1.Study of microsatellite instability in epithelial ovarian tumors
Yuan LU ; Xishi LIU ; Yuexiang WANG ; Houyan SONG ; Nanbert ZHONG
Journal of Peking University(Health Sciences) 2006;38(1):62-65
Objective: To evaluate the frequency of MSI in epithelial ovarian tumors and its relationship with clinicopathologic features. Methods: Ninety fresh specimens of epithelial ovarian tumors, including 74 primary and 16 secondary tumors, were collected. Microsatellite analysis was carried out using 5 mono- and dinucleotide markers from the National Cancer Institute Consensus Panel by fluorescence-labeled polymerase chain reaction. Results: Of 90 epithelial ovarian tumors analyzed, 18 demonstrated a high level of microsatellite instability (MSI-H), 30 demonstrated a low level of microsatellite instability (MSI-L), and the remaining 42 exhibited microsatellite stability (MSS). Frequency of microsatellite instability (MSI) at loci BAT-25 was higher than that at any other loci. No correlation was found between MSI level and patient age, tumor type, tumor differentiation (P>0.05). But the microsatellite instability-high phenotype correlates with clinical stage.It tended to occur more frequently in early-stage tumors (P=0.03). Conclusion: The frequent MSI in epithelial ovarian tumors suggests that it is an early event to involve in the development of epithelial ovarian tumors.
2.Biodynamic responses of the seated posture of human upper-body under horizontal and vertical stimuli.
Xishi WANG ; Fuchuan JIANG ; Jian MA ; Xinping HOU
Journal of Biomedical Engineering 2008;25(1):101-104
In this paper, a biodynamic model of human upper-body in the seated posture is developed. Based on d'Alembert's principle, the non-linear biodynamic equation of the modelling is derivated. Furthermore, the function of frequency and amplitude of modelling is obtained by employing the KB method in the non-linear theory. The response of realistic human parameters and the external stimulus on the modelling is simulated by MATLAB. The results show that the modelling presents a plenty of non-linear characteristics. The parameters identified and the stable areas to keep the stabilization of upper-body in the seated posture are discussed. These data can be used to explain and estimate the mechanism for the maintenance of stable trunk posture due to the mechanical shocks transmitted through the vehicle seat.
Automobile Driving
;
Biomechanical Phenomena
;
Humans
;
Low Back Pain
;
etiology
;
Models, Biological
;
Nonlinear Dynamics
;
Posture
;
physiology
;
Spine
;
physiology
;
Vibration