Deep, hot, ancient melting recorded by ultralow oxygen fugacity in peridotites.

The oxygen fugacity (fO2) of convecting upper mantle recorded by ridge peridotites varies by more than four orders of magnitude1-3. Although much attention has been given to mechanisms that drive variations in mantle fO2 between tectonic settings1,3,4 and to comparisons of fO2 between modern rocks and ancient-mantle-derived rocks5-10, comparatively little has been done to understand the origins of the high variability in fO2 recorded by peridotites from modern mid-ocean ridge settings. Here we report the petrography and geochemistry of peridotites from the Gakkel Ridge and East Pacific Rise (EPR), including 16 new high-precision determinations of fO2. Refractory peridotites from the Gakkel Ridge record fO2 more than four orders of magnitude below the mantle average. With thermodynamic and mineral partitioning modelling, we show that excursions to ultralow fO2 can be produced by large degrees of melting at high potential temperature (Tp), beginning in the garnet field and continuing into the spinel field-conditions met during the generation of ancient komatiites but not modern basalts. This does not mean that ambient convecting upper mantle had a lower ferric to ferrous ratio in Archaean times than today nor that modern melting in the garnet field at hotspots produce reduced magmas. Instead, it implies that rafts of ancient, refractory, ultrareduced mantle continue to circulate in the modern mantle while contributing little to modern ridge volcanism.

Investigating the association between nitrate dosing and nitrite generation by the human oral microbiota in continuous culture.

The generation of nitrite by the oral microbiota is believed to contribute to healthy cardiovascular function, with oral nitrate reduction to nitrite associated with systemic blood pressure regulation. There is the potential to manipulate the composition or activities of the oral microbiota to a higher nitrate-reducing state through nitrate supplementation. The current study examined microbial community composition and enzymatic responses to nitrate supplementation in sessile oral microbiota grown in continuous culture. Nitrate reductase (NaR) activity and nitrite concentrations were not significantly different to tongue-derived inocula in model biofilms. These were generally dominated by Streptococcus spp., initially, and a single nitrate supplementation resulted in the increased relative abundance of the nitrate-reducing genera Veillonella, Neisseria, and Proteus spp. Nitrite concentrations increased concomitantly and continued to increase throughout oral microbiota development. Continuous nitrate supplementation, over a 7-day period, was similarly associated with an elevated abundance of nitrate-reducing taxa and increased nitrite concentration in the perfusate. In experiments in which the models were established in continuous low or high nitrate environments, there was an initial elevation in nitrate reductase, and nitrite concentrations reached a relatively constant concentration over time similar to the acute nitrate challenge with a similar expansion of Veillonella and Neisseria. In summary, we have investigated nitrate metabolism in continuous culture oral biofilms, showing that nitrate addition increases nitrate reductase activity and nitrite concentrations in oral microbiota with the expansion of putatively NaR-producing taxa.IMPORTANCEClinical evidence suggests that blood pressure regulation can be promoted by nitrite generated through the reduction of supplemental dietary nitrate by the oral microbiota. We have utilized oral microbiota models to investigate the mechanisms responsible, demonstrating that nitrate addition increases nitrate reductase activity and nitrite concentrations in oral microbiota with the expansion of nitrate-reducing taxa.

Early episodes of high-pressure core formation preserved in plume mantle.

The decay of short-lived iodine (I) and plutonium (Pu) results in xenon (Xe) isotopic anomalies in the mantle that record Earth's earliest stages of formation. Xe isotopic anomalies have been linked to degassing during accretion, but degassing alone cannot account for the co-occurrence of Xe and tungsten (W) isotopic heterogeneity in plume-derived basalts and their long-term preservation in the mantle. Here we describe measurements of I partitioning between liquid Fe alloys and liquid silicates at high pressure and temperature and propose that Xe isotopic anomalies found in modern plume rocks (that is, rocks with elevated 3He/4He ratios) result from I/Pu fractionations during early, high-pressure episodes of core formation. Our measurements demonstrate that I becomes progressively more siderophile as pressure increases, so that portions of mantle that experienced high-pressure core formation will have large I/Pu depletions not related to volatility. These portions of mantle could be the source of Xe and W anomalies observed in modern plume-derived basalts. Portions of mantle involved in early high-pressure core formation would also be rich in FeO, and hence denser than ambient mantle. This would aid the long-term preservation of these mantle portions, and potentially points to their modern manifestation within seismically slow, deep mantle reservoirs with high 3He/4He ratios.

Co-development and testing of an extended community pharmacy model of service delivery for managing osteoarthritis: protocol for a sequential, multi-methods study (PharmOA).

BACKGROUND: Osteoarthritis is a common, painful and disabling long-term condition. Delivery of high-quality guideline-informed osteoarthritis care that successfully promotes and maintains supported self-management is imperative. However, osteoarthritis care remains inconsistent, including under use of core non-pharmacological approaches of education, exercise and weight loss. Community pharmacies are an accessible healthcare provider. United Kingdom government initiatives are promoting their involvement in a range of long-term conditions, including musculoskeletal conditions. It is not known what an enhanced community pharmacy role for osteoarthritis care should include, what support is needed to deliver such a role, and whether it would be feasible and acceptable to community pharmacy teams. In this (PharmOA) study, we aim to address these gaps, and co-design and test an evidence-based extended community pharmacy model of service delivery for managing osteoarthritis. METHODS: Informed by the Theoretical Domains Framework, Normalisation Process Theory, and the Medical Research Council (MRC) framework for developing complex interventions, we will undertake a multi-methods study involving five phases: 1. Systematic review to summarise currently available evidence on community pharmacy roles in supporting adults with osteoarthritis and other chronic (non-cancer) pain. 2. Cross-sectional surveys and one-to-one qualitative interviews with patients, healthcare professionals and pharmacy staff to explore experiences of current, and potential extended community pharmacy roles, in delivering osteoarthritis care. 3. Stakeholder co-design to: a) agree on the extended role of community pharmacies in osteoarthritis care; b) develop a model of osteoarthritis care within which the extended roles could be delivered (PharmOA model of service delivery); and c) refine existing tools to support community pharmacies to deliver extended osteoarthritis care roles (PharmOA tools). 4. Feasibility study to explore the acceptability and feasibility of the PharmOA model of service delivery and PharmOA tools to community pharmacy teams. 5. Final stakeholder workshop to: a) finalise the PharmOA model of service delivery and PharmOA tools, and b) if applicable, prioritise recommendations for its wider future implementation. DISCUSSION: This novel study paves the way to improving access to and availability of high-quality guideline-informed, consistent care for people with osteoarthritis from within community pharmacies.

The carbon content of Earth and its core.

Earth's core is likely the largest reservoir of carbon (C) in the planet, but its C abundance has been poorly constrained because measurements of carbon's preference for core versus mantle materials at the pressures and temperatures of core formation are lacking. Using metal-silicate partitioning experiments in a laser-heated diamond anvil cell, we show that carbon becomes significantly less siderophile as pressures and temperatures increase to those expected in a deep magma ocean during formation of Earth's core. Based on a multistage model of core formation, the core likely contains a maximum of 0.09(4) to 0.20(10) wt% C, making carbon a negligible contributor to the core's composition and density. However, this accounts for ∼80 to 90% of Earth's overall carbon inventory, which totals 370(150) to 740(370) ppm. The bulk Earth's carbon/sulfur ratio is best explained by the delivery of most of Earth's volatiles from carbonaceous chondrite-like precursors.

Chronic developmental hypoxia alters mitochondrial oxidative capacity and reactive oxygen species production in the fetal rat heart in a sex-dependent manner.

Insufficient oxygen supply (hypoxia) during fetal development leads to cardiac remodeling and a predisposition to cardiovascular disease in later life. Previous work has shown hypoxia causes oxidative stress in the fetal heart and alters the activity and expression of mitochondrial proteins in a sex-dependent manner. However, the functional effects of these modifications on mitochondrial respiration remain unknown. Furthermore, while maternal antioxidant treatments are emerging as a promising new strategy to protect the hypoxic fetus, whether these treatments convey similar protection to cardiac mitochondria in the male or female fetus has not been investigated. Therefore, using an established rat model, we measured the sex-dependent effects of gestational hypoxia and maternal melatonin treatment on fetal cardiac mitochondrial respiration, reactive oxygen species (ROS) production, and lipid peroxidation. Pregnant Wistar rats were subjected to normoxia or hypoxia (13% oxygen) during gestational days (GDs) 6-20 (term ~22 days) with or without melatonin treatment (5 µg/ml in maternal drinking water). On GD 20, mitochondrial aerobic respiration and H2 O2 production were measured in fetal heart tissue, together with lipid peroxidation and citrate synthase (CS) activity. Gestational hypoxia reduced maternal body weight gain (p < .01) and increased placental weight (p < .05) but had no effect on fetal weight or litter size. Cardiac mitochondria from male but not female fetuses of hypoxic pregnancy had reduced respiratory capacity at Complex II (CII) (p < .05), and an increase in H2 O2 production/O2 consumption (p < .05) without any changes in lipid peroxidation. CS activity was also unchanged in both sexes. Despite maternal melatonin treatment increasing maternal and fetal plasma melatonin concentration (p < .001), melatonin treatment had no effect on any of the mitochondrial parameters investigated. To conclude, we show that gestational hypoxia leads to ROS generation from the mitochondrial electron transport chain and affects fetal cardiac mitochondrial respiration in a sex-dependent manner. We also show that maternal melatonin treatment had no effect on these relationships, which has implications for the development of future therapies for hypoxic pregnancies.

Using social media for patient and public involvement and engagement in health research: The process and impact of a closed Facebook group.

BACKGROUND: As part of a multifaceted approach to patient and public involvement and engagement (PPIE), alongside traditional methods, a closed Facebook group was established to facilitate PPIE feedback on various aspects of a project that used video-recording to examine risk communication in NHS Health Checks between June 2017 and July 2019. OBJECTIVE: To explore the process and impact of conducting PPIE through a closed Facebook group and to identify the associated benefits and challenges. METHODS: Supported by reflections and information from project meetings used to document how this engagement informed the project, we describe the creation and maintenance of the Facebook Group and how feedback from the group members was obtained. Facebook data were used to investigate levels and types of engagement in the closed Facebook group. We reflect on the challenges of using this method of engaging the public in health research. RESULTS: A total of 289 people joined the 'Risk Communication of Cardiovascular disease in NHS Health Checks' PPIE closed Facebook group. They provided feedback, which was used to inform aspects of the study, including participant-facing documents, recruitment, camera position and how the methodology being used (video-recorded Health Checks and follow-up interviews) would be received by the public. DISCUSSION: Using a closed Facebook group to facilitate PPIE offered a flexible approach for both researchers and participants, enabled a more inclusive method to PPIE (compared with traditional methods) and allowed rapid feedback. Challenges included maintaining the group, which was more labour intensive than anticipated and managing members' expectations. Suggestions for best practice include clear communication about the purpose of the group, assigning a group co-ordinator to be the main point of contact for the group, and a research team who can dedicate the time necessary to maintain the group. CONCLUSION: The use of a closed Facebook group can facilitate effective PPIE. Its flexibility can be beneficial for researchers, patients and public who wish to engage in the research process. Dedicated time for sustained group engagement is important. PATIENT OR PUBLIC CONTRIBUTION: Patient representatives were engaged with the development of the research described in this paper and a patient representative reviewed the manuscript.

Acceptability of, and preferences for, remote consulting during COVID-19 among older patients with two common long-term musculoskeletal conditions: findings from three qualitative studies and recommendations for practice.

BACKGROUND: Guidance for choosing face-to-face vs remote consultations (RCs) encourages clinicians to consider patient preferences, however, little is known about acceptability of, and preferences for RCs, particularly amongst patients with musculoskeletal conditions. This study aimed to explore the acceptability of, and preferences for, RC among patients with osteoporosis and rheumatoid arthritis. METHODS: Three UK qualitative studies, exploring patient experiences of accessing and receiving healthcare, undertaken during the pandemic, with people with osteoporosis and rheumatoid arthritis. Study team members agreed a consistent approach to conduct rapid deductive analysis using the Theoretical Framework of Acceptability (TFA) on transcripts from each data set relating to RC, facilitated by group meetings to discuss interpretations. Findings from the three studies were pooled. RESULTS: Findings from 1 focus group and 64 interviews with 35 people were included in the analysis. Participants' attitudes to RC, views on fairness (ethicality) and sense-making (intervention coherence) varied according to their needs within the consultation and views of the pandemic. Some participants valued the reduced burden associated with RC, while others highly valued non-verbal communication and physical examination associated with face-to-face consults (opportunity costs). Some participants described low confidence (self-efficacy) in being able to communicate in RCs and others perceived RCs as ineffective, in part due to suboptimal communication. CONCLUSIONS: Acceptability of, and preferences for RC appear to be influenced by societal, healthcare provider and personal factors and in this study, were not condition-dependant. Remote care by default has the potential to exacerbate health inequalities and needs nuanced implementation.

Co-prescription of gabapentinoids and opioids among adults with and without osteoarthritis in the United Kingdom between 1995 and 2017.

OBJECTIVES: To produce national and regional estimates and trends for gabapentinoid-opioid co-prescribing rates in patients with OA, both in absolute terms and relative to matched controls without OA. METHODS: Using the UK Clinical Practice Research Datalink database we first constructed age-sex-practice-date 1:1 matched cohorts of patients aged ≥40 years with and without a new diagnosis of OA between 1995-2017 and estimated the relative incidence of a first gabapentinoid prescription. Incident gabapentinoid users in both cohorts were followed to estimate and compare the event rate of gabapentinoid-opioid co-prescription (prescription from both classes within the same 28-day window). RESULTS: The incidence of first gabapentinoid prescription was 3-fold higher in patients with OA than in matched controls [n = 215 357; incidence rate ratio (IRR) 2.93; 95% CI: 2.87, 3.00]. Among incident gabapentinoid users with OA (n = 27 374, median follow-up 3.9 years) the event rate of gabapentinoid-opioid co-prescription was 4.03 (4.02-4.05) per person-year. The rate was higher in OA patients classed as long-term gabapentinoid users (6.24; 6.22-6.26). These rates were significantly higher than in incident gabapentinoid users without OA [adjusted-IRR: 1.29 (1.28-1.30)]. This elevated risk was observed across age, sex, geographic regions, and calendar years, when restricted to strong opioids and to long-term gabapentinoid users, and when co-prescription was defined as within 14 days and same-day prescribing. CONCLUSIONS: Patients with OA not only have a higher risk of being prescribed a gabapentinoid but, once prescribed a gabapentinoid, are also at greater risk of opioid co-prescription. Strict restriction of gabapentinoid-opioid co-prescription, and improved access to, and uptake of, effective non-pharmacological and surgical alternatives for OA are required.

Acceptability of physician associate interns in primary care: results from a service evaluation.

BACKGROUND: Physician associates (PA) form part of the policy-driven response to increased primary care demand and a general practitioner (GP) recruitment and retention crisis. However, they are novel to the primary care workforce and have limitations, for example, they cannot prescribe. The novel 1 year Staffordshire PA Internship (SPAI) scheme, introduced in 2017, was established to support the integration of PAs into primary care. PA interns concurrently worked in primary and secondary care posts, with protected weekly primary care focussed education sessions. This evaluation established the acceptability of PA interns within primary care. METHODS: All ten PAs from the first two SPAI cohorts, the nine host practices (supervising GPs and practice managers) and host practice patients were invited to participate in the evaluation. A conceptual framework for implementing interventions in primary care informed data collection and analysis. Data were gathered at three time points over the internship from practices, through discussions with the supervising GP and/or practice manager, and from the PAs via discussion groups. To enrich discussion data, PA and practices were sent brief surveys requesting information on PA/practice characteristics and PA primary care roles. Patient acceptability data were collected by the host practices. Participation at every stage was optional. RESULTS: By evaluation end, eight PAs had completed the internship. Seven PAs and six practices provided data at every time point. Five practices provided patient acceptability data. Overall PA interns were acceptable to practices and patients, however ambiguity about the PA role and how best to communicate and operationalise PA roles was revealed. An expectation-preparedness gap resulted in PAs needing high levels of supervision early within the internship. SPAI facilitated closure of the expectation-preparedness gap and its funding arrangements made the high supervision requirements more acceptable to practices. CONCLUSIONS: The test-of-concept SPAI successfully integrated new PAs into primary care. However, the identified challenges risk undermining PAs roles in primary care before they have attained their full potential. Nationally, workforce leaders should develop approaches to support new PAs into primary care, including commitments to longer-term, sustainable, cohesive and appropriately funded schemes, including structured and standardised education and supervision.

Improving osteoarthritis management in primary healthcare: results from a quasi-experimental study.

BACKGROUND: To improve quality of care for patients with hip and knee osteoarthritis (OA), general practitioners (GPs) and physiotherapists (PTs) in a Norwegian municipality initiated an intervention. The intervention aimed to increase provision of core OA treatment (information, exercise, and weight control) prior to referral for surgery, rational use of imaging for assessing OA and improve communication between healthcare professionals. This study assessed the effectiveness of this intervention. METHODS: Forty-eight PTs and one hundred one GPs were invited to the intervention that included two interactive workshops outlining best practice and an accompanying template for PT discharge reports. Using interrupted time series research design, the study period was divided into three: pre-implementation, transition (implementation) and post-implementation. Comparing the change between pre- and post-implementation, the primary outcome was patient-reported quality of OA care measured with the OsteoArthritis Quality Indicator questionnaire. Secondary outcomes were number of PT discharge reports, information included in GP referral letters to orthopaedic surgeon, the proportion of GP referral letters indicating use of core treatment, and the use of imaging within OA assessment. Analyses involved linear mixed and logistic regression models. RESULTS: The PT workshop had 30 attendees, and 31 PTs and 33 GPs attended the multidisciplinary workshop. Two hundred eight and one hundred twenty-five patients completed the questionnaire during pre- and post-implementation, respectively. The adjusted model showed a small, statistically non-significant, increase in mean total score for quality of OA care (mean change = 4.96, 95% CI -0.18, 10.12, p:0.057), which was mainly related to items on OA core treatment. Patients had higher odds of reporting receipt of information on treatment alternatives (odds ratio (OR) 1.9, 95% CI 1.08, 3.24) and on self-management (OR 2.4, 95% CI 1.33, 4.32) in the post-implementation phase. There was a small, statistically non-significant, increase in the proportion of GP referral letters indicating prior use of core treatment modalities. There were negligible changes in the number of PT discharge reports, in the information included in the GP referral letters, and in the use of imaging for OA assessment. CONCLUSION: This study suggests that a primary care intervention including two inter-active workshops can shift the quality of care towards best practice recommendations. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02876120 .

Association between received treatment elements and satisfaction with care for patients with knee osteoarthritis seen in general practice in Denmark.

OBJECTIVE: While education, exercise, and weight reduction when indicated, are recommended first-line treatments for knee osteoarthritis patients, they remain poorly implemented in favour of pain killer treatment, imaging and referral to surgery. A reason could be that patients are more satisfied with receiving these adjunctive treatment elements. This study aimed to investigate the associations between the received elements of care and the patient's satisfaction with the care for knee osteoarthritis in general practice. DESIGN: Cross-sectional study. SETTING: A Danish general practice. SUBJECTS: All consecutive patients ≥30 years of age who consulted the general practitioner (GP) with chronic knee complaints during 18 months and who replied to a mailed questionnaire (n = 136). MAIN OUTCOME MEASURES: The questionnaire addressed patient's knee-related quality of life, and overall satisfaction with care, as well as reception of seven types of information, which are known quality indicators. Information on reception of adjunctive treatment elements was obtained from electronic medical records. RESULTS: Patient satisfaction (versus neutrality/dissatisfaction) was positively associated with reception of information on: physical activity and exercise (relative risks [RR] 1.38, 95% bootstrap percentile interval [BPI] 1.02-4.33), and the relationship between weight and osteoarthritis (1.38, 1.01-4.41). No significant associations were found for the five remaining types of information and all the adjunctive treatment elements. CONCLUSION: Providing information as education to patients with knee osteoarthritis as part of the treatment is positively associated with satisfaction with care.KEY POINTSGeneral practitioners worry about the doctor-patient relationship when addressing recommended lifestyle changes. However, this study revealed:•Patients in general practice with knee osteoarthritis are satisfied with care after having received information on lifestyle changes, such as exercise and the relationship between weight and osteoarthritis.•Patient satisfaction was not associated with the reception of adjunctive treatment elements for osteoarthritis.

Enhanced Nitrite-Mediated Relaxation of Placental Blood Vessels Exposed to Hypoxia Is Preserved in Pregnancies Complicated by Fetal Growth Restriction.

Nitric oxide (NO) is essential in the control of fetoplacental vascular tone, maintaining a high flow-low resistance circulation that favors oxygen and nutrient delivery to the fetus. Reduced fetoplacental blood flow is associated with pregnancy complications and is one of the major causes of fetal growth restriction (FGR). The reduction of dietary nitrate to nitrite and subsequently NO may provide an alternative source of NO in vivo. We have previously shown that nitrite induces vasorelaxation in placental blood vessels from normal pregnancies, and that this effect is enhanced under conditions of hypoxia. Herein, we aimed to determine whether nitrite could also act as a vasodilator in FGR. Using wire myography, vasorelaxant effects of nitrite were assessed on pre-constricted chorionic plate arteries (CPAs) and veins (CPVs) from normal and FGR pregnancies under normoxic and hypoxic conditions. Responses to the NO donor, sodium nitroprusside (SNP), were assessed in parallel. Nitrate and nitrite concentrations were measured in fetal plasma. Hypoxia significantly enhanced vasorelaxation to nitrite in FGR CPAs (p < 0.001), and in both normal (p < 0.001) and FGR (p < 0.01) CPVs. Vasorelaxation to SNP was also potentiated by hypoxia in both normal (p < 0.0001) and FGR (p < 0.01) CPVs. However, compared to vessels from normal pregnancies, CPVs from FGR pregnancies showed significantly lower reactivity to SNP (p < 0.01). Fetal plasma concentrations of nitrate and nitrite were not different between normal and FGR pregnancies. Together, these data show that nitrite-mediated vasorelaxation is preserved in FGR, suggesting that interventions targeting this pathway have the potential to improve fetoplacental blood flow in FGR pregnancies.

Beetroot juice lowers blood pressure and improves endothelial function in pregnant eNOS-/- mice: importance of nitrate-independent effects.

KEY POINTS: Maternal hypertension is associated with increased rates of pregnancy pathologies, including fetal growth restriction, due at least in part to reductions in nitric oxide (NO) bioavailability and associated vascular dysfunction. Dietary nitrate supplementation, from beetroot juice (BRJ), has been shown to increase NO bioavailability and improve cardiovascular function in both preclinical and clinical studies. This study is the first to investigate effects of dietary nitrate supplementation in a pregnant animal model. Importantly, the effects of nitrate-containing BRJ were compared with both 'placebo' (nitrate-depleted) BRJ as well as water to control for potential nitrate-independent effects. Our data show novel, nitrate-independent effects of BRJ to lower blood pressure and improve vascular function in endothelial nitric oxide synthase knockout (eNOS-/- ) mice. These findings suggest potential beneficial effects of BRJ supplementation in pregnancy, and emphasize the importance of accounting for nitrate-independent effects of BRJ in study design and interpretation. ABSTRACT: Maternal hypertension is associated with adverse pregnancy outcomes, including fetal growth restriction (FGR), due in part to reductions in nitric oxide (NO) bioavailability. We hypothesized that maternal dietary nitrate administration would increase NO bioavailability to reduce systolic blood pressure (SBP), improve vascular function and increase fetal growth in pregnant endothelial NO synthase knockout (eNOS-/- ) mice, which exhibit hypertension, endothelial dysfunction and FGR. Pregnant wildtype (WT) and eNOS-/- mice were supplemented with nitrate-containing beetroot juice (BRJ+) from gestational day (GD) 12.5. Control mice received an equivalent dose of nitrate-depleted BRJ (BRJ-) or normal drinking water. At GD17.5, maternal SBP was measured; at GD18.5, maternal nitrate/nitrite concentrations, uterine artery (UtA) blood flow and endothelial function were assessed, and pregnancy outcomes were determined. Plasma nitrate concentrations were increased in both WT and eNOS-/- mice supplemented with BRJ+ (P < 0.001), whereas nitrite concentrations were increased only in eNOS-/- mice (P < 0.001). BRJ- did not alter nitrate/nitrite concentrations. SBP was lowered and UtA endothelial function was enhanced in eNOS-/- mice supplemented with either BRJ+ or BRJ-, indicating nitrate-independent effects of BRJ. Improvements in endothelial function in eNOS-/- mice were abrogated in the presence of 25 mm KCl, implicating enhanced EDH signalling in BRJ- treated animals. At GD18.5, eNOS-/- fetuses were significantly smaller than WT animals (P < 0.001), but BRJ supplementation did not affect fetal weight. BRJ may be a beneficial intervention in pregnancies associated with hypertension, endothelial dysfunction and reduced NO bioavailability. Our data showing biological effects of non-nitrate components of BRJ have implications for both interpretation of previous findings and in the design of future clinical trials.

A qualitative exploration of two risk calculators using video-recorded NHS health check consultations.

BACKGROUND: The aim of the study was to explore practitioner-patient interactions and patient responses when using QRISK®2 or JBS3 cardiovascular disease (CVD) risk calculators. Data were from video-recorded NHS Health Check (NHSHC) consultations captured as part of the UK RIsk COmmunication (RICO) study; a qualitative study of video-recorded NHSHC consultations from 12 general practices in the West Midlands, UK. Participants were those eligible for NHSHC based on national criteria (40-74 years old, no existing diagnoses for cardiovascular-related conditions, not on statins), and practitioners, who delivered the NHSHC. METHOD: NHSHCs were video-recorded. One hundred twenty-eight consultations were transcribed and analysed using deductive thematic analysis and coded using a template based around Protection Motivation Theory. RESULTS: Key themes used to frame the analysis were Cognitive Appraisal (Threat Appraisal, and Coping Appraisal), and Coping Modes (Adaptive, and Maladaptive). Analysis showed little evidence of CVD risk communication, particularly in consultations using QRISK®2. Practitioners often missed opportunities to check patient understanding and encourage risk- reducing behaviour, regardless of the risk calculator used resulting in practitioner verbal dominance. JBS3 appeared to better promote opportunities to initiate risk-factor discussion, and Heart Age and visual representation of risk were more easily understood and impactful than 10-year percentage risk. However, a lack of effective CVD risk discussion in both risk calculator groups increased the likelihood of a maladaptive coping response. CONCLUSIONS: The analysis demonstrates the importance of effective, shared practitioner-patient discussion to enable adaptive coping responses to CVD risk information, and highlights a need for effective and evidence-based practitioner training. TRIAL REGISTRATION: ISRCTN ISRCTN10443908 . Registered 7th February 2017.

A qualitative study of cardiovascular disease risk communication in NHS Health Check using different risk calculators: protocol for the RIsk COmmunication in NHS Health Check (RICO) study.

BACKGROUND: NHS Health Check is a national cardiovascular disease (CVD) risk assessment programme for 40-74 year olds in England, in which practitioners should assess and communicate CVD risk, supported by appropriate risk-management advice and goal-setting. This requires effective communication, to equip patients with knowledge and intention to act. Currently, the QRISK®2 10-year CVD risk score is most common way in which CVD risk is estimated. Newer tools, such as JBS3, allow manipulation of risk factors and can demonstrate the impact of positive actions. However, the use, and relative value, of these tools within CVD risk communication is unknown. We will explore practitioner and patient CVD risk perceptions when using QRISK®2 or JBS3, the associated advice or treatment offered by the practitioner, and patients' responses. METHODS: RIsk COmmunication in NHS Health Check (RICO) is a qualitative study with quantitative process evaluation. Twelve general practices in the West Midlands of England will be randomised to one of two groups: usual practice, in which practitioners use QRISK®2 to assess and communicate CVD risk; intervention, in which practitioners use JBS3. Twenty Health Checks per practice will be video-recorded (n = 240, 120 per group), with patients stratified by age, gender and ethnicity. Post-Health Check, video-stimulated recall (VSR) interviews will be conducted with 48 patients (n = 24 per group) and all practitioners (n = 12-18), using video excerpts to enhance participant recall/reflection. Patient medical record reviews will detect health-protective actions in the first 12-weeks following a Health Check (e.g., lifestyle referrals, statin prescription). Risk communication, patient response and intentions for health-protective behaviours in each group will be explored through thematic analysis of video-recorded Health Checks (using Protection Motivation Theory as a framework) and VSR interviews. Process evaluation will include between-group comparisons of quantitatively coded Health Check content and post-Health Check patient outcomes. Finally, 10 patients with the most positive intentions or behaviours will be selected for case study analysis (using all data sources). DISCUSSION: This study will produce novel insights about the utility of QRISK®2 and JBS3 to promote patient and practitioner understanding and perception of CVD risk and associated implications for patient intentions with respect to health-protective behaviours (and underlying mechanisms). Recommendations for practice will be developed. TRIAL REGISTRATION: ISRCTN ISRCTN10443908 . Registered 7th February 2017.

Nitrite mediated vasorelaxation in human chorionic plate vessels is enhanced by hypoxia and dependent on the NO-sGC-cGMP pathway.

Adequate perfusion of the placental vasculature is essential to meet the metabolic demands of fetal growth and development. Lacking neural control, local tissue metabolites, circulating and physical factors contribute significantly to blood flow regulation. Nitric oxide (NO) is a key regulator of fetoplacental vascular tone. Nitrite, previously considered an inert end-product of NO oxidation, has been shown to provide an important source of NO. Reduction of nitrite to NO may be particularly relevant in tissue when the oxygen-dependent NO synthase (NOS) activity is compromised, e.g. in hypoxia. The contribution of this pathway in the placenta is currently unknown. We hypothesised that nitrite vasodilates human placental blood vessels, with enhanced efficacy under hypoxia. Placentas were collected from uncomplicated pregnancies and the vasorelaxant effect of nitrite (10-6-5x10-3 M) was assessed using wire myography on isolated pre-constricted chorionic plate arteries (CPAs) and veins (CPVs) under normoxic (pO2 ∼5%) and hypoxic (pO2 ∼1%) conditions. The dependency on the NO-sGC-cGMP pathway and known nitrite reductase (NiR) activities was also investigated. Nitrite caused concentration-dependent vasorelaxation in both arteries and veins, and this effect was enhanced by hypoxia, significantly in CPVs (P < 0.01) and with a trend in CPAs (P = 0.054). Pre-incubation with NO scavengers (cPTIO and oxyhemoglobin) attenuated (P < 0.01 and P < 0.0001, respectively), and the sGC inhibitor ODQ completely abolished nitrite-mediated vasorelaxation, confirming the involvement of NO and sGC. Inhibition of potential NiR enzymes xanthine oxidoreductase, mitochondrial aldehyde dehydrogenase and mitochondrial bc1 complex did not attenuate vasorelaxation. This data suggests that nitrite may provide an important reservoir of NO bioactivity within the placenta to enhance blood flow when fetoplacental oxygenation is impaired, as occurring in pregnancy diseases such as pre-eclampsia and fetal growth restriction.

Effects of dietary nitrate supplementation, from beetroot juice, on blood pressure in hypertensive pregnant women: A randomised, double-blind, placebo-controlled feasibility trial.

Chronic hypertension in pregnancy is associated with significant adverse pregnancy outcomes, increasing the risk of pre-eclampsia, fetal growth restriction and preterm birth. Dietary nitrate, abundant in green leafy vegetables and beetroot, is reduced in vivo to nitrite and subsequently nitric oxide, and has been demonstrated to lower blood pressure, improve vascular compliance and enhance blood flow in non-pregnant humans and animals. The primary aims of this study were to determine the acceptability and efficacy of dietary nitrate supplementation, in the form of beetroot juice, to lower blood pressure in hypertensive pregnant women. In this double-blind, placebo-controlled feasibility trial, 40 pregnant women received either daily nitrate supplementation (70 mL beetroot juice, n = 20) or placebo (70 mL nitrate-depleted beetroot juice, n = 20) for 8 days. Blood pressure, cardiovascular function and uteroplacental blood flow was assessed at baseline and following acute (3 h) and prolonged (8 days) supplementation. Plasma and salivary samples were collected for analysis of nitrate and nitrite concentrations and acceptability of this dietary intervention was assessed based on questionnaire feedback. Dietary nitrate significantly increased plasma and salivary nitrate/nitrite concentrations compared with placebo juice (p < 0.001), with marked variation between women. Compared with placebo, there was no overall reduction in blood pressure in the nitrate-treated group; however there was a highly significant correlation between changes in plasma nitrite concentrations and changes in diastolic blood pressure in the nitrate-treated arm only (r = -0.6481; p = 0.0042). Beetroot juice supplementation was an acceptable dietary intervention to 97% of women. This trial confirms acceptability and potential efficacy of dietary nitrate supplementation in pregnant women. Conversion of nitrate to nitrite critically involves oral bacterial nitrate reductase activities. We speculate that differences in efficacy of nitrate supplementation relate to differences in the oral microbiome, which will be investigated in future studies.

Dietary interventions for fetal growth restriction - therapeutic potential of dietary nitrate supplementation in pregnancy.

Fetal growth restriction (FGR) affects around 5% of pregnancies and is associated with significant short- and long-term adverse outcomes. A number of factors can increase the risk of FGR, one of which is poor maternal diet. In terms of pathology, both clinically and in many experimental models of FGR, impaired uteroplacental vascular function is implicated, leading to a reduction in the delivery of oxygen and nutrients to the developing fetus. Whilst mechanisms underpinning impaired uteroplacental vascular function are not fully understood, interventions aimed at enhancing nitric oxide (NO) bioavailability remain a key area of interest in obstetric research. In addition to endogenous NO production from the amino acid l-arginine, via nitric oxide synthase (NOS) enzymes, research in recent years has established that significant NO can be derived from dietary nitrate, via the 'alternative NO pathway'. Dietary nitrate, abundant in green leafy vegetables and beetroot, can increase NO bioactivity, conferring beneficial effects on cardiovascular function and blood flow. Given the beneficial effects of dietary nitrate supplementation to date in non-pregnant humans and animals, current investigations aim to assess the therapeutic potential of this approach in pregnancy to enhance NO bioactivity, improve uteroplacental vascular function and increase fetal growth.

What influences general practitioners' use of exercise for patients with chronic knee pain? Results from a national survey.

BACKGROUND: Exercise is a recommended 'core' treatment for chronic knee pain (CKP), however it appears to be underused by general practitioners (GPs). While behavioural theories suggest that attitudes and beliefs influence behaviours, no single theory reliably predicts GPs' behaviours. A theoretical analysis framework, developed from sociocognitive theories, was used to underpin investigation of the key influences associated with GPs' use of exercise for patients with CKP, to inform future interventions to optimise GPs' use of exercise. METHODS: A cross-sectional postal questionnaire survey investigated UK GPs' reported use of exercise based on a patient case vignette. Factors influencing GPs' exercise use (behaviour) were examined using attitude statements, free-text questions and multiple response option questions related to factors within the analysis framework. Unadjusted logistic regression analyses explored the associations between GPs' attitudes/beliefs and behaviour. RESULTS: From a total sample of 5000 GPs, 835 (17%) returned a questionnaire. Most respondents (n = 729, 87%) reported that they would use exercise. Factors significantly associated with exercise use (OR (95% CI)) included GPs' beliefs about their role (belief that GPs should give information on type, duration and frequency of exercise (30.71 (5.02,188.01)), beliefs about consequences (agreement that knee problems are improved by local (3.23 (1.94,5.39)) and general exercise (2.63 (1.38,5.02))), moral norm (agreement that GPs should prescribe all patients local (3.08 (1.96,4.83)) and general exercise (2.63 (1.45,4.76))), and GP-related beliefs about capabilities (prior experience of insufficient expertise to give detailed exercise information (0.50 (0.33,0.76)). Whilst perceived time limitations were not associated with exercise use (1.00 (0.33,3.01)), GPs who disagreed that they experienced time limitations were more likely to suggest general (2.17 (1.04,4.55)), or demonstrate local (2.16 (1.06,4.42)), exercises. CONCLUSION: GPs' attitudes and beliefs are associated with their use of exercise for patients with CKP, particularly beliefs about role, responsibilities and skills in initiating exercise, and about the efficacy of exercise. Although the low response risks response bias, these results can inform future interventions to optimise GPs' behaviour. The role of GP uncertainty and influences on clinical decision-making need further exploration, thus an amended analysis framework is suggested, which should be tested in future research.