An analog-AI chip for energy-efficient speech recognition and transcription.

Models of artificial intelligence (AI) that have billions of parameters can achieve high accuracy across a range of tasks1,2, but they exacerbate the poor energy efficiency of conventional general-purpose processors, such as graphics processing units or central processing units. Analog in-memory computing (analog-AI)3-7 can provide better energy efficiency by performing matrix-vector multiplications in parallel on 'memory tiles'. However, analog-AI has yet to demonstrate software-equivalent (SWeq) accuracy on models that require many such tiles and efficient communication of neural-network activations between the tiles. Here we present an analog-AI chip that combines 35 million phase-change memory devices across 34 tiles, massively parallel inter-tile communication and analog, low-power peripheral circuitry that can achieve up to 12.4 tera-operations per second per watt (TOPS/W) chip-sustained performance. We demonstrate fully end-to-end SWeq accuracy for a small keyword-spotting network and near-SWeq accuracy on the much larger MLPerf8 recurrent neural-network transducer (RNNT), with more than 45 million weights mapped onto more than 140 million phase-change memory devices across five chips.

Next-Generation Multitarget Stool DNA Test for Colorectal Cancer Screening.

BACKGROUND: A next-generation multitarget stool DNA test, including assessments of DNA molecular markers and hemoglobin level, was developed to improve the performance of colorectal cancer screening, primarily with regard to specificity. METHODS: In a prospective study, we evaluated a next-generation multitarget stool DNA test in asymptomatic adults 40 years of age or older who were undergoing screening colonoscopy. The primary outcomes were sensitivity of the test for colorectal cancer and specificity for advanced neoplasia (colorectal cancer or advanced precancerous lesions). Advanced precancerous lesions included one or more adenomas or sessile serrated lesions measuring at least 1 cm in the longest dimension, lesions with villous histologic features, and high-grade dysplasia. Secondary objectives included the quantification of sensitivity for advanced precancerous lesions and specificity for nonneoplastic findings or negative colonoscopy and comparison of sensitivities for colorectal cancer and advanced precancerous lesions between the multitarget stool DNA test and a commercially available fecal immunochemical test (FIT). RESULTS: Of 20,176 participants, 98 had colorectal cancer, 2144 had advanced precancerous lesions, 6973 had nonadvanced adenomas, and 10,961 had nonneoplastic findings or negative colonoscopy. With the next-generation test, sensitivity for colorectal cancer was 93.9% (95% confidence interval [CI], 87.1 to 97.7), and specificity for advanced neoplasia was 90.6% (95% CI, 90.1 to 91.0). Sensitivity for advanced precancerous lesions was 43.4% (95% CI, 41.3 to 45.6), and specificity for nonneoplastic findings or negative colonoscopy was 92.7% (95% CI, 92.2 to 93.1). With the FIT, sensitivity was 67.3% (95% CI, 57.1 to 76.5) for colorectal cancer and 23.3% (95% CI, 21.5 to 25.2) for advanced precancerous lesions; specificity was 94.8% (95% CI, 94.4 to 95.1) for advanced neoplasia and 95.7% (95% CI, 95.3 to 96.1) for nonneoplastic findings or negative colonoscopy. As compared with FIT, the next-generation test had superior sensitivity for colorectal cancer (P<0.001) and for advanced precancerous lesions (P<0.001) but had lower specificity for advanced neoplasia (P<0.001). No adverse events occurred. CONCLUSIONS: The next-generation multitarget stool DNA test showed higher sensitivity for colorectal cancer and advanced precancerous lesions than FIT but also showed lower specificity. (Funded by Exact Sciences; BLUE-C ClinicalTrials.gov number, NCT04144738.).

A conserved protein tyrosine phosphatase, PTPN-22, functions in diverse developmental processes in C. elegans.

Protein tyrosine phosphatases non-receptor type (PTPNs) have been studied extensively in the context of the adaptive immune system; however, their roles beyond immunoregulation are less well explored. Here we identify novel functions for the conserved C. elegans phosphatase PTPN-22, establishing its role in nematode molting, cell adhesion, and cytoskeletal regulation. Through a non-biased genetic screen, we found that loss of PTPN-22 phosphatase activity suppressed molting defects caused by loss-of-function mutations in the conserved NIMA-related kinases NEKL-2 (human NEK8/NEK9) and NEKL-3 (human NEK6/NEK7), which act at the interface of membrane trafficking and actin regulation. To better understand the functions of PTPN-22, we carried out proximity labeling studies to identify candidate interactors of PTPN-22 during development. Through this approach we identified the CDC42 guanine-nucleotide exchange factor DNBP-1 (human DNMBP) as an in vivo partner of PTPN-22. Consistent with this interaction, loss of DNBP-1 also suppressed nekl-associated molting defects. Genetic analysis, co-localization studies, and proximity labeling revealed roles for PTPN-22 in several epidermal adhesion complexes, including C. elegans hemidesmosomes, suggesting that PTPN-22 plays a broad role in maintaining the structural integrity of tissues. Localization and proximity labeling also implicated PTPN-22 in functions connected to nucleocytoplasmic transport and mRNA regulation, particularly within the germline, as nearly one-third of proteins identified by PTPN-22 proximity labeling are known P granule components. Collectively, these studies highlight the utility of combined genetic and proteomic approaches for identifying novel gene functions.

Cell-type-specific enhancement of deviance detection by synaptic zinc in the mouse auditory cortex.

Stimulus-specific adaptation is a hallmark of sensory processing in which a repeated stimulus results in diminished successive neuronal responses, but a deviant stimulus will still elicit robust responses from the same neurons. Recent work has established that synaptically released zinc is an endogenous mechanism that shapes neuronal responses to sounds in the auditory cortex. Here, to understand the contributions of synaptic zinc to deviance detection of specific neurons, we performed wide-field and 2-photon calcium imaging of multiple classes of cortical neurons. We find that intratelencephalic (IT) neurons in both layers 2/3 and 5 as well as corticocollicular neurons in layer 5 all demonstrate deviance detection; however, we find a specific enhancement of deviance detection in corticocollicular neurons that arises from ZnT3-dependent synaptic zinc in layer 2/3 IT neurons. Genetic deletion of ZnT3 from layer 2/3 IT neurons removes the enhancing effects of synaptic zinc on corticocollicular neuron deviance detection and results in poorer acuity of detecting deviant sounds by behaving mice.

Evidence for heterothermic endothermy and reptile-like eggshell mineralization in Troodon, a non-avian maniraptoran theropod.

The dinosaur-bird transition involved several anatomical, biomechanical, and physiological modifications of the theropod bauplan. Non-avian maniraptoran theropods, such as Troodon, are key to better understand changes in thermophysiology and reproduction occurring during this transition. Here, we applied dual clumped isotope (Δ47 and Δ48) thermometry, a technique that resolves mineralization temperature and other nonthermal information recorded in carbonates, to eggshells from Troodon, modern reptiles, and modern birds. Troodon eggshells show variable temperatures, namely 42 and 29 ± 2 °C, supporting the hypothesis of an endothermic thermophysiology with a heterothermic strategy for this extinct taxon. Dual clumped isotope data also reveal physiological differences in the reproductive systems between Troodon, reptiles, and birds. Troodon and modern reptiles mineralize their eggshells indistinguishable from dual clumped isotope equilibrium, while birds precipitate eggshells characterized by a positive disequilibrium offset in Δ48. Analyses of inorganic calcites suggest that the observed disequilibrium pattern in birds is linked to an amorphous calcium carbonate (ACC) precursor, a carbonate phase known to accelerate eggshell formation in birds. Lack of disequilibrium patterns in reptile and Troodon eggshells implies these vertebrates had not acquired the fast, ACC-based eggshell calcification process characteristic of birds. Observation that Troodon retained a slow reptile-like calcification suggests that it possessed two functional ovaries and was limited in the number of eggs it could produce; thus its large clutches would have been laid by several females. Dual clumped isotope analysis of eggshells of extinct vertebrates sheds light on physiological information otherwise inaccessible in the fossil record.

Trans-synaptic Association of Vesicular Zinc Transporter 3 and Shank3 Supports Synapse-Specific Dendritic Spine Structure and Function in the Mouse Auditory Cortex.

Shank3 is a synaptic scaffolding protein that assists in tethering and organizing structural proteins and glutamatergic receptors in the postsynaptic density of excitatory synapses. The localization of Shank3 at excitatory synapses and the formation of stable Shank3 complexes is regulated by the binding of zinc to the C-terminal sterile-alpha-motif (SAM) domain of Shank3. Mutations in the SAM domain of Shank3 result in altered synaptic function and morphology, and disruption of zinc in synapses that express Shank3 leads to a reduction of postsynaptic proteins important for synaptic structure and function. This suggests that zinc supports the localization of postsynaptic proteins via Shank3. Many regions of the brain are highly enriched with free zinc inside glutamatergic vesicles at presynaptic terminals. At these synapses, zinc transporter 3 (ZnT3) moves zinc into vesicles where it is co-released with glutamate. Alterations in ZnT3 are implicated in multiple neurodevelopmental disorders, and ZnT3 knock-out (KO) mice-which lack synaptic zinc-show behavioral deficits associated with autism spectrum disorder and schizophrenia. Here we show that male and female ZnT3 KO mice have smaller dendritic spines and miniature excitatory postsynaptic current amplitudes than wildtype (WT) mice in the auditory cortex. Additionally, spine size deficits in ZnT3 KO mice are restricted to synapses that express Shank3. In WT mice, synapses that express both Shank3 and ZnT3 have larger spines compared to synapses that express Shank3 but not ZnT3. Together these findings suggest a mechanism whereby presynaptic ZnT3-dependent zinc supports postsynaptic structure and function via Shank3 in a synapse-specific manner.

Chemical genetic analysis of enoxolone inhibition of C. difficile toxin production reveals adenine deaminase and ATP synthase as anti-virulence targets.

Toxins TcdA and TcdB are the main virulence factors of Clostridioides difficile, a leading cause of hospital-acquired diarrhea. Despite their importance, there is a significant knowledge gap of druggable targets for inhibiting toxin production. To address this, we screened non-antibiotic phytochemicals to identify potential chemical genetic probes to discover anti-virulence drug targets. This led to the identification of 18ß-glycyrrhetinic acid (enoxolone), a licorice metabolite, as an inhibitor of TcdA and TcdB biosynthesis. Using affinity-based proteomics, potential targets were identified as ATP synthase subunit alpha (AtpA) and adenine deaminase (Ade, which catalyzes conversion of adenine to hypoxanthine in the purine salvage pathway). To validate these targets, a multi-faceted approach was adopted. Gene silencing of ade and atpA inhibited toxin biosynthesis, while SPR and ITC molecular interaction analyses revealed direct binding of enoxolone to Ade. Metabolomics demonstrated enoxolone induced the accumulation of adenosine, while depleting hypoxanthine and ATP in C. difficile. Transcriptomics further revealed enoxolone dysregulated phosphate uptake genes, which correlated with reduced cellular phosphate levels. These findings suggest that enoxolone's cellular action is multi-targeted. Accordingly, supplementation with both hypoxanthine and triethyl phosphate (TEP), a phosphate source, was required to fully restore toxin production in the presence of enoxolone. In conclusion, through the characterization of enoxolone, we identified promising anti-virulence targets that interfere with nucleotide salvage and ATP synthesis, which may also block toxin biosynthesis.

Critical Assessment of Metagenome Interpretation: the second round of challenges.

Evaluating metagenomic software is key for optimizing metagenome interpretation and focus of the Initiative for the Critical Assessment of Metagenome Interpretation (CAMI). The CAMI II challenge engaged the community to assess methods on realistic and complex datasets with long- and short-read sequences, created computationally from around 1,700 new and known genomes, as well as 600 new plasmids and viruses. Here we analyze 5,002 results by 76 program versions. Substantial improvements were seen in assembly, some due to long-read data. Related strains still were challenging for assembly and genome recovery through binning, as was assembly quality for the latter. Profilers markedly matured, with taxon profilers and binners excelling at higher bacterial ranks, but underperforming for viruses and Archaea. Clinical pathogen detection results revealed a need to improve reproducibility. Runtime and memory usage analyses identified efficient programs, including top performers with other metrics. The results identify challenges and guide researchers in selecting methods for analyses.

ARGprofiler-a pipeline for large-scale analysis of antimicrobial resistance genes and their flanking regions in metagenomic datasets.

MOTIVATION: Analyzing metagenomic data can be highly valuable for understanding the function and distribution of antimicrobial resistance genes (ARGs). However, there is a need for standardized and reproducible workflows to ensure the comparability of studies, as the current options involve various tools and reference databases, each designed with a specific purpose in mind. RESULTS: In this work, we have created the workflow ARGprofiler to process large amounts of raw sequencing reads for studying the composition, distribution, and function of ARGs. ARGprofiler tackles the challenge of deciding which reference database to use by providing the PanRes database of 14 078 unique ARGs that combines several existing collections into one. Our pipeline is designed to not only produce abundance tables of genes and microbes but also to reconstruct the flanking regions of ARGs with ARGextender. ARGextender is a bioinformatic approach combining KMA and SPAdes to recruit reads for a targeted de novo assembly. While our aim is on ARGs, the pipeline also creates Mash sketches for fast searching and comparisons of sequencing runs. AVAILABILITY AND IMPLEMENTATION: The ARGprofiler pipeline is a Snakemake workflow that supports the reuse of metagenomic sequencing data and is easily installable and maintained at https://github.com/genomicepidemiology/ARGprofiler.

Oxamniquine derivatives overcome Praziquantel treatment limitations for Schistosomiasis.

Human schistosomiasis is a neglected tropical disease caused by Schistosoma mansoni, S. haematobium, and S. japonicum. Praziquantel (PZQ) is the method of choice for treatment. Due to constant selection pressure, there is an urgent need for new therapies for schistosomiasis. Previous treatment of S. mansoni included the use of oxamniquine (OXA), a drug that is activated by a schistosome sulfotransferase (SULT). Guided by data from X-ray crystallography and Schistosoma killing assays more than 350 OXA derivatives were designed, synthesized, and tested. We were able to identify CIDD-0150610 and CIDD-0150303 as potent derivatives in vitro that kill (100%) of all three Schistosoma species at a final concentration of 71.5 µM. We evaluated the efficacy of the best OXA derivates in an in vivo model after treatment with a single dose of 100 mg/kg by oral gavage. The highest rate of worm burden reduction was achieved by CIDD -150303 (81.8%) against S. mansoni, CIDD-0149830 (80.2%) against S. haematobium and CIDD-066790 (86.7%) against S. japonicum. We have also evaluated the ability of the derivatives to kill immature stages since PZQ does not kill immature schistosomes. CIDD-0150303 demonstrated (100%) killing for all life stages at a final concentration of 143 µM in vitro and effective reduction in worm burden in vivo against S. mansoni. To understand how OXA derivatives fit in the SULT binding pocket, X-ray crystal structures of CIDD-0150303 and CIDD-0150610 demonstrate that the SULT active site will accommodate further modifications to our most active compounds as we fine tune them to increase favorable pharmacokinetic properties. Treatment with a single dose of 100 mg/kg by oral gavage with co-dose of PZQ + CIDD-0150303 reduced the worm burden of PZQ resistant parasites in an animal model by 90.8%. Therefore, we conclude that CIDD-0150303, CIDD-0149830 and CIDD-066790 are novel drugs that overcome some of PZQ limitations, and CIDD-0150303 can be used with PZQ in combination therapy.

Engineered mischarged transfer RNAs for correcting pathogenic missense mutations.

Missense mutations account for approximately 50% of pathogenic mutations in human genetic diseases, and most lack effective treatments. Gene therapies, gene editing, and RNA therapies, including transfer RNA (tRNA) modalities, are common strategies for genetic disease treatments. However, reported tRNA therapies are for nonsense mutations only. It has not been explored how tRNAs can be engineered to correct missense mutations. Here, we describe missense-correcting tRNAs (mc-tRNAs) as a potential therapeutic for correcting pathogenic missense mutations. Mc-tRNAs are engineered tRNAs charged with one amino acid, but read codons of another in translation. We first developed a series of fluorescent protein-based reporters that indicate the successful correction of missense mutations via restoration of fluorescence. We engineered mc-tRNAs that effectively corrected serine and arginine missense mutations in the reporters and confirmed the amino acid substitution by mass spectrometry and mc-tRNA expression by sequencing. We examined the transcriptome response to mc-tRNA expression and found some mc-tRNAs induced minimum transcriptomic changes. Furthermore, we applied an mc-tRNA to rescue a pathogenic CAPN3 Arg-to-Gln mutant involved in LGMD2A. These results establish a versatile pipeline for mc-tRNA engineering and demonstrate the potential of mc-tRNA as an alternative therapeutic platform for the treatment of genetic disorders.

Msp1 Is a Membrane Protein Dislocase for Tail-Anchored Proteins.

Mislocalized tail-anchored (TA) proteins of the outer mitochondrial membrane are cleared by a newly identified quality control pathway involving the conserved eukaryotic protein Msp1 (ATAD1 in humans). Msp1 is a transmembrane AAA-ATPase, but its role in TA protein clearance is not known. Here, using purified components reconstituted into proteoliposomes, we show that Msp1 is both necessary and sufficient to drive the ATP-dependent extraction of TA proteins from the membrane. A crystal structure of the Msp1 cytosolic region modeled into a ring hexamer suggests that active Msp1 contains a conserved membrane-facing surface adjacent to a central pore. Structure-guided mutagenesis of the pore residues shows that they are critical for TA protein extraction in vitro and for functional complementation of an msp1 deletion in yeast. Together, these data provide a molecular framework for Msp1-dependent extraction of mislocalized TA proteins from the outer mitochondrial membrane.

Genetic findings in people with schwannomas who do not meet clinical diagnostic criteria for NF2-related schwannomatosis.

BACKGROUND: Most schwannomas are isolated tumours occurring in otherwise healthy people. However, bilateral vestibular schwannomas (BVS) or multiple non-vestibular schwannomas indicate an underlying genetic predisposition. This is most commonly NF2-related schwannomatosis (SWN), but when BVS are absent, this can also indicate SMARCB1-related or LZTR1-related SWN. METHODS: We assessed the variant detection rates for the three major SWN genes (NF2, LZTR1 and SMARCB1) in 154 people, from 150 families, who had at least one non-vestibular schwannoma, but who did not meet clinical criteria for NF2-related SWN at the time of genetic testing. RESULTS: We found that 17 (11%) people from 13 families had a germline SMARCB1 variant and 19 (12%) unrelated individuals had a germline LZTR1 variant. 19 people had an NF2 variant, but 18 of these were mosaic and 17 were only detected when 2 tumours were available for testing. The overall detection rate was 25% using blood alone, but increased to 36% when tumour analysis was included. Another 12 people had a germline variant of uncertain significance (VUS). CONCLUSIONS: There were similar proportions of LZTR1, SMARCB1 or mosaic NF2. However, since an NF2 variant was detected in tumours from 103 people, it is likely that further cases of mosaicism would be detected if more people had additional tumours available for analysis. In addition, if further evidence becomes available to show that the VUSs are pathogenic, this would significantly increase the proportion of people with a genetic diagnosis. Our results indicate the importance of comprehensive genetic testing and improved variant classification.

Single-cell transcriptome and accessible chromatin dynamics during endocrine pancreas development.

Delineating gene regulatory networks that orchestrate cell-type specification is a continuing challenge for developmental biologists. Single-cell analyses offer opportunities to address these challenges and accelerate discovery of rare cell lineage relationships and mechanisms underlying hierarchical lineage decisions. Here, we describe the molecular analysis of mouse pancreatic endocrine cell differentiation using single-cell transcriptomics, chromatin accessibility assays coupled to genetic labeling, and cytometry-based cell purification. We uncover transcription factor networks that delineate ß-, α-, and δ-cell lineages. Through genomic footprint analysis, we identify transcription factor-regulatory DNA interactions governing pancreatic cell development at unprecedented resolution. Our analysis suggests that the transcription factor Neurog3 may act as a pioneer transcription factor to specify the pancreatic endocrine lineage. These findings could improve protocols to generate replacement endocrine cells from renewable sources, like stem cells, for diabetes therapy.

Self-administered intranasal etripamil using a symptom-prompted, repeat-dose regimen for atrioventricular-nodal-dependent supraventricular tachycardia (RAPID): a multicentre, randomised trial.

BACKGROUND: Etripamil is a fast-acting, intranasally administered calcium-channel blocker in development for on-demand therapy outside a health-care setting for paroxysmal supraventricular tachycardia. We aimed to evaluate the efficacy and safety of etripamil 70 mg nasal spray using a symptom-prompted, repeat-dose regimen for acute conversion of atrioventricular-nodal-dependent paroxysmal supraventricular tachycardia to sinus rhythm within 30 min. METHODS: RAPID was a multicentre, randomised, placebo-controlled, event-driven trial, conducted at 160 sites in North America and Europe as part 2 of the NODE-301 study. Eligible patients were aged at least 18 years and had a history of paroxysmal supraventricular tachycardia with sustained, symptomatic episodes (≥20 min) as documented by electrocardiogram. Patients were administered two test doses of intranasal etripamil (each 70 mg, 10 min apart) during sinus rhythm; those who tolerated the test doses were randomly assigned (1:1) using an interactive response technology system to receive either etripamil or placebo. Prompted by symptoms of paroxysmal supraventricular tachycardia, patients self-administered a first dose of intranasal 70 mg etripamil or placebo and, if symptoms persisted beyond 10 min, a repeat dose. Continuously recorded electrocardiographic data were adjudicated, by individuals masked to patient assignment, for the primary endpoint of time to conversion of paroxysmal supraventricular tachycardia to sinus rhythm for at least 30 s within 30 min after the first dose, which was measured in all patients who administered blinded study drug for a confirmed atrioventricular-nodal-dependent event. Safety outcomes were assessed in all patients who self-administered blinded study drug for an episode of perceived paroxysmal supraventricular tachycardia. This trial is registered at ClinicalTrials.gov, NCT03464019, and is complete. FINDINGS: Between Oct 13, 2020, and July 20, 2022, among 692 patients randomly assigned, 184 (99 from the etripamil group and 85 from the placebo group) self-administered study drug for atrioventricular-nodal-dependent paroxysmal supraventricular tachycardia, with diagnosis and timing confirmed. Kaplan-Meier estimates of conversion rates by 30 min were 64% (63/99) with etripamil and 31% (26/85) with placebo (hazard ratio 2·62; 95% CI 1·66-4·15; p<0·0001). Median time to conversion was 17·2 min (95% CI 13·4-26·5) with the etripamil regimen versus 53·5 min (38·7-87·3) with placebo. Prespecified sensitivity analyses of the primary assessment were conducted to test robustness, yielding supporting results. Treatment-emergent adverse events occurred in 68 (50%) of 99 patients treated with etripamil and 12 (11%) of 85 patients in the placebo group, most of which were located at the administration site and were mild or moderate, and all of which were transient and resolved without intervention. Adverse events occurring in at least 5% of patients treated with etripamil were nasal discomfort (23%), nasal congestion (13%), and rhinorrhea (9%). No serious etripamil-related adverse events or deaths were reported. INTERPRETATION: Using a symptom-prompted, self-administered, initial and optional-repeat-dosing regimen, intranasal etripamil was well tolerated, safe, and superior to placebo for the rapid conversion of atrioventricular-nodal-dependent paroxysmal supraventricular tachycardia to sinus rhythm. This approach could empower patients to treat paroxysmal supraventricular tachycardia themselves outside of a health-care setting, and has the potential to reduce the need for additional medical interventions, such as intravenous medications given in an acute-care setting. FUNDING: Milestone Pharmaceuticals.

Scaling neighbor joining to one million taxa with dynamic and heuristic neighbor joining.

MOTIVATION: The neighbor-joining (NJ) algorithm is a widely used method to perform iterative clustering and forms the basis for phylogenetic reconstruction in several bioinformatic pipelines. Although NJ is considered to be a computationally efficient algorithm, it does not scale well for datasets exceeding several thousand taxa (>100 000). Optimizations to the canonical NJ algorithm have been proposed; these optimizations are, however, achieved through approximations or extensive memory usage, which is not feasible for large datasets. RESULTS: In this article, two new algorithms, dynamic neighbor joining (DNJ) and heuristic neighbor joining (HNJ), are presented, which optimize the canonical NJ method to scale to millions of taxa without increasing the memory requirements. Both DNJ and HNJ outperform the current gold standard methods to construct NJ trees, while DNJ is guaranteed to produce exact NJ trees. AVAILABILITY AND IMPLEMENTATION: https://bitbucket.org/genomicepidemiology/ccphylo.git. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

A recommendation for the use of electrical biosensing technology in neonatology.

Non-invasive cardiac output monitoring, via electrical biosensing technology (EBT), provides continuous, multi-parameter hemodynamic variable monitoring which may allow for timely identification of hemodynamic instability in some neonates, providing an opportunity for early intervention that may improve neonatal outcomes. EBT encompasses thoracic (TEBT) and whole body (WBEBT) methods. Despite the lack of relative accuracy of these technologies, as compared to transthoracic echocardiography, the use of these technologies in neonatology, both in the research and clinical arena, have increased dramatically over the last 30 years. The European Society of Pediatric Research Special Interest Group in Non-Invasive Cardiac Output Monitoring, a group of experienced neonatologists in the field of EBT, deemed it appropriate to provide recommendations for the use of TEBT and WBEBT in the field of neonatology. Although TEBT is not an accurate determinant of cardiac output or stroke volume, it may be useful for monitoring longitudinal changes of hemodynamic parameters. Few recommendations can be made for the use of TEBT in common neonatal clinical conditions. It is recommended not to use WBEBT to monitor cardiac output. The differences in technologies, study methodologies and data reporting should be addressed in ongoing research prior to introducing EBT into routine practice. IMPACT STATEMENT: TEBT is not recommended as an accurate determinant of cardiac output (CO) (or stroke volume (SV)). TEBT may be useful for monitoring longitudinal changes from baseline of hemodynamic parameters on an individual patient basis. TEBT-derived thoracic fluid content (TFC) longitudinal changes from baseline may be useful in monitoring progress in respiratory disorders and circulatory conditions affecting intrathoracic fluid volume. Currently there is insufficient evidence to make any recommendations regarding the use of WBEBT for CO monitoring in neonates. Further research is required in all areas prior to the implementation of these monitors into routine clinical practice.

Is age of onset and duration of stimulant therapy for ADHD associated with cocaine, methamphetamine, and prescription stimulant misuse?

BACKGROUND: To assess whether age of onset and duration of stimulant therapy for attention-deficit/hyperactivity disorder (ADHD) are associated with cocaine, methamphetamine, and prescription stimulant misuse during adolescence. METHODS: Nationally representative samples of US 10th and 12th grade students (N = 150,395) from the Monitoring the Future study were surveyed via self-administered questionnaires from 16 annual surveys (2005-2020). RESULTS: An estimated 8.2% of youth received stimulant therapy for ADHD during their lifetime (n = 10,937). More than one in 10 of all youth reported past-year prescription stimulant misuse (10.4%)-past-year cocaine (4.4%) and methamphetamine (2.0%) use were less prevalent. Youth who initiated early stimulant therapy for ADHD (≤9 years old) and for long duration (≥6 years) did not have significantly increased adjusted odds of cocaine or methamphetamine use relative to population controls (ie, non-ADHD and unmedicated ADHD youth). Youth who initiated late stimulant therapy for ADHD (≥10 years old) and for short duration (<1 year) had significantly higher odds of past-year cocaine or prescription stimulant misuse in adolescence than those initiating early stimulant therapy for ADHD (≤9 years old) and for long duration (≥6 years). Youth who initiated late stimulant therapy for ADHD (≥10 years) for short duration (<1 year) had significantly higher odds of past-year cocaine, methamphetamine, and prescription stimulant misuse versus population controls during adolescence. No differences in past-year cocaine, methamphetamine, and prescription stimulant misuse were found between individuals who only used non-stimulant therapy for ADHD relative to youth who initiated early stimulant therapy (≤9 years old) and for long duration (≥6 years). CONCLUSIONS: An inverse relationship was found between years of stimulant therapy and illicit and prescription stimulant misuse. Adolescents with later initiation and/or shorter duration of stimulant treatment for ADHD should be monitored for potential illicit and prescription stimulant misuse.

Evaluation of respondent-driven sampling in seven studies of people who use drugs from rural populations: findings from the Rural Opioid Initiative.

BACKGROUND: Accurate prevalence estimates of drug use and its harms are important to characterize burden and develop interventions to reduce negative health outcomes and disparities. Lack of a sampling frame for marginalized/stigmatized populations, including persons who use drugs (PWUD) in rural settings, makes this challenging. Respondent-driven sampling (RDS) is frequently used to recruit PWUD. However, the validity of RDS-generated population-level prevalence estimates relies on assumptions that should be evaluated. METHODS: RDS was used to recruit PWUD across seven Rural Opioid Initiative studies between 2018-2020. To evaluate RDS assumptions, we computed recruitment homophily and design effects, generated convergence and bottleneck plots, and tested for recruitment and degree differences. We compared sample proportions with three RDS-adjusted estimators (two variations of RDS-I and RDS-II) for five variables of interest (past 30-day use of heroin, fentanyl, and methamphetamine; past 6-month homelessness; and being positive for hepatitis C virus (HCV) antibody) using linear regression with robust confidence intervals. We compared regression estimates for the associations between HCV positive antibody status and (a) heroin use, (b) fentanyl use, and (c) age using RDS-1 and RDS-II probability weights and no weights using logistic and modified Poisson regression and random-effects meta-analyses. RESULTS: Among 2,842 PWUD, median age was 34 years and 43% were female. Most participants (54%) reported opioids as their drug of choice, however regional differences were present (e.g., methamphetamine range: 4-52%). Many recruitment chains were not long enough to achieve sample equilibrium. Recruitment homophily was present for some variables. Differences with respect to recruitment and degree varied across studies. Prevalence estimates varied only slightly with different RDS weighting approaches, most confidence intervals overlapped. Variations in measures of association varied little based on weighting approach. CONCLUSIONS: RDS was a useful recruitment tool for PWUD in rural settings. However, several violations of key RDS assumptions were observed which slightly impacts estimation of proportion although not associations.

Histopathology, mRNA expression profile, and donor-derived cell-free DNA for assessment of rejection in pediatric heart transplantation.

BACKGROUND: The relationship between histopathologic and molecular ("MMDx"®) assessments of endomyocardial biopsy (EMB) and serum donor-derived cell-free DNA (ddcfDNA) in acute rejection (AR) assessment following pediatric heart transplantation (HT) is unknown. METHODS: EMB sent for MMDx and histopathology from November 2021 to September 2022 were reviewed. MMDx and histopathology results were compared. DdcfDNA obtained ≤1 week prior to EMB were compared with histopathology and MMDx results. The discrimination of ddcfDNA for AR was assessed using receiver-operating curves. FINDINGS: In this study, 177 EMBs were obtained for histopathology and MMDx, 101 had time-matched ddcfDNA values. MMDx and Histopathology displayed moderate agreement for T-cell-mediated rejection (TCMR, Kappa = 0.52, p < .001) and antibody-mediated rejection (ABMR, Kappa = 0.41, p < .001). Discordant results occurred in 24% of cases, most often with ABMR. Compared with no AR, ddcfDNA values were elevated in cases of AR diagnosed by both histopathology and MMDx (p < .01 for all). Additionally, ddcfDNA values were elevated in injury patterns on MMDx, even when AR was not present (p = .01). DdcfDNA displayed excellent discrimination (AUC 0.83) for AR by MMDx and/or histopathology. Using a threshold of ≥0.135%, ddcfDNA had a sensitivity of 90%, specificity of 63%, PPV of 52%, and NPV of 94%. CONCLUSIONS: Histopathology and MMDx displayed moderate agreement in diagnosing AR following pediatric HT, with most discrepancies noted in the presence of ABMR. DdcfDNA is elevated with AR, with excellent discrimination and high NPV particularly when utilizing MMDx. A combination of all three tests may be necessary in some cases.