FIG. 1.

Effects of local injections of F. nucleatum on murine calvarial bone and soft tissue. Live F. nucleatum bacteria (2 × 10⁷) were injected once daily for 6 days into the s.c. tissues overlying the calvaria of mice, and the animals were sacrificed 24 h later. Edema and abscesses (A) developed in the soft tissue overlying the calvarium of this mouse injected with F. nucleatum. In addition, increased numbers of osteoclasts (arrows) were seen inside the calvarium, and these caused an increase in the size of the bone marrow spaces (see Fig. 2C for comparison) due to increased endosteal bone resorption. Hematoxylin-eosin stain was used.