Subtle Recognition of 14-Base Pair DNA Sequences via Threading Polyintercalation

ABSTRACT: Small molecules that bind DNA in a sequence-specific manner could act as antibiotic, antiviral, or anticancer agents because of their potential ability to manipulate gene expression. Our laboratory has developed threading poly-intercalators based on 1,4,5,8-naphthalene diimide (NDI) units connected in a head-to-tail fashion by flexible peptide linkers. Previously, a threading tetraintercalator composed of alternating minor−major−minor groove-binding modules was shown to bind specifically to a 14 bp DNA sequence with a dissociation half-life of 16 days [Holman, G. G., et al. (2011) Nat. Chem. 3, 875−881]. Herein are described new NDI-based tetraintercalators with a different major groove-binding module and a reversed N to C directionality of one of the minor groove-binding modules. DNase I footprinting and kinetic analyses revealed that these new tetraintercalators are able to discriminate, by as much as 30-fold, 14 bp DNA binding sites that differ by 1 or 2 bp. Relative affinities were found to correlate strongly with dissociation rates, while overall C2 symmetry in the DNA-binding molecule appeared to contribute to enhanced association rates

Development and Content Validity Testing of a Patient-Reported Treatment Acceptance Measure for Use in Patients Receiving Treatment via Subcutaneous Injection

AbstractBackgroundNew therapies in development for lowering low-density lipoprotein cholesterol, such as alirocumab, require administration by subcutaneous injections. There is a need to assess the acceptance of such treatments and their mode of administration.ObjectivesTo develop a novel patient-reported outcome measure, the Injection-Treatment Acceptance Questionnaire (I-TAQ), and assess its content validity using qualitative methods.MethodsConcepts generated from a literature and instrument review informed the initial drafting of 17 items in the I-TAQ, with item wording adapted from three existing instruments. Three rounds of qualitative interviews were conducted with 29 US-English speaking patients at high cardiovascular risk. Concept elicitation questioning was used to explore patients’ treatment experiences followed by cognitive debriefing of the I-TAQ using “think-aloud” methods. Verbatim transcripts were analyzed using thematic analysis.ResultsQualitative analysis of concept elicitation data identified the following relevant concepts: perceived efficacy, side effects, self-efficacy, convenience, and overall acceptance. Seven (24%) patients discussed an initial fear of needles, but described this as subsiding with no impact on adherence. Five items were added after round one interviews, three of which were retained after round two testing in which two further items were added, forming the conceptually comprehensive 22-item I-TAQ. Patients demonstrated good understanding of item wording, instructions, response scales, and recall period.ConclusionsSuccessive rounds of in-depth interviews resulted in a treatment acceptance measure with strong content validity. Pending demonstration of its psychometric properties, the I-TAQ may prove to be a valuable measure of patients’ perspectives toward being treated with low-density lipoprotein cholesterol–lowering therapies requiring subcutaneous injections

Effects of Policies Designed to Keep Firearms from High-Risk Individuals

This article summarizes and critiques available evidence from studies published between 1999 and August 2014 on the effects of policies designed to keep firearms from high-risk individuals in the United States. Some prohibitions for high-risk individuals (e.g., those under domestic violence restraining orders, violent misdemeanants) and procedures for checking for more types of prohibiting conditions are associated with lower rates of violence. Certain laws intended to prevent prohibited persons from accessing firearms -- rigorous permit-to-purchase, comprehensive background checks, strong regulation and oversight of gun dealers, and requiring gun owners to promptly report lost or stolen firearms -- are negatively associated with the diversion of guns to criminals. Future research is needed to examine whether these laws curtail nonlethal gun violence and whether the effects of expanding prohibiting conditions for firearm possession are modified by the presence of policies to prevent diversion