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11
result(s) for
"Guenthart, Brandon A."
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Regeneration of severely damaged lungs using an interventional cross-circulation platform
2019
The number of available donor organs limits lung transplantation, the only lifesaving therapy for the increasing population of patients with end-stage lung disease. A prevalent etiology of injury that renders lungs unacceptable for transplantation is gastric aspiration, a deleterious insult to the pulmonary epithelium. Currently, severely damaged donor lungs cannot be salvaged with existing devices or methods. Here we report the regeneration of severely damaged lungs repaired to meet transplantation criteria by utilizing an interventional cross-circulation platform in a clinically relevant swine model of gastric aspiration injury. Enabled by cross-circulation with a living swine, prolonged extracorporeal support of damaged lungs results in significant improvements in lung function, cellular regeneration, and the development of diagnostic tools for non-invasive organ evaluation and repair. We therefore propose that the use of an interventional cross-circulation platform could enable recovery of otherwise unsalvageable lungs and thus expand the donor organ pool.
Gastric aspiration severely injures donor lungs, frequently making them unacceptable for transplantation. Here the authors show that an interventional cross-circulation platform enables the regeneration of severely damaged lungs in a swine model of gastric aspiration injury.
Journal Article
Preservation of bronchial artery circulation on ex-vivo lung perfusion
by
Ruaengsri, Chawannuch
,
Choi, Ashley Y.
,
Fawad, Moeed
in
692/308/2778
,
692/308/575
,
Animal models
2025
Lungs receive blood supply from the pulmonary and bronchial arteries. After transplantation, lungs uniquely suffer from ischemia and injury to the airways, in part due to the surgical sacrifice of the bronchial artery circulation during procurement and implantation. Ex-vivo lung perfusion (EVLP) offers a platform to rehabilitate and assess donor lungs; however, it traditionally excludes bronchial circulation. We hypothesized that bronchial artery perfusion during EVLP may enhance airway preservation. A dual-circulation EVLP platform was developed using swine donor lungs with preserved bronchial arteries. Blood was separately routed to the pulmonary artery and to the bronchial arteries. Laser speckle contrast imaging (LASCA) was performed pre- and post-initiation of bronchial perfusion, and perfusion units were compared within lungs. Endpoint lung function and tissue integrity were assessed via histology and TUNEL staining after 6 h of perfusion. Six porcine lungs were successfully mounted on the dual-circulation EVLP system. Bronchial perfusion significantly increased airway perfusion (
p
= 0.03), with trends toward improved parenchymal perfusion as well. Histology demonstrated preserved architecture and less necrosis in the airways of dually perfused lungs. TUNEL staining demonstrated significantly reduced bronchial epithelial apoptosis in dual-perfused lungs compared to PA-only perfusion (
p
< 0.001). This study demonstrates the feasibility of dual-circulation EVLP in a large animal model and reveals early protective effects of bronchial artery perfusion on airway tissues. These findings suggest that incorporating bronchial perfusion into EVLP platforms may mitigate early ischemic airway injury, a key contributor to post-transplant complications and chronic lung allograft dysfunction. Further investigation is warranted to assess functional outcomes and long-term benefits, and to evaluate integration with bronchial artery revascularization strategies.
Journal Article
Intracardiac paragangliomas: surgical approach and perioperative management
by
Keeyapaj, Worasak
,
Guenthart, Brandon A.
,
Edmonson, Amanda
in
Cardiac Surgery
,
Cardiology
,
Case Report
2021
Intracardiac paragangliomas most commonly arise from the left atrium and are often infiltrative and densely adherent to surrounding structures. Given their rarity, only scattered reports exist in the literature and standardized perioperative and surgical management is not well established. We describe a case of a 60-year-old woman with a mildly functioning intracardiac paraganglioma in which division of the superior vena cava improved exposure and enabled a complex limited resection. Further, we provide an overview of the diagnostic workup, perioperative medical management, surgical approach, and surveillance strategy in patients with these challenging tumors.
Journal Article
Cross-circulation for extracorporeal support and recovery of the lung
by
Marboe, Charles
,
Romanov, Alexander
,
Bacchetta, Matthew
in
631/61/490
,
692/308/575
,
Biomedical and Life Sciences
2017
The shortage of transplantable donor organs has profound consequences, especially for patients with end-stage lung disease, for which transplantation remains the only definitive treatment. Although advances in
ex vivo
lung perfusion have enabled the evaluation and reconditioning of marginally unacceptable donor lungs, clinical use of the technique is limited to ~6 h. Extending the duration of extracorporeal organ support from hours to days would enable longer recovery and recipient-specific manipulations of the donor lung, with the goal of expanding the donor organ pool and improving long-term outcomes. By using a clinically relevant swine model, here we report the development of a cross-circulation platform wherein recipient support enabled 36 h of normothermic perfusion that maintained healthy lungs and allowed for the recovery of injured lungs. Extended support enabled multiscale therapeutic interventions in all extracorporeal lungs. Lungs exceeded transplantation criteria, and recipients tolerated cross-circulation with no significant changes in physiologic parameters throughout 36 h of support. Our findings suggest that cross-circulation should enable extended support and interventions in extracorporeal organs.
An extracorporeal cross-circulation approach enables, in a swine model, 36 hours of normothermic perfusion in healthy lungs, the recovery of injured lungs, and extended therapeutic interventions in all lungs.
Journal Article
Sound‐guided assessment and localization of pulmonary air leak
by
Mir, Seyed Mohammad
,
O'Neill, John D.
,
Kim, Jinho
in
Acoustics
,
Chronic obstructive pulmonary disease
,
digital medicine
2023
Pulmonary air leak is the most common complication of lung surgery, with air leaks that persist longer than 5 days representing a major source of post‐surgery morbidity. Clinical management of air leaks is challenging due to limited methods to precisely locate and assess leaks. Here, we present a sound‐guided methodology that enables rapid quantitative assessment and precise localization of air leaks by analyzing the distinct sounds generated as the air escapes through defective lung tissue. Air leaks often present after lung surgery due to loss of tissue integrity at or near a staple line. Accordingly, we investigated air leak sounds from a focal pleural defect in a rat model and from a staple line failure in a clinically relevant swine model to demonstrate the high sensitivity and translational potential of this approach. In rat and swine models of free‐flowing air leak under positive pressure ventilation with intrapleural microphone 1 cm from the lung surface, we identified that: (a) pulmonary air leaks generate sounds that contain distinct harmonic series, (b) acoustic characteristics of air leak sounds can be used to classify leak severity, and (c) precise location of the air leak can be determined with high resolution (within 1 cm) by mapping the sound loudness level across the lung surface. Our findings suggest that sound‐guided assessment and localization of pulmonary air leaks could serve as a diagnostic tool to inform air leak detection and treatment strategies during video‐assisted thoracoscopic surgery (VATS) or thoracotomy procedures.
Journal Article
Xenogeneic cross-circulation for extracorporeal recovery of injured human lungs
2020
Patients awaiting lung transplantation face high wait-list mortality, as injury precludes the use of most donor lungs. Although ex vivo lung perfusion (EVLP) is able to recover marginal quality donor lungs, extension of normothermic support beyond 6 h has been challenging. Here we demonstrate that acutely injured human lungs declined for transplantation, including a lung that failed to recover on EVLP, can be recovered by cross-circulation of whole blood between explanted human lungs and a Yorkshire swine. This xenogeneic platform provided explanted human lungs a supportive, physiologic milieu and systemic regulation that resulted in functional and histological recovery after 24 h of normothermic support. Our findings suggest that cross-circulation can serve as a complementary approach to clinical EVLP to recover injured donor lungs that could not otherwise be utilized for transplantation, as well as a translational research platform for immunomodulation and advanced organ bioengineering.
In a new strategy for increasing the availability of lungs for transplantation, human lungs declined for transplantation because of their poor quality can be recuperated by connecting them to the circulation of a pig.
Journal Article
Unveiling alternate pathways for SARS-CoV-2 infection via extracellular vesicle-mediated transfer of ACE2 and TMPRSS2
2026
The COVID-19 pandemic, caused by SARS-CoV-2, has underscored the urgency of understanding viral entry mechanisms to develop effective therapeutic strategies. SARS-CoV-2 primarily exploits angiotensin-converting enzyme 2 (ACE2) as its entry receptor and relies on the serine protease TMPRSS2 to prime its spike protein, enabling membrane fusion and infection. Traditionally, TMPRSS2 has been described as a cell surface protein, but our study reveals that in human lung epithelial cells, TMPRSS2 is largely absent from the plasma membrane and instead resides intracellularly. We show that TMPRSS2 is secreted together with ACE2 in extracellular vesicles (EVs) from lung epithelial cells, which are subsequently taken up by non-epithelial cells, specifically alveolar macrophages, endothelial cells, and pericytes, that do not express TMPRSS2 or ACE2 mRNAs under homeostatic conditions. This EV uptake deposits ACE2 and TMPRSS2 protein onto recipient cells, equipping them for SARS-CoV-2 entry. By transferring these viral entry proteins, EVs expand the spectrum of susceptible cell types in the lung, offering a new explanation for how the virus can infect diverse cell populations and cause widespread tissue damage. Identifying EVs as vehicles for delivering functional ACE2 and TMPRSS2 across cell types reveals a previously unrecognized pathway of viral entry with important implications for not only COVID-19 pathogenesis but also for other viral infections that exploit similar entry mechanisms. These findings open new avenues for therapeutic intervention aimed at disrupting EV-mediated protein transfer, potentially limiting viral dissemination and severity, and may also represent a generalizable mechanism exploited by other viral pathogens, highlighting the potential relevance of EV-mediated protein transfer beyond SARS-CoV-2.
Extracellular vesicles from lung epithelial cells deliver ACE2 and TMPRSS2 to recipient cells, enabling SARS-CoV-2 infection beyond receptor-expressing cells and expanding viral tropism.
Journal Article
World’s first en bloc heart-lung transplantation using the paragonix lungguard donor preservation system
by
Neto, Daniel
,
Guenthart, Brandon
,
Shudo, Yasuhiro
in
Biotechnology
,
Cardiac Surgery
,
Cardiac transplant
2023
We present the first
en bloc
heart-lung donor transplant procurement using the Paragonix LUNGguard™ donor preservation system. This system offers reliable static hypothermic conditions designed to prevent major complications such as cold ischemic injury, uneven cooling and physical damage. While this represents a single case, the encouraging results warrant further investigation.
Journal Article
JAK inhibition with tofacitinib rapidly increases contractile force in human skeletal muscle
2024
Reduction in muscle contractile force associated with many clinical conditions incurs serious morbidity and increased mortality. Here, we report the first evidence that JAK inhibition impacts contractile force in normal human muscle. Muscle biopsies were taken from patients who were randomized to receive tofacitinib (n = 16) or placebo (n = 17) for 48 h. Single-fiber contractile force and molecular studies were carried out. The contractile force of individual diaphragm myofibers pooled from the tofacitinib group (n = 248 fibers) was significantly higher than those from the placebo group (n = 238 fibers), with a 15.7% greater mean maximum specific force ( P = 0.0016). Tofacitinib treatment similarly increased fiber force in the serratus anterior muscle. The increased force was associated with reduced muscle protein oxidation and FoxO-ubiquitination–proteasome signaling, and increased levels of smooth muscle MYLK. Inhibition of MYLK attenuated the tofacitinib-dependent increase in fiber force. These data demonstrate that tofacitinib increases the contractile force of skeletal muscle and offers several underlying mechanisms. Inhibition of the JAK-STAT pathway is thus a potential new therapy for the muscle dysfunction that occurs in many clinical conditions.
Journal Article
Controlled delivery and minimally invasive imaging of stem cells in the lung
2017
Intratracheal delivery of stem cells into injured or diseased lungs can provide a variety of therapeutic and immunomodulatory effects for the treatment of acute lung injury and chronic lung disease. While the efficacy of this approach depends on delivering the proper cell dosage into the target region of the airway, tracking and analysis of the cells have been challenging, largely due to the limited understanding of cell transport and lack of suitable cell monitoring techniques. We report on the transport and deposition of intratracheally delivered stem cells as well as strategies to modulate the number of cells (e.g., dose), topographic distribution, and region-specific delivery in small (rodent) and large (porcine and human) lungs. We also developed minimally invasive imaging techniques for real-time monitoring of intratracheally delivered cells. We propose that this approach can facilitate the implementation of patient-specific cells and lead to enhanced clinical outcomes in the treatment of lung disease with cell-based therapies.
Journal Article