OBJECTIVE:To prepare nifedipine (NF) hollow controlled-release microspheres and evaluate the quality. METH-ODS:Solvent diffusion volatilization method was used to prepare microspheres,using comprehensive scores of cumulative release in 2,12,24 h(Q2 h,Q12 h,Q24 h)as indexes,orthogonal test was designed to screen the carrier material ethyl cellulose(EC),poly-vinyl pyrrolidone(PVP)and main drug NF amounts;appearance,particle size distribution,drug loading,floating and cumulative release of the microspheres prepared by optimal formulation were evaluated and compared of in vitro release behavior with imported preparation of Nifedipine controlled-release tablets (Adalat?). RESULTS:The optimal formulation was as follow as NF 3.00 g, PVP 1.60 g,EC 15.65 g. Prepared NF hollow controlled-release microspheres were spherical in shape with particle size distribution of 24-40 mesh and drug loading of 8.66%;24 h floating rate in release medium was 97.93%,Q2 h,Q12 h,Q24 h were 20.49%, 52.90%,91.00%(RSD<10%,n=3). Compared with the imported preparation,similarity factor f2 values of cumulative release were higher than 50,showing in vitro drug-release was consistent with the zero-order kinetic equation (r=0.9993);n of Rit-ger-Peppas equation (r=0.9807) was 0.478. CONCLUSIONS:Prepare NF hollow controlled-release microspheres show similar drug-release behavior with the imported preparation,the drug is released by the combination of diffusion and erosion.

Aim To investigate the expression and im-plication of HIF-1α, ROCK-2 , FoxM1 in PC12 cell in-jury induced by lead acetate. Methods PC12 cells were treated with lead acetate at the doses of 100 , 200 and 400 μmol·L-1 . The cell viability was determined by MTT reduction assay and LDH assay, the intracellu-lar production of oxygen species was measured by as-sessing SOD and MDA levels, cell apoptosis was deter-mined by Hoechst 33342 staining, the expressions of HIF-1α, ROCK-2 , FoxM1 , Bcl-2 and Bax were deter-mined by immunoblotting analysis. Results Lead ac-etate induced cell injury in PC12 cells in a dose-de-pendent manner, and it potentiated oxygen radical pro-duction and cell apoptosis. In addition, lead acetate enhanced HIF-1α and ROCK-2 expressions, increased Bax/Bcl-2 ratio and decreased FoxM1 expression. Conclusion Lead acetate can induce PC12 cell apop-tosis, which may be related with the expressions of HIF-1α, ROCK-2 and FoxM1 . Cellular oxidative stress may contribute to the injury as well.

Objective To study the expressions of P53,vascular endothelial growth factor (VEGF) and proliferating cell nuclear antigen (PCNA) in astrocytomas and their relationships with prognosis of these patients.Methods Immunohistochemical SP method was employed to detect the P53,VEGF and PCNA expression in 126 cases of human brain astrocytomas of different grades,collected in our hospital from May 2002 to May 2010; their correlations and their significance in the prognosis in these patients were analyzed.Results P53,VEGF,and PCNA expressed differently in astrocytomas of different grades,enjoying a positive relation with grades (P＜0.05); positive correlations of between P53 expression and both VEGF and PCNA expressions (r=0.608,P=0.000; r=0.432,P=0.001).In patients with the same grade of astrocytoma,those having positive P53 expression enjoyed poorer prognosis and lower survival rate with significant difference (P＜0.05); while VEGF and PCNA expressions had no correlation with the progonosis.Conclusion The expressions of PCNA,VEGF and P53 are closely associated with grade of the astrocytomas,and only P53 expression is an indicator of poor prognosis.