A Simple Cuff Technique for Murine Left Lung Transplantation.

Over the past decade, our laboratory has made significant progress in developing and refining vascularized mouse lung transplantation models using an efficient and highly reliable "cuff technique" of transplantation. This article describes a sophisticated and comprehensive method for orthotopic lung transplantation in a vascularized orthotopic lung model, representing the most physiologic and clinically relevant model of mouse lung transplantation to date. The transplantation process consists of two distinct stages: donor harvest and subsequent implantation into the recipient. The method has been successfully mastered, and with several months of sufficient training, a skilled practitioner can perform the procedure in approximately 90 min from skin-to-skin. Surprisingly, once individuals overcome the initial learning curve, the survival rate during the perioperative period approaches nearly 100%. The mouse model allows for the use of multiple commercially available transgenic and mutant strains of mice, enabling the study of tolerance and rejection. Additionally, the unique features of this model make it a valuable tool for investigating tumor biology and immunology.

Monitoring regulatory T cells as a prognostic marker in lung transplantation.

Lung transplantation is the major surgical procedure, which restores normal lung functioning and provides years of life for patients suffering from major lung diseases. Lung transplant recipients are at high risk of primary graft dysfunction, and chronic lung allograft dysfunction (CLAD) in the form of bronchiolitis obliterative syndrome (BOS). Regulatory T cell (Treg) suppresses effector cells and clinical studies have demonstrated that Treg levels are altered in transplanted lung during BOS progression as compared to normal lung. Here, we discuss levels of Tregs/FOXP3 gene expression as a crucial prognostic biomarker of lung functions during CLAD progression in clinical lung transplant recipients. The review will also discuss Treg mediated immune tolerance, tissue repair, and therapeutic strategies for achieving in-vivo Treg expansion, which will be a potential therapeutic option to reduce inflammation-mediated graft injuries, taper the toxic side effects of ongoing immunosuppressants, and improve lung transplant survival rates.

Refugee Chronicles: excerpt from the diary with an introduction.

The following text is an excerpt from The Refugee Chronicles, a fictional diary written by Evgeny Shtorn, poet and activist, from his experience of seeking asylum. Shtorn had to flee Russia due to the government's hostile policies toward both queer sexualities and political dissent right after he was interviewed by the Russian secret police FSB in 2018. The run for life and liberty brought him to the utmost end of Western Europe, Ireland. Shtorn's experience of claiming asylum made him question clear cut boundaries between the West and the East along the lines of guarantees and protections of human rights. He also noted how queer sexuality plays a specific role in the asylum application process as a protected and even desired ground for granting refugee status. His experience of a lengthy stay in the dormitory for asylum seekers converted into a book-length, semi-fictional chronicle was published by an independent press, Poryadok Slov, in St. Petersburg, Russia. The book is full of queries, ambiguities, and doubts that surround the issues of queerness, migration, and the politics of human rights. The following chapter is introduced with a short pre-word by a scholar of sexuality studies Alexander Kondakov who offers a brief contextualization and conceptualization of The Refugee Chronicles.

Treatment of hyperammonemia using in-line renal replacement and hyperosmolar therapies within an extracorporeal membrane oxygenation circuit.

After orthotopic lung transplantation, hyperammonemia can be a rare complication secondary to infection by organisms that produce urease or inhibit the urea cycle. This can cause neurotoxicity, cerebral edema, and seizures. Ammonia is unique in that it has a large volume of distribution. However, it is also readily dialyzable given its small molecular weight. As such, removal of ammonia requires renal replacement modalities that can both rapidly remove ammonia from the plasma space and allow for continuous removal to prevent rebound accumulation from intracellular stores. Prevention of iatrogenic osmotic lowering in this setting is required to prevent worsening of cerebral edema. Herein, we describe use of sequential in-line renal replacement therapy using both intermittent hemodialysis and continuous venovenous hemofiltration within an extracorporeal membrane oxygenation circuit in conjunction with higher sodium dialysate and 7.5% hypertonic saline to achieve these treatment goals.

What is the simplest model that can account for high-fidelity imitation?

What inductive biases must be incorporated into multi-agent artificial intelligence models to get them to capture high-fidelity imitation? We think very little is needed. In the right environments, both instrumental- and ritual-stance imitation can emerge from generic learning mechanisms operating on non-deliberative decision architectures. In this view, imitation emerges from trial-and-error learning and does not require explicit deliberation.

A report of 2 cases of the use of the Inari FlowTriever System in the treatment of pulmonary embolism.

The FlowTriever System (Inari Medical, Irvine, California) is the first FDA-approved mechanical thrombectomy device used for treatment of pulmonary embolism. This device enables nonsurgical removal of pulmonary blood clots without the use of thrombolytic medication and its associated risks. We report 2 cases of successful application of the Inari FlowTriever in treatment of pulmonary embolism and right atrial thrombus.

Learning agents that acquire representations of social groups.

Humans are learning agents that acquire social group representations from experience. Here, we discuss how to construct artificial agents capable of this feat. One approach, based on deep reinforcement learning, allows the necessary representations to self-organize. This minimizes the need for hand-engineering, improving robustness and scalability. It also enables "virtual neuroscience" research on the learned representations.

Loss of stromal cell Thy-1 plays a critical role in lipopolysaccharide induced chronic lung allograft dysfunction.

BACKGROUND: Long-term survival of lung transplants lags behind other solid organs due to early onset of a fibrotic form of chronic rejection known as chronic lung allograft dysfunction (CLAD). Preventing CLAD is difficult as multiple immunologic and physiologic insults contribute to its development. Targeting fibroblast activation, which is the final common pathway leading to CLAD, offers the opportunity to ameliorate fibrosis irrespective of the initiating insult. Thy-1 is a surface glycoprotein that controls fibroblast differentiation and activation. METHODS: To study the role of Thy-1 in CLAD, we utilized the minor antigen mismatched C57BL/6 (B6wild-type) or B6Thy-1-/-→C57BL/10 (B10) model of murine orthotopic lung transplantation with postoperative bacterial infection modeled by intratracheal lipopolysaccharide (LPS) administration. The effects of LPS on Thy-1 expression, proliferation, and gene expression were assessed in fibroblasts in vitro and the therapeutic potential of Thy-1 replacement was assessed in vivo. RESULTS: More severe CLAD was evident in B6Thy-1-/- →B10 grafts compared to B6wild-type →B10 grafts. LPS further accentuated fibrosis in B6wild-type →B10 grafts with some, but limited, effects on B6Thy-1-/- →B10 grafts. LPS contributed to Thy-1 loss from Thy-1(+) fibroblasts in vitro due to a decrease in mRNA expression. In addition, LPS promoted proliferation and upregulation of multiple inflammatory pathways in Thy-1(-) fibroblasts by gene expression analysis. Most importantly, replacement of Thy-1 through exogenous administration ameliorated the fibrotic phenotype post-LPS mediated modeling of infection. CONCLUSIONS: Our findings suggest that the loss of Thy-1 on fibroblasts is a previously unrecognized cause of CLAD and its replacement may offer therapeutic applications for amelioration of this disease post-transplantation in the setting of infectious stress responses.

Ischemia reperfusion injury facilitates lung allograft acceptance through IL-33-mediated activation of donor-derived IL-5 producing group 2 innate lymphoid cells.

Pathways regulating lung alloimmune responses differ from most other solid organs and remain poorly explored. Based on our recent work identifying the unique role of eosinophils in downregulating lung alloimmunity, we sought to define pathways contributing to eosinophil migration and homeostasis. Using a murine lung transplant model, we have uncovered that immunosuppression increases eosinophil infiltration into the allograft in an IL-5-dependent manner. IL-5 production depends on immunosuppression-mediated preservation of donor-derived group 2 innate lymphoid cells (ILC2). We further describe that ischemia reperfusion injury upregulates the expression of IL-33, which functions as the dominant and nonredundant mediator of IL-5 production by graft-resident ILC2. Our work thus identifies unique cellular mechanisms that contribute to lung allograft acceptance. Notably, ischemia reperfusion injury, widely considered to be solely deleterious to allograft survival, can also downregulate alloimmune responses by initiating unique pathways that promote IL-33/IL-5/eosinophil-mediated tolerance.

Solving the Conundrum of Eosinophils in Alloimmunity.

Eosinophils are bone-marrow-derived granulocytes known for their ability to facilitate clearance of parasitic infections and their association with asthma and other inflammatory diseases. The purpose of this review is to discuss the currently available human observational and animal experimental data linking eosinophils to the immunologic response in solid organ transplantation. First, we present observational human studies that demonstrate a link between transplantation and eosinophils yet were unable to define the exact role of this cell population. Next, we describe published experimental models and demonstrate a defined mechanistic role of eosinophils in downregulating the alloimmune response to murine lung transplants. The overall summary of this data suggests that further studies are needed to define the role of eosinophils in multiple solid organ allografts and points to the possibility of manipulating this cell population to improve graft survival.

Management of Pediatric Post-Concussion Headaches: National Survey of Abortive Therapies Used in the Emergency Department.

Children frequently present to an Emergency Department (ED) after concussion, and headache is the most commonly associated symptom. Recent guidelines emphasize the importance of analgesia for post-concussion headache (PCH), yet evidence to inform treatment is lacking. We sought to characterize abortive therapies used to manage refractory PCH in the pediatric ED and factors associated with treatment. A scenario-based survey was distributed to ED physicians at all 15 Canadian tertiary pediatric centers. Participants were asked questions regarding ED treatment of acute (48 h) and persistent (1 month) PCH refractory to appropriate doses of acetaminophen/ibuprofen. Logistic regression was used to assess factors associated with treatment. Response rate was 63% (137/219). Nearly all physicians (128/137, 93%) endorsed treatment in the ED for acute PCH of severe intensity, with most selecting intravenous treatments (116/137, 84.7%). Treatments were similar for acute and persistent PCH. The most common treatments were metoclopramide (72%), physiologic saline (47%), and nonsteroidal anti-inflammatory agents (NSAIDS; 35%). Second-line ED treatments were more variable. For acute PCH of moderate intensity, overall treatment was lower (102/137, 74%; p < 0.0001), and NSAIDS (48%) were most frequently selected. In multi-variable regression analyses, no physician- or ED-level factor was associated with receiving treatment, or treatment using metoclopramide specifically. Treatment for refractory PCH in the pediatric ED is highly variable. Importantly, patients with severe PCH are most likely to receive intravenous therapies, often with metoclopramide, despite a paucity of evidence supporting these choices. Further research is urgently needed to establish the comparative effectiveness of pharmacotherapeutic treatments for children with refractory PCH.

Retargeting IL-2 Signaling to NKG2D-Expressing Tumor-Infiltrating Leukocytes Improves Adoptive Transfer Immunotherapy.

Ex vivo expansion followed by reinfusion of tumor-infiltrating leukocytes (TILs) has been used successfully for the treatment of multiple malignancies. Most protocols rely on the use of the cytokine IL-2 to expand TILs prior to reinfusion. In addition, TIL administration relies on systemic administration of IL-2 after reinfusion to support transferred cell survival. The use of IL-2, however, can be problematic because of its preferential expansion of regulatory T and myeloid cells as well as its systemic side effects. In this study, we describe the use of a novel IL-2 mutant retargeted to NKG2D rather than the high-affinity IL-2R for TIL-mediated immunotherapy in a murine model of malignant melanoma. We demonstrate that the NKG2D-retargeted IL-2 (called OMCPmutIL-2) preferentially expands TIL-resident CTLs, such as CD8+ T cells, NK cells, and γδT cells, whereas wild-type IL-2 provides a growth advantage for CD4+Foxp3+ T cells as well as myeloid cells. OMCPmutIL-2-expanded CTLs express higher levels of tumor-homing receptors, such as LFA-1, CD49a, and CXCR3, which correlate with TIL localization to the tumor bed after i.v. injection. Consistent with this, OMCPmutIL-2-expanded TILs provided superior tumor control compared with those expanded in wild-type IL-2. Our data demonstrate that adoptive transfer immunotherapy can be improved by rational retargeting of cytokine signaling to NKG2D-expressing CTLs rather than indiscriminate expansion of all TILs.

Patient-Reported Experience in the Pediatric Emergency Department: What Matters Most?

INTRODUCTION: Although the Child Hospital Consumer Assessment of Healthcare Providers and Systems is a validated tool for the inpatient experience, it may not address features unique to the pediatric emergency department (PED). There is currently no publicly available validated patient-reported experience survey for the PED, and what matters most in this setting remains unknown. METHODS: Twelve semistructured interviews were conducted with a convenience sample of parents of children younger than 14 years at a Canadian PED. Data analysis was performed using inductive thematic analysis to identify aspects of patient-reported experiences that matter most to parents in the PED. RESULTS: Five themes were identified: (1) making waiting a positive experience, (2) taking the time to provide care, (3) forging a positive partnership, (4) speak up for safe care, and (5) making the environment feel safer. Parents highlighted that while waiting for care is not desirable, it is made more acceptable through the communication of wait time estimates and the presence of child activities in the waiting room. Furthermore, although interactions with providers are brief, parents emphasized the importance of creating an environment of partnership with open communication, taking the time to examine their child, and actively demonstrating the provision of safe, quality care. CONCLUSIONS: Results from this study suggest that a patient-reported experience survey in the PED may need to embed elements not currently captured in Child Hospital Consumer Assessment of Healthcare Providers and Systems, such as waiting room experience, comprehensiveness of health assessments, and observations of safety measures. Future studies can use these findings to develop a patient-reported experience survey for use in the PED.

Feasibility of Early Active Rehabilitation for Concussion Recovery in Youth: A Randomized Trial.

OBJECTIVE: The primary objective is to evaluate the feasibility (safety and acceptability) of implementing early active rehabilitation (AR) for concussion management in youth with symptoms persisting 2 weeks after injury. A secondary and exploratory objective was to estimate the potential efficacy of early AR compared with standard AR. We hypothesize that AR at 2-weeks postconcussion will be safe and acceptable to patients. DESIGN: Randomized clinical trial. SETTING: The Montreal Children's Hospital of the McGill University Health Center (MCH-MUHC), a tertiary care pediatric teaching hospital affiliated with McGill University in Montreal, Canada. PARTICIPANTS: Twenty youth aged 9 to 17 years old with postconcussion symptoms for at least 2 weeks. INTERVENTION: Active rehabilitation (aerobic exercise, coordination drills, visualization, and education/reassurance) was administered by physiotherapists in-person, and then continued as a home program. METHODS: Twenty participants were randomized to either early AR (initiated 2 weeks after injury) or standard AR (initiated 4 weeks after injury). RESULTS: Two adverse events (one in each group) were identified through an online survey more than one-month postconcussion. Postconcussion symptoms decreased over time for both groups. CONCLUSIONS: The results from this pilot study indicate that a full clinical trial estimating the efficacy of early AR (starting 2 weeks after injury) is feasible. Further study is needed to determine the superiority of this strategy over current treatment approaches.