A single residue unique to DinB-like proteins limits formation of the polymerase IV multiprotein complex in Escherichia coli.

The activity of DinB is governed by the formation of a multiprotein complex (MPC) with RecA and UmuD. We identified two highly conserved surface residues in DinB, cysteine 66 (C66) and proline 67 (P67). Mapping on the DinB tertiary structure suggests these are noncatalytic, and multiple-sequence alignments indicate that they are unique among DinB-like proteins. To investigate the role of the C66-containing surface in MPC formation, we constructed the dinB(C66A) derivative. We found that DinB(C66A) copurifies with its interacting partners, RecA and UmuD, to a greater extent than DinB. Notably, copurification of RecA with DinB is somewhat enhanced in the absence of UmuD and is further increased for DinB(C66A). In vitro pulldown assays also indicate that DinB(C66A) binds RecA and UmuD better than DinB. We note that the increased affinity of DinB(C66A) for UmuD is RecA dependent. Thus, the C66-containing binding surface appears to be critical to modulate interaction with UmuD, and particularly with RecA. Expression of dinB(C66A) from the chromosome resulted in detectable differences in dinB-dependent lesion bypass fidelity and homologous recombination. Study of this DinB derivative has revealed a key surface on DinB, which appears to modulate the strength of MPC binding, and has suggested a binding order of RecA and UmuD to DinB. These findings will ultimately permit the manipulation of these enzymes to deter bacterial antibiotic resistance acquisition and to gain insights into cancer development in humans.

Single-stage Composite Skin Reconstruction Using a Dermal Regeneration Template.

BACKGROUND: Composite reconstruction with a dermal substitute followed by skin graft is sometimes used for reconstructing high-quality skin while preserving donor sites. This often necessitates 2 separate procedures, additional general anesthetic, and longer hospitalization. Concurrent use of dermal substitutes and skin graft in a single stage has been previously reported in small series. Here, we report our experience with single-stage skin reconstruction with Integra and split-thickness skin graft for coverage of wounds post burn eschar excision and post burn scar contracture release. METHODS: This is a retrospective review of consecutive operations from 2013 to 2017 in which single-stage bilayer reconstruction (SSBR) was performed. Data were obtained from electronic medical records and perioperative photographs. RESULTS: In this 5-year period, 13 surgical sites were identified in which SSBR was used in 8 subjects. Average and median graft take was 86.2% and 95%, respectively. Graft take was over 90% in 10 out of 13 cases. One case required regrafting after initial graft failure. CONCLUSIONS: In the appropriate setting, SSBR is a practical technique in covering wounds post burn eschar excision and post burn scar contracture release resulting in reasonable graft take. Use of noncontaminated wound beds is crucial. Although there is risk of regrafting, it is not clear whether this risk is any higher than in split-thickness skin grafting alone. This study was unable to evaluate contribution of dermal substitute to contraction, function, and mobility, nor how hypothesized improvement of skin quality compares to the original thick dermal substitute. We recommend further investigation.

Palatal Motion After Primary and Secondary Furlow Palatoplasty.

Importance: Indications for Furlow palatoplasty include primary repair of cleft palate as well as secondary repair, or secondary palatoplasty for treatment of velopharyngeal insufficiency. Speculation exists surrounding the benefit of secondary Furlow palatoplasty in cases of a previously well-reconstructed palate or a short but otherwise anatomically normal soft palate because it has been theorized that reorientation of a previously reconstructed or normal muscular levator sling should in fact worsen palatal motion. Objective: To compare palatal motion following primary and secondary Furlow palatoplasty using footage from postoperative nasopharyngoscopy videos. Design, Setting, and Participants: In this retrospective case series, medical records in a database of an urban academic pediatric otolaryngology practice was used to identify patients who had undergone either primary or secondary Furlow palatoplasty. Subjects with adequate postoperative nasopharyngoscopy footage were randomized, and 2 blinded reviewers assessed soft palate motion in each video using an abbreviated version of the Golding-Kushner scale. Main Outcomes and Measures: Reviewers' blinded ratings of soft palate motion were quantified using a modified Golding-Kushner scale to generate a mean palatal motion score for each subject (range, 0.0-2.0). Scores of primary and secondary Furlow palatoplasty patients were compared. Results: Over a 4-year period, 20 patients with adequate postoperative nasopharyngoscopy footage were identified (12 primary Furlow palatoplasty patients and 8 secondary Furlow palatoplasty patients). Patients consisted of 8 males and 12 females and ranged in age from 12 months to 22 years at the time of postoperative nasopharyngoscopy. Modified Golding-Kushner scores were similar between groups: mean primary group, 1.61 (range, 0.5-2.0); mean secondary group, 1.53 (range, 0.75-2.0); absolute difference in mean, 0.08 (95% CI, 0.00-0.43); effect size, Hedges g, 0.18. There was fair interrater reliability (interclass coefficient, R = 0.45), consistent with prior reports using this scale. No significant difference in postoperative palatal motion scores was identified between primary and secondary palatoplasty groups in this study. Conclusions and Relevance: When examined in isolation, postoperative motion of the soft palate appears similar following both primary and secondary Furlow palatoplasty procedures, suggesting that there are no major deleterious effects on palatal motion following secondary Furlow palatoplasty.

An evaluation of plastic surgery resident selection factors.

OBJECTIVE: Our purpose was to provide a metric by which evaluation criteria are prioritized during resident selection. In this study, we assessed which residency applicant qualities are deemed important by members of the American Association of Plastic Surgeons (AAPS). METHODS: A survey was distributed to all 580 AAPS members, and 295 responded to rate the importance of resident metrics, including measures of competency and personal characteristics. Demographic information, background training, and interaction with residents were also noted. Using SAS v9.2 (SAS Institute, Cary, NC), outcomes were analyzed across demographic groups with column trend exact (CTE) test for ordinal variables, Mantel-Haenszel trend test for interval variables, and Fisher exact test for discrete variables. RESULTS: Regarding competency metrics, letters of recommendation from known sources is the most important factor, whereas letters from unknown sources ranks the lowest. Character evaluations identified honesty as the most desirable trait; dishonesty was the most despised. Across demographic groups, academic surgeons and program directors value letters from known sources more than nonacademicians or nonprogram directors (CTE p = 0.005 and 0.002, respectively). Academicians and current program directors regard research more highly than their counterparts do (CTE p = 0.022 and 0.022, respectively). Currently, practicing surgeons, academicians, and program directors value hard work more than others (CTE p = 0.008, 0.033, and 0.029, respectively). Program directors emphasize maturity and patient commitment and are less tolerant of narcissism (CTE p = 0.002, 0.005, and 0.003, respectively). Lastly, academic surgeons and program directors look more favorably upon strong team players (CTE p < 0.00001 and p = 0.008, respectively), but less so over time (Mantel-Haenszel trend p = 0.006). CONCLUSIONS: We have examined applicant metrics that were deemed important by AAPS members and assessed their demographic interpretation. We hope this article provides a framework for plastic surgery resident selection and a guide for applicants to ascertain which qualities are highly regarded by programs. Although these attributes are highly desirable, future studies could identify if they are predictive of successful and productive plastic surgery residencies and careers.

What Made Them Successful: An Introspective Survey of AAPS Members.

BACKGROUND: The purpose of this study is to assess which personal characteristics and external factors are important contributors to eventual success. METHODS: The authors distributed a survey to all members of the American Association of Plastic Surgeons and asked responders to rate the importance of 10 preselected qualities in contributing to their personal success. Survey outcomes were analyzed across different demographic groups. RESULTS: Of the 580 American Association of Plastic Surgeons members who were surveyed, 295 returned completed surveys. Overall analysis indicates that hard work, compassion, and manual dexterity are the 3 most important attributes. Many significant differences are observed across demographic groups, indicating potential biases among the survey responders. Notably, we find that male surgeons attribute mentorship to success much more so than female surgeons (Column Trend Exact [CTE], P = 0.021), whereas female surgeons are more likely to attribute their success to hard work (CTE, P = 0.023). Similarly, those who have been program directors credit their success to mentoring more so than nonprogram directors (CTE, P < 0.00001). The authors also found that senior surgeons, as measured by years in practice, place greater emphasis on mentoring and career opportunities than younger surgeons (Mantel-Haenszel Trend, P = 0.003 and 0.0009, respectively). It is also interesting to note that individual talent qualities tend to be favored by more senior surgeons and those with more distant ties to academia. CONCLUSION: The authors believe that recognizing the relative importance of such factors, and their associated biases, is essential for the process of selecting and developing future successful plastic surgeons.