@phdthesis{Klein2001,
  author    = {Klein, Andreas},
  title     = {Der altersabh{\"a}ngige Verlust der Geschlechtschromosomen beim Menschen unter Einwirkung von 5-Azadeoxycytidin},
  doi       = {10.25972/OPUS-32771},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-327714},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2001},
  abstract  = {Die vorliegende Arbeit untersucht, ob mit zunehmendem Alter w{\"a}hrend der Mitose h{\"a}ufiger Geschlechtschromsomen verlorengehen. Die Beobachtungen erfolgten an Lymphozytenkulturen gesunder weiblicher und m{\"a}nnlicher Probanden aus drei verschiedenen Altersgruppen. Unter Zugabe von 5-Azadeoxycytidin, einem Nukleosidanalogon, ergab sich in den h{\"o}heren Altersgruppen ein verst{\"a}rktes Auftreten von Mikronuklei. Mikronuklei enthalten Chromosomen oder -bruchst{\"u}cke, die w{\"a}hrend der Mitose nicht in die Tochterzellkerne integriert wurden. Mittels in situ Hybridisierung konnte in den Mikronuklei der Frauen zu 5,5 Prozent ein X-Chromosom, bei den M{\"a}nnern mit 10,7 Prozent {\"u}berzuf{\"a}llig h{\"a}ufig ein Y-Chromosom nachgewiesen werden. Zwischen den einzelnen Altersstufen {\"a}nderte sich dieser Anteil nicht wesentlich. 5-Azadeoxycytidin wird als Nukleosidanalogon w{\"a}hrend der Replikation in die DNA eingebaut und verhindert die Methylierung des Tochterstrangs, da ein Kohlenstoffatom im Pyrimidinrings durch ein Stickstoffatom substituiert ist. Wahrscheinlich resultiert aus der Hyomethylierung eine falsche "Verpackung" des Gonosoms w{\"a}hrend der Mitose, dadurch erfolgt eine fehlerhafte Aufteilung des Chromosoms mit Bildung eines Mikronukleus.},
  language  = {de}
}
@article{WinkelbeinerWandtEbertetal.2020,
  author    = {Winkelbeiner, Nicola and Wandt, Viktoria K. and Ebert, Franziska and Lossow, Kristina and Bankoglu, Ezgi E. and Martin, Maximilian and Mangerich, Aswin and Stopper, Helga and Bornhorst, Julia and Kipp, Anna P. and Schwerdtle, Tanja},
  title     = {A multi-endpoint approach to base excision repair incision activity augmented by PARylation and DNA damage levels in mice: impact of sex and age},
  series = {International Journal of Molecular Sciences},
  volume    = {21},
  journal   = {International Journal of Molecular Sciences},
  number    = {18},
  issn      = {1422-0067},
  doi       = {10.3390/ijms21186600},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-285706},
  year      = {2020},
  abstract  = {Investigation of processes that contribute to the maintenance of genomic stability is one crucial factor in the attempt to understand mechanisms that facilitate ageing. The DNA damage response (DDR) and DNA repair mechanisms are crucial to safeguard the integrity of DNA and to prevent accumulation of persistent DNA damage. Among them, base excision repair (BER) plays a decisive role. BER is the major repair pathway for small oxidative base modifications and apurinic/apyrimidinic (AP) sites. We established a highly sensitive non-radioactive assay to measure BER incision activity in murine liver samples. Incision activity can be assessed towards the three DNA lesions 8-oxo-2'-deoxyguanosine (8-oxodG), 5-hydroxy-2'-deoxyuracil (5-OHdU), and an AP site analogue. We applied the established assay to murine livers of adult and old mice of both sexes. Furthermore, poly(ADP-ribosyl)ation (PARylation) was assessed, which is an important determinant in DDR and BER. Additionally, DNA damage levels were measured to examine the overall damage levels. No impact of ageing on the investigated endpoints in liver tissue were found. However, animal sex seems to be a significant impact factor, as evident by sex-dependent alterations in all endpoints investigated. Moreover, our results revealed interrelationships between the investigated endpoints indicative for the synergetic mode of action of the cellular DNA integrity maintaining machinery.},
  language  = {en}
}
@article{WernerChenMayaetal.2018,
  author    = {Werner, Rudolf A. and Chen, Xinyu and Maya, Yoshifumi and Eissler, Christoph and Hirano, Mitsuru and Nose, Naoko and Wakabayashi, Hiroshi and Lapa, Constantin and Javadi, Mehrbod S. and Higuchi, Takahiro},
  title     = {The Impact of Ageing on 11C-Hydroxyephedrine Uptake in the Rat Heart},
  series = {Scientific Reports},
  volume    = {8},
  journal   = {Scientific Reports},
  number    = {11120},
  issn      = {2281-5872},
  doi       = {10.1038/s41598-018-29509-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164826},
  year      = {2018},
  abstract  = {We aimed to explore the impact of ageing on 11C-Hydroxyephedrine (11C-HED) uptake in the healthy rat heart in a longitudinal setting. To investigate a potential cold mass effect, the influence of specific activity on cardiac 11C-HED uptake was evaluated: 11C-HED was synthesized by N-methylation of (-)-metaraminol as the free base (radiochemical purity >95\%) and a wide range of specific activities (0.2-141.9 GBq/μmol) were prepared. \(^{11}\)C-HED (48.7±9.7MBq, ranged 0.2-60.4μg/kg cold mass) was injected in healthy Wistar Rats. Dynamic 23-frame PET images were obtained over 30 min. Time activity curves were generated for the blood input function and myocardial tissue. Cardiac 11C-HED retention index (\%/min) was calculated as myocardial tissue activity at 20-30 min divided by the integral of the blood activity curves. Additionally, the impact of ageing on myocardial 11CHED uptake was investigated longitudinally by PET studies at different ages of healthy Wistar Rats. A dose-dependent reduction of cardiac 11C-HED uptake was observed: The estimated retention index as a marker of norepinephrine function decreased at a lower specific activity (higher amount of cold mass). This observed high affinity of 11C-HED to the neural norepinephrine transporter triggered a subsequent study: In a longitudinal setting, the 11C-HED retention index decreased with increasing age. An age-related decline of cardiac sympathetic innervation could be demonstrated. The herein observed cold mass effect might increase in succeeding scans and therefore, 11C-HED microPET studies should be planned with extreme caution if one single radiosynthesis is scheduled for multiple animals.},
  subject      = {Positronen-Emissions-Tomografie},
  language  = {en}
}
@inproceedings{WernerChenHiranoetal.2018,
  author    = {Werner, Rudolf A. and Chen, Xinyu and Hirano, Mitsuru and Nose, Naoko and Lapa, Constantin and Javadi, Mehrbod S. and Higuchi, Takahiro},
  title     = {The Impact of Ageing on [\(^{11}\)C]meta-Hydroxyephedrine Uptake in the Rat Heart},
  series = {Journal of Nuclear Medicine},
  volume    = {59},
  booktitle = {Journal of Nuclear Medicine},
  number    = {Supplement No 1},
  issn      = {0161-5505},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-162228},
  pages     = {100},
  year      = {2018},
  abstract  = {No abstract available.},
  subject      = {Positronen-Emissions-Tomografie},
  language  = {en}
}
@inproceedings{WernerMarcusSheikhbahaeietal.2018,
  author    = {Werner, Rudolf A. and Marcus, Charles and Sheikhbahaei, Sara and Higuchi, Takahiro and Solnes, Lilja B. and Rowe, Steven P. and Buck, Andreas K. and Lapa, Constantin and Javadi, Mehrbod S.},
  title     = {The Impact of Ageing on Dopamine Transporter Imaging},
  series = {Journal of Nuclear Medicine},
  volume    = {59},
  booktitle = {Journal of Nuclear Medicine},
  number    = {Supplement No 1},
  issn      = {0161-5505},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-162213},
  pages     = {1646},
  year      = {2018},
  abstract  = {No abstract available.},
  subject      = {Parkinson-Krankheit},
  language  = {en}
}
@phdthesis{Klein2001,
  author    = {Klein, Andreas},
  title     = {Der altersabh{\"a}ngige Verlust der Geschlechtschromosomen beim Menschen unter Einwirkung von 5-Azadeoxycytidin},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-1181416},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2001},
  abstract  = {Die vorliegende Arbeit untersucht, ob mit zunehmendem Alter w{\"a}hrend der Mitose h{\"a}ufiger Geschlechtschromsomen verlorengehen. Die Beobachtungen erfolgten an Lymphozytenkulturen gesunder weiblicher und m{\"a}nnlicher Probanden aus drei verschiedenen Altersgruppen. Unter Zugabe von 5-Azadeoxycytidin, einem Nukleosidanalogon, ergab sich in den h{\"o}heren Altersgruppen ein verst{\"a}rktes Auftreten von Mikronuklei. Mikronuklei enthalten Chromosomen oder -bruchst{\"u}cke, die w{\"a}hrend der Mitose nicht in die Tochterzellkerne integriert wurden. Mittels in situ Hybridisierung konnte in den Mikronuklei der Frauen zu 5,5 Prozent ein X-Chromosom, bei den M{\"a}nnern mit 10,7 Prozent {\"u}berzuf{\"a}llig h{\"a}ufig ein Y-Chromosom nachgewiesen werden. Zwischen den einzelnen Altersstufen {\"a}nderte sich dieser Anteil nicht wesentlich. 5-Azadeoxycytidin wird als Nukleosidanalogon w{\"a}hrend der Replikation in die DNA eingebaut und verhindert die Methylierung des Tochterstrangs, da ein Kohlenstoffatom im Pyrimidinrings durch ein Stickstoffatom substituiert ist. Wahrscheinlich resultiert aus der Hyomethylierung eine falsche "Verpackung" des Gonosoms w{\"a}hrend der Mitose, dadurch erfolgt eine fehlerhafte Aufteilung des Chromosoms mit Bildung eines Mikronukleus.},
  language  = {de}
}