The cyano-substituted quinoxaline di-N-oxide (2) is a potential antitumor agent, which selectively kills hypoxic cells. While investigating this drug's potential ability to act as a surrogate for O(2) in DNA damage processes, we discovered that 2 produces alkali-labile lesions selectively at 2'-deoxyguanosine positions upon irradiation in the UV-A (lambda(max) = 350 nm) region. Strand damage is...

BACKGROUND Depressive disorder (DD), including recurrent DD (rDD), is a severe psychological disease, which affects a large percentage of the world population. Although pathogenesis of the disease is not known, a growing body of evidence shows that inflammation together with oxidative stress may contribute to development of DD. Since reactive oxygen species produced during stress may damage DNA...

Intermediatry steps in cellulose synthesis in Acetobacter xylinum were studied with resting cells and particulate-membranous preparations of the wild-type strain and of a celluloseless mutant. Exogenously supplied [1-14C]glucose was rapidly converted by resting cells of both types into glucose 6-phosphate, glucose 1-phosphate, and uridine glucose 5'-diphosphate (UDP)-glucose and incorporated in...

Bleomycin-induced breakage of an isolated covalently closed circular DMA from bacteriophage PM2 was as sayed fluorometrically after agarose gel electrophoresis and staining with ethidium bromide. When bleomycindamaged DMA was assayed under neutral conditions, there was a decrease in the amount of Form I DMA and a simultaneous increase in both Forms II and III of DMA. However, when the damage wa...

Glassy samples with a composition of 40P2O5&ndash;30V2O5&ndash;(30-x)Li2O&ndash; xK2O, 0<x<30 (mol %) were prepared by the conventional melt quenching technique in two forms of bulk and blown film. X-ray diffraction patterns corroborated the amorphous feature of the samples. Density of samples was investigated by using Archimedes principle. Based on absorption and reflection spectra, indirect a...

The ability of neocarzinostatin (NCS) chromophore to damage DNA, as manifested by strand breaks and base release, is markedly decreased under anaerobic conditions but can be restored by nitroaromatic radiation sensitizers, which by themselves have no effect. The effectiveness of these compounds is correlated with their electron affinity as measured by their one-electron reduction potentials and...

Biogeosciences Discussions is the access reviewed discussion forum of Biogeosciences Availability of phosphate for phytoplankton and bacteria and of labile organic carbon for bacteria at different pCO2 levels in a mesocosm study T. Tanaka, T. F. Thingstad, T. Løvdal, H.-P. Grossart, A. Larsen, K. G. Schulz, and U. Riebesell Marine Microbiology Res. Group (MMRG), Dept. of Biology, Univ. Bergen, ...

In a previous paper (1) evidence was given to show that inorganic phosphate is esterified when succinate is incubated aerobically with cell-free extracts of Escherichia coli in the presence of inorganic phosphate. Based upon residual succinate determinations and upon the theoretical oxygen uptake for oxidation to fumarate, the data have been interpreted to mean that phosphorylation of inorganic...

Synthesis of a large number of simple and complex polymetaphosphate glasses of alkali metals with the general formulae (MXM1 -X)P03)fl and (MM_12PO3) has been described, where M and M' = Li,Na, K, Rb or Cs; M" = Be, Mg,Ca,Sr,Ba,Zn,Cd,Pb,CuorNi;andx = 1,,4or4.Thepreparations have been carried out by heating alkali dihydrogen phosphate, metal oxide (or carbonate) and diammonium hydrogen phosphate...