Citations

Soft tissue sarcomas of the foot and ankle are common. Currently, there exist limited data on prognostic variables. The aim of this study was to review our institution’s experience with soft tissue sarcomas of the foot and ankle to identify factors affecting outcomes and survivorship. We reviewed the records of 62 foot and ankle soft tissue sarcomas treated with definitive surgery at our institution between 1992 and 2013. The cohort consisted of 35 males and 27 females with a mean age at diagnosis of 45 years and a mean follow-up of 7 years. The most common tumor subtype was synovial sarcoma (n = 16). The overall limb salvage rate was 53%. Local recurrence was observed in 9 patients and distant metastases in 15 patients. Tumor size ≥3 cm in maximal dimension was the greatest risk factor in mortality. Posttreatment complications occurred in 15 patients. Local recurrence and development of distant disease was relatively common following wide excision of a soft tissue sarcoma of the foot and ankle. Tumors that were ≥3 cm in maximal dimension were associated with a worse overall survival and patients with neoadjuvant radiation were at increased risk of complications. Levels of Evidence: Level IV: Retrospective Case Series

Objectives/HypothesisRadiation plays a prominent role in advanced stage head and neck tumors. Often, the radiated area includes adjacent nonmalignant mesenchymal tissue, which contains a mixture of cells that has been shown to accelerate wound healing. The purpose of this study is to determine the long‐term effect of radiation on the expansion potential of adipose‐derived stromal/stem cell (ADSC) tissue and on the ability of resident stem cells in this fraction to undergo phenotypic differentiation.Study Design/Methods: After institutional review board approval, 12 patients with a history of head and neck radiation and pending surgery were enrolled. Adipose tissue was collected from irradiated tissue (XRT) and nonirradiated tissue (NRT) sites. Mesenchymal stem cells were isolated from these populations, with subsequent assessment of cellular kinetics and differentiation potential between harvest sites.ResultsAdipose‐derived stromal/stem cells could not be isolated from XRT in six patients due to lack of in vitro cell proliferation. For the remaining six patients, overall cumulative population‐doubling time was longer for XRT relative to NRT (29.3 vs. 11.5 days; P = 0.02). However, no significant differences were observed in cell generation time or viability. When XRT and NRT ADSC fractions were grown to standardized concentrations and incubated under conditions that induce phenotypic differentiation of resident stem cells, no significant changes in chondrogenic, adipogenic, or osteogenic differentiation were observed.ConclusionThese preliminary observations suggest that irradiated ADSCs close to the surgical site undergo long‐term changes in proliferative capacity. The potential for phenotypic differentiation is retained, however, in ADSCs that survive the irradiation process.Level of Evidence2b.

For inherited cardiomyopathies, abnormal sensitivity to intracellular calcium (Ca2+), incurred from genetic mutations, initiates subsequent molecular events leading to pathological remodeling. Here, we characterized the effect of β‐adrenergic stress in familial dilated cardiomyopathy (DCM) using human‐induced pluripotent stem cell (hiPSC)‐derived cardiomyocytes (CMs) from a patient with RBM20 DCM. Our findings suggest that β‐adrenergic stimulation accelerated defective Ca2+ homeostasis, apoptotic changes, and sarcomeric disarray in familial DCM hiPSC‐CMs. Furthermore, pharmacological modulation of abnormal Ca2+ handling by pretreatment with β‐blocker, carvedilol, or Ca2+‐channel blocker, verapamil, significantly decreased the area under curve, reduced percentage of disorganized cells, and decreased terminal deoxynucleotidyl transferase‐mediated deoxyuridine triphosphate nick‐end labeling (TUNEL)‐positive apoptotic loci in familial DCM hiPSC‐CMs after β‐adrenergic stimulation. These translational data provide patient‐based in vitro analysis of β‐adrenergic stress in RBM20‐deficient familial DCM hiPSC‐CMs and evaluation of therapeutic interventions to modify heart disease progression, which may be personalized, but more importantly generalized in the clinic.

Purpose In order to achieve an oncological margin during limb salvage surgery for tumours around the hip, part or the entire hip joint is frequently sacrificed. Hip arthroplasty restores a functional extremity and achieves limb salvage. Currently there is a paucity of data concerning the late complications, long-term survival, and the risks of re-revision following aseptic revision of a total hip arthroplasty (THA) performed following an oncological resection. Methods We identified 78 patients who underwent aseptic revision of a THA which was performed for an oncological process involving the hip from 1972 to 2006. All patients had a minimum 5 years of follow-up with a mean of 13 years. Outcomes were compared to 1,378 patients undergoing aseptic revision of a THA that was performed for a diagnosis of osteoarthritis. Results The mean 5-, 10-, 15-, and 20-year re-revision-free survival for an oncologic process of the hip was 100%, 85%, 69%, and 57%. Within this cohort, younger patients were at an increased risk of revision surgery. There was no difference in survivorship of the revision implant at any of the aforementioned time points between the oncologic and osteoarthritis cohorts. Patients with an oncologic diagnosis had a higher rate of dislocations, component wear, and loosening compared to the osteoarthritis group. Conclusion Late complications following revision surgery of THA performed for an oncologic resection are common. The results of this study provide information for counselling patients on implant survivorship and complications following aseptic revision THA after index surgery for an oncologic indication.

Background Cardiac resynchronization therapy using bi‐ventricular pacing is proven effective in the management of heart failure (HF) with a wide QRS ‐complex. In the absence of QRS prolongation, however, device‐based resynchronization is reported unsuitable. As an alternative, the present study tests a regenerative cell‐based approach in the setting of narrow QRS ‐complex HF. Methods and Results Progressive cardiac dyssynchrony was provoked in a chronic transgenic model of stress‐triggered dilated cardiomyopathy. In contrast to rampant end‐stage disease afflicting untreated cohorts, stem cell intervention early in disease, characterized by mechanical dyssynchrony and a narrow QRS ‐complex, aborted progressive dyssynchronous HF and prevented QRS widening. Stem cell‐treated hearts acquired coordinated ventricular contraction and relaxation supporting systolic and diastolic performance. Rescue of contractile dynamics was underpinned by a halted left ventricular dilatation, limited hypertrophy, and reduced fibrosis. Reverse remodeling reflected a restored cardiomyopathic proteome, enforced at systems level through correction of the pathological molecular landscape and nullified adverse cardiac outcomes. Cell therapy of a dyssynchrony‐prone cardiomyopathic cohort translated prospectively into improved exercise capacity and prolonged survivorship. Conclusions In narrow QRS HF, a regenerative approach demonstrated functional and structural benefit, introducing the prospect of device‐autonomous resynchronization therapy for refractory disease.

Stem cells harbor significant potential for regenerative medicine as well as basic and clinical translational research. Prior to harnessing their reparative nature for degenerative diseases, concerns regarding their genetic integrity and mutation acquisition need to be addressed. Here we review pluripotent and multipotent stem cell response to DNA damage including differences in DNA repair kinetics, specific repair pathways (homologous recombination vs. non-homologous end joining), and apoptotic sensitivity. We also describe DNA damage and repair strategies during reprogramming and discuss potential genotoxic agents that can reduce the inherent risk for teratoma formation and mutation accumulation. Ensuring genomic stability in stem cell lines is required to achieve the quality control standards for safe clinical application.

The advent of induced pluripotent stem cell (iPSC) technology creates new opportunities for transplant-based therapeutic strategies. The potential for clinical translation is currently hindered by the risk of dysregulated cell growth. Pluripotent stem cells reprogrammed by three-factor (Sox2, Klf, and Oct4) and four-factor (Sox2, Klf, Oct4, and c-Myc) strategies result in the capacity for teratogenic growth from residual pluripotent progeny upon in vivo transplantation. However, these pluripotent stem cells also have a stage-specific hypersensitivity to DNA-damaging agents that may allow separation of lineage-specific therapeutic subpopulation of cells. We aimed to demonstrate the selective effect of DNA topoisomerase II inhibitor, etoposide, in eliminating pluripotent cells in the early cardiac progenitor population thus decreasing the effect of teratoma formation. Immunodeficient murine hearts were infarcted and received implantation of a therapeutic dose of cardiac progenitors derived from partially differentiated iPSCs. Etoposide-treated cell implantation reduced mass formation in the intracardiac and extracardiac chest cavity compared with the same dose of iPSC-derived cardiac progenitors in the control untreated group. In vivo bioluminescence imaging confirmed the localization and engraftment of transplanted cells in the myocardium postinjection in both groups. Comparatively, the equivalent cell population without etoposide treatment demonstrated a greater incidence and size of teratoma formation. Hence, pretreatment with genotoxic etoposide significantly lowered the threat of teratogenicity by purging the contaminating pluripotent cells, establishing an adjunctive therapy to further harness the clinical value of iPSC-derived cardiac regeneration.