Figure 4: Heparanase over-expressing transgenic mice exhibit prolonged survival following induction of empyema. Control Balb/C (Con) and heparanase transgenic (Hpa-Tg) mice were inoculated with 2 × 108 CFU of S. pneumonia bacteria and survival of the mice was recorded (A). Lung tissue was collected from surviving mice and postmortem, fixed in formalin and embedded in paraffin. Shown are representative H&E staining of lung specimens (B, middle panels) and pleural space (B, right panels). Specimens were also subjected to immunostaining applying antiheparanase antibody (left panels), depicting over expression of heparanase in lung tissue of Hpa-Tg mice. Note the lack of inflammation in the pleural space and prolonged survival of Hpa- Tg vs. control wild type mice. Original magnification: left panels x40; middle and right panels x10.