Publications

Background The Resuscitation in Paediatric Septic Shock using Vitamin C and Hydrocortisone (RESPOND) trial is a multicentre randomised controlled trial exploring whether the use of hydrocortisone alone, or in combination with vitamin C, increases time alive and free of vasopressors for critically ill children. Objective To present the prespecified statistical analysis plan (SAP) for the RESPOND trial prior to finalising recruitment and locking the trial dataset. Design, setting, and participants The RESPOND trial is a three-arm, parallel group, open-label, randomised controlled trial, recruiting in paediatric intensive care units in Australia, New Zealand, India, and Brazil. The planned sample size is 384 participants. Main outcome measures The primary outcome is time alive and free of inotropes/vasopressors, censored at 7 days post-randomisation. Secondary outcomes include clinical (e.g. alive and free of multi-organ dysfunction, length of stay), safety, health economics (e.g. incremental costs, quality-adjusted life years), and long-term outcomes (measured at 6 months post-randomisation; e.g. health-related quality of life). Results and conclusions The SAP was designed by the Chief Investigators and approved by the RESPOND Steering Committee. Statistical analyses are summarised. The primary outcome will be analysed using quantile regression adjusted for stratification variables. Appropriate statistical comparisons between groups were planned and described in a way that is transparent, available to the public, verifiable, and predetermined before completion of data collection. The trial statistician, RESPOND Steering Committee members, and SAP authors remain blind to treatment allocation throughout the study. Data Safety and Monitoring Board members were provided with safety data with masked group identifiers during interim analyses. The RESPOND trial commenced recruitment in December, 2021, and aims to complete recruitment by mid-2026. Trial registration ACTRN12621000247875.

Aging is asynchronous across cells and organs. Here we tested whether plasma proteomics can be used to analyze cell type-specific aging. From analyses of over 7,000 plasma proteins measured in 60,542 individuals, we developed machine learning models to estimate the biological age of over 40 cell types spanning neuronal, immune, glial, endocrine, epithelial and musculoskeletal origins. We observed that 20–25% of individuals exhibited accelerated aging in a single cell type and 1–3% in 10 or more cell types. Cellular aging signatures were associated with disease status and predicted incident disease and mortality over 15 years of follow-up. Individuals with the APOE4 genotype showed older astrocytes but younger macrophages compared to APOE3 carriers, whereas the APOE2 genotype had inverse associations. Moreover, extreme astrocyte aging tripled the risk of incident Alzheimer’s Disease in individuals with two APOE4 alleles, while youthful astrocytes reduced risk. Individuals with extremely aged compared to youthful skeletal myocytes exhibited a 12.7-fold higher risk of developing amyotrophic lateral sclerosis. In individuals who smoked, extreme respiratory epithelial cell aging was associated with a 58% higher lung cancer risk compared to smoking alone. Specific cellular vulnerabilities and cumulative cellular aging burden influenced survival, with youthful immune and neuronal cell types conferring protective effects. Finally, we developed a polycellular aging risk score that stratified mortality risk across cohorts and proteomics platforms. These findings establish a framework for quantifying human physiology at cellular resolution, revealing heterogeneous aging trajectories and their impact on disease susceptibility and resilience.

An in-operando electro-intercalation method for the on-chip synthesis of alkali-metal-intercalated materials and their Raman spectroscopic and transport characterization in ultrahigh vacuum (UHV) is developed. We apply this method to synthesize fulleride superconductors via Rb+ intercalation into a C60 film. During the intercalation, we monitor the stoichiometry via UHV-Raman spectroscopy and probe superconductivity via transport measurements. An increase of the superconducting transition temperature from 7.0 K to 14.5 K is observed when the stoichiometry is tuned from Rb2.7C60 to Rb3C60. In our experiment, an ionic Rb+ flux into the host material is induced by an applied electronic current via a Butler–Volmer-type mechanism. Electro-intercalation captivates through improved stoichiometric precision, the ability to smoothly vary stoichiometry via duration of current application, and the absence of a lower limit of the volume of the host material. It represents a powerful concept for the on-chip synthesis of intercalated materials, battery research, and beyond.

Background: Critically ill children receiving continuous renal replacement therapy may experience sub-therapeutic concentrations for antimicrobials leading to treatment failure and antimicrobial resistant pathogens. The objective of this study was to determine whether antimicrobial concentrations are reduced by a paediatric continuous renal replacement therapy (CRRT). Method: An ex vivo closed continuous veno–venous haemodiafiltration was simulated for a 3 kg infant to assess antimicrobial clearance across three ultrafiltration rates (zero, low and high flux). Slow continuous ultrafiltration was used to assess antimicrobial adsorption and recovery over 240 minutes. Controls were included to account for spontaneous drug degradation. This study was conducted in a university research laboratory with no participants. Antimicrobial concentrations were measured using a validated HPLC-MS/MS method. Results: The antimicrobial filter clearance during high-flux filtration was significantly increased for fluconazole, piperacillin, tazobactam, vancomycin and voriconazole (P < 0.05). The antimicrobial recovery [mean (%)] at 240 minutes in the CRRT model was significantly different from baseline (time zero) for ampicillin 49%, fluconazole 76%, gentamicin (0%) meropenem 51%, piperacillin 54%, vancomycin 31% and voriconazole 47% (P < 0.05). A significant relationship was demonstrated between antimicrobial recovery and molecular charge (R2 = 0.58 P 70% of the study antimicrobials in the ex vivo paediatric CRRT model, as a result of an increase in filter clearance during high-flux filtration or from drug-circuit adsorption. These findings suggests that antimicrobial dosing in critically ill children receiving CRRT requires assessment to determine whether antimicrobial concentrations are therapeutic.

In the 1970s, physicist Richard Feynman turned lunch with a friend into a math problem—how to optimize dish selection over multiple meals—but his handwritten notes remained a mystery for decades. Here we present the fully deciphered problem and solution, prove its optimality, generalize it to related problems, and compare the results to human behavior. The optimal policy specifies decreasing thresholds for switching from exploring new dishes to exploiting the best, with thresholds varying based on the distribution of the quality of dishes. We connect these results to the existing psychological literature on optimal stopping problems, which has explored close variants on Feynman’s problem, and use our generalization of the solution to explore how the underlying distribution of the quality of the options influences people’s choices. A preregistered experiment with 2,520 participants shows that people adopt thresholds that decrease linearly with the proportion of trials remaining, consistent with the observation of linear thresholds in other optimal stopping problems. However, we show that people tend to explore more than predicted by linear thresholds, and that different distributions of quality result in thresholds with the same slope but different intercepts. These results indicate that people adapt linear thresholds used in optimal stopping tasks in a way that is sensitive to the underlying distribution—a simple strategy that we show is nearly as effective as Feynman’s solution.

During the progression of amyotrophic lateral sclerosis (ALS), only specific motor neurons (MNs) preferentially deteriorate, while others are spared until the disease reaches its end stage. Resilient MNs possess several protective factors, yet the precise molecular mechanism(s) underlying selective neuronal vulnerability remains poorly understood. Vesicle-associated membrane protein (VAMP)-binding protein B (VAPB) is an endoplasmic reticulum (ER) protein involved in protein quality control (PQC) mechanisms, including unfolded protein response (UPR) as well as autophagy. A dominantly inherited P56S mutation in the VAPB gene has been linked to ALS8, atypical ALS, and late-onset spinal muscular atrophy (SMA). The P56S VAPB mutation causes ER-associated inclusions, disorganization, and ER stress, contributing to MN degeneration through toxic gain and loss of function. Over-expression of VAPB protein confers neuroprotection in a mouse model of ALS, and increased levels of neuronal VAPB inversely correlate with the absence of pathological aggregates. We hypothesize that VAPB is crucial for motor neuron survival by promoting autophagic degradation of ALS-associated aggregates, while lack of VAPB confers neuronal vulnerability. We analyzed the brain and spinal cord from sporadic (s) and familial (f) ALS patients, comparing patterns of VAPB immunoreactivity using immunohistochemistry, complemented by Western and dot blot analysis. Pathophysiological insights from these studies were further explored using cell culture models, including MNs derived from induced pluripotent stem cells (iPSCs). Consistent with our hypothesis we observed that MNs/neurons resistant to ALS exhibited elevated levels of VAPB and were devoid of pathogenic aggregates. Similarly, ALS-resistant oculomotor neurons showed increased VAPB immunoreactivity compared to normal controls. VAPB was often found to be sequestered within toxic aggregates alongside autophagy-related proteins in the lumbar spinal cord MNs. Notably, a compensatory increase in VAPB immunoreactivity was observed at the C-bouton synapse, suggesting a potential alternative mechanism of neuroprotection. Supporting these findings, in vitro experiments indicated that VAPB overexpression promoted autophagy and assisted in clearing ALS-associated RNA-binding protein aggregates. In summary, VAPB promotes selective neuronal survival by facilitating the autophagic clearance of toxic aggregates. Abnormal VAPB accumulations likely disrupt these neuroprotective processes.

Astrocytes modulate brain processes such as neurotransmitter signaling, ion homeostasis, vascular tone, metabolism and synaptic transmission, and serve a critical role in complex brain functions. However, it remains unclear on which spatial scales these functions are organized in astrocytes and their networks: for instance, whether astrocytic interactions with neurons are organized into units at the level of individual perisynaptic processes and synapses, astrocytic domains covering synapse populations, or astrocytic networks controlling local neuronal circuits. Here we analyze astrocytic morphological features and molecular heterogeneity to define the multiple spatial scales on which astrocytes operate. We further discuss evidence regarding their intracellular and intercellular signaling, their role in neurotransmitter homeostasis and their neurotransmitter-mediated dialog with neurons, supporting the existence of astrocytic functional units with distinct spatial scales. We propose that astrocytes constitute a multilayered system of functional units that operate across multiple spatial scales, thereby increasing the degrees of freedom in brain information processing.

Many diseases, including obesity, have systemic effects that perturb multiple organ systems throughout the body1,2. However, tools for comprehensive, high-resolution analysis of disease-associated changes at the whole-body scale have been lacking. Here we developed MouseMapper, a suite of foundation-model-based deep-learning algorithms enabling multi-system analysis of disease across the entire mouse body. MouseMapper enables whole-body quantitative analysis of nerves and immune cells, resolving fine axonal branches and immune-cell clusters while automatically segmenting 31 organs and tissues. We used MouseMapper to study diet-induced obesity, and identified structural alterations of the infraorbital branch of the trigeminal ganglia. This structural impairment in infraorbital nerves was associated with functional sensory deficits in whisker sensing. Furthermore, we identified proteomic changes in the trigeminal ganglion affecting axon remodelling and complement pathways both in mice and humans. MouseMapper also generated detailed three-dimensional inflammation maps by characterizing immune cell cluster compositions across tissues. The MouseMapper framework demonstrates robust generalizability across different imaging resolutions and datasets. Our study provides a powerful, scalable approach for identifying and quantifying systemic pathologies, bridging molecular insights from animal models to human conditions.