Search

Abstract Objective Myasthenia gravis (MG) is an autoantibody‐mediated neuromuscular junction disorder involving the acetylcholine receptors on the motor endplate. The safety and response to high‐dose chemotherapy (HDIT) and autologous hematopoietic cell transplantation (HCT) were assessed in a patient with severe refractory MG. Methods As part of a pilot study of HDIT/HCT for patients with treatment‐resistant autoimmune neurological disorders, a patient with severe refractory MG underwent treatment. After mobilization of hematopoietic stem cells with rituximab, prednisone, and G‐CSF, the patient had HDIT consisting of carmustine, etoposide, cytarabine, melphalan, and rabbit antithymocyte globulin, followed by autologous HCT. The effect of treatment on the autoantibody to the acetylcholine receptor (AChR) was assessed. Results The patient had been diagnosed with AChR antibody‐positive MG 14 years before HDIT/HCT and had failed thymectomy, therapeutic plasma exchange, and multiple immunomodulatory agents. The Myasthenia Gravis Foundation of America (MGFA) clinical classification was IVb before HDIT/HCT. She tolerated HDIT/HCT well and started to improve clinically within days of treatment. At both 1 and 2 years after HDIT/HCT, patients remained symptom‐free. After HDIT/HCT, AChR‐binding autoantibodies persisted, and the relative frequency of immune cell subtypes shifted. Interpretation HDIT/HCT induced a complete response of disease activity in a patient with severe refractory MG. This response may suggest that a cell‐mediated etiology may be a significant contributing factor in refractory MG cases. A phase 2 clinical trial is warranted to establish if HDIT/HCT can be an effective therapy for severe refractory MG and to gain a further understanding of disease pathogenesis.

Abstract Aims The Candesartan in Heart failure Assessment of Reduction in Mortality and morbidity (CHARM) programme consisted of three parallel, randomized, double‐blind clinical trials comparing candesartan with placebo in patients with heart failure (HF) categorized according to left ventricular ejection fraction and tolerability to an angiotensin‐converting enzyme inhibitor. We conducted a pharmacogenomic study of the CHARM trials with the objective of identifying genetic predictors of HF progression and of the efficacy and safety of treatment with candesartan. Methods We performed genome‐wide association studies in 2727 patients of European ancestry from CHARM‐Overall and stratified by CHARM study according to preserved and reduced ejection fraction and according to assignment to the interventional treatment with candesartan. We tested genetic association with the composite endpoint of cardiovascular death or hospitalization for heart failure for drug efficacy in candesartan‐treated patients and for HF progression using patients from both candesartan and placebo arms. The safety endpoints for response to candesartan were hyperkalaemia, renal dysfunction, hypotension, and change in systolic blood pressure between baseline and 6 weeks of treatment. To support our observations, we conducted a genome‐wide gene‐level collapsing analysis from whole‐exome sequencing data with the composite cardiovascular endpoint. Results We found that the A allele (14% allele frequency) of the genetic variant rs66886237 at 8p21.3 near the gene GFRA2 was associated with the composite cardiovascular endpoint in 1029 HF patients with preserved ejection fraction from the CHARM‐Preserved study (hazard ratio: 1.91, 95% confidence interval: 1.55–2.35; P = 1.7 × 10−9). The association was independent of candesartan treatment, and the genetic variant was not associated with the cardiovascular endpoint in patients with reduced ejection fraction. None of the genome‐wide association studies for candesartan safety or efficacy conducted in patients treated with candesartan passed the significance threshold. We found no significant association from the gene‐level collapsing analysis. Conclusions We have identified a candidate genetic variant potentially predictive of the progression of heart failure in patients with preserved ejection fraction. The findings require further replication, and we cannot exclude the possibility that the results may be chance findings.

Abstract Differences in ecosystem service (ES) priorities often lead to conflicts between stakeholders. While differences in priorities have often been described, the sociocultural factors, including differences in cultural worldview, which drive them have not. We propose that the cultural theory of risk and its ‘grid‐group’ typology, which classifies people as individualists, hierarchists, egalitarians and fatalists, can provide a conceptual framework for doing this. We examined the relationship between ES prioritisation by stakeholders and underlying cultural (cultural worldviews, and related environmental nature and risk perceptions), sociocultural (region, stakeholder group, political party preference) and socio‐demographic factors. This was achieved by applying multivariate statistics to data from a survey with 321 respondents, conducted across 14 stakeholder groups in three German regions. Results show that most stakeholders prioritised many services but gave the highest priority to services linked to their stakeholder group. We identified four ‘ES priority bundles’: cultural services, open‐land provisioning services, environmental protection services and forest provisioning services. Each ES priority bundle was consistently associated with particular cultural worldviews, perceptions of nature and sociocultural factors, meaning that we could identify ‘cultural types’. Two of these associations were particularly strong: Prioritisation of open‐land provisioning ES was high for the agriculture stakeholder group, associated with individualism, a perception of nature as durable but unpredictable, and support for economic liberal, conservative political parties. In contrast, those who prioritised environmental protection tended to hold egalitarian cultural worldviews and perceive nature as tolerant and sensitive. They also often belonged to the research and nature conservation stakeholder groups, with a mostly left‐leaning political party preference. The identification of cultural types of stakeholder with consistent ES priorities and cultural worldviews may provide a useful construct in the future ES research. Furthermore, it may allow communications regarding ES to be tailored to improve their effectiveness, potentially aiding the promotion of sustainable management strategies. A free Plain Language Summary can be found within the Supporting Information of this article.

Abstract Bat communities in the Neotropics are some of the most speciose assemblages of mammals on Earth, with regions supporting more than 100 sympatric species with diverse feeding ecologies. Because bats are small, nocturnal, and volant, it is difficult to directly observe their feeding habits, which has resulted in their classification into broadly defined dietary guilds (e.g., insectivores, carnivores, and frugivores). Apart from these broad guilds, we lack detailed dietary information for many species and therefore have only a limited understanding of interaction networks linking bats and their diet items. In this study, we used DNA metabarcoding of plants, arthropods, and vertebrates to investigate the diets of 25 bat species from the tropical dry forests of Lamanai, Belize. Our results report some of the first detection of diet items for the focal bat taxa, adding rich and novel natural history information to the field of bat ecology. This study represents a comprehensive first effort to apply DNA metabarcoding to bat diets at Lamanai and provides a useful methodological framework for future studies testing hypotheses about coexistence and niche differentiation in the context of modern high‐throughput molecular data.

Abstract Aims Few investigations have been conducted to identify genetic determinants of common, polygenetic forms of heart failure (HF), and only a limited number of these genetic associations have been validated by multiple groups. Methods and results We performed a case–control study to further investigate the potential impact of 14 previously reported candidate genes on the risk of HF and specific HF sub‐types. We also performed an exploratory genome‐wide study. We included 799 patients with HF and 1529 controls. After adjusting for age, sex, and genetic ancestry, we found that the C allele of rs2234962 in BAG3 was associated with a decreased risk of idiopathic dilated cardiomyopathy (odds ratio 0.42, 95% confidence interval 0.25–0.68, P = 0.0005), consistent with a previous report. No association for the other primary variants or exploratory genome‐wide study was found. Conclusions Our findings provide independent replication for the association between a common coding variant (rs2234962) in BAG3 and the risk of idiopathic dilated cardiomyopathy.

Abstract A striking feature of the human pulmonary circulation is that mean (mPAP) and systolic (sPAP) pulmonary artery pressures (PAPs) are strongly related and, thus, are essentially redundant. According to the empirical formula documented under normotensive and hypertensive conditions (mPAP = 0.61 sPAP + 2 mmHg), sPAP matches ~160%mPAP on average. This attests to the high pulsatility of PAP, as also witnessed by the near equality of PA pulse pressure and mPAP. Our prospective study tested if pressure redundancy and high pulsatility also apply in a piglet model of chronic thromboembolic pulmonary hypertension (CTEPH). At baseline (Week‐0, W0), Sham (n = 8) and CTEPH (n = 27) had similar mPAP and stroke volume. At W6, mPAP increased in CTEPH only, with a two‐ to three‐fold increase in PA stiffness and total pulmonary resistance. Seven CTEPH piglets were also studied at W16 at baseline, after volume loading, and after acute pulmonary embolism associated with dobutamine infusion. There was a strong linear relationship between sPAP and mPAP (1) at W0 and W6 (n = 70 data points, r² = 0.95); (2) in the subgroup studied at W16 (n = 21, r² = 0.97); and (3) when all data were pooled (n = 91, r² = 0.97, sPAP range 9–112 mmHg). The PA pulsatility was lower than that expected based on observations in humans: sPAP matched ~120%mPAP only and PA pulse pressure was markedly lower than mPAP. In conclusion, the redundancy between mPAP and sPAP seems a characteristic of the pulmonary circulation independent of the species. However, it is suggested that the sPAP thresholds used to define PH in animals are species‐ and/or model‐dependent and thus must be validated.

Abstract Background The vision of learning healthcare systems (LHSs) is attractive as a more effective model for health care services, but achieving the vision is complex. There is limited literature describing the processes needed to construct such multicomponent systems or to assess development. Methods We used the concept of a capability maturity matrix to describe the maturation of necessary infrastructure and processes to create learning networks (LNs), multisite collaborative LHSs that use an actor‐oriented network organizational architecture. We developed a network maturity grid (NMG) assessment tool by incorporating information from literature review, content theory from existing networks, and expert opinion to establish domains and components. We refined the maturity grid in response to feedback from network leadership teams. We followed NMG scores over time for nine LNs and plotted scores for each domain component with respect to SD for one participating network. We sought subjective feedback on the experience of applying the NMG to individual networks. Results LN leaders evaluated the scope, depth, and applicability of the NMG to their networks. Qualitative feedback from network leaders indicated that changes in NMG scores over time aligned with leaders' reports about growth in specific domains; changes in scores were consistent with network efforts to improve in various areas. Scores over time showed differences in maturation in the individual domains of each network. Scoring patterns, and SD for domain component scores, indicated consistency among LN leaders in some but not all aspects of network maturity. A case example from a participating network highlighted the value of the NMG in prompting strategic discussions about network development and demonstrated that the process of using the tool was itself valuable. Conclusions The capability maturity grid proposed here provides a framework to help those interested in creating Learning Health Networks plan and develop them over time.

Abstract Introduction Amyloid‐related imaging abnormalities (ARIA) are a common, dose‐dependent effect of amyloid‐targeting antibodies, strongly associated with the apolipoprotein E (APOE) ε4 allele. Methods We describe the clinical course and management of a 66‐year‐old white male (APOE ε4/ε4) enrolled in an observational study that included amyloid and tau positron emission tomography (PET), who received aducanumab through the ENGAGE clinical trial. Results Acute symptoms included headache and encephalopathy, and magnetic resonance imaging revealed ARIA‐E and ARIA‐H. Malignant hypertension and epileptiform activity were treated with nicardipine and levetiracetam. Subsequent clinical/imaging worsening prompted a course of methylprednisolone. Symptoms and ARIA‐E resolved over 6 months, while ARIA‐H persisted. Quantitative analysis of interval amyloid PET showed reduced signal in pre‐existing areas but increased signal posteriorly; while tau PET showed increased signal overall. Discussion In an APOE ε4/ε4 patient, ARIA symptoms were accompanied by malignant hypertension and epileptiform activity, and pulsed steroids reversed edema. Studies from larger cohorts may clarify the optimal treatment and pathophysiology of ARIA.

Pulmonary arterial hypertension (PAH) is an incurable disease characterized by an increase in pulmonary arterial pressure due to pathological changes to the pulmonary vascular bed. As a result, the right ventricle (RV) is subject to an increased afterload and undergoes multiple changes, including a decrease in capillary density. All of these dysfunctions lead to RV failure. A number of studies have shown that RV function is one of the main prognostic factors for PAH patients. Many stem cell therapies targeting the left ventricle are currently undergoing development. The promising results observed in animal models have led to clinical trials that have shown an improvement of cardiac function. In contrast to left heart disease, stem cell therapy applied to the RV has remained poorly studied, even though it too may provide a therapeutic benefit. In this review, we discuss stem cell therapy as a treatment for RV failure in PAH. We provide an overview of the results of preclinical and clinical studies for RV cell therapies. Although a large number of studies have targeted the pulmonary circulation rather than the RV directly, there are nonetheless encouraging results in the literature that indicate that cell therapies may have a direct beneficial effect on RV function. This cell therapy strategy may therefore hold great promise and warrants further studies in PAH patients.

MicroRNAs are small gene-regulatory RNAs that are found in various biological fluids, including milk, where they are often contained inside extracellular vesicles (EVs), like exosomes. In a previous study, we reported that commercial dairy cow’s milk microRNAs resisted simulated digestion and were not exclusively associated with canonical exosomes. Here, we report the characterization of a milk EV subset that sediments at lower ultracentrifugation speeds and that contains the bulk of microRNAs. Milk EVs were isolated by differential ultracentrifugation and Iodixanol density gradient (IDG), and analysed for (1) microRNA enrichment by reverse transcription and quantitative polymerase chain reaction (RT-qPCR), and (2) EV-associated proteins by Western blot. Milk EVs were characterized further by dynamic light scattering (DLS), density measurements, fluorescent DiR and RNA labelling, high-sensitivity flow cytometry (HS-FCM), transmission electron microscopy (TEM), proteinase K and RNase A assay, and liquid chromatography tandem-mass spectrometry (LC-MS/MS). We found that the bulk of milk microRNAs (e.g., bta-miR-125b, bta-miR-148a, etc.) sediment at 12,000 g and 35,000 g. Their distribution pattern was different from that of exosome-enriched proteins, but similar to that of several proteins commonly found in milk fat globule membranes (MFGM), including xanthine dehydrogenase (XDH). These low-speed ultracentrifugation pellets contained cytoplasm-enclosing phospholipid bilayered membrane vesicles of a density comprised between 1.11 and 1.14 g/mL in Iodixanol. This milk EV subset of ~100 nm in diameter/~200 nm hydrodynamic size resisted to proteinase K digestion and protected their microRNA content from RNase A digestion. Our results support the existence of a milk EV subset pelleting at low ultracentrifugations speeds, with a protein coating comparable with MFGM, which contains and protects the bulk of milk microRNAs from degradation. This milk EV subset may represent a new EV population of interest, whose content in microRNAs and proteins supports its potential bioactivity.