Clinician-targeted interventions to reduce antibiotic prescribing for acute respiratory infections in primary care:An overview of systematic reviews

This is the protocol for a review and there is no abstract. The objectives are as follows: To systematically review the literature and appraise the existing evidence from systematic reviews regarding the effects of interventions, aimed at changing clinician behaviour, to reduce antibiotic prescribing for ARIs in primary care

Clinical Sequencing Exploratory Research Consortium: Accelerating Evidence-Based Practice of Genomic Medicine

Despite rapid technical progress and demonstrable effectiveness for some types of diagnosis and therapy, much remains to be learned about clinical genome and exome sequencing (CGES) and its role within the practice of medicine. The Clinical Sequencing Exploratory Research (CSER) consortium includes 18 extramural research projects, one National Human Genome Research Institute (NHGRI) intramural project, and a coordinating center funded by the NHGRI and National Cancer Institute. The consortium is exploring analytic and clinical validity and utility, as well as the ethical, legal, and social implications of sequencing via multidisciplinary approaches; it has thus far recruited 5,577 participants across a spectrum of symptomatic and healthy children and adults by utilizing both germline and cancer sequencing. The CSER consortium is analyzing data and creating publically available procedures and tools related to participant preferences and consent, variant classification, disclosure and management of primary and secondary findings, health outcomes, and integration with electronic health records. Future research directions will refine measures of clinical utility of CGES in both germline and somatic testing, evaluate the use of CGES for screening in healthy individuals, explore the penetrance of pathogenic variants through extensive phenotyping, reduce discordances in public databases of genes and variants, examine social and ethnic disparities in the provision of genomics services, explore regulatory issues, and estimate the value and downstream costs of sequencing. The CSER consortium has established a shared community of research sites by using diverse approaches to pursue the evidence-based development of best practices in genomic medicine

The role of base flipping in damage recognition and catalysis by T4 endonuclease V

The process of moving a DNA base extrahelical (base flipping) has been shown in the co-crystal structure of a W-induced pyrimidine dimer-specific glycosylase, T4 endonuclease V, with its substrate DNA. Compared with other enzymes known to use base flipping, endonuclease V is unique in that it moves the base opposite the target site extrahelical, rather than moving the target base itself. Utilizing substrate analogs and catalytically inactive mutants of T4 endonuclease V, this study investigates the discrete steps involved in damage recognition by this DNA repair enzyme. Specifically, fluorescence spectroscopy analysis shows that fluorescence changes attributable to base flipping are specific for only the base directly opposite either abasic site analogs or the 5'-thymine of a pyrimidine dimer, and no changes are detected if the S-aminopurine is moved opposite the 3'-thymine of the pyrimidine dimer. Interestingly, base flipping is not detectable with every specific binding event suggesting that damage recognition can be achieved without base flipping. Thus, base flipping does not add to the stability of the specific enzyme-DNA complex but rather induces a conformational change to facilitate catalysis at the appropriate target site, When used in conjunction with structural information, these types of analyses can yield detailed mechanistic models and critical amino acid residues for extrahelical base movement as a mode of damage recognitionclos

Structural determinants for specific recognition by T4 endonuclease V

DNA glycosylases catalyze the scission of the N-glycosyl bond linking either a damaged or mismatched base to the DNA sugar phosphate backbone. T4 endonuclease V is a glycosylase/apurinic (AP) lyase that is specific for UV light-induced cis-syn pyrimidine dimers. As a proposed transition state analog/inhibitor for glycosylases, a phosphoramidite derivative containing a pyrrolidine residue has been synthesized. The binding of endonuclease V to this duplex was analyzed by gel mobility shift assays and resulted in a single stable complex of reduced mobility and an apparent K-d of 17 nM. To assess the importance of the positive charge for specific binding, studies using other non-cleavable substrate analogs were performed. Wild type T4 endonuclease V shows an g-fold decreased affinity for a tetrahydrofuran as compared with the pyrrolidine residue, demonstrating the significance of the positive charge for recognition. A S-fold increase in binding affinity for a reduced AP site was observed. Similar assays using catalytically compromised mutants (E23Q and E28D) of endonuclease V demonstrate altered affinities for the pyrrolidine as well as tetrahydrofuran and reduced AP sites. This approach has provided insight into the structural mechanism by which specific lesions are targeted by the protein as well as the structural determinants of the DNA required for specific recognition by T4 endonuclease V.clos