Showing papers in "Chemico-Biological Interactions in 1971"

TL;DR: No conclusive evidence was found to establish whether N-oxides were intermediate in the formation of pyrrole derivatives, however, pyrrolic derivatives could not be detected when N- oxides were added to the hepatic microsomal system in vitro, and the more toxic alkaloids were hepatotoxic.

TL;DR: In hamster cells the effect of alkylation by MNNG and MNU was essentially the same as that by MMS, which supported the concept of a common mechanism of action for these three compounds in this cell line.

TL;DR: Non-semiconservative DNA synthesis was followed in hamster and HeLa cells after treatment with various concentrations of N-methyl- and N-ethyl-N′-nitro-N-nitrosoguanidine, N- methyl and ethyl methanesulphonate and mustard gas to provide supporting evidence that ‘repair synthesis’ was related to the initial alkylated DNA and was not a non-specific response to cellular alkylation.

TL;DR: The specific activities of ATPases in homogenates of bluegill fish tissues were determined and found to be similar to those previously reported for rabbit tissues, with Na+-K+ ATPase was most active in brain and kidney, and Mg2+ ATP enzyme was mostactive in muscle.

TL;DR: A selective survey has been made of the current literature on singlet oxygen concentrating on the involvement of this species in the aforementioned processes.

TL;DR: Synchronous HeLa cells treated with low concentrations of MNU prior to the onset of DNA synthesis are not delayed in their entry into the DNA synthetic phase (S), and cells similarly treated in the S phase are also unaffected with respect to DNA synthesis or cell progression.

TL;DR: Sedimentation analysis in Dextran gradients of subcellular fractions of 3T3 cells exposed to [3H]PMA demonstrated that the bulk of bound label was associated with a Na+-K+ ATPase-rich protein peak which has the properties of cell membranes.

TL;DR: The binding of AABP and ABP to rat-liver ribosomal RNA and DNA in vivo was studied and the large difference in reactivity between N-hydroxy-AF and N-Hydroxy-ABP as well as the pH-dependence of the reactions were confirmed.

TL;DR: The examination of new substituted phenyl-1-aziridines confirm the highly specific structural requirements for activity and indicate that there is an optimum value for each of these parameters for maximum biological activity.

TL;DR: This kind of interaction with DNA, which may be causally related to the mechanism of DMBA-induced oncogenesis, does not appear to require prior metabolic activation of the agent.

TL;DR: It is proposed that additional damage is introduced into methylated DNA during its replication and this causes subsequent inhibition of DNA synthesis in hamster cells, by a mechanism which is probably associated with the delay in onset of S.

TL;DR: The digestion of microsomal membranes (from rat liver) with purified phospholipase A or C was found to increase severalfold the measurable UDP glucuronyltransferase activity in the membranes without solubilizing the enzyme.

TL;DR: Phosphatidylcholine, which is required for fatty acid, hydrocarbon and drug hydroxylation in a reconstituted liver microsomal enzyme system, is essential for the enzymatic reduction of cytochrome P-450.

TL;DR: It is shown that methyl methanesulphonate (MMS) does not produce O -(6)-methylguanine from deoxyguanosine, and in the present study it failed to induce thymic lymphomas or pulmonary adenomas in inbred Swiss mice.

TL;DR: The rates of hydrolysis of several aromatic nitrogen mustards have been determined in the presence of proteins and of synthetic and semisynthetic polymeric substances, and only those molecules with extensive hydrophobic areas significantly slowed down the hydrolyzing of the alkylating agents.

TL;DR: In this paper, the authors show that DNA synthesis is insensitive to HU which continues for a considerable time after exposure to the drug, and that at a 5% survival level all of the DNA repaired after MMS treatment replicates or is excised within 24 hours.

TL;DR: Some amino acids, bases of nucleic acids, and gibberellic acid partially alleviated the alantolactone-induced inhibition of the seed germination.

TL;DR: Male Leeds strain rats were fed a diet containing 0.05% of 2-acetylaminofluorene for 8–10 months and liver tissue was examined, showing changes in cell surface morphology, depletion and redisposition of the granular endoplasmic reticulum, hypertrophy of the agranularendoplasmo-reticulum and reduced mitochondrial size.

TL;DR: Proton magnetic resonance (PMR) spectroscopy showed the formation of a specific ternary complex composed of l -adrenaline, ATP and Co 2+ at pH 5.5 ± 0.5, considered to be evidence for theformation of a ternARY complex involving l-adrenalin, Mg 2+ and ATP.