Tetrandrine Exerts a Radiosensitization Effect on Human Glioma through Inhibiting Proliferation by Attenuating ERK Phosphorylation.

Tetrandrine (Tet), a bisbenzylisoquinoline alkaloid, has been reported to have a radiosensitization effect on tumors. However, its effects on human glioma and the specific molecular mechanisms of these effects remain unknown. In this study, we demonstrated that Tet has a radiosensitization effect on human glioma cells. It has been hypothesized that Tet has a radiosensitization effect on glioma cells by affecting the glioma cell cycle and DNA repair mechanism and that ERK mediates these activities. Therefore, we conducted detailed analyses of the effects of Tet on the cell cycle by performing flow cytometric analysis and on DNA repair by detecting the expression of phosphorylated H2AX by immunofluorescence. We used western blot analysis to investigate the role of ERK in the effect of Tet on the cell cycle and DNA repair. The results revealed that Tet exerts its radiosensitization effect on glioma cells by inhibiting proliferation and decreasing the expression of phosphorylated ERK and its downstream proteins. In summary, our data indicate that ERK is involved in Tet-induced radiosensitization of glioma cells via inhibition of glioma cell proliferation or of the cell cycle at G0/G1 phase.

Maximal aerobic power in children and adolescents of Beijing, China.

The maximal aerobic power of 463 Chinese children and adolescents, 10-19 years, is described. The absolute values of maximal oxygen intake (V̇O2 max) in boys and girls were 1.75-3.26 and 1.44-2.10 L/min, respectively. Relative values of V̇O2 max per unit stature (V̇O2 max/stature) were 12.35-19.42 ml/cm.min for boys and 10.18-13.42 ml/cm.min for girls, values per unit weight (V̇O2 max/weight) were 48.60-56.59 ml/kg.min for boys and 39.34-45.56 ml/kg.min for girls, and values per estimated unit lean body mass (V̇O2 max/lean-body-mass) were 58.98-65.28 ml/kg.min for boys and 54.90-59.04 ml/kg.min for girls. Maximal values of oxygen pulse (V̇O2 max/HRmax) were 8.58-16.67 ml/beat for boys and 6.88-10.35 ml/beat for girls. In early adolescence, V̇O2 max, V̇O2 max/stature, and V̇O2 max/HRmax increased with chronological age, but the increment was less in girls. In contrast, V̇O2 max/weight and V̇O2 max/LBM did not increase with age in boys and girls. All indicators of V̇O2 max were lager in boys than in girls. © 1996 Wiley-Liss, Inc.