Methods The existence of apoptotic cells was determined by DNA gel electrophoresis in 34 cases of astrocytoma.Apoptotic index (AI), mitotic index (MI) and AI/MI ratio were calculated by microscope.

• 方法：利用DNA凝胶电泳确定34例肿瘤细胞群体中细胞凋亡的存在，使用体视学方法计数凋亡指数(AI)、增殖指数(MI)、AI/MI比率。