Pediatric Primary Care Clinicians' Perspectives on Telemedicine Use, 2020 Versus 2021.

Objective: We examined the change in pediatric primary care clinician attitudes and perceptions about telemedicine after one year of telemedicine use. Methods: We administered a survey to pediatric primary care clinicians across 50 primary care practices in Pennsylvania in 2020 and 2021. Surveys were linked using a combination of deterministic and probabilistic matching. We used McNemar's test to compare change in responses from 2020 to 2021. Results: Among pediatric primary care clinicians surveyed in 2020 and 2021 (n = 101), clinicians agreed that telemedicine could always or usually deliver high-quality care for mental health (80% in 2020 and 78% in 2021), care coordination (77% in 2020 and 70% in 2021), acute care (33% in 2020 and 34% in 2021), or preventive care (25% in 2020 and 18% in 2021) and this did not significantly change. Clinician perceptions of usability, while high, declined over time with fewer endorsing ease of use (93% in 2020 and 80% in 2021) and reliability (14% in 2020 and 0% in 2021) over time. Despite this, 62% of clinicians agreed that they were satisfied with their use of telemedicine at both time points. Respondents anticipated positive impact on equity and timeliness of care from telemedicine use but did not anticipate positive impact across child health, health care delivery, or clinician experience. Perceptions across these domains did not change over time. Conclusions: With one year of telemedicine experience, primary care clinicians maintained beliefs that telemedicine could deliver high-quality care for specific clinical needs but had worsening perceptions of usability over time.

Survival Modelling For Data From Combined Cohorts: Opening the Door to Meta Survival Analyses and Survival Analysis using Electronic Health Records.

Non-parametric estimation of the survival function using observed failure time data depends on the underlying data generating mechanism, including the ways in which the data may be censored and/or truncated. For data arising from a single source or collected from a single cohort, a wide range of estimators have been proposed and compared in the literature. Often, however, it may be possible, and indeed advantageous, to combine and then analyze survival data that have been collected under different study designs. We review non-parametric survival analysis for data obtained by combining the most common types of cohort. We have two main goals: (i) To clarify the differences in the model assumptions, and (ii) to provide a single lens through which some of the proposed estimators may be viewed. Our discussion is relevant to the meta analysis of survival data obtained from different types of study, and to the modern era of electronic health records.

Tbx18 Orchestrates Cytostructural Transdifferentiation of Cardiomyocytes to Pacemaker Cells by Recruiting the Epithelial-Mesenchymal Transition Program.

Previously, we reported that heterologous expression of an embryonic transcription factor, Tbx18, reprograms ventricular cardiomyocytes into induced pacemaker cells (Tbx18-iPMs), though the key pathways are unknown. Here, we have used a tandem mass tag proteomic approach to characterize the impact of Tbx18 on neonatal rat ventricular myocytes. Tbx18 expression triggered vast proteome remodeling. Tbx18-iPMs exhibited increased expression of known pacemaker ion channels, including Hcn4 and Cx45 as well as upregulation of the mechanosensitive ion channels Piezo1, Trpp2 (PKD2), and TrpM7. Metabolic pathways were broadly downregulated, as were ion channels associated with ventricular excitation-contraction coupling. Tbx18-iPMs also exhibited extensive intracellular cytoskeletal and extracellular matrix remodeling, including 96 differentially expressed proteins associated with the epithelial-to-mesenchymal transition (EMT). RNAseq extended coverage of low abundance transcription factors, revealing upregulation of EMT-inducing Snai1, Snai2, Twist1, Twist2, and Zeb2. Finally, network diffusion mapping of >200 transcriptional regulators indicates EMT and heart development factors occupy adjacent network neighborhoods downstream of Tbx18 but upstream of metabolic control factors. In conclusion, transdifferentiation of cardiac myocytes into pacemaker cells entails massive electrogenic, metabolic, and cytostructural remodeling. Structural changes exhibit hallmarks of the EMT. The results aid ongoing efforts to maximize the yield and phenotypic stability of engineered biological pacemakers.

Asthma as a risk factor for hospitalization in children with COVID-19: A nested case-control study.

BACKGROUND: Most pediatric studies of asthma and COVID-19 to date have been ecological, which offer limited insight. We evaluated the association between asthma and COVID-19 at an individual level. METHODS: Using data from prospective clinical registries, we conducted a nested case-control study comparing three groups: children with COVID-19 and underlying asthma ("A+C" cases); children with COVID-19 without underlying disease ("C+" controls); and children with asthma without COVID-19 ("A+" controls). RESULTS: The cohort included 142 A+C cases, 1110 C+ controls, and 140 A+ controls. A+C cases were more likely than C+ controls to present with dyspnea and wheezing, to receive pharmacologic treatment including systemic steroids (all p < .01), and to be hospitalized (4.9% vs. 1.7%, p = .01). In the adjusted analysis, A+C cases were nearly 4 times more likely to be hospitalized than C+ controls (adjusted OR = 3.95 [95%CI = 1.4-10.9]); however, length of stay and respiratory support level did not differ between groups. Among A+C cases, 8.5% presented with an asthma exacerbation and another 6.3% developed acute exacerbation symptoms shortly after testing positive for SARS-CoV-2. Compared to historic A+ controls, A+C cases had less severe asthma, were less likely to be on controller medications, and had better asthma symptom control (all p < .01). CONCLUSIONS: In our cohort, asthma was a risk factor for hospitalization in children with COVID-19, but not for worse COVID-19 outcomes. SARS-CoV-2 does not seem to be a strong trigger for pediatric asthma exacerbations. Asthma severity was not associated with higher risk of COVID-19.

Using piecewise regression to identify biological phenomena in biotelemetry datasets.

Technological advances in the field of animal tracking have greatly expanded the potential to remotely monitor animals, opening the door to exploring how animals shift their behaviour over time or respond to external stimuli. A wide variety of animal-borne sensors can provide information on an animal's location, movement characteristics, external environmental conditions and internal physiological status. Here, we demonstrate how piecewise regression can be used to identify the presence and timing of potential shifts in a variety of biological responses using multiple biotelemetry data streams. Different biological latent states can be inferred by partitioning a time-series into multiple segments based on changes in modelled responses (e.g. their mean, variance, trend, degree of autocorrelation) and specifying a unique model structure for each interval. We provide six example applications highlighting a variety of taxonomic species, data streams, timescales and biological phenomena. These examples include a short-term behavioural response (flee and return) by a trumpeter swan Cygnus buccinator following a GPS collar deployment; remote identification of parturition based on movements by a pregnant moose Alces alces; a physiological response (spike in heart-rate) in a black bear Ursus americanus to a stressful stimulus (presence of a drone); a mortality event of a trumpeter swan signalled by changes in collar temperature and overall dynamic body acceleration; an unsupervised method for identifying the onset, return, duration and staging use of sandhill crane Antigone canadensis migration; and estimation of the transition between incubation and brood-rearing (i.e. hatching) for a breeding trumpeter swan. We implement analyses using the mcp package in R, which provides functionality for specifying and fitting a wide variety of user-defined model structures in a Bayesian framework and methods for assessing and comparing models using information criteria and cross-validation measures. These simple modelling approaches are accessible to a wide audience and offer a straightforward means of assessing a variety of biologically relevant changes in animal behaviour.

Stacked survival models for residual lifetime data.

When modelling the survival distribution of a disease for which the symptomatic progression of the associated condition is insidious, it is not always clear how to measure the failure/censoring times from some true date of disease onset. In a prevalent cohort study with follow-up, one approach for removing any potential influence from the uncertainty in the measurement of the true onset dates is through the utilization of only the residual lifetimes. As the residual lifetimes are measured from a well-defined screening date (prevalence day) to failure/censoring, these observed time durations are essentially error free. Using residual lifetime data, the nonparametric maximum likelihood estimator (NPMLE) may be used to estimate the underlying survival function. However, the resulting estimator can yield exceptionally wide confidence intervals. Alternatively, while parametric maximum likelihood estimation can yield narrower confidence intervals, it may not be robust to model misspecification. Using only right-censored residual lifetime data, we propose a stacking procedure to overcome the non-robustness of model misspecification; our proposed estimator comprises a linear combination of individual nonparametric/parametric survival function estimators, with optimal stacking weights obtained by minimizing a Brier Score loss function.

Practice-Level Variation in Telemedicine Use in a Pediatric Primary Care Network During the COVID-19 Pandemic: Retrospective Analysis and Survey Study.

BACKGROUND: Telehealth, the delivery of health care through telecommunication technology, has potential to address multiple health system concerns. Despite this potential, only 15% of pediatric primary care clinicians reported using telemedicine as of 2016, with the majority identifying inadequate payment for these services as the largest barrier to their adoption. The COVID-19 pandemic led to rapid changes in payment and regulations surrounding telehealth, enabling its integration into primary care pediatrics. OBJECTIVE: Due to limited use of telemedicine in primary care pediatrics prior to the COVID-19 pandemic, much is unknown about the role of telemedicine in pediatric primary care. To address this gap in knowledge, we examined the association between practice-level telemedicine use within a large pediatric primary care network and practice characteristics, telemedicine visit diagnoses, in-person visit volumes, child-level variations in telemedicine use, and clinician attitudes toward telemedicine. METHODS: We analyzed electronic health record data from 45 primary care practices and administered a clinician survey to practice clinicians. Practices were stratified into tertiles based on rates of telemedicine use (low, intermediate, high) per 1000 patients per week during a two-week period (April 19 to May 2, 2020). By practice tertile, we compared (1) practice characteristics, (2) telemedicine visit diagnoses, (3) rates of in-person visits to the office, urgent care, and the emergency department, (4) child-level variation in telemedicine use, and (5) clinician attitudes toward telemedicine across these practices. RESULTS: Across pediatric primary care practices, telemedicine visit rates ranged from 5 to 23 telemedicine visits per 1000 patients per week. Across all tertiles, the most frequent telemedicine visit diagnoses were mental health (28%-36% of visits) and dermatologic (15%-28%). Compared to low telemedicine use practices, high telemedicine use practices had fewer in-person office visits (10 vs 16 visits per 1000 patients per week, P=.005) but more total encounters overall (in-office and telemedicine: 28 vs 22 visits per 1000 patients per week, P=.006). Telemedicine use varied with child age, race and ethnicity, and recent preventive care; however, no significant interactions existed between these characteristics and practice-level telemedicine use. Finally, clinician attitudes regarding the usability and impact of telemedicine did not vary significantly across tertiles. CONCLUSIONS: Across a network of pediatric practices, we identified significant practice-level variation in telemedicine use, with increased use associated with more varied telemedicine diagnoses, fewer in-person office visits, and increased overall primary care encounter volume. Thus, in the context of the pandemic, when underutilization of primary care was prevalent, higher practice-level telemedicine use supported pediatric primary care encounter volume closer to usual rates. Child-level telemedicine use differed by child age, race and ethnicity, and recent preventive care, building upon prior concerns about differences in access to telemedicine. However, increased practice-level use of telemedicine services was not associated with reduced or increased differences in use, suggesting that further work is needed to promote equitable access to primary care telemedicine.

Nested case-control study designs for left-truncated survival data.

The determination of risk factors for disease incidence has been the subject of much epidemiologic research. With this goal a common study design entails the follow-up of an initially disease-free cohort, keeping track of the dates of disease incidence (onset) and ascertaining covariate (putative risk factor) information on the full cohort. However, the collection of certain covariate information on all study subjects may be prohibitively expensive and, therefore, the nested case-control study has commonly been used. The high cost of full covariate information on all subjects also arises when determining risk factors for "failure," death say, "following" disease onset, in particular, in a prevalent cohort study with follow-up; in such a study a cohort of subjects with existing disease is followed. We here adapt nested case-control designs to the setting of a prevalent cohort study with follow-up, a topic previously not addressed in the literature. We provide the partial likelihood under risk set sampling and state the asymptotic properties of the estimated covariate effects and baseline cumulative hazard. We address the following design questions in the context of prevalent cohort studies with follow-up: How many subjects should be included in the sampled risk sets for efficient estimation? In what way is the proportion of censored subjects associated with the benefit of a nested case-control design? What proportion of overall variance is attributable to risk set sampling? This work is motivated by the anticipated analysis of data on survival with Parkinson's Disease, being collected as part of the ongoing Canadian Longitudinal Study on Aging.

La détermination des facteurs de risque pour l'incidence d'une maladie est le sujet de nombreuses études épidémiologiques. À cet effet, un plan d'expérience commun consiste à suivre une cohorte initialement en santé en prenant note de la date à laquelle la maladie se manifeste (début) et en évaluant les covariables (facteurs de risque présumés) pour la cohorte en entier. Lorsque la collecte de certaines covariables pour tous les individus s'avère trop onéreuse, une étude cas-témoins peut eˆtre considérée. Un problème similaire de couˆts élevés pour la collecte d'information sur tous les sujets peut également se présenter lorsque les facteurs de risque pour un « échec ¼, disons le décès, doivent eˆtre déterminés après le début de la maladie. Une telle situation peut survenir dans une étude sur une cohorte prévalente avec suivi, mais la question n'a pas encore été traitée dans la littérature. Les auteurs développent la vraisemblance partielle pour un échantillonnage dans l'ensemble à risque et décrivent les propriétés asymptotiques des estimés de l'effet des covariables et de la fonction cumulative du risque de base. Ils répondent à certaines questions émergeant d'un plan d'expérience pour une cohorte prévalente avec suivi, notamment le nombre de sujets à inclure dans l'ensemble de risque pour obtenir une estimation efficace, les façons dont la proportion de sujets censurés est liée aux bénéfices d'un plan cas-témoin imbriqué, et la proportion de variance globale attribuable à l'échantillonnage dans l'ensemble à risque. Le développement de ces méthodes est motivé par l'analyse imminente de données de survie de patients atteints de la maladie de Parkinson dont la collecte est en cours dans le cadre de l'é tude longitudinale canadienne sur le vieillissement.

DJ-1 protects the heart against ischemia-reperfusion injury by regulating mitochondrial fission.

Recent data indicates that DJ-1 plays a role in the cellular response to stress. Here, we aimed to examine the underlying molecular mechanisms mediating the actions of DJ-1 in the heart following myocardial ischemia-reperfusion (I/R) injury. In response to I/R injury, DJ-1 KO mice displayed increased areas of infarction and worsened left ventricular function when compared to WT mice, confirming a protective role for DJ-1 in the heart. In an effort to evaluate the potential mechanism(s) responsible for the increased injury in DJ-1 KO mice, we focused on SUMOylation, a post-translational modification process that regulates various aspects of protein function. DJ-1 KO hearts after I/R injury were found to display enhanced accumulation of SUMO-1 modified proteins and reduced SUMO-2/3 modified proteins. Further analysis, revealed that the protein expression of the de-SUMOylation enzyme SENP1 was reduced, whereas the expression of SENP5 was enhanced in DJ-1 KO hearts after I/R injury. Finally, DJ-1 KO hearts were found to display enhanced SUMO-1 modification of dynamin-related protein 1, excessive mitochondrial fission, and dysfunctional mitochondria. Our data demonstrates that the activation of DJ-1 in response to myocardial I/R injury protects the heart by regulating the SUMOylation status of Drp1 and attenuating excessive mitochondrial fission.

The EnvIMS Study: Design and Methodology of an International Case-Control Study of Environmental Risk Factors in Multiple Sclerosis.

BACKGROUND: Multiple sclerosis (MS) is a chronic disease of the central nervous system, often resulting in significant neurological disability. The causes of MS are not known; however, the incidence of MS is increasing, thereby suggesting that changes in lifestyle and/or environmental factors may be responsible. On this background, the Environmental Risk Factors in MS Study or EnvIMS study was designed to further explore the etiology of MS. The design and methodology are described, providing details to enable investigators to (i) use our experiences to design their own studies; (ii) take advantage of, and build on the methodological work completed for, the EnvIMS study; (iii) become aware of this data source that is available for use by the research community. METHODS: EnvIMS is a multinational case-control study, enrolling 2,800 cases with MS and 5,012 population-based controls in Canada, Italy, Norway, Serbia and Sweden. The study was designed to investigate the most commonly implicated risk factors for MS etiology using a self-report questionnaire. RESULTS/CONCLUSIONS: The use of a common methodology to study MS etiology across several countries enhances the comparability of results in different geographic regions and research settings, reduces the resources required for study design and enhances the opportunity for data harmonization.

The effect of surface morphology on the primary fixation strength of uncemented femoral knee prosthesis: a cadaveric study.

We investigated the effect of surface morphology on the mechanical performance of uncemented femoral knee prosthesis. Eighteen implants were implanted on nine paired femurs and then pushed-off (left legs: a novel surface morphology; right legs: Porocoat as baseline). Bone mineral density (BMD) and anteroposterior dimension were not significantly different between groups. The insertion force was not significantly different, however, the loosening force was significantly higher in the novel group (P=0.007). BMD had a direct relationship with the insertion and loosening force (P<0.001). The effect of surface morphology on implant alignment was very small. We conclude that the surface properties create a higher frictional resistance, thereby providing a better inherent stability of implants featuring the novel surface morphology.

The survival function NPMLE for combined right-censored and length-biased right-censored failure time data: properties and applications.

Many cohort studies in survival analysis have imbedded in them subcohorts consisting of incident cases and prevalent cases. Instead of analysing the data from the incident and prevalent cohorts alone, there are surely advantages to combining the data from these two subcohorts. In this paper, we discuss a survival function nonparametric maximum likelihood estimator (NPMLE) using both length-biased right-censored prevalent cohort data and right-censored incident cohort data. We establish the asymptotic properties of the survival function NPMLE and utilize the NPMLE to estimate the distribution for time spent in a Montreal area hospital.

Quantification of long-term nonlinear stress relaxation of bovine trabecular bone.

The reliability of computational models in orthopedic biomechanics depends often on the accuracy of the bone material properties. It is widely recognized that the mechanical response of trabecular bone is time-dependent, yet it is often ignored for the sake of simplicity. Previous investigations into the viscoelastic properties of trabecular bone have not explored the relationship between nonlinear stress relaxation and bone mineral density. The inclusion of this behavior could enhance the accuracy of simulations of orthopedic interventions, such as of primary fixation of implants. Although methods to quantify the viscoelastic behavior are known, the time period during which the viscoelastic properties should be investigated to obtain reliable predictions is currently unclear. Therefore, this study aimed to: 1) Investigate the duration of stress relaxation in bovine trabecular bone; 2) construct a material model that describes the nonlinear viscoelastic behavior of uniaxial stress relaxation experiments on trabecular bone; and 3) implement bone density into this model. Uniaxial compressive stress relaxation experiments were performed with cylindrical bovine femoral trabecular bone samples (n = 16) with constant strain held for 24 h. Additionally, multiple stress relaxation experiments with four ascending strain levels with a holding time of 30 min, based on the results of the 24-h experiment, were executed on 18 bovine bone cores. The bone specimens used in this study had a mean diameter of 12.80 mm and a mean height of 28.70 mm. A Schapery and a Superposition model were used to capture the nonlinear stress relaxation behavior in terms of applied strain level and bone mineral density. While most stress relaxation happened in the first 10 min (up to 53 %) after initial compression, the stress relaxation continued even after 24 h. Up to 69 % of stress relaxation was observed at 24 h. Extrapolating the results of 30 min of experimental data to 24 h provided a good fit for accuracy with much improved experimental efficiency. The Schapery and Superposition model were both capable of fitting the repeated stress relaxation in a sample-by-sample approach. However, since bone mineral density did not influence the time-dependent behavior, only the Superposition model could be used for a group-based model fit. Although the sample-by-sample approach was more accurate for an individual specimen, the group based approach is considered a useful model for general application.

Simulated microgravity improves maturation of cardiomyocytes derived from human induced pluripotent stem cells.

Cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CMs) possess tremendous potential for basic research and translational application. However, these cells structurally and functionally resemble fetal cardiomyocytes, which is a major limitation of these cells. Microgravity can significantly alter cell behavior and function. Here we investigated the effect of simulated microgravity on hiPSC-CM maturation. Following culture under simulated microgravity in a random positioning machine for 7 days, 3D hiPSC-CMs had increased mitochondrial content as detected by a mitochondrial protein and mitochondrial DNA to nuclear DNA ratio. The cells also had increased mitochondrial membrane potential. Consistently, simulated microgravity increased mitochondrial respiration in 3D hiPSC-CMs, as indicated by higher levels of maximal respiration and ATP content, suggesting improved metabolic maturation in simulated microgravity cultures compared with cultures under normal gravity. Cells from simulated microgravity cultures also had improved Ca2+ transient parameters, a functional characteristic of more mature cardiomyocytes. In addition, these cells had improved structural properties associated with more mature cardiomyocytes, including increased sarcomere length, z-disc length, nuclear diameter, and nuclear eccentricity. These findings indicate that microgravity enhances the maturation of hiPSC-CMs at the structural, metabolic, and functional levels.

Transient pacing in pigs with complete heart block via myocardial injection of mRNA coding for the T-box transcription factor 18.

The adenovirus-mediated somatic transfer of the embryonic T-box transcription factor 18 (TBX18) gene can convert chamber cardiomyocytes into induced pacemaker cells. However, the translation of therapeutic TBX18-induced cardiac pacing faces safety challenges. Here we show that the myocardial expression of synthetic TBX18 mRNA in animals generates de novo pacing and limits innate and inflammatory immune responses. In rats, intramyocardially injected mRNA remained localized, whereas direct myocardial injection of an adenovirus carrying a reporter gene resulted in diffuse expression and in substantial spillover to the liver, spleen and lungs. Transient expression of TBX18 mRNA in rats led to de novo automaticity and pacemaker properties and, compared with the injection of adenovirus, to substantial reductions in the expression of inflammatory genes and in activated macrophage populations. In rodent and clinically relevant porcine models of complete heart block, intramyocardially injected TBX18 mRNA provided rate-adaptive cardiac pacing for one month that strongly correlated with the animal's sinus rhythm and physical activity. TBX18 mRNA may aid the development of biological pacemakers.

Efficacy of a digital mental health intervention embedded in routine care compared with treatment as usual in adolescents and young adults with moderate depressive symptoms: protocol for randomised controlled trial.

INTRODUCTION: There are unmet mental health needs of depressed adolescents and young adults (AYAs) across the USA. Behavioural technology adequately integrated into clinical care delivery has potential to improve care access and efficiency. This multisite randomised controlled trial evaluates how a coach-enhanced digital cognitive behavioural intervention (dCBI) enhances usual care for depressed AYAs in paediatric practices with minority enriched samples. METHODS AND ANALYSIS: Participants (n=750) ages 16-22 who meet threshold criteria for depressive severity (Patient Health Questionnaire-9; PHQ-9 score 10-24) will be recruited through paediatric practices across three academic institutions (Boston, Pittsburgh and San Diego). Participants will be randomised to 12 weeks of dCBI+treatment as usual (TAU) (n=450) or TAU alone (n=300) in outpatient paediatric practices. Assessments will be completed at baseline, 6 weeks and 12 weeks with the primary outcome being improvement in clinician-rated and self-reported depressive severity (Children's Depression Rating Scale-Revised and PHQ-9) and secondary outcomes being self-reported suicidal ideation (item 9 on PHQ-9), anxiety severity (Generalised Anxiety Disorder), general quality of life (Satisfaction with Life Scale) and general functioning (Children's Global Assessment Scale). The study design is an intent-to-treat mixed effects regression with group, and covariates nested within the sites. ETHICS AND DISSEMINATION: All participants or their parent/guardian (under 18 years or unemancipated) will give informed consent to a study team member. All data are expected to be collected over 18 months. The Institutional Review Board (IRB) is a board at each institution in the United States that reviews and monitors research involving human subjects. IRB approval from the University of Pittsburgh was obtained on 30 November 2021 (STUDY21080150), from the University of California San Diego's Human Research Protection Program IRB on 14 July 2022 (802047), and from the Boston Children's Hospital IRB on 25 October 2022 (P00040987). Full study results are planned to be published within 2 years of initial study recruitment (October 2024). Dissemination of findings will occur in peer-reviewed journals, professional conferences and through reports to participating entities and stakeholders. TRIAL REGISTRATION NUMBER: NCT05159713; ClinicalTrials.gov.

Odds of COVID-19-associated asthma exacerbations in children higher during Omicron wave.

BACKGROUND: We aimed to determine the association of COVID-19 variant wave with asthma exacerbations in children with asthma. METHODS: We conducted a retrospective cross-sectional study of children in the Western Pennsylvania COVID-19 Registry (WPACR). We extracted data for all children in the WPACR with asthma and compared their acute clinical presentation and outcomes during the Pre-Delta (7/1/20-6/30/21), Delta (8/1/21-12/14/21), and Omicron (12/15/21-8/30/22) waves. We conducted multivariable logistic regression analyses of SARS-CoV-2-associated asthma exacerbations, adjusting for characteristics that have been associated with COVID-19 outcomes in prior studies. RESULTS: Among 573 children with asthma in the WPACR during the study period, the proportion of children with COVID-19 who had an asthma exacerbation was higher during the Omicron wave than during the prior two variant waves (40.2% vs. 22.6% vs. 26.2%, p = 0.002; unadjusted OR = 2.12 [95% confidence interval (CI) = 1.39-3.22], p < 0.001). In our multivariable regression models, the odds of an asthma exacerbation were 2.8 times higher during the Omicron wave than during prior waves (adjusted OR = 2.80 [95% CI = 1.70-4.61]). Results were similar after additionally adjusting for asthma severity but were no longer significant after additionally adjusting for poor asthma control. CONCLUSION: The proportion of children with asthma experiencing an asthma exacerbation during SARS-CoV-2 infection was higher during Omicron than prior variant waves, adding to the body of evidence that COVID-19-associated respiratory symptoms vary by variant. These findings provide additional support for vaccination and prevention.

The Impact of SARS-CoV-2 Infection on Symptom Control and Lung Function in Children with Asthma.

Rationale: Little is known about the long-term impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on children with asthma. Objectives: To determine whether SARS-CoV-2 infection affects symptom control and lung function in children with asthma. Methods: Using data from clinical registries and the electronic health record, we conducted a prospective case-control study of children with asthma aged 6-21 years who had (cases) or did not have (control subjects) SARS-CoV-2 infection, comparing baseline and follow-up asthma symptom control and spirometry within an ∼18-month time frame and, for cases, within 18 months of acute coronavirus disease (COVID-19). Results: A total of 171 cases had baseline and follow-up asthma symptom data, and 114 cases had baseline and follow-up spirometry measurements. There were no significant differences in asthma symptom control (P = 0.50), forced expiratory volume in 1 second (P = 0.47), forced vital capacity (P = 0.43), forced expiratory volume in 1 second/forced vital capacity (P = 0.43), or forced expiratory flow, midexpiratory phase (P = 0.62), after SARS-CoV-2 infection. Compared with control subjects (113 with symptom data and 237 with spirometry data), there were no significant differences in follow-up asthma symptom control or lung function. A similar proportion of cases and control subjects had poorer asthma symptom control (17.5% vs. 9.7%; P = 0.07) or worse lung function (29.0% vs. 32.5%; P = 0.50) at follow-up. Patients whose asthma control worsened after COVID-19 had a shorter time to follow-up (3.5 [1.5-7.5] vs. 6.1 [3.1-9.8] mo; P = 0.007) and were more likely to have presented with an asthma exacerbation during COVID-19 (46% vs. 26%; P = 0.04) than those without worse control. Conclusions: We found no significant differences in asthma symptom control or lung function in youth with asthma up to 18 months after acute COVID-19, suggesting that COVID-19 does not affect long-term asthma severity or control in the pediatric population.

AMPK activator-treated human cardiac spheres enhance maturation and enable pathological modeling.

BACKGROUND: Cardiac pathological outcome of metabolic remodeling is difficult to model using cardiomyocytes derived from human-induced pluripotent stem cells (hiPSC-CMs) due to low metabolic maturation. METHODS: hiPSC-CM spheres were treated with AMP-activated protein kinase (AMPK) activators and examined for hiPSC-CM maturation features, molecular changes and the response to pathological stimuli. RESULTS: Treatment of hiPSC-CMs with AMPK activators increased ATP content, mitochondrial membrane potential and content, mitochondrial DNA, mitochondrial function and fatty acid uptake, indicating increased metabolic maturation. Conversely, the knockdown of AMPK inhibited mitochondrial maturation of hiPSC-CMs. In addition, AMPK activator-treated hiPSC-CMs had improved structural development and functional features-including enhanced Ca2+ transient kinetics and increased contraction. Transcriptomic, proteomic and metabolomic profiling identified differential levels of expression of genes, proteins and metabolites associated with a molecular signature of mature cardiomyocytes in AMPK activator-treated hiPSC-CMs. In response to pathological stimuli, AMPK activator-treated hiPSC-CMs had increased glycolysis, and other pathological outcomes compared to untreated cells. CONCLUSION: AMPK activator-treated cardiac spheres could serve as a valuable model to gain novel insights into cardiac diseases.

An enhancer-based gene-therapy strategy for spatiotemporal control of cargoes during tissue repair.

The efficacy and safety of gene-therapy strategies for indications like tissue damage hinge on precision; yet, current methods afford little spatial or temporal control of payload delivery. Here, we find that tissue-regeneration enhancer elements (TREEs) isolated from zebrafish can direct targeted, injury-associated gene expression from viral DNA vectors delivered systemically in small and large adult mammalian species. When employed in combination with CRISPR-based epigenome editing tools in mice, zebrafish TREEs stimulated or repressed the expression of endogenous genes after ischemic myocardial infarction. Intravenously delivered recombinant AAV vectors designed with a TREE to direct a constitutively active YAP factor boosted indicators of cardiac regeneration in mice and improved the function of the injured heart. Our findings establish the application of contextual enhancer elements as a potential therapeutic platform for spatiotemporally controlled tissue regeneration in mammals.