Using induced pluripotent stem cells for drug discovery in arrhythmias.

INTRODUCTION: Arrhythmias are disturbances in the normal rhythm of the heart and account for significant cardiovascular morbidity and mortality worldwide. Historically, preclinical research has been anchored in animal models, though physiological differences between these models and humans have limited their clinical translation. The discovery of human induced pluripotent stem cells (iPSC) and subsequent differentiation into cardiomyocyte has led to the development of new in vitro models of arrhythmias with the hope of a new pathway for both exploration of pathogenic variants and novel therapeutic discovery. AREAS COVERED: The authors describe the latest two-dimensional in vitro models of arrhythmias, several examples of the use of these models in drug development, and the role of gene editing when modeling diseases. They conclude by discussing the use of three-dimensional models in the study of arrythmias and the integration of computational technologies and machine learning with experimental technologies. EXPERT OPINION: Human iPSC-derived cardiomyocytes models have significant potential to augment disease modeling, drug discovery, and toxicity studies in preclinical development. While there is initial success with modeling arrhythmias, the field is still in its nascency and requires advances in maturation, cellular diversity, and readouts to emulate arrhythmias more accurately.

Emergent Management of Central Nervous System Demyelinating Disorders.

OBJECTIVE: This article reviews the various conditions that can present with acute and severe central nervous system demyelination, the broad differential diagnosis of these conditions, the most appropriate diagnostic workup, and the acute treatment regimens to be administered to help achieve the best possible patient outcomes. LATEST DEVELOPMENTS: The discovery of anti-aquaporin 4 (AQP4) antibodies and anti-myelin oligodendrocyte glycoprotein (MOG) antibodies in the past two decades has revolutionized our understanding of acute demyelinating disorders, their evaluation, and their management. ESSENTIAL POINTS: Demyelinating disorders comprise a large category of neurologic disorders seen by practicing neurologists. In the majority of cases, patients with these conditions do not require care in an intensive care unit. However, certain disorders may cause severe demyelination that necessitates intensive care unit admission because of numerous simultaneous multifocal lesions, tumefactive lesions, or lesions in certain brain locations that lead to acute severe neurologic dysfunction. Intensive care may be necessary for the management and prevention of complications for patients who have severely altered mental status, rapidly progressive neurologic worsening, elevated intracranial pressure, severe cerebral edema, status epilepticus, or respiratory failure.

Protocol to study CCT-mediated folding of Gß5 by single-particle cryo-EM.

The chaperonin CCT mediates folding of many cytosolic proteins, including G protein ß subunits (Gßs). Here, we present a protocol for isolating Gß5 bound to CCT and its co-chaperone PhLP1 and determining the CCT-mediated folding trajectory of Gß5 using single-particle cryoelectron microscopy (cryo-EM) techniques. We describe steps for purifying CCT-Gß5-PhLP1 from human cells, stabilizing the closed CCT conformation, preparing and imaging cryo-EM specimens, and processing data to recover multiple Gß5 folding intermediates. This protocol permits visualization of protein folding by CCT. For complete details on the use and execution of this protocol, please refer to Sass et al.1.

Electrophysiological markers of vestibular-mediated self-motion perception - A pilot study.

Peripheral vestibular activation results in multi-level responses, from brainstem-mediated reflexes (e.g. vestibular ocular reflex - VOR) to perception of self-motion. While VOR responses indicate preserved vestibular peripheral and brainstem functioning, there are no automated measures of vestibular perception of self-motion - important since some patients with brain disconnection syndromes manifest a vestibular agnosia (intact VOR but impaired self-motion perception). Electroencephalography ('EEG') - may provide a surrogate marker of vestibular perception of self-motion. A related objective is obtaining an EEG marker of vestibular sensory signal processing, distinct from vestibular-motion perception. We performed a pilot study comparing EEG responses in the dark when healthy participants sat in a vibrationless computer-controlled motorised rotating chair moving at near threshold of self-motion perception, versus a second situation in which subjects sat in the chair at rest in the dark who could be induced (or not) into falsely perceiving self-motion. In both conditions subjects could perceive self-motion perception, but in the second there was no bottom-up reflex-brainstem activation. Time-frequency analyses showed: (i) alpha frequency band activity is linked to vestibular sensory-signal activation; and (ii) theta band activity is a marker of vestibular-mediated self-motion perception. Consistent with emerging animal data, our findings support the role of theta activity in the processing of self-motion perception.

National policies to limit food marketing and competitive food sales in schools: a global scoping review.

School food environments contribute to children's nutritional intake and overall health. As such, the World Health Organization and other public health organizations encourage policies that restrict children's access and exposure to foods and beverages that do not build health in and around schools. This global scoping review explores the presence and characteristics of policies that restrict competitive food sales and marketing for unhealthy foods across 193 countries using evidence from policy databases, grey literature, peer-reviewed literature, and primary policy documents. Policies were included if they were nationally mandated and regulated marketing and/or competitive foods in the school environments. Worldwide, only 28% of countries were found to have any national-level policy restricting food marketing or competitive food sales in schools: 16% of countries restrict marketing, 25% restrict competitive foods, and 12% restrict both. Over half of policies were found in high-income countries. No low-income countries had either policy type. Eight marketing policies (27%) and 14 competitive foods policies (29%) lacked explicit guidelines for either policy monitoring or enforcement. Future research is needed to assess the prevalence of policies aimed at improving other key aspects of the school food environment, such as dietary quality of school meals or food procurement, as well as assess implementation and efficacy of existing policies.

Primary closure of fasciotomies has a reduced complication rate following compartment syndrome in the paediatric population.

PURPOSE: Currently no guidance exists within the literature regarding diagnostic criteria or the long-term outcomes for paediatric patients with acute compartment syndrome (ACS). We conducted a retrospective cohort study reviewing all cases of paediatric ACS managed at a single tertiary referral centre with the aim of characterising the factors responsible for the eventual outcomes. METHODS: The patient cohort was identified retrospectively by interrogating the hospital coding system for all paediatric patients between January 2014 and November 2022. The electronic emergency department, inpatient and operative notes as well as clinic letters for each patient were reviewed and data collected regarding presentation, associated injuries, management and subsequent complications plus length of follow-up. The data was analysed to determine if differences in presentation or management affected long term outcome. RESULTS: The final cohort consisted of 34 patients with a mean age of ten years at the time of presentation. The mean time from presentation to fasciotomy was 27.6 h (range 3.0 - 66.6). There was an overall complication rate of 37.5% with a mean follow-up period of 21 months. Patients who had direct closure of their fasciotomy wounds had a significantly lower complications rate and fewer operations compared to those who healed via other wound coverage methods or secondary intention (p < 0.05). CONCLUSIONS: Significantly higher complication rates were observed in patients who were unable to have direct wound closure following emergency fasciotomy. This information may be utilised to rationalise long term treatment plans and in counselling of patients and parents.

Cell adhesion molecule CD44 is dispensable for reactive astrocyte activation during prion disease.

Prion diseases are fatal, infectious, neurodegenerative disorders resulting from accumulation of misfolded cellular prion protein in the brain. Early pathological changes during CNS prion disease also include reactive astrocyte activation with increased CD44 expression, microgliosis, as well as loss of dendritic spines and synapses. CD44 is a multifunctional cell surface adhesion and signalling molecule which is considered to play roles in astrocyte morphology and the maintenance of dendritic spine integrity and synaptic plasticity. However, the role of CD44 in prion disease was unknown. Here we used mice deficient in CD44 to determine the role of CD44 during prion disease. We show that CD44-deficient mice displayed no difference in their response to CNS prion infection when compared to wild type mice. Furthermore, the reactive astrocyte activation and microgliosis that accompanies CNS prion infection was unimpaired in the absence of CD44. Together, our data show that although CD44 expression is upregulated in reactive astrocytes during CNS prion disease, it is dispensable for astrocyte and microglial activation and the development of prion neuropathogenesis.

Evidence for neurobehavioral risk phenotypes at birth.

Observations of newborn behavior provide clinicians and researchers with a first description of the neurobehavioral organization of the newborn that is largely independent of the postnatal environment. The Neonatal Network Neurobehavioral Scale (NNNS) was developed in 2004 to evaluate how prenatal exposure to substances such as cocaine is related to neurobehavioral outcomes. There are now 156 empirical articles published using the NNNS, which we review and summarize. Z-scores from published studies using the NNNS were compiled and aggregated supporting the replicability of three newborn neurobehavioral phenotypes: one typical and two that are predictive of later cognitive and behavioral delay; hyper- and hypo-dysregulated newborns. These phenotypes emerged from independent samples and research groups and were identified in a variety of populations, including infants with prenatal substance exposure, preterm infants, and healthy term infants. Our findings show that newborn neurobehavior can be measured in a reliable and valid manner and that certain behavioral phenotypes, identifiable at birth, can predict neurodevelopmental challenges. These findings have important clinical utility. Intervening early with infants exhibiting these risk phenotypes may prevent later neurodevelopmental delay. IMPACT: We reviewed all empirical studies published using the Neonatal Network Neurobehavioral Scale and found evidence for two replicable stress phenotypes that predict later behavioral outcomes. This study highlights the utility of the Neonatal Network Neurobehavioral Scale for early identification of newborn neurodevelopmental risk phenotypes. Early identification of neurodevelopmental risk, when neuroplasticity is high, may ultimately reduce the burden of subsequent neurobehavioral problems through early intervention.

Predicted impact of banning nonessential, energy-dense food and beverages in schools in Mexico: A microsimulation study.

BACKGROUND: Childhood obesity is a growing concern worldwide. School-based interventions have been proposed as effective means to improve nutritional knowledge and prevent obesity. In 2023, Mexico approved a reform to the General Education Law to strengthen the ban of sales and advertising of nonessential energy-dense food and beverages (NEDFBs) in schools and surroundings. We aimed to predict the expected one-year change in total caloric intake and obesity prevalence by introducing the ban of NEDFBs sales in schools, among school-aged children and adolescents (6 to 17 years old) in Mexico. METHODS AND FINDINGS: We used age-specific equations to predict baseline fat-free mass (FFM) and fat mass (FM) and then estimated total energy intake (TEI) per day. The TEI after the intervention was estimated under 4 scenarios: (1) using national data to inform the intervention effect; (2) varying law compliance; (3) using meta-analytic data to inform the intervention effect size on calories; and (4) using national data to inform the intervention effect by sex and socioeconomic status (SES). We used Hall's microsimulation model to estimate the potential impact on body weight and obesity prevalence of children and adolescents 1 year after implementing the intervention in Mexican schools. We found that children could reduce their daily energy intake by 33 kcal/day/person (uncertainty interval, UI, [25, 42] kcal/day/person), reducing on average 0.8 kg/person (UI [0.6, 1.0] kg/person) and 1.5 percentage points (pp) in obesity (UI [1.1, 1.9] pp) 1 year after implementing the law. We showed that compliance will be key to the success of this intervention: considering a 50% compliance the intervention effect could reduce 0.4 kg/person (UI [0.3, 0.5] kg/person). Our sensitivity analysis showed that the ban could reduce body weight by 1.3 kg/person (UI [0.8, 1.8] kg/person) and up to 5.4 kg/person (UI [3.4, 7.5] kg/person) in the best-case scenario. Study limitations include assuming that obesity and the contribution of NEDFBs consumed at school remain constant over time, assuming full compliance, and not considering the potential effect of banning NEDFBs in stores near schools. CONCLUSIONS: Even in the most conservative scenario, banning sales of NEDFBs in schools is expected to significantly reduce obesity, but achieving high compliance will be key to its success. WHY WAS THIS STUDY DONE?: - School-based interventions have been recognized as effective means to improve nutritional knowledge and prevent obesity-related diseases.- In December 2023, the Chamber of Representatives of Mexico approved an amendment that strengthens and updates the General Education Law (Article 75) and nutritional guidelines to ban the sales and advertising of nonessential energy-dense food and beverages (NEDFBs) in schools. WHAT DID THE RESEARCHERS DO AND FIND?: - We used age-specific equations to predict baseline fat-free mass (FFM) and fat mass (FM) and total energy intake (TEI) per day.- We used microsimulation modeling to predict body weight and obesity prevalence of children and adolescents 1 year after implementing the intervention in Mexican schools.- Our modeling study suggests that an important impact on obesity prevalence can be expected if the law is implemented and enforced as intended. WHAT DO THESE FINDINGS MEAN?: - If successful, this law could serve as an example beyond Mexico on how to achieve changes in body weight through school food regulation.- An important limitation of our main scenario is that we assumed full compliance of schools with the law, yet lower compliance will reduce its impact. We also did not consider historical trends on obesity or NEDFBs consumed in schools during our 1 year simulation, and we considered only the ban impact inside schools, excluding effects near and outside schools.

Treating benign paroxysmal positional vertigo in acute traumatic brain injury: a prospective, randomised clinical trial assessing safety, feasibility, and efficacy.

Background: Benign paroxysmal positional vertigo (BPPV) affects approximately half of acute, moderate-severe traumatic brain injury (TBI) patients. To date, there have been no rigorous studies of BPPV assessment or treatment in this cohort. We aimed to determine the safety, practicability, and efficacy of therapist-led BPPV management in acute TBI and the feasibility of a larger effectiveness trial. Methods: This was a multi-centre, three-arm, parallel-groups, randomised, feasibility trial. Recruitment was via convenience sampling. The main inclusion criteria were age over 18 years and a confirmed, non-penetrating, acute TBI. BPPV-positive patients were randomly allocated to one of three interventions (repositioning manoeuvres, Brandt-Daroff exercises or advice) using minimisation criteria. Outcome assessors were blinded to the intervention. Results: Of 2014 patients screened for inclusion, 180 were assessed for BPPV. Of those assessed, 34% (62/180) had BPPV, and 58 patients received an intervention. Therapist-led interventions were delivered safely and accurately according to intervention monitoring criteria. Resolution of BPPV was observed in 35/58 (60%) patients. The resolution rate was highest following repositioning manoeuvres (78%), followed by the advice (53%) and Brandt-Daroff interventions (42%). 10 patients experienced recurrence. This was observed more frequently in those with skull fractures and bilateral or mixed BPPV. Conclusions: Overall, the results provide strong evidence for the feasibility of a future trial. Therapist-led management of BPPV in acute TBI was safe and practicable. Repositioning manoeuvres seemingly yielded a superior treatment effect. However, given the high recurrence rate of post-traumatic BPPV, the optimal time to treat according to patients' specific recurrence risk requires further investigation. Trial registration: ISRCTN91943864, https://doi.org/10.1186/ISRCTN91943864.

Illusions of Self-Motion during Magnetic Resonance-Guided Focused Ultrasound Thalamotomy for Tremor.

OBJECTIVE: Brain networks mediating vestibular perception of self-motion overlap with those mediating balance. A systematic mapping of vestibular perceptual pathways in the thalamus may reveal new brain modulation targets for improving balance in neurological conditions. METHODS: Here, we systematically report how magnetic resonance-guided focused ultrasound surgery of the nucleus ventralis intermedius of the thalamus commonly evokes transient patient-reported illusions of self-motion. In 46 consecutive patients, we linked the descriptions of self-motion to sonication power and 3-dimensional (3D) coordinates of sonication targets. Target coordinates were normalized using a standard atlas, and a 3D model of the nucleus ventralis intermedius and adjacent structures was created to link sonication target to the illusion. RESULTS: A total of 63% of patients reported illusions of self-motion, which were more likely with increased sonication power and with targets located more inferiorly along the rostrocaudal axis. Higher power and more inferiorly targeted sonications increased the likelihood of experiencing illusions of self-motion by 4 and 2 times, respectively (odds ratios = 4.03 for power, 2.098 for location). INTERPRETATION: The phenomenon of magnetic vestibular stimulation is the most plausible explanation for these illusions of self-motion. Temporary unilateral modulation of vestibular pathways (via magnetic resonance-guided focused ultrasound) unveils the central adaptation to the magnetic field-induced peripheral vestibular bias, leading to an explicable illusion of motion. Consequently, systematic mapping of vestibular perceptual pathways via magnetic resonance-guided focused ultrasound may reveal new intracerebral targets for improving balance in neurological conditions. ANN NEUROL 2024;96:121-132.

Neonatal neurobehavior associated with developmental changes from age 2 to 3 in very preterm infants.

OBJECTIVE: Understand how high-risk infants' development changes over time. Examine whether NICU Network Neurobehavioral Scale (NNNS) profiles are associated with decrements in developmental outcomes between ages 2 and 3 years in infants born very preterm. STUDY DESIGN: The Neonatal Outcomes for Very preterm Infants (NOVI) cohort is a multisite prospective study of 704 preterm infants born <30 weeks' gestation across nine university and VON affiliated NICUs. Data included infant neurobehavior measured by NNNS profiles at NICU discharge and the Bayley Scales of Infant and Toddler Development (BSID-III) at ages 2 and 3 years. Generalized estimating equations tested associations between NNNS profiles and BSID-III composite score changes between ages 2 and 3 years. RESULTS: The final study sample included 433 infants with mean gestational age of 27 weeks at birth. Infants with dysregulated NNNS profiles were more likely to have decreases in BSID-III Cognitive (OR = 2.66) and Language scores (OR = 2.53) from age 2 to 3 years compared to infants with more well-regulated neurobehavioral NNNS profiles. Further, infants with more well-regulated NNNS profiles were more likely to have increases in BSID-III Cognitive scores (OR = 2.03), rather than no change, compared to infants with dysregulated NNNS profiles. CONCLUSIONS AND RELEVANCE: Prior to NICU discharge, NNNS neurobehavioral profiles identified infants at increased risk for developing later language and cognitive challenges. Findings suggests that neonatal neurobehavior provides a unique, clinically significant contribution to the evaluation of very preterm infants to inform treatment planning for the most vulnerable.

BeatProfiler: Multimodal In Vitro Analysis of Cardiac Function Enables Machine Learning Classification of Diseases and Drugs.

Goal: Contractile response and calcium handling are central to understanding cardiac function and physiology, yet existing methods of analysis to quantify these metrics are often time-consuming, prone to mistakes, or require specialized equipment/license. We developed BeatProfiler, a suite of cardiac analysis tools designed to quantify contractile function, calcium handling, and force generation for multiple in vitro cardiac models and apply downstream machine learning methods for deep phenotyping and classification. Methods: We first validate BeatProfiler's accuracy, robustness, and speed by benchmarking against existing tools with a fixed dataset. We further confirm its ability to robustly characterize disease and dose-dependent drug response. We then demonstrate that the data acquired by our automatic acquisition pipeline can be further harnessed for machine learning (ML) analysis to phenotype a disease model of restrictive cardiomyopathy and profile cardioactive drug functional response. To accurately classify between these biological signals, we apply feature-based ML and deep learning models (temporal convolutional-bidirectional long short-term memory model or TCN-BiLSTM). Results: Benchmarking against existing tools revealed that BeatProfiler detected and analyzed contraction and calcium signals better than existing tools through improved sensitivity in low signal data, reduction in false positives, and analysis speed increase by 7 to 50-fold. Of signals accurately detected by published methods (PMs), BeatProfiler's extracted features showed high correlations to PMs, confirming that it is reliable and consistent with PMs. The features extracted by BeatProfiler classified restrictive cardiomyopathy cardiomyocytes from isogenic healthy controls with 98% accuracy and identified relax90 as a top distinguishing feature in congruence with previous findings. We also show that our TCN-BiLSTM model was able to classify drug-free control and 4 cardiac drugs with different mechanisms of action at 96% accuracy. We further apply Grad-CAM on our convolution-based models to identify signature regions of perturbations by these drugs in calcium signals. Conclusions: We anticipate that the capabilities of BeatProfiler will help advance in vitro studies in cardiac biology through rapid phenotyping, revealing mechanisms underlying cardiac health and disease, and enabling objective classification of cardiac disease and responses to drugs.

The criminalization of women with postpartum psychosis: "a call for action" for judicial change.

PURPOSE: To prevent the incarceration and influence outcomes when criminal culpability is linked to postpartum psychosis. METHODS: Infanticide, neonaticide and filicide are most often linked with postpartum psychosis, which affects 1-2 women per 1,000 births or 4,000 women each year in the United States. Multiple genetic, hormonal and psychosocial factors surrounding childbirth result in a 1 to 4% risk of infanticide in women with postpartum psychosis. The authors seek to increase awareness of postpartum psychosis and postpartum depression in state legislatures. Others are working to have it recognized in the Diagnostic and Statistical Manual of Mental Disorders (DSM) as a specific illness. Specific postpartum legislation for those charged with crimes related to maternal mental illness is necessary. RESULTS: In Illinois, the very first criminal law in the nation recognizing the pernicious effects of this illness went into effect in 2018. The authors and others are attempting to cause similar or broader legislation to be brought in other states. Several women have been released from extended incarceration utilizing this law. CONCLUSIONS: This temporary mental illness can lead to tragic outcomes when hospitalization and crisis intervention is delayed or the illness is misdiagnosed. The legal/judicial system has not utilized the growing body of scientific developments that medical researchers have discovered in recent decades. The lack of a unique diagnostic classification in the DSM and the lack of postpartum criminal laws, lead to mentally ill mothers in the U.S. receiving excessively harsh sentences when prosecuted, evidenced both in trial and sentencing.

Developmental characteristics and accuracy of autism screening among two-year-old toddlers in the ECHO program.

BACKGROUND: The Modified Checklist for Autism in Toddlers (M-CHAT) is a common pediatric screening tool with mixed accuracy findings. Prior evidence supports M-CHAT screening for developmental concerns, especially in toddlers born preterm. This study examined M-CHAT accuracy in a large, nationwide sample. METHODS: 3393 participants from the Environmental influences on Child Health Outcomes (ECHO) program were included. Harmonized M-CHAT (M-CHAT-H) results were compared with parent-reported autism diagnosis and autism-related characteristics to assess accuracy for term and preterm children, together and separately. Generalized estimating equations, clustering for ECHO cohort and controlling for demographic covariates, were used to examine associations between developmental and behavioral characteristics with M-CHAT-H accuracy. RESULTS: Sensitivity of the M-CHAT-H ranged from 36 to 60%; specificity ranged from 88 to 99%. Positive M-CHAT-H was associated with more developmental delays and behavior problems. Children with severe motor delays and more autism-related problems were more likely to have a false-negative M-CHAT-H. Children with fewer behavior problems and fewer autism-related concerns were more likely to have a false-positive screen. CONCLUSION: The M-CHAT-H accurately detects children at low risk for autism and children at increased risk with moderate accuracy. These findings support use of the M-CHAT-H in assessing autism risk and developmental and behavioral concerns in children. IMPACT: Previous literature regarding accuracy of the Modified Checklist for Autism in Toddlers (M-CHAT) is mixed but this study provides evidence that the M-CHAT performs well in detecting children at low risk for autism and consistently detects children with developmental delays and behavioral problems. The M-CHAT moderately detects children at increased risk for autism and remains a useful screening tool. This study examines M-CHAT accuracy in a large-scale, nationwide sample, examining associations between screening accuracy and developmental outcomes. These findings impact pediatric screening for autism, supporting continued use of the M-CHAT while further elucidating the factors associated with inaccurate screens.

Epigenetic associations in HPA axis genes related to bronchopulmonary dysplasia and antenatal steroids.

BACKGROUND: Bronchopulmonary dysplasia (BPD), a common morbidity among very preterm infants, is associated with chronic disease and neurodevelopmental impairments. A hypothesized mechanism for these outcomes lies in altered glucocorticoid (GC) activity. We hypothesized that BPD and its treatments may result in epigenetic differences in the hypothalamic-pituitary-adrenal (HPA) axis, which is modulated by GC, and could be ascertained using an established GC risk score and DNA methylation (DNAm) of HPA axis genes. METHODS: DNAm was quantified from buccal tissue (ECHO-NOVI) and from neonatal blood spots (ELGAN ECHO) via the EPIC microarray. Prenatal maternal characteristics, pregnancy complication, and neonatal medical complication data were collected from medical record review and maternal interviews. RESULTS: The GC score was not associated with steroid exposure or BPD. However, six HPA genes involved in stress response regulation demonstrated differential methylation with antenatal steroid exposure; two CpGs within FKBP5 and POMC were differentially methylated with BPD severity. These findings were sex-specific in both cohorts; males had greater magnitude of differential methylation within these genes. CONCLUSIONS: These findings suggest that BPD severity and antenatal steroids are associated with DNAm at some HPA genes in very preterm infants and the effects appear to be sex-, tissue-, and age-specific. IMPACT: This study addresses bronchopulmonary dysplasia (BPD), an important health outcome among preterm neonates, and interrogates a commonly studied pathway, the hypothalamic-pituitary-adrenal (HPA) axis. The combination of BPD, the HPA axis, and epigenetic markers has not been previously reported. In this study, we found that BPD itself was not associated with epigenetic responses in the HPA axis in infants born very preterm; however, antenatal treatment with steroids was associated with epigenetic responses.