@article{BrandAmannMandeletal.2014,
  author    = {Brand, Susanne and Amann, Kerstin and Mandel, Philipp and Zimnol, Anna and Schupp, Nicole},
  title     = {Oxidative DNA Damage in Kidneys and Heart of Hypertensive Mice Is Prevented by Blocking Angiotensin II and Aldosterone Receptors},
  series = {PLOS ONE},
  volume    = {9},
  journal   = {PLOS ONE},
  number    = {12},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0115715},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-118011},
  pages     = {e115715},
  year      = {2014},
  abstract  = {INTRODUCTION: Recently, we could show that angiotensin II, the reactive peptide of the blood pressure-regulating renin-angiotensin-aldosterone-system, causes the formation of reactive oxygen species and DNA damage in kidneys and hearts of hypertensive mice. To further investigate on the one hand the mechanism of DNA damage caused by angiotensin II, and on the other hand possible intervention strategies against end-organ damage, the effects of substances interfering with the renin-angiotensin-aldosterone-system on angiotensin II-induced genomic damage were studied. METHODS: In C57BL/6-mice, hypertension was induced by infusion of 600 ng/kg • min angiotensin II. The animals were additionally treated with the angiotensin II type 1 receptor blocker candesartan, the mineralocorticoid receptor blocker eplerenone and the antioxidant tempol. DNA damage and the activation of transcription factors were studied by immunohistochemistry and protein expression analysis. RESULTS: Administration of angiotensin II led to a significant increase of blood pressure, decreased only by candesartan. In kidneys and hearts of angiotensin II-treated animals, significant oxidative stress could be detected (1.5-fold over control). The redox-sensitive transcription factors Nrf2 and NF-κB were activated in the kidney by angiotensin II-treatment (4- and 3-fold over control, respectively) and reduced by all interventions. In kidneys and hearts an increase of DNA damage (3- and 2-fold over control, respectively) and of DNA repair (3-fold over control) was found. These effects were ameliorated by all interventions in both organs. Consistently, candesartan and tempol were more effective than eplerenone. CONCLUSION: Angiotensin II-induced DNA damage is caused by angiotensin II type 1 receptor-mediated formation of oxidative stress in vivo. The angiotensin II-mediated physiological increase of aldosterone adds to the DNA-damaging effects. Blocking angiotensin II and mineralocorticoid receptors therefore has beneficial effects on end-organ damage independent of blood pressure normalization.},
  language  = {en}
}
@phdthesis{Classen2021,
  author    = {Claßen, Alexandra},
  title     = {The ERK-cascade in the pathophysiology of cardiac hypertrophy},
  doi       = {10.25972/OPUS-22966},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-229664},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {ERK1/2 are known key players in the pathophysiology of heart failure, but the members of the ERK cascade, in particular Raf1, can also protect the heart from cell death and ischemic injury. An additional autophosphorylation (ERK1 at Thr208, ERK2 at Thr188) empowers ERK1/2 translocation to the nucleus and phosphorylation of nuclear targets which take part in the development of cardiac hypertrophy. Thereby, targeting this additional phosphorylation is a promising pharmacological approach. In this thesis, an in silico model of ERK cascade in the cardiomyocyte is introduced. The model is a semi-quantitive model and its behavior was tested with different softwares (SQUAD and CellNetAnalyzer). Different phosphorylation states of ERK1/2 as well as different stimuli can be reproduced. The different types of stimuli include hypertrophic as well as non-hypertrophic stimuli. With the introduced in-silico model time courses and synergistic as well as antagonistic receptor stimuli combinations can be predicted. The simulated time courses were experimentally validated. SQUAD was mainly used to make predictions about time courses and thresholds, whereas CNA was used to analyze steady states and feedback loops. Furthermore, new targets of ERK1/2 which partially contribute, also in the formation of cardiac hypertrophy, were identified and the most promising of them were illuminated. Important further targets are Caspase 8, GAB2, Mxi-2, SMAD2, FHL2 and SPIN90. Cardiomyocyte gene expression data sets were analyzed to verify involved components and to find further significantly altered genes after induced hypertrophy with TAC (transverse aortic constriction). Changes in the ultrastructure of the cardiomyocyte are the final result of induced hypertrophy.},
  subject      = {Herzhypertrophie},
  language  = {en}
}
@article{FreyGassenmaierHofmannetal.2020,
  author    = {Frey, Anna and Gassenmaier, Tobias and Hofmann, Ulrich and Schmitt, Dominik and Fette, Georg and Marx, Almuth and Heterich, Sabine and Boivin-Jahns, Val{\´e}rie and Ertl, Georg and Bley, Thorsten and Frantz, Stefan and Jahns, Roland and St{\"o}rk, Stefan},
  title     = {Coagulation factor XIII activity predicts left ventricular remodelling after acute myocardial infarction},
  series = {ESC Heart Failure},
  volume    = {7},
  journal   = {ESC Heart Failure},
  number    = {5},
  doi       = {10.1002/ehf2.12774},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236013},
  pages     = {2354-2364},
  year      = {2020},
  abstract  = {Aims Acute myocardial infarction (MI) is the major cause of chronic heart failure. The activity of blood coagulation factor XIII (FXIIIa) plays an important role in rodents as a healing factor after MI, whereas its role in healing and remodelling processes in humans remains unclear. We prospectively evaluated the relevance of FXIIIa after acute MI as a potential early prognostic marker for adequate healing. Methods and results This monocentric prospective cohort study investigated cardiac remodelling in patients with ST-elevation MI and followed them up for 1 year. Serum FXIIIa was serially assessed during the first 9 days after MI and after 2, 6, and 12 months. Cardiac magnetic resonance imaging was performed within 4 days after MI (Scan 1), after 7 to 9 days (Scan 2), and after 12 months (Scan 3). The FXIII valine-to-leucine (V34L) single-nucleotide polymorphism rs5985 was genotyped. One hundred forty-six patients were investigated (mean age 58 ± 11 years, 13\% women). Median FXIIIa was 118 \% (quartiles, 102-132\%) and dropped to a trough on the second day after MI: 109\%(98-109\%; P < 0.001). FXIIIa recovered slowly over time, reaching the baseline level after 2 to 6 months and surpassed baseline levels only after 12 months: 124 \% (110-142\%). The development of FXIIIa after MI was independent of the genotype. FXIIIa on Day 2 was strongly and inversely associated with the relative size of MI in Scan 1 (Spearman's ρ = -0.31; P = 0.01) and Scan 3 (ρ = -0.39; P < 0.01) and positively associated with left ventricular ejection fraction: ρ = 0.32 (P < 0.01) and ρ = 0.24 (P = 0.04), respectively. Conclusions FXIII activity after MI is highly dynamic, exhibiting a significant decline in the early healing period, with reconstitution 6 months later. Depressed FXIIIa early after MI predicted a greater size of MI and lower left ventricular ejection fraction after 1 year. The clinical relevance of these findings awaits to be tested in a randomized trial.},
  language  = {en}
}
@phdthesis{Kramer2021,
  author    = {Kramer, Sofia},
  title     = {Hemmung pathologischer kardialer Hypertrophie {\"u}ber das Dimer-Interface von ERK1/2},
  doi       = {10.25972/OPUS-23373},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233739},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Die extrazellul{\"a}r Signal-regulierten Kinasen 1 und 2 (ERK1/2) spielen eine zentrale Rolle bei der Vermittlung kardialer Hypertrophie und dem Zell{\"u}berleben. Hypertrophe Stimuli aktivieren ERK1/2, triggern deren Dimerisierung und in der Folge die ERK188-Autophosphorylierung. Diese neu entdeckte Autophosphorylierung ist eine Voraussetzung f{\"u}r den nukle{\"a}ren Import von ERK1/2 und f{\"u}hrt zum Entstehen pathologischer kardialer Hypertrophie. Da das Dimer Interface von ERK eine m{\"o}gliche Zielstruktur darstellt, um selektiv die nukle{\"a}ren Signalwege von ERK zu unterbrechen, wurde untersucht, ob man mit Hemmung der ERK-Dimerisierung eine therapeutische M{\"o}glichkeit hat, um pathologische kardiale Hypertrophie zu verhindern. Dazu wurden verschiedene ERK2 Mutanten und Peptide generiert, um die ERK-Dimerisierung zu verhindern. Die Effekte dieser Konstrukte auf die ERK-Dimerisierung und den Kernimport wurden in verschiedenen Zelltypen mittels Fluoreszenzmikroskopie, Co-Immunopr{\"a}zipitationen und Duolink proximity ligation assays getestet. Es konnte gezeigt werden, dass die Peptide effektiv die ERK-ERK Interaktion nach Stimulation mit Phenylephrin und/oder Carbachol verhindern. Zus{\"a}tzlich reduzierten die Peptide ERKT188-Phosphorylierung und in der Folge den ERK-Import in den Nukleus und Kardiomyozytenhypertrophie. Normale ERK-Aktivierung wurde jedoch durch die Peptide nicht verhindert. Insgesamt konnte gezeigt werden, dass das ERK-Dimer Interface eine wertvolle Zielstruktur ist, mit dem man nukle{\"a}re ERK1/2 Signalwege selektiv unterbrechen und damit effektiv Kardiomyozytenwachstum reduzieren kann, ohne gleichzeitig das Zell{\"u}berleben zu gef{\"a}hrden.},
  subject      = {Dimerisierung},
  language  = {de}
}
@phdthesis{Brand2012,
  author    = {Brand, Susanne},
  title     = {Oxidativer Stress und DNA-Sch{\"a}den induziert durch das Peptidhormon Angiotensin II in vivo : Identifizierung des AT1-Rezeptors und reaktiver Sauerstoffspezies als urs{\"a}chliche Faktoren},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-77573},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {Das Renin-Angiotensin-Aldosteron-System (RAAS) reguliert den Blutdruck und den Wasser- und Elektrolythaushalt des K{\"o}rpers. Angiotensin II (Ang II), das aktive Peptid des RAAS, bewirkt eine Vasokonstriktion und in h{\"o}heren Konzentrationen Bluthochdruck. Epidemiologische Studien haben gezeigt, dass eine Verbindung zwischen Hypertonie und dem geh{\"a}uften Auftreten von Krebs besteht. Eine Metaanalyse von 13 Fall-Kontroll-Studien konnte einen Zusammenhang zwischen Hypertonie und einem erh{\"o}hten Risiko, an einem Nierenzellkarzinom zu erkranken nachweisen. In vitro-Studien und Studien an der isolierten Niere konnten bereits genotoxische Effekte des blutdruckregulierenden Hormons Ang II zeigen. Zielsetzung dieser Arbeit war es, zun{\"a}chst in vivo zu pr{\"u}fen, ob steigende Ang II-Konzentrationen einen Einfluss auf die genomische Stabilit{\"a}t von Nieren- und Herzzellen besitzen. Hierzu wurden im Dosisversuch m{\"a}nnliche C57BL/6-M{\"a}use mit osmotischen Minipumpen ausgestattet, die Ang II in vier verschiedenen Konzentrationen zwischen 60 ng/kg min und 1 µg/kg min {\"u}ber einen Zeitraum von 28 Tagen abgeben sollten. W{\"a}hrend des Versuchszeitraums fanden regelm{\"a}ßige, nicht-invasive Blutdruckmessungen an der Maus statt. Die Behandlung mit Ang II f{\"u}hrte zu einem signifikanten Anstieg des Blutdrucks und zu histopathologischen Ver{\"a}nderungen der Glomeruli und des Tubulussystems, was sich in einer verschlechterten Albumin-Ausscheidung wiederspiegelte. Außerdem induzierte die Behandlung mit Ang II die dosisabh{\"a}ngige Bildung von reaktiven Sauerstoffspezies, DNA-Doppelstrangbr{\"u}chen und oxidativer DNA-Sch{\"a}den. Diese Parameter waren bereits in Tieren erh{\"o}ht, die keinen Bluthochdruck entwickelten und stiegen mit der h{\"o}chsten Ang II-Konzentration noch an, obwohl hier im Vergleich zur Vorg{\"a}ngergruppe, die eine geringere Ang II-Konzentration erhielt, kein h{\"o}herer Blutdruck vorlag. Diese Beobachtung deutet auf eine m{\"o}gliche Unabh{\"a}ngigkeit des entstandenen Schadens vom Bluthochdruck hin und lenkt die Aufmerksamkeit auf Ang II als genomsch{\"a}digenden Faktor. Der folgende Interventionsversuch sollte Aufschluss {\"u}ber die m{\"o}gliche blutdruckunabh{\"a}ngige genomsch{\"a}digende Wirkung von Ang II geben. Dazu wurden C57BL/6-M{\"a}use neben der Ang II-Behandlung in einer Konzentration von 600 ng/kg min zus{\"a}tzlich {\"u}ber einen Zeitraum von 28 Tagen mit 5 verschiedenen Substanzen behandelt: Candesartan, Ramipril, Hydralazin, Eplerenon und Tempol. Candesartan ist ein Ang II-Rezeptor-Antagonist, der selektiv den AT1-Rezeptor blockiert. Ramipril wirkt als Hemmer des Angiotensin-Konversions-Enzyms und verhindert die Bildung von endogenem Ang II aus Ang I. Hydralazin, als Vasodilatator, greift nicht in das Renin-Angiotensin-Aldosteron-System ein. Eplerenon blockiert als selektiver Aldosteronantagonist den Mineralkortikoidrezeptor. Tempol wirkt als Antioxidans. Die Behandlung mit Ang II in einer Konzentration von 600 ng/kg min im Interventionsversuch f{\"u}hrte zur Hochregulierung der NADPH-Oxidase 4 und zur Produktion reaktiver Sauerstoffspezies in der Niere und im kardiovaskul{\"a}ren Gewebe. Der entstandene oxidative Stress f{\"u}hrte wiederum zu DNA-Sch{\"a}den und einer Aktivierung der Transkriptionsfaktoren Nrf2 und NF-B. Nrf2-vermittelt wurde die Induktion antioxidativer Gene ausgel{\"o}st, was allerdings nicht ausreichend war, um vor Ang II-induzierten ROS und DNA-Sch{\"a}den zu sch{\"u}tzen. Eine l{\"a}ngerfristige NF-B-Aktivierung durch hohe Ang II-Spiegel kann das {\"U}berleben und die Proliferation von Zellen, die DNA-Sch{\"a}den in Form von Doppelstrangbr{\"u}chen tragen, f{\"o}rdern, was eine Tumor-initiierende Wirkung haben k{\"o}nnte. Die beschriebenen Effekte erh{\"o}hter Ang II-Spiegel konnten durch die Intervention mit dem AT1-Rezeptorblocker Candesartan verhindert werden, was die Beteiligung des Rezeptors nachweist. Eine blutdruckunabh{\"a}ngige, genomsch{\"a}digende Wirkung von Ang II konnte leider durch die Intervention mit Hydralazin nicht verdeutlicht werden, da die erw{\"u}nschte langfristige Blutdrucksenkung ausblieb. Allerdings zeigte die Intervention mit Tempol eine Abnahme an oxidativem Stress und DNA-Sch{\"a}den trotz ausbleibender Blutdrucksenkung. Die Bedeutung von ROS in der Bildung von DNA-Sch{\"a}den und die Unabh{\"a}ngigkeit dieser Sch{\"a}den vom Blutdruck konnten somit hervorgehoben werden. Die Tatsache, dass die Intervention mit Ramipril den Blutdruck nicht senken konnte, der oxidative Stress und die DNA-Sch{\"a}den durch m{\"o}gliche antioxidative Eigenschaften aber vermindert wurden, unterst{\"u}tzt diese Beobachtung. Die Intervention mit Eplerenon f{\"u}hrte zum Teil zu einer Verminderung an ROS und DNA-Sch{\"a}den, brachte diese Parameter aber nicht auf Kontrollniveau zur{\"u}ck. Somit ist eine Beteiligung von Aldosteron nicht auszuschließen.},
  subject      = {Oxidativer Stress},
  language  = {de}
}
@phdthesis{KannenCardoso2013,
  author    = {Kannen Cardoso, Vinicius},
  title     = {The role of Fluoxetine against preneoplastic lesions and tumors in colon tissue},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-77589},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {Introduction: Colon cancer is one of the major human malignancies worldwide, and much effort has been applied to understand the process of colon carcinogenesis, as well as the role of potential treatments and co-therapeutical agents against it. A growing body of evidence suggests that the use of fluoxetine (FLX), an antidepressant belonging to the selective serotonin reuptake inhibitors (SSRIs), may be associated with a reduced colon cancer risk. However, controversial opinions have been published and an identification of the mechanisms of the activity of FLX on colon cells would help in the clarification of this controversy. Objectives: Using several in vitro and in vivo-based methods and analyses, we aimed to verify whether FLX has antioxidant, pro-oxidant or DNA-damaging potential in standard toxicological assays; to check whether and how FLX could prevent and reduce colon preneoplastic lesions; to ascertain whether FLX has any oncostatic potential against colon tumors; and, to investigate whether FLX activity could be comparable with a known and current applied chemotherapeutic agent against colon cancer. Results: FLX did not have any antioxidant potential in our experiments. Although it did not induce reactive oxygen species (ROS) generation or DNA-damage in fibroblast and colon tumor cell lines, FLX reduced dysplasia and proliferation in two different carcinogen models. Further, a significant decrease in colon stromal reactivity and angiogenesis was found in both carcinogen-induced preneoplasia models. In a xenograft model of colon cancer, FLX shrank tumors, reduced tumor proliferation, arrested cancer cells at the G0/G1 cell-cycle phase, and took ROS generation under control. Such effects were detected together with an intracellular acidification and loss of mitochondrial membrane potential in FLX-treated cells. Modulating mitochondrial respiratory chain, HIF-1 expression and Akt/mTOR signaling pathway, FLX was found to reduce colon tumors similar to the widely used chemotherapeutic agent 5-Fluoracil activity. Conclusion: Our collective data suggest that FLX is a remarkable chemopreventive and oncostatic agent against colon preneoplastic lesions and tumors, acting without DNA-damage or ROS generation.},
  subject      = {Fluoxetin},
  language  = {en}
}
@phdthesis{Kaempf2012,
  author    = {K{\"a}mpf, Anne Kristina},
  title     = {Does methylphenidate cause a cytogenetic effect in children with attention deficit hyperactivity disorder?},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-77652},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {MPH wird seit {\"u}ber 50 Jahren zur Therapie des ADHS eingesetzt. Gerade in den letzten Jahren wurde deutlich, dass der Einsatz ohne fundierte Kenntnis {\"u}ber m{\"o}gliche Langzeit-effekte erfolgte, da zum Zeitpunkt der Zulassung aufgrund der begrenzten technischen M{\"o}glichkeiten weniger strenge und weniger umfassende Einschr{\"a}nkungen beachtet wer-den mussten (Walitza, Werner et al. 2007). Da in den letzten Jahren die Anzahl der verschrieben Tagesdosen MPH sprunghaft anstiegen, ist es wichtig, auch die langfristigen Nebenwirkungen von MPH zu untersuchen (Janhsen 2007). Eine Studie von El-Zein et al. von 2005 brachte die Frage auf, ob MPH eventuell Genomsch{\"a}den hervorrufe. Bei 11 von 12 untersuchten Kindern wurde unter der Therapie mit MPH um das 2,4fache erh{\"o}hte Mikrokernfrequenzen gefunden (El-Zein, Abdel-Rahman et al. 2005). Dies beunruhig-te vor allem im Hinblick auf das mit erh{\"o}hten Mikrokernfrequenzen korrelierte erh{\"o}hte Karzinomrisiko. Eine daraufhin von Walitza et al. durchgef{\"u}hrte Studie, die ebenfalls Mikrokernfrequenzen in peripheren Blutzellen untersuchte (Walitza, Werner et al. 2007), konnte keine Hinweise auf eine Genomsch{\"a}digung durch MPH erbringen. Zahlreiche weitere Untersuchungen zur potentiellen Genomsch{\"a}digung durch MPH konnten die Ergebnisse durch in vivo- oder in vitro-Studien nicht best{\"a}tigen und kritisierten die ge-ringe Stichprobengr{\"o}ße sowie mangelnde Transparenz der Arbeit von El-Zein (Preston, Kollins et al. 2005; El-Zein, Hay et al. 2006; Holtmann, Kaina et al. 2006; Suter, Martus et al. 2006). Da jedoch keine weitere Studie sich konkret mit zytogenetischen Effekten in peripheren Blutzellen befasste, soll die vorliegende Arbeit dazu dienen, den Verdacht einer Genomsch{\"a}digung endg{\"u}ltig auszur{\"a}umen (Walitza, Kampf et al. 2009). Dazu wurde eine gr{\"o}ßere Gruppe von Kindern eingeschlossen, sowie Untersuchungen zu verschiedenen Zeitpunkten w{\"a}hrend der MPH-Einnahme, bis hin zu Untersuchungen nach einem Zeitraum von 12 Monaten der MPH- Einnahme, durchgef{\"u}hrt. Mit Hilfe eines Mikrokerntestes wurden in der vorliegenden Studie versucht, DNS-Sch{\"a}den an periphe-ren Lymphozyten zu bestimmen, um daraus auf ein potentiell erh{\"o}htes Krebsrisiko schließen zu k{\"o}nnen. Im Vergleich mit einer gesunden Kontrollgruppe waren die Werte von ADHS-Kindern ohne MPH-Therapie sowie nach 3 und 12 Monaten MPH-Therapie zwar signifikant er-h{\"o}ht, diese gesunde Kontrollgruppe wies jedoch im Vergleich mit internationalen Refe-renzwerten eine extrem niedrige Mikrokernfrequenz auf, so dass davon ausgegangen werden muss, dass diese Vergleiche nur begrenzte Aussagekraft haben. In keiner der verschiedenen mit MPH therapierten Gruppen konnten {\"u}ber die Dauer der Einnahme eine signifikant Erh{\"o}hung der Mikrokernfrequenzen im Vergleich zu den Werten vor Einnahmebeginn nachgewiesen werden, was den Schluss zul{\"a}sst, dass eine Therapie mit Methylphenidat in therapie{\"u}blichen Dosen bei Kindern das Erbgut nicht zu sch{\"a}digen scheint. Dieses Ergebnis best{\"a}tigen inzwischen auch weitere Studien. Der Mikrokerntest erfasst Genomsch{\"a}den, nicht jedoch etwaige tumorpromovierende Eigenschaften des verabreichten Medikaments. Damit ist unklar, ob MPH auf andere Art als {\"u}ber eine Sch{\"a}digung des Genoms das Karzinomrisiko erh{\"o}hen k{\"o}nnte. Erste epidemiologische Studien sehen jedoch keinen Hinweis auf eine wie auch immer entstandene erh{\"o}hte Karzinominzidenz unter der Therapie mit MPH (Selby, Friedman et al. 1989; Oestreicher, Friedman et al. 2007). Hier scheinen jedoch weitere epidemiologische Studien, die m{\"o}g-lichst große Zeitspannen umfassen, n{\"o}tig zu sein},
  subject      = {Methylphenidat},
  language  = {en}
}
@article{HintzscheJastrowKleineOstmannetal.2012,
  author    = {Hintzsche, Henning and Jastrow, Christian and Kleine-Ostmann, Thomas and K{\"a}rst, Uwe and Schrader, Thorsten and Stopper, Helga},
  title     = {Terahertz electromagnetic fields (0.106 THz) do not induce manifest genomic damage in vitro},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-76268},
  year      = {2012},
  abstract  = {Terahertz electromagnetic fields are non-ionizing electromagnetic fields in the frequency range from 0.1 to 10 THz. Potential applications of these electromagnetic fields include the whole body scanners, which currently apply millimeter waves just below the terahertz range, but future scanners will use higher frequencies in the terahertz range. These and other applications will bring along human exposure to these fields. Up to now, only a limited number of investigations on biological effects of terahertz electromagnetic fields have been performed. Therefore, research is strongly needed to enable reliable risk assessment. Cells were exposed for 2 h, 8 h, and 24 h with different power intensities ranging from 0.04 mW/cm2 to 2 mW/cm2, representing levels below, at, and above current safety limits. Genomic damage on the chromosomal level was measured as micronucleus formation. DNA strand breaks and alkali-labile sites were quantified with the comet assay. No DNA strand breaks or alkali-labile sites were observed as a consequence of exposure to terahertz electromagnetic fields in the comet assay. The fields did not cause chromosomal damage in the form of micronucleus induction.},
  subject      = {Toxikologie},
  language  = {en}
}
@inproceedings{LutzSchlatter1978,
  author    = {Lutz, Werner K. and Schlatter, C.},
  title     = {Extrapolation of carcinogenicity data to low doses with a dose-response study of the binding of benzo(a)pyrene to rat liver DNA},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-80157},
  year      = {1978},
  abstract  = {The binding of tritiated benzo(a)pyrene (BP) to liver DNA of 25 adult male rats (SIV 50) has been determined 50 h after a single intraperitoneal injection of doses between 40 ug/kg and 4; mg/kg. The dose-response relations~ ip is linear up to i mg/kg, shows a sigmoid step towards 2 mg/kg and a shallow linear. slope above that value. TlJe 0 bserved bin ding ranges from 1.7 to 180 nmoles BP per mole DNA phosphate. The non-linearity between 1 and 2 mg/kg could be explained 0):1 the basis of an induction of metabolizing enzymes. A pure1y mathematical extrapolation of therumour incidence from a carcinogenic dose (1 x 40mg/kg for a 20\% hepatoma incidence in newborn mice) to human exposure levels (aboilt 0.1 ug/kg per day) would never have followed a step like the on~ found in our experiments. Our dose-effect study therefore shows how carcinogenitity data could be extrapolated in a biologically founded way to low doses.},
  subject      = {Toxikologie},
  language  = {en}
}
@article{WilkenKlotzTawfikSchlieperetal.1990,
  author    = {Wilken, Anke and Klotz, Karl-Norbert and Tawfik-Schlieper, Hoda and Schwabe, Ulrich},
  title     = {Pharmacological characterization of the adenylate cyclase-coupled adenosine receptor in isolated guinea pig atrial myocytes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86061},
  year      = {1990},
  abstract  = {No abstract available.},
  subject      = {Pharmakologie},
  language  = {en}
}
@article{LohseKlotzSchwabe1991,
  author    = {Lohse, Martin J. and Klotz, Karl-Norbert and Schwabe, Ulrich},
  title     = {Mechanism of A2 adenosine receptor activation. I. Blockade of A2 adenosine receptors by photoaffinity labeling},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86073},
  year      = {1991},
  abstract  = {It has previously been shown that covalent incorporation of the photoreactive adenosine derivative (R)-2-azido-N6-p-hydroxyphenytisopropyladenosine [(R)-AHPIA] into the A, adenosine receptor of intact fat cells leads to a persistent activation of this receptor, resulting in a reduction of celular cAMP Ieveis [Mol. Pharmacol. 30:403-409 (1986)]. In contrast, covalent incorporation of (R)-AHPIA into human platelet membranes, which contain only stimulatory A2 adenosine receptors, reduces adenytate cyclase Stimulation via these receptors. This effect of (R)-AHPIA is specific for the A2 receptor and can be prevented by the adenosine receptor antagonist theophylline. Binding studies in-dicate that up to 90\% of A2 receptors can be blocked by photoincorporation of (R)-AHPIA. However, the remaining 10-20\% of A2 receptors are sufficient to mediate an adenylate cyclase Stimulation of up to SOOk of the control value. Similarly, the activation via these 10-20\% of receptors occurs with a halflife that is only 2 times Ionger than that in control membranes. This indicates the presence of a receptor reserve, with respect to both the extent and the rate of adenytate cyclase Stimulation. These observations require a modification of the models of receptor-adenytate cyclase coupling, which is described in the accompanying paper [Mol. Pharmacol. 39:524-530 (1991)].},
  subject      = {Adenosinrezeptor},
  language  = {en}
}
@article{SpielmanKlotzArendetal.1992,
  author    = {Spielman, William S. and Klotz, Karl-Norbert and Arend, Lois J. and Olson, Barbara A. and LeVier, David G. and Schwabe, Ulrich},
  title     = {Characterization of adenosine A1 receptor in a cell line (28A) derived from the rabbit collecting tubule},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86083},
  year      = {1992},
  abstract  = {We have previously reported that in several renal cell types, adenosine receptor agonists inhibit adenylyl cyclase and activate phospholipase C via a pertussis toxin-sensitive G protein. In the present study, in 28A cells, both uf these adenosine receptor-mediated responses were inhibited by 8-cyclopentyl-1,3-dipropylxanthine (DPCPX). a highly selective A1 adenosine receptor antagonist. The binding characteristics of the adenosine A 1 receptor in the 28A renal cell line were studied using the radiolabeled antagonist f:1H]DPCPX to determine whether two separate binding sites could account for these responses. Saturation binding of [: 1H]DPCPX to 28A cell membranes revealed a single class of A1 binding sites with an apparent Kd value of 1.4 nM and maximal binding capacity of 64 fmol/mg protein. Competition experiments with a variety of adenosine agonists gave biphasic displacement curves with a pharmacological profile characteristic of A1 receptors. Comparison of [: 1H]DPCPX competition binding data from 28A cell membranes with rabbit brain membranes, a tissue with well-characterized A1 receptors, reveals that the A 1 receptor population in 28A cells has similar agonist binding affinities to the receptor population in brain but has a considerably lower density. Addition of guanosine ;)' -triphosphate ( 100 ,uM) to 28A cell membranes caused the competition curves to shift from biphasic to monophasic. indicating that the A1 receptors exist in two interconvertible affinity states because of their coupling to G proteins. In the absence of evidence for subpopulations of the A1 receptor, it appears that in 28A cells. A single A1 receptor population. As defined by ligand binding characteristics, couples via one or more pertussis toxin-sensitive guanine nucleotide binding proteins to two different biological signaling mechanisms.},
  language  = {en}
}
@incollection{LohseKlotzSchwabe1985,
  author    = {Lohse, Martin J. and Klotz, Karl-Norbert and Schwabe, Ulrich},
  title     = {Effects of barbiturates on A1 adenosine receptors of rat brain},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-70100},
  publisher      = {Universit{\"a}t W{\"u}rzburg},
  year      = {1985},
  abstract  = {Barbiturates inhibit binding of radioligands to A 1(Ri) adenosine receptors of rat brain membranes. This inhibition is dose-dependent and stereospecific and occurs in the range of pharmacologically active concentrations. The displacement of radiolabelled A1antagonists by barbiturates is not modified by GTP, indicating that barbiturates might act as antagonists at this receptor. This action of barbiturates does not seem to be related to the binding of barbiturates to plasma membranes, as the latter process has different characteristics. Barbiturates also inhibit the binding of radioligands to solubilized A1receptors, and saturation and kinetic experiments suggest that this is due to a competitive antagonism. These results indicate that barbiturates interact with the recognition site of the A1adenosine receptor.},
  subject      = {Barbiturat},
  language  = {en}
}
@incollection{LohseKlotzSchwabe1987,
  author    = {Lohse, Martin J. and Klotz, Karl-Norbert and Schwabe, Ulrich},
  title     = {Functional characterization of A1 adenoosine receptors by photoaffinity labelling},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86097},
  publisher      = {Universit{\"a}t W{\"u}rzburg},
  year      = {1987},
  abstract  = {The ligand-binding subunit ofthe A1 adenosine receptor has been identified in membranes with the photoaffinity Iabel R-2-azido-N6-p-hydroxyphenylisopropyladenosine (R-AHPIA). Covalent labelling ofthe A1 receptor can also be achieved in intact cells. The dissociation of the radioiodinated label (1251-AHPIA) from isolated rat fat cells was incomplete after UV irradiation, leaving about 20°/o of irreversible specific binding. Such covalent labelling of the receptor led to a concentration-dependent reduction of cellular cyclic AMP levels. This persistent effect of covalent labeHing occurred with an IC50 value of 9 nM, as compared to an IC50 value of 0.9 nM for the direct reduction of cyclic AMP Ievels by the ligand. The difference in the IC5o values can be explained by assuming spare receptors. This hypothesis was verified in binding studies using [ 3HJPIA as a radioligand. R-AHPIA inhibited binding of [3H)PIA to intact fat cells with a K1 value of about 20 nM, which is about 20 tim es high er than the corresponding IC50 value of cyclic AMP reduction. These data show that the A1 receptor is activated according to the occupancy theory. The high sensitivity of the activation in intact ceJis is due to a large number of spare receptors.},
  subject      = {Adenosinrezeptor},
  language  = {en}
}
@incollection{LohseKlotzMaureretal.1990,
  author    = {Lohse, Martin J. and Klotz, Karl-Norbert and Maurer, K. and Ott, I. and Schwabe, Ulrich},
  title     = {Effects of adenosine on mast cells},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86101},
  publisher      = {Universit{\"a}t W{\"u}rzburg},
  year      = {1990},
  abstract  = {No abstract available},
  subject      = {Adenosin},
  language  = {en}
}
@incollection{SpielmannArendKlotzetal.1990,
  author    = {Spielmann, W.-S. and Arend, L. J. and Klotz, Karl-Norbert and Schwabe, U.},
  title     = {Adenosine receptors and singnaling in the kidney},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86114},
  publisher      = {Universit{\"a}t W{\"u}rzburg},
  year      = {1990},
  abstract  = {No abstract available.},
  subject      = {Adenosinrezeptor},
  language  = {en}
}
@incollection{SpielmannArendKlotzetal.1991,
  author    = {Spielmann, W. S. and Arend, L. J. and Klotz, Karl-Norbert and Schwabe, U.},
  title     = {Adenosine control of the renal Collecting tubule: receptors and signaling},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86129},
  publisher      = {Universit{\"a}t W{\"u}rzburg},
  year      = {1991},
  abstract  = {No abstract available.},
  subject      = {Adenosin},
  language  = {en}
}
@article{LohseKlotzSchwabe1986,
  author    = {Lohse, Martin J. and Klotz, Karl-Norbert and Schwabe, Ulrich},
  title     = {Effectes of temperature and membrane phase transitions on ligand binding to a2-receptors of human platelets},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86023},
  year      = {1986},
  abstract  = {The binding of agonists and antagonists to a2-adrenergic receptors of human platelets was studied. The receptors showed homogeneaus affinities for antagonists but two affinity states for the agonist (-)-epinephrine, which were modulated by guanine nucleotides. Van't Hoffplots of antagonist binding had a break point at about 18° and considerable diversity between 18° and 0°. Agonist binding to both affinity states showed a similar break point; agonist binding to the high affinity state was characterized by a large entropy component compared to the low affinity state. This entropy component was reduced at higher concentrations of sodium, indicating that it may be due to Iiberation of sodium ions. Measurements of the fluorescence of 1-anilin-8-naphthalenesulfonate showed thermotropic phase transitions of theplatelet membranes at about 17°. The transition temperature was decreased to about 12° by addition of 1 0 mM octanoic acid. Octanoic acidalso shifted the break points of the van't Hoffplot of antagonist and low affinity agonist binding from 18° to 12°. High affinity agonist binding, however, remained unchanged. It is concluded that agonist-specific thennodynamic characteristics of ligand binding to a2-receptors of human platelets can only be investigated by regarding differences between high and low affinity agonist binding. These differences include an entropy increase upon Iigand binding, which is in part due to enhanced liberation of sodium ions, and a loss of sensitivity to fluidity changes in the outer layer of the plasma membrane.},
  subject      = {Molekularpharmakologie},
  language  = {en}
}
@incollection{ShephardSchlatterLutz1987,
  author    = {Shephard, S. E. and Schlatter, C. and Lutz, Werner K.},
  title     = {Model risk analysis of nitrosatable compounds in the diet as precursors of potential endogenous carcinogens},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86188},
  publisher      = {Universit{\"a}t W{\"u}rzburg},
  year      = {1987},
  abstract  = {The potential health risk posed by the endogenous formation of N-nitroso compounds (NOC) from nitrosation of dietary ureas, guanidines, amides, amino acids and amanes (primary, secondary and aromatic) was estimated according to the model: Risk = ( daily intake of precursor] X (gastric concentration of nitrite ]n X [nitrosatability rate constant] X [cilrcinogenicity of derivative]. The daily intakes ofthese compound classes span five orders ofmagnitude (100 g/day amides, top; 1-10 mg/day secondary amines, ureas, bottom); the nitrosation rate constants span seven orders of magnitude (aryl amines, ureas, top; amides, secondary amines, bottom); and the carcinogenicity estimates span a 10 000-fold range from 'very strong' to 'virtually noncarcinogenic'. The resulting risk estimates likewise span an enormous range (nine orders of magnitude ): dietary ureas and aromatic amines combined with high nitrite concentration could pose as great a risk as the intake of preformed N-nitrosodimethylamine in the diet. In contrast, the risk posed by the in-vivo nitrosation of primary and secondary amines is probably negligible. The risk contributed by amides (including protein), guanidines and primary amino acids is intermediate between these two extremes.},
  subject      = {Risikoanalyse},
  language  = {en}
}
@incollection{ShephardHegiLutz1987,
  author    = {Shephard, S. E. and Hegi, M. E. and Lutz, Werner K.},
  title     = {In-vitro assays to detect alkylating and mutagenic activities of dietary components nitrosated in situ},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86194},
  publisher      = {Universit{\"a}t W{\"u}rzburg},
  year      = {1987},
  abstract  = {Nitrosation of dietary components has been combined with the 4-(para-nitrobenzyl)pyridine (NBP) colorimetric test for screening alkylating agents and with the Ames test for the detection of mutagenic activity. This allowed the investigation of short-hved nitrosation products of dietary components which generate electrophilic degradation products requiring no metabolic activation (natural amino acids and some derivatives, ureas, guanidines, primary alkyl and aryl amines). In a first system, precursor, nitrous acid and NBP were present simultaneously. All amino acids tested, except glutamic acid and glutamine, gave positive results. The reactivities spanned more than three orders of magnitude, with the aromatic amino acids and methionine the most active; two primary amines, tryptamine and histamine, were also strongly reactive. All guanidines tested, except the amino acid arginine, gave negative results. A second system consisted of two phases: NBP was added only after destruction of residual nitrite and adjustment of the pH to neutrality. This system was useful for the study of ureas, which are stable in acid but not in neutral media. The range of responses covered more than two orders of magnitude. Most amino acids and primary amines also gave positive results, but could be assessed only after analysing the kinetics of the competing reactions and choosing appropriate reaction times. In a third system, Salmonella typhimurium strain TA1OO replaced NBP. Representatives of the class of amino acids, ureas, the primary amine tryptamine, and aniline became higbly mutagenic upon nitrosation. Methylguanidine was only weakly mutagenic under the present assay conditions. The results indicate that further studies with unstable nitrosation products of dietary components are required to understand more thoroughly the role of endogenous nitrosation in gastric cancer.},
  subject      = {Medizin},
  language  = {en}
}