Quantitative analysis of bone damage. Mice (n = 4 for each treatment group) were injected with the adenoviral vectors expressing oncostatin M (OSM), IL-1 or tumour necrosis factor alpha (TNF-α) as described in Fig. 1. Sections (5 μm) were stained with H&E and were scored for bone damage as described in Materials and methods. The values represent the mean ± standard error of the mean for each treatment group (the control scored 0). The total scores are the combined scores of the four mice in each treatment group. Statistical differences between each treatment within experiments were determined using Student's t test: * P ≤ 0.05.