The long (a) and short (b) diameters were measured from the ultrasonic images. The volume of tumor was calculated according to the following formula: a × b2/2. TUNEL staining TUNEL staining was described previously [19]. Formalin-fixed tissues were dehydrated, embedded in paraffin, and sectioned. Tissue sections were deparaffinized with xylene

and rehydrated with graded dilution of ethanol and fixed by 4% paraformaldehyde. The tissue sections were incubated in 0.1% Triton X-100 in 0.1% sodium citrate (SSC) for 15 min and 0.3% H2O2 for 3 – 5 min. The slides were washed three times in phosphate-buffered saline (PBS) and incubated with 50 μl of TUNEL reaction mixture (TdT and fluorescein-labeled dUTP) in a humid atmosphere for 60 min at 37°C. After three washes in PBS, the sections were incubated for 30 min with an antibody MK 8931 specific for fluorescein-conjugated horseradish peroxidase. The TUNEL stain was visualized with a DAB substrate system in selleck which nuclei with DNA fragmentation stained brown. Slides were mounted in neutral gum medium and were observed with an IX71 light microscope (Olympus, Tokyo, Japan). A commercial fluorometric TUNEL system (DeadEnd; Promega, Madison, WI) was used for analysis of TPCA-1 in vivo apoptosis. Tissue sections were examined microscopically using a 40× objective; apoptotic cells were counted in 200 fields. Alternatively, lenses were dissected from Formalin-fixed

eyeballs and pictures were taken with an MZ FLIII stereomicroscope (Leica Microsystems, Deerfield, IL) with bright-field transmitted light. All pictures were processed in ImageJ to measure the surface area and height of each lens for comparison. Immunohistochemical staining Immunohistochemical analysis was conducted as described previously [20]. Tissues were obtained from pancreatic cancer approximately 5 mm distant from the center of the implanted 125I seed. Formalin-fixed tissues were dehydrated, embedded in paraffin,

and sectioned. Tissue sections were deparaffinized, rehydrated, and incubated for 30 min in 0.3% hydrogen peroxide in methanol and then for 10 min with 1% goat serum in TBS. Then the sections were incubated with rabbit anti-human anti-DNMT1 antibody (Abcam), DNMT3a (Epitomics) and DNMT3b (Imagenex; all at 1:100) at room temperature overnight. After washing three times in TBS, the sections were incubated with biotinylated mouse Interleukin-3 receptor anti-rabbit IgG (1:5000; Abcam) for 30 min and followed by three 5 min wash in TBS. The final incubation was for 30 min with HRP-avidin D at 37°C. The peroxidase was detected with 0.05% 3,3-diaminobenzidine tetrahydrochloride (DAB). The sections were counterstained with hematoxylin and mounted in neutral gum medium for light microscopy [21]. Positive protein expression was visualized as nuclear localization of granular brown-yellow precipitate. The counts were performed in 3 high power fields of vision under a high magnification (400×) for each section.