Under square loss, this paper constructs the empirical Bayes（EB） estimation for the parameter of normal distribution which has both asymptotic optimality and admissibility. Moreover, the convergence rate of the EB e...Under square loss, this paper constructs the empirical Bayes（EB） estimation for the parameter of normal distribution which has both asymptotic optimality and admissibility. Moreover, the convergence rate of the EB estimation obtained is proved to be O（n^-1）.展开更多
Objective:To investigate the effect and mechanism of nordihydroguaiaretic acid (NDGA) on apoptosis in human malignant glioma cell line SHG-44. Methods: Cell growth inhibition was measured with MTT assay. Cell apoptosi...Objective:To investigate the effect and mechanism of nordihydroguaiaretic acid (NDGA) on apoptosis in human malignant glioma cell line SHG-44. Methods: Cell growth inhibition was measured with MTT assay. Cell apoptosis was observed with light and electron microscopy and TUNEL. Expression of bcl-2 gene was measured with immunohistochemistry, in situ hybridization and image analyses. Results: NDGA at the concentration of 100 μmol/L inhibited the proliferation of SHG-44 cells and induced apoptosis in a time-dependent manner. The expression of Bcl-2 protein in SHG-44 cells was decreased in the present of 100 μmol/L NDGA along with the duration of treatment in a negative correlation with the degree of cell apoptosis. The bcl-2 mRNA expressed in SHG-44 cells was reduced after treatment with 100 μmol/L NDGA, apparently consistent with the immunohistochemical results. Conclusion: NDGA can induce apoptosis of human malignant glioma cells probably by down-regulating expression of bcl-2 gene, though the exact mechanism needs further study.展开更多
基金Supported by the Natural Science Foundation of China(70471057)Supported by the Natural Science Foundation of Education Department of Shaanxi Province(03JK065)
文摘Under square loss, this paper constructs the empirical Bayes（EB） estimation for the parameter of normal distribution which has both asymptotic optimality and admissibility. Moreover, the convergence rate of the EB estimation obtained is proved to be O（n^-1）.
基金National Natural Science Foundation of China (No. 39670296)
文摘Objective:To investigate the effect and mechanism of nordihydroguaiaretic acid (NDGA) on apoptosis in human malignant glioma cell line SHG-44. Methods: Cell growth inhibition was measured with MTT assay. Cell apoptosis was observed with light and electron microscopy and TUNEL. Expression of bcl-2 gene was measured with immunohistochemistry, in situ hybridization and image analyses. Results: NDGA at the concentration of 100 μmol/L inhibited the proliferation of SHG-44 cells and induced apoptosis in a time-dependent manner. The expression of Bcl-2 protein in SHG-44 cells was decreased in the present of 100 μmol/L NDGA along with the duration of treatment in a negative correlation with the degree of cell apoptosis. The bcl-2 mRNA expressed in SHG-44 cells was reduced after treatment with 100 μmol/L NDGA, apparently consistent with the immunohistochemical results. Conclusion: NDGA can induce apoptosis of human malignant glioma cells probably by down-regulating expression of bcl-2 gene, though the exact mechanism needs further study.
