Table 2.

Malonaldehyde (MDA) content and aldehyde-protein adducts in homogenates of biopsy tissues from patients affected by colon adenocarcinoma at different stages of malignancy

Tumour stage	MDA content (nmol/mg protein)	MDA-protein adducts (AFU/mg protein) (390/460 nm ex/em)	HNE-protein adducts (AFU/mg protein) (355/460 nm ex/em)
Normal tissue (15)	0.67 (0.26)	23 (4.0)	30 (5.0)
T2 (5)	0.52 (0.44)	21 (4.0)	23 (3.4)*
T3 (8)	0.29 (0.17)**	16 (5.0)**	21 (2.4)**
T4 (2)	0.64 (0.17)	24 (7.0)	27 (4.5)

Values are mean (SD) (the number of specimens evaluated is indicated in parentheses).

Stage of tumour malignancy was evaluated following the TNM classification.

Significantly different from normal tissue: *p<0.05, **p<0.005.

Protein-aldehyde adducts were determined as fluorescence exhibited by interaction between protein amino functions and malonaldehyde (MDA) or 4-hydroxynonenal (HNE) at wavelengths of 390/460 nm and 355/460 nm, excitation/emission, respectively.

AFU, arbitrary fluorescence units.