Hyperhydration to Improve Kidney Outcomes in Children with Shiga Toxin-Producing E. coli Infection: A multinational embedded cluster crossover randomized trial (the HIKO STEC trial)

BACKGROUND: Shiga toxin-producing E. coli (STEC) infections affect children and adults worldwide, and treatment remain solely supportive. Up to 15-20% of children infected by high-risk STEC (i.e., E. coli that produce Shiga toxin 2) develop hemolytic anemia, thrombocytopenia, and kidney failure (i.e., hemolytic uremic syndrome (HUS)), over half of whom require acute dialysis and 3% die. Although no therapy is widely accepted as being able to prevent the development of HUS and its complications, several observational studies suggest that intravascular volume expansion (hyperhydration) may prevent end organ damage. A randomized trial is needed to confirm or refute this hypothesis. METHODS: We will conduct a pragmatic, embedded, cluster-randomized, crossover trial in 26 pediatric institutions to determine if hyperhydration, compared to conservative fluid management, improves outcomes in 1040 children with high-risk STEC infections. The primary outcome is major adverse kidney events within 30 days (MAKE30), a composite measure that includes death, initiation of new renal replacement therapy, or persistent kidney dysfunction. Secondary outcomes include life-threatening, extrarenal complications, and development of HUS. Pathway eligible children will be treated per institutional allocation to each pathway. In the hyperhydration pathway, all eligible children are hospitalized and administered 200% maintenance balanced crystalloid fluids up to targets of 10% weight gain and 20% reduction in hematocrit. Sites in the conservative fluid management pathway manage children as in- or outpatients, based on clinician preference, with the pathway focused on close laboratory monitoring, and maintenance of euvolemia. Based on historical data, we estimate that 10% of children in our conservative fluid management pathway will experience the primary outcome. With 26 clusters enrolling a mean of 40 patients each with an intraclass correlation coefficient of 0.11, we will have 90% power to detect a 5% absolute risk reduction. DISCUSSION: HUS is a devastating illness with no treatment options. This pragmatic study will determine if hyperhydration can reduce morbidity associated with HUS in children with high-risk STEC infection. TRIAL REGISTRATION: ClinicalTrials.gov NCT05219110 . Registered on February 1, 2022

Measure what matters: considerations for outcome measurement of care coordination for children with neurodevelopmental disabilities and medical complexity

IntroductionCare Coordination (CC) is a significant intervention to enhance family’s capacity in caring for children with neurodevelopmental disability and medical complexity (NDD-MC). CC assists with integration of medical and behavioral care and services, partnerships with medical and community-based supports, and access to medical, behavioral, and educational supports and services. Although there is some consensus on the principles that characterize optimal CC for children with NDD-MC, challenges remain in measuring and quantifying the impacts of CC related to these principles. Two key challenges include: (1) identification of measures that capture CC impacts from the medical system, care provider, and family perspectives; and (2) recognition of the important community context outside of a hospital or clinical setting.MethodsThis study used a multilevel model variant of the triangulation mixed methods design to assess the impact of a CC project implemented in Alberta, Canada, on family quality of life, resource use, and care integration at the broader environmental and household levels. At the broader environmental level, we used linked administrative data. At the household level we used quantitative pre-post survey datasets, and aggregate findings from qualitative interviews to measure group-level impacts and an embedded multiple-case design to draw comparisons, capture the nuances of children with NDD-MC and their families, and expand on factors driving the high variability in outcome measures. Three theoretical propositions formed the basis of the analytical strategy for our case study evidence to explore factors affecting the high variability in outcome measures.DiscussionThis study expanded on the factors used to measure the outcomes of CC and adds to our understanding of how CC as an intervention impacts resource use, quality of life, and care integration of children with NDD-MC and their families. Given the heterogeneous nature of this population, evaluation studies that account for the variable and multi-level impacts of CC interventions are critical to inform practice, implementation, and policy of CC for children with NDD-MC

Alterations in Retrotransposition, Synaptic Connectivity, and Myelination Implicated by Transcriptomic Changes Following Maternal Immune Activation in Nonhuman Primates

BackgroundMaternal immune activation (MIA) is a proposed risk factor for multiple neuropsychiatric disorders, including schizophrenia. However, the molecular mechanisms through which MIA imparts risk remain poorly understood. A recently developed nonhuman primate model of exposure to the viral mimic poly:ICLC during pregnancy shows abnormal social and repetitive behaviors and elevated striatal dopamine, a molecular hallmark of human psychosis, providing an unprecedented opportunity for studying underlying molecular correlates.MethodsWe performed RNA sequencing across psychiatrically relevant brain regions (prefrontal cortex, anterior cingulate, hippocampus) and primary visual cortex for comparison from 3.5- to 4-year-old male MIA-exposed and control offspring-an age comparable to mid adolescence in humans.ResultsWe identify 266 unique genes differentially expressed in at least one brain region, with the greatest number observed in hippocampus. Co-expression networks identified region-specific alterations in synaptic signaling and oligodendrocytes. Although we observed temporal and regional differences, transcriptomic changes were shared across first- and second-trimester exposures, including for the top differentially expressed genes-PIWIL2 and MGARP. In addition to PIWIL2, several other regulators of retrotransposition and endogenous transposable elements were dysregulated following MIA, potentially connecting MIA to retrotransposition.ConclusionsTogether, these results begin to elucidate the brain-level molecular processes through which MIA may impart risk for psychiatric disease

Inhibition of overactivated p38 MAPK can restore hematopoiesis in myelodysplastic syndrome progenitors

The myelodysplastic syndromes (MDSs) are collections of heterogeneous hematologic diseases characterized by refractory cytopenias as a result of ineffective hematopoiesis. Development of effective treatments has been impeded by limited insights into any unifying pathogenic pathways. We provide evidence that the p38 MAP kinase is constitutively activated or phosphorylated in MDS bone marrows. Such activation is uniformly observed in varied morphologic subtypes of low-risk MDS and correlates with enhanced apoptosis observed in MDS hematopoietic progenitors. Most importantly, pharmacologic inhibition of p38α by a novel small molecule inhibitor, SCIO-469, decreases apoptosis in MDS CD34+ progenitors and leads to dose-dependant increases in erythroid and myeloid colony formation. Down-regulation of the dominant p38α isoform by siRNA also leads to enhancement of hematopoiesis in MDS bone marrow progenitors in vitro. These data implicate p38 MAPK in the pathobiology of ineffective hematopoiesis in lowrisk MDS and provide a strong rationale for clinical investigation of SCIO-469 in MDS

Genetic and cellular evidence of vascular inflammation in neurofibromin-deficient mice and humans

Neurofibromatosis type 1 (NF1) results from mutations in the NF1 tumor suppressor gene, which encodes the protein neurofibromin. NF1 patients display diverse clinical manifestations, including vascular disease, which results from neointima formation and vessel occlusion. However, the pathogenesis of NF1 vascular disease remains unclear. Vessel wall homeostasis is maintained by complex interactions between vascular and bone marrow–derived cells (BMDCs), and neurofibromin regulates the function of each cell type. Therefore, utilizing cre/lox techniques and hematopoietic stem cell transplantation to delete 1 allele of Nf1 in endothelial cells, vascular smooth muscle cells, and BMDCs alone, we determined which cell lineage is critical for neointima formation in vivo in mice. Here we demonstrate that heterozygous inactivation of Nf1 in BMDCs alone was necessary and sufficient for neointima formation after vascular injury and provide evidence of vascular inflammation in Nf1+/– mice. Further, analysis of peripheral blood from NF1 patients without overt vascular disease revealed increased concentrations of inflammatory cells and cytokines previously linked to vascular inflammation and vasoocclusive disease. These data provide genetic and cellular evidence of vascular inflammation in NF1 patients and Nf1+/– mice and provide a framework for understanding the pathogenesis of NF1 vasculopathy and potential therapeutic and diagnostic interventions

Baseline immunoreactivity before pregnancy and poly(I:C) dose combine to dictate susceptibility and resilience of offspring to maternal immune activation

Despite the potential of rodent models of maternal immune activation (MIA) to identify new biomarkers and therapeutic interventions for a range of psychiatric disorders, current approaches using these models ignore two of the most important aspects of this risk factor for human disease: (i) most pregnancies are resilient to maternal viral infection and (ii) susceptible pregnancies can lead to different combinations of phenotypes in offspring. Here, we report two new sources of variability-the baseline immunoreactivity (BIR) of isogenic females prior to pregnancy and differences in immune responses in C57BL/6 dams across vendors-that contribute to resilience and susceptibility to distinct combinations of behavioral and biological outcomes in offspring. Similar to the variable effects of human maternal infection, MIA in mice does not cause disease-related phenotypes in all pregnancies and a combination of poly(I:C) dose and BIR predicts susceptibility and resilience of pregnancies to aberrant repetitive behaviors and alterations in striatal protein levels in offspring. Even more surprising is that the intermediate levels of BIR and poly(I:C) dose are most detrimental to offspring, with higher BIR and poly(I:C) doses conferring resilience to measured phenotypes in offspring. Importantly, we identify the BIR of female mice as a biomarker before pregnancy that predicts which dams will be most at risk as well as biomarkers in the brains of newborn offspring that correlate with changes in repetitive behaviors. Together, our results highlight considerations for optimizing MIA protocols to enhance rigor and reproducibility and reveal new factors that drive susceptibility of some pregnancies and resilience of others to MIA-induced abnormalities in offspring

Sequential perturbations to mouse corticogenesis following in utero maternal immune activation.

In utero exposure to maternal immune activation (MIA) is an environmental risk factor for neurodevelopmental and neuropsychiatric disorders. Animal models provide an opportunity to identify mechanisms driving neuropathology associated with MIA. We performed time-course transcriptional profiling of mouse cortical development following induced MIA via poly(I:C) injection at E12.5. MIA-driven transcriptional changes were validated via protein analysis, and parallel perturbations to cortical neuroanatomy were identified via imaging. MIA-induced acute upregulation of genes associated with hypoxia, immune signaling, and angiogenesis, by 6 hr following exposure. This acute response was followed by changes in proliferation, neuronal and glial specification, and cortical lamination that emerged at E14.5 and peaked at E17.5. Decreased numbers of proliferative cells in germinal zones and alterations in neuronal and glial populations were identified in the MIA-exposed cortex. Overall, paired transcriptomic and neuroanatomical characterization revealed a sequence of perturbations to corticogenesis driven by mid-gestational MIA

Sequential perturbations to mouse corticogenesis following in utero maternal immune activation.

In utero exposure to maternal immune activation (MIA) is an environmental risk factor for neurodevelopmental and neuropsychiatric disorders. Animal models provide an opportunity to identify mechanisms driving neuropathology associated with MIA. We performed time-course transcriptional profiling of mouse cortical development following induced MIA via poly(I:C) injection at E12.5. MIA-driven transcriptional changes were validated via protein analysis, and parallel perturbations to cortical neuroanatomy were identified via imaging. MIA-induced acute upregulation of genes associated with hypoxia, immune signaling, and angiogenesis, by 6 hr following exposure. This acute response was followed by changes in proliferation, neuronal and glial specification, and cortical lamination that emerged at E14.5 and peaked at E17.5. Decreased numbers of proliferative cells in germinal zones and alterations in neuronal and glial populations were identified in the MIA-exposed cortex. Overall, paired transcriptomic and neuroanatomical characterization revealed a sequence of perturbations to corticogenesis driven by mid-gestational MIA