Browsing by Author "Levinson, Howard"

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    A model of sequential heart and composite tissue allotransplant in rats.
    (Plast Reconstr Surg, 2010-07) Yang, Jun; Erdmann, Detlev; Chang, JC; Komatsu, Issei; Zhang, YiXin; Wang, DanRu; Hodavance, Michael S; Hollenbeck, Scott T; Levinson, Howard; Klitzman, Bruce; Levin, LS
    BACKGROUND: Some of the 600,000 patients with solid organ allotransplants need reconstruction with a composite tissue allotransplant, such as the hand, abdominal wall, or face. The aim of this study was to develop a rat model for assessing the effects of a secondary composite tissue allotransplant on a primary heart allotransplant. METHODS: Hearts of Wistar Kyoto rats were harvested and transplanted heterotopically to the neck of recipient Fisher 344 rats. The anastomoses were performed between the donor brachiocephalic artery and the recipient left common carotid artery, and between the donor pulmonary artery and the recipient external jugular vein. Recipients received cyclosporine A for 10 days only. Heart rate was assessed noninvasively. The sequential composite tissue allotransplant consisted of a 3 x 3-cm abdominal musculocutaneous flap harvested from Lewis rats and transplanted to the abdomen of the heart allotransplant recipients. The abdominal flap vessels were connected to the femoral vessels. No further immunosuppression was administered following the composite tissue allotransplant. Ten days after composite tissue allotransplantation, rejection of the heart and abdominal flap was assessed histologically. RESULTS: The rat survival rate of the two-stage transplant surgery was 80 percent. The transplanted heart rate decreased from 150 +/- 22 beats per minute immediately after transplant to 83 +/- 12 beats per minute on day 20 (10 days after stopping immunosuppression). CONCLUSIONS: This sequential allotransplant model is technically demanding. It will facilitate investigation of the effects of a secondary composite tissue allotransplant following primary solid organ transplantation and could be useful in developing future immunotherapeutic strategies.
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    A review of scar scales and scar measuring devices.
    (Eplasty, 2010-06-21) Fearmonti, Regina; Bond, Jennifer; Erdmann, Detlev; Levinson, Howard

    Objective

    Pathologic scarring affects millions of people worldwide. Quantitative and qualitative measurement modalities are needed to effectively evaluate and monitor treatments.

    Methods

    This article reviews the literature on available tools and existent assessment scales used to subjectively and objectively characterize scar.

    Results

    We describe the attributes and deficiencies of each tool and scale and highlight areas where further development is critical.

    Conclusion

    An optimal, universal scar scoring system is needed in order to better characterize, understand and treat pathologic scarring.
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    Application of Whole-Genome Sequencing to an Unusual Outbreak of Invasive Group A Streptococcal Disease.
    (Open Forum Infect Dis, 2016-01) Galloway-Peña, Jessica; Clement, Meredith E; Sharma Kuinkel, Batu K; Ruffin, Felicia; Flores, Anthony R; Levinson, Howard; Shelburne, Samuel A; Moore, Zack; Fowler, Vance G
    Whole-genome analysis was applied to investigate atypical point-source transmission of 2 invasive group A streptococcal (GAS) infections. Isolates were serotype M4, ST39, and genetically indistinguishable. Comparison with MGAS10750 revealed nonsynonymous polymorphisms in ropB and increased speB transcription. This study demonstrates the usefulness of whole-genome analyses for GAS outbreaks.
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    Characterization of the Foreign Body Response to Common Surgical Biomaterials in a Murine Model.
    (European journal of plastic surgery, 2017-11) Ibrahim, Mohamed; Bond, Jennifer; Medina, Manuel A; Chen, Lei; Quiles, Carlos; Kokosis, George; Bashirov, Latif; Klitzman, Bruce; Levinson, Howard
    BACKGROUND:Implanted biomaterials are subject to a significant reaction from the host, known as the foreign body response (FBR). We quantified the FBR to five materials following subcutaneous implantation in mice. MATERIALS AND METHODS:Polyvinyl alcohol (PVA) and silicone sheets are considered highly biocompatible biomaterials and were cut into 8mm-diameter disks. Expanded PTFE (ePTFE)and polypropylene are also widely used biocompatible biomaterials and were cut into 2cm-long cylinders. Cotton was selected as a negative control material that would invoke an intense FBR, was cut into disks and implanted. The implants were inserted subcutaneously into female C57BL/6 mice. On post-implantation days 14, 30, 60, 90 and 180, implants were retrieved. Cellularity was assessed with DAPI stain, collagen with Masson's trichrome stain. mast cells with toluidine-blue, macrophages with F4/80 immunohistochemical-stain, and capsular thickness and foreign body giant cells with hematoxylin & eosin. RESULTS:DAPI revealed a significantly increased cellularity in both PVA andsilicone, and ePTFE had the lowest cell density. Silicone showed the lowest cellularity at d14 and d90 whereas ePTFE showed the lowest cellularity at days 30, 60, and 180. Masson's trichrome staining demonstrated no apparent difference in collagen. Toluidine blue showed no differences in mast cells. There were, however, fewer macrophages associated with ePTFE. On d14, PVA had highest number of macrophages, whereas polypropylene had the highest number at all time points after d14. Giant cells increased earlier and gradually decreased later. On d90, PVA exhibited a significantly increased number of giant cells compared to polypropylene and silicone. Silicone consistently formed the thinnest capsule throughout all time points. On d14, cotton had formed the thickest capsule. On d30 polypropylenehas formed thickest capsule and on days 60, 90 and 180, PVA had formed thickest capsule. CONCLUSION:These data reveal differences in capsule thickness and cellular response in an implant-related manor, indicating that fibrotic reactions to biomaterials are implant specific and should be carefully considered when performing studies on fibrosis when biomaterials are being used.
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    Hardware Removal in Craniomaxillofacial Trauma: A Systematic Review of the Literature and Management Algorithm.
    (Annals of plastic surgery, 2015-11) Cahill, Thomas J; Gandhi, Rikesh; Allori, Alexander C; Marcus, Jeffrey R; Powers, David; Erdmann, Detlev; Hollenbeck, Scott T; Levinson, Howard

    Background

    Craniomaxillofacial (CMF) fractures are typically treated with open reduction and internal fixation. Open reduction and internal fixation can be complicated by hardware exposure or infection. The literature often does not differentiate between these 2 entities; so for this study, we have considered all hardware exposures as hardware infections. Approximately 5% of adults with CMF trauma are thought to develop hardware infections. Management consists of either removing the hardware versus leaving it in situ. The optimal approach has not been investigated. Thus, a systematic review of the literature was undertaken and a resultant evidence-based approach to the treatment and management of CMF hardware infections was devised.

    Materials and methods

    A comprehensive search of journal articles was performed in parallel using MEDLINE, Web of Science, and ScienceDirect electronic databases. Keywords and phrases used were maxillofacial injuries; facial bones; wounds and injuries; fracture fixation, internal; wound infection; and infection. Our search yielded 529 articles. To focus on CMF fractures with hardware infections, the full text of English-language articles was reviewed to identify articles focusing on the evaluation and management of infected hardware in CMF trauma. Each article's reference list was manually reviewed and citation analysis performed to identify articles missed by the search strategy. There were 259 articles that met the full inclusion criteria and form the basis of this systematic review. The articles were rated based on the level of evidence. There were 81 grade II articles included in the meta-analysis.

    Result

    Our meta-analysis revealed that 7503 patients were treated with hardware for CMF fractures in the 81 grade II articles. Hardware infection occurred in 510 (6.8%) of these patients. Of those infections, hardware removal occurred in 264 (51.8%) patients; hardware was left in place in 166 (32.6%) patients; and in 80 (15.6%) cases, there was no report as to hardware management. Finally, our review revealed that there were no reported differences in outcomes between groups.

    Conclusions

    Management of CMF hardware infections should be performed in a sequential and consistent manner to optimize outcome. An evidence-based algorithm for management of CMF hardware infections based on this critical review of the literature is presented and discussed.