Citations

BACKGROUND Dermatofibrosarcoma protuberans (DFSP) is a soft tissue tumor with slow infiltrative growth and local recurrence if inadequately excised. OBJECTIVE To compare long-term outcomes after Mohs micrographic surgery (MMS) and wide local excision (WLE). MATERIALS AND METHODS Records of patients with DFSP surgically treated with WLE or MMS from January 1955 through March 2012 were retrospectively reviewed. RESULTS Mean follow-up for patients treated with MMS (n = 67) and WLE (n = 91) was 4.8 and 5.7 years, respectively. Twenty-eight patients (30.8%) with WLE had recurrence (mean, 4.4 years), whereas only 2 (3.0%) with MMS had recurrence (1.0 and 2.6 years). Recurrence-free survival rates at 1, 5, 10, and 15 years were significantly higher with MMS (p < .001). Mean preoperative lesion sizes were similar (5–6 cm) between the 2 groups, whereas mean (standard deviation) postoperative defect sizes were 10.7 (4.3) cm and 8.8 (5.5) cm for WLE and MMS, respectively (p = .004). Primary closure was used for 73% of MMS cases, whereas WLE more commonly used flaps, grafts, or other closures (52%). Two Mohs layers typically were required for margin control. CONCLUSION Surgical excision with meticulous histologic evaluation of all surgical margins is needed for DFSP treatment to achieve long-term high cure rates and low morbidity.

Objective/Hypothesis: Processed nerve allografts provide a promising alternative to nerve autografts with the advantages of a readily available unlimited supply, no donor site morbidity, and without the need for immunosuppression. The nerve allografts currently available for clinical use do not provide satisfactory results. The processing technique was optimized to reduce the allografts immunogenicity and cellular debris while maintaining the ultrastructural properties. The aim of this study was to evaluate the functional recovery after reconstruction of a long nerve gap using the optimized nerve allograft in a rabbit model. To study the influence of storage techniques on functional recovery, processed nerve allografts were either cold or frozen stored. The nerve allografts were challenged to the gold standard, the nerve autograft. Materials and Methods: Nerve allografts were decellularized using our optimized protocol and stored at either 4°C or −80°C. In 36 New Zealand White rabbits, a 3-cm peroneal nerve gap was repaired with either a cold or frozen stored processed nerve allograft or a nerve autograft (control). Nerve recovery was longitudinally evaluated with ultrasound measurements performed prior to surgery and at 10, 16, and 24 weeks follow-up. Functional motor recovery was determined 24 weeks postoperatively using electrophysiology (compound muscle action potentials [CMAP]), isometric tetanic force (ITF), wet muscle weight (MW), and histomorphometry. Results: The longitudinal ultrasound measurements showed that the cold stored nerve allograft provides faster and earlier regeneration than the frozen stored nerve allograft. At 24 weeks, the cold stored allograft showed equal results compared with the autograft based on ultrasound measurements. Ultrasound furthermore showed significantly impaired recovery in the frozen stored allograft group compared with both the cold stored allograft and autograft ( P < .05). The functional outcome measurements, MV and ITF, both showed that the cold stored allograft proved to have a similar result compared with the autograft ( P > .05 for both MW and ITF, respectively). The frozen stored allograft, however, had a significantly inferior result to the autograft ( P < .05 for both MW and ITF). The CMAP and histomorphometry results showed no significant differences between all 3 groups. Conclusions: Nerve reconstruction with the cold stored optimized nerve allograft results in successful recovery of a long motor nerve defect in a rabbit model, statistically equivalent to the gold standard nerve autograft. Freeze storage of the processed allograft impairs the functional outcome.

AbstractCulture conditions that induce hepatic spheroidal aggregates sustain liver cells with metabolism that mimics in vivo hepatocytes. Here we present an array of elastin‐like polypeptide conjugate coating materials (Aminated‐ELPs) that are biocompatible, have spheroid‐forming capacity, can be coated atop traditional culture surfaces, and maintain structural integrity while ensuring adherence of spheroids over long culture period. The Aminated‐ELPs were synthesized either by direct conjugation of ELP and various polyelectrolytes or by conjugating both ELP and various small electrolytes to the reactive polymer poly(2‐vinyl‐4,4‐dimethyl azlactone) (PVDMA). Spheroid morphology, cellular metabolic function, and liver‐specific gene expression over the long‐term, 20‐day culture period were assessed through optical microscopy, measurement of total protein content and albumin and urea production, and quantitative real‐time (qRT) PCR. We found that the amine content of the Aminated‐ELP coatings dictated the initial hepatocyte attachment, but not the subsequent hepatocyte spheroid formation and their continued attachment. A lower amine content was generally found to sustain higher albumin production by the spheroids. Out of the 19 Aminated‐ELP coatings tested, we found that the lysine‐containing substrates comprising ELP‐polylysine or ELP‐PVDMA‐butanediamine proved to consistently culture productive spheroidal hepatocytes. We suggest that the incorporation of lysine functional groups in Aminated‐ELP rendered more biocompatible surfaces, increasing spheroid attachment and leading to increased liver‐specific function. Taken together, the Aminated‐ELP array presented here has the potential to create in vitro hepatocyte culture models that mimic in vivo liver functionality and thus, lead to better understanding of liver pathophysiology and superior screening methods for drug efficacy and toxicity. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 377–388, 2017.

Key points We developed a method that allows for real‐time assessment of cellular metabolism in isolated, intact long skeletal muscle fibre bundles from adult mice. This method can be used to study changes in mitochondrial function and fuel utilisation in live skeletal muscle fibre bundles. Our method enables flexibility in experimental design and high‐throughput assessment of mitochondrial parameters in isolated skeletal muscle fibre bundles. Extensor digitorum longus (EDL) fibre bundles obtained from chronic high‐fat diet fed mice had lower basal oxygen consumption under FCCP‐induced maximal respiration, when compared to control chow‐fed mice. EDL fibre bundles obtained from chronic high‐fat diet fed mice had enhanced mitochondrial oxidation capacity under FCCP‐induced maximal respiration, when compared to control chow‐fed mice. AbstractMetabolic dysfunction in skeletal muscle contributes to the aetiology and development of muscle diseases and metabolic diseases. As such, assessment of skeletal muscle cellular bioenergetics provides a powerful means to understand the role of skeletal muscle metabolism in disease and to identify possible therapeutic targets. Here, we developed a method that allows for the real‐time assessment of cellular respiration in intact skeletal muscle fibre bundles obtained from the extensor digitorum longus (EDL) muscle of adult mice. Using this method, we assessed the contribution of ATP turnover and proton leak to basal mitochondrial oxygen consumption rate (OCR). Our data demonstrate that the mitochondria in EDL fibres are loosely coupled. Moreover, in the presence of carbonyl cyanide‐p‐trifluoromethoxyphenylhydrazone (FCCP), we show that palmitate exposure induced comparable peak OCR and higher total OCR in EDL fibre bundles when compared to pyruvate exposure, suggesting that fatty acids might be a more sustainable fuel source for skeletal muscle when mitochondria are driven to maximal respiration. Application of this method to EDL fibre bundles obtained from chronic high‐fat diet fed mice revealed lower basal OCR and enhanced mitochondrial oxidation capacity in the presence of FCCP when compared to the chow‐diet fed control mice. By using a 96‐well microplate format, our method provides a flexible and efficient platform to investigate mitochondrial parameters of intact skeletal muscle fibres obtained from adult mice.

Mutagenesis screening is a powerful forward genetic approach that has been successfully applied in lower-model organisms to discover genetic factors for biological processes. This phenotype-based approach has yet to be established in vertebrates for probing major human diseases, largely because of the complexity of colony management. Herein, we report a rapid strategy for identifying genetic modifiers of cardiomyopathy (CM). Based on the application of doxorubicin stress to zebrafish insertional cardiac (ZIC) mutants, we identified 4 candidate CM-modifying genes, of which 3 have been linked previously to CM. The long isoform of DnaJ (Hsp40) homolog, subfamily B, member 6b ( dnajb6b(L) ) was identified as a CM susceptibility gene, supported by identification of rare variants in its human ortholog DNAJB6 from CM patients. Mechanistic studies indicated that the deleterious, loss-of-function modifying effects of dnajb6b(L) can be ameliorated by inhibition of ER stress. In contrast, overexpression of dnajb6(L) exerts cardioprotective effects on both fish and mouse CM models. Together, our findings establish a mutagenesis screening strategy that is scalable for systematic identification of genetic modifiers of CM, feasible to suggest therapeutic targets, and expandable to other major human diseases.

Background: Multiple enchodromatosis of bone, termed Ollier’s disease, or Maffucci syndrome when associated with hemangiomas, is a rare disease that can affect the pediatric hand. This condition often causes a finger mass, deformity, pain and possible pathologic fractures, and has been associated with malignant transformation to chondrosarcoma. The aim of our study is to describe the long-term sequela of multiple enchondromatosis of the hand in the pediatric population, specifically the rates of malignant transformation, tumor recurrence, rates of pathologic fracture, and phalangeal growth arrest. Methods: We examined 15 pediatric patients who were treated in our institute with a total of 127 phalanges and metacarpals lesions. Only patients with follow-up of at least 4 years were included. We retrospectively reviewed patients’ chart and hand radiograph for symptoms including pathologic fractures, indications for surgery, and postoperative complications including tumor recurrence, and malignant transformation. We assessed phalangeal growth arrest with radiographs and normalized phalangeal growth charts. Results: Mean age of diagnosis was 5.8 years and mean follow-up time was 15.4 years. Pathologic fractures were common at 46% of pediatric patients, but ceased to occur once reaching adulthood. Outcomes of pathologic fractures were excellent, regardless of treatment. Malignant transformation occurred in 1 patient and did not occur during childhood. A total of 80% of patients and 29% of lesions underwent surgical treatment of curettage and bone graft for the lesion, yet recurrence was common and affected 33% of treated patients. Phalangeal growth arrest was the most common long-term sequela and affected 11% of phalanxes and metacarpals. This sequela was significantly more prevalent in patients who had surgical excision of the tumor. Conclusions: Our findings reassure that malignant transformation of enchodromatosis of the hand is unlikely in the pediatric population. Pathologic fracture is common, but has excellent outcomes. When considering surgery, parents should be counseled about the possibility of phalangeal growth arrest and recurrence of the lesion. Type of Study/Level of Evidence: Level IV—therapeutic.