Fig. 1.
After the terminal deoxynucleotydyl transferase mediated dUTP nick-end labeling (TUNEL) reaction, (A) condensed apoptotic osteocytes in cancellous bone from a femoral head removed from a patient with steroid-induced osteonecrosis show intense green fluorescence (× 400). (B) In a patient with alcohol-induced osteonecrosis, intermediate fluorescence is shown (× 100). Non-apoptotic cells are not visible using immunofluorescence microscopy. (C) In a patient with idiopathic osteonecrosis, no fluorescence is shown (× 100).