Arhana Chattopadhyay

Burns resulting from spontaneous combustion of electronic cigarettes: a case series

BackgroundElectronic cigarette (e-cigarette) sales have grown rapidly in recent years, coinciding with a public perception that they are a safer alternative to traditional cigarettes. However, there have been numerous media reports of fires associated with e-cigarette spontaneous combustion.Case PresentationThree severe burns caused by spontaneous combustion of e-cigarettes within a 6-month period were treated at the Santa Clara Valley Medical Center Burn Unit. Patients sustained partial and full-thickness burns. Two required hospitalization and surgical treatment.ConclusionsE-cigarettes are dangerous devices and have the potential to cause significant burns. Consumers and the general public should be made aware of these life-threatening devices.

Characteristics of Reconstituted Lyophilized Tendon Hydrogel: An Injectable Scaffold for Tendon Regeneration

Background: The authors have developed a tendon hydrogel that may be injected into the site of tendon injury to improve speed and strength of repair. The aim of this study was to compare the biological and physical properties of fresh, hydrated tendon hydrogel with its reconstituted lyophilized counterpart with the goal of increasing clinical feasibility. Materials: Hydrogel was prepared from fresh human cadaveric flexor tendon. Fresh gel was compared to gel aliquots that were lyophilized and reconstituted with sterile deionized water. Scanning electron microscopy was used to examine the microarchitecture of gelated samples. Rat adipose-derived stem cells were seeded in hydrogel, and cell viability was assessed after 7 days. MTS colorimetric assay was used to evaluate both the effect of prolonged storage on gel and the ability of reconstituted lyophilized hydrogel to activate platelet-rich plasma. The viability and proliferation of luciferase-transfected adipose-derived stem cells embedded within hydrogel in vivo was assessed by a bioluminescence in vivo imaging system. Results: Reconstituted lyophilized hydrogel demonstrated similar handling properties compared to fresh gel. Adipose-derived stem cells remained viable 7 days after reseeding in both conditions. Lyophilized hydrogel retained its ability to activate platelet-rich plasma and retained 95 percent of its maximal proliferative capacity at 30 days. The in vivo imaging system demonstrated similar cell proliferation, with signal persisting through day 13. Conclusions: Reconstitution of lyophilized hydrogel stimulated cell proliferation and platelet-rich plasma activation to a greater degree than did fresh hydrogel. Efficacy after prolonged storage was also shown to be superior. Therefore, this lyophilized formulation of tendon hydrogel may have wider clinical applicability.

Principles of tendon reconstruction following complex trauma of the upper limb.

Reconstruction of tendons following complex trauma to the upper limb presents unique clinical and research challenges. In this article, the authors review the principles guiding preoperative assessment, surgical reconstruction, and postoperative rehabilitation and management of the upper extremity. Tissue engineering approaches to address tissue shortages for tendon reconstruction are also discussed.

The Tissue-engineered Tendon-bone Interface: In Vitro and In Vivo Synergistic Effects of Adipose-derived Stem Cells, Platelet-rich Plasma, and Extracellular Matrix Hydrogel

Background: Suboptimal healing of the tendon-bone interface remains an unsolved problem. The authors hypothesized that (1) platelet-rich plasma and prolonged in vitro incubation will produce interface scaffolds with greater reseeding of viable adipose-derived stem cells; and (2) when implanted with extracellular matrix hydrogel, constructs will display superior in vivo strength repair and biocompatibility. Methods: Achilles-calcaneal composite tendon-bone interface scaffold grafts were harvested from 30 Wistar rats. After physicochemical decellularization and lyophilization, scaffolds were revitalized in rat plasma or 100% activated rat platelet-rich plasma and reseeded with viable adipose-derived stem cells. For part 2 of the study, 90 Sprague-Dawley rats underwent reconstruction with one of five decellularized, lyophilized scaffold revitalization/reseeding conditions: (1) phosphate-buffered saline; (2) lyophilized, 100% activated platelet-rich plasma; (3) platelet-rich plasma and extracellular matrix hydrogel; (4) platelet-rich plasma and 14-day reseeding with ASC-luc2-eGFP cells; and (5) plasma, reseeding, and hydrogel. Results: In part 1, platelet-rich plasma–revitalized grafts demonstrated greater live viable adipose-derived stem cell loads at 3, 7, and 14 days and total adipose-derived stem cell loads at 7 and 14 days with visibly greater live surface cellularity, layering, migration, and penetration. In part 2, bioluminescence imaging confirmed cell viability to day 22 after implantation. Biomechanical strength testing demonstrated a significant increase in ultimate failure load for reseeded groups compared with all other groups at week 2, whereas only reseeded grafts with hydrogel remained significantly stronger at weeks 4 and 8. Histologic examination demonstrated most increased tendinous cellular invasion and fibrocartilage repopulation at 8 weeks in the reseeded group with hydrogel. Masson trichrome staining demonstrated persistence of the scaffold structure at week 8 and blinded ImageJ analysis demonstrated significantly more type III collagen in the reseeded/hydrogel group at 2, 4, and 8 weeks. Conclusions: Decellularized lyophilized allogeneic tendon-bone interface scaffolds can be optimized by revitalization in platelet-rich plasma, reseeding with viable adipose-derived stem cells, and supplemented by an extracellular matrix tendon hydrogel at the time of implantation. When this is done, they display greater repair strength and biocompatibility.

Intratendinous Injection of Hydrogel for Reseeding Decellularized Human Flexor Tendons

Background: Decellularized cadaveric tendons are a potential source for reconstruction. Reseeding to enhance healing is ideal; however, cells placed on the tendon surface result in inadequate delivery. The authors used an injection technique to evaluate intratendinous cell delivery. Methods: Decellularized tendons were reseeded with adipose-derived stem cells in culture, and injected with fetal bovine serum or hydrogel. PKH26-stained cells in cross-section were quantified. To evaluate cell viability, the authors delivered luciferase-labeled cells and performed bioluminescent imaging. To evaluate synthetic ability, the authors performed immunohistochemistry of procollagen. Adipose-derived stem cells’ ability to attract tenocytes was assessed using transwell inserts. Cell-to-cell interaction was assessed by co-culturing, measuring proliferation and collagen production, and quantifying synergy. Finally, tensile strength was tested. Results: Both fetal bovine serum (p < 0.001) and hydrogel (p < 0.001) injection led to more cells inside the tendon compared with culturing. Hydrogel injection initially demonstrated greater bioluminescence than culturing (p < 0.005) and fetal bovine serum injection (p < 0.05). Injection groups demonstrated intratendinous procollagen staining correlating with the cells’ location. Co-culture led to greater tenocyte migration (p < 0.05). Interaction index of proliferation and collagen production assays were greater than 1 for all co-culture ratios, demonstrating synergistic proliferation and collagen production compared with controls (p < 0.05). There were no differences in tensile strength. Conclusions: Hydrogel injection demonstrated the greatest intratendinous seeding efficiency and consistency, without compromising tensile strength. Intratendinous cells demonstrated synthetic capabilities and can potentially attract tenocytes inside the tendon, where synergy would promote intrinsic tendon healing. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

An Inexpensive Bismuth-Petrolatum Dressing for Treatment of Burns.

Background: Xeroform remains the current standard for treating superficial partial-thickness burns but can be prohibitively expensive in developing countries with prevalent burn injuries. This study (1) describes the production of an alternative low-cost dressing and (2) compares the alternative dressing and Xeroform using the metrics of cost-effectiveness, antimicrobial activity, and biocompatibility in vitro, and wound healing in vivo. Methods: To produce the alternative dressing, 3% bismuth tribromophenate powder was combined with petroleum jelly by hand and applied to Kerlix gauze. To assess cost-effectiveness, the unit costs of Xeroform and components of the alternative dressing were compared. To assess antimicrobial properties, the dressings were placed on agar plated with Escherichia coli and the Kirby-Bauer assay performed. To assess biocompatibility, the dressings were incubated with human dermal fibroblasts and cells stained with methylene blue. To assess in vivo wound healing, dressings were applied to excisional wounds on rats and the rate of re-epithelialization calculated. Results: The alternative dressing costs 34% of the least expensive brand of Xeroform. Antimicrobial assays showed that both dressings had similar bacteriostatic effects. Biocompatibility assays showed that there was no statistical difference (P < 0.05) in the cytotoxicity of Xeroform, alternative dressing, and Kerlix gauze. Finally, the in vivo healing model showed no statistical difference (P < 0.05) in mean re-epithelialization time between Xeroform (13.0 ± 1.6 days) and alternative dressing (13.5 ± 1.0 days). Conclusions: Xeroform is biocompatible, reduces infection, and enhances healing of burn wounds by preventing desiccation and mechanical trauma. Handmade petrolatum gauze may be a low-cost replacement for Xeroform. Future studies will focus on clinical trials in burn units.

Tendon Regeneration with Tendon Hydrogel-Based Cell Delivery: A Comparison of Fibroblasts and Adipose-Derived Stem Cells

Background: Tendon hydrogel is a promising biomaterial for improving repair strength after tendon injury. This study compares the capacity of fibroblasts and adipose-derived stem cells to proliferate, survive, and acquire tenogenic properties when seeded into tendon hydrogel in vitro and in vivo. Methods: The effect of cell density on hydrogel contraction was measured macroscopically. To assess tenogenic properties, RNA was isolated from cells seeded in vitro in hydrogel, and tenocyte markers were quantified. To assess in vitro proliferation and survival, MTS and live-dead assays were performed. Finally, to assess the in vivo survival of cells in hydrogel, subcutaneous injections were performed on rats and in vivo imaging was performed. Results: At 0.5 million cells/ml, both the fibroblasts and adipose-derived stem cells induced minimal hydrogel contraction compared with higher cellular concentrations. Fibroblasts and adipose-derived stem cells seeded at 0.5 million cells/ml in tendon hydrogel up-regulated several tenocyte markers after 1 week. On MTS assay, fibroblasts and adipose-derived stem cells proliferated in hydrogel at similar rates. On live-dead assay, fibroblasts survived longer than adipose-derived stem cells. With use of the in vivo imaging system and histologic evaluation, fibroblasts survived longer than adipose-derived stem cells in hydrogel in vivo. Conclusions: Tendon healing is mediated by the proliferation, survival, and tenogenic differentiation of cells at the site of injury. Tendon hydrogel delivering dermal fibroblasts may improve and stimulate this process compared with adipose-derived stem cells. Future studies will be needed to evaluate the effects of this hydrogel-based cell delivery on chronic tendon injuries.

Overuse of Air Ambulance Services at a Regional Burn Center

Air ambulances rapidly transport burn patients to regional centers, expediting treatment. However, limited guidelines on transport introduce the risk for inappropriate triage and overuse. Given the additional costs of air vs ground transport, evaluation of transportation use is prudent. A retrospective review of all burn patients transported by helicopter to a single burn center from May 2013 to January 2016 was performed. Data gathered included patient demographics, transfer origin, burn characteristics, and inpatient hospital stay. The primary outcome was appropriate triage based on literature-derived severity criteria. Secondary outcomes included independent predictors of emergent treatments and the cost of overuse. Sixty-eight patients were examined, of which 66% met air ambulance criteria. Inappropriately triaged patients sustained smaller burns (% TBSA 4.8 vs 25.3, P < .001), had fewer flame burns (48 vs 82%, P = .007), had decreased lengths of stay (mean days 8.2 vs 21.2, P = .002), underwent fewer inpatient surgeries (mean 0.69 vs 2.57, P = .006), received no emergent procedures (0 vs 56%, P < .001), and suffered no deaths (0 vs 9%, P < .001). Independent predictors of emergent procedures included transport for airway concern (odds ratio = 45.29, confidence interval = 2.49-825.21, P = .010) and % TBSA (odds ratio = 1.13, confidence interval = 1.02-1.27, P = .019). If the 23 inappropriately triaged patients had been transported by ground, a cost savings of

Syndactyly: Apert Syndrome

106,370 could have been realized using 2016 California Medicare reimbursements (per-patient savings of

The Effects of Music on Microsurgical Technique and Performance A Motion Analysis Study

4624). While appropriate in most circumstances, the cost of air ambulances should be weighed in light of their utility, as a significant proportion of patients did not benefit from air transport.