Cross sections of menisci exhibiting synthesis of proinflammatory and anti-inflammatory molecules as a result of CPM and IM treatment of AIA knees. Sections from rabbit knees subjected to CPM or IM were immunostained to examine COX-2 (Column I), MMP-1 (Column II), IL-1 (Column III), or IL-10 (Column IV). In all columns sections from untreated control knees are A, sections from AIA knees subjected to various treatments are: (B) IM for 24 h, (C) CPM for 24 h, (D) IM for 48 h, and (E) CPM for 48 h. Each photograph represents one out of five sections obtained from different animals receiving identical treatments. Arrows point to cells positive for each mediator.