Now showing items 21-40 of 1903

    • Gene editing enables rapid engineering of complex antibiotic assembly lines

      Thong, Wei Li; Zhang, Yingxin; Zhuo, Ying; Robins, Katherine J.; orcid: 0000-0001-5049-4246; Fyans, Joanna K.; Herbert, Abigail J.; Law, Brian J. C.; Micklefield, Jason; orcid: 0000-0001-8951-4873; email: jason.micklefield@manchester.ac.uk (Nature Publishing Group UK, 2021-11-25)
      Abstract: Re-engineering biosynthetic assembly lines, including nonribosomal peptide synthetases (NRPS) and related megasynthase enzymes, is a powerful route to new antibiotics and other bioactive natural products that are too complex for chemical synthesis. However, engineering megasynthases is very challenging using current methods. Here, we describe how CRISPR-Cas9 gene editing can be exploited to rapidly engineer one of the most complex megasynthase assembly lines in nature, the 2.0 MDa NRPS enzymes that deliver the lipopeptide antibiotic enduracidin. Gene editing was used to exchange subdomains within the NRPS, altering substrate selectivity, leading to ten new lipopeptide variants in good yields. In contrast, attempts to engineer the same NRPS using a conventional homologous recombination-mediated gene knockout and complementation approach resulted in only traces of new enduracidin variants. In addition to exchanging subdomains within the enduracidin NRPS, subdomains from a range of NRPS enzymes of diverse bacterial origins were also successfully utilized.
    • Resurgence of a Nation’s Radiation Science Driven by Its Nuclear Industry Needs

      Leay, Laura; email: laura.leay@outlook.com; Baidak, Aliaksandr; email: aliaksandr.baidak@manchester.ac.uk; Anderson, Christopher; orcid: 0000-0003-4452-4378; email: christopher.anderson-3@postgrad.manchester.ac.uk; Chan, Choen May; email: ChoenMay.Chan@jacobs.com; Daubney, Aaron; email: aaron.daubney@sellafieldsites.com; Donoclift, Thomas; email: Thomas.Donoclift@glasgow.ac.uk; Draper, Gemma; email: gemma.draper@stfc.ac.uk; Edge, Ruth; orcid: 0000-0002-9144-041X; email: ruth.edge@manchester.ac.uk; Hobbs, Jeff; email: jeff.w.hobbs@sellafieldsites.com; Jones, Luke; email: Luke.Jones@uknnl.com; et al. (MDPI, 2021-11-23)
      This article describes the radiation facilities and associated sample preparation, management, and analysis equipment currently in place at the Dalton Cumbrian Facility, a facility which opened in 2011 to support the UK’s nuclear industry. Examples of measurements performed using these facilities are presented to illustrate their versatility and the breadth of research they make possible. Results are presented from research which furthers our understanding of radiation damage to polymeric materials, radiolytic yield of gaseous products in situations relevant to nuclear materials, radiation chemistry in light water reactor cooling systems, material chemistry relevant to immobilization of nuclear waste, and radiation-induced corrosion of fuel cladding elements. Applications of radiation chemistry relevant to health care are also described. Research concerning the mechanisms of radioprotection by dietary carotenoids is reported. An ongoing open-labware project to develop a suite of modular sample handling components suited to radiation research is described, as is the development of a new neutron source able to provide directional beams of neutrons.
    • Broadband measurement of true transverse relaxation rates in systems with coupled protons: application to the study of conformational exchange.

      Kiraly, Peter; orcid: 0000-0003-3540-4876; Dal Poggetto, Guilherme; orcid: 0000-0003-0591-9166; Castañar, Laura; orcid: 0000-0002-4731-0626; Nilsson, Mathias; orcid: 0000-0003-3301-7899; Deák, Andrea; orcid: 0000-0001-7988-0255; Morris, Gareth A; orcid: 0000-0002-4859-6259 (2021-08-03)
      Accurate measurement of transverse relaxation rates in coupled spin systems is important in the study of molecular dynamics, but is severely complicated by the signal modulations caused by scalar couplings in spin echo experiments. The most widely used experiments for measuring transverse relaxation in coupled systems, CPMG and PROJECT, can suppress such modulations, but they also both suppress some relaxation contributions, and average relaxation rates between coupled spins. Here we introduce a new experiment which for the first time allows accurate broadband measurement of transverse relaxation rates of coupled protons, and hence the determination of exchange rate constants in slow exchange from relaxation measurements. The problems encountered with existing methods are illustrated, and the use of the new method is demonstrated for the classic case of hindered amide rotation and for the more challenging problem of exchange between helical enantiomers of a gold(i) complex.
    • Combined bezafibrate, medroxyprogesterone acetate and valproic acid treatment inhibits osteosarcoma cell growth without adversely affecting normal mesenchymal stem cells

      Sheard, Jonathan J.; Southam, Andrew D.; MacKay, Hannah L.; Ellington, Max A.; Snow, Martyn D.; Khanim, Farhat L.; Bunce, Christopher M.; Johnson, William E.; orcid: 0000-0002-7247-9087 (Portland Press Ltd., 2021-01-05)
      Abstract Drug repurposing is a cost-effective means of targeting new therapies for cancer. We have examined the effects of the repurposed drugs, bezafibrate, medroxyprogesterone acetate and valproic acid on human osteosarcoma cells, i.e., SAOS2 and MG63 compared with their normal cell counterparts, i.e. mesenchymal stem/stromal cells (MSCs). Cell growth, viability and migration were measured by biochemical assay and live cell imaging, whilst levels of lipid-synthesising enzymes were measured by immunoblotting cell extracts. These drug treatments inhibited the growth and survival of SAOS2 and MG63 cells most effectively when used in combination (termed V-BAP). In contrast, V-BAP treated MSCs remained viable with only moderately reduced cell proliferation. V-BAP treatment also inhibited migratory cell phenotypes. MG63 and SAOS2 cells expressed much greater levels of fatty acid synthase and stearoyl CoA desaturase 1 than MSCs, but these elevated enzyme levels significantly decreased in the V-BAP treated osteosarcoma cells prior to cell death. Hence, we have identified a repurposed drug combination that selectively inhibits the growth and survival of human osteosarcoma cells in association with altered lipid metabolism without adversely affecting their non-transformed cell counterparts.
    • Suicide rates by ethnic group among patients in contact with mental health services: an observational cohort study in England and Wales.

      Hunt, Isabelle M; email: isabelle.m.hunt@manchester.ac.uk; Richards, Nicola; Bhui, Kamaldeep; Ibrahim, Saied; Turnbull, Pauline; Halvorsrud, Kristoffer; Saini, Pooja; Kitson, Sadie; Shaw, Jenny; Appleby, Louis; et al. (2021-11-08)
      Recent evidence on suicide rates among psychiatric patients from minority ethnic backgrounds is scarce. We aimed to examine suicide rates among minority ethnic psychiatric patients and describe their social and clinical characteristics. We did a retrospective observational cohort study on a national case-series of patients in England and Wales who died by suicide within 12 months of contact with mental health services between 2007 and 2018. Data were collected as part of the National Confidential Inquiry into Suicide and Safety in Mental Health. Suicide rates and standardised mortality ratios (SMRs) were estimated for South Asian (Indian, Pakistani, and Bangladeshi), Black African, Black Caribbean, Chinese, and White patients. A total of 698 patients in the four minority ethnic groups of South Asian, Black Caribbean, Black African, and Chinese were included (482 [69%] men; 216 [31%] women; mean age 41 years [SD 14·9, range 12-91] and compared with 13 567 White patients (9030 [66·6%] men; 4537 [33·4%] women; mean age 48 years [SD 15·8, range 10-100]). Rates and SMRs for suicide among minority ethnic patients were lower than for White patients (2·73 deaths, 95% CI 2·68-2·78) per 100 000 population. Differences were found between ethnic groups with higher suicide rates in Black Caribbean patients (1·89 deaths [95% CI 1·55-2·23] per 100 000 population) and lower rates in South Asian patients (1·49 deaths [1·33-1·64] per 100 000 population). There was an increase in rates among White patients in 2007-12 followed by a fall but no change among other ethnic groups. Schizophrenia was more common among Black African patients (54%) and Black Caribbean patients (44%), while affective disorder was more common among South Asian patients (41%). Minority ethnic patients overall showed markers of social adversity and received higher intensity care yet were viewed by clinicians as at lower risk than White patients. Effective approaches to prevention might differ between minority ethnic groups. Clinicians and the services in which they work should be aware of the common and distinct social and clinical needs of minority ethnic patients with mental illness. The Healthcare Quality Improvement Partnership. [Abstract copyright: Copyright © 2021 Elsevier Ltd. All rights reserved.]
    • Electrochemically detecting DNA methylation in the EN1 gene promoter: implications for understanding ageing and disease

      Morgan, Amy E.; Acutt, Katie D.; Mc Auley, Mark T.; orcid: 0000-0001-9230-6928 (Portland Press Ltd., 2020-11-17)
      Abstract There is a growing need for biomarkers which predict age-onset pathology. Although this is challenging, the methylome offers significant potential. Cancer is associated with the hypermethylation of many gene promoters, among which are developmental genes. Evolutionary theory suggests developmental genes arbitrate early-late life trade-offs, causing epimutations that increase disease vulnerability. Such genes could predict age-related disease. The aim of this work was to optimise an electrochemical procedure for the future investigation of a broad range of ageing-related pathologies. An electrochemical approach, which adopted three analytical techniques, was used to investigate DNA methylation in the engrailed-1 (EN1) gene promoter. Using synthetic single-stranded DNA, one technique was able to detect DNA at concentrations as low as 10 nM, with methylation status distinguishable at concentrations >25 nM. A negative correlation could be observed between % methylation of a heterogeneous solution and the key electrochemical parameter, charge transfer resistance (Rct; r = −0.982, P<0.01). The technique was applied to the breast cancer cell line Michigan Cancer Foundation-7 (MCF-7), where a similar correlation was observed (r = −0.965, P<0.01). These results suggest electrochemistry can effectively measure DNA methylation at low concentrations of DNA. This has implications for the future detection of age-related disease.
    • The supervisor conundrum.

      Knight, Kate H; Leigh, Jacqueline; Whaley, Victoria; Rabie, Gay; Matthews, Marie; Doyle, Kate (2021-11-11)
    • Behavioural Indicators of Intra- and Inter-Specific Competition: Sheep Co-Grazing with Guanaco in the Patagonian Steppe

      Fernández, Tomás; email: tomas.fv@gmail.com; Lancaster, Alex; email: 1821496@chester.ac.uk; Moraga, Claudio A.; email: clmoraga@gmail.com; Radic-Schilling, Sergio; email: sergio.radic@umag.cl; von Hardenberg, Achaz; email: a.vonhardenberg@chester.ac.uk; Corti, Paulo; orcid: 0000-0002-8253-2195; email: pcorti@uach.cl (MDPI, 2021-11-22)
      In extensive livestock production, high densities may inhibit regulation processes, maintaining high levels of intraspecific competition over time. During competition, individuals typically modify their behaviours, particularly feeding and bite rates, which can therefore be used as indicators of competition. Over eight consecutive seasons, we investigated if variation in herd density, food availability, and the presence of a potential competitor, the guanaco (Lama guanicoe), was related with behavioural changes in domestic sheep in Chilean Patagonia. Focal sampling, instantaneous scan sampling, measures of bite and movement rates were used to quantify behavioural changes in domestic sheep. We found that food availability increased time spent feeding, while herd density was associated with an increase in vigilant behaviour and a decrease in bite rate, but only when food availability was low. Guanaco presence appeared to have no impact on sheep behaviour. Our results suggest that the observed behavioural changes in domestic sheep are more likely due to intraspecific competition rather than interspecific competition. Consideration of intraspecific competition where guanaco and sheep co-graze on pastures could allow management strategies to focus on herd density, according to rangeland carrying capacity.
    • First observation of radiolytic bubble formation in unstirred nano-powder sludges and a consistent model thereof

      O’Leary, Mel; email: mel.oleary@manchester.ac.uk; Baidak, Aliaksandr; Barnes, Martyn; Donoclift, Thomas; Emerson, Christopher; Figueira, Catarina; Fox, Oliver; Kleppe, Annette; McCulloch, Aaron; Messer, Darryl; et al. (Nature Publishing Group UK, 2021-11-24)
      Abstract: Experiments involving the irradiation of water contained within magnesium hydroxide and alumina nanoparticle sludges were conducted and culminated in observations of an increased yield of molecular hydrogen when compared to the yield from the irradiation of bulk water. We show that there is a relationship linking this increased yield to the direct nanoscale ionization mechanism in the nanoparticles, indicating that electron emission from the nanoparticles drives new radiative pathways in the water. Because the chemical changes in these sludges are introduced by irradiation only, we have a genuinely unstirred system. This feature allows us to determine the diffusivity of the dissolved gas. Using the measured gas production rate, we have developed a method for modelling when hydrogen bubble formation will occur within the nanoparticle sludges. This model facilitates the determination of a consistent radiolytic consumption rate coinciding with the observations of bubble formation. Thus, we demonstrate a nanoscale radiation effect directly influencing the formation of molecular hydrogen.
    • TIAM1-RAC1 promote small-cell lung cancer cell survival through antagonizing Nur77-induced BCL2 conformational change.

      Payapilly, Aishwarya; Guilbert, Ryan; Descamps, Tine; White, Gavin; Magee, Peter; Zhou, Cong; Kerr, Alastair; Simpson, Kathryn L; Blackhall, Fiona; Dive, Caroline; et al. (2021-11-09)
      Small-cell lung cancer (SCLC), an aggressive neuroendocrine malignancy, has limited treatment options beyond platinum-based chemotherapy, whereafter acquired resistance is rapid and common. By analyzing expression data from SCLC tumors, patient-derived models, and established cell lines, we show that the expression of TIAM1, an activator of the small GTPase RAC1, is associated with a neuroendocrine gene program. TIAM1 depletion or RAC1 inhibition reduces viability and tumorigenicity of SCLC cells by increasing apoptosis associated with conversion of BCL2 from its pro-survival to pro-apoptotic function via BH3 domain exposure. This conversion is dependent upon cytoplasmic translocation of Nur77, an orphan nuclear receptor. TIAM1 interacts with and sequesters Nur77 in SCLC cell nuclei and TIAM1 depletion or RAC1 inhibition promotes Nur77 translocation to the cytoplasm. Mutant TIAM1 with reduced Nur77 binding fails to suppress apoptosis triggered by TIAM1 depletion. In conclusion, TIAM1-RAC1 signaling promotes SCLC cell survival via Nur77 nuclear sequestration. [Abstract copyright: Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.]
    • Can Skin Aging Contribute to Systemic Inflammaging?

      Pilkington, Suzanne M; email: suzanne.pilkington@manchester.ac.uk; Bulfone-Paus, Silvia; Griffiths, Christopher E M; Watson, Rachel E B (2021-10-28)
    • Gut thinking and eye tracking: evidence for a central preference heuristic

      Thoma, Volker; Rodway, Paul; orcid: 0000-0002-7667-6782; Tamlyn, Guy (Informa UK Limited, 2021-09-01)
    • Oxygen Depletion in Proton Spot Scanning: A Tool for Exploring the Conditions Needed for FLASH

      Rothwell, Bethany C.; orcid: 0000-0002-3323-671X; email: bethany.rothwell@postgrad.manchester.ac.uk; Lowe, Matthew; orcid: 0000-0002-7685-8156; email: matthew.lowe11@nhs.net; Kirkby, Norman F.; orcid: 0000-0001-5352-8069; email: norman.kirkby@manchester.ac.uk; Merchant, Michael J.; orcid: 0000-0001-8422-5255; email: michael.merchant@manchester.ac.uk; Chadwick, Amy L.; orcid: 0000-0002-7841-0507; email: amy.chadwick@manchester.ac.uk; Mackay, Ranald I.; orcid: 0000-0002-7329-6127; email: ranald.mackay@nhs.net; Hendry, Jolyon H.; email: jolyon.hendry@manchester.ac.uk; Kirkby, Karen J.; orcid: 0000-0002-0901-210X; email: karen.kirkby@manchester.ac.uk (MDPI, 2021-11-22)
      FLASH radiotherapy is a rapidly developing field which promises improved normal tissue protection compared to conventional irradiation and no compromise on tumour control. The transient hypoxic state induced by the depletion of oxygen at high dose rates provides one possible explanation. However, studies have mostly focused on uniform fields of dose and there is a lack of investigation into the spatial and temporal variation of dose from proton pencil-beam scanning (PBS). A model of oxygen reaction and diffusion in tissue has been extended to simulate proton PBS delivery and its impact on oxygen levels. This provides a tool to predict oxygen effects from various PBS treatments, and explore potential delivery strategies. Here we present a number of case applications to demonstrate the use of this tool for FLASH-related investigations. We show that levels of oxygen depletion could vary significantly across a large parameter space for PBS treatments, and highlight the need for in silico models such as this to aid in the development and optimisation of FLASH radiotherapy.
    • Overview of epidemiological studies of nuclear workers: opportunities, expectations, and limitations ∗ ∗ Based upon an invited presentation in Special Session 9 of the IRPA15 Virtual Congress, January–February 2021.

      Wakeford, Richard; orcid: 0000-0002-2934-0987; email: Richard.Wakeford@manchester.ac.uk (IOP Publishing, 2021-11-11)
      Abstract: Epidemiological studies of those exposed occupationally to ionising radiation offer an important opportunity to directly check the assumptions underlying the international system of radiological protection against low-level radiation exposures. Recent nuclear worker studies, notably the International Nuclear Workers Study (INWORKS) and studies of the Mayak workforce in Russia, provide powerful investigations of a wide range of cumulative photon doses received at a low dose-rate over protracted periods, and broadly confirm radiation-related excess risks of leukaemia and solid cancers at around the levels predicted by standard risk models derived mainly from the experience of the Japanese atomic-bomb survivors acutely exposed principally to gamma radiation. However, the slope of the dose-response for solid cancers expressed in terms of the excess relative risk per unit dose, ERR/Gy, differs between INWORKS and Mayak, such that when compared with the slope derived from the atomic-bomb survivors, INWORKS does not provide obvious support for the use in radiological protection of a dose and dose-rate effectiveness factor greater than one whereas the Mayak workforce apparently does. This difference could be a chance effect, but it could also point to potential problems with these worker studies. Of particular concern is the adequacy of recorded doses received in the early years of operations at older nuclear installations, such as the potential for ‘missed’ photon doses. A further issue is how baseline cancer rates may influence radiation-related excess risks. There is scope for a considerable increase in the statistical power of worker studies, with longer follow-up capturing more deaths and incident cases of cancer, and further workforces being included in collaborative studies, but the difficulties posed by dosimetry questions should not be ignored and need to be the subject of detailed scrutiny.
    • Data protection, information governance and the potential erosion of ethnographic methods in health care?

      Lee, Rebecca R.; orcid: 0000-0002-4559-1647; email: rebecca.lee-4@manchester.ac.uk; McDonagh, Janet E.; Farre, Albert; Peters, Sarah; Cordingley, Lis; Rapley, Tim (2021-11-23)
      Abstract: With the most recent developments to the European General Data Protection Regulations (GDPR) introduced in May 2018, the resulting legislation meant a new set of considerations for study approvers and health‐care researchers. Compared with previous legislation in the UK (The Data Protection Act, 1998), it introduced more extensive and directive principles, requiring anybody ‘processing’ personal data to specifically define how this data will be obtained, stored, used and destroyed. Importantly, it also emphasised the principle of accountability, which meant that data controllers and processors could no longer just state that they planned to adhere to lawful data protection principles, they also had to demonstrate compliance. New questions and concerns around accountability now appear to have increased levels of scrutiny in all areas of information governance (IG), especially with regards to processing confidential patient information. This article explores our experiences of gaining required ethical and regulatory approvals for an ethnographic study in a UK health‐care setting, the implications that the common law duty of confidentiality had for this research, and the ways in which IG challenges were overcome. The purpose of this article was to equip researchers embarking on similar projects to be able to navigate the potentially problematic and complex journey to approval.
    • Assessment of serum total 25-hydroxyvitamin D assays for Vitamin D External Quality Assessment Scheme (DEQAS) materials distributed at ambient and frozen conditions.

      Sempos, Christopher T; Williams, Emma L; Carter, Graham D; Jones, Julia; Camara, Johanna E; Burdette, Carolyn Q; Hahm, Grace; Nalin, Federica; Duewer, David L; Kuszak, Adam J; et al. (2021-11-09)
      The Vitamin D External Quality Assessment Scheme (DEQAS) distributes human serum samples four times per year to over 1000 participants worldwide for the determination of total serum 25-hydroxyvitamin D [25(OH)D)]. These samples are stored at -40 °C prior to distribution and the participants are instructed to store the samples frozen at -20 °C or lower after receipt; however, the samples are shipped to participants at ambient conditions (i.e., no temperature control). To address the question of whether shipment at ambient conditions is sufficient for reliable performance of various 25(OH)D assays, the equivalence of DEQAS human serum samples shipped under frozen and ambient conditions was assessed. As part of a Vitamin D Standardization Program (VDSP) commutability study, two sets of the same nine DEQAS samples were shipped to participants at ambient temperature and frozen on dry ice. Twenty-eight laboratories participated in this study and provided 34 sets of results for the measurement of 25(OH)D using 20 ligand binding assays and 14 liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. Equivalence of the assay response for the frozen versus ambient DEQAS samples for each assay was evaluated using multi-level modeling, paired t-tests including a false discovery rate (FDR) approach, and ordinary least squares linear regression analysis of frozen versus ambient results. Using the paired t-test and confirmed by FDR testing, differences in the results for the ambient and frozen samples were found to be statistically significant at p < 0.05 for four assays (DiaSorin, DIAsource, Siemens, and SNIBE prototype). For all 14 LC-MS/MS assays, the differences in the results for the ambient- and frozen-shipped samples were not found to be significant at p < 0.05 indicating that these analytes were stable during shipment at ambient conditions. Even though assay results have been shown to vary considerably among different 25(OH)D assays in other studies, the results of this study also indicate that sample handling/transport conditions may influence 25(OH)D assay response for several assays. [Abstract copyright: © 2021. This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.]
    • Exploring Consensus on Preventive Measures and Identification of Patients at Risk of Age-Related Macular Degeneration Using the Delphi Process

      García-Layana, Alfredo; email: aglayana@unav.es; Garhöfer, Gerhard; email: gerhard.garhoefer@meduniwien.ac.at; Aslam, Tariq M.; orcid: 0000-0002-9739-7280; email: tariq.aslam@manchester.ac.uk; Silva, Rufino; orcid: 0000-0001-8676-0833; email: rufino.silva@oftalmologia.co.pt; Delcourt, Cécile; orcid: 0000-0002-2099-0481; email: cecile.delcourt@u-bordeaux.fr; Klaver, Caroline C. W.; email: c.c.w.klaver@erasmusmc.nl; Seddon, Johanna M.; email: johanna.seddon@umassmed.edu; Minnella, Angelo M.; email: angelomaria.minnella@unicatt.it (MDPI, 2021-11-20)
      Background: Early identification of AMD can lead to prompt and more effective treatment, better outcomes, and better final visual acuity; several risk scores have been devised to determine the individual level of risk for developing AMD. Herein, the Delphi method was used to provide recommendations for daily practice regarding preventive measures and follow-up required for subjects at low, moderate, and high risk of AMD evaluated with the Simplified Test AMD Risk-assessment Scale (STARS®) questionnaire. Methods: A steering committee of three experts drafted and refined 25 statements on the approach to be recommended in different clinical situations [general recommendations (n = 2), use of evaluation tools (n = 4), general lifestyle advice (n = 3), and AREDS-based nutritional supplementation (n = 5)] with the help of a group of international experts, all co-authors of this paper. Thirty retinal specialists from Europe and the US were chosen based on relevant publications, clinical expertise, and experience in AMD, who then provided their level of agreement with the statements. Statements for which consensus was not reached were modified and voted upon again. Results: In the first round of voting, consensus was reached for 24 statements. After modification, consensus was then reached for the remaining statement. Conclusion: An interprofessional guideline to support preventive measures in patients at risk of AMD based on STARS® scoring has been developed to aid clinicians in daily practice, which will help to optimize preventive care of patients at risk of AMD.
    • Multiplexity analysis of networks using multigraph representations

      Shafie, Termeh; orcid: 0000-0002-8419-8477; email: termeh.shafie@manchester.ac.uk; Schoch, David (Springer Berlin Heidelberg, 2021-09-30)
      Abstract: Multivariate networks comprising several compositional and structural variables can be represented as multigraphs by various forms of aggregations based on vertex attributes. We propose a framework to perform exploratory and confirmatory multiplexity analysis of aggregated multigraphs in order to find relevant associations between vertex and edge attributes. The exploration is performed by comparing frequencies of the different edges within and between aggregated vertex categories, while the confirmatory analysis is performed using derived complexity or multiplexity statistics under different random multigraph models. These statistics are defined by the distribution of edge multiplicities and provide information on the covariation and dependencies of different edges given vertex attributes. The presented approach highlights the need to further analyse and model structural dependencies with respect to edge entrainment. We illustrate the approach by applying it on a well known multivariate network dataset which has previously been analysed in the context of multiplexity.
    • Cardiovascular outcomes in systemic sclerosis with abnormal cardiovascular MRI and serum cardiac biomarkers.

      Dumitru, Raluca B; Bissell, Lesley-Anne; Erhayiem, Bara; Kidambi, Ananth; Dumitru, Ana-Maria H; Fent, Graham; Abignano, Giuseppina; Donica, Helena; Burska, Agata; Greenwood, John P; et al. (2021-10-01)
      <h4>Objectives</h4>To explore the prognostic value of subclinical cardiovascular (CV) imaging measures and serum cardiac biomarkers in systemic sclerosis (SSc) for the development of CV outcomes of primary heart involvement (pHI).<h4>Methods</h4>Patients with SSc with no clinical SSc-pHI and no history of heart disease underwent cardiovascular magnetic resonance (CMR) imaging, and measurement of serum high-sensitivity-troponin I (hs-TnI) and N-terminal-pro-brain natriuretic peptide (NT-proBNP). Follow-up clinical and CV outcome data were recorded. CV outcomes were defined as myocarditis, arrhythmia and/or echocardiographic functional impairment including systolic dysfunction and/or diastolic dysfunction.<h4>Results</h4>Seventy-four patients with a median (IQR) age of 57 (49, 63) years, 32% diffuse cutaneous SSc, 39% interstitial lung disease, 30% Scl70+ were followed up for median (IQR) 22 (15, 54) months. Ten patients developed CV outcomes, comprising one patient with myocarditis and systolic dysfunction and nine arrhythmias: three non-sustained ventricular tachycardia and six supraventricular arrhythmias. The probability of CV outcomes was considerably higher in those with NT-proBNP >125 pg/mL versus normal NT-proBNP (X<sup>2</sup>=4.47, p=0.035). Trend for poorer time-to-event was noted in those with higher extracellular volume (ECV; indicating diffuse fibrosis) and hs-TnI levels versus those with normal values (X<sup>2</sup>=2.659, p=0.103; X<sup>2</sup>=2.530, p=0.112, respectively). In a predictive model, NT-proBNP >125 pg/mL associated with CV outcomes (OR=5.335, p=0.040), with a trend observed for ECV >29% (OR=4.347, p=0.073).<h4>Conclusion</h4>These data indicate standard serum cardiac biomarkers (notably NT-proBNP) and CMR indices of myocardial fibrosis associate with adverse CV outcomes in SSc. This forms the basis to develop a prognostic model in larger, longitudinal studies.