Comparative investigations with synthetic N7-phenylguanine were carried out to clarify whether this compound is eliminated via the urine of rats as a benzene-derived nucleic acid adduct. As sensitive methods for detecting trace amounts of the compound, gas chromatography-mass spectroscopy, high performance liquid chromatography, and two immunoassays (enzyme-linked immunosorbent assay and fluoro...

The bursa of Fabricius (BF) is a target organ for various pathogenic microorganisms; however, the genes that regulate BF development and decline have not been fully characterized. Therefore, in this study, histological sections were obtained from black-boned chickens at 7 (N7), 42 (N42), 90 (N90) 120 days (N120) age, differential expression trends different stages analyzed by transcriptome anal...

Ranunculus circinatus Sibth. is a boreal, Eurasian species. The content of heavy metals and the composition fatty acids in R. circinatum from Delta Selenga River, which main tributary Lake Baikal, was studied for first time this paper. Plants river delta accumulated significant quantities, mostly Fe Mn, Pb Cd below detection limit. Palmitic C16:0, myristic C14:0 stearic C18:0 were saturated aci...

Hydrazine belongs to a group of compounds for which there is evidence that the in vivo genotoxic effects become manifest only upon exposure to toxic dose levels. The present study was performed to investigate whether this phenomenon is also reflected in the pattern of DNA methylation. The induction of N7- and O6-methylguanine (MeGua) was studied in liver DNA of rats, 16 hr after treatment with ...

Insight into the N7/O6 equatorial binding interactions of the antitumor active complex Rh(2)(OAc)(4)(H(2)O)(2) (OAc(-) = CH(3)CO(2)(-)) with the nucleotide 5'-GMP and the DNA fragment d(pGpG) has been obtained by one- (1D) and two-dimensional (2D) NMR spectroscopy. The lack of N7 protonation at low pH values and the significant increase in the acidity of N1-H (pK(a) approximately 5.6 as compare...

The N7/O6 equatorial binding interactions of the antitumor active complex Rh(2)(OAc)(4)(H(2)O)(2) (OAc(-) = CH(3)CO(2)(-)) with the DNA fragment d(GpG) have been unambiguously determined by NMR spectroscopy. Previous X-ray crystallographic determinations of the head-to-head (HH) and head-to-tail (HT) adducts of dirhodium tetraacetate with 9-ethylguanine (9-EtGH) revealed unprecedented bridging ...

the effects of allopurinol, acyclovir and theophylline on the activity of adenosine deaminase (ada) were studied in 50 mm sodium phosphate buffer ph 7.5 at 27°c, using a uv– vis spectrophotometer. adenosine deaminase is inhibited by these ligands, via different types of inhibition. allopurinol, as a transition state analog of xanthine oxidase, and acyclovir competitively inhibit the catalytic a...

The first polynomial-time algorithm to approximate (with arbitrary precision) the permanent of a non-negative matrix was presented by Jerrum, Sinclair and Vigoda. They designed a simulated annealing algorithm with a running time of O∗(n26) for 0/1 matrices. Subsequently, they improved their analysis, resulting in a O∗(n10) time algorithm. We present a O∗(n7) time algorithm. Our improvement come...

Nitrogen mustard anticancer drugs generate highly reactive aziridinium ions that alkylate DNA. Monoadducts arising from reaction with position N7 of guanine residues are the major DNA adducts generated by these agents. Interstrand cross-links in which the drug bridges position N7 of two guanine residues are formed in low yields relative to those of the monoadducts but are generally thought to b...

Styrene 7,8-oxide, which reacts preferentially at the N-7 position of guanine, yielded two pairs of diastereomers 7-(1'-hydroxy-2'-phenylethyl)-dGMP (the alpha-isomer) and 7-(2-hydroxy-2-phenylethyl)-dGMP (the beta-isomer) on reaction with deoxyguanosine-3'-monophosphate (3'-dGMP). The alpha- and beta-isomers were formed in the ratio 32:68. T4 polynucleotide kinase preferentially mediated label...