FIGURES AND TABLES

Figure 1.

Treatment effects upon MTCRII. (A) Total MT-immunopositive crypt number per 10⁴ crypts in each treatment group. Significant between-group treatment differences were observed (P<0.01). The Duncan post hoc test identified three distinct homogeneous treatment subsets (A–C), showing significant incremental differences in total mutation load: (A) Groups 1–4, distilled water, DMSO or CgN only (1 and 4%); (B) Groups 5 and 6, MNU only or MNU and one 7 day cycle of 1% CgN; (C) Groups 8 and 11, MNU and three 7 day cycles of 1% CgN or MNU and continuous 4% CgN. Groups 7, 9 and 10 overlapped subsets B and C. (B) Formation of patches of 2 contiguous MT immunopositive crypts in each treatment group. The Duncan posthoc test identified three distinct homogeneous treatment subsets (A–C), showing significant incremental differences in mutant (MT immunopositive) patch formation: (A) Groups 1–4, Distilled water, DMSO or CgN only (1 and 4%); (B) Group 5, MNU alone; (C) Groups 7 and 9, MNU and one or three 7 day cycles of 4% CgN. Groups 6, 8, 10 and 11 overlapped subsets B and C. (C) Large MT immunopositive patch. An example of a large patch comprising 5 MT immunopositive crypts, from a combined CgN/MNU treatment group.

Figure 2.

Treatment effects on ACF. (A) Effects of treatment regimens on ACF number in murine colon. One-way analysis of variance demonstrated significant between-group differences in numbers of ACF per 10⁴ colonic crypts (P<0.001). The Duncan post hoc test identified 5 homogeneous treatment subsets (A–E), showing significant incremental differences in frequency of ACF formation: (A) Groups 1–4, Distilled water, DMSO or CgN only (1 and 4%); (B) Group 5, MNU alone; (C) Groups 6 and 7, MNU and one 7 day cycle of 1 or 4% CgN; (D) Group 8, MNU and three 7-day cycles of 1% CgN; (E) Groups 9 and 11, MNU and either three 7-day cycles of 4% CgN or continuous 4% CgN. These subsets showed significant incremental differences of mean ACF per 10⁴ colonic crypts. Group 10 (MNU and 3 7-day cycles of 4% CgN) overlapped subsets C and D. (B) Effects of treatment regimens on size of ACF (crypt multiplicity). One-way analysis of variance demonstrated significant between-group differences in numbers of aberrant crypts per focus {crypt multiplicity} (P<0.01). The Duncan post hoc test identified 5 homogeneous treatment subsets (A–E), showing significant incremental differences in crypt multiplicity: (A) groups 1 and 2, distilled water alone or DMSO alone; (B) groups 3 and 4, continuous treatment with 1 or 4% CgN alone; (C) groups 5 and 6, MNU alone or MNU and 1 7-day cycle of 1% CgN; (D) groups 9 and 11, MNU and either 3 7-day cycles of 4% CgN or continuous 4% CgN; (E) group 8, MNU and three 7-day cycles of 1% CgN. Groups 7 and 10 (MNU and 1 7-day cycle of 4% CgN or continuous 1% CgN) overlapped subsets D and E.

Figure 3.

Correlations between MTCRII and ACF. (A) Total MT-immunopositive crypt number vs number of ACF per 10⁴ crypts. Correlation between total MT-immunopositive crypt number and ACF per 10⁴ crypts in all treatment groups (r=0.732; P<0.01 by Pearson's product moment test). (B) Total MT-immunopositive crypt number vs size of ACF. Correlation between total MT-immunopositive crypt number per 10⁴ crypts and ACF size in all treatment groups (r=0.84; P<0.01 by Pearson's product moment test).

Table 1 - Effects of 20-week treatments on group fluid and food consumption and weight index.

Table 2 - Treatment effects upon MTCRII.