5- aminolevulinic acid induces single-straqnd breaks in plasmid pbr322 dna in the presence of 'FE POT.2+' ions - Onuki, J; Medeiros, Marisa Helena Gennari de; Bechara, Etelvino José Henriques; Di Mascio, Paolo (Biochimica et Biophysica Acta, 1994)