations were detected at night (7.35-12.6 pmol/l). Cosinor rhythmometry supported the suggestion that there is a clear circadian secretion of ir-inhibin and testosterone, respectively. The secretion pattern of ir-inhibin was analyzed by the Cluster pulse analysis computed algorithm, which identified four to seven inhibin pulses per day, depending on the person under observation.2+ volunteers follow a clear diurnal rhythm.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- W Brennemann
- Institut für Klinische Biochemie, Universität Bonn, Germany
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Sommer L, Quade A, Hartmann K, Bidlingmaier F, Klingmüller D. Direct measurement of immunoreactive renin during changes of posture in man. Horm Res 1992; 37:171-5. [PMID: 1490659 DOI: 10.1159/000182304] [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: 12/27/2022]
Abstract
For several years, it has been possible to determine renin by a direct RIA. In the present study, plasma active renin concentration (PRC) was related to plasma renin activity (PRA) and aldosterone as a function of a standardized posture test. Using PRC, our target was to define the shortest necessary test duration. The three parameters were examined in 10 healthy male subjects (22-34 years old). Salt balance was determined in 24-hour urine, and plasma potassium and sodium were measured. Volunteers were hospitalized for 1 night, and at 8 a.m. the next morning they were subjected to the following postural changes: 3 h active orthostasis and 3 h recumbency. Frequent blood samples were taken. Orthostasis induced a significant rise in PRC, PRA and aldosterone already after 15 min. PRC and PRA reached a maximum level after 90 min of orthostasis and remained relatively stable, while aldosterone reached its highest level already after 30 min and then gradually decreased. Significant correlations were found between PRA and PRC (p < 0.001), between PRC and aldosterone (p < 0.001), and between PRA and aldosterone (p < 0.001). The PRC/PRA ratio changed during the course of the test, especially in supine subjects. When subjects returned to the supine position, all the parameters measured began a continual decrease. There were no significant changes in serum potassium and sodium levels throughout the duration of the test.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- L Sommer
- Institut für Klinische Biochemie, Rheinische Friedrich-Wilhelms-Universität, Bonn, BRD
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Sommer L, Hagenbüchle O, Wellauer PK, Strubin M. Nuclear targeting of the transcription factor PTF1 is mediated by a protein subunit that does not bind to the PTF1 cognate sequence. Cell 1991; 67:987-94. [PMID: 1720355 DOI: 10.1016/0092-8674(91)90371-5] [Citation(s) in RCA: 64] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The pancreas-specific transcription factor PTF1 is a heterooligomer that exists as two variants, alpha and beta, both of which bind DNA. The nucleus contains exclusively alpha while the cytoplasm contains both forms. Alpha and beta differ in protein composition. Reconstitution of alpha in vitro requires, in addition to the DNA-binding subunits common to both forms, a 75 kd glycosylated protein that apparently does not bind DNA. Here we show that this protein is essential for targeting PTF1 to the nucleus. Upon injection into frog oocytes, alpha is translocated quantitatively to the nucleus while beta remains in the cytoplasm. However, if beta is coinjected with purified 75 kd protein or a particular size fraction of pancreatic mRNA, it can be converted to alpha and imported into the nucleus.
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Affiliation(s)
- L Sommer
- Swiss Institute for Experimental Cancer Research, Epalinges
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Niggli V, Sommer L, Brunner J, Burger MM. Interaction in situ of the cytoskeletal protein vinculin with bilayers studied by introducing a photoactivatable fatty acid into living chicken embryo fibroblasts. Eur J Biochem 1990; 187:111-7. [PMID: 2105211 DOI: 10.1111/j.1432-1033.1990.tb15283.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The cytoskeletal protein vinculin, a putative actin--plasma-membrane linker, has been shown by hydrophobic photo-labeling to interact in vitro directly with bilayers of acidic phospholipids [Niggli et al. (1986) J. Biol. Chem. 261, 6912-6918]. In order to demonstrate that such an interaction occurs also in intact cells, chicken embryo fibroblasts were incubated for 2 h with a 3H-labeled photoactivatable fatty acid, 11-(4-[3-(trifluoromethyl)-diazirinyl]phenyl)-[2-3H]undecanoic acid. This resulted in biosynthetic incorporation into cellular lipids of a fraction of the fatty acid added. Following photolysis, vinculin was immunoprecipitated from different subcellular fractions using a specific polyclonal anti-vinculin antibody. The protein was recovered from both the cytosolic and the crude membrane fraction. Vinculin from both fractions incorporated label, but the membrane-associated population was at least eight times more strongly photolabeled than the cytosolic protein. Moreover, photolysis increased only labeling of the membrane-bound but not of the cytosolic protein. These results suggest that the direct interaction of vinculin with the hydrophobic core of the phospholipid layer observed in vitro may also be relevant in intact cells, and may be involved in its function as a linker protein.
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Affiliation(s)
- V Niggli
- Department of Biochemistry, University of Basel, Switzerland
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Sommer L, Ackermann G, Burns DT. Present and future status of organic analytical reagents - Part II. Inorganic chemical analysis: classical methods, molecular spectroscopy (absorption and emission) and solvent extraction. PURE APPL CHEM 1990. [DOI: 10.1351/pac199062122323] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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