Browsing by Author "Allen, Heather"

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    Multi-dimensional analysis of oral cavity and oropharyngeal defects following cancer extirpation surgery, a cadaveric study
    (2018-04-24) Idris, Sherif; Mlynarek, Alex M; Ansari, Khalid; Harris, Jeffrey R; Rizk, Nabil; Cote, David; O’Connell, Daniel A; Allen, Heather; Dziegielewski, Peter; Seikaly, Hadi
    Abstract Background Defects following resection of tumors in the head and neck region are complex; more detailed and defect-specific reconstruction would likely result in better functional and cosmetic outcomes. The objectives of our study were: 1) to improve the understanding of the two- and three-dimensional nature of oral cavity and oropharyngeal defects following oncological resection and 2) to assess the geometric dimensions and the shapes of fasciocutaneous free flaps and locoregional tissue flaps required for reconstruction of these defects. Methods This study was an anatomic cadaveric study which involved creating defects in the oral cavity and oropharynx in two cadaveric specimens. Specifically, partial and total glossectomies, floor of mouth excisions, and base of tongue excisions were carried out. These subsites were subsequently geometrically analyzed and their volumes measured. The two-dimensional (2D) assessment of these three-dimensional (3D) structures included measures of surface area and assessment of tissue contours and shapes. Results The resected specimens all demonstrated unique dimensional geometry for the various anatomic sites. Using 2D analysis, hemiglossectomy defects revealed right triangle geometry, whereas total glossectomy geometry was a square. Finally, the base of tongue defects exhibited a trapezoid shape. Conclusions Customizing the geometry and dimensions of fasciocutaneous free flaps so that they are specific to the confronted head and neck defects will likely result in better functional and cosmetic outcomes.
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    The effect of silica desiccation under different storage conditions on filter-immobilized environmental DNA
    (2021-03-21) Allison, Michael J; Round, Jessica M; Bergman, Lauren C; Mirabzadeh, Ali; Allen, Heather; Weir, Aron; Helbing, Caren C
    Abstract Objective Silica gel beads have promise as a non-toxic, cost-effective, portable method for storing environmental DNA (eDNA) immobilized on filter membranes. Consequently, many ecological surveys are turning to silica bead filter desiccation rather than ethanol preservation. However, no systematic evaluation of silica bead storage conditions or duration past 1 week has been published. The present study evaluates the quality of filter-immobilized eDNA desiccated with silica gel under different storage conditions for over a year using targeted quantitative real-time polymerase chain reaction (qPCR)-based assays. Results While the detection of relatively abundant eDNA target was stable over 15 months from either ethanol- or silica gel-preserved filters at − 20 and 4 °C, silica gel out-performed ethanol preservation at 23 °C by preventing a progressive decrease in eDNA sample quality. Silica gel filter desiccation preserved low abundance eDNA equally well up to 1 month regardless of storage temperature (18, 4, or − 20 °C). However only storage at − 20 °C prevented a noticeable decrease in detectability at 5 and 12 months. The results indicate that brief storage of eDNA filters with silica gel beads up to 1 month can be successfully accomplished at a range of temperatures. However, longer-term storage should be at − 20 °C to maximize sample integrity.