Beziehungen zwischen der Chromatinstruktur und Apoptose-bedingter DNA-Fragmentierung

Während des programmierten Zelltods (=Apoptose) kommt es zur Bildung von DNA-Fragmenten unterschiedlicher Größe. Ziel der vorliegenden Arbeit war es, die Fragmentierung des Chromatins während der Apoptose zu untersuchen, um Erkenntnisse über den zeitlichen und räumlichen Ablauf und die Zusammenhänge zwischen der Apoptose-bedingten Chromatinfragmentierung und der Chromatinstruktur zu gewinnen. Zur Untersuchung der Apoptose-bedingten Fragmentierung des Chromatins wurden verschiedene Zellinien, Induktoren mit Wirkung auf die verschiedenen Apoptose-Signalwege, die Anreicherung von apoptotischen Zellen durch magnetische Separation, die Induktion der Apoptose auf verschiedenen Stufen des Signalwegs, "in vitro"-Assays mit isolierten Kernen sowie die vorherige Synchronisierung der Zellen in Kombination mit einem Zellzyklus-Phasen-spezifischen Apoptose-Induktor getestet, etabliert und optimiert. Die Fragmentierung der DNA wurde sowohl im Vergleich funktionell verschiedener Chromatinregionen (Zentromer/Telomer/LINE/SINE-Elemente), als auch im Detail in einer Modellregion, dem Histongencluster auf Chromosom 6 untersucht

Positive Behavior Support Systems in a Rural West Texas Middle School

Positive Behavior Support (PBS) programs are being implemented in schools in the United States to support faculty, staff, and students. The purpose of this study was to evaluate a PBS system at a rural west Texas middle school to discover what improvements are necessary for district-wide implementation and sustainability. The study drew on Bandura\u27s social learning theory, which posits that people learn from each other through observation, imitation, and modeling. PBS systems provide the framework for exhibiting specific behavior expectations so students and teachers can get the most from their educational experiences. A program evaluation was completed using discipline data from 2008-2012 from the middle school, observations at the middle school, and archival campus improvement plan results from the campus needs assessment from 2012. The research instrument used to assess the information was a pre-established PBS evaluation system called the School-Wide Evaluation Tool (SET) designed for programmatic assessment. The SET assessment tool guided the evaluation of information gathered from 100 students, 15 teachers, and an administrative team survey to highlight the strengths and weaknesses of the PBS program in the school and district, identify necessary changes to improve its effectiveness, and determine how to best implement the system district-wide. These findings were used to inform a white paper outlining how to implement a successful program and how to maintain the program over time. This evaluation provided specific steps to strengthen each component of a PBS program to ensure school-wide application and sustainability. A positive social change is experienced by students, teachers, and parents by the enhancement of a PBS system that improves student behavior in the school and district

Overexpression of Eag1 potassium channels in clinical tumours

BACKGROUND: Certain types of potassium channels (known as Eag1, KCNH1, Kv10.1) are associated with the production of tumours in patients and in animals. We have now studied the expression pattern of the Eag1 channel in a large range of normal and tumour tissues from different collections utilising molecular biological and immunohistochemical techniques. RESULTS: The use of reverse transcription real-time PCR and specifically generated monoclonal anti-Eag1 antibodies showed that expression of the channel is normally limited to specific areas of the brain and to restricted cell populations throughout the body. Tumour samples, however, showed a significant overexpression of the channel with high frequency (up to 80% depending on the tissue source) regardless of the detection method (staining with either one of the antibodies, or detection of Eag1 RNA). CONCLUSION: Inhibition of Eag1 expression in tumour cell lines reduced cell proliferation. Eag1 may therefore represent a promising target for the tailored treatment of human tumours. Furthermore, as normal cells expressing Eag1 are either protected by the blood-brain barrier or represent the terminal stage of normal differentiation, Eag1 based therapies could produce only minor side effects