Structure of a human monoclonal antibody in complex with Outer surface protein C (OspC) of the Lyme disease spirochete, Borreliella burgdorferi.

Lyme disease is a tick-borne, multisystem infection caused by the spirochete, Borreliella burgdorferi . Although antibodies have been implicated in the resolution of Lyme disease, the specific B cell epitopes targeted during human infections remain largely unknown. In this study, we characterized and defined the structural epitope of a patient-derived bactericidal monoclonal IgG ("B11") against Outer surface protein C (OspC), a homodimeric lipoprotein necessary for B. burgdorferi tick-mediated transmission and early-stage colonization of vertebrate hosts. High-resolution epitope mapping was accomplished through hydrogen deuterium exchange-mass spectrometry (HDX-MS) and X-ray crystallography. Structural analysis of B11 Fab-OspC A complexes revealed the B11 Fabs associated in a 1:1 stoichiometry with the lateral faces of OspC A homodimers such that the antibodies are essentially positioned perpendicular to the spirochete's outer surface. B11's primary contacts reside within the membrane proximal regions of α-helices 1 and 6 and adjacent loops 5 and 6 in one OspC A monomer. In addition, B11 spans the OspC A dimer interface, engaging opposing α-helix 1', α-helix 2', and loop 2-3' in the second OspC A monomer. The B11-OspC A structure is reminiscent of the recently solved mouse transmission blocking monoclonal IgG B5 in complex with OspC A , indicating a mode of engagement with OspC that is conserved across species. In conclusion, we provide the first detailed insight into the interaction between a functional human antibody and an immunodominant Lyme disease antigen long considered an important vaccine target.

Synergizing Safety: A Customized Approach to Curtailing Unplanned Extubations through Shared Decision-making in the NICU.

Background: Unplanned Extubation (UE) remains an important patient safety issue in the Neonatal Intensive Care Unit. Our SMART AIM was to decrease the rate of UE by 10% from the baseline from January to December 2022 by emphasizing collaboration among healthcare professionals and through the use of shared decision-making. Methods: We established an interdisciplinary Quality Improvement team composed of nurses, respiratory therapists, and physicians (MDs). The definition of UE was standardized. UE was audited using an apparent cause analysis form to discern associated causes and pinpoint areas for improvement. Interventions were implemented in a step-by-step fashion and reviewed monthly using the model for improvement. A shared decision-making approach fostered collaborative problem-solving. Results: Our baseline UE rate was 2.3 per 100 ventilator days. Retaping, general bedside care, and position change accounted for over 50% of the UE events in 2022. The rate of UE was reduced by 48% by the end of December 2022. We achieved special-cause variation by the end of March 2023. Conclusions: The sole education of medical and nursing providers about various approaches to decreasing unnecessary retaping was ineffective in reducing UE rates. Shared decision-making incorporating inputs from nurses, respiratory therapists, and MDs led to a substantial reduction in the UE rate and underscores the potential of systematic evaluation of risk factors combined with collaborative best practices.

Language-specific phonological skills and the relationship with reading accuracy in Sylheti-English sequential bilinguals.

This study investigated the influence of first language (L1) phonology on second language (L2) early reading skills in Sylheti-English bilinguals (N = 58; 48% girls; British Bangladeshi) and their monolingual-English peers (N = 43; 45% girls; 96% White British, 4% multiethnic British) in a diaspora context. Language-specific phonological awareness and nonword repetition were tested at two time points (6;2-7;8 years-old). At Time 1, the bilinguals had lower productive accuracy for phonological sequences that violated their L1 phonology (d = .56; .84), and these skills accounted for a significant amount of variance in their reading accuracy. At Time 2, the language-specific effects were no longer present. These findings highlight the importance of considering language structure in multilingual early literacy development.

Factors Affecting Peripheral Intravenous Catheter Placement During Pediatric Trauma Resuscitation.

INTRODUCTION: Intravenous access is required for resuscitation of injured patients but may be delayed in children because of challenges associated with peripheral intravenous (PIV) catheter placement. Early identification of factors predisposing patients to difficult PIV placement can assist in deciding strategies for timely intravenous access. METHODS: We conducted a retrospective, video-based review of injured children and adolescents treated between April 2018 and May 2019. Patient demographic, physiological, injury, and resuscitation characteristics were obtained from the patient record, including age, race, weight, injury type, Injury Severity Score, initial systolic blood pressure, initial Glasgow Coma Score, intubation status, activation level, and presence of prearrival notification. Video review was used to determine the time to PIV placement, the number of attempts required, the purpose for additional access, and the reason for abandonment of PIV placement. Multivariable regressions were used to determine factors associated with successful placement. RESULTS: During the study period, 154 consented patients underwent attempts at PIV placement in the trauma bay. Placement was successful in 139 (90.3%) patients. Older patients (OR [odds ratio]: 0.9, 95% confidence interval [CI]: 0.9, 0.9) and patients who required the highest level activation response (OR: 0.0, 95% CI: 0.0, 0.3) were less likely to have an attempt at PIV placement abandoned. Children with nonblunt injuries (OR: 11.6, 95% CI: 1.3, 119.2) and pre-existing access (OR: 39.6, 95% CI: 7.0, 350.6) were more likely to have an attempt at PIV placement abandoned. Among patients with successful PIV placement, the time required for establishing PIV access was faster as age increased (-0.5 s, 95% CI: -1.1, -0.0). CONCLUSIONS: Younger age was associated with abandonment of PIV attempts and, when successful, increased time to placement. Strategies to improve successful PIV placement and alternate routes of access should be considered early to prevent treatment delays in younger children.

Personal Protective Equipment Adherence of Pediatric Resuscitation Team Members During the COVID-19 Pandemic.

STUDY OBJECTIVE: During the COVID-19 pandemic, health care workers have had the highest risk of infection among essential workers. Although personal protective equipment (PPE) use is associated with lower infection rates, appropriate use of PPE has been variable among health care workers, even in settings with COVID-19 patients. We aimed to evaluate the patterns of PPE adherence during emergency department resuscitations that included aerosol-generating procedures. METHODS: We conducted a retrospective, video-based review of pediatric resuscitations involving one or more aerosol-generating procedures during the first 3 months of the COVID-19 pandemic in the United States (March to June 2020). Recommended adherence (complete, inadequate, absent) with 5 PPE items (headwear, eyewear, masks, gowns, gloves) and the duration of potential exposure were evaluated for individuals in the room after aerosol-generating procedure initiation. RESULTS: Among the 345 health care workers observed during 19 resuscitations, 306 (88.7%) were nonadherent (inadequate or absent adherence) with the recommended use of at least 1 PPE type at some time during the resuscitation, 23 (6.7%) of whom had no PPE. One hundred and forty health care workers (40.6%) altered or removed at least 1 type of PPE during the event. The aggregate time in the resuscitation room for health care workers across all events was 118.7 hours. During this time, providers had either absent or inadequate eyewear for 46.4 hours (39.1%) and absent or inadequate masks for 35.2 hours (29.7%). CONCLUSION: Full adherence with recommended PPE use was limited in a setting at increased risk for SARS-CoV-2 virus aerosolization. In addition to ensuring appropriate donning, approaches are needed for ensuring ongoing adherence with PPE recommendations during exposure.

Development of neural perceptual vowel spaces during the first year of life.

This study measured infants' neural responses for spectral changes between all pairs of a set of English vowels. In contrast to previous methods that only allow for the assessment of a few phonetic contrasts, we present a new method that allows us to assess changes in spectral sensitivity across the entire vowel space and create two-dimensional perceptual maps of the infants' vowel development. Infants aged four to eleven months were played long series of concatenated vowels, and the neural response to each vowel change was assessed using the Acoustic Change Complex (ACC) from EEG recordings. The results demonstrated that the youngest infants' responses more closely reflected the acoustic differences between the vowel pairs and reflected higher weight to first-formant variation. Older infants had less acoustically driven responses that seemed a result of selective increases in sensitivity for phonetically similar vowels. The results suggest that phonetic development may involve a perceptual warping for confusable vowels rather than uniform learning, as well as an overall increasing sensitivity to higher-frequency acoustic information.

Impaired myogenic development, differentiation and function in hESC-derived SMA myoblasts and myotubes.

Spinal muscular atrophy (SMA) is a severe genetic disorder that manifests in progressive neuromuscular degeneration. SMA originates from loss-of-function mutations of the SMN1 (Survival of Motor Neuron 1) gene. Recent evidence has implicated peripheral deficits, especially in skeletal muscle, as key contributors to disease progression in SMA. In this study we generated myogenic cells from two SMA-affected human embryonic stem cell (hESC) lines with deletion of SMN1 bearing two copies of the SMN2 gene and recapitulating the molecular phenotype of Type 1 SMA. We characterized myoblasts and myotubes by comparing them to two unaffected, control hESC lines and demonstrate that SMA myoblasts and myotubes showed altered expression of various myogenic markers, which translated into an impaired in vitro myogenic maturation and development process. Additionally, we provide evidence that these SMN1 deficient cells display functional deficits in cholinergic calcium signaling response, glycolysis and oxidative phosphorylation. Our data describe a novel human myogenic SMA model that might be used for interrogating the effect of SMN depletion during skeletal muscle development, and as model to investigate biological mechanisms targeting myogenic differentiation, mitochondrial respiration and calcium signaling processes in SMA muscle cells.

A Functional riboSNitch in the 3' Untranslated Region of FKBP5 Alters MicroRNA-320a Binding Efficiency and Mediates Vulnerability to Chronic Post-Traumatic Pain.

Previous studies have shown that common variants of the gene coding for FK506-binding protein 51 (FKBP5), a critical regulator of glucocorticoid sensitivity, affect vulnerability to stress-related disorders. In a previous report, FKBP5 rs1360780 was identified as a functional variant because of its effect on gene methylation. Here we report evidence for a novel functional FKBP5 allele, rs3800373. This study assessed the association between rs3800373 and post-traumatic chronic pain in 1607 women and men from two ethnically diverse human cohorts. The molecular mechanism through which rs3800373 affects adverse outcomes was established via in silico, in vivo, and in vitro analyses. The rs3800373 minor allele predicted worse adverse outcomes after trauma exposure, such that individuals with the minor (risk) allele developed more severe post-traumatic chronic musculoskeletal pain. Among these individuals, peritraumatic circulating FKBP5 expression levels increased as cortisol and glucocorticoid receptor (NR3C1) mRNA levels increased, consistent with increased glucocorticoid resistance. Bioinformatic, in vitro, and mutational analyses indicate that the rs3800373 minor allele reduces the binding of a stress- and pain-associated microRNA, miR-320a, to FKBP5 via altering the FKBP5 mRNA 3'UTR secondary structure (i.e., is a riboSNitch). This results in relatively greater FKBP5 translation, unchecked by miR-320a. Overall, these results identify an important gene-miRNA interaction influencing chronic pain risk in vulnerable individuals and suggest that exogenous methods to achieve targeted reduction in poststress FKBP5 mRNA expression may constitute useful therapeutic strategies.SIGNIFICANCE STATEMENTFKBP5 is a critical regulator of the stress response. Previous studies have shown that dysregulation of the expression of this gene plays a role in the pathogenesis of chronic pain development as well as a number of comorbid neuropsychiatric disorders. In the current study, we identified a functional allele (rs3800373) in the 3'UTR of FKBP5 that influences vulnerability to chronic post-traumatic pain in two ethnic cohorts. Using multiple complementary experimental approaches, we show that the FKBP5 rs3800373 minor allele alters the secondary structure of FKBP5 mRNA, decreasing the binding of a stress- and pain-associated microRNA, miR-320a. This results in relatively greater FKBP5 translation, unchecked by miR-320a, increasing glucocorticoid resistance and increasing vulnerability to post-traumatic pain.

Binding to SMN2 pre-mRNA-protein complex elicits specificity for small molecule splicing modifiers.

Small molecule splicing modifiers have been previously described that target the general splicing machinery and thus have low specificity for individual genes. Several potent molecules correcting the splicing deficit of the SMN2 (survival of motor neuron 2) gene have been identified and these molecules are moving towards a potential therapy for spinal muscular atrophy (SMA). Here by using a combination of RNA splicing, transcription, and protein chemistry techniques, we show that these molecules directly bind to two distinct sites of the SMN2 pre-mRNA, thereby stabilizing a yet unidentified ribonucleoprotein (RNP) complex that is critical to the specificity of these small molecules for SMN2 over other genes. In addition to the therapeutic potential of these molecules for treatment of SMA, our work has wide-ranging implications in understanding how small molecules can interact with specific quaternary RNA structures.

Contrasting Nitrogen Fate in Watersheds Using Agricultural and Water Quality Information.

Surplus nitrogen (N) estimates, principal component analysis (PCA), and end-member mixing analysis (EMMA) were used in a multisite comparison contrasting the fate of N in diverse agricultural watersheds. We applied PCA-EMMA in 10 watersheds located in Indiana, Iowa, Maryland, Nebraska, Mississippi, and Washington ranging in size from 5 to 1254 km with four nested watersheds. Watershed Surplus N was determined by subtracting estimates of crop uptake and volatilization from estimates of N input from atmospheric deposition, plant fixation, fertilizer, and manure for the period from 1987 to 2004. Watershed average Surplus N ranged from 11 to 52 kg N ha and from 9 to 32% of N input. Solute concentrations in streams, overland runoff, tile drainage, groundwater (GW), streambeds, and the unsaturated zone were used in the PCA-EMMA procedure to identify independent components contributing to observed stream concentration variability and the end-members contributing to streamflow and NO load. End-members included dilute runoff, agricultural runoff, benthic-processing, tile drainage, and oxic and anoxic GW. Surplus N was larger in watersheds with more permeable soils (Washington, Nebraska, and Maryland) that allowed greater infiltration, and oxic GW was the primary source of NO load. Subsurface transport of NO in these watersheds resulted in some removal of Surplus N by denitrification. In less permeable watersheds (Iowa, Indiana, and Mississippi), NO was rapidly transported to the stream by tile drainage and runoff with little removal. Evidence of streambed removal of NO by benthic diatoms was observed in the larger watersheds.

Specific Correction of Alternative Survival Motor Neuron 2 Splicing by Small Molecules: Discovery of a Potential Novel Medicine To Treat Spinal Muscular Atrophy.

Spinal muscular atrophy (SMA) is the leading genetic cause of infant and toddler mortality, and there is currently no approved therapy available. SMA is caused by mutation or deletion of the survival motor neuron 1 (SMN1) gene. These mutations or deletions result in low levels of functional SMN protein. SMN2, a paralogous gene to SMN1, undergoes alternative splicing and exclusion of exon 7, producing an unstable, truncated SMNΔ7 protein. Herein, we report the identification of a pyridopyrimidinone series of small molecules that modify the alternative splicing of SMN2, increasing the production of full-length SMN2 mRNA. Upon oral administration of our small molecules, the levels of full-length SMN protein were restored in two mouse models of SMA. In-depth lead optimization in the pyridopyrimidinone series culminated in the selection of compound 3 (RG7800), the first small molecule SMN2 splicing modifier to enter human clinical trials.

SMN Protein Can Be Reliably Measured in Whole Blood with an Electrochemiluminescence (ECL) Immunoassay: Implications for Clinical Trials.

Spinal muscular atrophy (SMA) is caused by defects in the survival motor neuron 1 (SMN1) gene that encodes survival motor neuron (SMN) protein. The majority of therapeutic approaches currently in clinical development for SMA aim to increase SMN protein expression and there is a need for sensitive methods able to quantify increases in SMN protein levels in accessible tissues. We have developed a sensitive electrochemiluminescence (ECL)-based immunoassay for measuring SMN protein in whole blood with a minimum volume requirement of 5µL. The SMN-ECL immunoassay enables accurate measurement of SMN in whole blood and other tissues. Using the assay, we measured SMN protein in whole blood from SMA patients and healthy controls and found that SMN protein levels were associated with SMN2 copy number and were greater in SMA patients with 4 copies, relative to those with 2 and 3 copies. SMN protein levels did not vary significantly in healthy individuals over a four-week period and were not affected by circadian rhythms. Almost half of the SMN protein was found in platelets. We show that SMN protein levels in C/C-allele mice, which model a mild form of SMA, were high in neonatal stage, decreased in the first few weeks after birth, and then remained stable throughout the adult stage. Importantly, SMN protein levels in the CNS correlated with SMN levels measured in whole blood of the C/C-allele mice. These findings have implications for the measurement of SMN protein induction in whole blood in response to SMN-upregulating therapy.

Fatigue and carnitine levels over multiple cycles of chemotherapy in children and adolescents.

PURPOSE: Fatigue in childhood cancer is a pervasive and distressing symptom described as a "lack of energy". Carnitine is a micronutrient used to transport long chain fatty acids into muscle mitochondria. Some chemotherapy drugs interfere with the carnitine network. Both carnitine and fatigue relate to physical energy and may be influenced by chemotherapy. Using a repeated measures design, change in carnitine levels and change in fatigue in childhood cancer patients receiving ifosfamide, cisplatin, or doxorubicin were examined over multiple chemotherapy cycles. The influence of carnitine levels on fatigue was evaluated. METHODS AND SAMPLE: Fifty-eight patients, between ages 3 and 18 years, within two months from diagnosis and receiving cisplatin, doxorubicin, and/or ifosfamide chemotherapy drugs, participated. Measurements included carnitine plasma levels and self-reported fatigue using established child or adolescent fatigue scales and were collected during the 2nd cycle of chemotherapy, and repeated on alternating cycles up to cycle 8. The Parent Fatigue Scale was used for children under age 7. KEY RESULTS: Total and free carnitine levels did not change significantly for the group. Fatigue decreased significantly in children age 7-12 (p = 0.04). Relationships between fatigue and carnitine were not significant. CONCLUSIONS: Changes in carnitine plasma levels were not significant in this sample of patients. The carnitine levels remained within the reference values for children and were not associated with fatigue levels. School-age children may be more resilient to fatigue over the trajectory of treatment. Further research is needed into the biologic mechanisms of fatigue.

Motor neuron disease. SMN2 splicing modifiers improve motor function and longevity in mice with spinal muscular atrophy.

Spinal muscular atrophy (SMA) is a genetic disease caused by mutation or deletion of the survival of motor neuron 1 (SMN1) gene. A paralogous gene in humans, SMN2, produces low, insufficient levels of functional SMN protein due to alternative splicing that truncates the transcript. The decreased levels of SMN protein lead to progressive neuromuscular degeneration and high rates of mortality. Through chemical screening and optimization, we identified orally available small molecules that shift the balance of SMN2 splicing toward the production of full-length SMN2 messenger RNA with high selectivity. Administration of these compounds to Δ7 mice, a model of severe SMA, led to an increase in SMN protein levels, improvement of motor function, and protection of the neuromuscular circuit. These compounds also extended the life span of the mice. Selective SMN2 splicing modifiers may have therapeutic potential for patients with SMA.

Speech perception and production by sequential bilingual children: a longitudinal study of voice onset time acquisition.

The majority of bilingual speech research has focused on simultaneous bilinguals. Yet, in immigrant communities, children are often initially exposed to their family language (L1), before becoming gradually immersed in the host country's language (L2). This is typically referred to as sequential bilingualism. Using a longitudinal design, this study explored the perception and production of the English voicing contrast in 55 children (40 Sylheti-English sequential bilinguals and 15 English monolinguals). Children were tested twice: when they were in nursery (52-month-olds) and 1 year later. Sequential bilinguals' perception and production of English plosives were initially driven by their experience with their L1, but after starting school, changed to match that of their monolingual peers.

SMA-MAP: a plasma protein panel for spinal muscular atrophy.

OBJECTIVES: Spinal Muscular Atrophy (SMA) presents challenges in (i) monitoring disease activity and predicting progression, (ii) designing trials that allow rapid assessment of candidate therapies, and (iii) understanding molecular causes and consequences of the disease. Validated biomarkers of SMA motor and non-motor function would offer utility in addressing these challenges. Our objectives were (i) to discover additional markers from the Biomarkers for SMA (BforSMA) study using an immunoassay platform, and (ii) to validate the putative biomarkers in an independent cohort of SMA patients collected from a multi-site natural history study (NHS). METHODS: BforSMA study plasma samples (N = 129) were analyzed by immunoassay to identify new analytes correlating to SMA motor function. These immunoassays included the strongest candidate biomarkers identified previously by chromatography. We selected 35 biomarkers to validate in an independent cohort SMA type 1, 2, and 3 samples (N = 158) from an SMA NHS. The putative biomarkers were tested for association to multiple motor scales and to pulmonary function, neurophysiology, strength, and quality of life measures. We implemented a Tobit model to predict SMA motor function scores. RESULTS: 12 of the 35 putative SMA biomarkers were significantly associated (p<0.05) with motor function, with a 13(th) analyte being nearly significant. Several other analytes associated with non-motor SMA outcome measures. From these 35 biomarkers, 27 analytes were selected for inclusion in a commercial panel (SMA-MAP) for association with motor and other functional measures. CONCLUSIONS: Discovery and validation using independent cohorts yielded a set of SMA biomarkers significantly associated with motor function and other measures of SMA disease activity. A commercial SMA-MAP biomarker panel was generated for further testing in other SMA collections and interventional trials. Future work includes evaluating the panel in other neuromuscular diseases, for pharmacodynamic responsiveness to experimental SMA therapies, and for predicting functional changes over time in SMA patients.

5 strategies for building a top-performing hospital.

A hospital's strategy for attaining high performance under value-based business models should focus on five key objectives: Building meaningful scale and scope; Focusing on more integrated care delivery and management; Attaining demonstrably high levels of clinical quality; Differentiating from the competition through superior customer service; Establishing a competitive cost position.