Abstracts Keynote & Plenary

* To whom correspondence should be addressed
Fax: 86-25-83594060 Email: ppshen@nju.edu.cn
Conflict of Interest: The authors declare no conflict of interest.
The tumor suppressor p53 predominantly serves as a sequence
specific transcription factor and
becomes activated upon exposure to diverse stimuli. One potent death inducer PUMA, is
transcriptionally induced by p53. Once released into cytoplasm, it can lead to the activation of Bcl-2
apoptotic network. The cytoplasmic proapoptotic roles of p53 have recently been discovered, which
engage p53 into the chemical interactions with Bcl-2 family members. PUMA can also relieve p53
from the sequestration of antiapoptotic members. Released p53 further enters nucleus and induce
PUMA expression. We proposed that this positive feedback loop can elicit inherent bistability. Further
sensitivity analysis suggested that this system is considerably sensitive to p53 production rate and
downstream effectors are much more affected by sensitive parameters than upstream effectors. Thus,
this newly discovered positive feedback loop might play critical roles in apoptotic network.
Key words: p53, cytoplasm, nuclear, PUMA, bistability, stochastic simulation, local sensitivity, Monte
Carlo
PO-017
The Study of Transesophageal Oxygen Saturation Monitoring
Zhiqiang ZHANG, Bo GAO*, Guojie LIAO, Ling MU, Wei WEI
In this study, transesophageal oxygen saturation (SpO2) monitoring system was established based on
early experiments, to provide a new program of SpO2 acquisition and analysis, and avoid the limitation
of traditional methods. The PPG signal of descending aorta and left ventricular was monitored in the
experiment. The analysis of peak-to-peak value, standard deviation and position of peak in signal
waveform showed that in vivo signal was more stable and sensitive; the physiological information was
reflected in the left ventricular PPG waveform. Therefore, it can be concluded that transesophageal
SpO2 monitoring technology had a better guide in clinical application.
Key words : esophagus, SpO , PPG, left ventricle, descending aorta, standard
deviation, peak-to-peak
2
value
PO-018
Topological
analysis of axon guidance network for Homo sapiens
Chen Xu-ning, Zhu Wei-ping
Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai 200072,
China
Axonal outgrowth is usually guided by a variety of guidance factors, such as netrins, ephrins, slits
and semaphorins, andis one of the critical steps for the proper formation of neural networks. However,
in this stage how the signal molecules function and why some of these play more important roles than
the others in guiding the axonal directional outgrowth has not been answered clearly. In this study, we
try to solve the problem by using the complex network analysis method. The signal molecules and
interacts are treated as the nodes and edges to construct the axon guidance network model for Homo
sapiens. The data of the model are taken from the KEGG database, and an analysis workbench named
Integrative Visual Analysis Tool for Biological Networks and Pathways (VisANT) is employed to
analyze the topological properties, including the degree distribution and the top co-expressed genes of
the axon guidance network. This study has just opened a window onto understanding the mechanism of
the axon guidance.
Key Words: axon guidance,
complex networks, topological properties