Numerous mechanisms have evolved to control the accuracy of translation, including a recently discovered retrospective quality control mechanism in bacteria. This quality control mechanism is sensitive to perturbations in the codon:anticodon interaction in the P site of the ribosome that trigger a dramatic loss of fidelity in subsequent tRNA and release factor selection events in the A site. Th...

Lymphocytes from patients with various diseases associated with autoimmunity showed both impaired capacity to repair O6-methylguanine (a powerful, promutagenic, directly miscoding base lesion) and increased sensitivity to the cytocidal effects of cellular methylation by N-methyl-N-nitrosourea (MNU) compared with normal controls and patients with other disorders. Defective repair of O6-methylgua...

The methylhydrazines, monomethylhydrazine, 1,1-dimethylhydrazine, and 1,2-dimethylhydrazine, are known carcinogens but only weak mutagens in the Ames test. Chemical oxidation of these compounds by potassium ferricyanide greatly enhanced their mutagenicity to an Escherichia coli ada mutant and converted them into inducers of the adaptive response of E. coli to alkylation damage. Enzymatic oxidat...

Aminoglycoside antibiotics (Figs. 1 and 2), containing a unique polyamine/ carbohydrate structure, have attracted considerable attention because of their specific interactions with RNA. Their antibacterial activity is mainly exerted by their binding to the RNA of the bacterial ribosome, and thus interfering with the mRNA translation process. The miscoding causes membrane damage, which eventuall...

In vitro selection was used to define sequence contexts that significantly enhanced the mutagenic potential of 7, 8-dihydro-8-oxoguanine (8-oxoG). Contexts that simultaneously reduced the efficiency of 8-oxoG cleavage by formamidopyrimidine DNA N-glycosylase and increased the efficiency of misincorporating A opposite the lesion by DNA polymerase were isolated from a pool of 4(8) random octanucl...

Aminoglycoside antibiotics that bind to the ribosomal A site cause misreading of the genetic code and inhibit translocation. The clinically important aminoglycoside, gentamicin C, is a mixture of three components. Binding of each gentamicin component to the ribosome and to a model RNA oligonucleotide was studied biochemically and the structure of the RNA complexed to gentamicin C1a was solved u...

results are shown in Figure 1 of our article. Notably, of the MRSA-associated hospital discharges identified in UHC data, the percentage that did not include a MRSA infection decreased from 28% in 2004-2005 to 21% in 2006 and 19% in 2007. Thus, we did not see at our center an increase in the number of false-positive UHC-coded MRSA hospital discharges during 2004-2007, suggesting that the increa...

Abstract Background The change in subclassification of inflammatory bowel diseases (IBD) among patients with Crohn’s (CD), ulcerative colitis (UC), and IBD-unclassified (IBD-u) has previously been described subpopulations adult pediatric patients. To date, no large, multinational registries have characteristics who diagnosis. Methods We used the largest (27,628 individual for this study) prospe...