The role of membrane potential dynamics in cell behaviours:investigating the membrane potential dynamics in the Jurkat and HMEC-1 cell lines using the continuous wavelet transform

The role of the plasma membrane potential is most commonly associated with the generation of action potentials in excitable cells, however, experimental evidence suggests that this membrane potential is also linked to various behaviours in all cells (Blackiston et al., 2009). These cell behaviours include cell proliferation, cell migration and even cell survival. The membrane potential has been thought to influence these cell behaviours upstream of the classical transduction pathways. Recent evidence suggests that the membrane potential is dynamic rather than static and this dynamic behaviour may encode information on cell behaviours. The whole cell patch clamping technique coupled with the continuous wavelet transform (CWT) technique was used to investigate the presence of fluctuations and oscillations in the membrane potential of Jurkat cells and HMEC-1 cells. The underlying nature of the membrane potential dynamics of Jurkat cells was investigated by perturbing the extracellular concentration of either K+ , Na+ or Cl- . The membrane potential dynamics of proliferating, non-proliferating and activated Jurkat cells was investigated by either varying the culture medium or treating the cells with the concavalin A mitogen. The membrane potential dynamics of HMEC-1 endothelial cells was also investigated. The magnitude of the static membrane potential of proliferating Jurkat cells was significantly more depolarised that non-proliferating Jurkat cells – a trend which has been observed in a wide range of cell types. The membrane potential dynamics appear to be driven by the conductance of ions rather than the magnitude of the static membrane potential per se. In summary, this thesis has proven that the membrane potential varies with cell state and the CWT technique can be used to interrogate recordings of the membrane potential to ascertain information on the membrane potential dynamics that cannot be currently determined by other techniques

Developing a study intervention: a realist review and consensus workshops to develop the namaste care intervention for people with advanced dementia prior to a feasibility study using a cluster randomised controlled trial in nursing care homes

Background Clear intervention specification is important, but often absent or incomplete in study reports. Namaste Care is a complex intervention for people with advanced dementia, but is not well specified, can be implemented differently, with limited evidence of effect, nor understanding of its optimal delivery. Aims a) To develop a programme theory(ies) of how the Namaste care intervention achieves particular outcomes, and in what circumstances. b) To refine and develop an evidence based Namaste Care intervention specification and training package acceptable to nursing care home staff and families. Methods A two phase approach incorporating both a realist evidence review and consensus methods. Consensus workshops first explored readability, understandability and utility of stimulus materials with Namaste Care naïve care home staff. Next emerging findings from the review were presented to stakeholders (care home staff, volunteers and family carers) with experience of Namaste Care, and nominal group techniques used to identify how intervention materials and resources required to support implementation could be refined. Drawing on nominal group technique analytical methods, analysis considered both the frequency of statement rankings alongside a thematic analysis of reasoning for preferences. Findings Presentation to Namaste Care naive staff resulted in changes to language and clarification of terms such as ‘personal care’. Two consensus workshops (n=15 care home staff participants, n=1 family carer participant, n=1 volunteer participant) further refined materials. An additional section of the intervention guide developed between workshop one and two focused on organisational preparation for Namaste Care implementation. Issues such as intervention timing, frequency, focus and staffing requirements were identified as requiring further specification. Conclusion A careful, staged, process of intervention specification and refinement revealed important issues that required attention. Addressing these before trial commencement could increase the likelihood of intervention fidelit

A four-stage process for intervention description and guide development of a practice-based intervention: refining the Namaste Care intervention implementation specification for people with advanced dementia prior to a feasibility cluster randomised trial

Some interventions are developed from practice, and implemented before evidence of effect is determined, or the intervention is fully specified. An example is Namaste Care, a multi-component intervention for people with advanced dementia, delivered in care home, community, hospital and hospice settings. This paper describes the development of an intervention description, guide and training package to support implementation of Namaste Care within the context of a feasibility trial. This allows fidelity to be determined within the trial, and for intervention users to understand how similar their implementation is to that which was studied. A four-stage approach: a) Collating existing intervention materials and drawing from programme theory developed from a realist review to draft an intervention description. b) Exploring readability, comprehensibility and utility with staff who had not experienced Namaste Care. c) Using modified nominal group techniques with those with Namaste Care experience to refine and prioritise the intervention implementation materials. d) Final refinement with a patient and public involvement panel. Eighteen nursing care home staff, one carer, one volunteer and five members of our public involvement panel were involved across the study steps. A 16-page A4 booklet was designed, with flow charts, graphics and colour coded information to ease navigation through the document. This was supplemented by infographics, and a training package. The guide describes the boundaries of the intervention and how to implement it, whilst retaining the flexible spirit of the Namaste Care intervention. There is little attention paid to how best to specify complex interventions that have already been organically implemented in practice. This four-stage process may have utility for context specific adaptation or description of existing, but untested, interventions. A robust, agreed, intervention and implementation description should enable a high-quality future trial. If an effect is determined, flexible practice implementation should be enabled through having a clear, evidence-based guide

A group intervention to improve quality of life for people with advanced dementia living in care homes: the Namaste feasibility cluster RCT

Background People with advanced dementia who live and die in nursing homes experience variable quality of life, care and dying. There is a need to identify appropriate, cost-effective interventions that facilitate high-quality end-of-life care provision. Objectives To establish the feasibility and acceptability to staff and family of conducting a cluster randomised controlled trial of the Namaste Care intervention for people with advanced dementia in nursing homes. Design The study had three phases: (1) realist review and (2) intervention refinement to inform the design of (3) a feasibility cluster randomised controlled trial with a process evaluation and economic analysis. Clusters (nursing homes) were randomised in a 3 : 1 ratio to intervention or control (usual care). The nature of the intervention meant that blinding was not possible. Setting Nursing homes in England providing care for people with dementia. Participants Residents with advanced dementia (assessed as having a Functional Assessment Staging Test score of 6 or 7), their informal carers and nursing home staff. Intervention Namaste Care is a complex group intervention that provides structured personalised care in a dedicated space, focusing on enhancements to the physical environment, comfort management and sensory engagement. Main outcome measures The two contender primary outcome measures were Comfort Assessment in Dying – End of Life Care in Dementia for quality of dying (dementia) and Quality of Life in Late Stage Dementia for quality of life. The secondary outcomes were as follows: person with dementia, sleep/activity (actigraphy), neuropsychiatric symptoms, agitation and pain; informal carers, satisfaction with care at the end of life; staff members, person-centred care assessment, satisfaction with care at the end of life and readiness for change; and other data – health economic outcomes, medication/service use and intervention activity. Results Phase 1 (realist review; 86 papers) identified that a key intervention component was the activities enabling the development of moments of connection. In phase 2, refinement of the intervention enabled the production of a user-friendly 16-page A4 booklet. In phase 3, eight nursing homes were recruited. Two homes withdrew before the intervention commenced; four intervention and two control homes completed the study. Residents with advanced dementia (n = 32) were recruited in intervention (n = 18) and control (n = 14) homes. Informal carers (total, n = 12: intervention, n = 5; control, n = 7) and 97 staff from eight sites (intervention, n = 75; control, n = 22) were recruited over a 6-month period. Recruitment is feasible. Completion rates of the primary outcome questionnaires were high at baseline (100%) and at 4 weeks (96.8%). The Quality of Life in Late Stage Dementia was more responsive to change over 24 weeks. Even where economic data were missing, these could be collected in a full trial. The intervention was acceptable; the dose varied depending on the staffing and physical environment of each care home. Staff and informal carers reported changes for the person with dementia in two ways: increased social engagement and greater calm. No adverse events related to the intervention were reported. Conclusions A subsequent definitive trial is feasible if there are amendments to the recruitment process, outcome measure choice and intervention specification. Future work In a full trial, consideration is needed of the appropriate outcome measure that is sensitive to different participant responses, and of clear implementation principles for this person-centred intervention in a nursing home context. Trial registration Current Controlled Trials ISRCTN14948133. Funding This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 6. See the NIHR Journals Library website for further project information

Clinical Usefulness of Measuring Red Blood Cell Distribution Width in Patients with Hepatitis B

BACKGROUND: Red blood cell distribution width (RDW), an automated measure of red blood cell size heterogeneity (e.g., anisocytosis) that is largely overlooked, is a newly recognized risk marker in patients with cardiovascular diseases, but its role in persistent viral infection has not been well-defined. The present study was designed to investigate the association between RDW values and different disease states in hepatitis B virus (HBV)-infected patients. In addition, we analyzed whether RDW is associated with mortality in the HBV-infected patients. METHODOLOGY/PRINCIPAL FINDINGS: One hundred and twenty-three patients, including 16 with acute hepatitis B (AHB), 61 with chronic hepatitis B (CHB), and 46 with chronic severe hepatitis B (CSHB), and 48 healthy controls were enrolled. In all subjects, a blood sample was collected at admission to examine liver function, renal function, international normalized ratio and routine hematological testing. All patients were followed up for at least 4 months. A total of 10 clinical chemistry, hematology, and biochemical variables were analyzed for possible association with outcomes by using Cox proportional hazards and multiple regression models. RDW values at admission in patients with CSHB (18.30±3.11%, P<0.001), CHB (16.37±2.43%, P<0.001) and AHB (14.38±1.72%, P<0.05) were significantly higher than those in healthy controls (13.03±1.33%). Increased RDW values were clinically associated with severe liver disease and increased 3-month mortality rate. Multivariate analysis demonstrated that RDW values and the model for end-stage liver disease score were independent predictors for mortality (both P<0.001). CONCLUSION: RDW values are significantly increased in patients with hepatitis B and associated with its severity. Moreover, RDW values are an independent predicting factor for the 3-month mortality rate in patients with hepatitis B

The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase&nbsp;1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation&nbsp;disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age&nbsp; 6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score&nbsp; 652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc&nbsp;= 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N&nbsp;= 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in&nbsp;Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in&nbsp;Asia&nbsp;and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

Global burden of cardiovascular diseases and risk factors, 1990–2019: update from the GBD 2019 study

Cardiovascular diseases (CVDs), principally ischemic heart disease (IHD) and stroke, are the leading cause of global mortality and a major contributor to disability. This paper reviews the magnitude of total CVD burden, including 13 underlying causes of cardiovascular death and 9 related risk factors, using estimates from the Global Burden of Disease (GBD) Study 2019. GBD, an ongoing multinational collaboration to provide comparable and consistent estimates of population health over time, used all available population-level data sources on incidence, prevalence, case fatality, mortality, and health risks to produce estimates for 204 countries and territories from 1990 to 2019. Prevalent cases of total CVD nearly doubled from 271 million (95% uncertainty interval [UI]: 257 to 285 million) in 1990 to 523 million (95% UI: 497 to 550 million) in 2019, and the number of CVD deaths steadily increased from 12.1 million (95% UI:11.4 to 12.6 million) in 1990, reaching 18.6 million (95% UI: 17.1 to 19.7 million) in 2019. The global trends for disability-adjusted life years (DALYs) and years of life lost also increased significantly, and years lived with disability doubled from 17.7 million (95% UI: 12.9 to 22.5 million) to 34.4 million (95% UI:24.9 to 43.6 million) over that period. The total number of DALYs due to IHD has risen steadily since 1990, reaching 182 million (95% UI: 170 to 194 million) DALYs, 9.14 million (95% UI: 8.40 to 9.74 million) deaths in the year 2019, and 197 million (95% UI: 178 to 220 million) prevalent cases of IHD in 2019. The total number of DALYs due to stroke has risen steadily since 1990, reaching 143 million (95% UI: 133 to 153 million) DALYs, 6.55 million (95% UI: 6.00 to 7.02 million) deaths in the year 2019, and 101 million (95% UI: 93.2 to 111 million) prevalent cases of stroke in 2019. Cardiovascular diseases remain the leading cause of disease burden in the world. CVD burden continues its decades-long rise for almost all countries outside high-income countries, and alarmingly, the age-standardized rate of CVD has begun to rise in some locations where it was previously declining in high-income countries. There is an urgent need to focus on implementing existing cost-effective policies and interventions if the world is to meet the targets for Sustainable Development Goal 3 and achieve a 30% reduction in premature mortality due to noncommunicable diseases

Global Burden of Cardiovascular Diseases and Risk Factors, 1990–2019: Update From the GBD 2019 Study

Cardiovascular diseases (CVDs), principally ischemic heart disease (IHD) and stroke, are the leading cause of global mortality and a major contributor to disability. This paper reviews the magnitude of total CVD burden, including 13 underlying causes of cardiovascular death and 9 related risk factors, using estimates from the Global Burden of Disease (GBD) Study 2019. GBD, an ongoing multinational collaboration to provide comparable and consistent estimates of population health over time, used all available population-level data sources on incidence, prevalence, case fatality, mortality, and health risks to produce estimates for 204 countries and territories from 1990 to 2019. Prevalent cases of total CVD nearly doubled from 271 million (95% uncertainty interval [UI]: 257 to 285 million) in 1990 to 523 million (95% UI: 497 to 550 million) in 2019, and the number of CVD deaths steadily increased from 12.1 million (95% UI:11.4 to 12.6 million) in 1990, reaching 18.6 million (95% UI: 17.1 to 19.7 million) in 2019. The global trends for disability-adjusted life years (DALYs) and years of life lost also increased significantly, and years lived with disability doubled from 17.7 million (95% UI: 12.9 to 22.5 million) to 34.4 million (95% UI:24.9 to 43.6 million) over that period. The total number of DALYs due to IHD has risen steadily since 1990, reaching 182 million (95% UI: 170 to 194 million) DALYs, 9.14 million (95% UI: 8.40 to 9.74 million) deaths in the year 2019, and 197 million (95% UI: 178 to 220 million) prevalent cases of IHD in 2019. The total number of DALYs due to stroke has risen steadily since 1990, reaching 143 million (95% UI: 133 to 153 million) DALYs, 6.55 million (95% UI: 6.00 to 7.02 million) deaths in the year 2019, and 101 million (95% UI: 93.2 to 111 million) prevalent cases of stroke in 2019. Cardiovascular diseases remain the leading cause of disease burden in the world. CVD burden continues its decades-long rise for almost all countries outside high-income countries, and alarmingly, the age-standardized rate of CVD has begun to rise in some locations where it was previously declining in high-income countries. There is an urgent need to focus on implementing existing cost-effective policies and interventions if the world is to meet the targets for Sustainable Development Goal 3 and achieve a 30% reduction in premature mortality due to noncommunicable diseases