Devin Miller

What Effect Does Self-Citation Have on Bibliometric Measures in Academic Plastic Surgery?

BackgroundResearch productivity plays a significant role in academic promotions. Currently, various bibliometric measures utilizing citation counts are used to judge an authors work. With increasing numbers of journals, numbers of open access publications, ease of online submission, and expedited indexing of accepted manuscripts, it is plausible that an author could influence his/her own bibliometric measures through self-citation. The purpose of this study was to determine the impact of self-citation in academic plastic surgery. MethodsA cohort of full-time academic plastic surgeons was identified from 9 U.S. plastic surgery training programs. For all included faculty, academic rank was retrieved from department/division websites, and bibliometric measures were assessed using a subscription bibliographic citation database (Scopus, Reed Elsevier, London, UK). Bibliometric measures included the Hirsch index (h-index, the number of publications h which are cited ≥ h times), total number of publications, and total number of citations. The h-index and total number of citations were collected with and without self-citations. Percent changes in the h-index and total citations were calculated after removal of self-citations and compared across academic ranks and levels of research productivity (total publications, h-index, and total citations). ResultsThe study cohort consisted of 169 full-time academic plastic surgeons. The h-index and total citations experienced decreases of 2.8 ± 5.0% (P < 0.0001) and 4.5 ± 4.6% (P < 0.0001), respectively, after correction for self-citation. More than half of the cohort (n = 113, 67%) did not experience a change in the h-index after removal of self-citations. These decreases did not vary across academic rank. Surgeons who self-cited at rates greater than 5% were 9.8 times more likely (95% confidence interval, 4.5–21.9; P < 0.001) to have their h-index change as a result of self-citation (after adjusting for academic rank). There were weak correlations between percent decreases in the h-index and total citations and various biblimoteric measures (total publications, h-index, total citations; r < 0.32). ConclusionsSelf-citation has a minor impact on common bibliometric measures in academic plastic surgery. The influence of self-citation is consistent across academic ranks and increasing levels of bibliometric measures, suggesting that authors are not manipulating the system with increasing experience.

Does the H Index Correlate With Academic Rank Among Full-Time Academic Craniofacial Surgeons?

OBJECTIVE To assess the relationship between the H index and the academic rank among full-time academic craniofacial surgeons. DESIGN This was a cross-sectional study of full-time academic craniofacial surgeons. SETTING Data were compiled and analyzed at the Department of Plastic and Reconstructive Surgery, Johns Hopkins Hospital. RESULTS The study sample included 127 full-time academic craniofacial surgeons. Overall, 89% were men, the mean number of years since completion of training was 16.2 ± 11.2 years. Most surgeons had a background in plastic and reconstructive surgery. Approximately 75% had completed formal fellowship training. The mean H index for the sample was 12.4 ± 9.9. The H index was strongly correlated with academic rank (rs = 0.62, p < 0.001). In a multiple linear regression model, adjusting for multiple confounders/effect modifiers, including number of years since training and total number of publications, the H index was significantly associated with academic rank (coefficient = 0.33, p = 0.04). CONCLUSIONS Among full-time academic craniofacial surgeons, the H index is strongly correlated with the academic rank.

A Novel Method for the Repair of Critically Sized Bone Defects: Utilization of a Muscle Derived Stem Cell-Seeded Scaffold Augments Proliferation, Migration and Osteogenic Induction.

PURPOSE: Contemporary surgical reconstruction of large craniofacial defects, commonly suffered during trauma and lifesaving decompressive craniectomies, has seen tremendous evolution with the development of custom alloplast implants and rigid fixation elements. Although these implants and fixation devices are often capable of providing coverage and stabilization to smaller or less complex defects, they remain prone to infection, extrusion, migration and failure with larger complicated wounds. Within this study, we aim to assess the functionality and osteo-inductive capacity of an easily deliverable osteo-enriched scaffold construct containing hBMP-2 and traceable muscle derived stem cells (MDSCs). We hope to determine a pragmatic regenerative application of this system to civilian and military patients suffering from complex craniofacial defects which current methods cannot address. METHODS: Utilizing a murine model, C57BL/6 (n=60) mice received two identical 5mm full-thickness craniectomy defects using a standardized micro-drill core bit. At 8 weeks, defects were imaged using a mini-CT, laser scanning confocal microscopy and tissues collected for downstream assays including: focused osteo-induction gene and proteome arrays. Concurrently, in vitro studies utilizing baclovirus Premo Fucci® transduced MDSCs (fluorescent correlation to cell cycle stage) were monitored using a FV10i-LIV® live cell confocal imaging system. Quantitative data was extracted from confocal multi-sequence 3D-imaging of daily and real-time cell migration assays as well as cell cycle proliferation kinetic studies. Additionally cell-to-cell interaction and correlative osteo-differentiation characteristics were analyzed following scaffold substrate and hBMP-2 variation.

Regeneration of Vascularized Corticocancellous Bone and Diploic Space Using Muscle-Derived Stem Cells: A Translational Biologic Alternative for Healing Critical Bone Defects

Background: Regeneration of functional bone substrate remains a priority in reconstructive surgery especially for patients suffering from complex skeletal defects. Efforts to develop implantable osteoinductive constructs and novel osteoconductive materials remain at the forefront of industry forces and product line development. Despite advancement in clinical practice and bone biology, cancellous autograft remains the gold standard for procedures requiring osteogenic mechanisms of healing. This study investigates the utility of muscle-derived stem cells as a cellular therapy for definitive bone regeneration through a form of neo-osteogenesis. Methods: Adipose-derived stem cell, bone marrow–derived mesenchymal stem cell, and muscle-derived stem cell populations were isolated separately from C57BL/6 murine tissues and supplemented with collagen scaffolding with or without bone morphogenetic protein-2 to compare relative osteogenic potency and ultrastructure organization in both two- and three-dimensional systems. Parallel populations were bound to a deployable collagen implant within a syngeneic murine cranial defect model. Results: Although all populations provided and maintained mesenchymal stem cell multilineage capacity, adipose-derived stem cell– and bone marrow–derived mesenchymal stem cell–enriched constructs were capable of forming small bone aggregates. Defects receiving muscle-derived stem cells self-assembled a form of organized corticocancellous structures within two- and three-dimensional in vitro systems and within the in vivo model. Muscle-derived stem cells also augmented healing, implant angiogenesis, and diploic space formation. Conclusion: Muscle-derived stem cell–enriched implants appear to provide an autologous response to current industry-derived products and an attractive alternative to mesenchymal stem cells for the regeneration of corticocancellous bone and a vascularized diploic space.

Desensitization and prevention of antibody-mediated rejection in vascularized composite allotransplantation by syngeneic hematopoietic stem cell transplantation

Background Candidates for vascularized composite allotransplantation (VCA) are frequently sensitized, putting them at risk for antibody-mediated rejection. Current desensitization strategies are imperfect and require a living-donor setting. Here we investigated the impact of sensitization on and the efficacy of a desensitization protocol utilizing syngeneic hematopoietic stem cell transplantation (HSCT) to prevent antibody-mediated rejection in VCA. Methods Skin transplants from Dark Agouti to Lewis rats were performed for sensitization. Orthotopic hind limb transplants from Dark Agouti donors were performed to sensitized and nonsensitized recipients, and the animals were treated with either daily tacrolimus or no immunosuppression. A desensitization protocol consisting of total body irradiation, fludarabine, and syngeneic HSCT was applied to sensitized animals. Graft rejection was monitored by clinical assessment and histological analysis. Serum levels of donor-specific antibodies (DSA IgG) were measured using flow cytometry. Results Sensitized recipients exhibited accelerated rejection by 5.5 ± 1.2 days without immunosuppression and 10.2 ± 3.6 days with daily tacrolimus compared with 8.7 ± 1.2 days and longer than 30 days in nonsensitized recipients, respectively. Serum levels of DSA IgG were markedly elevated (37.3 ± 3.34-fold from baseline) in sensitized recipients after VCA and correlated with histologic evidence of rejection and C4d deposition. Desensitization significantly reduced DSA compared with sensitized controls (2.6 ± 0.5-fold vs 6.0 ± 1.2-fold, P < 0.01) and along with daily tacrolimus led to improved VCA survival longer than 30 days without evidence of C4d deposition (n = 6). Conclusions In summary, sensitization leads to accelerated rejection of VCA, and syngeneic HSCT combined with conventional immunosuppression effectively reduces DSA and improves allograft survival in sensitized rats.

Optimal Murine Cranial Defect Reconstruction Utilizing a Novel Collagen Scaffold and rhBMP2 with Analysis Utilizing Confocal Microscopy.

MATERIALS AND METHODS: Patients treated between 2007 and 2015 with liposuction that had post-operative followup were reviewed. The diagnosis of the overgrowth condition was made by history, physical examination, and imaging. Patient gender, age, type of disease, location of enlargement, and morbidity were recorded. Outcome variables were improvement in patient symptoms, volume reduction, recurrence, and complications.

Costimulatory Blockade in Combination with Donor Bone Marrow Infusion Induces Immune Tolerance Across A Full MHC Barrier In A Translational Large Animal Vascularized Composite Allotransplantation Model

Fully MHCand gender mismatched MGH miniature swine underwent heterotopic hind-limb transplantation. Recipient animals received a short course of tacrolimus monotherapy, C/¡ donor BM infusion (60x10cells/kg), and CTLA4Ig (abatacept). Short course tacrolimus only and untreated animals served as controls. Chimerism was assessed by SRY-gene PCR analysis. Alloreactivity against donor antigens was assessed in vitro using CFSE-based Mixed Lymphocyte Reaction (CFSE-MLR) assays. Robust immune tolerance in vivo was assessed by secondary skin grafting. Tolerance maintenance upon allograft removal was tested in vitro by CFSE-MLR. Donor-specific antibodies (DSA) production was assessed using flow cytometry. Results