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The accumulation of myofibroblasts within the intimal layer of inflamed blood vessels is a potentially catastrophic complication of vasculitis, which can lead to arterial stenosis and ischaemia. In this study, we have investigated how these luminal myofibroblasts develop during Kawasaki disease (KD), a paediatric vasculitis typically involving the coronary arteries. By performing lineage tracing studies in a murine model of KD, we reveal that luminal myofibroblasts develop independently of adventitial fibroblasts and endothelial cells, and instead derive from smooth muscle cells (SMCs). Notably, the emergence of SMC-derived luminal myofibroblasts-in both mice and patients with KD, Takayasu's arteritis and Giant Cell arteritis-coincided with activation of the mechanistic target of rapamycin (mTOR) signalling pathway. Moreover, SMC-specific deletion of mTOR signalling, or pharmacological inhibition, abrogated the emergence of luminal myofibroblasts. Thus, mTOR is an intrinsic and essential regulator of luminal myofibroblast formation that is activated in vasculitis patients and therapeutically tractable. These findings provide molecular insight into the pathogenesis of coronary artery stenosis and identify mTOR as a therapeutic target in vasculitis., (© 2024. The Author(s).)

There are many different kinds of 'phantom' percepts but it is unknown whether they are united by common mechanisms. For example, synaesthesia (e.g., numbers evoking colour) and hallucinations appear conceptually and phenomenologically similar: both result in a percept that does not have an environmental correlate. Here, people with synaesthesia (n = 66) performed a conditioned hallucinations paradigm known to be sensitive to hallucination susceptibility, and we asked whether synaesthetes would show the same behavioural profile as hallucinators in this task. Repeated pairing of checkerboards with tones, and gratings with colours encourages the participant to draw on prior knowledge when asked to report on the presence of the difficult-to-detect target stimulus. Synaesthetes show increased modelled expectancies for the stimulus association across the board, resulting in a higher number of detections at all stimulus intensities. This is in contrast to the pattern observed in hallucinators, who weigh their prior beliefs more strongly than controls, giving rise to more conditioned hallucinations. Results indicate that fundamentally different perceptual processes may be at the core of these seemingly similar experiences., (© 2024. The Author(s).)

To demonstrate that point-of-care multimodal spectroscopy using Near-Infrared (NIR) and Raman Spectroscopy (RS) can be used to diagnose human heart tissue. We generated 105 spectroscopic scans, which comprised 4 NIR and 3 RS scans per sample to generate a "multimodal spectroscopic scan" (MSS) for each heart, done across 15 patients, 5 each from the dilated cardiomyopathy (DCM), Ischaemic Heart Disease (IHD) and Normal pathologies. Each of the MSS scans was undertaken in 3 s. Data were entered into machine learning (ML) algorithms to assess accuracy of MSS in diagnosing tissue type. The median age was 50 years (IQR 49-52) for IHD, 47 (IQR 45-50) for DCM and 36 (IQR 33-52) for healthy patients (p = 0.35), 60% of which were male. MSS identified key differences in IHD, DCM and normal heart samples in regions typically associated with fibrosis and collagen (NIR wavenumbers: 1433, 1509, 1581, 1689 and 1725 nm; RS wavelengths: 1658, 1450 and 1330 cm -1 ). In principal component (PC) analyses, these differences explained 99.2% of the variation in 4 PCs for NIR, 81.6% in 10 PCs for Raman, and 99.0% in 26 PCs for multimodal spectroscopic signatures. Using a stack machine learning algorithm with combined NIR and Raman data, our model had a precision of 96.9%, recall of 96.6%, specificity of 98.2% and Area Under Curve (AUC) of 0.989 (Table 1). NIR and Raman modalities alone had similar levels of precision at 94.4% and 89.8% respectively (Table 1). MSS combined with ML showed accuracy of 90% for detecting dilated cardiomyopathy, 100% for ischaemic heart disease and 100% for diagnosing healthy tissue. Multimodal spectroscopic signatures, based on NIR and Raman spectroscopy, could provide cardiac tissue scans in 3-s to aid accurate diagnoses of fibrosis in IHD, DCM and normal hearts. Table 1 Machine learning performance metrics for validation data sets of (a) Near-Infrared (NIR), (b) Raman and (c and d) multimodal data using logistic regression (LR), stochastic gradient descent (SGD) and support vector machines (SVM), with combined "stack" (LR + SGD + SVM) AUC Precision Recall Specificity (a) NIR model  Logistic regression 0.980 0.944 0.933 0.967  SGD 0.550 0.281 0.400 0.700  SVM 0.840 0.806 0.800 0.900  Stack 0.933 0.794 0.800 0.900 (b) Raman model  Logistic regression 0.985 0.940 0.929 0.960  SGD 0.892 0.869 0.857 0.932  SVM 0.992 0.940 0.929 0.960  Stack 0.954 0.869 0.857 0.932 (c) MSS: multimodal (NIR + Raman) to detect DCM vs. IHD vs. normal patients  Logistic regression 0.975 0.841 0.828 0.917  SGD 0.847 0.803 0.793 0.899  SVM 0.971 0.853 0.828 0.917  Stack 0.961 0.853 0.828 0.917 (d) MSS: multimodal (NIR + Raman) to detect pathological vs. normal patients  Logistic regression 0.961 0.969 0.966 0.984  SGD 0.944 0.967 0.966 0.923  SVM 1.000 1.000 1.000 1.000  Stack 1.000 0.944 0.931 0.969 Bold values indicate values obtained from the stack algorithm and used for analyses., (© 2023. Crown.)

Introduction: Visual assessment and imaging of the donor liver are inaccurate in predicting fibrosis and remain surrogates for histopathology. We demonstrate that 3-s scans using a handheld near-infrared-spectroscopy (NIRS) instrument can identify and quantify fibrosis in fresh human liver samples., Methods: We undertook NIRS scans on 107 samples from 27 patients, 88 from 23 patients with liver disease, and 19 from four organ donors., Results: Liver disease patients had a median immature fibrosis of 40% (interquartile range [IQR] 20-60) and mature fibrosis of 30% (10%-50%) on histopathology. The organ donor livers had a median fibrosis (both mature and immature) of 10% (IQR 5%-15%). Using machine learning, this study detected presence of cirrhosis and METAVIR grade of fibrosis with a classification accuracy of 96.3% and 97.2%, precision of 96.3% and 97.0%, recall of 96.3% and 97.2%, specificity of 95.4% and 98.0% and area under receiver operator curve of 0.977 and 0.999, respectively. Using partial-least square regression machine learning, this study predicted the percentage of both immature ( R 2  = 0.842) and mature ( R 2  = 0.837) with a low margin of error (root mean square of error of 9.76% and 7.96%, respectively)., Conclusion: This study demonstrates that a point-of-care NIRS instrument can accurately detect, quantify and classify liver fibrosis using machine learning., Competing Interests: The authors declare no conflict of interest., (© 2023 The Authors. Health Science Reports published by Wiley Periodicals LLC.)

Background: Consent rates for organ donation conversations (ODCs) vary. We hypothesised that a simple grading system could identify challenging ODCs. We further hypothesised that challenging ODCs would have higher consent rates when conducted by ODC specialists. Objectives: We aimed to study the utility of a grading system for ODCs and test the hypothesis that any training effect would be associated with improved consent rates in ODCs graded as most challenging. Methods: We stratified 2017 Australian DonateLife Audit aggregate consent and donation discussion data into four ODC grades based on Australian Organ Donor Register (AODR) status and person first raising the topic of organ donation. Grade I: "yes" present on AODR and family-raised organ donation; Grade II: "yes" present on AODR, and clinician-raised organ donation; Grade III: no registration on AODR but family-raised organ donation; and Grade IV: no registration on AODR, and clinician-raised organ donation. Results: Grade I ODCs were uncommon 7.7% (109/1420), with a consent rate of 95.4% (104/109). Grade IV ODCs were frequent (60.4%, 857/1420), with a consent rate of 41.4% (355/857). However, in Grade IV ODCs, organ donation specialist consent rate was 53.5% (189/353), significantly greater than for other trained staff at 33.1% (88/266) ( P < 0.005; odds ratio [OR], 2.33; 95% CI, 1.68-3.24) or untrained requestors at 32.8% (78/238; P < 0.005; OR, 2.36; 95% CI. 1.68-3.33). Conclusion: The likelihood of consent can be predicted using readily available variables. This allows prospective identification of Grade IV ODCs, which carry low but potentially modifiable likelihood of consent. Involving donation specialists was associated with more consents for organ donation when applied retrospectively to Australian audit data., Competing Interests: None declared., (© 2020 College of Intensive Care Medicine of Australia and New Zealand.)

Tissue-resident memory T (T RM ) cells provide immune defense against local infection and can inhibit cancer progression. However, it is unclear to what extent chronic inflammation impacts T RM activation and whether T RM cells existing in tissues before tumor onset influence cancer evolution in humans. We performed deep profiling of healthy lungs and lung cancers in never-smokers (NSs) and ever-smokers (ESs), finding evidence of enhanced immunosurveillance by cells with a T RM -like phenotype in ES lungs. In preclinical models, tumor-specific or bystander T RM -like cells present prior to tumor onset boosted immune cell recruitment, causing tumor immune evasion through loss of MHC class I protein expression and resistance to immune checkpoint inhibitors. In humans, only tumors arising in ES patients underwent clonal immune evasion, unrelated to tobacco-associated mutagenic signatures or oncogenic drivers. These data demonstrate that enhanced T RM -like activity prior to tumor development shapes the evolution of tumor immunogenicity and can impact immunotherapy outcomes., Competing Interests: Declaration of interests C.S. acknowledges grant support from AstraZeneca, Boehringer-Ingelheim, Bristol-Myers Squibb, Pfizer, Roche-Ventana, Invitae (previously Archer Dx Inc–collaboration in minimal residual disease sequencing technologies), and Ono Pharmaceutical. C.S. is an AstraZeneca Advisory Board member and Chief Investigator for the AZ MeRmaiD 1 and 2 clinical trials and is also Co-Chief Investigator of the NHS Galleri trial funded by GRAIL and a paid member of GRAIL’s SAB. He receives consultant fees from Achilles Therapeutics (also SAB member), Bicycle Therapeutics (also a SAB member), Genentech, Medicxi, Roche Innovation Centre– Shanghai, Metabomed (until July 2022), and the Sarah Cannon Research Institute. He had stock options in Apogen Biotechnologies and GRAIL until June 2021, and currently has stock options in Epic Bioscience, Bicycle Therapeutics, and has stock options and is co-founder of Achilles Therapeutics. C.S. is an inventor on a European patent application relating to assay technology to detect tumour recurrence (PCT/GB2017/053289), the patent has been licensed to commercial entities, and under his terms of employment, C.S. is due a revenue share of any revenue generated from such licence(s). C.S. holds patents relating to targeting neoantigens (PCT/EP2016/059401), identifying patient response to immune checkpoint blockade (PCT/EP2016/071471), determining HLA LOH (PCT/GB2018/052004), predicting survival rates of patients with cancer (PCT/GB2020/050221), identifying patients who respond to cancer treatment (PCT/GB2018/051912), a US patent relating to detecting tumour mutations (PCT/US2017/28013), methods for lung cancer detection (US20190106751A1) and both a European and US patent related to identifying insertion/deletion mutation targets (PCT/GB2018/051892) and is co-inventor to a patent application to determine methods and systems for tumour monitoring (PCT/EP2022/077987). C.S has received honoraria from Amgen, AstraZeneca, Pfizer, Novartis, GlaxoSmithKline, MSD, Bristol Myers Squibb, Illumina, and Roche-Ventana., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objective: Remodeling of the coronary arteries is a common feature in severe cases of Kawasaki disease (KD). This pathology is driven by the dysregulated proliferation of vascular fibroblasts, which can lead to coronary artery aneurysms, stenosis, and myocardial ischemia. We undertook this study to investigate whether inhibiting fibroblast proliferation might be an effective therapeutic strategy to prevent coronary artery remodeling in KD., Method: We used a murine model of KD (induced by the injection of the Candida albicans water-soluble complex [CAWS]) and analyzed patient samples to evaluate potential antifibrotic therapies for KD., Results: We identified the mechanistic target of rapamycin (mTOR) pathway as a potential therapeutic target in KD. The mTOR inhibitor rapamycin potently inhibited cardiac fibroblast proliferation in vitro, and vascular fibroblasts up-regulated mTOR kinase signaling in vivo in the CAWS mouse model of KD. We evaluated the in vivo efficacy of mTOR inhibition and found that the therapeutic administration of rapamycin reduced vascular fibrosis and intimal hyperplasia of the coronary arteries in CAWS-injected mice. Furthermore, the analysis of cardiac tissue from KD fatalities revealed that vascular fibroblasts localizing with inflamed coronary arteries up-regulate mTOR signaling, confirming that the mTOR pathway is active in human KD., Conclusion: Our findings demonstrate that mTOR signaling contributes to coronary artery remodeling in KD, and that targeting this pathway offers a potential therapeutic strategy to prevent or restrict this pathology in high-risk KD patients., (© 2022 American College of Rheumatology.)

We aimed to facilitate the donation of tissue samples for research by establishing a centralized system integrated in the organ donation program for collection, storage, and distribution of samples (the Australian Donation and Transplantation Biobank [ADTB])., Methods: Feasibility of a research biobank integrated within the deceased organ and tissue donation program was assessed. DonateLife Victoria sought consent for ADTB donation after consent was received for organ donation for transplantation from the donor's senior available next of kin. ADTB samples were collected during donation surgery and distributed fresh to researchers or stored for future research. The main outcome measures were ADTB donation rates, ADTB sample collection, ADTB sample use, and to identify ethical considerations., Results: Over 2 y, samples were collected for the ADTB from 69 donors (28% of 249 donors). Samples were obtained from the spleen (n = 59, 86%), colon (n = 57, 83%), ileum (n = 56, 82%), duodenum (n = 55, 80%), blood (n = 55, 80%), bone marrow (n = 55, 80%), skin (n = 54, 78%), mesenteric lymph nodes (n = 56, 81%), liver (n = 21, 30%), lung (n = 29, 42%), and lung-draining lymph node (n = 29, 42%). Heart (n = 20), breast (n = 1), and lower urinary tract (n = 1) samples were obtained in the second year. Five hundred fifty-six samples were used in 19 ethics-approved research projects spanning the fields of immunology, microbiology, oncology, anatomy, physiology, and surgery., Conclusions: The integration of routine deceased donation and transplantation activities with a coordinated system for retrieval and allocation of donor samples for use in a range of research projects is feasible and valuable., Competing Interests: The authors declare no conflicts of interest, (Copyright © 2022 The Author(s). Transplantation Direct. Published by Wolters Kluwer Health, Inc.)

Lung transplantation is limited by a lack of suitable lung donors. In Australia, the national donation organisation (DonateLife) has taken a major role in optimising organ donor identification. However, the potential outside the DonateLife network hospitals remains uncertain. We aimed to create a prediction model for lung donation within the DonateLife network and estimate the untapped lung donors outside of the DonateLife network. We reviewed all deaths in the state of Victoria's intensive care units using a prospectively collected population-based intensive care unit database linked to organ donation records. A logistic regression model derived using patient-level data was developed to characterise the lung donors within DonateLife network hospitals. Consequently, we estimated the expected number of lung donors in Victorian hospitals outside the DonateLife network and compared the actual number. Between 2014 and 2018, 291 lung donations occurred from 8043 intensive care unit deaths in DonateLife hospitals, while only three lung donations occurred from 1373 ICU deaths in non-DonateLife hospitals. Age, sex, postoperative admission, sepsis, neurological disease, trauma, chronic respiratory disease, lung oxygenation and serum creatinine were factors independently associated with lung donation. A highly discriminatory prediction model with area under the receiver operator characteristic curve of 0.91 was developed and accurately estimated the number of lung donors. Applying the model to non-DonateLife hospital data predicted only an additional five lung donors. This prediction model revealed few additional lung donor opportunities outside the DonateLife network, and the necessity of alternative and novel strategies for lung donation. A donor prediction model could provide a useful benchmarking tool to explore organ donation potential across different jurisdictions, hospitals and transplanting centres.

Purpose: To compare nutrition and health outcomes before and after implementing a standardized enteral feeding protocol on nutrition and health outcomes in very low birth weight preterm infants. Methods: A retrospective chart review was performed evaluating preterm infants, born less than 34 weeks gestation and weighing less than 1500 g, before and after the implementation of a standardized enteral feeding protocol. Outcomes included weaning of parenteral nutrition, initiation and advancement of enteral feeds, initiation of human-milk fortifier (HMF), change in weight z -score and neonatal morbidities. Results: Fifty-six infants (30 in pre-group, 26 in post-group) met the inclusion criteria. Infants in the standardized enteral feeding protocol group started enteral feeds earlier ( p  = 0.039) and received full HMF fortification at lower weights ( p  = 0.033) than those in the pre-group. Fewer days on continuous positive airway pressure ( p  = 0.021) and lower rates of bronchopulmonary dysplasia ( p  = 0.018) were also observed in the post-group. Weaning of parenteral nutrition and weight z -score were not significantly different between groups. There were no differences in other morbidities. Conclusion: Study results suggest that adopting a standardized enteral feeding protocol may promote early initiation of enteral feeds and fortification.

Objective: Vasculitis is characterised by inflammation of the blood vessels. While all layers of the vessel can be affected, inflammation within the intimal layer can trigger thrombosis and arterial occlusion and is therefore of particular clinical concern. Given this pathological role, we have examined how intimal inflammation develops by exploring which (and how) macrophages come to populate this normally immune-privileged site during vasculitis., Methods: We have addressed this question for Kawasaki disease (KD), which is a type of vasculitis in children that typically involves the coronary arteries. We used confocal microscopy and flow cytometry to characterise the macrophages that populate the coronary artery intima in KD patient samples and in a mouse model of KD, and furthermore, have applied an adoptive transfer system to trace how these intimal macrophages develop., Results: In KD patients, intimal hyperplasia coincided with marked macrophage infiltration of the coronary artery intima. Phenotypic analysis revealed that these 'intimal macrophages' did not express markers of resident cardiac macrophages, such as Lyve-1, and instead, were uniformly positive for the chemokine receptor Ccr2, suggesting a monocytic lineage. In support of this origin, we show that circulating monocytes directly invade the intima via transluminal migration during established disease, coinciding with the activation of endothelial cells lining the coronary arteries., Conclusions: During KD, intimal macrophages develop from circulating monocytes that infiltrate the inflamed coronary artery intima by transluminal migration., Competing Interests: IPW has received funding from CSL and Med‐Immune for research on cytokine antagonists. The remaining authors declare no conflict of interest., (© 2022 The Authors. Clinical & Translational Immunology published by John Wiley & Sons Australia, Ltd on behalf of Australian and New Zealand Society for Immunology, Inc.)

Background: In Australia, increased organ donation and subsequent lung transplantation (LTx) rates have followed enhanced donor identification, referral and management, as well as the introduction of a donation after circulatory death (DCD) pathway. However, the number of patients waiting for LTx still continues to exceed the number of lung donors and the search for further suitable donors is critical., Methods: All 2014-2018 Victorian DonateLife hospital deaths after intensive care unit (ICU) admission were analysed retrospectively to quantify unrecognised lung donors using current criteria, as well as novel time-extended (90 mins-24 hrs post-withdrawal) DCD lung donors., Results: Using standard lung donor eligibility criteria, we identified 473 potential lung donors and a further 122 time-extended DCD potential lung donors among 3,538 patients meeting general eligibility criteria. Detailed review of end-of-life discussions with patient families and the reasons why they were not offered donation revealed several categories of additional lung donors-traditional lung donors missed in current practice (n=2); hepatitis C infected lung donors potentially treatable with direct-acting antivirals (n=14), time-extended DCD lung donors (n=60); donor lungs potentially suitable for transplant with use of ex-vivo lung perfusion (EVLP) (n=7)., Conclusion: While the number of lung donor opportunities missed under existing DonateLife donor identification and management processes was limited, a time-extended DCD lung donation pathway could substantially expand the lung donor pool. The use of hepatitis C infected donors, and the possibility of EVLP to solve donor graft assessment or logistic issues, could also provide small additional lung donor opportunities., (Copyright © 2021 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.)

Recent studies have established that memory B cells, largely thought to be circulatory in the blood, can take up long-term residency in inflamed tissues, analogous to widely described tissue-resident T cells. The dynamics of recruitment and retention of memory B cells to tissues and their immunological purpose remains unclear. Here, we characterized tissue-resident memory B cells (B RM ) that are stably maintained in the lungs of mice after pulmonary influenza infection. Influenza-specific B RM were localized within inducible bronchus-associated lymphoid tissues (iBALTs) and displayed transcriptional signatures distinct from classical memory B cells in the blood or spleen while showing partial overlap with memory B cells in lung-draining lymph nodes. We identified lung-resident markers, including elevated expression of CXCR3, CCR6, and CD69, on hemagglutinin (HA)- and nucleoprotein (NP)-specific lung B RM . We found that CCR6 facilitates increased recruitment and/or retention of B RM in lungs and differentiation into antibody-secreting cells upon recall. Although expression of CXCR3 and CCR6 was comparable in total and influenza-specific memory B cells isolated across tissues of human donors, CD69 expression was higher in memory B cells from lung and draining lymph nodes of human organ donors relative to splenic and PBMC-derived populations, indicating that mechanisms underpinning B RM localization may be evolutionarily conserved. Last, we demonstrate that human memory B cells in lungs are transcriptionally distinct to populations in lung-draining lymph nodes or PBMCs. These data suggest that B RM may constitute a discrete component of B cell immunity, positioned at the lung mucosa for rapid humoral response against respiratory viral infections.

The spleen is a compartmentalized organ that serves as a blood filter and safeguard of systemic immune surveillance. Labyrinthine networks of fibroblastic stromal cells construct complex niches within the white pulp and red pulp that are important for tissue homeostasis and immune activation. However, the identity and roles of the global splenic fibroblastic stromal cells in homeostasis and immune responses are poorly defined. Here, we performed a cellular and molecular dissection of the splenic reticular stromal cell landscape. We found that white pulp fibroblastic reticular cells (FRCs) responded robustly during acute viral infection, but this program of gene regulation was suppressed during persistent viral infection. Single-cell transcriptomic analyses in mice revealed diverse fibroblast cell niches and unexpected heterogeneity among podoplanin-expressing cells that include glial, mesothelial, and adventitial cells in addition to FRCs. We found analogous fibroblastic stromal cell diversity in the human spleen. In addition, we identify the transcription factor SpiB as a critical regulator required to support white pulp FRC differentiation, homeostatic chemokine expression, and antiviral T cell responses. Together, our study provides a comprehensive map of fibroblastic stromal cell types in the spleen and defines roles for red and white pulp fibroblasts for splenic function and orchestration of immune responses.

Increased viral risk donors (IVRDs) with increased risk behaviors for blood-borne virus infection and negative nucleic acid testing have a low absolute risk of "window period" infection. Utilization and allocation of IVRD organs differ between jurisdictions., Methods: We examined the characteristics and utilization of deceased donor IVRD kidneys and recipient outcomes within a 2-y period (July 31, 2018-July 31, 2020) postimplementation of a new opt-in allocation pathway for preconsented recipients in Victoria, Australia., Results: Fifty-six kidneys from 31 IVRDs were utilized, comprising 13% of donors. Preconsent rate to accept IVRD kidneys increased to 41% of the waitlist in the 2 y postimplementation, and IVRDs having no kidneys utilized reduced to 0%. Compared with non-IVRD kidneys, kidney offer declines >10 per donor were less likely from IVRDs (3% vs 19%; P < 0.05). IVRDs were younger (median age 36 [IQR 30-44] vs 51 [35-60] y; P < 0.0001), with lower kidney donor profile index (25% [13-40%] vs 57% [29-75%]; P < 0.0001), and less hypertension (0% vs 22%; P < 0.01). Estimated glomerular filtration rate 3 mo post-transplant was superior ( P < 0.01). Injecting drug use (61%) was the most common increased risk behavior. 29% of IVRDs were hepatitis C antibody positive but nucleic acid testing negative. No active infection was detected in any recipient post-transplant., Conclusions: The described opt-in system permits efficient allocation and utilization of kidneys from IVRDs, with superior quality and graft function. Education is crucial to facilitate informed consent and equity of access to this donor pool., Competing Interests: The authors declare no funding or conflicts of interest., (Copyright © 2021 The Author(s). Transplantation Direct. Published by Wolters Kluwer Health, Inc.)