The role of nitrosative and metabolic stress in vascular cell senescence

Vascular cell senescence has been observed in vascular healing, atheroma and advanced age. Other groups have demonstrated that senescence is a process characterized by metabolic dysfunction. We therefore investigate whether it may occur as a consequence of metabolic stress. Controversy existed as to whether nitric oxide was able to prevent senescence in vascular cells. As nitric oxide is able to inhibit mitochondrial respiration, we investigated its effects both as an oxidant and metabolic stressor. We observed that cells exposed to nitric oxide donors senesce over a concentration range of DETA-NO 0.5-0.75mM or GSNO 1mM, showing an exponential increase in senescence until succumbing to cell death as concentrations of DETA-NO increase. This was confirmed by cell morphology, senescence-associated β-galactosidase activity, total β-galactosidase activity, cell proliferation assays and expression of p16INK4a and p21WAF. We investigated whether this effect could be reproduced by cells induced to express iNOS in vitro. Using these tools, we investigated the mechanism of NO-induced senescence looking at soluble guanylate cyclase activation, increased generation of ROS, protein transnitrosation and glutathione depletion. We investigated ways in which nitric oxide-induced senescence could be circumvented by using antioxidants (NAC, selenomethionine, uric acid), activating AMP kinase with metformin and AICAR and reducing protein transnitrosation by exposing the cells to cold light. We used pharmacological means to mimic lysosomal dysfunction and to stimulate autophagy. My findings show that nitric oxide can cause senescence in vascular cells by a mechanism that involves protein transnitrosation. The effect of nitric oxide on senescence is independent of ROS generation, AMP kinase activation, soluble guanylate cyclase activation and glutathione depletion. My findings may have important implications in vascular disease, particularly in cases of short periods of high nitric oxide production, such as sepsis, but also in the case of low-grade chronic inflammation such as that seen in atherosclerosis. However, their physiological relevance needs to be confirmed. The pathway by which protein transnitrosation induces senescence has yet to be fully elucidated

Rational Topological Design for Fluorescence Enhancement upon Aggregation of Distyrylfuran Derivatives

A series of 2,5-distyrylfuran derivatives bearing pentafluorophenyl- and cyanovinyl units have been synthesized for aggregation-induced emission (AIE). The effect of the type and extent of the supramolecular connections on the AIE of the furan derivatives were examined and correlated with their X-ray crystal structures. It was found that the simultaneous presence of cyano and perfluorophenyl units strongly enhances the fluorescence upon aggregation. Single-crystal X-ray diffraction analysis confirmed that C — H⋅⋅⋅F, F⋅⋅⋅F, C — H⋅⋅⋅nitrile, Ar⋅⋅⋅ArF (Ar=aryl, ArF=fluoroaryl), and nitrile⋅⋅⋅ArF intra- and intermolecular interactions drive the topology of the molecule and that solid-state supramolecular contacts favor AIE of the furan derivatives

Safety and feasibility of sublingual microcirculation assessment in the emergency department for civilian and military patients with traumatic haemorrhagic shock: a prospective cohort study

OBJECTIVES: Sublingual microcirculatory monitoring for traumatic haemorrhagic shock (THS) may predict clinical outcomes better than traditional blood pressure and cardiac output, but is not usually performed until the patient reaches the intensive care unit (ICU), missing earlier data of potential importance. This pilot study assessed for the first time the feasibility and safety of sublingual video-microscopy for THS in the emergency department (ED), and whether it yields useable data for analysis. SETTING: A safety and feasibility assessment was undertaken as part of the prospective observational MICROSHOCK study; sublingual video-microscopy was performed at the UK-led Role 3 medical facility at Camp Bastion, Afghanistan, and in the ED in 3 UK Major Trauma Centres. PARTICIPANTS: There were 15 casualties (2 military, 13 civilian) who presented with traumatic haemorrhagic shock with a median injury severity score of 26. The median age was 41; the majority (n=12) were male. The most common injury mechanism was road traffic accident. PRIMARY AND SECONDARY OUTCOME MEASURES: Safety and feasibility were the primary outcomes, as measured by lack of adverse events or clinical interruptions, and successful acquisition and storage of data. The secondary outcome was the quality of acquired video clips according to validated criteria, in order to determine whether useful data could be obtained in this emergency context. RESULTS: Video-microscopy was successfully performed and stored for analysis for all patients, yielding 161 video clips. There were no adverse events or episodes where clinical management was affected or interrupted. There were 104 (64.6%) video clips from 14 patients of sufficient quality for analysis. CONCLUSIONS: Early sublingual microcirculatory monitoring in the ED for patients with THS is safe and feasible, even in a deployed military setting, and yields videos of satisfactory quality in a high proportion of cases. Further investigations of early microcirculatory behaviour in this context are warranted. TRIAL REGISTRATION NUMBER: NCT02111109

Improving uptake of hepatitis B and hepatitis C testing in South Asian migrants in community and faith settings using educational interventions - a prospective descriptive study

BACKGROUND: Chronic viral hepatitis (CVH) is a leading contributor to the UK liver disease epidemic, with global migration from high-prevalence areas (e.g. South Asia-SA). Despite international guidance for testing high-risk groups in line with elimination targets, there is no consensus on how to achieve this. OBJECTIVES: (i) Feasibility of recruiting SA migrants to view an educational film on CVH (ii) Effectiveness of the film in promoting testing, knowledge of CVH (iii) Methodological issues relevant to scale-up to randomized trial. METHODS: We recruited SA migrants to view the film (intervention) in community venues (primary care, religious, community), offering dried-blood spot CVH testing immediately afterwards. Pre/post-film questionnaires assessed the interventions effectiveness. RESULTS: Two hundred and nineteen first generation migrants >18yrs (53% female) were recruited to view the film;184 (84%) underwent CVH testing (HBc Ab or HCV Ab positive, demonstrating exposure in 8.5%) at the following sites: n = 112 (51%) religious, n = 98(45%) community, and primary care, n = 9 (4%). Pre (n = 173, 79%) and post (n = 154, 70%) intervention questionnaires were completed. CONCLUSIONS: We demonstrate the feasibility of recruiting first generation migrants to participate in a community-based educational film, promoting CVH testing in this higher-risk group, confirming value of developing interventions to facilitate global WHO plan for targeted case finding, elimination and future randomized controlled trial. We highlight the importance of culturally relevant interventions including faith, and culturally sensitive settings appearing to minimize logistical issues effective at engaging minority groups and allowing ease of access to individuals 'at risk'

Pain assessment tools in paediatric palliative care: A systematic review of psychometric properties and recommendations for clinical practice

Background: Assessing pain in infants, children and young people with life-limiting conditions remains a challenge due to diverse patient conditions, types of pain and often a reduced ability or inability of patients to communicate verbally. Aim: To systematically identify pain assessment tools that are currently used in paediatric palliative care and examine their psychometric properties and feasibility and make recommendations for clinical practice. Design: A systematic literature review and evaluation of psychometric properties of pain assessment tools of original peer-reviewed research published from inception of data sources to April 2021. Data sources: PsycINFO via ProQuest, Web of Science Core, Medline via Ovid, EMBASE, BIOSIS and CINAHL were searched from inception to April 2021. Hand searches of reference lists of included studies and relevant reviews were performed. Results: From 1168 articles identified, 201 papers were selected for full-text assessment. Thirty-four articles met the eligibility criteria and we examined the psychometric properties of 22 pain assessment tools. Overall, the Faces Pain Scale-Revised (FPS-R) had high cross-cultural validity, construct validity (hypothesis testing) and responsiveness; while the Faces, Legs, Activity, Cry and Consolability (FLACC) scale and Paediatric Pain Profile (PPP) had high internal consistency, criterion validity, reliability and responsiveness. The number of studies per psychometric property of each pain assessment tool was limited and the methodological quality of included studies was low. Conclusion: Balancing aspects of feasibility and psychometric properties, the FPS-R is recommended for self-assessment, and the FLACC scale/FLACC Revised and PPP are the recommended observational tools in their respective age groups

Dilatation in the femoral vascular bed does not cause retrograde relaxation of the iliac artery in the anaesthetized pig

Aim:  We tested the hypothesis that dilatation of a feeding artery may be elicited by transmission of a signal through the tissue of the arterial wall from a vasodilated peripheral vascular bed. Methods:  In eight pentobarbital anaesthetized pigs, acetylcholine (ACh, an endothelium-dependent vasodilator) was injected intra-arterially above (upstream) and below (downstream) a test segment of the left iliac artery, the diameter of which was measured continuously by sonomicrometry. Results:  Under control conditions, ACh injections upstream and downstream of the test segment caused dilatation. Downstream injection dilated the peripheral arterioles, resulting in increased blood flow and proximal dilatation. This is a shear stress, nitric oxide (NO)-dependent response. The experiment was then repeated after applying a stenosis to prevent the increased flow caused by downstream injection of ACh; the stenosis was placed either above the site of diameter measurement to allow retrograde conduction, or below that site to prevent distally injected ACh reaching the measurement site. Under these conditions, downstream injection of ACh had a minimal effect on the shear stress of the test segment with no increase in test segment diameter. This was not due to endothelial damage or dysfunction as injection of ACh upstream still caused a large increase in test segment diameter. Conclusions:  Our results indicate that dilatation of the feeding artery of a vasodilated bed is caused by increased shear stress within the feeding artery and not via a signal transmitted through the arterial wall from below

Topological and packing mode modification for solid-state emission enhancement of bis(perfluorostyryl)furan derivatives

An unsymmetric bis(perfluorostyryl)furan with a cyanovinyl unit was prepared (F1). Its crystallographic structure was resolved along with its cyano vinylene (1) and unsubstituted (2) aldehyde precursors. F1 was found to form ribbons involving C–H⋯F interactions, while also having multiple intermolecular contacts, including C–F⋯Fπ and π–π interactions. These contacts also occurred when F1 aggregated in 9 : 1 water/THF mixtures. When the supramolecular contacts are engaged, the emission intensity of F1 increases, with absolute emission yields of 9 and 25% occurring in aggregates and powder, respectively

Total ankle replacement versus arthrodesis (TARVA): protocol for a multicentre randomised controlled trial.

INTRODUCTION: Total ankle replacement (TAR) or ankle arthrodesis (fusion) is the main surgical treatments for end-stage ankle osteoarthritis (OA). The popularity of ankle replacement is increasing while ankle fusion rates remain static. Both treatments have efficacy but to date all studies comparing the 2 have been observational without randomisation, and there are no published guidelines as to the most appropriate management. The TAR versus arthrodesis (TARVA) trial aims to compare the clinical and cost-effectiveness of TAR against ankle arthrodesis in the treatment of end-stage ankle OA in patients aged 50-85 years. METHODS AND ANALYSIS: TARVA is a multicentre randomised controlled trial that will randomise 328 patients aged 50-85 years with end-stage ankle arthritis. The 2 arms of the study will be TAR or ankle arthrodesis with 164 patients in each group. Up to 16 UK centres will participate. Patients will have clinical assessments and complete questionnaires before their operation and at 6, 12, 26 and 52 weeks after surgery. The primary clinical outcome of the study is a validated patient-reported outcome measure, the Manchester Oxford foot questionnaire, captured preoperatively and 12 months after surgery. Secondary outcomes include quality-of-life scores, complications, revision, reoperation and a health economic analysis. ETHICS AND DISSEMINATION: The protocol has been approved by the National Research Ethics Service Committee (London, Bloomsbury 14/LO/0807). This manuscript is based on V.5.0 of the protocol. The trial findings will be disseminated through peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT02128555

Single-Nucleus RNA-Seq Is Not Suitable for Detection of Microglial Activation Genes in Humans

Single-nucleus RNA sequencing (snRNA-seq) is used as an alternative to single-cell RNA-seq, as it allows transcriptomic profiling of frozen tissue. However, it is unclear whether snRNA-seq is able to detect cellular state in human tissue. Indeed, snRNA-seq analyses of human brain samples have failed to detect a consistent microglial activation signature in Alzheimer's disease. Our comparison of microglia from single cells and single nuclei of four human subjects reveals that, although most genes show similar relative abundances in cells and nuclei, a small population of genes (∼1%) is depleted in nuclei compared to whole cells. This population is enriched for genes previously implicated in microglial activation, including APOE, CST3, SPP1, and CD74, comprising 18% of previously identified microglial-disease-associated genes. Given the low sensitivity of snRNA-seq to detect many activation genes, we conclude that snRNA-seq is not suited for detecting cellular activation in microglia in human disease