Long-term effect of pneumococcal conjugate vaccines on invasive pneumococcal disease incidence among people of all ages from national, active, laboratory-based surveillance in South Africa, 2005-19: a cohort observational study.

BACKGROUND: In South Africa, 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in 2009 and 13-valent PCV (PCV13) was introduced in 2011, both in a two plus one schedule. We evaluated the ongoing effects of PCV on the prevention of invasive pneumococcal disease (IPD) over 15 years of sustained surveillance in South Africa before the COVID-19 pandemic. METHODS: We conducted national, active, laboratory-based surveillance for IPD among all ages in South Africa, including isolate serotyping and susceptibility testing. We fitted linear regression models with vaccine covariates to imputed IPD case counts each year by serotype and age to compare expected and actual IPD cases in 2019, which was the main outcome. Vaccine effects were set to zero to identify expected incidence after the introduction of PCV7 and PCV13. FINDINGS: From Jan 1, 2005, to Dec 31, 2019, surveillance identified 52 957 IPD cases. Among the 50 705 individuals with age data available, 9398 (18·5%) were infants aged younger than 2 years. Compared with expected case numbers (no vaccination) predicted using all available data, overall IPD rates among children younger than 2 years declined by 76·0% (percentage risk difference; 95% CI -79·0 to -72·8%) in 2019; notably, PCV7 and additional PCV13 serotype IPD rates declined by 95·5% (-97·0 to -93·4%) and 93·8% (-96·2 to-90·5%), respectively, whereas non-vaccine serotypes (NVTs) did not change significantly. Among adults aged 25-44 years, overall IPD declined by 50·4% (-54·2 to -46·3%), and PCV7 and additional PCV13 serotype IPD rates declined by 86·1% (-88·7 to -83·1%) and 77·2% (-80·9 to -73·0%), respectively, whereas NVTs increased by 78·5% (56·8 to 103·4%). Individuals aged older than 64 years also benefited from declines in IPD (-30·2%; -41·9 to -16·2%), but NVTs increased (234·9%; 138·1 to 379·4%). INTERPRETATION: We documented sustained direct and indirect benefits of PCV across age groups, and NVT increases in adults older than 24 years. Higher valency PCVs would have the added benefit of preventing this residual disease. FUNDING: National Institute for Communicable Diseases of the National Health Laboratory Service (South Africa) and US Agency for International Development Antimicrobial Resistance Initiative, US Centers for Disease Control and Prevention.

Explaining International Trends in Mortality on Hemodialysis Through Changes in Hemodialysis Practices in the Dialysis Outcomes and Practice Patterns Study (DOPPS).

RATIONALE & OBJECTIVE: Case-mix adjusted hemodialysis mortality has decreased since 1998. Many factors that influence mortality may have contributed to this trend and these associations may differ by continental region. We studied changes in hemodialysis facility practices over time and their potential role in mediating changes in patient survival. STUDY DESIGN: Observational prospective cohort study. SETTING & PARTICIPANTS: Adult hemodialysis patients treated in hemodialysis 500 facilities participating in the Dialysis Outcomes Practice Patterns Study (DOPPS) between 1999 and 2015 in the US, Japan, and 4 four European countries: Germany, Italy, Spain, and UK. PREDICTORS: Four practice measures at each facility: the percentages of patients with Kt/V>1.2, interdialytic weight gain [IDWG]<5.7%, phosphorus<6 mg/dL, and using AV fistulae. OUTCOMES: Patient survival. ANALYTICAL APPROACH: Mediation analyses, adjusted for case mix, were conducted using 3-year study phase as the exposure and facility practice measures as potential mediators. RESULTS: In Europe, we observed a 13% improvement in overall case-mix adjusted survival per decade. Trends in facility practice measures, especially Kt/V and phosphorus, explained 10% improvement in case-mix survival per decade, representing 77% (10% explained of 13% improvement) of the observed improvement. In Japan, 73% of the observed 12%/decade improvement in case-mix adjusted survival could be attributed to facility practices, especially Kt/V and IDWG. In the US, 56% of the observed 47%/decade improvement in case-mix adjusted survival could be attributed to facility practices, especially AV fistula use and phosphorus control. LIMITATIONS: Unmeasured changes in the characteristics of the patient population over this period may confound the observed associations. CONCLUSION: The improvements in adjusted hemodialysis patient survival in Europe, Japan, and the US from 1999 to 2015 can be largely explained by improvements in specific facility practices. Future changes in patient survival may be responsive to further evolution in the implementation of common clinical practices.

Multimodal analysis of dysregulated heme metabolism, hypoxic signaling, and stress erythropoiesis in Down syndrome.

Down syndrome (DS), the genetic condition caused by trisomy 21 (T21), is characterized by delayed neurodevelopment, accelerated aging, and increased risk of many co-occurring conditions. Hypoxemia and dysregulated hematopoiesis have been documented in DS, but the underlying mechanisms and clinical consequences remain ill defined. We report an integrative multi-omic analysis of ∼400 research participants showing that people with DS display transcriptomic signatures indicative of elevated heme metabolism and increased hypoxic signaling across the lifespan, along with chronic overproduction of erythropoietin, elevated biomarkers of tissue-specific hypoxia, and hallmarks of stress erythropoiesis. Elevated heme metabolism, transcriptional signatures of hypoxia, and stress erythropoiesis are conserved in a mouse model of DS and associated with overexpression of select triplicated genes. These alterations are independent of the hyperactive interferon signaling characteristic of DS. These results reveal lifelong dysregulation of key oxygen-related processes that could contribute to the developmental and clinical hallmarks of DS.

Measuring Community Urbanicity and Its Influence on Household Food Security Across Nepal's Agroecological Zones.

Background: Urbanization influences food systems and food security, but research on these associations in low- and middle-income countries remain limited, partly because of the binary and unstandardized "urban compared with rural" classifications. Objectives: To develop a community urbanicity scale, to assess its associations with household food security, and to explore whether agricultural occupation modifies this relationship across the 3 agroecological zones (mountain, hill, Tarai) of Nepal. Methods: Data came from a nationally and agroecologically representative, multistaged 2013 agri-food system survey of 4285 households with children <5 y in 63 communities (wards) in Nepal. A novel community-level urbanicity scale was constructed using factor analysis that included 8 domains. Multilevel mixed effects logistic regression was used to assess associations between urbanicity and household food security (measured using the validated Household Food Insecurity Access Scale), and to investigate modifying effects of agricultural occupation. Results: Urbanicity scores ranged between 13 and 69, of a possible 80 points. Most agricultural households in the mountains (67%) and hills (54%) were categorized food insecure. Increases in urbanicity were negatively associated with food insecurity, controlling for other factors (odds ratio [OR] per 10-unit urbanicity difference OR: 0.82; confidence interval [CI]: 0.71, 0.94; P ≤ 0.05). Agricultural occupation may have positively influenced this association though was not a statistically significant effect measure modifier (P = 0.07). Conclusions: The novel scale shows more nuance within Nepal's agroecological zones, which had similar urbanicity-to-food security relationships as well as overlapping urbanicity score distributions. Research and policy efforts should consider using scales providing more precise urbanicity measurement, and thus informative assessments on its role in predicting food insecurity, especially in agriculturally reliant populations.

JAK inhibition decreases the autoimmune burden in Down syndrome.

Individuals with Down syndrome (DS), the genetic condition caused by trisomy 21 (T21), display clear signs of immune dysregulation, including high rates of autoimmune disorders and severe complications from infections. Although it is well established that T21 causes increased interferon responses and JAK/STAT signaling, elevated autoantibodies, global immune remodeling, and hypercytokinemia, the interplay between these processes, the clinical manifestations of DS, and potential therapeutic interventions remain ill defined. Here, we report a comprehensive analysis of immune dysregulation at the clinical, cellular, and molecular level in hundreds of individuals with DS. We demonstrate multi-organ autoimmunity of pediatric onset concurrent with unexpected autoantibody-phenotype associations. Importantly, constitutive immune remodeling and hypercytokinemia occur from an early age prior to autoimmune diagnoses or autoantibody production. We then report the interim analysis of a Phase II clinical trial investigating the safety and efficacy of the JAK inhibitor tofacitinib through multiple clinical and molecular endpoints. Analysis of the first 10 participants to complete the 16-week study shows a good safety profile and no serious adverse events. Treatment reduced skin pathology in alopecia areata, psoriasis, and atopic dermatitis, while decreasing interferon scores, cytokine scores, and levels of pathogenic autoantibodies without overt immune suppression. Additional research is needed to define the effects of JAK inhibition on the broader developmental and clinical hallmarks of DS. ClinicalTrials.gov identifier: NCT04246372.

Cluster Analysis Methods to Support Population Health Improvement Among US Counties.

CONTEXT: Population health rankings can be a catalyst for the improvement of health by drawing attention to areas in need of relative improvement and summarizing complex information in a manner understood by almost everyone. However, ranks also have unintended consequences, such as being interpreted as "hard truths," where variations may not be significant. There is a need to improve communication about uncertainty in ranks, with accurate interpretation. The most common solutions discussed in the literature have included modeling approaches to minimize statistical noise or borrow strength from covariates. However, the use of complex models can limit communication and implementation, especially for broad audiences. OBJECTIVES: Explore data-informed grouping (cluster analysis) as an easier-to-understand, empirical technique to account for rank imprecision that can be effectively communicated both numerically and visually. DESIGN: Cluster analysis, specifically k-means clustering with Wasserstein (earth mover's) distance, was explored as an approach to identify natural and meaningful groupings and gaps in the data distribution for the County Health Rankings' (CHR) health outcomes ranks. SETTING: County-level health outcomes from the 2022 CHR. PARTICIPANTS: 3082 counties that were ranked in the 2022 CHR. MAIN OUTCOME MEASURE: Data-informed health groups. RESULTS: Cluster analysis identified 30 health groupings among counties nationwide, with cluster size ranging from 9 to 184 counties. On average, states had 16 identified clusters, ranging from 3 in Delaware and Hawaii to 27 in Virginia. Number of clusters per state was associated with number of counties per state and population of the state. The method helped address many of the issues that arise from providing rank estimates alone. CONCLUSIONS: Public health practitioners can use this information to understand uncertainty in ranks, visualize distances between county ranks, have context around which counties are not meaningfully different from one another, and compare county performance to peer counties.

An Early Gestation Plasma Inflammasome in Rural Bangladeshi Women.

Circulating α1-acid glycoprotein (AGP) and C-reactive protein (CRP) are commonly measured to assess inflammation, but these biomarkers fail to reveal the complex molecular biology of inflammation. We mined the maternal plasma proteome to detect proteins that covary with AGP and CRP. In 435 gravida predominantly in <12-week gestation, we correlated the relative quantification of plasma proteins assessed via a multiplexed aptamer assay (SOMAScan®) with AGP and CRP, quantified by immunoassay. We defined a plasma inflammasome as protein correlates meeting a false discovery rate <0.05. We examined potential pathways using principal component analysis. A total of 147 and 879 of 6431 detected plasma proteins correlated with AGP and CRP, respectively, of which 61 overlapped with both biomarkers. Positive correlates included serum amyloid, complement, interferon-induced, and immunoregulatory proteins. Negative correlates were micronutrient and lipid transporters and pregnancy-related anabolic proteins. The principal components (PCs) of AGP were dominated by negatively correlated anabolic proteins associated with gestational homeostasis, angiogenesis, and neurogenesis. The PCs of CRP were more diverse in function, reflecting cell surface and adhesion, embryogenic, and intracellular and extra-hepatic tissue leakage proteins. The plasma proteome of AGP or CRP reveals wide proteomic variation associated with early gestational inflammation, suggesting mechanisms and pathways that merit future research.

Early childhood height is a determinant of young adult stature in rural Nepal.

BACKGROUND: Does preschool height predict adult stature in undernourished settings? The extent to which preschool length or height forecasts young adult stature is unclear in chronically undernourished populations. METHODS: In 2006-8, we assessed height in a cohort of 2074 young adults, aged 16-23 years, in rural Nepal who, as preschoolers (≤ 4 year), were measured at baseline and again 16 months later during a vitamin A supplementation trial in 1989-91. We assessed by linear regression the ability of preschool length (L, measured < 24 mo) or height (Ht, 24-59 mo), at each year of age to predict 16-23 year old height, adjusted for month of young adult age, interval duration (in months), caste, preschool weight-for-height z-score and, in young women, time since menarche, marriage status and pregnancy history. RESULTS: Young women were a mean of 0.81, 1.11, 0.82, 0.24, 0.44 cm taller (all p < 0.01) and young men, 0.84, 1.18, 0.74, 0.64 and 0.48 cm taller (all p < 0.001) per cm of attained L/Ht at each successive preschool year of age and, overall, were 2.04 and 2.40 cm taller for each unit increase in preschool L/Ht z-score (L/HAZ) (both p < 0.001). Coefficients were generally larger for 16-month follow-up measurements. The percent of young adult height attained by children with normal L/HAZ (>-1) increased from 38-40% mid-infancy to ∼ 69-74% by 6 years of age. By 3-6 years of age heights of stunted children (L/HAZ<-2) were consistently ∼ 4-7% lower in their young adult height versus normal statured children. There was no effect of preschool vitamin A receipt. CONCLUSIONS: Shorter young children become shorter adults but predictive effects can vary by sex, age assessed, and may be influenced by year or season of measurement.

A multi-method exploration of a cardiac rehabilitation service delivered by registered Clinical Exercise Physiologists in the UK: key learnings for current and new services.

BACKGROUND: Cardiac rehabilitation has been identified as having the most homogenous clinical exercise service structure in the United Kingdom (UK), but inconsistencies are evident in staff roles and qualifications within and across services. The recognition of Clinical Exercise Physiologists (CEPs) as a registered health professional in 2021 in the UK, provides a potential solution to standardise the cardiac rehabilitation workforce. This case study examined, in a purposefully selected cardiac exercise service that employed registered CEPs, (i) how staff knowledge, skills and competencies contribute to the provision of the service, (ii) how these components assist in creating effective service teams, and (iii) the existing challenges from staff and patient perspectives. METHODS: A multi-method qualitative approach (inc., semi-structured interviews, observations, field notes and researcher reflections) was employed with the researcher immersed for 12-weeks within the service. The Consolidated Framework for Implementation Research was used as an overarching guide for data collection. Data derived from registered CEPs (n = 5), clinical nurse specialists (n = 2), dietitians (n = 1), service managers/leads (n = 2) and patients (n = 7) were thematically analysed. RESULTS: Registered CEPs delivered innovative exercise prescription based on their training, continued professional development (CPD), academic qualifications and involvement in research studies as part of the service. Exposure to a wide multidisciplinary team (MDT) allowed skill and competency transfer in areas such as clinical assessments. Developing an effective behaviour change strategy was challenging with delivery of lifestyle information more effective during less formal conversations compared to timetabled education sessions. CONCLUSIONS: Registered CEPs have the specialist knowledge and skills to undertake and implement the latest evidence-based exercise prescription in a cardiac rehabilitation setting. An MDT service structure enables a more effective team upskilling through shared peer experiences, observations and collaborative working between healthcare professionals.

Variegated overexpression of chromosome 21 genes reveals molecular and immune subtypes of Down syndrome.

Individuals with Down syndrome, the genetic condition caused by trisomy 21, exhibit strong inter-individual variability in terms of developmental phenotypes and diagnosis of co-occurring conditions. The mechanisms underlying this variable developmental and clinical presentation await elucidation. We report an investigation of human chromosome 21 gene overexpression in hundreds of research participants with Down syndrome, which led to the identification of two major subsets of co-expressed genes. Using clustering analyses, we identified three main molecular subtypes of trisomy 21, based on differential overexpression patterns of chromosome 21 genes. We subsequently performed multiomics comparative analyses among subtypes using whole blood transcriptomes, plasma proteomes and metabolomes, and immune cell profiles. These efforts revealed strong heterogeneity in dysregulation of key pathophysiological processes across the three subtypes, underscored by differential multiomics signatures related to inflammation, immunity, cell growth and proliferation, and metabolism. We also observed distinct patterns of immune cell changes across subtypes. These findings provide insights into the molecular heterogeneity of trisomy 21 and lay the foundation for the development of personalized medicine approaches for the clinical management of Down syndrome.

An Egg Intervention Improves Ponderal But Not Linear Growth Among Infants 6-12 mo of Age in Rural Bangladesh.

BACKGROUND: Animal source foods are rich in multiple nutrients. Regular egg consumption may improve infant growth in low- and middle-income countries. OBJECTIVES: To assess the impact of daily egg consumption on linear growth among 6-12-mo olds in rural Bangladesh. METHODS: We conducted a 2 × 4 factorial cluster-randomized controlled trial allocating clusters (n = 566) to treatment for enteric pathogens or placebo and a daily egg, protein supplement, isocaloric supplement, or control. All arms received nutrition education. Here, we compare the effect of the egg intervention versus control on linear growth, a prespecified aim of the trial. Infants were enrolled at 3 mo. We measured length and weight at 6 and 12 mo and visited households weekly to distribute eggs and monitor compliance. We used linear regression models to compare 12-mo mean length, weight, and z-scores for length-for-age (LAZ), weight-for-length, and weight-for-age (WAZ), and log-binomial or robust Poisson regression to compare prevalence of stunting, wasting, and underweight between arms. We used generalized estimating equations to account for clustering and adjusted models for baseline measures of outcomes. RESULTS: We enrolled 3051 infants (n = 283 clusters) across arms, with complete 6 and 12 mo anthropometry data from 1228 infants (n = 142 clusters) in the egg arm and 1109 infants (n = 141 clusters) in the control. At baseline, 18.5%, 6.0%, and 16.4% were stunted, wasted, and underweight, respectively. The intervention did not have a statistically significant effect on mean LAZ (ß: 0.05, 95% confidence interval [CI]: -0.01, 0.10) or stunting prevalence (ß: 0.98, 95% CI: 0.89, 1.13) at 12 mo. Mean weight (ß: 0.07 kg, 95% CI: 0.02, 0.11) and WAZ (ß: 0.06, 95% CI: 0.02, 0.11) were significantly higher in the egg compared with control arms. CONCLUSIONS: Provision of a daily egg for 6 mo to infants in rural Bangladesh improved ponderal but not linear growth. TRIAL REGISTRATION NUMBER: NCT03683667, https://clinicaltrials.gov/ct2/show/NCT03683667.

Perturbation-Specific Transcriptional Mapping for unbiased target elucidation of antibiotics.

The rising prevalence of antibiotic resistance threatens human health. While more sophisticated strategies for antibiotic discovery are being developed, target elucidation of new chemical entities remains challenging. In the post-genomic era, expression profiling can play an important role in mechanism-of-action (MOA) prediction by reporting on the cellular response to perturbation. However, the broad application of transcriptomics has yet to fulfill its promise of transforming target elucidation due to challenges in identifying the most relevant, direct responses to target inhibition. We developed an unbiased strategy for MOA prediction, called Perturbation-Specific Transcriptional Mapping (PerSpecTM), in which large-throughput expression profiling of wildtype or hypomorphic mutants, depleted for essential targets, enables a computational strategy to address this challenge. We applied PerSpecTM to perform reference-based MOA prediction based on the principle that similar perturbations, whether chemical or genetic, will elicit similar transcriptional responses. Using this approach, we elucidated the MOAs of three new molecules with activity against Pseudomonas aeruginosa by comparing their expression profiles to those of a reference set of antimicrobial compounds with known MOAs. We also show that transcriptional responses to small molecule inhibition resemble those resulting from genetic depletion of essential targets by CRISPRi by PerSpecTM, demonstrating proof-of-concept that correlations between expression profiles of small molecule and genetic perturbations can facilitate MOA prediction when no chemical entities exist to serve as a reference. Empowered by PerSpecTM, this work lays the foundation for an unbiased, readily scalable, systematic reference-based strategy for MOA elucidation that could transform antibiotic discovery efforts.

Chemical Genetics in C. elegans Identifies Anticancer Mycotoxins Chaetocin and Chetomin as Potent Inducers of a Nuclear Metal Homeostasis Response.

C. elegans numr-1/2 (nuclear-localized metal-responsive) is an identical gene pair encoding a nuclear protein previously shown to be activated by cadmium and disruption of the integrator RNA metabolism complex. We took a chemical genetic approach to further characterize regulation of this novel metal response by screening 41,716 compounds and extracts for numr-1p::GFP activation. The most potent activator was chaetocin, a fungal 3,6-epidithiodiketopiperazine (ETP) with promising anticancer activity. Chaetocin activates numr-1/2 strongly in the alimentary canal but is distinct from metal exposure, because it represses canonical cadmium-responsive metallothionine genes. Chaetocin has diverse targets in cancer cells including thioredoxin reductase, histone lysine methyltransferase, and acetyltransferase p300/CBP; further work is needed to identify the mechanism in C. elegans as genetic disruption and RNAi screening of homologues did not induce numr-1/2 in the alimentary canal and chaetocin did not affect markers of integrator dysfunction. We demonstrate that disulfides in chaetocin and chetomin, a dimeric ETP analog, are required to induce numr-1/2. ETP monomer gliotoxin, despite possessing a disulfide linkage, had almost no effect on numr-1/2, suggesting a dimer requirement. Chetomin inhibits C. elegans growth at low micromolar levels, and loss of numr-1/2 increases sensitivity; C. elegans and Chaetomiaceae fungi inhabit similar environments raising the possibility that numr-1/2 functions as a defense mechanism. There is no direct orthologue of numr-1/2 in humans, but RNaseq suggests that chaetocin affects expression of cellular processes linked to stress response and metal homeostasis in colorectal cancer cells. Our results reveal interactions between metal response gene regulation and ETPs and identify a potential mechanism of resistance to this versatile class of preclinical compounds.

"Multiplexed screen identifies a Pseudomonas aeruginosa -specific small molecule targeting the outer membrane protein OprH and its interaction with LPS".

The surge of antimicrobial resistance threatens efficacy of current antibiotics, particularly against Pseudomonas aeruginosa , a highly resistant gram-negative pathogen. The asymmetric outer membrane (OM) of P. aeruginosa combined with its array of efflux pumps provide a barrier to xenobiotic accumulation, thus making antibiotic discovery challenging. We adapted PROSPECT 1 , a target-based, whole-cell screening strategy, to discover small molecule probes that kill P. aeruginosa mutants depleted for essential proteins localized at the OM. We identified BRD1401, a small molecule that has specific activity against a P. aeruginosa mutant depleted for the essential lipoprotein, OprL. Genetic and chemical biological studies identified that BRD1401 acts by targeting the OM ß-barrel protein OprH to disrupt its interaction with LPS and increase membrane fluidity. Studies with BRD1401 also revealed an interaction between OprL and OprH, directly linking the OM with peptidoglycan. Thus, a whole-cell, multiplexed screen can identify species-specific chemical probes to reveal novel pathogen biology.

Longitudinal natural history studies based on real-world data in rare diseases: Opportunity and a novel approach.

Growing interest in therapeutic development for rare diseases necessitate a systematic approach to the collection and curation of natural history data that can be applied consistently across this group of heterogenous rare diseases. In this study, we discuss the challenges facing natural history studies for leukodystrophies and detail a novel standardized approach to creating a longitudinal natural history study using existing medical records. Prospective studies are uniquely challenging for rare diseases. Delays in diagnosis and overall rarity limit the timely collection of natural history data. When feasible, prospective studies are often cross-sectional rather than longitudinal and are unlikely to capture pre- or early- symptomatic disease trajectories, limiting their utility in characterizing the full natural history of the disease. Therapeutic development in leukodystrophies is subject to these same obstacles. The Global Leukodystrophy Initiative Clinical Trials Network (GLIA-CTN) comprises of a network of research institutions across the United States, supported by a multi-center biorepository protocol, to map the longitudinal clinical course of disease across leukodystrophies. As part of GLIA-CTN, we developed Standard Operating Procedures (SOPs) that delineated all study processes related to staff training, source documentation, and data sharing. Additionally, the SOP detailed the standardized approach to data extraction including diagnosis, clinical presentation, and medical events, such as age at gastrostomy tube placement. The key variables for extraction were selected through face validity, and common electronic case report forms (eCRF) across leukodystrophies were created to collect analyzable data. To enhance the depth of the data, clinical notes are extracted into "original" and "imputed" encounters, with imputed encounter referring to a historic event (e.g., loss of ambulation 3 months prior). Retrospective Functional Assessments were assigned by child neurologists, using a blinded dual-rater approach and score discrepancies were adjudicated by a third rater. Upon completion of extraction, data source verification is performed. Data missingness was evaluated using statistics. The proposed methodology will enable us to leverage existing medical records to address the persistent gap in natural history data within this unique disease group, allow for assessment of clinical trajectory both pre- and post-formal diagnosis, and promote recruitment of larger cohorts.

Characterization of mRNA Lipid Nanoparticles by Electron Density Mapping Reconstruction: X-ray Scattering with Density from Solution Scattering (DENSS) Algorithm.

PURPOSE: This study aimed to test the feasibility of using Small Angle X-ray Scattering (SAXS) coupled with Density from Solution Scattering (DENSS) algorithm to characterize the internal architecture of messenger RNA-containing lipid nanoparticles (mRNA-LNPs). METHODS: The DENSS algorithm was employed to construct a three-dimensional model of average individual mRNA-LNP. The reconstructed models were cross validated with cryogenic transmission electron microscopy (cryo-TEM), and dynamic light scattering (DLS) to assess size, morphology, and internal structure. RESULTS: Cryo-TEM and DLS complemented SAXS, revealed a core-shell mRNA-LNP structure with electron-rich mRNA-rich region at the core, surrounded by lipids. The reconstructed model, utilizing the DENSS algorithm, effectively distinguishes mRNA and lipids via electron density mapping. Notably, DENSS accurately models the morphology of the mRNA-LNPs as an ellipsoidal shape with a "bleb" architecture or a two-compartment structure with contrasting electron densities, corresponding to mRNA-filled and empty lipid compartments, respectively. Finally, subtle changes in the LNP structure after three freeze-thaw cycles were detected by SAXS, demonstrating an increase in radius of gyration (Rg) associated with mRNA leakage. CONCLUSION: Analyzing SAXS profiles based on DENSS algorithm to yield a reconstructed electron density based three-dimensional model can be a useful physicochemical characterization method in the toolbox to study mRNA-LNPs and facilitate their development.

Prelacteal feeding is not associated with infant size at 3 months in rural Bangladesh: a prospective cohort study.

BACKGROUND: Early and exclusive breastfeeding may reduce neonatal and post-neonatal mortality in low-resource settings. However, prelacteal feeding (PLF), the practice of giving food or liquid before breastfeeding is established, is still a barrier to optimal breastfeeding practices in many South Asian countries. We used a prospective cohort study to assess the association between feeding non-breastmilk food or liquid in the first three days of life and infant size at 3-5 months of age. METHODS: The analysis used data from 3,332 mother-infant pairs enrolled in a randomized controlled trial in northwestern rural Bangladesh conducted from 2018 to 2019. Trained interviewers visited women in their households during pregnancy to collect sociodemographic data. Project staff were notified of a birth by telephone and interviewers visited the home within approximately three days and three months post-partum. At each visit, interviewers collected data on breastfeeding practices and anthropometric measures. Infant length and weight measurements were used to produce length-for-age (LAZ), weight-for-age (WAZ), and weight-for-length (WLZ) Z-scores. We used multiple linear regression to assess the association between anthropometric indices and PLF practices, controlling for household wealth, maternal age, weight, education, occupation, and infant age, sex, and neonatal sizes. RESULTS: The prevalence of PLF was 23%. Compared to infants who did not receive PLF, infants who received PLF may have a higher LAZ (Mean difference (MD) = 0.02 [95% CI: -0.04, 0.08]) score, a lower WLZ (MD=-0.06 [95% CI: -0.15, 0.03]) score, and a lower WAZ (MD=-0.02 [95% CI: -0.08, 0.05]) score at 3-5 months of age, but none of the differences were statistically significant. In the adjusted model, female sex, larger size during the neonatal period, higher maternal education, and wealthier households were associated with larger infant size. CONCLUSION: PLF was a common practice in this setting. Although no association between PLF and infant growth was identified, we cannot ignore the potential harm posed by PLF. Future studies could assess infant size at an earlier time point, such as 1-month postpartum, or use longitudinal data to assess more subtle differences in growth trajectories with PLF. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03683667 and NCT02909179.

The Trimeric Autotransporter Adhesin EmaA and Infective Endocarditis.

Infective endocarditis (IE), a disease of the endocardial surface of the heart, is usually of bacterial origin and disproportionally affects individuals with underlying structural heart disease. Although IE is typically associated with Gram-positive bacteria, a minority of cases are caused by a group of Gram-negative species referred to as the HACEK group. These species, classically associated with the oral cavity, consist of bacteria from the genera Haemophilus (excluding Haemophilus influenzae), Aggregatibacter, Cardiobacterium, Eikenella, and Kingella. Aggregatibacter actinomycetemcomitans, a bacterium of the Pasteurellaceae family, is classically associated with Aggressive Periodontitis and is also concomitant with the chronic form of the disease. Bacterial colonization of the oral cavity serves as a reservoir for infection at distal body sites via hematological spreading. A. actinomycetemcomitans adheres to and causes disease at multiple physiologic niches using a diverse array of bacterial cell surface structures, which include both fimbrial and nonfimbrial adhesins. The nonfimbrial adhesin EmaA (extracellular matrix binding protein adhesin A), which displays sequence heterogeneity dependent on the serotype of the bacterium, has been identified as a virulence determinant in the initiation of IE. In this chapter, we will discuss the known biochemical, molecular, and structural aspects of this protein, including its interactions with extracellular matrix components and how this multifunctional adhesin may contribute to the pathogenicity of A. actinomycetemcomitans.

Allometric scaling for left ventricular mass and geometry in male and female athletes of mixed and endurance sports.

BACKGROUND: The athlete's heart (AH) defines the phenotypical changes that occur in response to chronic exercise training. Echocardiographic assessment of the AH is used to calculate LV mass (LVM) and determine chamber geometry. This is, however, interpreted using standard linear (ratiometric) scaling to body surface area (BSA) whereas allometric scaling is now widely recommended. This study (1) determined whether ratiometric scaling of LVM to BSA (LVMiratio) provides a size-independent index in young and veteran athletes of mixed and endurance sports (MES), and (2) calculated size-independent beta exponents for allometrically derived (LVMiallo) to BSA and (3) describes the physiological range of LVMiallo and the classifications of LV geometry. METHODS: 1373 MES athletes consisting of young (< 35 years old) (males n = 699 and females n = 127) and veteran (> 35 years old) (males n = 327 and females n = 220) were included in the study. LVMiratio was calculated as per standard scaling and sex-specific LVMiallo were derived from the population. Cut-offs were defined and geometry was classified according to the new exponents and relative wall thickness. RESULTS: LVMiratio did not produce a size independent index. When tested across the age range the following indexes LVMi/BSA0.7663 and LVMi/BSA0.52, for males and females respectively, were size independent (r = 0.012; P = 0.7 and r = 0.003; P = 0.920). Physiological cut-offs for LVMiallo were 135 g/(m2)0.7663 in male athletes and 121 g/(m2)0.52 in female athletes. Concentric remodelling / hypertrophy was present in 3% and 0% of young male and female athletes and 24% and 17% of veteran male and female athletes, respectively. Eccentric hypertrophy was observed in 8% and 6% of young male and female athletes and 9% and 11% of veteran male and female athletes, respectively. CONCLUSION: In a large cohort of young and veteran male and female MES athletes, LVMiratio to BSA is not size independent. Sex-specific LVMiallo to BSA with LVMi/BSA0.77 and LVMi/BSA0.52 for male and female athletes respectively can be applied across the age-range. Population-based cut-offs of LVMiallo provided a physiological range demonstrating a predominance for normal geometry in all athlete groups with a greater percentage of concentric remodelling/hypertrophy occurring in veteran male and female athletes.

Neonatal mortality risk of vulnerable newborns by fine stratum of gestational age and birthweight for 230 679 live births in nine low- and middle-income countries, 2000-2017.

OBJECTIVE: To describe the mortality risks by fine strata of gestational age and birthweight among 230 679 live births in nine low- and middle-income countries (LMICs) from 2000 to 2017. DESIGN: Descriptive multi-country secondary data analysis. SETTING: Nine LMICs in sub-Saharan Africa, Southern and Eastern Asia, and Latin America. POPULATION: Liveborn infants from 15 population-based cohorts. METHODS: Subnational, population-based studies with high-quality birth outcome data were invited to join the Vulnerable Newborn Measurement Collaboration. All studies included birthweight, gestational age measured by ultrasound or last menstrual period, infant sex and neonatal survival. We defined adequate birthweight as 2500-3999 g (reference category), macrosomia as ≥4000 g, moderate low as 1500-2499 g and very low birthweight as <1500 g. We analysed fine strata classifications of preterm, term and post-term: ≥42+0 , 39+0 -41+6 (reference category), 37+0 -38+6 , 34+0 -36+6 ,34+0 -36+6 ,32+0 -33+6 , 30+0 -31+6 , 28+0 -29+6 and less than 28 weeks. MAIN OUTCOME MEASURES: Median and interquartile ranges by study for neonatal mortality rates (NMR) and relative risks (RR). We also performed meta-analysis for the relative mortality risks with 95% confidence intervals (CIs) by the fine categories, stratified by regional study setting (sub-Saharan Africa and Southern Asia) and study-level NMR (≤25 versus >25 neonatal deaths per 1000 live births). RESULTS: We found a dose-response relationship between lower gestational ages and birthweights with increasing neonatal mortality risks. The highest NMR and RR were among preterm babies born at <28 weeks (median NMR 359.2 per 1000 live births; RR 18.0, 95% CI 8.6-37.6) and very low birthweight (462.8 per 1000 live births; RR 43.4, 95% CI 29.5-63.9). We found no statistically significant neonatal mortality risk for macrosomia (RR 1.1, 95% CI 0.6-3.0) but a statistically significant risk for all preterm babies, post-term babies (RR 1.3, 95% CI 1.1-1.5) and babies born at 370 -386 weeks (RR 1.2, 95% CI 1.0-1.4). There were no statistically significant differences by region or underlying neonatal mortality. CONCLUSIONS: In addition to tracking vulnerable newborn types, monitoring finer categories of birthweight and gestational age will allow for better understanding of the predictors, interventions and health outcomes for vulnerable newborns. It is imperative that all newborns from live births and stillbirths have an accurate recorded weight and gestational age to track maternal and neonatal health and optimise prevention and care of vulnerable newborns.