Objective To study radiation protection of low dose CT scanning in orbit. Methods 126 cases of orbital disease were scanned by original standard parameter (130 kV,100 mA) and two different low dose parameters (130 kV,50 mA and 30 mA) respectively. All the images were reconstructed by different Kernels. The image quality and difference of the CTDIw (weighted CT dose index) of each group were compared. Results CTDIw was 30% of that of the conventional scanning and least when 130 kV 30 mA,but the difference of the image quality compared with that by conventional scanning was highly statistical significance (P0.05). Conclusion Low dose CT scanning (50mA) in orbit not only can assure the image quality but also can decrease the radiation dose.

Objective To study a gastric carcinoma subcell line with higher invasive potential and its biologic characteristics screened by a transwell chamber. Methods Transwell chamber was used for the selection of tumor subline. The biological characteristics of the cell lines were studied with optics microscope, Westem blotting, Transwell, immunohistochemical staining and growth curve. Results A gastric carcinoma cell subcell line (named MKN-28S10) was established from its parent cell line MKN-28 with higher invasive potential. MKN-28S10 showed essentially the same morphous as MKN-28. The expression of E-cadherin and TIMP-1 decreased significantly in the screened subcell line(P<0.05). The expression of NM23-H1 in MKN-28S10 was significantly lower than that in MKN-28 (P<0.05). Compared with MKN-28 (61.75±2.06 per vision), the migrative ability of passing through the membrane Millipore(100.25±0.50 per vision) was obviously increased in MKN-28S10(P<0.05). Compared with MKN-28, the growth rate of MKN-28S10 was increased obviously. Conclusion MKN-28S10 cell has stronger invasive ability and more powerful proliferation than that of its mother line MKN-28.