Nouman Alvi

Learn More
S1 nuclease hydrolysis and bezoylated naphthoylated DEAE-cellulose (BND-cellulose) chromatography have been used to demonstrate that alkylation of DNA by dimethyl sulfate at neutral pH leads to the production of partially denatured molecules under conditions where no significant depurination occurs. DNA was alkylated with increasing concentrations of the(More)
In vitro experiments to study interaction of the mutagenic flavonoid quercetin with DNA are described. Calf thymus DNA treated with quercetin for various time periods was subjected to S1 nuclease hydrolysis. Thermal melting profiles of treated DNA were also determined using S1 nuclease. The rate of DNA hydrolyzed after 1 hr of pretreatment with quercetin(More)
Genotoxic damage in responsive mammalian cells is implicated as a critical event in the induction of apoptosis. We have evaluated the time course of activation of apoptosis in HL-60 cells following treatment with (+/-)-anti-BPDE metabolite, a well established DNA damaging carcinogen. Programmed cell death, determined by typical cellular and molecular(More)
We have used hydroxyapatite (HA) chromatography and S1 nuclease hydrolysis to study the modification in the secondary structure of DNA caused by certain intercalating and non-intercalating ligands. The principal conclusions of HA experiments were as follows: (1) when native DNA, complexed with drugs believed to bind to DNA by intercalation (ethidium(More)
Previous studies by others have shown that thiols, such as glutathione, cause cleavage of DNA in the presence of Cu(II) ions and that the hydroxyl radical derived from molecular oxygen is the major cleaving species. In this paper, we present several lines of evidence that strongly suggest that molecular oxygen is not essential for DNA cleavage and that(More)
The hypoxanthine guanine phosphoribosyltransferase (HPRT) gene is mutated by a variety of genotoxic agents in adult rat liver (ARL) epithelial cell lines. By polymerase chain reaction (PCR) amplification and DNA sequencing of rat ARL cell HPRT gene sequences with mouse- and rat-specific oligonucleotides, a large portion of the rat HPRT transcriptional(More)
S1 nuclease hydrolysis and benzoylated naphthoylated DEAE cellulose (BND-cellulose) chromatography have been used to study the effect of riboflavin and visible light on DNA. Native calf thymus DNA was incubated with riboflavin in the presence of fluorescent light for various time periods and subjected to S1 nuclease hydrolysis. An increasing degree of DNA(More)