The reaction products formed by reacting deoxyguanosine with phosphoramide mustard at pH 7.4 have been analyzed by high-performance liquid chromatography and Schiff's reaction. The adducts consisted of five fractions of phosphoramide mustard-imidazole ring-opened deoxyguanosine complexes and one fraction of each of intact phosphoramide mustard-deoxyguanosine and phosphoramide mustard-dideoxygua...

The mechanism by which 2'-deoxyguanosine is toxic for lymphoid cells is relevant both to the severe cellular immune defect of inherited purine nucleoside phosphorylase (PNP) deficiency and to attempts to exploit PNP inhibitors therapeutically. We have studied the cell cycle and biochemical effects of 2'-deoxyguanosine in human lymphoblasts using the PNP inhibitor 8-aminoguanosine. We show that ...

Newborns with a genetic deficiency of purine nucleoside phosphorylase (PNP) are normal, but exhibit a specific T-cell immunodeficiency during the first years of development. All other cell and organ systems remain functional. The biological significance of human PNP is degradation of deoxyguanosine, and apoptosis of T-cells occurs as a consequence of the accumulation of deoxyguanosine in the ci...

Exposure of amino acids, peptides and proteins to radicals, in the presence of oxygen, gives high yields of hydroperoxides. These materials are readily decomposed by transition metal ions to give further radicals. We hypothesized that hydroperoxide formation on nuclear proteins, and subsequent decomposition of these hydroperoxides to radicals, might result in oxidative damage to associated DNA....

Deoxyguanosine is selectively cytotoxic to leukemic cells from patients with T-acute lymphoblastic leukemia (T-ALL), whereas all other leukemic cell types were significantly less sensitive. Arabinosylguanine, a deoxyguanosine analog resistant to cleavage by purine nucleoside phosphorylase, is a more potent inhibitor of DNA synthesis in T-leukemic cells than deoxyguanosine and retains a selectiv...

The aim of this study is to determine the changes in serum levels malondialdehyde and 8-hydroxy-2'-deoxyguanosine, as indicators oxidative stress, response periodontal treatment adyuvanted with topical doxycycline. Methods: Thirty four patients disease were studied (DOX group n=16; Control n=18), determining 8-hydroxy-2'-deoxyguanosine urine at baseline three months after non-surgical treatment...

Male Sprague-Dawley rats were exposed to conditioned emotional stimuli in a communication box, which is much more psychologically conditioned stress than the commonly used restraint and water immersion, to investigate the induction of oxidative DNA damage by psychological stress. Significantly higher levels of 8-hydroxy-2'-deoxyguanosine in rat liver nuclear DNA than in the controls [1.46 +/- 0...

The reaction in ether-methanol between 2'-deoxyguanosine and diazomethane or its ethyl or n-butyl homologue gives 1-, O(6)- and 7-alkyl-2'-deoxyguanosine. N(2),O(6)-Dimethyl-2'-deoxyguanosine was also detected. The hydrolysis of the methyl and the ethyl derivatives gives the corresponding alkylguanines: the O(6)-alkyl-2'-deoxyguanosines were sequentially hydrolysed, first to 2-amino-6-alkoxypur...

The mode of action of the antiproliferative nucleoside analogue 2,6diaminopurinedeoxyriboside (DAPdR) has been characterized in cultured 11210 cells. A marked concentration-dependent decrease in DNA syn thesis and ribonucleotide reductase activity occurred in LI 210 cells exposed to 0.05 to 1.0 HIM DAPdR. Concomitantly, dGTP levels in creased as much as 1100-fold as compared to untreated contro...

Several mechanisms regarding the adverse health effects of nanomaterials have been proposed. Among them, oxidative stress is considered to be one of the most important. Many in vitro studies have shown that nanoparticles generate reactive oxygen species, deplete endogenous antioxidants, alter mitochondrial function and produce oxidative damage in DNA. 8-Hydroxy-2'-deoxyguanosine is a major type...