Helicobacter pylori-infected animal models are extremely suitable for the investigation of gastric carcinogenesis

Table 1 Duration of H pylori infection and number of point mutations in exon 5-8 of the p53 gene

Monkey	Durationof H pyloriinfection(yr)	Number of nucleotide(amino acid) substitutionsin p53				Atrophyscore1	Intensity of p53immunostaining2
		Ex 5	Ex 6	Ex 7	Ex 8		-
A	1.5	0(0)	2 (1)	0 (0)	1 (1)	2	-
B	2	4 (0)	2 (2)	5 (4)	4 (3)	3	+
C	3	4 (2)	1 (0)	2 (2)	2 (2)	4	+
D	3	2 (1)	1 (0)	1 (1)	4 (2)	5	+
E	3.5	5 (2)	2 (1)	5 (4)	6 (4)	4
F	4.5	5 (1)	3 (1)	4 (3)	5 (4)	6	-
G	5	4 (1)	3 (1)	2 (1)	8 (6)	8	+
H	7.5	8 (5)	2 (1)	5 (4)	8 (4)	12	++

¹, The atrophy score was calculated as the sum of the histological evaluations of five gastric specimens according to Updated Sydney System.

², The intensity of p53 immunostaining was classified into four grades: -, no staining; +, mild staining; ++, moderate staining; +++, intense staining.