Introduction Sustaining evidence-based care is challenging in all clinical settings. Acute care settings have a unique set of contextual factors that may impact sustainability (eg, fast-paced, regular staff turnover). Much of the previous research explores sustainability across undifferentiated healthcare settings making it difficult to determine factors that influence sustainability in acute care settings. The aim of this review is to identify facilitators and barriers that influence the delivery of sustained healthcare interventions (eg, integration of clinical guidelines) within adult and paediatric hospital-based acute care settings.Methods and analysis A mixed methods systematic review updating Cowie et al’s (which included studies from 2008 to 2017) previously published systematic review will be conducted. The following databases will be searched: Medline, Embase, Cochrane Database of Systematic Reviews, CINAHL and Allied and Complementary Medicine (AMED), from November 2017 to the present for studies published in English. Relevant reference lists of included studies will be manually searched. Empirical quantitative and qualitative studies that report the sustainability of an intervention or programme in acute care settings using a theoretical framework(s), model(s) or theory(ies) to explore facilitators and barriers, will be included. Studies will be exported into Covidence (Melbourne) and pairs of reviewers will independently screen abstracts and full-text studies. The discussion will be used to resolve any disagreements and a third coauthor enlisted should a consensus not be reached. Two independent coauthors will extract key study characteristics and assess each study’s quality. Data will be extracted using Covidence (Melbourne). Evidence tables will be used to present descriptive data. Facilitators and barriers will be mapped to the Consolidated Framework for Sustainability Constructs in Healthcare and a narrative approach will be used to present key findings.Ethics and dissemination No primary data will be collected so formal ethical approval is not required. Findings will be disseminated through peer-reviewed publications, presented at international conferences and on social media.PROSPERO registration number PROSPERO CRD42024547535.

The zebrafish (Danio rerio) is widely used in vertebrate research, but its reference genome assembly has contained extensively unresolved regions across both euchromatic and heterochromatic compartments. The previous reference genome assembly, GRCz11, consisted of 19,725 contigs assembled into 1,917 scaffolds. Recent advances in both long-read sequencing technologies and genome assembly algorithms have made "complete" genome assemblies possible for the first time. We used homozygous fish from two lab strains, "Tübingen" and "AB," for de novo genome assemblies. The new assemblies incorporated 7% more genomic sequence than GRCz11 and an additional 130 million bases of previously unassembled sequence. RefSeq annotation incorporating newly generated Iso-Seq cDNA sequences have added notable increases in mRNAs (68%), lncRNAs (47%), and misc_RNAs (1099%). Two assemblies have been elevated to reference genome status (GRCz12tu and GRCz12ab). We generated an additional 40 draft haplotypes to create a zebrafish pangenome resource and demonstrate its utility for variant analysis.

OBJECTIVES:Research in critically ill children poses challenges in acquiring prospective informed consent. International ethical guidelines generally have provisions to perform research without prior consent (RWPC) in circumstances where consent is not feasible, but there is a paucity of data regarding the community acceptance of this process. The objectives of the current study were to explore the attitudes and experiences of parents of children enrolled into trials to determine understanding and acceptability of RWPC to parents of children involved. DESIGN:Qualitative study of semi-structured telephone interviews in 2017 exploring themes of medical research, trial participation in RWPC. Interview transcripts underwent inductive thematic analysis with intercoder agreement, using Nvivo 14 software. SETTING:Two clinical interventional trials in Australia conducted in critically ill children without prospective consent. SUBJECTS:Parents of children enrolled in critical care research. INTERVENTIONS:None. MEASUREMENTS AND MAIN RESULTS:A total of 49 interviews were conducted and analyzed. Parents of participants were supportive of processes used in the trials and RWPC. Paperwork was often not thought to contribute to improved understanding, with verbal information more valued. There was no consensus on the optimal approach of RWPC in situations when clinical outcome was poor. CONCLUSIONS:Our study in 2017 shows that parent/carer supported RWPC in two pediatric trials involving critically ill children. Parents were satisfied with existing approval methods and safeguards. Parents valued brief verbal information at the time of randomization. These historical findings support the feasibility of conducting research on time-sensitive interventions in emergency settings with RWPC, aligning with community expectations.

BACKGROUND:Bronchiolitis is the most common reason for hospital admission in infants in Australia and Aotearoa New Zealand (AoNZ), with care historically affected by practice variation, including use of ineffective therapies. The Paediatric Research in Emergency Departments International Collaborative (PREDICT) developed the first Australasian (Australia, AoNZ) bronchiolitis guideline in 2016, providing evidence-based guidance on the management of infants (< 12 months of age), presenting or admitted to hospital with bronchiolitis. In 2022, PREDICT initiated a guideline update to include new evidence and expand the scope to include intensive care (up to intubation), management of SARS-CoV-2 co-infection, and respiratory syncytial virus prevention. AIM:This article outlines the methodology used in the guideline update, following AGREE and CheckUp reporting standards. METHODS:A Guideline Advisory Group and Guideline Development Committee, consisting of 29 clinical and methodological experts from Australasia, developed the guideline with consumer input. Forty-one scoping questions on 25 topics were investigated. Systematic searches were performed by a subject librarian across five electronic databases (last search 24/01/24). Screening of 13,932 new articles occurred independently, in duplicate in two stages. The results of 431 articles were synthesized narratively and quantitatively where appropriate, per topic. Risk of bias was evaluated using appropriate tools. GRADE methodology was used to assess evidence quality and develop the recommendations, which were finalised through consensus voting across three guideline development meetings. RESULTS:The update produced 41 recommendations (33 evidence-based, 8 consensus-based; including 11 new and 7 with key revisions), covering bronchiolitis investigations, management and RSV prevention. Interest-holder groups consulted on the recommendations. CONCLUSION:The Australasian Bronchiolitis Guideline was updated and expanded according to AGREE and CheckUp reporting standards.

BackgroundSalmonella enterica encompasses over 2,600 serovars, including several commonly associated with severe infection in humans. Salmonella is a major cause of sepsis in Africa; however, diagnosis requires clinical microbiology facilities. Environmental surveillance has the potential to play a role in Salmonella surveillance.MethodsWe undertook water-based environmental surveillance in Blantyre, Malawi, from 2018-2020, taking samples from rivers (87.9%), a sewage plant (8.85%) and other water sources (3.24%), isolating and storing 1,042 non-typhoidal Salmonella (NTS) isolates in this period. Of these, 341 NTS isolates were whole genome sequenced, genome quality was checked, duplicate genomes from any given sample were removed and core genome phylogeny was reconstructed. AMRFinder, PathogenWatch and SISTR were used to further investigate serovar, sequence type and antimicrobial resistance determinants.ResultsAfter quality checks, and removal of duplicate genomes, 270 NTS genomes remained for further analysis. Multiple Salmonella serovars associated with human infection were detected, of which S. Typhimurium (55/270 isolates) was the most common, including 44 of Sequence Type (ST) 313, a serovar commonly associated with severe invasive disease (iNTS). Six lineage 2 ST313 genomes possessed AMR genes predicting multidrug resistance (MDR), while 29 lineage 3 isolates contained no AMR predictive genes. PCR based detection of staG has been proposed as a diagnostic marker of S. Typhi; however, all eight genomes that contained staG identified as Salmonella enterica serovar Orion, raising concerns about the specificity of this marker as a monoplex for environmental surveillance of S. Typhi.DiscussionThe study identified diverse Salmonella serovars in the environment, including those reported to cause invasive disease, emphasizing the complex but potentially valuable contribution of implementing environmental surveillance for Salmonella in high burden areas lacking diagnostic microbiology capacity.

The Myc family of proto-oncogenes is a key node for the signal transduction of external pro-proliferative signals to the cellular processes required for development, tissue homoeostasis maintenance, and regeneration across evolution. The tight regulation of Myc synthesis and activity is essential for restricting its oncogenic potential. In this review, we highlight the central role that Myc plays in regeneration across the animal kingdom (from Cnidaria to echinoderms to Chordata) and how Myc could be employed to unlock the regenerative potential of non-regenerative tissues in humans for therapeutic purposes. Mastering the fine balance of harnessing the ability of Myc to promote transcription without triggering oncogenesis may open the door to many exciting opportunities for therapeutic development across a wide array of diseases.

Abstract Next-generation sequencing (NGS) assays play a pivotal role in illuminating the genomic landscape of cancer by providing insights into gene regulation and biomarker detection for the purpose of guiding therapeutic decisions to advance personalized medicine. We validated the Aventa FusionPlus Test, a Laboratory-Developed Test (LDT) that integrates HiC technology to enhance detection of actionable gene fusions and rearrangements in solid tumors, including those that are missed by current standard of care tests. This is a DNA-based test that is robust to DNA degradation in FFPE specimens, in contrast with RNA-seq and long-read technologies. The test utilizes the Element Biosciences AVITI sequencing platform to achieve high quality sequencing data at low cost per sample. The Aventa FusionPlus test enables gene-level detection of structural variants near or within 361 medically actionable or diagnostically relevant cancer genes. The 3D structure and long-range linkages captured by the test amplify the signal counts for each rearrangement. The test integrates the Arima-HiC+ FFPE sample prep and the Arima Library Prep Kit workflow. After dewaxing and rehydrating the FFPE tissue, the chromatinized DNA is fragmented and the fragmented ends are filled in with a biotinylated nucleotide. Next, spatially proximal fragmented ends of DNA are ligated, capturing the 3D structure of the genome. The proximally-ligated DNA is then purified and further fragmented, and the biotinylated ligation fragments are enriched. DNA libraries are prepared from these enriched fragments and sequenced in “paired-end” mode. Genes involved in genomic rearrangements were detected using the Arima-SV pipeline along with manual curation. The test achieved robust detection of structural variants, with accuracy of 98.8% relative to reference methods. FFPE tumor specimens from 10 different tissue types and a wide range of tumor content (20%-100%) were included. No correlation between tumor cellularity and sensitivity was observed, suggesting that samples with as low as 20% tumor cellularity can be tested. When comparing to RNA-based and other targeted reference methods, we found additional fusions nearby oncogenes missed by these reference methods. As an example, in a breast cancer case, a fusion of genomic regions neighboring BRAF and MYC oncogenes on chromosomes 7 and 8 respectively, was missed by the reference method but was successfully detected by the Aventa FusionPlus test. The Aventa FusionPlus test is a highly sensitive, specific, and accurate method for comprehensive cancer genomic profiling. The enhanced understanding of gene fusions and rearrangements positions the test as a valuable tool for clinical decision-making in oncology. Citation Format: Shadi Melnyk, Jon Belton, Sofia Nomikou, Katelyn Powell, Daniel Heiney, Roy Khalife, Damien Jones, Anthony Schmitt, Catherine Wilson, Melissa Won, Anthony Magliocco, Chris Roberts. Validation of Aventa FusionPlus: An LDT NGS assay for comprehensive cancer genomic profiling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 325.

Phenotypic variation among individuals plays a key role in evolution, since variation provides the material on which natural selection can act. One important link between genetic and phenotypic variation is gene expression. As for other phenotypes, the range of accessible expression variation is limited and biased by different evolutionary and developmental constraints. Gene expression variability broadly refers to the tendency of a gene to vary in expression (i.e., between individuals or cells) due to stochastic fluctuations or differences in genetic, epigenetic, or environmental factors, separately from the differences between e.g. organs. Variability due to biomolecular stochasticity (transcriptional 'noise') and cell-to-cell heterogeneity has been well-studied in isogenic populations of unicellular organisms such as bacteria and yeasts. However, for more complex organisms with multiple cells, tissues, and organs sharing the same genetic background, the interplay between inter-individual expression variability, gene and organ function, and gene regulation remains an open question. In this study, we used highly multiplexed 3'-end Bulk RNA Barcoding and sequencing (BRB-seq) to generate transcriptome profiles spanning at least nine organs in outbred individuals of three ray-finned fish species: zebrafish, Northern pike, and spotted gar. For each condition, we measured expression variation per gene independent of mean expression level. We observed that lowly variable genes are enriched in cellular housekeeping functions whereas highly variable genes are enriched in stimulus-response functions. Furthermore, genes with highly variable expression between individuals evolve under weaker purifying selection at the coding sequence level, indicating that intra-species gene expression variability predicts inter-species protein sequence divergence. Genes that are broadly expressed across organs tend to be both highly expressed and lowly variable between individuals, whereas organ-biased genes are typically highly variable within their top organ of expression. For genes with organ-biased expression profiles, we inferred differences in selective pressure on gene regulation depending on their top organ. We found that genes with peak expression in the brain have low inter-individual expression variability across non-nervous organs, suggesting stabilizing selection on regulatory evolution of brain-biased genes. Conversely, liver-biased genes have highly variable expression across organs, implying weaker regulatory constraints. These patterns show that gene regulatory mechanisms evolved differently based on constraints on the primary organ. ### Competing Interest Statement The authors have declared no competing interest.

Ugur et al. characterize the bridge-like lipid transfer protein VPS13B and report its localization between Golgi cisternae and its impact on Golgi complex reformation after its BFA-induced dispersion. They also provide evidence for its functional partnership with FAM177A1, a newly identified Golgi complex protein. Mutations in VPS13B, a member of a protein family implicated in bulk lipid transport between adjacent membranes, cause Cohen syndrome. VPS13B is known to be concentrated in the Golgi complex, but its precise location within this organelle and thus the site(s) where it achieves lipid transport remains unclear. Here, we show that VPS13B is localized at the interface between proximal and distal Golgi subcompartments and that Golgi complex reformation after Brefeldin A (BFA)-induced disruption is delayed in VPS13B KO cells. This delay is phenocopied by the loss of FAM177A1, a Golgi complex protein of unknown function reported to be a VPS13B interactor and whose mutations also result in a developmental disorder. In zebrafish, the vps13b ortholog, not previously annotated in this organism, genetically interacts with fam177a1. Collectively, these findings raise the possibility that bulk lipid transport by VPS13B may play a role in the dynamics of Golgi membranes and that VPS13B may be assisted in this function by FAM177A1.

The genetics of sex determination varies across taxa, sometimes even within a species. Major domesticated strains of zebrafish (Danio rerio), including AB and TU, lack a strong genetic sex determining locus, but strains more recently derived from nature, like Nadia (NA), possess a ZZ male/ZW female chromosomal sex-determination system. AB fish pass through a juvenile ovary stage, forming oocytes that survive in fish that become females but die in fish that become males. To understand mechanisms of gonad development in NA zebrafish, we studied histology and single cell transcriptomics in developing ZZ and ZW fish. ZW fish developed oocytes by 22 days post-fertilization (dpf) but ZZ fish directly formed testes, avoiding a juvenile ovary phase. Gonads of some ZW and WW fish, however, developed oocytes that died as the gonad became a testis, mimicking AB fish, suggesting that the gynogenetically derived AB strain is chromosomally WW. Single-cell RNA-seq of 19dpf gonads showed similar cell types in ZZ and ZW fish, including germ cells, precursors of gonadal support cells, steroidogenic cells, interstitial/stromal cells, and immune cells, consistent with a bipotential juvenile gonad. In contrast, scRNA-seq of 30dpf gonads revealed that cells in ZZ gonads had transcriptomes characteristic of testicular Sertoli, Leydig, and germ cells while ZW gonads had granulosa cells, theca cells, and developing oocytes. Hematopoietic and vascular cells were similar in both sex genotypes. These results show that juvenile NA zebrafish initially develop a bipotential gonad; that a factor on the NA W chromosome, or fewer than two Z chromosomes, is essential to initiate oocyte development; and without the W factor, or with two Z doses, NA gonads develop directly into testes without passing through the juvenile ovary stage. Sex determination in AB and TU strains mimics NA ZW and WW zebrafish, suggesting loss of the Z chromosome during domestication. Genetic analysis of the NA strain will facilitate our understanding of the evolution of sex determination mechanisms.

Objective Visceral pain is a leading cause of morbidity in inflammatory bowel disease (IBD), contributing significantly to reduced quality of life. Currently available analgesics often lack efficacy or have intolerable side-effects, driving the need for a more complete understanding of the mechanisms causing pain. Methods Whole transcriptome gene expression analysis was performed by bulk RNA sequencing of colonic biopsies from patients with ulcerative colitis (UC) and Crohn’s disease (CD) reporting abdominal pain and compared with non-inflamed control biopsies. Putative pro-nociceptive mediators were identified based on pathway analysis of differentially expressed genes in IBD tissue and single cell gene expression in colonic neurons. Pro-nociceptive activity of identified mediators was assessed in assays of sensory neuron and colonic afferent activity. Results RNA sequencing analysis highlighted a 7.6-fold increase in the expression of angiotensinogen transcripts, Agt, the precursor to angiotensin II (Ang II), in samples from UC patients (p = 3.2×10 -8 ). Consistent with the marked expression of the angiotensin AT 1 receptor in colonic neurons, Ang II elicited an increase in intracellular Ca 2+ in capsaicin-sensitive, voltage gated sodium channel subtype Na V 1.8-positive sensory neurons. Ang II also evoked action potential discharge in high-threshold colonic nociceptors. These effects were inhibited by the AT 1 receptor antagonist valsartan. Conclusion Findings from our study identify AT 1 receptor-mediated colonic nociceptor activation as a novel pathway of visceral nociception in IBD patients with UC. This work highlights the potential utility of angiotensin receptor blockers, such as valsartan, as treatments for pain in IBD.

ABSTRACT Wild zebrafish ( Danio rerio ) have a ZZ/ZW chromosomal sex determination system with the major sex locus on the right arm of chromosome-4 (Chr4R) near the largest heterochromatic block in the genome, suggesting the hypothesis that the Chr4R transcriptome might be different from the rest of the genome. We conducted an RNA-seq analysis of adult ZW ovaries and ZZ testes and identified four regions of Chr4 with different gene expression profiles. Unique in the genome, protein-coding genes in a 41.7 Mb section (Region-2) were expressed in testis but silent in ovary. The AB lab strain, which lacks sex chromosomes, verified this result, showing that testis-biased gene expression in Region-2 depends on gonad biology, not on sex-determining mechanism. RNA-seq analyses in female and male brain and liver validated few transcripts from Region-2 in somatic cells, but without sex-specificity. Region-2 corresponds to the heterochromatic portion of Chr4R and its content of genes and repetitive elements distinguishes it from the rest of the genome. In Region-2, protein-coding genes lack human orthologs; it has zinc finger genes expressed early in zygotic genome activation; it has maternal 5S rRNA genes, maternal spliceosome genes, a concentration of tRNA genes, and an distinct set of repetitive elements. The colocalization of 1) genes silenced in ovaries but not in testes that are 2) expressed in embryos briefly at the onset of zygotic genome activation; 3) maternal-specific genes for translation machinery; 4) maternal-specific spliceosome components; and 4) adjacent genes encoding miR-430, which mediates maternal transcript degradation, suggest that this is a Maternal-to-Zygotic-Transition Gene Regulatory Block. ARTICLE SUMMARY The wild zebrafish sex chromosome has a region, unique in the genome, that contains protein-coding genes silenced in ovaries but expressed in testes and transiently in the embryo as it begins to express its own genes. This region also contains maternal-specific genes encoding the protein-synthesis machinery used specifically by developing embryos, and molecules that target for degradation messenger RNAs that the mother stored in her eggs. This region defines a distinct maternal-to-zygotic-transition gene block.

Persistent organic pollutants (POPs) are lipophilic compounds that bioaccumulate in animals and biomagnify within food webs. Many POPs are endocrine disrupting compounds that impact vertebrate development. POPs accumulate in the Arctic via global distillation and thereby impact high trophic level vertebrates as well as people who live a subsistence lifestyle. The Arctic also contains thousands of point sources of pollution, such as formerly used defense (FUD) sites. Sivuqaq (St. Lawrence Island), Alaska was used by the U.S. military during the Cold War and FUD sites on the island remain point sources of POP contamination. We examined the effects of POP exposure on ninespine stickleback (Pungitius pungitius) collected from Troutman Lake in the village of Gambell as a model for human exposure and disease. During the Cold War, Troutman Lake was used as a dump site by the U.S. military. We found that PCB concentrations in stickleback exceeded the U.S. Environmental Protection Agency's guideline for unlimited consumption despite these fish being low trophic level organisms. We examined effects at three levels of biological organization: gene expression, endocrinology, and histomorphology. We found that ninespine stickleback from Troutman Lake exhibited suppressed gonadal development compared to threespine stickleback (Gasterosteus aculeatus) studied elsewhere. Troutman Lake stickleback also displayed two distinct hepatic phenotypes, one with lipid accumulation and one with glycogen-type vacuolation. We compared the transcriptomic profiles of these liver phenotypes using RNA sequencing and found significant upregulation of genes involved in ribosomal and metabolic pathways in the lipid accumulation group. Additionally, stickleback displaying liver lipid accumulation had significantly fewer thyroid follicles than the vacuolated phenotype. Our study and previous work highlight health concerns for people and wildlife due to pollution hotspots in the Arctic, and the need for health-protective remediation.

Alaska contains over 600 formerly used defense (FUD) sites, many of which serve as point sources of pollution. These sites are often co-located with rural communities that depend upon traditional subsistence foods, especially lipid-rich animals that bioaccumulate and biomagnify persistent organic pollutants (POPs). Many POPs are carcinogenic and endocrine-disrupting compounds that are associated with adverse health outcomes. Therefore, elevated exposure to POPs from point sources of pollution may contribute to disproportionate incidence of disease in arctic communities. We investigated PCB concentrations and the health implications of POP exposure in sentinel fishes collected near the Northeast Cape FUD site on Sivuqaq (St. Lawrence Island), Alaska. Sivuqaq residents are almost exclusively Yupik and rely on subsistence foods. At the request of the Sivuqaq community, we examined differential gene expression and developmental pathologies associated with exposure to POPs originating at the Northeast Cape FUD site. We found significantly higher levels of PCBs in Alaska blackfish (Dallia pectoralis) collected from contaminated sites downstream of the FUD site compared to fish collected from upstream reference sites. We compared transcriptomic profiles and histopathologies of these same blackfish. Blackfish from contaminated sites overexpressed genes involved in ribosomal and FoxO signaling pathways compared to blackfish from reference sites. Contaminated blackfish also had significantly fewer thyroid follicles and smaller pigmented macrophage aggregates. Conversely, we found that ninespine stickleback (Pungitius pungitius) from contaminated sites exhibited thyroid follicle hyperplasia. Despite our previous research reporting transcriptomic and endocrine differences in stickleback from contaminated vs. reference sites, we did not find significant differences in kidney or gonadal histomorphologies. Our results demonstrate that contaminants from the Northeast Cape FUD site are associated with altered gene expression and thyroid development in native fishes. These results are consistent with our prior work demonstrating disruption of the thyroid hormone axis in Sivuqaq residents.

Cardiac injury, such as myocardial infarction (MI), results in permanent loss of cardiomyocytes and in many cases heart failure. Transgenic expression of the pro-proliferative transcription factor Myc and Cyclin T1 can drive substantial adult cardiomyocyte proliferation to replace lost cardiomyocytes. Herein, we show that Myc and Cyclin T1 induced cardiomyocyte proliferation leads to myocardial repair and functional (long-term) recovery post-MI in mice. To provide a more translational approach, we developed modified mRNA (modRNA) encoding Myc-Ccnt1 as a transient and non-integrating strategy for regeneration. One dose of Myc-Ccnt1 modRNA is sufficient to transiently drives cardiomyocyte proliferation in human pluripotent stem cell-derived cardiomyocytes and a mouse MI model, where it leads to better heart function. Using single nuclei sequencing and proteomics, we show this was functionally mediated by transcriptional activation of cell-cycle regulating genes, which ultimately results in mitosis and cytokinesis of cardiomyocytes. Collectively, these findings indicate that Myc-Ccnt1 modRNA has the potential to be an effective regenerative therapeutic.

Clustering of MALDI imaging dataset for a lung section.

OBJECTIVES:To examine the clinical characteristics and short term outcomes for children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections who presented to Australian hospitals during 2020 and 2021.DESIGN, SETTING:Retrospective case review study in nineteen hospitals of the Paediatric Research in Emergency Departments International Collaborative (PREDICT) network from all Australian states and territories, including seven major paediatric tertiary centres and eight Victorian hospitals.PARTICIPANTS:SARS-CoV-2-positive people under 18 years of age who attended emergency departments or were admitted to hospital during 1 February 2020 - 31 December 2021.MAIN OUTCOME MEASURES:Epidemiological and clinical characteristics, by hospital care type (emergency department [ED] or inpatient care).RESULTS:A total of 1193 SARS-CoV-2-positive children and adolescents (527 girls, 44%) attended the participating hospitals (107 in 2020, 1086 in 2021). Their median age was 3.8 years (interquartile range [IQR], 0.8-11.4 years); 63 were Aboriginal or Torres Strait Islander people (5%). Other medical conditions were recorded for 293 children (25%), including asthma (86, 7%) and premature birth (68, 6%). Medical interventions were not required during 795 of 1181 ED presentations (67%); children were discharged directly home in 764 cases (65%) and admitted to hospital in 282 (24%; sixteen to intensive care units). The 384 admissions to hospital (including 102 direct admissions) of 341 children (25 infants under one month of age) included 23 to intensive care (6%); the median length of stay was three days (IQR, 1-9 days). Medical interventions were not required during 261 admissions (68%); 44 children received respiratory support (11%) and 21 COVID-19-specific treatments, including antiviral and biologic agents (5%). Being under three months of age (v one year to less than six years: odds ratio [OR], 2.6; 95% confidence interval [CI], 1.7-4.0) and pre-existing medical conditions (OR, 2.5; 95% CI, 1.9-3.2) were the major predictors of hospital admission. Two children died, including one without a known pre-existing medical condition.CONCLUSION:During 2020 and 2021, most SARS-CoV-2-positive children and adolescents who presented to participating hospitals could be managed as outpatients. Outcomes were generally good, including for those admitted to hospital.

Example chromatograms for eicosanoid analysis by LC-MS/MS.

Staining for proliferation and apoptosis before and after MYC deactivation.