ABSTRACT
Aim To investigate the effects of polysac-charides from Ginkgo biloba on the proliferation, apop-tosis of mouse 4T1 breast cancer cells and the possible mechanism. Methods 4T1 cells in logarithmic growth phase were treated with polysaccharides from Ginkgo biloba of different concentrations. The effect of poly-saccharides from Ginkgo biloba on inhibition of prolif-eration and cytotoxicity of 4T1 cells was determined by MTT assay and trypan blue exclusion assay respective-ly. The apoptotic effect of polysaccharides from Ginkgo biloba on 4T1 cells was detected by DAPI staining. qRT-PCR experiments were carried out for the detec-tion of gene expressions of the glucose transporter fami-ly upon the treatment with the polysaccharides from Ginkgo biloba. Results Polysaccharides from either Ginkgo biloba leaf or Ginkgo biloba exocarp significant-ly inhibited the proliferation of 4T1 cells in a dose-and time-dependent manner. Moreover, with the increasing doses of polysaccharides, cell viability decreased, ac-companied by the increased cell cytotoxicity and apop-tosis. qRT-PCR results showed that polysaccharides from Ginkgo biloba significantly reduced glucose trans-porter 1 gene expression. Conclusions Polysaccha-rides from Ginkgo biloba can both inhibit 4T1 cell pro-liferation and induce cell apoptosis, and by regulating glucose transporter family gene expression, it interfered with cell energy metabolism, which infers that the effects of cell proliferation inhibition as well the apopto-sis induction might be due to the regulation of glucose transporter family gene expression.
ABSTRACT
<p><b>OBJECTIVE</b>To analyze stress around the impacted tooth by constituting a 3-dimensional finite element model of impacted tooth, consequently offer reference basis for clinic traction treatment.</p><p><b>METHODS</b>The 3-dimensional finite element model of the impacted tooth was constituted by CT scan, append pericementum and alveolar bone model was used to constitute impacted model. 3 forces were loaded to 3-dimensional finite element model and the periodontal stress of impacted tooth was calculated.</p><p><b>RESULTS</b>When force 1 was loaded to the model, the maximum stress was smaller, but the stress distribution was more average. When force 3 was loaded to the model, the maximum stress was larger, but the stress concentrated at the side of the force. When force 2 was loaded to the model, the stress distribution was medium.</p><p><b>CONCLUSION</b>When the direction of the force is in line with the central axis, the maximum stress is smaller, and the stress distribution is more average, while this has advantage to the eruption of the impacted tooth. When the direction of the force has angle with the central axis of the impacted tooth, the angle is larger, the maximum stress is larger and the stress distribution is more concentrate, and this goes against the eruption of the impacted tooth. The angle between the orientation of the traction and central axis of the impacted tooth is smaller, there are more advantages to the eruption of the impacted tooth. So the angle should be properly selected in order to make sure of the eruption of the impacted tooth. When the angle is quite large, more anchorage is needed to resist to the large force.</p>