Human umbilical cord mesenchymal stem cells as treatment of adjuvant rheumatoid arthritis in a rat model

Figure 2 Photomicrograph of rat. A: Negative control group showed intact articular cartilage (C) with normal joint cavity (JC) and synovial tissue (ST) (HE, × 400); B: Photomicrograph of a rat from positive control group showed that hypertrophy and massive mononuclear cell infiltration of the synovial tissue; C: Hypervascularity, congestion, mononuclear cells infiltration (arrows) within vessels (V) wall and rheumatoid nodules (RN); D, E: Inflammatory granulation tissue (arrows) completely obliterated the joint space and; F: Inflammatory granulation tissue (arrows) eroded the articular cartilage (C) and subchondral bone. HE, × 200.