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We present a rare iatrogenic cholesteatoma of the neck in a ten year old male four years after tympanomastoidectomy, an entity that to our knowledge has not been published in the literature for over 30 years. Furthermore, we discuss the diagnostic uncertainty of typical magnetic resonance imaging protocols for pediatric neck lesions and the improved diagnostic specificity of diffusion weighted magnetic resonance imaging. En bloc surgical extirpation was performed. Laryngoscope, 131:E882-E884, 2021.

Biphasic calcium phosphate scaffolds formed via three dimensional (3D) printing technology to exhibit porosity and chemical resorbability to promote osseointegration often lack the strength and toughness required to withstand loading in bone tissue engineering applications. Herein, sintering and CaP:poly(caprolactone) (PCL) composite formation were explored to improve 3D printed scaffold strength and toughness. Hydroxyapatite and α-tricalcium phosphate (α-TCP) biphasic calcium powders were printed using phosphoric acid binder, which generated monetite and hydroxyapatite scaffolds. Upon sintering, evolution of β-TCP was observed along with an increase in flexural strength and modulus but no effect on fracture toughness was observed. Furthermore, scaffold porosity increased with sintering. Additionally, two techniques of PCL composite formation were employed: postprint precipitation and 3D print codeposition to further augment scaffold mechanical properties. While both techniques significantly improved flexural strength, flexural modulus, and fracture toughness under most conditions explored, precipitation yielded more substantial increases in these properties, which is attributed to better continuity of the PCL phase. However, precipitation also compromised surface porosity due to PCL passivation of the calcium phosphate surface, which may subsequently hinder scaffold integration and bone regeneration. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 663-672, 2018.

Purpose of review This article highlights important trends in speech outcomes following orthognathic surgery in the cleft lip and palate populations. The geometric changes in the velopharyngeal port caused by maxillary advancement by standard means and distraction are only one consideration in predicting speech outcomes. Myriad and variable preoperative risk factors, both anatomic and functional, have been identified in the literature because of weaknesses in experimental design and small patient populations. Therefore, elucidating risk factors for postoperative velopharyngeal dysfunction remains a challenge in our field. Recent findings Recent pharyngeal morphologic studies using computed tomography demonstrate volumetric discrepancies in the unilateral and bilateral cleft lip and palate populations before and after orthognathic surgery, suggesting differing requirements of velar adaptation among these two populations. Perceptual and instrumental speech evaluation studies and cephalometric correlates revisit 'borderline' velopharyngeal insufficiency and isolate preoperative velar length as a risk factor for velopharyngeal dysfunction following orthognathic surgery. Summary Research design heterogeneity, small patient populations, and inherent risk of bias of retrospective reviews obscure velopharyngeal dysfunction risk factor identification prior to orthognathic surgery. However, recent reports on the volumetric changes in the pharyngeal airway and preoperative 'borderline' velopharyngeal insufficiency and velar length offer improved predictive value in anticipating postoperative velopharyngeal dysfunction.

Longitudinal blood flow during murine bone graft healing was monitored non-invasively using diffuse correlation tomography. The system utilized spatially dense data from a scanning set-up, non-linear reconstruction, and micro-CT anatomical information. Weekly in vivo measurements were performed. Blood flow changes in autografts, which heal successfully, were localized to graft regions and consistent across mice. Poor healing allografts showed heterogeneous blood flow elevation and high inter-subject variabilities. Allografts with tissue-engineered periosteum showed responses intermediate to both autografts and allografts, consistent with healing observed. These findings suggest that spatiotemporal blood flow changes can be utilized to differentiate the degree of bone graft healing.

We developed spatially dense diffuse correlation tomography instrument and reconstruction algorithm to monitor 3D blood flow changes in murine femoral grafts. Our preliminary results show spatially resolved blood flow changes in a mouse allograft.

Although cellular transplantation has been shown to promote improvements in cardiac function following injury, poor cell survival following transplantation continues to limit the efficacy of this therapy. We have previously observed that transplantation of muscle-derived stem cells (MDSCs) improves cardiac function in an acute murine model of myocardial infarction to a greater extent than myoblasts. This improved regenerative capacity of MDSCs is linked to their increased level of antioxidants such as glutathione (GSH) and superoxide dismutase. In the current study, we demonstrated the pivotal role of antioxidant levels on MDSCs survival and cardiac functional recovery by either reducing the antioxidant levels with diethyl maleate or increasing antioxidant levels with N-acetylcysteine (NAC). Both the anti- and pro-oxidant treatments dramatically influenced the survival of the MDSCs in vitro. When NAC-treated MDSCs were transplanted into infarcted myocardium, we observed significantly improved cardiac function, decreased scar tissue formation, and increased numbers of CD31(+) endothelial cell structures, compared to the injection of untreated and diethyl maleate-treated cells. These results indicate that elevating the levels of antioxidants in MDSCs with NAC can significantly influence their tissue regeneration capacity.

Stem cells are classically defined by their multipotent, long-term proliferation, and self-renewal capabilities. Here, we show that increased antioxidant capacity represents an additional functional characteristic of muscle-derived stem cells (MDSCs). Seeking to understand the superior regenerative capacity of MDSCs compared with myoblasts in cardiac and skeletal muscle transplantation, our group hypothesized that survival of the oxidative and inflammatory stress inherent to transplantation may play an important role. Evidence of increased enzymatic and nonenzymatic antioxidant capacity of MDSCs were observed in terms of higher levels of superoxide dismutase and glutathione, which appears to confer a differentiation and survival advantage. Further when glutathione levels of the MDSCs are lowered to that of myoblasts, the transplantation advantage of MDSCs over myoblasts is lost when transplanted into both skeletal and cardiac muscles. These findings elucidate an important cause for the superior regenerative capacity of MDSCs, and provide functional evidence for the emerging role of antioxidant capacity as a critical property for MDSC survival post-transplantation.

Vascular infiltration and associated alterations in microvascular blood flow are critical for complete bone graft healing. Therefore, real-time, longitudinal measurement of blood flow has the potential to successfully predict graft healing outcomes. Herein, we non-invasively measure longitudinal blood flow changes in bone autografts and allografts using diffuse correlation spectroscopy in a murine femoral segmental defect model. Blood flow was measured at several positions proximal and distal to the graft site before implantation and every week post-implantation for a total of 9 weeks (autograft n = 7 and allograft n = 10). Measurements of the ipsilateral leg with the graft were compared with those of the intact contralateral control leg. Both autografts and allografts exhibited an initial increase in blood flow followed by a gradual return to baseline levels. Blood flow elevation lasted up to 2 weeks in autografts, but this duration varied from 2 to 6 weeks in allografts depending on the spatial location of the measurement. Intact contralateral control leg blood flow remained at baseline levels throughout the 9 weeks in the autograft group; however, in the allograft group, blood flow followed a similar trend to the graft leg. Blood flow difference between the graft and contralateral legs (ΔrBF), a parameter defined to estimate graft-specific changes, was elevated at 1–2 weeks for the autograft group, and at 2–4 weeks for the allograft group at the proximal and the central locations. However, distal to the graft, the allograft group exhibited significantly greater ΔrBF than the autograft group at 3 weeks post-surgery (p < 0.05). These spatial and temporal differences in blood flow supports established trends of delayed healing in allografts versus autografts.

Background Anaplastic carcinoma arising within a mucinous ovarian neoplasm is rare, with only about 30 reported cases. Reported cases have given a broad age range, ranging from 17 to 72 years of age, but occurrence in adolescents is exceptional, with only a few cases reported. Case We report a case of anaplastic carcinoma arising in a mucinous cystadenocarcinoma in a 17-year-old female who presented with severe abdominal pain, an unusual symptom for an ovarian malignancy in the postmenopausal patient, but not in the adolescent. The patient had widespread metastases at the time of presentation, consistent with the aggressive behavior of this neoplasm. Conclusions This case illustrates that, although rare, epithelial ovarian malignancy is in the differential diagnosis of abdominal pain in an adolescent.

Background Despite the initial promise of myoblast transfer therapy to restore dystrophin in Duchenne muscular dystrophy patients, clinical efficacy has been limited, primarily by poor cell survival post-transplantation. Murine muscle derived stem cells (MDSCs) isolated from slowly adhering cells (SACs) via the preplate technique, induce greater muscle regeneration than murine myoblasts, primarily due to improved post-transplantation survival, which is conferred by their increased stress resistance capacity. Aldehyde dehydrogenase (ALDH) represents a family of enzymes with important morphogenic as well as oxidative damage mitigating roles and has been found to be a marker of stem cells in both normal and malignant tissue. In this study, we hypothesized that elevated ALDH levels could identify murine and human muscle derived cell (hMDC) progenitors, endowed with enhanced stress resistance and muscle regeneration capacity. Methodology/Principal Findings Skeletal muscle progenitors were isolated from murine and human skeletal muscle by a modified preplate technique and unfractionated enzymatic digestion, respectively. ALDHhi subpopulations isolated by fluorescence activate cell sorting demonstrated increased proliferation and myogenic differentiation capacities compared to their ALDHlo counterparts when cultivated in oxidative and inflammatory stress media conditions. This behavior correlated with increased intracellular levels of reduced glutathione and superoxide dismutase. ALDHhi murine myoblasts were observed to exhibit an increased muscle regenerative potential compared to ALDHlo myoblasts, undergo multipotent differentiation (osteogenic and chondrogenic), and were found predominately in the SAC fraction, characteristics that are also observed in murine MDSCs. Likewise, human ALDHhi hMDCs demonstrated superior muscle regenerative capacity compared to ALDHlo hMDCs. Conclusions The methodology of isolating myogenic cells on the basis of elevated ALDH activity yielded cells with increased stress resistance, a behavior that conferred increased regenerative capacity of dystrophic murine skeletal muscle. This result demonstrates the critical role of stress resistance in myogenic cell therapy as well as confirms the role of ALDH as a marker for rapid isolation of murine and human myogenic progenitors for cell therapy.