Molecular Basis of Chemotactile Sensation in Octopus.

Animals display wide-ranging evolutionary adaptations based on their ecological niche. Octopuses explore the seafloor with their flexible arms using a specialized "taste by touch" system to locally sense and respond to prey-derived chemicals and movement. How the peripherally distributed octopus nervous system mediates relatively autonomous arm behavior is unknown. Here, we report that octopus arms use a family of cephalopod-specific chemotactile receptors (CRs) to detect poorly soluble natural products, thereby defining a form of contact-dependent, aquatic chemosensation. CRs form discrete ion channel complexes that mediate the detection of diverse stimuli and transduction of specific ionic signals. Furthermore, distinct chemo- and mechanosensory cells exhibit specific receptor expression and electrical activities to support peripheral information coding and complex chemotactile behaviors. These findings demonstrate that the peripherally distributed octopus nervous system is a key site for signal processing and highlight how molecular and anatomical features synergistically evolve to suit an animal's environmental context.

ANGPTL8/betatrophin does not control pancreatic beta cell expansion.

Recently, it was reported that angiopoietin-like protein 8 (ANGPTL8) was the long-sought "betatrophin" that could control pancreatic beta cell proliferation. However, studies of Angptl8(?/?) mice revealed profound reduction of triglyceride levels, but no abnormalities in glucose homeostasis. We now report that Angptl8(?/?) mice undergo entirely normal beta cell expansion in response to insulin resistance resulting from either a high-fat diet or from the administration of the insulin receptor antagonist S961. Furthermore, overexpression of ANGPTL8 in livers of mice doubles plasma triglyceride levels, but does not alter beta cell expansion nor glucose metabolism. These data indicate that ANGPTL8 does not play a role in controlling beta cell growth, nor can it be given to induce such expansion. The findings that plasma triglyceride levels are reduced by Angptl8 deletion and increased following ANGPTL8 overexpression support the possibility that inhibition of ANGPTL8 represents a therapeutic strategy for hypertriglyceridemia.

Structural basis of sensory receptor evolution in octopus.

Chemotactile receptors (CRs) are a cephalopod-specific innovation that allow octopuses to explore the seafloor via 'taste by touch'1. CRs diverged from nicotinic acetylcholine receptors to mediate contact-dependent chemosensation of insoluble molecules that do not readily diffuse in marine environments. Here we exploit octopus CRs to probe the structural basis of sensory receptor evolution. We present the cryo-electron microscopy structure of an octopus CR and compare it with nicotinic receptors to determine features that enable environmental sensation versus neurotransmission. Evolutionary, structural and biophysical analyses show that the channel architecture involved in cation permeation and signal transduction is conserved. By contrast, the orthosteric ligand-binding site is subject to diversifying selection, thereby mediating the detection of new molecules. Serendipitous findings in the cryo-electron microscopy structure reveal that the octopus CR ligand-binding pocket is exceptionally hydrophobic, enabling sensation of greasy compounds versus the small polar molecules detected by canonical neurotransmitter receptors. These discoveries provide a structural framework for understanding connections between evolutionary adaptations at the atomic level and the emergence of new organismal behaviour.

Sensory specializations drive octopus and squid behaviour.

The evolution of new traits enables expansion into new ecological and behavioural niches. Nonetheless, demonstrated connections between divergence in protein structure, function and lineage-specific behaviours remain rare. Here we show that both octopus and squid use cephalopod-specific chemotactile receptors (CRs) to sense their respective marine environments, but structural adaptations in these receptors support the sensation of specific molecules suited to distinct physiological roles. We find that squid express ancient CRs that more closely resemble related nicotinic acetylcholine receptors, whereas octopuses exhibit a more recent expansion in CRs consistent with their elaborated 'taste by touch' sensory system. Using a combination of genetic profiling, physiology and behavioural analyses, we identify the founding member of squid CRs that detects soluble bitter molecules that are relevant in ambush predation. We present the cryo-electron microscopy structure of a squid CR and compare this with octopus CRs1 and nicotinic receptors2. These analyses demonstrate an evolutionary transition from an ancestral aromatic 'cage' that coordinates soluble neurotransmitters or tastants to a more recent octopus CR hydrophobic binding pocket that traps insoluble molecules to mediate contact-dependent chemosensation. Thus, our study provides a foundation for understanding how adaptation of protein structure drives the diversification of organismal traits and behaviour.

Ranbp1 modulates morphogenesis of the craniofacial midline in mouse models of 22q11.2 deletion syndrome.

Facial dysmorphology is a hallmark of 22q11.2 deletion syndrome (22q11DS). Nearly all affected individuals have facial features characteristic of the syndrome: a vertically long face with broad nasal bridge, narrow palpebral fissures and mild micrognathia, sometimes accompanied by facial skeletal and oropharyngeal anomalies. Despite the frequency of craniofacial dysmorphology due to 22q11.2 deletion, there is still incomplete understanding of the contribution of individual 22q11 genes to craniofacial and oropharyngeal development. We asked whether homozygous or heterozygous loss of function of single 22q11 genes compromises craniofacial and/or oropharyngeal morphogenesis related to these 22q11DS phenotypes. We found that Ranbp1, a 22q11DS gene that mediates nucleocytoplasmic protein trafficking, is a dosage-dependent modulator of craniofacial development. Ranbp1-/- embryos have variably penetrant facial phenotypes, including altered facial morphology and cleft palate. This 22q11DS-related dysmorphology is particularly evident in the midline of the facial skeleton, as evidenced by a robustly quantifiable dysmorphology of the vomer, an unpaired facial midline bone. 22q11DS-related oropharyngeal phenotypes reflect Ranbp1 function in both the cranial neural crest and cranial ectoderm based upon tissue-selective Ranbp1 deletion. Analyses of genetic interaction show that Ranbp1 mutation disrupts BMP signaling-dependent midline gene expression and BMP-mediated craniofacial and cranial skeletal morphogenesis. Finally, midline defects that parallel those in Ranbp1 mutant mice are observed at similar frequencies in the LgDel 22q112DS mouse model. Apparently, Ranbp1 is a modulator of craniofacial development, and in the context of broader 22q11 deletion, Ranbp1 mutant phenotypes mirror key aspects of 22q11DS midline facial anomalies.

Plasma S1P Orchestrates the Reverse Transendothelial Migration of Aortic Intimal Myeloid Cells in Mice.

BACKGROUND: Myeloid cells (MCs) reside in the aortic intima at regions predisposed to atherosclerosis. Systemic inflammation triggers reverse transendothelial migration (RTM) of intimal MCs into the arterial blood, which orchestrates a protective immune response that clears intracellular pathogens from the arterial intima. Molecular pathways that regulate RTM remain poorly understood. S1P (sphingosine-1-phosphate) is a lipid mediator that regulates immune cell trafficking by signaling via 5 G-protein-coupled receptors (S1PRs [S1P receptors]). We investigated the role of S1P in the RTM of aortic intimal MCs. METHODS: Intravenous injection of lipopolysaccharide was used to model a systemic inflammatory stimulus that triggers RTM. CD11c+ intimal MCs in the lesser curvature of the ascending aortic arch were enumerated by en face confocal microscopy. Local gene expression was evaluated by transcriptomic analysis of microdissected intimal cells. RESULTS: In wild-type C57BL/6 mice, lipopolysaccharide induced intimal cell expression of S1pr1, S1pr3, and Sphk1 (a kinase responsible for S1P production). Pharmacological modulation of multiple S1PRs blocked lipopolysaccharide-induced RTM and modulation of S1PR1 and S1PR3 reduced RTM in an additive manner. Cre-mediated deletion of S1pr1 in MCs blocked lipopolysaccharide-induced RTM, confirming a role for myeloid-specific S1PR1 signaling. Global or hematopoietic deficiency of Sphk1 reduced plasma S1P levels, the abundance of CD11c+ MCs in the aortic intima, and blunted lipopolysaccharide-induced RTM. In contrast, plasma S1P levels, the abundance of intimal MCs, and lipopolysaccharide-induced RTM were rescued in Sphk1-/- mice transplanted with Sphk1+/+ or mixed Sphk1+/+ and Sphk1-/- bone marrow. Stimulation with lipopolysaccharide increased endothelial permeability and intimal MC exposure to circulating factors such as S1P. CONCLUSIONS: Functional and expression studies support a novel role for S1P signaling in the regulation of lipopolysaccharide-induced RTM and the homeostatic maintenance of aortic intimal MCs. Our data provide insight into how circulating plasma mediators help orchestrate intimal MC dynamics.

Oxidized Low-Density Lipoprotein Accumulation Suppresses Glycolysis and Attenuates the Macrophage Inflammatory Response by Diverting Transcription from the HIF-1α to the Nrf2 Pathway.

Lipid accumulation in macrophages (Mφs) is a hallmark of atherosclerosis, yet how lipid accumulation affects inflammatory responses through rewiring of Mφ metabolism is poorly understood. We modeled lipid accumulation in cultured wild-type mouse thioglycolate-elicited peritoneal Mφs and bone marrow-derived Mφs with conditional (Lyz2-Cre) or complete genetic deficiency of Vhl, Hif1a, Nos2, and Nfe2l2. Transfection studies employed RAW264.7 cells. Mφs were cultured for 24 h with oxidized low-density lipoprotein (oxLDL) or cholesterol and then were stimulated with LPS. Transcriptomics revealed that oxLDL accumulation in Mφs downregulated inflammatory, hypoxia, and cholesterol metabolism pathways, whereas the antioxidant pathway, fatty acid oxidation, and ABC family proteins were upregulated. Metabolomics and extracellular metabolic flux assays showed that oxLDL accumulation suppressed LPS-induced glycolysis. Intracellular lipid accumulation in Mφs impaired LPS-induced inflammation by reducing both hypoxia-inducible factor 1-α (HIF-1α) stability and transactivation capacity; thus, the phenotype was not rescued in Vhl-/- Mφs. Intracellular lipid accumulation in Mφs also enhanced LPS-induced NF erythroid 2-related factor 2 (Nrf2)-mediated antioxidative defense that destabilizes HIF-1α, and Nrf2-deficient Mφs resisted the inhibitory effects of lipid accumulation on glycolysis and inflammatory gene expression. Furthermore, oxLDL shifted NADPH consumption from HIF-1α- to Nrf2-regulated apoenzymes. Thus, we postulate that repurposing NADPH consumption from HIF-1α to Nrf2 transcriptional pathways is critical in modulating inflammatory responses in Mφs with accumulated intracellular lipid. The relevance of our in vitro models was established by comparative transcriptomic analyses, which revealed that Mφs cultured with oxLDL and stimulated with LPS shared similar inflammatory and metabolic profiles with foamy Mφs derived from the atherosclerotic mouse and human aorta.

Informing the Need for a SARS-CoV-2 Booster Based Upon the Immune Responses among Young Healthy Adults to Variants Circulating in Late 2023.

BACKGROUND: COVID-19 remains a global public health challenge due to new immune-evasive SARS-CoV-2 variants and heterogeneous immunity. METHODS: In this cross-sectional study, we evaluated the adaptive immune responses in U.S. active-duty personnel who completed a COVID-19 primary vaccine series and with heterogenous SARS-CoV-2 vaccination and infection histories to 3 previously dominant variants (Ancestral, Delta, BA.5) and 3 circulating variants (XBB.1.5, EG.5, and BA.2.86) in late 2023. Analyses were performed based upon timing (within or beyond 12 months) and type (vaccine or infection) of the most recent exposure. RESULTS: Significant reduction was observed in binding antibodies, neutralization antibodies, memory B cells, and CD8+ T cells against circulating variants compared to previous variants. The reduction in antibody response was more pronounced in those whose most recent exposure was greater than 12 months from enrollment. In contrast, the CD4+ T cell response was largely consistent across all tested variants. The type of most recent exposure was not a significant factor in determining the magnitude of current immune responses. CONCLUSIONS: Administration of the XBB.1.5-based booster is likely to enhance cross-reactive humoral responses against SARS-CoV-2 circulating lineages. Ongoing surveillance of immune responses to emerging variants is needed for informing vaccine composition and timing.

Identity, lineage and fates of a temporally distinct progenitor population in the embryonic olfactory epithelium.

We defined a temporally and transcriptionally divergent precursor cohort in the medial olfactory epithelium (OE) shortly after it differentiates as a distinct tissue at mid-gestation in the mouse. This temporally distinct population of Ascl1+ cells in the dorsomedial OE is segregated from Meis1+/Pax7+ progenitors in the lateral OE, and does not appear to be generated by Pax7+ lateral OE precursors. The medial Ascl1+ precursors do not yield a substantial number of early-generated ORNs. Instead, they first generate additional proliferative precursors as well as a distinct population of frontonasal mesenchymal cells associated with the migratory mass that surrounds the nascent olfactory nerve. Parallel to these in vivo distinctions, isolated medial versus lateral OE precursors in vitro retain distinct proliferative capacities and modes of division that reflect their in vivo identities. At later fetal stages, these early dorsomedial Ascl1+ precursors cells generate spatially restricted subsets of ORNs as well as other non-neuronal cell classes. Accordingly, the initial compliment of ORNs and other OE cell types is derived from at least two distinct early precursor populations: lateral Meis1/Pax7+ precursors that generate primarily early ORNs, and a temporally, spatially, and transcriptionally distinct subset of medial Ascl1+ precursors that initially generate additional OE progenitors and apparent migratory mass cells before yielding a subset of ORNs and likely supporting cell classes.

Infrapopliteal Endovascular Interventions for Claudication Are Associated with Poor Long-Term Outcomes in Medicare-Matched Registry Patients.

BACKGROUND: There are limited data supporting or opposing the use of infrapopliteal peripheral vascular interventions (PVI) for the treatment of claudication. OBJECTIVES: We aimed to evaluate the association of infrapopliteal PVI with long-term outcomes compared with isolated femoropopliteal PVI for the treatment of claudication. METHODS: We conducted a retrospective analysis of all patients in the Medicare-matched Vascular Quality Initiative database who underwent an index infrainguinal PVI for claudication from January 2004-December 2019 using Cox proportional hazards models. RESULTS: Of 14,261 patients (39.9% female; 85.6% age ≥65 years, 87.7% non-Hispanic white) who underwent an index infrainguinal PVI for claudication, 16.6% (N=2,369) received an infrapopliteal PVI. The median follow-up after index PVI was 3.7 years (IQR 2.1-6.1). Compared to patients who underwent isolated femoropopliteal PVI, patients receiving any infrapopliteal PVI had a higher 3-year cumulative incidence of conversion to CLTI (33.3% vs. 23.8%; P<0.001); repeat PVI (41.0% vs. 38.2%; P<0.01); and amputation (8.1% vs. 2.8%; P<0.001). After risk-adjustment, patients undergoing infrapopliteal PVI had a higher risk of conversion to CLTI (aHR 1.39, 95% CI, 1.25-1.53); repeat PVI (aHR 1.10, 95% CI, 1.01-1.19); and amputation (aHR 2.18, 95% CI, 1.77-2.67). Findings were consistent after adjusting for competing risk of death; in a 1:1 propensity-matched analysis; and in subgroup analyses stratified by TASC disease, diabetes, and end-stage kidney disease. CONCLUSIONS: Infrapopliteal PVI is associated with worse long-term outcomes than femoropopliteal PVI for claudication. These risks should be discussed with patients.

When Perfect Is the Enemy of Good: Results of a RAND Appropriateness Panel on Treat to Target in Asymptomatic IBD.

BACKGROUND: A treat-to-target strategy for inflammatory bowel disease (IBD) recommends iterative treatment adjustments to achieve clinical and endoscopic remission. In asymptomatic patients with ongoing endoscopic activity, the risk/benefit balance of this approach is unclear, particularly with prior exposure to advanced therapies. METHODS: Using the RAND/UCLA Appropriateness Method, 9 IBD specialists rated appropriateness of changing therapy in 126 scenarios of asymptomatic patients with ulcerative colitis (UC) and Crohn's disease (CD) and active endoscopic disease. Disease extent and behavior, prior treatment, prior complications, and recent disease progression were considered, as were factors that might influence decision-making, including age and pregnancy. Ratings were collected via anonymous survey, discussed at an in-person meeting, and finalized in a second anonymous survey. RESULTS: Panelists rated change in therapy as appropriate (i.e., expected benefit sufficiently outweighs potential harms from continuing therapy) in 96/126 scenarios, generally in patients with progressive, complicated, and/or extensive disease, while changing therapy was rated uncertain in 27 scenarios of mild and/or stable disease. Changing therapy was rated inappropriate in UC patients with mild and stable disease previously exposed to ≥3 therapies or with improved endoscopic activity, and in CD patients with only scattered aphthous ulcers. The validated threshold for disagreement was not crossed for any scenario. Patient age >65 years and a plan for pregnancy in the next year might influence decision-making in some settings. CONCLUSION: Appropriateness ratings can help guide clinical decision-making about changing therapy to achieve endoscopic remission in asymptomatic patients with IBD until data from ongoing randomized studies are available.

Transcriptional control of a metabolic switch regulating cellular methylation reactions is part of a common response to stress in divergent bee species.

Recent global declines in bee health have elevated the need for a more complete understanding of the cellular stress mechanisms employed by diverse bee species. We recently uncovered the biomarker lethal (2) essential for life [l(2)efl] genes as part of a shared transcriptional program in response to a number of cell stressors in the western honey bee (Apis mellifera). Here, we describe another shared stress-responsive gene, glycine N-methyltransferase (Gnmt), which is known as a key metabolic switch controlling cellular methylation reactions. We observed Gnmt induction by both abiotic and biotic stressors. We also found increased levels of the GNMT reaction product sarcosine in the midgut after stress, linking metabolic changes with the observed changes in gene regulation. Prior to this study, Gnmt upregulation had not been associated with cellular stress responses in other organisms. To determine whether this novel stress-responsive gene would behave similarly in other bee species, we first characterized the cellular response to endoplasmic reticulum (ER) stress in lab-reared adults of the solitary alfalfa leafcutting bee (Megachile rotundata) and compared this with age-matched honey bees. The novel stress gene Gnmt was induced in addition to a number of canonical gene targets induced in both bee species upon unfolded protein response (UPR) activation, suggesting that stress-induced regulation of cellular methylation reactions is a common feature of bees. Therefore, this study suggests that the honey bee can serve as an important model for bee biology more broadly, although studies on diverse bee species will be required to fully understand global declines in bee populations.

Infrapopliteal Peripheral Vascular Interventions for Claudication are Performed Frequently in the USA and Are Associated with Poor Long Term Outcomes.

OBJECTIVE: Infrapopliteal peripheral vascular interventions (PVIs) for claudication are still performed in the USA. This study aimed to evaluate whether infrapopliteal PVI is associated with worse long term outcomes than isolated femoropopliteal PVI for treatment of claudication. METHODS: A retrospective analysis of fee for service claims in a national administrative database was conducted using 100% of the Medicare fee for service claims between 2017 and 2019 to capture all Medicare beneficiaries who underwent an index infra-inguinal PVI for claudication. Hierarchical Cox proportional hazards models were performed to assess the association of infrapopliteal PVI with conversion to chronic limb threatening ischaemia (CLTI), repeat PVI, and major amputation. RESULTS: In total, 36 147 patients (41.1% female; 89.7% age ≥ 65 years; 79.0% non-Hispanic White ethnicity) underwent an index PVI for claudication, of whom 32.6% (n = 11 790) received an infrapopliteal PVI. Of these, 61.4% (n = 7 245) received a concomitant femoropopliteal PVI and 38.6% (n = 4 545) received an isolated infrapopliteal PVI. The median follow up time was 3.5 years (interquartile range 2.7, 4.3). Patients receiving infrapopliteal PVI had a higher three year cumulative incidence of conversion to CLTI (26.0%; 95% confidence interval [CI] 24.9 - 27.2% vs. 19.9%; 95% CI 19.1 - 20.7%), repeat PVI (56.0%; 95% CI 54.8 - 57.3% vs. 45.7%; 95% CI 44.9 - 46.6%), and major amputation (2.2%; 95% CI 1.8 - 2.6% vs. 1.3%; 95% CI 1.1 - 1.5%) compared with patients receiving isolated femoropopliteal PVI. After adjusting for patient and physician level characteristics, the risk of conversion to CLTI (adjusted hazard ratio [aHR] 1.31, 95% CI 1.23 - 1.39), repeat PVI (aHR 1.12, 95% CI 1.05 - 1.20), and major amputation (aHR 1.72, 95% CI 1.42 - 2.07) remained significantly higher for patients receiving infrapopliteal PVI. An increasing number of infrapopliteal vessels treated during the index intervention was associated with increasingly poor outcomes (p < .001 for trend). CONCLUSION: Infrapopliteal PVI for claudication is associated with worse long term outcomes relative to isolated femoropopliteal PVI.

Investigating the impact of suboptimal prescription of preoperative antiplatelets and statins on race and ethnicity-related disparities in major limb amputation.

BACKGROUND: Non-Hispanic Black and Hispanic patients with symptomatic PAD may receive different treatments than White patients with symptomatic PAD. The delivery of guideline-directed medical treatment may be a modifiable upstream driver of race and ethnicity-related disparities in outcomes such as limb amputation. The purpose of our study was to investigate the prescription of preoperative antiplatelets and statins in producing disparities in the risk of amputation following revascularization for symptomatic peripheral artery disease (PAD). METHODS: We used data from the Vascular Quality Initiative, a vascular procedure-based registry in the United States (2011-2018). We estimated the probability of preoperative antiplatelet and statin prescriptions and 1-year incidence of amputation. We then estimated the amputation risk difference between race/ethnicity groups that could be eliminated under a hypothetical intervention. RESULTS: Across 100,579 revascularizations, the 1-year amputation risk was 2.5% (2.4%, 2.6%) in White patients, 5.3% (4.9%, 5.6%) in Black patients, and 5.3% (4.7%, 5.9%) in Hispanic patients. Black (57.5%) and Hispanic patients (58.7%) were only slightly less likely than White patients (60.9%) to receive antiplatelet and statin therapy. However, the effect of antiplatelets and statins was greater in Black and Hispanic patients such that, had all patients received these medications, the estimated risk difference comparing Black to White patients would have reduced by 8.9% (-2.9%, 21.9%) and the risk difference comparing Hispanic to White patients would have been reduced by 17.6% (-0.7%, 38.6%). CONCLUSION: Even though guideline-directed care appeared evenly distributed by race/ethnicity, increasing access to such care may decrease health care disparities in major limb amputation.

Methylprednisolone dosing for pediatric critical asthma: a single-center cohort study.

OBJECTIVE: We aimed to characterize intravenous (IV) methylprednisolone (MP) dosing regimens and clinical outcomes for children hospitalized for critical asthma (CA). METHODS: A single-center, retrospective review was performed of children admitted to the pediatric intensive care unit (PICU) for CA between September 2015 and October 2019. Patients 5-to 17-year-olds, initiated on continuous nebulized albuterol, and prescribed at least one dose of IV MP were included. The primary outcome was to characterize PICU MP dosing. Cohorts were then compared by MP dosing: conservative-dose methylprednisolone (CDMP, ≤ 0.5 mg/kg/dose every 6 h) and standard-dose methylprednisolone (SDMP, > 0.5 mg/kg/dose every 6 h). Clinical efficacy endpoints were the duration of continuous nebulized albuterol and PICU length of stay (LOS). Safety endpoints included corticosteroid-related adverse events. RESULTS: Of 168 children studied, 50 (29.8%) were prescribed CDMP and 118 (70.2%) SDMP. The overall mean MP dose was 31.3 ± 19.6 mg (weight-adjusted: 0.77 ± 0.32 mg/kg/dose). Compared to those prescribed SDMP, those prescribed CDMP had a shorter median duration of continuous nebulized albuterol (12.8 [IQR: 10.5-20] versus 17.3 [IQR: 11.3-29.7] hours, p = 0.019) and median PICU LOS (0.9 [IQR: 0.7-1.4] versus 1.2 [IQR: 0.9-1.8] days, p = 0.012). No corticosteroid-related adverse events were observed. In adjusted models, weight-adjusted IV MP dose was not associated with PICU LOS or duration of continuous nebulized albuterol. CONCLUSIONS: Intravenous MP dosing for pediatric CA varied widely in our study sample. Prospective, controlled trials are required to validate our observations including clinical efficacy and safety endpoints.

Vitamin K Prescribing Trends Among Critically Ill Children Hospitalized for Sepsis: A Multicenter Observational Cohort Study.

Objective: Vitamin K (VK) is commonly prescribed for pediatric sepsis-induced coagulopathy without trial-derived evidence to support its use for this indication. The purpose of this study was to characterize national prescribing trends for VK in this population. Patients and Methods: This is a multicenter retrospective cohort study using the Pediatric Health Information System registry including children 0 to 17 years of age hospitalized for sepsis in the pediatric intensive care unit from January 2016 through December 2022. The primary outcome was overall, annual, and center-specific VK prescribing rates. Descriptive data included demographics, length of stay, and rates of VK deficiency, hepatic insufficiency, red blood cell (RBC) transfusion, venous thromboembolism (VTE), and mortality. VK prescribing trends were assessed using Joinpoint regression. Descriptive statistics employed included Wilcoxon rank-sum, student's t, and chi-square tests. Results: Of the 31 221 encounters studied, 4539 (14.6%) were prescribed VK (median center-specific rate: 14.2%; interquartile range [IQR]: 8.8-21%) with a linear annual trend decreasing from 17.3% in 2016 to 13.3% in 2022 (-0.6%/year, r2 = .661). Those prescribed VK had greater rates of hepatic dysfunction (20.5% vs 3.1%), RBC transfusion (26.5% vs 11.2%), VTE (12.5% vs 4.6%), mortality (17.1% vs 4.4%), and median length of stay (16 [IQR: 8-33] vs 8 [4-15] days) (all P < .001). VK deficiency was diagnosed in 0.2% of encounters. Conclusions: In this multicenter retrospective cohort, VK prescribing was common among critically ill children diagnosed with sepsis. Phased trials are needed to demonstrate clinical efficacy and safety for VK in this population.

Learned switch readiness via concurrent activation of task sets: Evidence from task specificity and memory load.

Cognitive flexibility increases when switch demands increase. In task switching experiments, repeated pairing of flexibility-demanding situations with specific contexts leads subjects to become more prepared to adapt to changing task demands in those contexts. One form of such upregulated cognitive flexibility has been demonstrated with a list-wide switch probability (LWSP) effect, where switch costs are smaller in lists with frequent switches than in lists with rare switches. According to a recent proposal, the LWSP effect is supported by a concurrent activation mechanism whereby both task rules are kept available simultaneously in working memory. We conducted four experiments to test two key features in this concurrent activation account of LWSP effects. First, we asked whether the LWSP effects are limited to only the trained tasks, and second, we asked whether concurrent working memory load would reduce the LWSP effects. In Experiment 1, we replicated and extended previous findings that the LWSP manipulation modulates both performance (switch costs) and voluntary switch rates, indicating that context-driven increases in flexibility are generalizable so long as the task-sets remain the same. Results of Experiments 2 and 3 showed that novel tasks do not benefit from the concurrent activation of the two other tasks, suggesting that the LWSP effect is task specific. Experiment 4 showed that holding additional information in working memory reduces the LWSP effect. While these findings support the hypothesis of concurrent activation underlying the increased flexibility in the LWSP effect, caveats remain; additional research is needed to further test this account.

Customized passive-dynamic ankle-foot orthoses can improve walking economy and speed for many individuals post-stroke.

BACKGROUND: Passive-dynamic ankle-foot orthoses (PD-AFOs) are often prescribed to address plantar flexor weakness during gait, which is commonly observed after stroke. However, limited evidence is available to inform the prescription guidelines of PD-AFO bending stiffness. This study assessed the extent to which PD-AFOs customized to match an individual's level of plantar flexor weakness influence walking function, as compared to No AFO and their standard of care (SOC) AFO. METHODS: Mechanical cost-of-transport, self-selected walking speed, and key biomechanical variables were measured while individuals greater than six months post-stroke walked with No AFO, with their SOC AFO, and with a stiffness-customized PD-AFO. Outcomes were compared across these conditions using a repeated measures ANOVA or Friedman test (depending on normality) for group-level analysis and simulation modeling analysis for individual-level analysis. RESULTS: Twenty participants completed study activities. Mechanical cost-of-transport and self-selected walking speed improved with the stiffness-customized PD-AFOs compared to No AFO and SOC AFO. However, this did not result in a consistent improvement in other biomechanical variables toward typical values. In line with the heterogeneous nature of the post-stroke population, the response to the PD-AFO was highly variable. CONCLUSIONS: Stiffness-customized PD-AFOs can improve the mechanical cost-of-transport and self-selected walking speed in many individuals post-stroke, as compared to No AFO and participants' standard of care AFO. This work provides initial efficacy data for stiffness-customized PD-AFOs in individuals post-stroke and lays the foundation for future studies to enable consistently effective prescription of PD-AFOs for patients post-stroke in clinical practice. TRIAL REGISTRATION: NCT04619043.

Pharmacist Initiated Interventions Using RxChange Message Communication with Prescribers for Electronic Prescriptions: A Retrospective Descriptive Study.

BACKGROUND: RxChange messages improve patient medication management by enhancing pharmacist-prescriber communication, but their usage patterns in the United States are not well-documented. OBJECTIVE: To determine intervention characteristics by pharmacists and prescribers using RxChange messages. METHODS: A retrospective analysis of electronic prescription and RxChange messages from 2022 and 2023, using data from Surescripts, LLC, was conducted. This included NewRx messages and RxChange Responses, categorized by seven RxChange use cases and Anatomical Therapeutic Chemical level 4 medication classes. Descriptive statistics and non-parametric tests were used for statistical analysis. RESULTS: The study analyzed 1,361,528 RxChange messages. Therapeutic interchange was the predominant use case (76.14%). Direct approvals accounted for 10.44% of requests, approvals with changes for 42.55%, and denials for 47.01%. Script clarification had the highest approval rate (64.21%), while prior authorization faced the most frequent denials (73.38%). The top denial reason was "Request addressed through alternate methods such as phone or fax" (41.50%). The most frequent drug classes observed in the data were selective beta-2 adrenoreceptor agonists, extended-spectrum penicillins, selective serotonin reuptake inhibitors, and glucagon-like peptide 1 analogues. Time from new e-prescription issuance to RxChange request submission was longer than from request to response, with a significant statistical difference (median 1.57 vs 0.27 days, p-value < 0.05). CONCLUSION: This study highlights interventions pharmacists make using RxChange with electronic prescriptions to improve patient care and medication safety. It underlined the need for improved RxChange message content and data on the effectiveness of RxChange messages in improving medication use.

Periprosthetic Joint Infection Risk After Primary Total Knee Arthroplasty: Are All Preoperative Corticosteroid Injections the Same?

BACKGROUND: Previous evidence has demonstrated an increased risk of periprosthetic joint infection (PJI) following primary total knee arthroplasty (TKA) in patients receiving corticosteroid injection (CSI) within 3 months of surgery. The study aimed to determine if PJI risk after TKA varied among different corticosteroid agents. METHODS: A total of 85,073 patients undergoing primary TKA from 2009 to 2019 were identified from a large national database. Of these, 1,092 (1.3%) received an ipsilateral, intra-articular CSI within 90 days of TKA. These patients were compared to those not receiving CSI using multivariate logistic regressions following 1:4 propensity score matching, with PJI development as the primary outcome. RESULTS: Patients given an injection of any corticosteroid within 90 days of TKA had significantly higher PJI rates compared to controls (1.6 versus 0.41%; P < .001). This finding was driven by patients receiving methylprednisolone acetate (n = 543) or betamethasone (n = 153), with prevalence rates of 1.7 and 2.6%, respectively (P = .003 and P = .01, respectively). No significant increase in the rate of PJI was observed for patients receiving triamcinolone (1.2%; P = .08; n = 342) or dexamethasone (0.0%; P = 1; n = 54) within 90 days preceding TKA. PJI risk for all agents, administered more than 90 days preoperatively normalized to control levels (0.51 versus 0.34%). CONCLUSIONS: These results suggest that PJI risk varies with CSI type. In this large database study, only patients given methylprednisolone acetate or betamethasone injections within 90 days of surgery had significantly higher PJI rates compared to controls.