Validation of an Educational Tool for Skin Abscess Incision and Drainage by Delphi and Angoff Methods.

BACKGROUND: Bedside incision and drainage (I&D) of skin abscesses is a common medical procedure performed in a variety of medical settings. Yet, there is a paucity of published validated educational tools to teach and assess competency for this procedure. OBJECTIVE: To validate an educational tool to teach and assess competency for bedside I&D of skin abscesses via the Delphi consensus and Angoff standard setting methods. DESIGN: Expert consensus on the importance of each procedural step in the educational tool was obtained using the Delphi method, consisting of four rounds of iterative revisions based on input from a panel of experts. The passing cut-off score for a proficient provider was determined using the modified dichotomous Angoff method. PARTICIPANTS: All participants met the minimum criteria of active involvement in resident education and performance of at least 20 skin abscess I&D's within the past 5 years. Participant specialties included general surgery, emergency medicine, and internal medicine. MAIN MEASURES: The primary outcome was consensus on procedural steps and errors, defined as an interquartile range ≤ 2 on a 9-point Likert scale. A cut-off score was determined by the average across all respondents for the anticipated number of errors that would be committed by a provider with the level of proficiency defined in the survey. Qualitative input was incorporated into the educational tool. KEY RESULTS: At the end of four rounds of review via the Delphi process, participants achieved consensus on 93% of items on the clinical checklist and 85% of errors on the assessment checklist. Via the modified dichotomous Angoff method, the determined passing cut-off for competency was 6 out of 22 errors. CONCLUSION: An educational and evaluation tool for bedside I&D of skin abscesses was validated via the Delphi and Angoff methods.

Wdr68 requires nuclear access for craniofacial development.

Wdr68 is a highly conserved scaffolding protein required for craniofacial development and left-right asymmetry. A Ras-Map3k-Wdr68-Dyrk1 signaling relay may mediate these and other diverse signaling events important in development and disease. While the sub-cellular localization of Wdr68 has been shown to be dependent on that of its interaction partners, it is not clear where Wdr68 activity is required during development. Here we show that while a GFP-Wdr68 fusion functionally substituted for craniofacial development in the zebrafish, that a Nuclear Export Signal (NES) fusion protein (GFPNESWdr68) failed to support craniofacial development. As control for NES activity, we show that while GFP-Wdr68 exhibited a pan-cellular distribution in C2C12 cells, the GFPNESWdr68 fusion predominantly localized to the cell cytoplasm, as expected. Interestingly, while GFP-Wdr68 and RFP-Dyrk1a co-localized to the cell nucleus as expected based on the known sub-cellular localization for Dyrk1a, we found that the GFPNESWdr68 fusion redistributed RFP-Dyrk1a to the cell cytoplasm potentially disconnecting the Ras/Dyrk1 signal relay from further downstream targets. Consistent with a nuclear role in gene regulation, we also found that while a transcriptional activation domain fusion, CebpFlagWdr68, functionally substituted for endogenous Wdr68 for craniofacial development, that a transcriptional repression domain fusion, MadFlagWdr68, failed to support craniofacial development. Dyrk1b is required for myogenin (myog) expression in differentiating mouse C2C12 cells and here we report that wdr68 is also important for myog expression in differentiating C2C12 cells. Using a C2C12 cell myog promoter-reporter system, we found that Wdr68 overexpression increased reporter activity while moderate expression levels of MadFlagWdr68 interfered with reporter activity. Taken together, these findings support a nuclear role for Wdr68-containing complexes.

The zebrafish dyrk1b gene is important for endoderm formation.

Nodal-signaling is required for specification of mesoderm, endoderm, establishing left-right asymmetry, and craniofacial development. Wdr68 is a WD40-repeat domain-containing protein recently shown to be required for endothelin-1 (edn1) expression and subsequent lower jaw development. Previous reports detected the Wdr68 protein in multiprotein complexes containing mammalian members of the dual-specificity tyrosine-regulated kinase (dyrk) family. Here we describe the characterization of the zebrafish dyrk1b homolog. We report the detection of a physical interaction between Dyrk1b and Wdr68. We also found perturbations of nodal signaling in dyrk1b antisense morpholino knockdown (dyrk1b-MO) animals. Specifically, we found reduced expression of lft1 and lft2 (lft1/2) during gastrulation and a near complete loss of the later asymmetric lft1/2 expression domains. Although wdr68-MO animals did not display lft1/2 expression defects during gastrulation, they displayed a near complete loss of the later asymmetric lft1/2 expression domains. While expression of ndr1 was not substantially effected during gastrulation, ndr2 expression was moderately reduced in dyrk1b-MO animals. Analysis of additional downstream components of the nodal signaling pathway in dyrk1b-MO animals revealed modestly expanded expression of the dorsal axial mesoderm marker gsc while the pan-mesodermal marker bik was largely unaffected. The endodermal markers cas and sox17 were also moderately reduced in dyrk1b-MO animals. Notably, and similar to defects previously reported for wdr68 mutant animals, we also found reduced expression of the pharyngeal pouch marker edn1 in dyrk1b-MO animals. Taken together, these data reveal a role for dyrk1b in endoderm formation and craniofacial patterning in the zebrafish.