Transient enhancement of stimulus-evoked activity in neocortex during sensory learning.

Synaptic potentiation has been linked to learning in sensory cortex, but the connection between this potentiation and increased sensory-evoked neural activity is not clear. Here, we used longitudinal in vivo Ca2+ imaging in the barrel cortex of awake mice to test the hypothesis that increased excitatory synaptic strength during the learning of a whisker-dependent sensory-association task would be correlated with enhanced stimulus-evoked firing. To isolate stimulus-evoked responses from dynamic, task-related activity, imaging was performed outside of the training context. Although prior studies indicate that multiwhisker stimuli drive robust subthreshold activity, we observed sparse activation of L2/3 pyramidal (Pyr) neurons in both control and trained mice. Despite evidence for excitatory synaptic strengthening at thalamocortical and intracortical synapses in this brain area at the onset of learning-indeed, under our imaging conditions thalamocortical axons were robustly activated-we observed that L2/3 Pyr neurons in somatosensory (barrel) cortex displayed only modest increases in stimulus-evoked activity that were concentrated at the onset of training. Activity renormalized over longer training periods. In contrast, when stimuli and rewards were uncoupled in a pseudotraining paradigm, stimulus-evoked activity in L2/3 Pyr neurons was significantly suppressed. These findings indicate that sensory-association training but not sensory stimulation without coupled rewards may briefly enhance sensory-evoked activity, a phenomenon that might help link sensory input to behavioral outcomes at the onset of learning.

Practical Guidance for Hemodynamic Assessment by Right Heart Catheterization in Management of Heart Failure.

Heart failure is a clinical syndrome characterized by the inability of the heart to meet the circulatory demands of the body without requiring an increase in intracardiac pressures at rest or with exertion. Hemodynamic parameters can be measured via right heart catheterization, which has an integral role in the full spectrum of heart failure: from ambulatory patients to those in cardiogenic shock, as well as patients being considered for left ventricular device therapy and heart transplantation. Hemodynamic data are critical for prompt recognition of clinical deterioration, assessment of prognosis, and guidance of treatment decisions. This review is a field guide for hemodynamic assessment, troubleshooting, and interpretation for clinicians treating patients with heart failure.

Impact of opioid overdoses on US life expectancy and years of life lost, by demographic group and stimulant co-involvement: a mortality data analysis from 2019 to 2022.

Background: The United States' opioid crisis is worsening, with the number of deaths reaching 81,806 in 2022 after more than tripling over the past decade. This study aimed to comprehensively characterize changes in burden of opioid overdose mortality in terms of life expectancy reduction and years of life lost between 2019 and 2022, including differential burden across demographic groups and the contribution of polysubstance use. Methods: Using life tables and counts for all-cause and opioid overdose deaths from the National Center for Health Statistics, we constructed cause-eliminated life tables to estimate mortality by age in the absence of opioid-related deaths. We calculated the loss in life expectancy at birth (LLE) and total years of life lost (YLL) due to opioid overdose deaths by state of residency, sex, racial/ethnic group, and co-involvement of cocaine and psychostimulants. Findings: Opioid-related deaths in the US led to an estimated 3.1 million years of life lost in 2022 (38 years per death), compared to 2.0 million years lost in 2019. Relative to a scenario with no opioid mortality, we estimate that opioid-related deaths reduced life expectancy nationally by 0.67 years in 2022 vs 0.52 years in 2019. This LLE worsened in all racial/ethnic groups during the study period: 0.76 y-0.96 y for white men, 0.36 y-0.55 y for white women, 0.59 y-1.1 y for Black men, 0.27 y-0.53 y for Black women, 0.31 y-0.82 y for Hispanic men, 0.19 y-0.31 y for Hispanic women, 0.62 y-1.5 y for American Indian/Alaska Native (AI/AN) men, 0.43 y-1 y for AI/AN women, 0.09 y-0.2 y for Asian men, and 0.08 y-0.13 y for Asian women. Nearly all states experienced an increase in years of life lost (YLL) per capita from 2019 to 2022, with YLL more than doubling in 16 states. Cocaine or psychostimulants with abuse potential (incl. methamphetamines) were involved in half of all deaths and years of life lost in 2022, with substantial variation in the predominant drug class by state and racial/ethnic group. Interpretation: The burden of opioid-related mortality increased dramatically in the US between 2019 and 2022, coinciding with the period of the COVID-19 pandemic and the associated disruptions to social, economic, and health systems. Opioid overdose deaths are an important contributor to decreasing US life expectancy, and Black, Hispanic, and Native Americans now experience mortality burdens approaching or exceeding white Americans. Funding: None.

Staff and client preferences for the design and delivery of an outcomes monitoring system in a mental health service.

BACKGROUND: Outcome monitoring can support the delivery of quality service that meets the needs of clients, clinicians and services. However, few studies have examined client or staff perspectives on the design and implementation of outcomes monitoring within a service. Implementation of outcomes monitoring requires understanding the preferences and expectations of relevant stakeholders. OBJECTIVE: Informed by the Consolidated Framework for Implementation Research, this study aimed to investigate the preferences and priorities of relevant staff, clients and family members to inform the design and implementation of an effective outcomes monitoring system in the context of a mental health service for military veterans and their families. METHOD: Twenty-nine staff participated across five online focus groups, including clinical staff, peer workers, policy staff and supervisors. Ten clients participated in online or telephone semi-structured interviews. Thematic analysis was used to develop themes from the data. RESULTS: Clients and staff agreed that outcomes monitoring should cover more than symptoms, particularly by incorporating functional outcomes. Assessing mental health over time was considered a valuable tool for supporting treatment processes and providing actionable information. Challenges identified by clients and staff included the need for efficient processes, ensuring measures are relevant and acceptable, and maintaining client privacy. The ability to personalise data collection and have a streamlined, responsive system were key attributes of a quality outcomes monitoring framework. CONCLUSIONS: Findings suggest that an effective outcome monitoring framework should be client-led, tailored to the individual's needs, and provide feedback on progress. Outcomes monitoring should also be efficient, accessible and allow for safe information sharing.

Quality assurance and other challenges in paediatric radiotherapy: Accurate delivery of craniospinal radiotherapy.

INTRODUCTION: Cranio-spinal radiotherapy (CSI) is used to treat central nervous system malignancies in paediatric, adolescent/young adult (AYA), and adult patients. Its delivery in the paediatric/AYA population is particularly challenging across different age groups. This study aims to assess the setup variations and dosimetric impact of CSI in paediatric and AYA patients. METHODS: This retrospective analysis included, 10 paediatric and AYA patients (aged 4-25) who underwent volumetric modulated arc therapy (VMAT) CSI between 2016 and 2022. Patient characteristics, diagnoses, prescribed CSI doses, and fractionation details were assessed. CT simulation and treatment planning followed standard protocols with setup errors were quantified by comparing daily treatment setup images with the planned position. The study evaluated the dosimetric impact on target volumes and organs at risk (OARs). RESULTS: The setup errors were identified, ranging from 0.5 to 6.2 mm in different directions, especially in the cranio-caudal direction. Despite these variations, there was minimal impact observed on the coverage of clinical target volumes (CTV) and doses to OARs (<1% relative change). CONCLUSION: Ensuring precise setup in paediatric and AYA patients undergoing CSI is essential to maintain adequate CTV coverage. Although occasional substantial setup variations occurred during treatment, they had a limited impact on CTV coverage and OAR doses when infrequent. Appropriate planning target volume (PTV) margins can effectively compensate for occasional shifts. However, systematic errors could compromise treatment quality if undetected. Regular off-line review of patient set-up trends is recommended.

Evaluating the performance of a risk assessment score tool to predict HIV acquisition among pregnant and postpartum women in Kenya.

BACKGROUND: Clinical risk score tools require validation in diverse settings and populations before they are widely implemented. We aimed to externally validate an HIV risk assessment tool for predicting HIV acquisition among pregnant and postpartum women. In the context of prevention of mother-to-child transmission programs, risk score tools could be used to prioritize retesting efforts and delivery of pre-exposure prophylaxis (PrEP) to pregnant and postpartum women most at risk for HIV acquisition while minimizing unnecessary perinatal exposure. METHODS: Data from women enrolled in a cross-sectional study of programmatic HIV retesting and/or receiving maternal and child health care services at five facilities in Western Kenya were used to validate the predictive ability of a simplified risk score previously developed for pregnant/postpartum women. Incident HIV infections were defined as new HIV diagnoses following confirmed negative or unknown status during pregnancy. Predictive performance was assessed using the area under the receiver operating characteristic curve (AUC) and Brier score. RESULTS: Among 1266 women with 35 incident HIV infections, we found an AUC for predicting HIV acquisition of 0.60 (95% CI, 0.51, 0.69), with a Brier score of 0.27. A risk score >6 was associated with a 2.9-fold increase in the odds of HIV acquisition (95% CI, 1.48, 5.70; p = 0.002) vs scores ≤6. Women with risk scores >6 were 27% (346/1266) of the population but accounted for 52% of HIV acquisitions. Syphilis, age at sexual debut, and unknown partner HIV status were significantly associated with increased risk of HIV in this cohort. CONCLUSION: The simplified risk score performed moderately at predicting risk of HIV acquisition in this population of pregnant and postpartum women and may be useful to guide PrEP use or counseling.

Seeking help as a strategy for ethical and professional decision-making in research: Perspectives of researchers from East Asia and the United States.

Background: A person's cultural background shapes how they interpret and navigate problems. Given that large numbers of international researchers work and train in the U.S. we sought to better understand how researchers use the decision-making strategy of seeking help to navigate ethical and professional challenges.Methods: Participants (N = 300) were researchers working or training in the U.S. who were born in East Asia (EA) or born in the U.S. They completed a screening survey; then a subset completed think-aloud interviews (n = 66) focused on how they would respond to three hypothetical research scenarios.Results: Thematic analysis of the transcripts showed that seeking help was a commonly endorsed strategy, with some nuances between groups. Themes included seeking help in the form of getting advice, seeking someone to help solve the problem, and gathering information. Endorsement of the seeking help strategy frequently depended on participants' relationships; desiring to seek help from people they trusted. Notably, EA participants tended to prefer seeking help in ways that avoided reputational harm to others.Conclusion: A better understanding of how researchers from different cultural backgrounds use decision-making strategies can inform how to make educational programs more inclusive and comprehensive to more effectively develop researchers' ethical and professional decision-making skills.

REDUCE missed oral healthcare: The outcomes of and learnings from an implementation project in an acute geriatric unit.

Oral healthcare is one of the most missed aspects of fundamental care. Failure to provide reliable and effective daily oral healthcare for older patients can lead to hospital-acquired pneumonias, longer hospital stays, increased health costs, and poor patient experience. The objective of this study was to codesign, implement, and evaluate an oral healthcare intervention for older adults in a geriatric unit. This mixed methods implementation project combined the hospital's quality improvement processes with the i-PARIHS knowledge translation framework. Multilevel facilitation guided the development of multidisciplinary implementation strategies, which were co-designed, tailored, and implemented at the ward and organizational level, targeting: awareness/engagement; clinical guideline development; building workforce capacity; access to appropriate products; patient awareness and support; utilization of multidisciplinary/dental referral pathways; and systematizing oral healthcare documentation. Gaps between evidence-based and current oral healthcare practice were identified through audits of practice and interviews with patients. Interviews and surveys with staff evaluated the feasibility and acceptability of the oral healthcare intervention and the success of implementation strategies. At the conclusion of the project, awareness, attitudes, and capacity of staff had increased, however, we could not demonstrate change in multidisciplinary oral healthcare practices or improvements for individual patients. Despite mixed success, the project informed discussions about including oral healthcare as a national healthcare standard for the acute care sector in Australia. Attempts to address oral healthcare may have started locally, but its impact was through policy change, which will empower health practitioners and managers to support practice change more widely.

Pre-existing parental stress and youth internalizing symptoms predict parent-reported COVID-related stress in military families.

Understanding the extent to which youth and families experienced COVID-related stress requires accounting for prior levels of stress and other associated factors. This is especially important for military families, which experience unique stressors and may be reluctant to seek outside help. In this prospective study, we examined the role of pre-pandemic family factors in predicting parent and youth stress during the COVID-19 pandemic. Participants were 234 families with at least one active-duty parent and a 3rd or 5th-grade child. Findings revealed that preexisting factors predicted youth and family COVID-related stress. Specifically, heightened pre-pandemic parental stress and youth internalizing symptoms were significant predictors of COVID-related stress. Implications for mental health professionals and other organizations supporting military parents and families during the COVID-19 pandemic as well as other times of upheaval are discussed.

A mechanically consistent unified formulation for fluid-porous-structure-contact interaction.

Fluid-structure interaction with contact poses profound mathematical and numerical challenges, particularly when considering realistic contact scenarios and the influence of surface roughness. Computationally, contact introduces challenges in altering the fluid domain topology and preserving stress balance. This work introduces a new mathematical framework for a unified continuum description of fluid-porous-structure-contact interaction (FPSCI), leveraging the Navier-Stokes-Brinkman (NSB) equations to incorporate porous effects within the surface asperities in the contact region. Our approach maintains mechanical consistency during contact, circumventing issues associated with contact models and complex interface coupling conditions, allowing for the modeling of tangential creeping flows due to surface roughness. The unified continuum and variational multiscale formulation ensure robustness by enabling stable and unified integration of fluid, porous, and solid sub-problems. Computational efficiency and ease of implementation - key advantages of our approach - are demonstrated by solving two benchmark problems of a falling ball and an idealized heart valve. This research has broad implications for fields reliant on accurate fluid-structure interactions and promising advancements in modeling and numerical simulation techniques.

Digital twinning of cardiac electrophysiology for congenital heart disease.

In recent years, blending mechanistic knowledge with machine learning has had a major impact in digital healthcare. In this work, we introduce a computational pipeline to build certified digital replicas of cardiac electrophysiology in paediatric patients with congenital heart disease. We construct the patient-specific geometry by means of semi-automatic segmentation and meshing tools. We generate a dataset of electrophysiology simulations covering cell-to-organ level model parameters and using rigorous mathematical models based on differential equations. We previously proposed Branched Latent Neural Maps (BLNMs) as an accurate and efficient means to recapitulate complex physical processes in a neural network. Here, we employ BLNMs to encode the parametrized temporal dynamics of in silico 12-lead electrocardiograms (ECGs). BLNMs act as a geometry-specific surrogate model of cardiac function for fast and robust parameter estimation to match clinical ECGs in paediatric patients. Identifiability and trustworthiness of calibrated model parameters are assessed by sensitivity analysis and uncertainty quantification.

A single-center, assessor-blinded, randomized controlled clinical trial to test the safety and efficacy of a novel brain-computer interface controlled functional electrical stimulation (BCI-FES) intervention for gait rehabilitation in the chronic stroke population.

BACKGROUND: In the United States, there are over seven million stroke survivors, with many facing gait impairments due to foot drop. This restricts their community ambulation and hinders functional independence, leading to several long-term health complications. Despite the best available physical therapy, gait function is incompletely recovered, and this occurs mainly during the acute phase post-stroke. Therapeutic options are limited currently. Novel therapies based on neurobiological principles have the potential to lead to long-term functional improvements. The Brain-Computer Interface (BCI) controlled Functional Electrical Stimulation (FES) system is one such strategy. It is based on Hebbian principles and has shown promise in early feasibility studies. The current study describes the BCI-FES clinical trial, which examines the safety and efficacy of this system, compared to conventional physical therapy (PT), to improve gait velocity for those with chronic gait impairment post-stroke. The trial also aims to find other secondary factors that may impact or accompany these improvements and establish the potential of Hebbian-based rehabilitation therapies. METHODS: This Phase II clinical trial is a two-arm, randomized, controlled, longitudinal study with 66 stroke participants in the chronic (> 6 months) stage of gait impairment. The participants undergo either BCI-FES paired with PT or dose-matched PT sessions (three times weekly for four weeks). The primary outcome is gait velocity (10-meter walk test), and secondary outcomes include gait endurance, range of motion, strength, sensation, quality of life, and neurophysiological biomarkers. These measures are acquired longitudinally. DISCUSSION: BCI-FES holds promise for gait velocity improvements in stroke patients. This clinical trial will evaluate the safety and efficacy of BCI-FES therapy when compared to dose-matched conventional therapy. The success of this trial will inform the potential utility of a Phase III efficacy trial. TRIAL REGISTRATION: The trial was registered as "BCI-FES Therapy for Stroke Rehabilitation" on February 19, 2020, at clinicaltrials.gov with the identifier NCT04279067.

Testing a Biobehavioral Model of Chronic Stress and Weight Gain in Young Children (Family Stress Study): Protocol and Baseline Demographics for a Prospective Observational Study.

BACKGROUND: Chronic stress is an important risk factor in the development of obesity. While research suggests chronic stress is linked to excess weight gain in children, the biological or behavioral mechanisms are poorly understood. OBJECTIVE: The objectives of the Family Stress Study are to examine behavioral and biological pathways through which chronic stress exposure (including stress from COVID-19) may be associated with adiposity in young children, and to determine if factors such as child sex, caregiver-child relationship quality, caregiver education, and caregiver self-regulation moderate the association between chronic stress and child adiposity. METHODS: The Family Stress Study is a prospective cohort study of families recruited from 2 Canadian sites: the University of Guelph in Guelph, Ontario, and McMaster University in Hamilton, Ontario. Participants will be observed for 2 years and were eligible to participate if they had at least one child (aged 2-6 years) and no plans to move from the area within the next 3 years. Study questionnaires and measures were completed remotely at baseline and will be assessed using the same methods at 1- and 2-year follow-ups. At each time point, caregivers measure and report their child's height, weight, and waist circumference, collect a hair sample for cortisol analysis, and fit their child with an activity monitor to assess the child's physical activity and sleep. Caregivers also complete a web-based health and behaviors survey with questions about family demographics, family stress, their own weight-related behaviors, and their child's mental health, as well as a 1-day dietary assessment for their child. RESULTS: Enrollment for this study was completed in December 2021. The final second-year follow-up was completed in April 2024. This study's sample includes 359 families (359 children, 359 female caregivers, and 179 male caregivers). The children's mean (SD) age is 3.9 years (1.2 years) and 51% (n=182) are female. Approximately 74% (n=263) of children and 80% (n=431) of caregivers identify as White. Approximately 34% (n=184) of caregivers have a college diploma or less and nearly 93% (n=499) are married or cohabiting with a partner. Nearly half (n=172, 47%) of the families have an annual household income ≥CAD $100,000 (an average exchange rate of 1 CAD=0.737626 USD applies). Data cleaning and analysis are ongoing as of manuscript publication. CONCLUSIONS: Despite public health restrictions from COVID-19, the Family Stress Study was successful in recruiting and using remote data collection to successfully engage families in this study. The results from this study will help identify the direction and relative contributions of the biological and behavioral pathways linking chronic stress and adiposity. These findings will aid in the development of effective interventions designed to modify these pathways and reduce obesity risk in children. TRIAL REGISTRATION: ClinicalTrials.gov NCT05534711; https://clinicaltrials.gov/study/NCT05534711. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/48549.

Improved multifidelity Monte Carlo estimators based on normalizing flows and dimensionality reduction techniques.

We study the problem of multifidelity uncertainty propagation for computationally expensive models. In particular, we consider the general setting where the high-fidelity and low-fidelity models have a dissimilar parameterization both in terms of number of random inputs and their probability distributions, which can be either known in closed form or provided through samples. We derive novel multifidelity Monte Carlo estimators which rely on a shared subspace between the high-fidelity and low-fidelity models where the parameters follow the same probability distribution, i.e., a standard Gaussian. We build the shared space employing normalizing flows to map different probability distributions into a common one, together with linear and nonlinear dimensionality reduction techniques, active subspaces and autoencoders, respectively, which capture the subspaces where the models vary the most. We then compose the existing low-fidelity model with these transformations and construct modified models with an increased correlation with the high-fidelity model, which therefore yield multifidelity estimators with reduced variance. A series of numerical experiments illustrate the properties and advantages of our approaches.

Effect of graft sizing in valve-sparing aortic root replacement for bicuspid aortic valve: The Goldilocks ratio.

Objective: To investigate the effect of graft sizing on valve performance in valve-sparing aortic root replacement for bicuspid aortic valve. Methods: In addition to a diseased control model, 3 representative groups-free-edge length to aortic/graft diameter (FELAD) ratio <1.3, 1.5 to 1.64, and >1.7-were replicated in explanted porcine aortic roots (n = 3) using straight grafts sized respective to the native free-edge length. They were run on a validated ex vivo univentricular system under physiological parameters for 20 cycles. All groups were tested within the same aortic root to minimize inter-root differences. Outcomes included transvalvular gradient, regurgitation fraction, and orifice area. Linear mixed effects model and pairwise comparisons were employed to compare outcomes across groups. Results: The diseased control had mean transvalvular gradient 10.9 ± 6.30 mm Hg, regurgitation fraction 32.5 ± 4.91%, and orifice area 1.52 ± 0.12 cm2. In ex vivo analysis, all repair groups had improved regurgitation compared with control (P < .001). FELAD <1.3 had the greatest amount of regurgitation among the repair groups (P < .001) and 1.5-1.64 the least (P < .001). FELAD <1.3 and >1.7 exhibited greater mean gradient compared with both control and 1.5 to 1.64 (P < .001). Among the repair groups, 1.5 to 1.64 had the largest orifice area, and >1.7 the smallest (P < .001). Conclusions: For a symmetric bicuspid aortic valve, performance after valve-sparing aortic root replacement shows a bimodal distribution across graft size. As the FELAD ratio departs from 1.5 to 1.64 in either direction, significant increases in transvalvular gradient are observed. FELAD <1.3 may also result in suboptimal improvement of baseline regurgitation.

Picturing the dance: intersections of gender, sexuality, and age in older women queer square dancers.

A dearth of research has focused on the diverse experiences of aging sexual minority populations and, in particular, older sexual minority women. Studies that have disaggregated the population of lesbian, gay, bisexual, transgender, questioning, queer, intersex and two-spirit (LGBTQIS+) older adults reveal that due to minority stress and a lifetime of disadvantage. Lesbians experience higher rates of chronic health conditions and mental health problems (including loneliness) than heterosexual women and greater financial inequalities compared to gay men or heterosexual women. Despite this, limited inquiry has explored the everyday lives of older queer women and fewer still draws upon women's commentary on their own lived experiences or centers older women as authoritative agents and experts on their own lives. In response to this knowledge deficit, this research traverses the aging experiences of female-identified members of a gay square dance (GSD) club in Toronto, Canada. We apply queer theory to explicate the unique ways in which a GSD club queers the aging process for 14 older women dancers. Findings of the inquiry highlight the ways in which these dancers confront and reject heteronormativity, while illuminating pathways to successful aging for older sexual diverse women. The older women dancers in this study perform gender in ways that challenged heteronormativity and gender binaries, enhanced belongingness and acceptance, embodied joy, and fostered wellness. These concepts have been identified as critical factors in successful aging and highlight what queering aging might look like for this resilient population who have overcome a lifetime of disadvantage.

Personalized coronary and myocardial blood flow models incorporating CT perfusion imaging and synthetic vascular trees.

Computational simulations of coronary artery blood flow, using anatomical models based on clinical imaging, are an emerging non-invasive tool for personalized treatment planning. However, current simulations contend with two related challenges - incomplete anatomies in image-based models due to the exclusion of arteries smaller than the imaging resolution, and the lack of personalized flow distributions informed by patient-specific imaging. We introduce a data-enabled, personalized and multi-scale flow simulation framework spanning large coronary arteries to myocardial microvasculature. It includes image-based coronary anatomies combined with synthetic vasculature for arteries below the imaging resolution, myocardial blood flow simulated using Darcy models, and systemic circulation represented as lumped-parameter networks. We propose an optimization-based method to personalize multiscale coronary flow simulations by assimilating clinical CT myocardial perfusion imaging and cardiac function measurements to yield patient-specific flow distributions and model parameters. Using this proof-of-concept study on a cohort of six patients, we reveal substantial differences in flow distributions and clinical diagnosis metrics between the proposed personalized framework and empirical methods based purely on anatomy; these errors cannot be predicted a priori. This suggests virtual treatment planning tools would benefit from increased personalization informed by emerging imaging methods.

Wireless wearable sensors can facilitate rapid detection of sleep apnea in hospitalized stroke patients.

STUDY OBJECTIVES: To evaluate wearable devices and machine learning for detecting sleep apnea in patients with stroke at an acute inpatient rehabilitation facility (IRF). METHODS: A total of 76 individuals with stroke wore a standard home sleep apnea test (ApneaLink Air), a multimodal, wireless wearable sensor system (ANNE), and a research-grade actigraphy device (ActiWatch) for at least one night during their first week after IRF admission as part of a larger clinical trial. Logistic regression algorithms were trained to detect sleep apnea using biometric features obtained from the ANNE sensors and ground truth apnea rating from the ApneaLink Air. Multiple algorithms were evaluated using different sensor combinations and different apnea detection criteria based on the Apnea-Hypopnea Index (AHI≥5, AHI≥15). RESULTS: Seventy-one (96%) participants wore the ANNE sensors for multiple nights. In contrast, only forty-eight participants (63%) could be successfully assessed for OSA by ApneaLink; 28 (37%) refused testing. The best-performing model utilized photoplethysmography (PPG) and finger temperature features to detect moderate-severe sleep apnea (AHI≥15), with 88% sensitivity and a positive likelihood ratio (LR+) of 44.00. This model was tested on additional nights of ANNE data achieving 71% sensitivity (10.14 LR+) when considering each night independently and 86% accuracy when averaging multi-night predictions. CONCLUSIONS: This research demonstrates the feasibility of accurately detecting moderate-severe sleep apnea early in the stroke recovery process using wearable sensors and machine learning techniques. These findings can inform future efforts to improve early detection for post-stroke sleep disorders, thereby enhancing patient recovery and long-term outcomes.

Impact of the Reverse 2-Step Algorithm for Clostridioides difficile Testing in the Microbiology Laboratory on Hospitalized Patients.

Background: Multistep laboratory testing is recommended for the diagnosis of Clostridioides difficile infection (CDI). The aim of this study was to present the impact of multistep CDI diagnostic testing in an academic hospital system and evaluate the toxin B gene polymerase chain reaction (PCR) cycle threshold (Ct) values of PCR-positive tests. Methods: In October 2022, our system began reflex testing all PCR-positive stool samples with the C. DIFF QUIK CHEK COMPLETE (Techlab), an enzyme immunoassay-based test with results for the glutamate dehydrogenase antigen (GDH) and C difficile toxin A/B. Hospital-onset (HO) CDI and CDI antibiotic use before and after testing were tracked. Ct values were obtained from the Infectious Diseases Diagnostic Laboratory. Receiver operating curve analysis was used to examine the sensitivity and specificity for identifying GDH+/toxin+ and GDH-/toxin- at various Ct thresholds. Results: The HO-CDI rate decreased from 0.352 cases per 1000 patient-days to 0.115 cases per 1000 patient-days post-reflex testing (P < .005). Anti-CDI antibiotics use decreased, but the decrease was not commensurate with CDI rates following reflex testing. PCR+/GDH+/toxin+ samples had a lower mean Ct value than PCR+/GDH-/toxin- samples (23.3 vs 33.5, P < .0001). A Ct value of 28.65 could distinguish between those 2 groups. Fifty-four percent of PCR+/GDH+/toxin- samples had a Ct value below that cut-off, suggesting the possibility of CDI with a negative toxin test. Conclusions: Reflex testing for a laboratory diagnosis of CDI results in rapid, systemwide decreases in the rate of HO-CDI. Additional research is needed to distinguish CDI from C difficile colonization in patients with discordant testing.

Kinetics of SARS-CoV-2 infection biomarkers in a household transmission study.

SARS-CoV-2 is the causative agent of COVID-19. Timely and accurate diagnostic testing is vital to contain the spread of infection, reduce delays in treatment and care, and inform patient management. Optimal specimen type (e.g. nasal swabs or saliva), timing of sampling, viral marker assayed (RNA or antigen), and correlation with viral infectivity and COVID-19 symptoms severity remain incompletely defined. We conducted a field study to evaluate SARS-CoV-2 viral marker kinetics starting from very early times after infection. We measured RNA and antigen levels in nasal swabs and saliva, virus outgrowth in cell culture from nasal swabs, and antibody levels in blood in a cohort of 30 households. Nine household contacts (HHC) became infected with SARS-CoV-2 during the study. Viral RNA was detected in saliva specimens approximately 1-2 days before nasal swabs in six HHC. Detection of RNA was more sensitive than of antigen, but antigen detection was better correlated with culture positivity, a proxy for contagiousness. Anti-nucleocapsid antibodies peaked one to three weeks post-infection. Viral RNA and antigen levels were higher in specimens yielding replication competent virus in cell culture. This study provides important data that can inform how to optimally interpret SARS-CoV-2 diagnostic test results.