Isolation and Characterization of Extracellular Vesicles to Activate Retina Regeneration.

Mammals do not possess the ability to spontaneously repair or regenerate damaged retinal tissue. In contrast to teleost fish which are capable of retina regeneration through the action of Müller glia, mammals undergo a process of reactive gliosis and scarring that inhibits replacement of lost neurons. Thus, it is important to discover novel methods for stimulating mammalian Müller glia to dedifferentiate and produce progenitor cells that can replace lost retinal neurons. Inducing an endogenous regenerative pathway mediated by Müller glia would provide an attractive alternative to stem cell injections or gene therapy approaches. Extracellular vesicles (EVs) are now recognized to serve as a novel form of cell-cell communication through the transfer of cargo from donor to recipient cells or by the activation of signaling cascades in recipient cells. EVs have been shown to promote proliferation and regeneration raising the possibility that delivery of EVs could be a viable treatment for visual disorders. Here, we provide protocols to isolate EVs for use in retina regeneration experiments.

Cardiac Troponin to Adjudicate Subclinical Heart Failure in Diabetic Patients and a Murine Model of Metabolic Syndrome.

BACKGROUND: Cardiovascular disease, kidney health, and metabolic disease (CKM) syndrome is associated with significant morbidity and mortality, particularly from congestive heart failure (CHF). Guidelines recommend measurement of cardiac troponin (cTn) to identify subclinical heart failure (HF) in diabetics/CKM. However, appropriate thresholds and the impact from routine screening have not been elucidated. METHODS: cTnI was assessed using the Abbott high sensitivity (hs)-cTnI assay in outpatients with physician-ordered hemoglobin A1c (Hb A1c) and associated with cardiac comorbidities/diagnoses, demographics, and estimated glomerular filtration rate (eGFR). Risk thresholds used in CKM staging guidelines of >10 and >12 ng/L for females and males, respectively, were used. Multivariate logistic regression was applied. hs-cTnI was assessed in a high-fat-diet induced murine model of obesity and diabetes. RESULTS: Of 1304 patients, 8.0% females and 15.7% males had cTnI concentrations above the risk thresholds. Thirty-one (4.2%) females and 23 (4.1%) males had cTnI above the sex-specific 99% upper reference limit. A correlation between hs-cTnI and Hb A1c (R = 0.2) and eGFR (R = -0.5) was observed. hs-cTnI concentrations increased stepwise based on A1C of <5.7% (median = 1.5, IQR:1.3-1.8), 5.7%-6.4% (2.1, 2.0-2.4), 6.5%-8.0% (2.8, 2.5-3.2), and >8% (2.8, 2.2-4.3). Male sex (P < 0.001), eGFR (P < 0.001), and CHF (P = 0.004) predicted elevated hs-cTnI. Obese and diabetic mice had increased hs-cTnI (7.3 ng/L, 4.2-10.4) relative to chow-fed mice (2.6 ng/L, 1.3-3.8). CONCLUSION: A high proportion of outpatients with diabetes meet criteria for subclinical HF using hs-cTnI measurements. Glucose control is independently associated with elevated cTnI, a finding replicated in a murine model of metabolic syndrome.

Sex differences in the roles of nicotine use and puberty on youth C-reactive protein levels: Effects above and beyond adversity.

Inflammation likely mediates associations between nicotine use and negative health outcomes. Sex differences have been observed in nicotine use-inflammation links, and physiological processes during puberty might allow for these differences to arise. In this cross-sectional study of 498 youth (ages 8-13, 52% girls, 77% with history of child maltreatment (CM) investigation), sex-differentiated associations between self-reported nicotine use and high-sensitivity C-reactive protein (hs-CRP) were explored. Additionally, self-reported pubertal stage was investigated as a moderator of such nicotine use-hs-CRP links. Hierarchical generalized estimating equation models were adjusted for a wide range of adversity effects: CM investigation history derived from state records, self- and caregiver-report of traumatic life events, adversity-related demographic risk factors (i.e., identification with historically marginalized racial and ethnic groups, household income), and other characteristics that may influence the variables of interest (e.g., medication use, age, body mass index). Nicotine use had a negative main effect on hs-CRP among boys (ß = -0.50, p = 0.02), and pubertal stage did not moderate this association (ß = 0.06, p = 0.71). In contrast, pubertal stage moderated the association between nicotine use and hs-CRP among girls (ß = 0.48, p = 0.02) such that a positive association between nicotine use and hs-CRP levels was stronger at more advanced pubertal stages (ß = 0.45, SE = 0.21, 95% CI [0.03, 0.87]). Findings suggest that puberty may influence the effect of nicotine on inflammation in sex-differentiated ways and have implications for timing of prevention and treatment efforts geared toward reducing nicotine use and subsequent inflammation-related health risk among youth.

Transmission potential of Streptococcus pyogenes during a controlled human infection trial of pharyngitis.

Controlled human infection (CHI) models can provide insights into transmission of pathogens such as Streptococcus pyogenes (Strep A). As part of the Controlled Human Infection with Penicillin for Streptococcus pyogenes (CHIPS) trial, we explored the potential for transmission among participants deliberately infected with the Strep A emm75 strain. Three approaches to understanding transmission were employed: the use of agar settle plates to capture possible droplet or airborne spread of Strep A; measurement of distance droplets could spread during conversation; and environmental swabbing of high-touch items to detect Strep A on surfaces. Of the 60 (27%) CHIPS trial participants across five cohorts, 16 were enrolled in this sub-study; availability of study staff was the primary reason for selection. In total, 189 plates and 260 swabs were collected. Strep A was grown on one settle plate from a participant on the second day, using plates placed 30 cm away. This participant received the placebo dose of penicillin and had met the primary endpoint of pharyngitis. Whole-genome sequencing identified this to be the challenge strain. Strep A was not detected on any swabs. In this small sample of CHI participants, we did not find evidence of Strep A transmission by the airborne route or fomites, and just one instance of droplet spread while acutely symptomatic with streptococcal pharyngitis. Although these experiments provide evidence of minimal transmission within controlled clinical settings, greater efforts are required to explore Strep A transmission in naturalistic settings.IMPORTANCEStreptococcus pyogenes remains a significant driver of morbidity and mortality, particularly in under-resourced settings. Understanding the transmission modalities of this pathogen is essential to ensuring the success of prevention methods. This proposed paper presents a nascent attempt to determine the transmission potential of Streptococcus pyogenes nested within a larger controlled human infection model.

Hepatocellular Carcinoma Etiology Drives Survival Outcomes: A Population-Based Analysis.

BACKGROUND: Previous survival studies on hepatocellular carcinoma (HCC) by etiology are limited to hospital-based series, restricted cohorts, and monolithic etiological categories. We studied population-based survival by seven mutually exclusive HCC etiologic groups-standalone hepatitis-C virus (HCV), hepatitis-B virus (HBV), alcohol-related liver disease (ALD), non-alcoholic fatty liver disease (NAFLD), and dual etiology HCV&HBV, HCV&ALD, and HBV&ALD-accounting for clinical and socio-demographic characteristics. METHODS: All HCC cases diagnosed during 2005-2018 from the Florida Cancer Registry were linked for etiology using statewide discharge and viral hepatitis data. We performed cause-specific survival analysis including Cox regression for the matched 15,616 cases by HCC etiology. RESULTS: The leading etiology was HCV only (n=4,983; 31.9%); the leading dual etiology was HCV&ALD (n=2,552; 16.3%). Five-year adjusted survival was low, 17.6% overall and <22% across all HCC etiologies; yet ALD-related etiologies [ALD only (14.4%; 95%CI:12.7-16.0), HCV&ALD (10.2%; 95%CI:8.7-11.7), HBV&ALD (8.2%; 95%CI:2.2-14.1)] showed lower survival than non-ALD causes-HCV only, HBV only, and NAFLD only. After adjustment for clinical and socio-demographic covariates, ALD- and HBV&ALD-HCC had 1.20 (95%CI:1.13-1.27) and 1.28 (95%CI:1.06-1.54) times higher risk of death, compared to those with HCV only-HCC. CONCLUSIONS: ALD only and dual etiologies involving ALD show worse prognosis for HCC, compared to viral etiology alone. To increase survival, improved screening and treatment are needed for patients with multiple HCC risk factors. IMPACT: Understanding US disparities in HCC survival by etiology can help guide the identification of etiologically specific biomarkers and potential therapeutic targets and inform public health measures.

Hepatitis a vaccine immunogenicity and boostability in adults receiving immunosuppressive therapy and adults living with HIV: a prospective single-Centre cohort study.

INTRODUCTION: Hepatitis A (hepA) vaccination is highly immunogenic in healthy individuals, however there is uncertainty about the immunogenicity in immunocompromised populations (ICPs). METHODS: In this prospective cohort study, people living with HIV (PLWH), patients on immunosuppressive mono- and combination therapy, and controls received two hepA vaccine doses at months 0 and 6-12, or three combined hepA/B vaccine doses at months 0, 1 and 6-12. Antibody levels were measured before and at different time-points post-vaccination (T2, 6, 8, 12 months). The primary endpoint was the seroconversion rate (SCR) at T8, defined as hepA antibodies ≥20 mIU/ml. To assess boostability, an additional vaccine dose was administered 1-5 years after T12 in those with antibodies < 50 mIU/ml, with antibody measurements before and seven days after the booster dose. RESULTS: We included 150 participants. At T2 SCRs ranged between 35-58% in ICPs versus 94% in controls. Among PLWH, patients on monotherapy, combination therapy and controls SCRs at T8 were 33/34 (97%), 32/34 (94%), 25/30 (83%) and 28/28 (100%) respectively. The booster dose resulted in 71% additional seroconversion (17/24), with only patients using combination therapy not responding. CONCLUSIONS: HepA vaccination is highly immunogenic in virologically suppressed PLWH and patients on immunosuppressive monotherapy, with SCRs after the complete hepA vaccination schedule similar to controls and adequate booster responses in case of waning immunity. However, patients using immunosuppressive combination therapy as well as all ICPs who did not receive the complete hepA vaccination schedule, are at risk of non-response to vaccination and post-vaccination antibody measurements are recommended.

Rethinking the residual approach: Leveraging machine learning to operationalize cognitive resilience in Alzheimer's disease.

Cognitive resilience describes the phenomenon of individuals evading cognitive decline despite prominent Alzheimer's disease neuropathology. Operationalization and measurement of this latent construct is non-trivial as it cannot be directly observed. The residual approach has been widely applied to estimate CR, where the degree of resilience is estimated through a linear model's residuals. We demonstrate that this approach makes specific, uncontrollable assumptions and likely leads to biased and erroneous resilience estimates. We propose an alternative strategy which overcomes the standard approach's limitations using machine learning principles. Our proposed approach makes fewer assumptions about the data and construct to be measured and achieves better estimation accuracy on simulated ground-truth data.

A systematic review of medical practitioners' retention and application of basic sciences to clinical practice.

BACKGROUND: Medical education offers the foundational base for future healthcare professionals, with basic sciences playing a pivotal role in providing essential knowledge and skills for clinical practice. However, the long-term retention and application of this knowledge in clinical practice remain a significant challenge. This systematic review synthesised global evidence from diverse studies on the short / long-term retention and clinical application of basic sciences among medical doctors. METHODS: A comprehensive search was conducted across six databases, including Web of Science, Scopus, Medline, CINAHL, Emcare, and Informit. The review included studies that encompassed a variety of study designs, participant groups, and educational interventions. The Quality Assessment with Diverse Studies (QuADS) tool was utilised to assess the quality of the reviewed studies. RESULTS: A total of 10 studies were included in the review. The findings revealed that rehearsals significantly optimise the retention of basic science knowledge among medical practitioners. Retention varied by discipline, with medical practitioners retaining more knowledge in anatomy (mean scores ranging from 45.0 to 82.9%), while microbiology had the lowest retention score (39.1%). Factors influencing retention included age, gender, and curriculum type. Educational interventions such as targeted courses, integration of basic sciences with clinical skills, generative retrieval and continuous quality improvement in the curriculum were found to enhance both knowledge retention and clinical reasoning. The concept of 'encapsulated knowledge' demonstrates that integrated basic science knowledge helps in synthesising clinical presentations, reducing the need for detailed recall as clinical experience increases. The reviewed studies primarily involved interns and surgeons, leaving a significant gap in research for specialties like internal medicine and primary care/ general practice. CONCLUSION: Detailed retention of basic science knowledge may diminish over time; however, the conceptual framework remains essential for ongoing learning and clinical reasoning. This review's findings highlight the need for specialised educational interventions to improve long-term retention. Continuous professional development and targeted educational techniques are vital for maintaining clinical competence and applying basic science knowledge effectively throughout a medical career. Further research is needed to address gaps in specialty-specific knowledge application and the impact of different instructional methods.

An Electrolytic Elemental Iron Powder Effectively Regenerates Hemoglobin in Anemic Rats and Is Relatively Well Absorbed When Compared to Ferrous Sulfate Monohydrate.

Elemental iron powders are used as food fortificants to reduce the incidence of iron deficiency anemia. However, many commercially available iron powders are relatively untested in vivo. The purpose of this study was to determine the hemoglobin regeneration efficiency (HRE) and relative iron bioavailability (RBV) of an electrolytic elemental iron powder (EIP), by treating anemic rats with 14 d iron repletion diets fortified with four different concentrations (12, 24, 36, or 48 mg iron/kg diet) of EIP and bakery-grade ferrous sulfate monohydrate (FS; FeSO4•H2O), or no added iron (control); n = 9-12/group. The HRE of FS was significantly higher (p ≤ 0.05) than EIP at each concentration of dietary iron tested. For EIP, the HREs (ratios) of diets containing 12, 24, 36, and 48 mg iron/kg were 0.356, 0.205, 0.197, and 0.163, respectively. For both EIP and FS, HRE was inversely associated with increasing dietary iron. The RBVs (%) of iron from EIP in diets at 12, 24, 36, and 48 mg iron/kg as compared to FS were 64.5, 59.1, 50.6, and 54.3%, respectively. Overall, findings show that at the concentrations of iron tested, EIP has RBVs greater than 50% and is an effective fortification agent to replenish hemoglobin and correct iron deficiency anemia.

Suppression of neuronal AMPKß2 isoform impairs recognition memory and synaptic plasticity.

AMP-activated protein kinase (AMPK) is an αßγ heterotrimer protein kinase that functions as a molecular sensor to maintain energy homeostasis. Accumulating evidence suggests a role of AMPK signaling in the regulation of synaptic plasticity and cognitive function; however, isoform-specific roles of AMPK in the central nervous system (CNS) remain elusive. Regulation of the AMPK activities has focused on the manipulation of the α or γ subunit. Meanwhile, accumulating evidence indicates that the ß subunit is critical for sensing nutrients such as fatty acids and glycogen to control AMPK activity. Here, we generated transgenic mice with conditional suppression of either AMPKß1 or ß2 in neurons and characterized potential isoform-specific roles of AMPKß in cognitive function and underlying mechanisms. We found that AMPKß2 (but not ß1) suppression resulted in impaired recognition memory, reduced hippocampal synaptic plasticity, and altered structure of hippocampal postsynaptic densities and dendritic spines. Our study implicates a role for the AMPKß2 isoform in the regulation of synaptic and cognitive function.

A national survey of current rehabilitation service provisions for people living with chronic kidney disease in the UK: implications for policy and practice.

BACKGROUND: National guidance recognises the key role of rehabilitation in improving outcomes for people living with chronic kidney disease. Implementation of this guidance is reliant upon an adequate and skilled rehabilitation workforce. Data relating to this is currently lacking within the UK. This survey aimed to identify variations and good practices in kidney physiotherapy (PT), occupational therapy (OT) and clinical exercise physiologist (CEP) provision; and to understand barriers to implementation. METHODS: An online survey was sent to all 87 UK kidney units between June 2022 and January 2023. Data was collected on the provision of therapy services, barriers to service provision and responses to the COVID-19 pandemic. The quantitative survey was analysed using descriptive statistics. Free-text responses were explored using reflexive thematic analysis. RESULTS: Forty-five units (52%) responded. Seventeen (38%) units reported having a PT and 15 (33%) an OT with a specialist kidney role; one unit (7%) had access to a CEP. Thirty units (67%) offered inpatient therapy services, ten (22%) outpatient therapy clinics, six (13%) intradialytic exercise, six (13%) symptom management and three (7%) outpatient rehabilitation. Qualitative data revealed lack of money/funding and time (both n = 35, 85% and n = 34, 83% respectively) were the main barriers to delivering kidney-specific therapy. Responders saw an increase in the complexity of their caseload, a reduction in staffing levels and consequently, service provision during the COVID-19 pandemic. Exemplars of innovative service delivery, including hybrid digital and remote services, were viewed as positive responses to the COVID-19 pandemic. CONCLUSION: Despite clear evidence of the benefits of rehabilitation, across the UK, there remains limited and variable access to kidney-specific therapy services. Equitable access to kidney-specific rehabilitation services is urgently required to support people to 'live well' with kidney disease.

The impact of ammonia on particle formation in the Asian Tropopause Aerosol Layer.

During summer, ammonia emissions in Southeast Asia influence air pollution and cloud formation. Convective transport by the South Asian monsoon carries these pollutant air masses into the upper troposphere and lower stratosphere (UTLS), where they accumulate under anticyclonic flow conditions. This air mass accumulation is thought to contribute to particle formation and the development of the Asian Tropopause Aerosol Layer (ATAL). Despite the known influence of ammonia and particulate ammonium on air pollution, a comprehensive understanding of the ATAL is lacking. In this modelling study, the influence of ammonia on particle formation is assessed with emphasis on the ATAL. We use the EMAC chemistry-climate model, incorporating new particle formation parameterisations derived from experiments at the CERN CLOUD chamber. Our diurnal cycle analysis confirms that new particle formation mainly occurs during daylight, with a 10-fold enhancement in rate. This increase is prominent in the South Asian monsoon UTLS, where deep convection introduces high ammonia levels from the boundary layer, compared to a baseline scenario without ammonia. Our model simulations reveal that this ammonia-driven particle formation and growth contributes to an increase of up to 80% in cloud condensation nuclei (CCN) concentrations at cloud-forming heights in the South Asian monsoon region. We find that ammonia profoundly influences the aerosol mass and composition in the ATAL through particle growth, as indicated by an order of magnitude increase in nitrate levels linked to ammonia emissions. However, the effect of ammonia-driven new particle formation on aerosol mass in the ATAL is relatively small. Ammonia emissions enhance the regional aerosol optical depth (AOD) for shortwave solar radiation by up to 70%. We conclude that ammonia has a pronounced effect on the ATAL development, composition, the regional AOD, and CCN concentrations.

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A Systematic Analysis of Read-Across Adaptations in Testing Proposal Evaluations by the European Chemicals Agency.

An important element of the European Union's "Registration, Evaluation, Authorisation and Restriction of Chemicals" (REACH) regulation is the evaluation by the European Chemicals Agency (ECHA) of testing proposals submitted by the registrants to address data gaps in standard REACH information requirements. The registrants may propose adaptations, and ECHA evaluates the reasoning and issues a written decision. Read-across is a common adaptation type, yet it is widely assumed that ECHA often does not agree that the justifications are adequate to waive standard testing requirements. From 2008 to August 2023, a total of 2,630 Testing Proposals were submitted to ECHA; of these, 1,538 had published decisions that were systematically evaluated in this study. Each document was manually reviewed, and information extracted for further analyses. Read-across hypotheses were standardized into 17 assessment elements (AEs); each submission was classified as to the AEs relied upon by the registrants and by ECHA. Data was analyzed for patterns and associations. Testing Proposal Evaluations (TPEs) with adaptations comprised 23% (353) of the total; analogue (168) or group (136) read-across adaptations were most common. Of 304 read-across-containing TPEs, 49% were accepted; the odds of acceptance were significantly greater for group read-across submissions. The data was analyzed by Annex (i.e., tonnage), test guideline study, read-across hypothesis AEs, as well as target and source substance types and their structural similarity. While most ECHA decisions with both positive and negative decisions on whether the proposed read-across was adequate were context-specific, a number of significant associations were identified that influence the odds of acceptance. Overall, this analysis provides an unbiased overview of 15 years of experience with testing proposal-specific read-across adaptations by both registrants and ECHA. These data will inform future submissions as they identify most critical AEs to increase the odds of read-across acceptance.

An RNA binding regulatory cascade controls the switch from proliferation to differentiation in the Drosophila male germ line stem cell lineage.

The switch from precursor cell proliferation to onset of differentiation in adult stem cell lineages must be carefully regulated to produce sufficient progeny to maintain and repair tissues, yet prevent overproliferation that may enable oncogenesis. In the Drosophila male germ cell lineage, spermatogonia produced by germ line stem cells undergo a limited number of transit amplifying mitotic divisions before switching to the spermatocyte program that sets up meiosis and eventual spermatid differentiation. The number of transit amplifying divisions is set by accumulation of the bag-of-marbles (Bam) protein to a critical threshold. In bam mutants, spermatogonia proliferate through several extra rounds of mitosis then die without becoming spermatocytes. Here we show that the key role of Bam for the mitosis to differentiation switch is repressing expression of Held Out Wings ( how ), homolog of mammalian Quaking. Knock down of how in germ cells was sufficient to allow spermatogonia mutant for bam or its partner benign gonial cell neoplasm ( bgcn ) to differentiate, while forced expression of nuclear-targeted How protein in spermatogonia wild-type for bam resulted in continued proliferation at the expense of differentiation. Our findings suggest that Bam targets how RNA for degradation by acting as an adapter to recruit the CCR4-NOT deadenylation complex via binding its subunit, Caf40. As How is itself an RNA binding protein with roles in RNA processing, our findings reveal that the switch from proliferation to meiosis and differentiation in the Drosophila male germ line adult stem cell lineage is regulated by a cascade of RNA-binding proteins.

5-Fluorouracil treatment represses pseudouridine-containing miRNA export into extracellular vesicles.

5-Fluorouracil (5-FU) has been used for chemotherapy for colorectal and other cancers for over 50 years. The prevailing view of its mechanism of action is inhibition of thymidine synthase leading to defects in DNA replication and repair. However, 5-FU is also incorporated into RNA causing defects in RNA metabolism, inhibition of pseudouridine modification, and altered ribosome function. We examined the impact of 5-FU on post-transcriptional small RNA modifications (PTxMs) and the expression and export of RNA into small extracellular vesicles (sEVs). EVs are secreted by all cells and contain a variety of proteins and RNAs that can function in cell-cell communication. We found that treatment of colorectal cancer (CRC) cells with 5-FU represses sEV export of miRNA and snRNA-derived RNAs, but promotes export of snoRNA-derived RNAs. Strikingly, 5-FU treatment significantly decreased the levels of pseudouridine on both cellular and sEV small RNA profiles. In contrast, 5-FU exposure led to increased levels of cellular small RNAs containing a variety of methyl-modified bases. These unexpected findings show that 5-FU exposure leads to altered RNA expression, base modification, and aberrant trafficking and localization of small RNAs.

HYDIN variants cause primary ciliary dyskinesia in the Finnish population.

INTRODUCTION: Primary ciliary dyskinesia (PCD) is a rare genetic disorder characterized by chronic respiratory tract infections and in some cases laterality defects and infertility. The symptoms of PCD are caused by malfunction of motile cilia, hair-like organelles protruding out of the cell. Thus far, disease causing variants in over 50 genes have been identified and these variants explain around 70% of all known cases. Population specific genetics underlying PCD has been reported highlighting the importance of characterizing gene variants in different populations for development of gene-based diagnostics and management. METHODS: Whole exome sequencing was used to identify disease causing variants in Finnish PCD cohort. The effect of the identified HYDIN variants on cilia structure and function was confirmed by high-speed video analysis, immunofluorescence and electron tomography. RESULTS: In this study, we identified three Finnish PCD patients carrying homozygous loss-of-function variants and one patient with compound heterozygous variants within HYDIN. The functional studies showed defects in the axonemal central pair complex. All patients had clinical PCD symptoms including chronic wet cough and recurrent airway infections, associated with mostly static airway cilia. CONCLUSION: Our results are consistent with the previously identified important role of HYDIN in the axonemal central pair complex and improve specific diagnostics of PCD in different national populations.

DNAm scores for serum GDF15 and NT-proBNP levels associate with a range of traits affecting the body and brain.

BACKGROUND: Plasma growth differentiation factor 15 (GDF15) and N-terminal proB-type natriuretic peptide (NT-proBNP) are cardiovascular biomarkers that associate with a range of diseases. Epigenetic scores (EpiScores) for GDF15 and NT-proBNP may provide new routes for risk stratification. RESULTS: In the Generation Scotland cohort (N ≥ 16,963), GDF15 levels were associated with incident dementia, ischaemic stroke and type 2 diabetes, whereas NT-proBNP levels were associated with incident ischaemic heart disease, ischaemic stroke and type 2 diabetes (all PFDR < 0.05). Bayesian epigenome-wide association studies (EWAS) identified 12 and 4 DNA methylation (DNAm) CpG sites associated (Posterior Inclusion Probability [PIP] > 95%) with levels of GDF15 and NT-proBNP, respectively. EpiScores for GDF15 and NT-proBNP were trained in a subset of the population. The GDF15 EpiScore replicated protein associations with incident dementia, type 2 diabetes and ischaemic stroke in the Generation Scotland test set (hazard ratios (HR) range 1.36-1.41, PFDR < 0.05). The EpiScore for NT-proBNP replicated the protein association with type 2 diabetes, but failed to replicate an association with ischaemic stroke. EpiScores explained comparable variance in protein levels across both the Generation Scotland test set and the external LBC1936 test cohort (R2 range of 5.7-12.2%). In LBC1936, both EpiScores were associated with indicators of poorer brain health. Neither EpiScore was associated with incident dementia in the LBC1936 population. CONCLUSIONS: EpiScores for serum levels of GDF15 and Nt-proBNP associate with body and brain health traits. These EpiScores are provided as potential tools for disease risk stratification.

Practice Patterns of Cardiovascular Magnetic Resonance Use in the Diagnosis of Pediatric Myocarditis: A Survey-Based Study.

BACKGROUND: Cardiovascular magnetic resonance (CMR) is used to diagnose myocarditis in adults and children based on the original Lake Louise Criteria (LLC) and more recently the revised LLC. The major change included in the revised LLC was the incorporation of parametric mapping, which significantly increases the sensitivity and specificity of diagnosis. Subsequently, scientific statements have recommended the use of parametric mapping in the diagnosis of myocarditis in children. However, there are some challenges to parametric mapping that are unique to the pediatric population. Our goal is to characterize clinical CMR and parametric mapping practice patterns for diagnosis of myocarditis in pediatric centers. METHODS: The Cardiovascular Magnetic Resonance Evaluation in Return to Athletes for Myocarditis in COVID-19 and Immunization Consortium created a REDCap survey to evaluate clinical practice patterns for diagnosis of myocarditis in pediatrics. This survey was distributed to the Society for Cardiovascular Magnetic Resonance community. RESULTS: 59 responses from 51 centers were received, with only one response from each center being utilized. Only 35% of centers (37% of North America, 31% of international) reported using CMR routinely in all patients with a suspicion for myocarditis. Diagnostic uncertainty was noted as the most important reason for CMR, while cost was noted as the least important consideration. The majority of centers reported using the revised LLC (37/51, 72%) compared to original LLC (7/51, 14%) or a hybrid criteria (6/51, 12%). When looking at the use of parametric mapping, only 5/47 (11%) for T1 mapping and 11/49 (22%) for T2 mapping reported having scanner-specific pediatric normative data. CONCLUSION: Routine CMR imaging for diagnosis of myocarditis in pediatrics is infrequently performed at surveyed centers despite the focus on a group of non-invasive cardiac imagers. While the majority reported using parametric mapping, few centers reporting having pediatric scanner-specific normative data. This highlights an important gap in the utilization of CMR that may aid in the diagnosis of myocardial disease.

Circulating apoE4 protein levels from dried blood spots predict cognitive function in a large population-based survey setting.

INTRODUCTION: The apolipoprotein E (APOE) ε4 allele carries risk for cognitive impairment, but whether the level of circulating apoE4 protein in carriers affects cognition is unclear, as is how health and lifestyle impact circulating apoE4 levels. METHODS: We assayed apoE4 protein levels in dried blood spots of 12,532 adults aged 50+. Regression analyses tested the likelihood of cognitive impairment between groups and within those with detected apoE4 protein. Predictors of circulating apoE4 were assessed. RESULTS: We detected protein binding that indicates the presence of an APOE ε4 allele in 28.4% of this group. This group was more likely to have cognitive impairment, and this risk increases with age. However, higher apoE4 levels were associated with less likelihood of cognitive impairment within this group. Antihypertensive medication predicted apoE4 protein levels. DISCUSSION: The apoE4 isoform is associated with a deficient protein and worse cognition. This association is modulated by the level of circulating apoE4 protein in ε4 carriers. HIGHLIGHTS: An assay to quantify apoE4 levels from dried blood spot samples was applied. The apoE4 protein was detected as specific binding at ≥30,000 pg/mL in 28.4% of samples. Having the apoE4 protein was associated with worse cognitive performance. Higher apoE4 protein levels in those who have it were associated with better cognition. Cardiovascular factors influenced levels of apoE4 protein.