Peptidoglycan–polysaccharide (PG-PS)-induced polyarthritis is attenuated in CD14 knockout animals: gross observation score. Acute PG-PS polyarthritis was induced by intravenous injection of PG-PS (3 mg/kg). The arthritis index was scored as described in the Materials and methods section. Each point represents a mean ± standard error of the mean in 16–19 animals. The significance of the difference between the groups was evaluated by Mann–Whitney rank sum test. *P < 0.05.