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Jahn M, Lang V, Diehl S, Back R, Kaufmann R, Fauth T, Buerger C. Different immortalized keratinocyte cell lines display distinct capabilities to differentiate and reconstitute an epidermis in vitro. Exp Dermatol 2024; 33:e14985. [PMID: 38043130 DOI: 10.1111/exd.14985] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 09/21/2023] [Accepted: 10/22/2023] [Indexed: 12/05/2023]
Abstract
Dermatological research relies on the availability of suitable models that most accurately reflect the in vivo situation. Primary keratinocytes obtained from skin reduction surgeries are not only limited by availability but have a short lifespan and show donor-specific variations, which hamper the understanding of general mechanisms. The spontaneously immortalized keratinocyte cell line HaCaT displays chromosomal aberrations and is known to differentiate in an abnormal manner. To overcome these issues, we validated different engineered immortalized cell lines created from primary human keratinocytes (NHK) as model systems to study epidermal function. Cell lines either immortalized by the expression of SV40 large T antigen and hTERT (NHK-SV/TERT) or by transduction with HPV E6/E7 (NHK-E6/E7) were analysed for their growth and differentiation behaviour using 2D and 3D culture systems and compared to primary keratinocytes. Both cell lines displayed a robust proliferative behaviour but were still sensitive to contact inhibition. NHK-E6/E7 could be driven into differentiation by Ca2+ switch, while NHK-SV/TERT needed withdrawal from any proliferative signal to initiate a delayed onset of differentiation. In 3D epidermal models both cell lines were able to reconstitute a stratified epidermis and functional epidermal barrier. However, only NHK-E6/E7 showed a degree of epidermal maturation and stratification that was comparable to primary keratinocytes.
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Affiliation(s)
- Magdalena Jahn
- Department of Dermatology, Venerology and Allergology, Goethe University Frankfurt, University Hospital, Frankfurt am Main, Germany
| | - Victoria Lang
- Department of Dermatology, Venerology and Allergology, Goethe University Frankfurt, University Hospital, Frankfurt am Main, Germany
| | - Sandra Diehl
- Department of Dermatology, Venerology and Allergology, Goethe University Frankfurt, University Hospital, Frankfurt am Main, Germany
| | | | - Roland Kaufmann
- Department of Dermatology, Venerology and Allergology, Goethe University Frankfurt, University Hospital, Frankfurt am Main, Germany
| | | | - Claudia Buerger
- Department of Dermatology, Venerology and Allergology, Goethe University Frankfurt, University Hospital, Frankfurt am Main, Germany
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Ritzmann D, Jahn M, Heck S, Jung C, Cesetti T, Couturier N, Rudolf R, Reuscher N, Buerger C, Rauh O, Fauth T. The Ca 2+ channel TRPV4 is dispensable for Ca 2+ influx and cell volume regulation during hypotonic stress response in human keratinocyte cell lines. Cell Calcium 2023; 111:102715. [PMID: 36933289 DOI: 10.1016/j.ceca.2023.102715] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [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] [Received: 11/30/2022] [Revised: 03/02/2023] [Accepted: 03/09/2023] [Indexed: 03/13/2023]
Abstract
Cell swelling as a result of hypotonic stress is counteracted in mammalian cells by a process called regulatory volume decrease (RVD). We have recently discovered that RVD of human keratinocytes requires the LRRC8 volume-regulated anion channel (VRAC) and that Ca2+ exerts a modulatory function on RVD. However, the ion channel that is responsible for Ca2+ influx remains unknown. We investigated in this study whether the Ca2+-permeable TRPV4 ion channel, which functions as cell volume sensor in many cell types, may be involved in cell volume regulation during hypotonic stress response of human keratinocytes. We interfered with TRPV4 function in two human keratinocyte cell lines (HaCaT and NHEK-E6/E7) by using two TRPV4-specific inhibitors (RN1734 and GSK2193874), and by creating a CRISPR/Cas9-mediated genetic TRPV4-/- knockout in HaCaT cells. We employed electrophysiological patch clamp analysis, fluorescence-based Ca2+ imaging and cell volume measurements to determine the functional importance of TRPV4. We could show that both hypotonic stress and direct activation of TRPV4 by the specific agonist GSK1016790A triggered intracellular Ca2+ response. Strikingly, the Ca2+ increase upon hypotonic stress was neither affected by genetic knockout of TRPV4 in HaCaT cells nor by pharmacological inhibition of TRPV4 in both keratinocyte cell lines. Accordingly, hypotonicity-induced cell swelling, downstream activation of VRAC currents as well as subsequent RVD were unaffected both in TRPV4 inhibitor-treated keratinocytes and in HaCaT-TRPV4-/- cells. In summary, our study shows that keratinocytes do not require TRPV4 for coping with hypotonic stress, which implies the involvement of other, yet unidentified Ca2+ channels.
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Affiliation(s)
| | - Magdalena Jahn
- BRAIN Biotech AG, Zwingenberg, Germany; Department of Dermatology, Venerology and Allergology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | | | - Cristina Jung
- Membrane Biophysics, Department of Biology, TU Darmstadt, Darmstadt, Germany
| | - Tiziana Cesetti
- Institute of Molecular and Cell Biology, Hochschule Mannheim, Mannheim, Germany; Center for Mass Spectrometry and Optical Spectroscopy, Hochschule Mannheim, Mannheim, Germany
| | - Nathalie Couturier
- Institute of Molecular and Cell Biology, Hochschule Mannheim, Mannheim, Germany; Center for Mass Spectrometry and Optical Spectroscopy, Hochschule Mannheim, Mannheim, Germany
| | - Rüdiger Rudolf
- Institute of Molecular and Cell Biology, Hochschule Mannheim, Mannheim, Germany; Center for Mass Spectrometry and Optical Spectroscopy, Hochschule Mannheim, Mannheim, Germany
| | - Naemi Reuscher
- Department of Dermatology, Venerology and Allergology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Claudia Buerger
- Department of Dermatology, Venerology and Allergology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Oliver Rauh
- Membrane Biophysics, Department of Biology, TU Darmstadt, Darmstadt, Germany
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Fauth T, Jahn M, Rauh O, Buerger C. 178 The LRRC8 ion channel as novel drug target for psoriasis. J Invest Dermatol 2022. [DOI: 10.1016/j.jid.2022.09.189] [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: 11/19/2022]
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Jahn M, Lang V, Diehl S, Kaufmann R, Rauh O, Fauth T, Buerger C. 102 Loss of volume-regulated anion channel LRRC8 interferes with cell volume regulation and epidermal homeostasis. J Invest Dermatol 2021. [DOI: 10.1016/j.jid.2021.08.105] [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]
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Buerger C, Jahn M, Cruz V, Lang V, Diehl S, Ritzmann D, Back R, Kaufmann R, Fauth T. 121 Characterization of different immortalized keratinocyte cell lines as models for epidermal differentiation studies. J Invest Dermatol 2021. [DOI: 10.1016/j.jid.2021.08.124] [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]
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Abstract
In order to cope with external stressors such as changes in humidity and temperature or irritating substances, the epidermis as the outermost skin layer forms a continuously renewing and ideally intact protective barrier. Under certain circumstances, this barrier can be impaired and epidermal cells have to counteract cell swelling or shrinkage induced by osmotic stress via regulatory volume decrease (RVD) or increase (RVI). Here, we will review the current knowledge regarding the molecular machinery underlying RVD and RVI in the epidermis. Furthermore, we will discuss the current understanding how cell volume changes and its regulators are associated with epidermal renewal and barrier formation.
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Affiliation(s)
- Magdalena Jahn
- Department of Dermatology, Venerology and Allergology, University Hospital Frankfurt, Frankfurt am Main, Germany.,BRAIN AG, Zwingenberg, Germany
| | - Oliver Rauh
- Membrane Biophysics, Department of Biology, TU Darmstadt, Darmstadt, Germany
| | | | - Claudia Buerger
- Department of Dermatology, Venerology and Allergology, University Hospital Frankfurt, Frankfurt am Main, Germany,
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Cullmann K, Jahn M, Spindler M, Schenk F, Manukjan G, Mucci A, Steinemann D, Boller K, Schulze H, Bender M, Moritz T, Modlich U. Forming megakaryocytes from murine-induced pluripotent stem cells by the inducible overexpression of supporting factors. Res Pract Thromb Haemost 2020; 5:111-124. [PMID: 33537535 PMCID: PMC7845061 DOI: 10.1002/rth2.12453] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 01/19/2023] Open
Abstract
Background Platelets are small anucleate cells that circulate in the blood in a resting state but can be activated by external cues. In case of need, platelets from blood donors can be transfused. As an alternative source, platelets can be produced from induced pluripotent stem cells (iPSCs); however, recovered numbers are low. Objectives To optimize megakaryocyte (MK) and platelet output from murine iPSCs, we investigated overexpression of the transcription factors GATA‐binding factor 1 (GATA1); nuclear factor, erythroid 2; and pre–B‐cell leukemia transcription factor 1 (Pbx1) and a hyperactive variant of the small guanosine triphosphatase RhoA (RhoAhc). Methods To avoid off‐target effects, we generated iPSCs carrying the reverse tetracycline‐responsive transactivator M2 (rtTA‐M2) in the Rosa26 locus and expressed the factors from Tet‐inducible gammaretroviral vectors. Differentiation of iPSCs was initiated by embryoid body (EB) formation. After EB dissociation, early hematopoietic progenitors were enriched and cocultivated on OP9 feeder cells with thrombopoietin and stem cell factor to induce megakaryocyte (MK) differentiation. Results Overexpression of GATA1 and Pbx1 increased MK output 2‐ to 2.5‐fold and allowed prolonged collection of MK. Cytologic and ultrastructural analyses identified typical MK with enlarged cells, multilobulated nuclei, granule structures, and an internal membrane system. However, GATA1 and Pbx1 expression did not improve MK maturation or platelet release, although in vitro–generated platelets were functional in spreading on fibrinogen or collagen‐related peptide. Conclusion We demonstrate that the use of rtTA‐M2 transgenic iPSCs transduced with Tet‐inducible retroviral vectors allowed for gene expression at later time points during differentiation. With this strategy we could identify factors that increased in vitro MK production. ![]()
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Affiliation(s)
- Katharina Cullmann
- RG Gene Modification in Stem Cells, Division of Veterinary Medicine Paul-Ehrlich-Institut Langen Germany
| | - Magdalena Jahn
- RG Gene Modification in Stem Cells, Division of Veterinary Medicine Paul-Ehrlich-Institut Langen Germany
| | - Markus Spindler
- Institute of Experimental Biomedicine I University Hospital and Rudolf Virchow Center University of Würzburg Würzburg Germany
| | - Franziska Schenk
- RG Gene Modification in Stem Cells, Division of Veterinary Medicine Paul-Ehrlich-Institut Langen Germany
| | - Georgi Manukjan
- Institute of Experimental Biomedicine I University Hospital and Rudolf Virchow Center University of Würzburg Würzburg Germany
| | - Adele Mucci
- RG Reprogramming and Gene Therapy, Institute of Experimental Hematology, Hannover Medical School Hannover Germany.,Present address: San Raffaele Telethon Institute for Gene Therapy Milano Italy
| | - Doris Steinemann
- Department of Human Genetics Hannover Medical School Hannover Germany
| | - Klaus Boller
- Morphology, Division of Immunology Paul-Ehrlich-Institut Langen Germany
| | - Harald Schulze
- Institute of Experimental Biomedicine I University Hospital and Rudolf Virchow Center University of Würzburg Würzburg Germany
| | - Markus Bender
- Institute of Experimental Biomedicine I University Hospital and Rudolf Virchow Center University of Würzburg Würzburg Germany
| | - Thomas Moritz
- RG Reprogramming and Gene Therapy, Institute of Experimental Hematology, Hannover Medical School Hannover Germany
| | - Ute Modlich
- RG Gene Modification in Stem Cells, Division of Veterinary Medicine Paul-Ehrlich-Institut Langen Germany
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Jahn M. Chemiereaktoren - Grundlagen, Auslegung und Simulation, 2. Auflage. Von J. Hagen. CHEM-ING-TECH 2018. [DOI: 10.1002/cite.201871113] [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: 11/08/2022]
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Baumann H, Jahn M, Muenchau A, Trilck-Winkler M, Lohmann K, Seibler P. Generation and characterization of eight human-derived iPSC lines from affected and unaffected THAP1 mutation carriers. Stem Cell Res 2018; 33:60-64. [PMID: 30316041 DOI: 10.1016/j.scr.2018.09.018] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/18/2018] [Accepted: 09/26/2018] [Indexed: 11/30/2022] Open
Abstract
Mutations in THAP1 (THAP domain-containing apoptosis-associated protein 1) cause a form of early-onset, isolated dystonia (DYT-THAP1, aka DYT6). Here, we describe the generation of eight human induced pluripotent stem cell (iPSC) lines of manifesting and non-manifesting carriers of the THAP1 mutations p.Lys158Asnfs*23 or p.Arg13His (each 4 lines). Dermal fibroblasts were reprogrammed using non-integrating Sendai virus. The iPSC lines were comprehensively characterized including expression analyses of pluripotency markers, the potential to differentiate into cells of all three germ layers, and stable karyotypes. These lines provide a valuable resource for studying the impact of THAP1 mutations on the pathology of dystonia.
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Affiliation(s)
- Hauke Baumann
- Institute of Neurogenetics, University of Luebeck, Luebeck, Germany
| | - Magdalena Jahn
- Institute of Neurogenetics, University of Luebeck, Luebeck, Germany
| | | | | | - Katja Lohmann
- Institute of Neurogenetics, University of Luebeck, Luebeck, Germany
| | - Philip Seibler
- Institute of Neurogenetics, University of Luebeck, Luebeck, Germany.
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Radu AI, Ussembayev YY, Jahn M, Schubert US, Weber K, Cialla-May D, Hoeppener S, Heisterkamp A, Popp J. HD DVD substrates for surface enhanced Raman spectroscopy analysis: fabrication, theoretical predictions and practical performance. RSC Adv 2016. [DOI: 10.1039/c6ra06029c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Commercially available HD-DVD templates have been used to theoretically predict the occurrence of surface plasmons supermodes which improve the detection of surface enhanced Raman signals.
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Affiliation(s)
- A. I. Radu
- Friedrich Schiller University Jena
- Institute of Physical Chemistry and Abbe Center of Photonics
- 07745 Jena
- Germany
- Leibniz Institute of Photonic Technology Jena
| | - Ye. Ye. Ussembayev
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
| | - M. Jahn
- Friedrich Schiller University Jena
- Institute of Physical Chemistry and Abbe Center of Photonics
- 07745 Jena
- Germany
- Leibniz Institute of Photonic Technology Jena
| | - U. S. Schubert
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
| | - K. Weber
- Friedrich Schiller University Jena
- Institute of Physical Chemistry and Abbe Center of Photonics
- 07745 Jena
- Germany
- Leibniz Institute of Photonic Technology Jena
| | - D. Cialla-May
- Friedrich Schiller University Jena
- Institute of Physical Chemistry and Abbe Center of Photonics
- 07745 Jena
- Germany
- Leibniz Institute of Photonic Technology Jena
| | - S. Hoeppener
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
| | - A. Heisterkamp
- Institute of Applied Optics
- Friedrich Schiller University
- 07743 Jena
- Germany
| | - J. Popp
- Friedrich Schiller University Jena
- Institute of Physical Chemistry and Abbe Center of Photonics
- 07745 Jena
- Germany
- Leibniz Institute of Photonic Technology Jena
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Ehrmann D, Spengler M, Jahn M, Siebert H, Niebuhr D, Haak T, Kulzer B, Hermanns N. Wie häufig tragen Risikopatienten Schuhe mit diabetesadaptierter Fußbettung? DIABETOL STOFFWECHS 2015. [DOI: 10.1055/s-0035-1549649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Agyapong V, Kavanah A, Shandalla L, Ogunsina O, Jahn M, Ambrosano L, Corbett S. Factors Predicting the Likelihood of Referral of Liaison Psychiatric Patients Assessed by Crisis Nurses in the Emergency Room to a Psychiatrist for Follow-up. Eur Psychiatry 2015. [DOI: 10.1016/s0924-9338(15)30279-0] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Ditter R, Haspel M, Jahn M, Kollar I, Siegmund A, Viehrig K, Volz D, Siegmund A. Geospatial technologies in school - theoretical concept and practical implementation in K-12 schools. IJDMMM 2015. [DOI: 10.1504/ijdmmm.2015.067631] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Hidi IJ, Jahn M, Weber K, Cialla-May D, Popp J. Droplet based microfluidics: spectroscopic characterization of levofloxacin and its SERS detection. Phys Chem Chem Phys 2015; 17:21236-42. [DOI: 10.1039/c4cp04970e] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The determination of the absorption behavior of levofloxacin (levaquin) on the surface of silver nanoparticles and its determination in aqueous solution by droplet based microfluidics combined with surface enhanced Raman spectroscopy.
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Affiliation(s)
- I. J. Hidi
- Friedrich Schiller University Jena
- Institute of Physical Chemistry and Abbe Center of Photonics
- 07745 Jena
- Germany
| | - M. Jahn
- Friedrich Schiller University Jena
- Institute of Physical Chemistry and Abbe Center of Photonics
- 07745 Jena
- Germany
| | - K. Weber
- Friedrich Schiller University Jena
- Institute of Physical Chemistry and Abbe Center of Photonics
- 07745 Jena
- Germany
- Leibniz Institute of Photonic Technology Jena
| | - D. Cialla-May
- Friedrich Schiller University Jena
- Institute of Physical Chemistry and Abbe Center of Photonics
- 07745 Jena
- Germany
- Leibniz Institute of Photonic Technology Jena
| | - J. Popp
- Friedrich Schiller University Jena
- Institute of Physical Chemistry and Abbe Center of Photonics
- 07745 Jena
- Germany
- Leibniz Institute of Photonic Technology Jena
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Speiser D, Jahn M, Lanowska M, Mangler M, Ingold-Heppner B. Expression von Zellzyklusregulatoren und ki67 bei Patientinnen mit Rezidiv nach radikaler vaginaler Trachelektomie (RVT). Geburtshilfe Frauenheilkd 2014. [DOI: 10.1055/s-0034-1388482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Ehrmann D, Siebert H, Spengler N, Jahn M, Niebuhr D, Kulzer B, Haak T, Hermanns N. Diabetesadaptierte Schuhversorgung: Erfassung der Patientenzufriedenheit zur Charakterisierung des patientenrelevanten Nutzens. DIABETOL STOFFWECHS 2014. [DOI: 10.1055/s-0034-1374944] [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: 10/25/2022]
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Tudorie M, Kleiner I, Jahn M, Grabow JU, Goubet M, Pirali O. Coupled Large Amplitude Motions: A Case Study of the Dimethylbenzaldehyde Isomers. J Phys Chem A 2013; 117:13636-47. [DOI: 10.1021/jp407603y] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M Tudorie
- Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR 7583 CNRS/IPSL, Universités Paris-Est et Paris Diderot , 61 avenue du Général de Gaulle, 94010 Créteil Cedex, France
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Jahn M, Zierbock S, Cialla D, Weber K, Popp J. Bottom-up nanostructured metallic surfaces for SERS detection of low-molecular weight substances. BIOMED ENG-BIOMED TE 2012. [DOI: 10.1515/bmt-2012-4094] [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: 11/15/2022]
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Jahn M, Radchenko V, Filosofov DV, Hauser H, Eisenhut M, Rösch F, Jennewein M. Separation and purification of no-carrier-added arsenic from bulk amounts of germanium for use in radiopharmaceutical labelling. RADIOCHIM ACTA 2010. [DOI: 10.1524/ract.2010.1783] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
Radioarsenic labelled radiopharmaceuticals could add special features to molecular imaging with positron emission tomography (PET). For example the long physical half-lives of 72As (T
1/2=26 h) and 74As (T
1/2=17.8 d) in conjunction with their high positron branching rates of 88% and 29%, respectively, allow the investigation of slow physiological or metabolical processes, like the enrichment and biodistribution of monoclonal antibodies in tumour tissue or the characterization of stem cell trafficking. A method for separation and purification of no-carrier-added (nca) arsenic from irradiated metallic germanium targets based on distillation and anion exchange is developed. It finally converts the arsenic into an *As(III) synthon in PBS buffer and pH 7 suitable for labelling of proteins via As-S bond formations. The method delivers radioarsenic in high purity with separation factors of 106 from germanium and an overall yield from target to labelling synthon of >40%. In a proof-of-principle experiment, the monoclonal antibody Bevacizumab, directed against the human VEGF receptor, was labelled with a radiochemical yield >90% within 1 h at room temperature with nca 72/74/77As.
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Affiliation(s)
- M. Jahn
- Johannes-Gutenberg-University of Mainz, Institute of Nuclear Chemistry, Mainz
| | - V. Radchenko
- Johannes-Gutenberg-University of Mainz, Institute of Nuclear Chemistry, Mainz, Deutschland
| | - D. V. Filosofov
- Joint Institute of Nuclear Research, Laboratory of Nuclear Problems, Dubna, Russische Föderation
| | - H. Hauser
- German Cancer Research Center, Radiopharmaceutical Chemistry, Heidelberg
| | - M. Eisenhut
- German Cancer Research Center, Radiopharmaceutical Chemistry, Heidelberg
| | | | - M. Jennewein
- Johannes Gutenberg University, Institute for Nuclear Chemistry, Mainz, Deutschland
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Jahn M, Michaelis A, Pohl M, Schreck C. Schaumkeramik als Katalysatorsystem. CHEM-ING-TECH 2010. [DOI: 10.1002/cite.201050545] [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: 11/11/2022]
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Marschallek F, Adler J, Böttge D, Füssel A, Jahn M, Michaelis A. Verbrennung in porösem SiC: Beiträge zu Prozessabsicherung und Dauerstabilität. CHEM-ING-TECH 2010. [DOI: 10.1002/cite.201050524] [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: 11/11/2022]
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Röder O, Jahn M, Schröder T, Stahl M, Kotte M, Beuermann S. Die e-ventus Technologie – eine Innovation zur nachhaltigen Reduktion von Pflanzenschutzmitteln mit Empfehlung für Bio-Saatgut. J Verbrauch Lebensm 2009. [DOI: 10.1007/s00003-009-0476-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Heddrich MP, Jahn M, Marschallek F, Näke R, Stelter M. Entwicklung, Aufbau und Betrieb eines Brennstoffzellensystems für Biogas. CHEM-ING-TECH 2008. [DOI: 10.1002/cite.200750677] [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: 11/06/2022]
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Marschallek F, Adler J, Belitz R, Böttge D, Heddrich M, Jahn M. Mehrstofffähige Brenner für den Einsatz in Brennstoffzellensystemen. CHEM-ING-TECH 2008. [DOI: 10.1002/cite.200750682] [Citation(s) in RCA: 2] [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: 11/10/2022]
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Jennewein M, Qaim SM, Hermanne A, Jahn M, Tsyganov E, Slavine N, Seliounine S, Antich PA, Kulkarni PV, Thorpe PE, Mason RP, Rösch F. A new method for radiochemical separation of arsenic from irradiated germanium oxide. Appl Radiat Isot 2005; 63:343-51. [PMID: 15955705 DOI: 10.1016/j.apradiso.2005.04.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2005] [Revised: 04/04/2005] [Accepted: 04/13/2005] [Indexed: 11/30/2022]
Abstract
Radioarsenic labelled radiopharmaceuticals could be a valuable asset to Positron Emission Tomography (PET). In particular, the long half-lives of (72)As (T(1/2)=26 h) and (74)As (T(1/2)=17.8 d) allow to investigate slow physiological or metabolical processes, like the enrichment and distribution of antibodies in tumor tissue. This work describes the direct production of no-carrier-added (nca) arsenic isotopes *As, with *=71, 72, 73, 74 or 77, the reaction to [*As]AsI(3) and its radiochemical separation from the irradiated solid germanium oxide via polystyrene-based solid-phase extraction. The germanium oxide target, irradiated at a cyclotron or a nuclear reactor, is dissolved in concentrated HF and Ge is separated almost quantitatively (99.97%) as [GeF(6)](2-). [*As]AsI(3) is formed by addition of potassium iodide. The radiochemical separation yield for arsenic is >90%. [*As]AsI(3) is a versatile radioarsenic labelling synthon.
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Affiliation(s)
- M Jennewein
- Institute of Nuclear Chemistry, Johannes Gutenberg University of Mainz, Fritz-Strassmann-Weg 2, 55128 Mainz, Germany
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Zhernosekov K, Aschoff P, Filosofov D, Jahn M, Jennewein M, Adrian HJ, Bihl H, Rösch F. Visualisation of a somatostatin receptor-expressing tumour with 67Ga-DOTATOC SPECT. Eur J Nucl Med Mol Imaging 2005; 32:1129. [PMID: 16133389 DOI: 10.1007/s00259-005-1864-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- K Zhernosekov
- Institut für Kernchemie, Universität Mainz, Mainz, Germany.
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Li Z, Gulyas H, Jahn M, Gajurel DR, Otterpohl R. Greywater treatment by constructed wetlands in combination with TiO2-based photocatalytic oxidation for suburban and rural areas without sewer system. Water Sci Technol 2003; 48:101-106. [PMID: 14753524] [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: 05/24/2023]
Abstract
In this study greywater treatment through constructed wetlands and subsequently through TiO2-based photocatalytic oxidation was investigated. Through constructed wetlands treatment the organic substances have been reduced greatly. For further removal of organic substances and pathogens, a TiO2-based photocatalytic oxidation process was used subsequently. The results showed that the treated greywater through constructed wetlands and subsequent through TiO2-based photocatalytic oxidation with short irradiation time (3 hours irradiation time) met the requirements of European bathing water quality easily. Therefore, the greywater treated with the processes combination can directly be reused for non-potable purposes. Moreover, since residual organic substances through TiO2-based photocatalytic oxidation with long irradiation time can be eliminated almost totally, it is also possible that treated greywater is used for groundwater recharge as a drinking water resource.
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Affiliation(s)
- Z Li
- Technical University of Hamburg Harburg, Institute of Municipal and Industrial Wastewater Management, D-21073 Hamburg, Germany.
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Van Cutsem E, Twelves C, Cassidy J, Allman D, Bajetta E, Boyer M, Bugat R, Findlay M, Frings S, Jahn M, McKendrick J, Osterwalder B, Perez-Manga G, Rosso R, Rougier P, Schmiegel WH, Seitz JF, Thompson P, Vieitez JM, Weitzel C, Harper P. Oral capecitabine compared with intravenous fluorouracil plus leucovorin in patients with metastatic colorectal cancer: results of a large phase III study. J Clin Oncol 2001; 19:4097-106. [PMID: 11689577 DOI: 10.1200/jco.2001.19.21.4097] [Citation(s) in RCA: 793] [Impact Index Per Article: 34.5] [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: 12/20/2022] Open
Abstract
PURPOSE To compare the efficacy and safety of orally administered capecitabine (Xeloda; Roche Laboratories, Inc, Nutley, NJ), a novel fluoropyrimidine carbamate designed to mimic continuous fluorouracil (5-FU) infusion but with preferential activation at the tumor site, with that of intravenous (IV) 5-FU plus leucovorin (5-FU/LV) as first-line treatment for metastatic colorectal cancer. PATIENTS AND METHODS We prospectively randomized 602 patients to treatment with capecitabine 1,250 mg/m(2) administered twice daily days 1 to 14 every 3 weeks, or to the 4-weekly Mayo Clinic regimen (5-FU/LV) until disease progression or unacceptable toxicity. RESULTS The primary objective, to demonstrate at least equivalent response rates in the two treatment groups, was met. The overall response rate was 18.9% for capecitabine and 15.0% for 5-FU/LV. In the capecitabine and 5-FU/LV groups, respectively, median time to disease progression was 5.2 and 4.7 months (log-rank P =.65); median time to treatment failure was 4.2 and 4.0 months (log-rank P =.89); and median overall survival was 13.2 and 12.1 months (log-rank P =.33). The toxicity profiles of both treatments were typical of fluoropyrimidines. However, capecitabine led to significantly lower incidences (P <.00001) of stomatitis and alopecia, but a higher incidence of cutaneous hand-foot syndrome (P <.00001). Capecitabine also resulted in lower incidences (P <.00001) of grade 3/4 stomatitis and neutropenia, leading to a lower incidence of grade 3/4 neutropenic fever and sepsis. Only grade 3 hand-foot syndrome (P <.00001) and uncomplicated grade 3/4 hyperbilirubinemia (P <.0001) were reported more frequently with capecitabine. CONCLUSION Oral capecitabine achieved an at least equivalent efficacy compared with IV 5-FU/LV. Capecitabine demonstrated clinically meaningful safety advantages and the convenience of an oral agent.
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Affiliation(s)
- E Van Cutsem
- Department of Internal Medicine, University Hospital Gasthuisberg, Leuven, Belgium.
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Schühle K, Jahn M, Ghisla S, Fuchs G. Two similar gene clusters coding for enzymes of a new type of aerobic 2-aminobenzoate (anthranilate) metabolism in the bacterium Azoarcus evansii. J Bacteriol 2001; 183:5268-78. [PMID: 11514509 PMCID: PMC95408 DOI: 10.1128/jb.183.18.5268-5278.2001] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the beta-proteobacterium Azoarcus evansii, the aerobic metabolism of 2-aminobenzoate (anthranilate), phenylacetate, and benzoate proceeds via three unprecedented pathways. The pathways have in common that all three substrates are initially activated to coenzyme A (CoA) thioesters and further processed in this form. The two initial steps of 2-aminobenzoate metabolism are catalyzed by a 2-aminobenzoate-CoA ligase forming 2-aminobenzoyl-CoA and by a 2-aminobenzoyl-CoA monooxygenase/reductase (ACMR) forming 2-amino-5-oxo-cyclohex-1-ene-1-carbonyl-CoA. Eight genes possibly involved in this pathway, including the genes encoding 2-aminobenzoate-CoA ligase and ACMR, were detected, cloned, and sequenced. The sequence of the ACMR gene showed that this enzyme is an 87-kDa fusion protein of two flavoproteins, a monooxygenase (similar to salicylate monooxygenase) and a reductase (similar to old yellow enzyme). Besides the genes for the initial two enzymes, genes for three enzymes of a beta-oxidation pathway were found. A substrate binding protein of an ABC transport system, a MarR-like regulator, and a putative translation inhibitor protein were also encoded by the gene cluster. The data suggest that, after monooxygenation/reduction of 2-aminobenzoyl-CoA, the nonaromatic CoA thioester intermediate is metabolized further by beta-oxidation. This implies that all subsequent intermediates are CoA thioesters and that the alicyclic carbon ring is not cleaved oxygenolytically. Surprisingly, the cluster of eight genes, which form an operon, is duplicated. The two copies differ only marginally within the coding regions but differ substantially in the respective intergenic regions. Both copies of the genes are coordinately expressed in cells grown aerobically on 2-aminobenzoate.
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Affiliation(s)
- K Schühle
- Mikrobiologie, Institut für Biologie II, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
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Piert M, Zittel TT, Becker GA, Jahn M, Stahlschmidt A, Maier G, Machulla HJ, Bares R. Assessment of porcine bone metabolism by dynamic. J Nucl Med 2001; 42:1091-100. [PMID: 11438633] [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: 02/20/2023] Open
Abstract
UNLABELLED The aim of this study was to quantify regional bone blood flow and [(18)F]fluoride ion influx with [(18)F]fluoride ion PET and correlate the results with specific static and dynamic indices of bone metabolism in healthy pigs. METHODS During continuous ventilation (fractional concentration of oxygen in inspired gas = 0.3), dynamic PET scans 120 min in duration were obtained for 9 mini pigs after intravenous injection of 10.0 +/- 1.2 MBq (mean +/- SD) of [(18)F]fluoride ion per kilogram of body weight. Iliac crest bone biopsies were performed immediately before the PET scan to determine static and dynamic indices of bone metabolism (i.e., the mineral apposition rate) by bone histomorphometry. Kinetic rate constants describing influx (K(1)) and efflux (k(2)) of [(18)F]fluoride as well as chemisorption and incorporation of [(18)F]fluoride (k(3)) and reverse transport (k(4)) were determined for 6 vertebral bodies in each animal. Blood flow estimates (f) were derived from K(1) values corrected for the permeability-surface area product using a previously derived correction algorithm. A rate constant describing the net forward transport rate of fluoride (K(i)) and the fluoride volume flux (K(flux)) derived from a 2-tissue-compartment model was calculated and compared with the results of Patlak graphic analysis (K(pat)). RESULTS A significant correlation was found between mineral apposition rate and K(i) (P < 0.005), K(flux) (P < 0.01), K(pat), K(1), and f (P < 0.05). The values of f, K(i), K(flux), and K(pat) did not correlate significantly with other static or dynamic histomorphometric indices or with age, serum alkaline phosphatase, or parathyroid hormone levels. The values of f and K(i) correlated linearly (y = 0.023 + 0.32x; r(2) = 0.74; P < 0.001). CONCLUSION PET bone studies using [(18)F]fluoride ion provide quantitative estimates of bone blood flow and metabolic activity that correlate with histomorphometric indices of bone formation in the normal bone tissue of the mini pig. Therefore, it seem reasonable to assume that [(18)F]fluoride ion PET can reduce the number of invasive bone biopsies, thus facilitating follow-up of patients with metabolic bone diseases.
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Affiliation(s)
- M Piert
- Department of General Surgery, University of Tübingen, Tübingen, Germany
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Abstract
The anaerobic metabolism of 3-hydroxybenzoate was studied in the denitrifying bacterium Thauera aromatica. Cells grown with this substrate were adapted to grow with benzoate but not with 4-hydroxybenzoate. Vice versa, 4-hydroxybenzoate-grown cells did not utilize 3-hydroxybenzoate. The first step in 3-hydroxybenzoate metabolism is a coenzyme A (CoA) thioester formation, which is catalyzed by an inducible 3-hydroxybenzoate-CoA ligase. The enzyme was purified and characterized. Further metabolism of 3-hydroxybenzoyl-CoA by cell extract required MgATP and was coupled to the oxidation of 2 mol of reduced viologen dyes per mol of substrate added. Purification of the 3-hydroxybenzoyl-CoA reducing enzyme revealed that this activity was due to benzoyl-CoA reductase, which reduced the 3-hydroxy analogue almost as efficiently as benzoyl-CoA. The further metabolism of the alicyclic dienoyl-CoA product containing the hydroxyl substitution obviously required additional specific enzymes. Comparison of the protein pattern of 3-hydroxybenzoate-grown cells with benzoate-grown cells revealed several 3-hydroxybenzoate-induced proteins; the N-terminal amino acid sequences of four induced proteins were determined and the corresponding genes were identified and sequenced. A cluster of six adjacent genes contained the genes for substrate-induced proteins 1 to 3; this cluster may not yet be complete. Protein 1 is a short-chain alcohol dehydrogenase. Protein 2 is a member of enoyl-CoA hydratase enzymes. Protein 3 was identified as 3-hydroxybenzoate-CoA ligase. Protein 4 is another member of the enoyl-CoA hydratases. In addition, three genes coding for enzymes of beta-oxidation were present. The anaerobic 3-hydroxybenzoate metabolism here obviously combines an enzyme (benzoyl-CoA reductase) and electron carrier (ferredoxin) of the general benzoyl-CoA pathway with enzymes specific for the 3-hydroxybenzoate pathway. This raises some questions concerning the regulation of both pathways.
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Affiliation(s)
- D Laempe
- Mikrobiologie, Institut für Biologie II, Albert-Ludwigs-Universität, Freiburg, Germany
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Collmer CW, Marston MF, Taylor JC, Jahn M. The I gene of bean: a dosage-dependent allele conferring extreme resistance, hypersensitive resistance, or spreading vascular necrosis in response to the potyvirus Bean common mosaic virus. Mol Plant Microbe Interact 2000; 13:1266-1270. [PMID: 11059494 DOI: 10.1094/mpmi.2000.13.11.1266] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The resistance to the potyvirus Bean common mosaic virus (BCMV) conferred by the I allele in cultivars of Phaseolus vulgaris has been characterized as dominant, and it has been associated with both immunity and a systemic vascular necrosis in infected bean plants under field, as well as controlled, conditions. In our attempts to understand more fully the nature of the interaction between bean with the I resistance allele and the pathogen BCMV, we carefully varied both I allele dosage and temperature and observed the resulting, varying resistance responses. We report here that the I allele in the bean cultivars we studied is not dominant, but rather incompletely dominant, and that the system can be manipulated to show in plants a continuum of response to BCMV that ranges from immunity or extreme resistance, to hypersensitive resistance, to systemic phloem necrosis (and subsequent plant death). We propose that the particular phenotypic outcome in bean results from a quantitative interaction between viral pathogen and plant host that can be altered to favor one or the other by manipulating I allele dosage, temperature, viral pathogen, or plant cultivar.
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Affiliation(s)
- C W Collmer
- Department of Biological and Chemical Sciences, Wells College, Aurora, NY 13026, USA.
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Thorup TA, Tanyolac B, Livingstone KD, Popovsky S, Paran I, Jahn M. Candidate gene analysis of organ pigmentation loci in the Solanaceae. Proc Natl Acad Sci U S A 2000; 97:11192-7. [PMID: 11027328 PMCID: PMC17176 DOI: 10.1073/pnas.97.21.11192] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [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: 11/18/2022] Open
Abstract
Ten structural genes from the Capsicum (pepper) carotenoid biosynthetic pathway have been localized on a (Capsicum annuum x Capsicum chinense)F(2) genetic map anchored in Lycopersicon (tomato). The positions of these genes were compared with positions of the same genes in tomato when known, and with loci from pepper, potato, and tomato that affect carotenoid levels in different tissues. C2, one of three phenotypically defined loci determining pepper fruit color, cosegregated with phytoene synthase. The capsanthin-capsorubin synthase (Ccs) locus, shown previously to cosegregate with Y, another pepper fruit color locus, mapped to pepper chromosome 6. Other structural genes in pepper corresponded to loci affecting carotenoid production as follows: Ccs in pepper and the B locus for hyperaccumulation of beta-carotene in tomato fruit mapped to homeologous regions; the position of the lycopene beta-cyclase gene in pepper may correspond to the lutescent-2 mutation in tomato; and the lycopene epsilon-cyclase locus in pepper corresponded to the lycopene epsilon-cyclase locus/Del mutation for hyperaccumulation of delta-carotene in tomato fruit. Additional associations were seen between the structural genes and previously mapped loci controlling quantitative variation in pepper and tomato fruit color. These results demonstrate that comparative analyses using candidate genes may be used to link specific metabolic phenotypes and loci that affect these phenotypes in related species.
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Affiliation(s)
- T A Thorup
- Department of Plant Breeding, Cornell University, Ithaca, NY 14853; and Department of Plant Genetics and Breeding, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel
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Jahn M, Paran I, Hoffmann K, Radwanski ER, Livingstone KD, Grube RC, Aftergoot E, Lapidot M, Moyer J. Genetic mapping of the Tsw locus for resistance to the Tospovirus Tomato spotted wilt virus in Capsicum spp. and its relationship to the Sw-5 gene for resistance to the same pathogen in tomato. Mol Plant Microbe Interact 2000; 13:673-682. [PMID: 10830267 DOI: 10.1094/mpmi.2000.13.6.673] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The Tsw gene conferring dominant resistance to the Tospovirus Tomato spotted wilt virus (TSWV) in Capsicum spp. has been tagged with a random amplified polymorphic DNA marker and mapped to the distal portion of chromosome 10. No mapped homologues of Sw-5, a phenotypically similar dominant TSWV resistance gene in tomato, map to this region in C. annuum, although a number of Sw-5 homologues are found at corresponding positions in pepper and tomato. The relationship between Tsw and Sw-5 was also examined through genetic studies of TSWV. The capacity of TSWV-A to overcome the Tsw gene in pepper and the Sw-5 gene in tomato maps to different TSWV genome segments. Therefore, despite phenotypic and genetic similarities of resistance in tomato and pepper, we infer that distinct viral gene products control the outcome of infection in plants carrying Sw-5 and Tsw, and that these loci do not appear to share a recent common evolutionary ancestor.
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Affiliation(s)
- M Jahn
- Department of Plant Breeding, Cornell University, Ithaca, NY 14853, USA
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Abstract
Genomic positions of phenotypically defined disease resistance genes (R genes) and R gene homologues were analyzed in three solanaceous crop genera, Lycopersicon (tomato), Solanum (potato), and Capsicum (pepper). R genes occurred at corresponding positions in two or more genomes more frequently than expected by chance; however, in only two cases, both involving Phytophthora spp., did genes at corresponding positions have specificity for closely related pathogen taxa. In contrast, resistances to Globodera spp., potato virus Y, tobacco mosaic virus, and tomato spotted wilt virus were mapped in two or more genera and did not occur in corresponding positions. Without exception, pepper homologues of the cloned R genes Sw-5, N, Pto, Prf, and I2 were found in syntenous positions in other solanaceous genomes and in some cases also mapped to additional positions near phenotypically defined solanaceous R genes. This detailed analysis and synthesis of all available data for solanaceous R genes suggests a working hypothesis regarding the evolution of R genes. Specifically, while the taxonomic specificity of host R genes may be evolving rapidly, general functions of R alleles (e.g., initiation of resistance response) may be conserved at homologous loci in related plant genera.
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Affiliation(s)
- R C Grube
- Department of Plant Breeding, Cornell University, Ithaca, New York 14853, USA
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Jahn M, Baynes JW, Spiteller G. The reaction of hyaluronic acid and its monomers, glucuronic acid and N-acetylglucosamine, with reactive oxygen species. Carbohydr Res 1999; 321:228-34. [PMID: 10614067 DOI: 10.1016/s0008-6215(99)00186-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [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: 11/24/2022]
Abstract
Synovial fluid is a approximately 0.15% (w/v) aqueous solution of hyaluronic acid (HA), a polysaccharide consisting of alternating units of GlcA and GlcNAc. In synovial fluid of patients suffering from rheumatoid arthritis, HA is thought to be degraded either by radicals generated by Fenton chemistry (Fe2+/H2O2) or by NaOCl generated by myeloperoxidase. We investigated the course of model reactions of these two reactants in physiological buffer with HA, and with the corresponding monomers GlcA and GlcNAc. meso-Tartaric acid, arabinuronic acid, arabinaric acid and glucaric acid were identified by GC-MS as oxidation products of glucuronic acid. When GlcNAc was oxidised, erythronic acid, arabinonic acid, 2-acetamido-2-deoxy-gluconic acid, glyceric acid, erythrose and arabinose were formed. NaOCl oxidation of HA yielded meso-tartaric acid; in addition, arabinaric acid and glucaric acid were obtained by oxidation with Fe2+/H2O2. These results indicate that oxidative degradation of HA proceeds primarily at glucuronic acid residues. meso-Tartaric acid may be a useful biomarker of hyaluronate oxidation since it is produced by both NaOCl and Fenton chemistry.
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Affiliation(s)
- M Jahn
- Lehrstuhl Organische Chemie I, Universität Bayreuth, Germany
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Laempe D, Jahn M, Fuchs G. 6-Hydroxycyclohex-1-ene-1-carbonyl-CoA dehydrogenase and 6-oxocyclohex-1-ene-1-carbonyl-CoA hydrolase, enzymes of the benzoyl-CoA pathway of anaerobic aromatic metabolism in the denitrifying bacterium Thauera aromatica. Eur J Biochem 1999; 263:420-9. [PMID: 10406950 DOI: 10.1046/j.1432-1327.1999.00504.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Benzoyl-CoA is a common intermediate in the anaerobic bacterial metabolism of many aromatic substrates. Two enzymes and ferredoxin of the central benzoyl-CoA pathway in Thauera aromatica have been purified so far. Benzoyl-CoA reductase reduces the aromatic ring with reduced ferredoxin yielding cyclohexa-1,5-diene-1-carbonyl-CoA [Boll, M. & Fuchs, G. (1995) Eur. J. Biochem. 234, 921-933]. Dienoyl-CoA hydratase subsequently adds one molecule of water and thereby produces 6-hydroxycyclohex-1-ene-1-carbonyl-CoA [Laempe, D., Eisenreich, W., Bacher, A., & Fuchs, G. (1998) Eur. J. Biochem. 255, 618-627]. Here two new enzymes, which convert this intermediate to the noncyclic product 3-hydroxypimelyl-CoA, were purified from T. aromatica and studied. 6-Hydroxycyclohex-1-ene-1-carbonyl-CoA dehydrogenase is an NAD(+)-specific beta-hydroxyacyl-CoA dehydrogenase that catalyzes 6-hydroxycyclohex-1-ene-1-carbonyl-CoA + NAD(+) --> 6-oxocyclohex-1-ene-1-carbonyl-CoA + NADH + H(+). 6-Oxocyclohex-1-ene-1-carbonyl-CoA hydrolase acts on the beta-oxoacyl-CoA compound and catalyzes the addition of one molecule of water to the double bound and the hydrolytic C-C cleavage of the alicyclic ring, 6-oxocyclohex-1-ene-1-carbonyl-CoA + 2 H(2)O --> 3-hydroxypimelyl-CoA. The genes for both enzymes, had and oah, were cloned, had was overexpressed in Escherichia coli and the recombinant protein was purified. Hence, presumably all enzymes of the central benzoyl-CoA pathway of anaerobic aromatic metabolism from this organism have now been purified and studied and the corresponding genes have been cloned and sequenced.
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Affiliation(s)
- D Laempe
- Mikrobiologie, Institut Biologie II, Universität Freiburg, Freiburg, Germany
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Abstract
OBJECTIVE The aim of the study was to examine whether the neuromuscular blocking potency of atracurium changes in patients with a septic intrathoracic process. DESIGN Prospective clinical study. SETTING Community hospital. PARTICIPANTS Thirty patients who underwent thoracic surgery for resection of a pulmonary carcinoma were examined. Fifteen patients showed typical signs of a concomitant bacterial superinfection (infection group), 15 age-matched patients without infection served as the control (no-infection) group. INTERVENTIONS Relaxation was induced with atracurium, 0.6 mg/kg intravenously for intubation, followed by a continuous infusion to maintain a 90% neuromuscular blockade. Relaxometry was performed electromyographically using the Datex Relaxograph by stimulating the ulnar nerve next to the wrist. MEASUREMENTS AND MAIN RESULTS The onset time was significantly longer (5.3 +/- 2.9 v 3.3 +/- 1.2 minutes; p < 0.05), and the recovery phase (DUR 10%) was significantly shorter (23.5 +/- 8.6 v 36.9 +/- 7.3 minutes; p < 0.001) in the infection group compared with the controls. The infusion rate within the first hour of continuous application was 77.4% higher in the infection group than in the control group (11.0 +/- 2.9 v 6.2 +/- 1.0 microg/kg/min; p < 0.001). CONCLUSION The study showed that septic intrathoracic processes cause a clear reduction of the neuromuscular blocking potency of atracurium. To guarantee adequate muscle relaxation in such cases, precise neuromuscular monitoring is highly advisable.
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Affiliation(s)
- D Knüttgen
- Department of Anesthesia, Municipal Clinics of Cologne, Germany
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Piert M, Zittel TT, Machulla HJ, Becker GA, Jahn M, Maier G, Bares R, Becker HD. Blood flow measurements with [(15)O]H2O and [18F]fluoride ion PET in porcine vertebrae. J Bone Miner Res 1998; 13:1328-36. [PMID: 9718202 DOI: 10.1359/jbmr.1998.13.8.1328] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A dual positron emission tomography (PET) tracer study with [18F]fluoride and the freely diffusible tracer [(15)O]H2O was performed to measure the capillary transport of [18F]fluoride and to evaluate the potential of [18F]fluoride ion PET to quantitate bone blood flow. Under the condition of a high predictable single-pass extraction fraction (E(F)) for [18F]fluoride, the [18F]fluoride ion influx transport constant (K1F), derived from kinetic [18F]fluoride ion PET measurements, can be used to estimate bone blood flow. Bone blood flow was measured in vertebral bodies by dynamic [(15)O]H2O PET during continuous ventilation with N2O, O2, and Isoflurane (FiO2 = 0.3) in seven adult mini pigs, followed by dynamic [18F]fluoride ion PET. The mean blood flow measured by [(15)O]H2O (FlowH2O) was 0.145 +/- 0.047 ml x minute(-1) x ml(-1) and the mean K1F was 0.118 +/- 0.031 ml x minute(-1) x ml(-1), respectively (mean +/- SD). Regional analysis showed excellent agreement between FlowH2O and K1F at low flow and a significant underestimation of flow by K1F relative to FlowH2O in regions of normal and elevated flow. The observed relationship between parameters followed the Renkin-Crone distribution. The permeability-surface product was determined as 0.25 minute(-1) for vertebral bodies consisting of a mixture of trabecular and cortical bone. We conclude that [18F]fluoride ion PET can be used to estimate bone blood flow in low and normal flow regions, as long as the flow dependency of the E(F) is taken into consideration. Above blood flow values of 0.2 to 0.35 ml x minute(-1) x ml(-1), the magnitude of K1F is increasingly independent on blood flow because diffusion limits tracer transport.
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Affiliation(s)
- M Piert
- Department of General Surgery, University of Tübingen, Germany
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Jahn M. National Medical Laboratory Week. Silly games and serious science mix. MLO Med Lab Obs 1998; 30:28-9. [PMID: 10178600] [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: 02/11/2023]
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Besimo C, Gächter M, Jahn M, Hassell T. Clinical performance of resin-bonded fixed partial dentures and extracoronal attachments for removable prostheses. J Prosthet Dent 1997; 78:465-71. [PMID: 9399188 DOI: 10.1016/s0022-3913(97)70061-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
STATEMENT OF PROBLEM It is important to evaluate the long-term clinical performance of resin-bonded fixed partial dentures and extracoronal attachments for removable prostheses. PURPOSE A prospective, long-term clinical study was conducted to evaluate the success of resin-bonded fixed partial dentures since 1985 and of resin-bonded extracoronal attachments from 1987. METHODS Until 1993, a total of 130 resin-bonded fixed partial dentures had been seated in 101 patients, as well as 12 removable partial dentures (RPDs) with 24 extracoronal retainers in 10 patients. The clinical treatment protocol and the laboratory procedures were standardized. By the end of 1993, it was possible to reexamine 98 patients with a total of 127 resin-bonded fixed partial dentures and all 10 patients with removable partial dentures. The average time in function for the resin-bonded fixed partial dentures at the time of examination was 3.4 years and 2.3 years for the removable restorations. RESULTS During the period of observation, one retainer failed on six of the resin-bonded fixed partial dentures, which represents a failure rate of 4.7%. Debonding of extracoronal attachments was recorded for 8.3% of the total number of retainers. CONCLUSION The resin-bonded fixed partial denture technique can be considered to be a clinically reliable method of treatment, and permits the expansion of indications beyond a classical three-unit resin-bonded fixed partial denture. Long-term clinical success of removable partial dentures with resin-bonded extracoronal retainers warrants additional clinical studies.
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Affiliation(s)
- C Besimo
- Department of Prosthodontics, School of Dentistry, University of Basel, Switzerland
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Möbus E, Jahn M, Schmid R, Jahn D, Maser E. Testosterone-regulated expression of enzymes involved in steroid and aromatic hydrocarbon catabolism in Comamonas testosteroni. J Bacteriol 1997; 179:5951-5. [PMID: 9294458 PMCID: PMC179490 DOI: 10.1128/jb.179.18.5951-5955.1997] [Citation(s) in RCA: 53] [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: 02/05/2023] Open
Abstract
The effect of testosterone as the sole carbon source on protein expression was analyzed in Comamonas testosteroni. Testosterone simultaneously induced the expression of steroid- and aromatic hydrocarbon-catabolizing enzymes and repressed one amino acid-degrading enzyme. It is suggested that steroids play a regulative role in catabolic enzyme synthesis during adaptive growth of C. testosteroni.
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Affiliation(s)
- E Möbus
- Department of Pharmacology and Toxicology, Philipps University, Marburg, Germany
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Jahn M. You don't have to miss out on a valuable profit center. Case studies and success stories of thriving POLs. MLO Med Lab Obs 1997; 29:26, 28, 32. [PMID: 10170106] [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: 02/11/2023]
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Jahn M. The physicians' view of the lab, Part 2. Doctors speak their minds on lab profiles and problems. MLO Med Lab Obs 1997; 29:32, 34, 36-8. [PMID: 10173035] [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: 02/11/2023]
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Jahn M. POLs with profits, Part 1. Are you missing out on a valuable profit center? MLO Med Lab Obs 1997; 29:20, 58. [PMID: 10167463] [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: 02/11/2023]
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Jahn M. The physicians' view of the lab, Part 1. Clinicians examine the lab, and they like what they see. MLO Med Lab Obs 1997; 29:26-7, 30, 32-4. [PMID: 10172980] [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: 02/11/2023]
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Jahn M. 10 rules for leaving a group to go solo. Med Econ 1997; 74:141-2, 145-8, 154-5. [PMID: 10165490] [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: 02/11/2023]
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Knüttgen D, zur Nieden K, Müller-Gorges MR, Jahn M, Doehn M. Computer aided analysis of heart rate variability in brain death. Int J Clin Monit Comput 1997; 14:37-42. [PMID: 9127783 DOI: 10.1007/bf03356577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Forty neurosurgical, artificially ventilated patients were examined. Twenty of them had been diagnosed as brain dead, while twenty non-brain-dead patients served as a control group. From a surface ECG taken over a period of five minutes the mean heart rate and various indices of heart rate variability (HRV) were determined with the help of a special computer program (ProSciCard, Medisyt, Germany). The heart rate of the brain dead was significantly higher than that of the control patients. By contrast, all parameters of HRV were drastically reduced in the brain dead individuals compared to the controls. The results show that a significant change in the course of heart rate occurs after manifestation of brain death. This would appear to be the result of the elimination of all vegetative impulses derived from the brainstem. Computer-aided, the changes can be quantified in a simple way. The method could therefore be useful in brain death diagnosis.
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Affiliation(s)
- D Knüttgen
- Department of Anesthesiology, Kliniken der Stadt Köln, Cologne, Germany
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