FIGURE 1

Adenovirus (Ad) delivered intracolorectally (ICR) transfers gene to the colorectal mucosa. (a) Paraffin-embedded sections of the colorectum were stained with 5-bromo-4-chloro-3-indolyl -D-galactoside (X-gal) 2 days after ICR administration of 2 10⁹ PFU Ad-gal. Cell-associated positively stained blue clusters along the epithelium are indicated with arrows. Microscopy images with 200 magnification were connected end-to-end using Adobe Photoshop to reveal 2-cm-long distal-half colorectums (photo reduced). (b) Paraffin-embedded sections with -gal staining in LP (left panel) or lymphoid follicles (right panel) at day 2. Original magnification 400 and 800, respectively. (c) -Gal-expressing cells were enumerated at day 2. The number is averaged from longitudinal tissue sections of three different whole colorectum. (d, e) Luciferase (Luc) enzymatic activity was measured at 2 days or as indicated after ICR administration of AdLuc. Luc activity determined by an increase in relative light unit (RLU) compared to background is expressed as means.e.m. from three mice in each group. *P<0.05, **P<0.01, ***P<0.001. Results are representative of at least two independent experiments. -gal, -galactosidase; PFU, plaque-forming unit.