A major and previously undetected carcinogen-DNA adduct was found in the livers of rats given N,N-dimethylnitrosamine or 1,2-dimethylhydrazine. This adduct, which accounted for 55% of the total methyl residues in DNA at 72 hours after carcinogen treatment, was chromatographically identical to a synthetic purine ring-opened derivative of 7-methylguanine and could be released from the isolated he...

UDP-galactopyranose mutase (UGM) plays an essential role in galactofuranose biosynthesis in pathogens by catalyzing the conversion of UDP-galactopyranose to UDP-galactofuranose. Here we report the first crystal structure of a covalent intermediate in the UGM reaction. The 2.3 Å resolution structure reveals UDP bound in the active site and galactopyranose linked to the FAD through a covalent bon...

The apo structure of N5-carboxyaminoimidazole ribonucleotide synthase (PurK) from Bacillus anthracis (baPurK) with Mg2+ in the active site is reported at 1.96 Å resolution. PurK is an enzyme in the purine-biosynthetic pathway, unique to prokaryotes, that converts 5-aminoimidazole ribonucleotide to N5-carboxyaminoimidazole ribonucleotide and has been suggested as a potential antimicrobial drug t...

During listening to a musical piece, unexpected harmonies may evoke brain responses that are reflected electrically as an early right anterior negativity (ERAN) and a late frontal negativity (N5). In the present study we demonstrate that these components of the event-related potential can be evoked preattentively, that is, even when a musical stimulus is ignored. Both ERAN and N5 differed in am...

In a preceding paper of ours,1 it was reported that a marked decrease of N5,10methylenetetrahydrofolate reductase as well as a considerable decrease of N5 methyltetrahydrofolate transferase activity in the liver was found in riboflavin deficient rats. In the present study, chromatographic analysis followed by microbiologic assay of folate derivatives in the liver was made on rats with or withou...

BACKGROUND High-dose biotin therapy is beneficial in progressive multiple sclerosis (MS) and is expected to be adopted by a large number of patients. Biotin therapy leads to analytical interference in many immunoassays that utilize streptavidin-biotin capture techniques, yielding skewed results that can mimic various endocrine disorders. We aimed at exploring this interference, to be able to re...

BACKGROUND Experimental models are developed for the purpose of enhancing the understanding of the pathophysiological mechanisms involved in diabetes. Experimental findings lead to the development of treatment strategies to maintain metabolic conditions as close to normal as possible. There are several reports about streptozotocin induced mild diabetes to reproduce type 2 diabetes. However, stu...

The processing of covalent aflatoxin B1 (AFB1)-DNA adducts was investigated in confluent normal fibroblasts (NF) and xeroderma pigmentosum skin fibroblasts of Complementation Group A (XPA) following treatment with rat liver microsome-activated AFB1 for 30 min. Following rapid DNA isolation at slightly acidic pH by a new filter technique, more than 90% of the adducts corresponded to 2,3-dihydro-...

PURPOSE Divergence excess intermittent exotropia is thought to comprise 2 types of deviation, simulated and true. It is believed that simulated divergence excess is akin to a basic deviation but is controlled at near through accommodative and adaptive fusional vergences. While fixation target detail is known to influence accommodation and subsequently deviation size, no previous study has inves...