Probing the nanoscale organisation and multivalency of cell surface receptors: DNA origami nanoarrays for cellular studies with single-molecule control.

Nanoscale organisation of receptor ligands has become an important approach to study the clustering behaviour of cell-surface receptors. Biomimetic substrates fabricated via different nanopatterning strategies have so far been applied to investigate specific integrins and cell types, but without multivalent control. Here we use DNA origami to surpass the limits of current approaches and fabricate nanoarrays to study different cell adhesion processes, with nanoscale spatial resolution and single-molecule control. Notably, DNA nanostructures enable the display of receptor ligands in a highly customisable manner, with modifiable parameters including ligand number, ligand spacing and most importantly, multivalency. To test the adaptability and robustness of the system we combined it with focused ion beam and electron-beam lithography nanopatterning to additionally control the distance between the origami structures (i.e. receptor clusters). Moreover, we demonstrate how the platform can be used to interrogate two different biological questions: (1) the cooperative effect of integrin and growth factor receptor in cancer cell spreading, and (2) the role of integrin clustering in cardiomyocyte adhesion and maturation. Thereby we find previously unknown clustering behaviour of different integrins, further outlining the importance for such customisable platforms for future investigations of specific receptor organisation at the nanoscale.

Synchrony of anterior cingulate cortex and insular-striatal activation predicts ambiguity aversion in individuals with low impulsivity.

Personal attitude toward ambiguity contributes to individual differences in decision making in uncertain situations. Operationally, these attitudes reflect the various coping strategies elected to overcome the limited information. A key brain region involved in cognitive control for performance adjustments is the dorsal anterior cingulate cortex (dACC). To test how dACC functional network connectivity would be modulated by uncertainty and differ between individuals, 24 healthy participants underwent functional MRI in 3 sequential runs: 1 resting-state and 2 decision-making task runs. Individuals with lower nonplanning impulsiveness made greater use of a Pass option and avoided uncertain ambiguous situations. Seed-based functional connectivity analysis during the task runs revealed that stronger activation synchrony between the left dACC and the right anterior insula correlated with greater use of a Pass response option. During the resting-state, stronger resting-state functional connectivity between the left dACC and the ventral striatum predicted the adoption of Pass as a behavioral strategy and correlated with stronger task-activated synchrony between the dACC and the right anterior insula. Our findings indicate that that the synchrony between the dACC and insula-striatal circuitry was greater in individuals with low compared with high nonplanning impulsiveness and contributed to adopting Pass as a useful behavioral strategy.

Short-term changes in body composition after surgical repair of hip fracture.

BACKGROUND: the deleterious changes in body composition that occur during the year after hip fracture are associated with increased disability, recurrent fracture, and mortality. While the majority of these unfavourable changes have been shown to occur during the first 2 months after fracture, potential changes in body composition occurring earlier than 2 months post-fracture have not been studied. Accordingly, the aim of this study was to rigorously assess short-term changes in body composition after hip fracture. METHODS: total body mass, lean mass, fat mass and total hip and femoral neck bone mineral density (BMD) were assessed via dual energy X-ray absorptiometry at 3 days, 10 days and 2 months post-fracture among 155 hip fracture patients from the Baltimore Hip Studies. Longitudinal regression analysis using mixed models was conducted to model short-term changes in body composition. RESULTS: no significant changes in body composition were revealed from 3- to 10 days post-fracture. However, significant decreases from 10 days to 2 months post-fracture were noted in the total body mass (-1.95 kg, P < 0.001), lean mass (-1.73 kg, P < 0.001), total hip BMD (-0.00812 g/cm(2), P = 0.04) and femoral neck BMD (-0.015 g/cm(2), P = 0.03). No meaningful changes in fat mass were uncovered. CONCLUSIONS: the adverse changes in body composition during the first 2 months after hip fracture appear to have occurred primarily between 10 days and 2 months post-fracture. More research is needed to determine how these findings might help inform the optimal timing of interventions aimed at improving body composition and related outcomes after hip fracture.

The genome sequence of the Large Sharp-tail Bee, Coelioxys conoideus (Illiger,1806).

We present a genome assembly from an individual female Coelioxys conoideus (the Large Sharp-tail Bee; Arthropoda; Insecta; Hymenoptera; Megachilidae). The genome sequence is 417.6 megabases in span. Most of the assembly is scaffolded into 12 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 20.8 kilobases in length.

The genome sequence of the slender grass hoverfly, Melanostoma scalare (Fabricius, 1794).

We present a genome assembly from an individual male Melanostoma scalare (the slender grass hoverfly; Arthropoda; Insecta; Diptera; Syrphidae). The genome sequence is 738.2 megabases in span. Most of the assembly is scaffolded into 5 chromosomal pseudomolecules, including the X and Y sex chromosomes. The mitochondrial genome has also been assembled and is 16.08 kilobases in length.

The genome sequence of the Common Spotted Hoverfly, Eupeodes luniger (Meigen, 1822).

We present a genome assembly from an individual female Eupeodes luniger (the Common Spotted Hoverfly; Arthropoda; Insecta; Diptera; Syrphidae). The genome sequence is 616.9 megabases in span. Most of the assembly is scaffolded into 4 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 17.45 kilobases in length.

Automated Echocardiographic Detection of Heart Failure With Preserved Ejection Fraction Using Artificial Intelligence.

Background: Detection of heart failure with preserved ejection fraction (HFpEF) involves integration of multiple imaging and clinical features which are often discordant or indeterminate. Objectives: The authors applied artificial intelligence (AI) to analyze a single apical 4-chamber transthoracic echocardiogram video clip to detect HFpEF. Methods: A 3-dimensional convolutional neural network was developed and trained on apical 4-chamber video clips to classify patients with HFpEF (diagnosis of heart failure, ejection fraction ≥50%, and echocardiographic evidence of increased filling pressure; cases) vs without HFpEF (ejection fraction ≥50%, no diagnosis of heart failure, normal filling pressure; controls). Model outputs were classified as HFpEF, no HFpEF, or nondiagnostic (high uncertainty). Performance was assessed in an independent multisite data set and compared to previously validated clinical scores. Results: Training and validation included 2,971 cases and 3,785 controls (validation holdout, 16.8% patients), and demonstrated excellent discrimination (area under receiver-operating characteristic curve: 0.97 [95% CI: 0.96-0.97] and 0.95 [95% CI: 0.93-0.96] in training and validation, respectively). In independent testing (646 cases, 638 controls), 94 (7.3%) were nondiagnostic; sensitivity (87.8%; 95% CI: 84.5%-90.9%) and specificity (81.9%; 95% CI: 78.2%-85.6%) were maintained in clinically relevant subgroups, with high repeatability and reproducibility. Of 701 and 776 indeterminate outputs from the Heart Failure Association-Pretest Assessment, Echocardiographic and Natriuretic Peptide Score, Functional Testing (HFA-PEFF), and Final Etiology and Heavy, Hypertensive, Atrial Fibrillation, Pulmonary Hypertension, Elder, and Filling Pressure (H2FPEF) scores, the AI HFpEF model correctly reclassified 73.5% and 73.6%, respectively. During follow-up (median: 2.3 [IQR: 0.5-5.6] years), 444 (34.6%) patients died; mortality was higher in patients classified as HFpEF by AI (HR: 1.9 [95% CI: 1.5-2.4]). Conclusions: An AI HFpEF model based on a single, routinely acquired echocardiographic video demonstrated excellent discrimination of patients with vs without HFpEF, more often than clinical scores, and identified patients with higher mortality.

The genome sequence of the dumpy grass hoverfly, Melanostoma mellinum (Linnaeus, 1758).

We present a genome assembly from an individual male Melanostoma mellinum (the dumpy grass hoverfly; Arthropoda; Insecta; Diptera; Syriphidae). The genome sequence is 731 megabases in span. The majority of the assembly (99.67%) is scaffolded into five chromosomal pseudomolecules, with the X and Y sex chromosomes assembled. The complete mitochondrial genome was also assembled and is 16.1 kilobases in length.

The genome sequence of the plain-faced dronefly, Eristalis arbustorum (Linnaeus, 1758).

We present a genome assembly from an individual female Eristalis arbustorum (the plain-faced dronefly; Arthropoda; Insecta; Diptera; Syriphidae). The genome sequence is 451 megabases in span. The majority of the assembly (94.71%) is scaffolded into 6 chromosomal pseudomolecules, with the X sex chromosome assembled. The complete mitochondrial genome was also assembled and is 16.0 kilobases in length.

Regulation of cardiomyocyte adhesion and mechanosignalling through distinct nanoscale behaviour of integrin ligands mimicking healthy or fibrotic extracellular matrix.

The stiffness of the cardiovascular environment changes during ageing and in disease and contributes to disease incidence and progression. Changing collagen expression and cross-linking regulate the rigidity of the cardiac extracellular matrix (ECM). Additionally, basal lamina glycoproteins, especially laminin and fibronectin regulate cardiomyocyte adhesion formation, mechanics and mechanosignalling. Laminin is abundant in the healthy heart, but fibronectin is increasingly expressed in the fibrotic heart. ECM receptors are co-regulated with the changing ECM. Owing to differences in integrin dynamics, clustering and downstream adhesion formation this is expected to ultimately influence cardiomyocyte mechanosignalling; however, details remain elusive. Here, we sought to investigate how different cardiomyocyte integrin/ligand combinations affect adhesion formation, traction forces and mechanosignalling, using a combination of uniformly coated surfaces with defined stiffness, polydimethylsiloxane nanopillars, micropatterning and specifically designed bionanoarrays for precise ligand presentation. Thereby we found that the adhesion nanoscale organization, signalling and traction force generation of neonatal rat cardiomyocytes (which express both laminin and fibronectin binding integrins) are strongly dependent on the integrin/ligand combination. Together our data indicate that the presence of fibronectin in combination with the enhanced stiffness in fibrotic areas will strongly impact on the cardiomyocyte behaviour and influence disease progression. This article is part of the theme issue 'The cardiomyocyte: new revelations on the interplay between architecture and function in growth, health, and disease'.

Automated analysis of limited echocardiograms: Feasibility and relationship to outcomes in COVID-19.

Background: As automated echocardiographic analysis is increasingly utilized, continued evaluation within hospital settings is important to further understand its potential value. The importance of cardiac involvement in patients hospitalized with COVID-19 provides an opportunity to evaluate the feasibility and clinical relevance of automated analysis applied to limited echocardiograms. Methods: In this multisite US cohort, the feasibility of automated AI analysis was evaluated on 558 limited echocardiograms in patients hospitalized with COVID-19. Reliability of automated assessment of left ventricular (LV) volumes, ejection fraction (EF), and LV longitudinal strain (LS) was assessed against clinically obtained measures and echocardiographic findings. Automated measures were evaluated against patient outcomes using ROC analysis, survival modeling, and logistic regression for the outcomes of 30-day mortality and in-hospital sequelae. Results: Feasibility of automated analysis for both LVEF and LS was 87.5% (488/558 patients). AI analysis was performed with biplane method in 300 (61.5%) and single plane apical 4- or 2-chamber analysis in 136 (27.9%) and 52 (10.7%) studies, respectively. Clinical LVEF was assessed using visual estimation in 192 (39.3%), biplane in 163 (33.4%), and single plane or linear methods in 104 (21.2%) of the 488 studies; 29 (5.9%) studies did not have clinically reported LVEF. LV LS was clinically reported in 80 (16.4%). Consistency between automated and clinical values demonstrated Pearson's R, root mean square error (RMSE) and intraclass correlation coefficient (ICC) of 0.61, 11.3% and 0.72, respectively, for LVEF; 0.73, 3.9% and 0.74, respectively for LS; 0.76, 24.4ml and 0.87, respectively, for end-diastolic volume; and 0.82, 12.8 ml, and 0.91, respectively, for end-systolic volume. Abnormal automated measures of LVEF and LS were associated with LV wall motion abnormalities, left atrial enlargement, and right ventricular dysfunction. Automated analysis was associated with outcomes, including survival. Conclusion: Automated analysis was highly feasible on limited echocardiograms using abbreviated protocols, consistent with equivalent clinically obtained metrics, and associated with echocardiographic abnormalities and patient outcomes.

Automated Echocardiographic Detection of Severe Coronary Artery Disease Using Artificial Intelligence.

OBJECTIVES: The purpose of this study was to establish whether an artificially intelligent (AI) system can be developed to automate stress echocardiography analysis and support clinician interpretation. BACKGROUND: Coronary artery disease is the leading global cause of mortality and morbidity and stress echocardiography remains one of the most commonly used diagnostic imaging tests. METHODS: An automated image processing pipeline was developed to extract novel geometric and kinematic features from stress echocardiograms collected as part of a large, United Kingdom-based prospective, multicenter, multivendor study. An ensemble machine learning classifier was trained, using the extracted features, to identify patients with severe coronary artery disease on invasive coronary angiography. The model was tested in an independent U.S. STUDY: How availability of an AI classification might impact clinical interpretation of stress echocardiograms was evaluated in a randomized crossover reader study. RESULTS: Acceptable classification accuracy for identification of patients with severe coronary artery disease in the training data set was achieved on cross-fold validation based on 31 unique geometric and kinematic features, with a specificity of 92.7% and a sensitivity of 84.4%. This accuracy was maintained in the independent validation data set. The use of the AI classification tool by clinicians increased inter-reader agreement and confidence as well as sensitivity for detection of disease by 10% to achieve an area under the receiver-operating characteristic curve of 0.93. CONCLUSIONS: Automated analysis of stress echocardiograms is possible using AI and provision of automated classifications to clinicians when reading stress echocardiograms could improve accuracy, inter-reader agreement, and reader confidence.

Left ventricular assessment with artificial intelligence increases the diagnostic accuracy of stress echocardiography.

Aims: To evaluate whether left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS), automatically calculated by artificial intelligence (AI), increases the diagnostic performance of stress echocardiography (SE) for coronary artery disease (CAD) detection. Methods and results: SEs from 512 participants who underwent a clinically indicated SE (with or without contrast) for the evaluation of CAD from seven hospitals in the UK and US were studied. Visual wall motion scoring (WMS) was performed to identify inducible ischaemia. In addition, SE images at rest and stress underwent AI contouring for automated calculation of AI-LVEF and AI-GLS (apical two and four chamber images only) with Ultromics EchoGo Core 1.0. Receiver operator characteristic curves and multivariable risk models were used to assess accuracy for identification of participants subsequently found to have CAD on angiography. Participants with significant CAD were more likely to have abnormal WMS, AI-LVEF, and AI-GLS values at rest and stress (all P < 0.001). The areas under the receiver operating characteristics for WMS index, AI-LVEF, and AI-GLS at peak stress were 0.92, 0.86, and 0.82, respectively, with cut-offs of 1.12, 64%, and -17.2%, respectively. Multivariable analysis demonstrated that addition of peak AI-LVEF or peak AI-GLS to WMS significantly improved model discrimination of CAD [C-statistic (bootstrapping 2.5th, 97.5th percentile)] from 0.78 (0.69-0.87) to 0.83 (0.74-0.91) or 0.84 (0.75-0.92), respectively. Conclusion: AI calculation of LVEF and GLS by contouring of contrast-enhanced and unenhanced SEs at rest and stress is feasible and independently improves the identification of obstructive CAD beyond conventional WMSI.

Frequent manual repositioning and incidence of pressure ulcers among bed-bound elderly hip fracture patients.

Frequent manual repositioning is an established part of pressure ulcer prevention, but there is little evidence for its effectiveness. This study examined the association between repositioning and pressure ulcer incidence among bed-bound elderly hip fracture patients, using data from a 2004-2007 cohort study in nine Maryland and Pennsylvania hospitals. Eligible patients (n=269) were age ≥ 65 years, underwent hip fracture surgery, and were bed-bound at index study visits (during the first 5 days of hospitalization). Information about repositioning on the days of index visits was collected from patient charts; study nurses assessed presence of stage 2+ pressure ulcers 2 days later. The association between frequent manual repositioning and pressure ulcer incidence was estimated, adjusting for pressure ulcer risk factors using generalized estimating equations and weighted estimating equations. Patients were frequently repositioned (at least every 2 hours) on only 53% (187/354) of index visit days. New pressure ulcers developed at 12% of visits following frequent repositioning vs. 10% following less frequent repositioning; the incidence rate of pressure ulcers per person-day did not differ between the two groups (incidence rate ratio 1.1, 95% confidence interval 0.5-2.4). No association was found between frequent repositioning of bed-bound patients and lower pressure ulcer incidence, calling into question the allocation of resources for repositioning.

Physical activity in the post-hip-fracture period.

The purpose of this study was to characterize physical activity (PA) based on survey and ActiGraphy data from older adults at 2 mo post-hip fracture and consider the factors that influence PA among these individuals. The sample included participants from a current Baltimore hip study, the BHS-7. Measurement of PA was based on the Yale PA Survey (YPAS) and 48 hr of ActiGraphy. The sample included the first 200 individuals enrolled in the study, with analyses including 117 individuals (59%) who completed the YPAS and wore the ActiGraph for 48 hr. Half the participants were male, with an overall mean age of 81.3 yr (SD = 7.9). Findings indicate that at 2 mo post-hip fracture participants were engaged in very limited levels of PA. Age and comorbidities were the only variables to be significantly associated with PA outcomes.

The genome sequence of the tapered dronefly, Eristalis pertinax (Scopoli, 1763).

We present a genome assembly from an individual male Eristalis tenax (the tapered dronefly; Arthropoda; Insecta; Diptera; Syriphidae). The genome sequence is 487 megabases in span. The majority of the assembly (95.23%) is scaffolded into seven chromosomal pseudomolecules, with the X and Y sex chromosomes assembled. The complete mitochondrial genome was also assembled and is 17.2 kilobases in length.

The genome sequence of the two-banded wasp hoverfly, Chrysotoxum bicinctum (Linnaeus, 1758).

We present a genome assembly from an individual female Chrysotoxum bicinctum (the two-banded wasp hoverfly; Arthropoda; Insecta; Diptera; Syriphidae). The genome sequence is 913 megabases in span. The majority of the assembly (98.81%) is scaffolded into five chromosomal pseudomolecules, with the X sex chromosome assembled.

Repeat falls and the recovery of social participation in the year post-hip fracture.

BACKGROUND: although the majority of hip fractures are the result of a fall, whether repeated falls in the year post-fracture adversely influence recovery of social participation is not known. DESIGN: analysis of data from a longitudinal cohort study. SUBJECTS: community-dwelling women aged > or = 65 years, admitted to one of two hospitals in Baltimore with a new, non-pathological fracture of the proximal femur between 1992 and 1995. METHODS: information on falls was collected from a falls diary. At the baseline, 6- and 12-month evaluations, subjects were asked about the number of times in the 2 weeks prior to the evaluation they had participated in 10 categories of social activities. We examined the association of repeated falls with social participation using generalized estimating equations. The effect of physical and psychological functions was examined by including measures of lower extremity functional performance and depressive symptoms into the model. RESULTS: the analyses included 196 women, mean age = 80.2 years. Eighty-one subjects fell. The subjects with >1 fall between evaluations participated in a mean (95% CI) of 3.5 (0.12, 6.9) and 4.3 (0.9, 7.7) fewer social activities at 6 and 12 months post-fracture, respectively, compared to those who did not fall (P = 0.0003). These results were attenuated by adjustment for depressive symptoms, but not by lower extremity functional performance. CONCLUSIONS: in the year post-fracture, repeated falls in women were associated with decreased social participation independent of lower extremity function. Depressive symptoms in repeated fallers may partly explain this association.

The association of race, gender, and comorbidity with mortality and function after hip fracture.

BACKGROUND: Few studies of hip fracture have large enough samples of men, minorities, and persons with specific comorbidities to examine differences in their mortality and functional outcomes. To address this problem, we combined three cohorts of hip fracture patients to produce a sample of 2692 patients followed for 6 months. METHOD: Data on mortality, mobility, and other activities of daily living (ADLs) were available from all three cohorts. We used multiple regression to examine the association of race, gender, and comorbidity with 6-month survival and function, controlling for prefracture mobility and ADLs, age, fracture type, cohort, and admission year. RESULTS: The mortality rate at 6 months was 12%: 9% for women and 19% for men. Whites and women were more likely than were nonwhites and men to survive to 6 months, after adjusting for age, comorbidities, and prefracture mobility and function. Whites were more likely than were nonwhites to walk independently or with help at 6 months compared to not walking, after adjusting for age, comorbidities, and prefracture mobility and function. Dementia had a negative impact on survival, mobility, and ADLs at 6 months. The odds of survival to 6 months were significantly lower for people with chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), and/or cancer. Parkinson's disease and stroke had negative impacts on mobility and ADLs, respectively, among survivors at 6 months. CONCLUSIONS: The finding of higher mortality and worse mobility for nonwhite patients with hip fractures highlights the need for more research on race/ethnicity disparities in hip fracture care.