Implementation of an emergency department sign-out checklist improves transfer of information at shift change.

BACKGROUND: Transitions of care are ubiquitous in the emergency department (ED) and inevitably introduce the opportunity for errors. Few emergency medicine residency programs provide formal training or a standard process for patient handoffs. Checklists have been shown to be effective quality-improvement measures in inpatient settings and may be a feasible method to improve ED handoffs. OBJECTIVE: To determine if the use of a sign-out checklist improves the accuracy and efficiency of resident sign-out in the ED. METHODS: A prospective pre-/postinterventional study of residents rotating in the ED at a tertiary academic medical center. Trained research assistants observed resident sign-out during shift change over a 2-week period and completed a data collection tool to indicate whether or not key components of sign-out occurred and time to sign out each patient. An electronic sign-out checklist was implemented using a multi-faceted educational effort. A 2-week postintervention observation phase was conducted. Proportions, means, and nonparametric comparison tests were calculated using STATA. RESULTS: One hundred fifteen sign-outs were observed prior to checklist implementation and 114 were observed after. Significant improvements were seen in four sign-out components: reporting of history of present illness increased from 81% to 99%, ED course increased from 75% to 86%, likely diagnosis increased from 60% to 77%, and team awareness of plan increased from 21% to 41%. Use of the repeat-back technique decreased from 13% to 5% after checklist implementation and time to sign-out showed no significant change. CONCLUSION: Implementation of a checklist improved the transfer of information without increasing time to sign-out.

A top-five list for emergency medicine: a pilot project to improve the value of emergency care.

IMPORTANCE The mean cost of medical care in the United States is growing at an unsustainable rate; from 2003 through 2011, the cost for an emergency department (ED) visit rose 240%, from $560 to $1354. The diagnostic tests, treatments, and hospitalizations that emergency clinicians order result in significant costs. OBJECTIVE To create a "top-five" list of tests, treatments, and disposition decisions that are of little value, are amenable to standardization, and are actionable by emergency medicine clinicians. DESIGN, SETTING, AND PARTICIPANTS Modified Delphi consensus process and survey of 283 emergency medicine clinicians (physicians, physician assistants, and nurse practitioners) from 6 EDs. INTERVENTION We assembled a technical expert panel (TEP) and conducted a modified Delphi process to identify a top-five list using a 4-step process. In phase 1, we generated a list of low-value clinical decisions from TEP brainstorming and e-mail solicitation of clinicians. In phase 2, the TEP ranked items on contribution to cost, benefit to patients, and actionability by clinicians. In phase 3, we surveyed all ordering clinicians from the 6 EDs regarding distinct aspects of each item. In phase 4, the TEP voted for a final top-five list based on survey results and discussion. MAIN OUTCOMES AND MEASURES A top-five list for emergency medicine. The TEP ranked items on contribution to cost, benefit to patients, and actionability by clinicians. The survey asked clinicians to score items on the potential benefit or harm to patients and the provider actionability of each item. Voting and surveys used 5-point Likert scales. A Pearson interdomain correlation was used. RESULTS Phase 1 identified 64 low-value items. Phase 2 narrowed this list to 7 laboratory tests, 3 medications, 4 imaging studies, and 3 disposition decisions included in the phase 3 survey (71.0% response rate). All 17 items showed a significant positive correlation between benefit and actionability (r, 0.19-0.37 [P ≤ .01]). One item received unanimous TEP support, 4 received majority support, and 12 received at least 1 vote. CONCLUSIONS AND RELEVANCE Our TEP identified clinical actions that are of low value and within the control of ED health care providers. This method can be used to identify additional actionable targets of overuse in emergency medicine.

Aire employs a histone-binding module to mediate immunological tolerance, linking chromatin regulation with organ-specific autoimmunity.

Aire induces ectopic expression of peripheral tissue antigens (PTAs) in thymic medullary epithelial cells, which promotes immunological tolerance. Beginning with a broad screen of histone peptides, we demonstrate that the mechanism by which this single factor controls the transcription of thousands of genes involves recognition of the amino-terminal tail of histone H3, but not of other histones, by one of Aire's plant homeodomain (PHD) fingers. Certain posttranslational modifications of H3 tails, notably dimethylation or trimethylation at H3K4, abrogated binding by Aire, whereas others were tolerated. Similar PHD finger-H3 tail-binding properties were recently reported for BRAF-histone deacetylase complex 80 and DNA methyltransferase 3L; sequence alignment, molecular modeling, and biochemical analyses showed these factors and Aire to have structure-function relationships in common. In addition, certain PHD1 mutations underlying the polyendocrine disorder autoimmune polyendocrinopathy-candidiases-ectodermaldystrophy compromised Aire recognition of H3. In vitro binding assays demonstrated direct physical interaction between Aire and nucleosomes, which was in part buttressed by its affinity to DNA. In vivo Aire interactions with chromosomal regions depleted of H3K4me3 were dependent on its H3 tail-binding activity, and this binding was necessary but not sufficient for the up-regulation of genes encoding PTAs. Thus, Aire's activity as a histone-binding module mediates the thymic display of PTAs that promotes self-tolerance and prevents organ-specific autoimmunity.

The plant homeodomain finger of RAG2 recognizes histone H3 methylated at both lysine-4 and arginine-2.

Recombination activating gene (RAG) 1 and RAG2 together catalyze V(D)J gene rearrangement in lymphocytes as the first step in the assembly and maturation of antigen receptors. RAG2 contains a plant homeodomain (PHD) near its C terminus (RAG2-PHD) that recognizes histone H3 methylated at lysine 4 (H3K4me) and influences V(D)J recombination. We report here crystal structures of RAG2-PHD alone and complexed with five modified H3 peptides. Two aspects of RAG2-PHD are unique. First, in the absence of the modified peptide, a peptide N-terminal to RAG2-PHD occupies the substrate-binding site, which may reflect an autoregulatory mechanism. Second, in contrast to other H3K4me3-binding PHD domains, RAG2-PHD substitutes a carboxylate that interacts with arginine 2 (R2) with a Tyr, resulting in binding to H3K4me3 that is enhanced rather than inhibited by dimethylation of R2. Five residues involved in histone H3 recognition were found mutated in severe combined immunodeficiency (SCID) patients. Disruption of the RAG2-PHD structure appears to lead to the absence of T and B lymphocytes, whereas failure to bind H3K4me3 is linked to Omenn Syndrome. This work provides a molecular basis for chromatin-dependent gene recombination and presents a single protein domain that simultaneously recognizes two distinct histone modifications, revealing added complexity in the read-out of combinatorial histone modifications.

RAG2 PHD finger couples histone H3 lysine 4 trimethylation with V(D)J recombination.

Nuclear processes such as transcription, DNA replication and recombination are dynamically regulated by chromatin structure. Eukaryotic transcription is known to be regulated by chromatin-associated proteins containing conserved protein domains that specifically recognize distinct covalent post-translational modifications on histones. However, it has been unclear whether similar mechanisms are involved in mammalian DNA recombination. Here we show that RAG2--an essential component of the RAG1/2 V(D)J recombinase, which mediates antigen-receptor gene assembly--contains a plant homeodomain (PHD) finger that specifically recognizes histone H3 trimethylated at lysine 4 (H3K4me3). The high-resolution crystal structure of the mouse RAG2 PHD finger bound to H3K4me3 reveals the molecular basis of H3K4me3-recognition by RAG2. Mutations that abrogate RAG2's recognition of H3K4me3 severely impair V(D)J recombination in vivo. Reducing the level of H3K4me3 similarly leads to a decrease in V(D)J recombination in vivo. Notably, a conserved tryptophan residue (W453) that constitutes a key structural component of the K4me3-binding surface and is essential for RAG2's recognition of H3K4me3 is mutated in patients with immunodeficiency syndromes. Together, our results identify a new function for histone methylation in mammalian DNA recombination. Furthermore, our results provide the first evidence indicating that disrupting the read-out of histone modifications can cause an inherited human disease.

ING2 PHD domain links histone H3 lysine 4 methylation to active gene repression.

Dynamic regulation of diverse nuclear processes is intimately linked to covalent modifications of chromatin. Much attention has focused on methylation at lysine 4 of histone H3 (H3K4), owing to its association with euchromatic genomic regions. H3K4 can be mono-, di- or tri-methylated. Trimethylated H3K4 (H3K4me3) is preferentially detected at active genes, and is proposed to promote gene expression through recognition by transcription-activating effector molecules. Here we identify a novel class of methylated H3K4 effector domains--the PHD domains of the ING (for inhibitor of growth) family of tumour suppressor proteins. The ING PHD domains are specific and highly robust binding modules for H3K4me3 and H3K4me2. ING2, a native subunit of a repressive mSin3a-HDAC1 histone deacetylase complex, binds with high affinity to the trimethylated species. In response to DNA damage, recognition of H3K4me3 by the ING2 PHD domain stabilizes the mSin3a-HDAC1 complex at the promoters of proliferation genes. This pathway constitutes a new mechanism by which H3K4me3 functions in active gene repression. Furthermore, ING2 modulates cellular responses to genotoxic insults, and these functions are critically dependent on ING2 interaction with H3K4me3. Together, our findings establish a pivotal role for trimethylation of H3K4 in gene repression and, potentially, tumour suppressor mechanisms.