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Atherosclerosis is a primary precursor of cardiovascular disease (CVD), the leading cause of death worldwide. While proprotein convertase subtilisin/kexin 9 (PCSK9) contributes to CVD by degrading low-density lipoprotein receptors (LDLR) and altering lipid metabolism, PCSK9 also influences vascular inflammation, further promoting atherosclerosis. Here, we utilized a vascular microphysiological system to test the effect of PCSK9 activation or repression on the initiation of atherosclerosis and to screen the efficacy of a small molecule PCSK9 inhibitor. We have generated PCSK9 over-expressed (P+) or repressed (P-) human induced pluripotent stem cells (iPSCs) and further differentiated them to smooth muscle cells (viSMCs) or endothelial cells (viECs). Tissue-engineered blood vessels (TEBVs) made from P+ viSMCs and viECs resulted in increased monocyte adhesion compared to the wild type (WT) or P- equivalents when treated with enzyme-modified LDL (eLDL) and TNF-α. We also found significant viEC dysfunction, such as increased secretion of VCAM-1, TNF-α, and IL-6, in P+ viECs treated with eLDL and TNF-α. A small molecule compound, NYX-1492, that was originally designed to block PCSK9 binding with the LDLR was tested in TEBVs to determine its effect on lowering PCSK9-induced inflammation. The compound reduced monocyte adhesion in P+ TEBVs with evidence of lowering secretion of VCAM-1 and TNF-α. These results suggest that PCSK9 inhibition may decrease vascular inflammation in addition to lowering plasma LDL levels, enhancing its anti-atherosclerotic effects, particularly in patients with elevated chronic inflammation., Competing Interests: Yes, A.K.S. and B.J.E. are employees of Nyrada, Inc. and are listed as inventors on a patent that discloses NYX-1492 and related compounds. B.J.E. has share/stock options in Nyrada Inc. J.B.K. and C.A.G. have field patent applications related to technologies for genome engineering and cell reprogramming. C.A.G. is a co-founder of Tune Therapeutics and Locus Biosciences and is an advisor to Tune Therapeutics, Sarepta Therapeutics, Levo Therapeutics, and Iveric Bio., (© 2023 Author(s).)

Objectives  Given the limitations in the available literature, the precise indications, techniques, and outcomes of anterior skull base free flap reconstruction remain uncertain. The objective of this study was to perform a systematic review of published literature and evaluate indications, methods, and complications for anterior skull base free flap reconstruction. Methods  A systematic review of the literature was performed using a set of search criteria to identify patients who underwent free flap reconstruction of the anterior skull base. Articles were reviewed for inclusion based on relevance, with the primary outcome being surgical complications. Results  After a comprehensive search, 406 articles were obtained and 16 articles were ultimately found to be relevant to this review-79 patients undergoing free flap reconstruction were identified. Overall complication rates were 17.7% (95% confidence interval [CI]: 16.6-33.1%) for major complications and 19.0% (95% CI: 17.8-35.5%) for minor complications. Conclusion  Microvascular reconstruction of the anterior skull base is feasible with high reliability reported in the literature., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)

Objective: To evaluate the prevalence, surgical management, and audiologic impact of pulsatile tinnitus caused by sigmoid sinus dehiscence., Study Design and Setting: Retrospective chart review at a tertiary care hospital., Patients: Adults with unilateral pulsatile tinnitus attributable to sigmoid sinus dehiscence who underwent resurfacing between January 2010 and January 2020., Interventions: Transmastoid sigmoid resurfacing., Main Outcome Measures: Resolution of pulsatile tinnitus; audiologic outcomes; complications; tinnitus etiologies., Results: Nineteen patients (89.4% women) had surgery for suspected sigmoid sinus dehiscence. The mean dehiscence size was 6.1 mm (range, 1-10.7 mm). Eight patients had concurrent sigmoid sinus diverticulum and one patient also had jugular bulb dehiscence. Only two patients (10.5%) had the defect identified by radiology. Low-frequency pure-tone average, measured at frequencies of 250 and 500 Hz, showed a significant median improvement of 8.8 dB following resurfacing (18.8 dB versus 10.0 dB, p = 0.02). The majority of patients had complete resolution of pulsatile tinnitus (16/19, 84.2%). Of those without complete resolution, two patients had partial response and one patient had no improvement. There were no significant complications. Of 41 consecutively tracked patients with a pulsatile tinnitus chief complaint, sigmoid pathology represented 32% of cases., Conclusions: Sigmoid sinus dehiscence represents a common vascular cause of pulsatile tinnitus that, if properly assessed, may be amenable to surgical intervention. Sigmoid sinus resurfacing is safe, does not require decompression, and may improve low-frequency hearing. Radiographic findings of dehiscence are often overlooked without a high index of clinical suspicion. Its relationship with transverse sinus pathology and idiopathic intracranial hypertension remain unclear.

Delivery of therapeutic transgenes with adeno-associated viral (AAV) vectors for treatment of myopathies has yielded encouraging results in animal models and early clinical studies. Although certain AAV serotypes efficiently target muscle fibers, transduction of the muscle stem cells, also known as satellite cells, is less studied. Here, we used a Pax7nGFP;Ai9 dual reporter mouse to quantify AAV transduction events in satellite cells. We assessed a panel of AAV serotypes for satellite cell tropism in the mdx mouse model of Duchenne muscular dystrophy and observed the highest satellite cell labeling with AAV9 following local or systemic administration. Subsequently, we used AAV9 to interrogate CRISPR/Cas9-mediated gene editing of satellite cells in the Pax7nGFP;mdx mouse. We quantified the level of gene editing using a Tn5 transposon-based method for unbiased sequencing of editing outcomes at the Dmd locus. We also found that muscle-specific promoters can drive transgene expression and gene editing in satellite cells. Lastly, to demonstrate the functionality of satellite cells edited at the Dmd locus by CRISPR in vivo , we performed a transplantation experiment and observed increased dystrophin-positive fibers in the recipient mouse. Collectively, our results confirm that satellite cells are transduced by AAV and can undergo gene editing to restore the dystrophin reading frame in the mdx mouse., (© 2020 The Author(s).)

Engineered CRISPR/Cas9-based transcriptional activators can potently and specifically activate endogenous fate-determining genes to direct differentiation of pluripotent stem cells. Here, we demonstrate that endogenous activation of the PAX7 transcription factor results in stable epigenetic remodeling and differentiates human pluripotent stem cells into skeletal myogenic progenitor cells. Compared with exogenous overexpression of PAX7 cDNA, we find that endogenous activation results in the generation of more proliferative myogenic progenitors that can maintain PAX7 expression over multiple passages in serum-free conditions while preserving the capacity for terminal myogenic differentiation. Transplantation of human myogenic progenitors derived from endogenous activation of PAX7 into immunodeficient mice resulted in a greater number of human dystrophin + myofibers compared with exogenous PAX7 overexpression. RNA-sequencing analysis also revealed transcriptome-wide differences between myogenic progenitors generated via CRISPR-based endogenous activation of PAX7 and exogenous PAX7 cDNA overexpression. These studies demonstrate the utility of CRISPR/Cas9-based transcriptional activators for controlling cell-fate decisions., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: Ablations of locally advanced or recurrent head and neck cancer commonly result in large composite orofacial defects. Chimeric flaps represent a unique surgical option for these defects, as they provide diverse tissue types from a single donor site. The purpose of the study was to consolidate the literature on chimeric flaps with regard to postoperative complication rates to help inform surgical decision making., Data Sources: The librarian created search strategies with a combination of keywords and controlled vocabulary in Ovid Medline (1946), Embase (1947), Scopus (1823), Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, and Clinicaltrails.gov (1997)., Review Methods: Candidate articles were independently reviewed by 2 authors familiar with the subject material, and inclusion/exclusion criteria were uniformly applied for article selection. Articles were considered eligible if they included patients who received a single chimeric flap for reconstruction of head and neck defects and if they provided data on complication rates., Results: A total of 521 chimeric flaps were included in the study. The major complication rate was 22.6%, while the minor complication rate was 14.0%. There were 7 flap deaths noted in the series. Median operative time and harvest time were 15.0 and 2.5 hours, respectively., Conclusion: Chimeric flaps represent a viable option for reconstruction of complex head and neck defects and have complication rates similar to those of double free flaps and single free flaps with locoregional flap while only modestly increasing total operative time.

In the current value-based health-care environment, 30-day unplanned hospital readmissions have been identified as a quality measure and an opportunity to help reduce health-care costs. The LACE Index Scoring Tool for Risk Assessment of Death and Readmission utilizes length of stay, acuity of admission, comorbidities, and emergency department visits to stratify patients into high and low risk of readmission. A retrospective chart review of 161 patients who underwent a tracheotomy or laryngectomy for head and neck indications at a tertiary care academic center demonstrated that the readmitted patient cohort was not statistically or clinically different from the nonreadmitted cohort when comparing LACE scores ( P = .789), length of hospital stay ( P = .237), discharge disposition ( P = .569), or insurance status ( P = .85). Addressing the problem of unplanned 30-day readmissions will likely require enhanced patient education, improved coordination of care, and further research.

Objectives (1) To describe the presentation, management, and outcomes associated with pediatric esophageal food impaction (EFI) at a single tertiary care institution. (2) To identify the key clinical features of pediatric EFI that are associated with a diagnosis of eosinophilic esophagitis (EoE). Study Design Case series with chart review. Setting Tertiary care children's hospital. Subjects and Methods Thirty-five children <18 years of age presenting with EFI between November 1, 2006, and October 31, 2013, were included. Presenting symptoms, medical history, biopsy results, endoscopic findings, and underlying etiology were examined. Fisher exact test, t tests, and logistic regression were used to compare between patients with and without EoE. Results Thirty-five patients had isolated EFI and were included in the study. EoE accounted for 74% (n = 26) of pediatric EFI, with the remaining cases being attributed to neurologic impairment (n = 5, 15%), prior surgeries (n = 1, 3%), reflux esophagitis (n = 1, 3%), or unknown etiologies (n = 2, 6%). EFI was the initial manifestation of EoE in 81% (n = 21) of patients. The most common presenting symptoms were dysphagia (n = 34), choking (n = 26), and vomiting (n = 23). Linear furrowing was the only endoscopic finding that was significantly associated with EoE ( P < .001). Conclusion Most esophageal food impactions in the pediatric population are associated with an underlying diagnosis of EoE and are often the initial manifestation of the disease. EoE must be considered in all pediatric patients with EFI; esophageal biopsies should be strongly considered in these patients at the time of endoscopic management of the EFI.

Cartilage-derived matrix (CDM) has emerged as a promising scaffold material for tissue engineering of cartilage and bone due to its native chondroinductive capacity and its ability to support endochondral ossification. Because it consists of native tissue, CDM can undergo cellular remodeling, which can promote integration with host tissue and enables it to be degraded and replaced by neotissue over time. However, enzymatic degradation of decellularized tissues can occur unpredictably and may not allow sufficient time for mechanically competent tissue to form, especially in the harsh inflammatory environment of a diseased joint. The goal of the current study was to engineer cartilage and bone constructs with the ability to inhibit aberrant inflammatory processes caused by the cytokine interleukin-1 (IL-1), through scaffold-mediated delivery of lentiviral particles containing a doxycycline-inducible IL-1 receptor antagonist (IL-1Ra) transgene on anatomically-shaped CDM constructs. Additionally, scaffold-mediated lentiviral gene delivery was used to facilitate spatial organization of simultaneous chondrogenic and osteogenic differentiation via site-specific transduction of a single mesenchymal stem cell (MSC) population to overexpress either chondrogenic, transforming growth factor-beta 3 (TGF-β3), or osteogenic, bone morphogenetic protein-2 (BMP-2), transgenes. Controlled induction of IL-1Ra expression protected CDM hemispheres from inflammation-mediated degradation, and supported robust bone and cartilage tissue formation even in the presence of IL-1. In the absence of inflammatory stimuli, controlled cellular remodeling was exploited as a mechanism for fusing concentric CDM hemispheres overexpressing BMP-2 and TGF-β3 into a single bi-layered osteochondral construct. Our findings demonstrate that site-specific delivery of inducible and tunable transgenes confers spatial and temporal control over both CDM scaffold remodeling and neotissue composition. Furthermore, these constructs provide a microphysiological in vitro joint organoid model with site-specific, tunable, and inducible protein delivery systems for examining the spatiotemporal response to pro-anabolic and/or inflammatory signaling across the osteochondral interface., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Children with a button battery impaction present with nonspecific symptoms that may account for a delay in medical care. We conducted a retrospective study of the clinical presentation, management, and complications associated with button battery ingestion in the pediatric aerodigestive tract and to evaluate the associated long-term morbidity. We reviewed the medical records of 23 patients who were treated for button battery impaction at our tertiary care children's hospital from Jan. 1, 2000, through July 31, 2013. This population was made up of 14 boys and 9 girls, aged 7 days to 12 years (mean: 4 yr). Patients were divided into three groups based on the site of impaction; there were 9 impactions in the esophagus and 7 each in the nasal cavity and stomach. We compiled information on the type and size of each battery, the duration of the impaction, presenting symptoms, treatment, and outcomes. The mean duration of battery impaction was 40.6, 30.7, and 21.0 hours in the esophagus, nasal cavity, and stomach, respectively. We were able to identify the specific type of battery in 13 cases; 11 of these cases (85%) involved a 3-V 20-mm lithium ion battery, including all cases of esophageal impaction in which the type of battery was identified. The most common presenting signs and symptoms were vomiting (n = 7 [30%]), difficulty feeding (n = 5 [22%]), cough (n = 5), and bloody nasal discharge (n = 5); none of the presenting signs and symptoms predicted the severity of the injury or the outcome. The median length of hospital stay was far greater in the esophageal group (12 days) than in the nasal and stomach groups (1 day each; p = 0.006). Battery impaction in the esophagus for more than 15 hours was associated with a significantly longer postoperative hospital stay than impaction for less than 15 hours (p = 0.04). Esophageal complications included strictures (n = 5), perforation (n = 3), and tracheoesophageal fistula formation (n = 2). Clinicians should consider battery impaction in the upper aerodigestive tract as an emergency that can lead to significant long-term morbidity, and therefore immediate surgical intervention is required.