Rational Viral myocarditis is a life-threatening illness that may lead to heart failure or cardiac arrhythmias. A major causative agent for viral myocarditis is the B3 strain of coxsackievirus, a positive-sense RNA enterovirus. However, human cardiac tissues are difficult to procure in sufficient enough quantities for studying the mechanisms of cardiac-specific viral infection. Objective This study examined whether human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) could be used to model the pathogenic processes of coxsackievirus-induced viral myocarditis and to screen antiviral therapeutics for efficacy. Methods and Results Human iPSC-CMs were infected with a luciferase-expressing coxsackievirus B3 strain (CVB3-Luc). Brightfield microscopy, immunofluorescence, and calcium imaging were utilized to characterize virally-infected hiPSC-CMs for alterations in cellular morphology and calcium handling. Viral proliferation in hiPSC-CMs was quantified using bioluminescence imaging. Antiviral compounds including interferon beta 1 (IFNβ1), ribavirin, pyrrolidine dithiocarbamate, and fluoxetine were tested for their capacity to abrogate CVB3-Luc proliferation in hiPSC-CMs in vitro. The ability of these compounds to reduce CVB3-Luc proliferation in hiPSC-CMs was consistent with reported drug effects in previous studies. Mechanistic analyses via gene expression profiling of hiPSC-CMs infected with CVB3-Luc revealed an activation of viral RNA and protein clearance pathways after IFNβ1 treatment. Conclusions This study demonstrates that hiPSC-CMs express the coxsackievirus and adenovirus receptor, are susceptible to coxsackievirus infection, and can be used to predict antiviral drug efficacy. Our results suggest that the hiPSC-CM/CVB3-Luc assay is a sensitive platform that can screen novel antiviral therapeutics for their effectiveness in a high-throughput fashion.

Short Abstract Here, we describe a robust protocol for human cardiomyocyte derivation that combines small molecule-modulated cardiac differentiation and glucose deprivation-mediated cardiomyocyte purification, enabling production of purified cardiomyocytes for the purposes of cardiovascular disease modeling and drug screening. Long Abstract Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have become an important cell source to address the lack of primary cardiomyocytes available for basic research and translational applications. To differentiate hiPSCs into cardiomyocytes, various protocols including embryoid body (EB)-based differentiation and growth factor induction have been developed. However, these protocols are inefficient and highly variable in their ability to generate purified cardiomyocytes. Recently, a small molecule-based protocol utilizing modulation of Wnt/β-Catenin signaling was shown to promote cardiac differentiation with high efficiency. With this protocol, greater than 50–60% of differentiated cells were cardiac troponin-positive cardiomyocytes were consistently observed. To further increase cardiomyocyte purity, the differentiated cells were subjected to glucose starvation to specifically eliminate non-cardiomyocytes based on the metabolic differences between cardiomyocytes and non-cardiomyocytes. Using this selection strategy, we consistently obtained a greater than 30% increase in the ratio of cardiomyocytes to non-cardiomyocytes in a population of differentiated cells. These highly purified cardiomyocytes should enhance the reliability of results from human iPSC-based in vitro disease modeling studies and drug screening assays.

Learning Objectives: After studying this article, the participant should be able to: 1. Describe the pathogenesis of hidradenitis suppurativa. 2. Discuss perioperative multimodal therapy of hidradenitis suppurativa, including medical optimization. 3. Determine an appropriate surgical plan with excision and reconstruction based on hidradenitis suppurativa severity, size, and anatomical location. Summary: Successful treatment of hidradenitis suppurativa requires a multidisciplinary team approach and multimodal therapy.

As a global crisis, COVID-19 has underscored the challenge of disseminating evidence-based public health recommendations amidst a rapidly evolving, often uncensored information ecosystem—one fueled in part by an unprecedented degree of connected afforded through social media. In this piece, we explore an underdiscussed intersection between the visual arts and public health, focusing on the use of validated infographics and other forms of visual communication to rapidly disseminate accurate public health information during the COVID-19 pandemic. We illustrate our arguments through our own experience in creating a validated infographic for patients, now disseminated through social media and other outlets across the world in nearly 20 translations. Visual communication offers a creative and practical medium to bridge critical health literacy gaps, empower diverse patient communities through evidence-based information and facilitate public health advocacy during this pandemic and the ‘new normal’ that lies ahead.

Learning Objectives: After studying this article, the participant should be able to: 1. Describe the pathogenesis, classification, and risk factors of sternal wound infection. 2. Discuss options for sternal stabilization for the prevention of sternal wound infection, including wiring and plating techniques. 3. Discuss primary surgical reconstructive options for deep sternal wound infection and the use of adjunctive methods, such as negative-pressure wound therapy. Summary: Poststernotomy sternal wound infection remains a life-threatening complication of open cardiac surgery. Successful treatment relies on timely diagnosis and initiation of multidisciplinary, multimodal therapy. (Plast.

Therapeutic strategies that successfully combine two techniques—autologous micrografting and biodegradable scaffolds—offer great potential for improved wound repair and decreased scarring. In this study we evaluate the efficacy of a novel modification of a collagen-glycosaminoglycan (collagen-GAG) scaffold with autologous micrografts using a murine dorsal wound model. db/db mice underwent a full thickness 1.0 cm2 dorsal wound excision and were treated with a collagen-GAG scaffold (CGS group), a modified collagen-GAG scaffold (CGS + MG group) or simple occlusive dressing (Blank group). The modified scaffold was created by harvesting full thickness micrografts and transplanting these into the collagen-GAG membrane. Parameters of wound healing, including cellular proliferation, collagen deposition, keratinocyte migration, and angiogenesis were assessed. The group treated with the micrograft-modified scaffold healed at a faster rate, showed greater cellular proliferation, collagen deposition, and keratinocyte migration with higher density and greater maturity of microvessels. The grafts remained viable within the scaffold with no evidence of rejection. Keratinocytes were shown to migrate from the wound border and from the micrograft edges towards the center of the wound, while cellular proliferation was present both at the wound border and wound bed. We report successful treatment of diabetic wounds with a novel collagen-GAG scaffold modified with full-thickness automicrografts. Differences in cellular migration and proliferation offer maiden evidence on the mechanisms of wound healing. Clinically, the successful scaffold engraftment, micrograft viability and improved wound healing offer promising results for the development of a new therapeutic modality for wound repair.

Direct reprogramming of somatic cells has been demonstrated, however, it is unknown whether electrophysiologically-active somatic cells derived from separate germ layers can be interconverted. We demonstrate that partial direct reprogramming of mesoderm-derived cardiomyocytes into neurons is feasible, generating cells exhibiting structural and electrophysiological properties of both cardiomyocytes and neurons. Human and mouse pluripotent stem cell-derived CMs (PSC-CMs) were transduced with the neurogenic transcription factors Brn2, Ascl1, Myt1l and NeuroD. We found that CMs adopted neuronal morphologies as early as day 3 post-transduction while still retaining a CM gene expression profile. At week 1 post-transduction, we found that reprogrammed CMs expressed neuronal markers such as Tuj1, Map2, and NCAM. At week 3 post-transduction, mature neuronal markers such as vGlut and synapsin were observed. With single-cell qPCR, we temporally examined CM gene expression and observed increased expression of neuronal markers Dcx, Map2, and Tubb3. Patch-clamp analysis confirmed the neuron-like electrophysiological profile of reprogrammed CMs. This study demonstrates that PSC-CMs are amenable to partial neuronal conversion, yielding a population of cells exhibiting features of both neurons and CMs.

Summary Diffuse cutaneous nerve injuries, often caused by a crush mechanism, are challenging for the nerve surgeon. Discrete nerve transections and focal neuromas are easier to identify and have a more distinct treatment algorithm. Following crush injury to a noncritical sensory nerve, a successful local anesthetic block proximal to the injury may help determine the possibility of surgical intervention. In these cases, we describe a technique of “reset neurectomy” whereby a neurectomy is performed proximal to the zone of injury, and immediate repair or reconstruction (with or without a nerve graft) is performed. This technique may be useful in cases of diffuse, nontransection nerve injuries in which neuropathic pain is the primary symptom.