Blood pressure differences between home monitoring and daytime ambulatory values and their reproducibility in treated hypertensive stroke and TIA patients

Background: Guidelines recommend ambulatory or home blood pressure monitoring to improve hypertension diagnosis and monitoring. Both these methods are ascribed the same threshold values, but whether they produce similar results has not been established in certain patient groups. Methods: Adults with mild/moderate stroke or transient ischemic attack (N = 80) completed 2 sets of ambulatory and home blood pressure monitoring. Systolic and diastolic blood pressure values from contemporaneous measurements were compared, and the limits of agreement were assessed. Exploratory analyses for predictive factors of any difference were conducted. Results: Daytime ambulatory blood pressure values were consistently lower than home values, the mean difference in systolic blood pressure for initial ambulatory versus first home monitoring was −6.6 ± 13.5 mm Hg (P≤.001), and final ambulatory versus second home monitoring was −7.1 ± 11.0mm Hg (P≤.001). Mean diastolic blood pressure differences were −2.1 ± 8.5mm Hg (P=.03) and −2.0 ± 7.2mm Hg (P=.02). Limits of agreement for systolic blood pressure were −33.0 to 19.9mm Hg and −28.7 to 14.5mm Hg for the 2 comparisons and for DBP were −18.8 to 14.5mm Hg and −16.1 to 12.2mm Hg, respectively. The individual mean change in systolic blood pressure difference was 11.0 ± 8.3mm Hg across the 2 comparisons. No predictive factors for these differences were identified. Conclusions: Daytime ambulatory systolic and diastolic blood pressure values were significantly lower than home monitored values at both time points. Differences between the 2 methods were not reproducible for individuals. Using the same threshold value for both out-of-office measurement methods may not be appropriate in patients with cerebrovascular disease

Randomised controlled trial of a Calcium Channel or Angiotensin Converting Enzyme Inhibitor/Angiotensin Receptor Blocker Regime to Reduce Blood Pressure Variability following Ischaemic Stroke (CAARBS): a protocol for a feasibility study

Introduction Raised blood pressure (BP) is common after stroke and is associated with a poor prognosis, yet trials of BP lowering in the immediate poststroke period have not demonstrated a benefit. One possible explanation for this may be that BP variability (BPV) rather than absolute levels predicts outcome, as BPV is increased after stroke and is associated with poor outcomes. Furthermore, there is evidence of distinct antihypertensive class effects on BPV despite similar BP-lowering effects. However, whether BPV in the immediate poststroke period is a therapeutic target has not been prospectively investigated. The objectives of this trial are to assess the feasibility and safety of recruiting patients following an acute ischaemic stroke or transient ischaemic attack (TIA) to an interventional randomised controlled trial comparing the effects of two different antihypertensive drug classes on BPV. Secondary exploratory objectives are to assess if different therapeutic strategies have diverse effects on levels of BPV and if this has an impact on outcomes. Methods 150 adult patients with first-ever ischaemic stroke or TIA who require antihypertensive therapy for secondary prevention will be recruited within 7 days of the event from stroke services across three sites. After baseline assessments they will be randomly assigned to treatment with a calcium channel blocker or ACE inhibitor/angiotensin receptor blocker-based regimen and followed up for a period of three months. Ethics and dissemination Ethical and regulatory approvals have been granted. Dissemination is planned via publication in peer-reviewed medical journals and presentation at relevant conferences. Trial registration number ISRCTN10853487

Using novel methodologies to examine the impact of artificial light at night on the cortisol stress response in dispersing Atlantic salmon (Salmo salarL.) fry

Artificial light at night (ALAN) is gaining recognition as having an important anthropogenic impact on the environment, yet the behavioural and physiological impacts of this stressor are largely unknown. This dearth of information is particularly true for freshwater ecosystems, which are already heavily impacted by anthropogenic pressures. Atlantic salmon (Salmo salar L.) is a species of conservation and economic importance whose ecology and behaviour is well studied, making it an ideal model species. Recent investigations have demonstrated that salmon show disrupted behaviour in response to artificial light; however, it is not yet clear which physiological processes are behind the observed behavioural modifications. Here, two novel non-invasive sampling methods were used to examine the cortisol stress response of dispersing salmon fry under different artificial lighting intensities. Fish egg and embryos were reared under differing ALAN intensities and individual measures of stress were subsequently taken from dispersing fry using static sampling, whereas population-level measures were achieved using deployed passive samplers. Dispersing fry exposed to experimental confinement showed elevated cortisol levels, indicating the capacity to mount a stress response at this early stage in ontogenesis. However, only one of the two methods for sampling cortisol used in this study indicated that ALAN may act as a stressor to dispersing salmon fry. As such, a cortisol-mediated response to light was not strongly supported. Furthermore, the efficacy of the two non-invasive methodologies used in this study is, subject to further validation, indicative of them proving useful in future ecological studies

Can cardiovascular risk management be improved by shared care with general practice to prevent cognitive decline following stroke/TIA? A feasibility randomised controlled trial (SERVED Memory)

BACKGROUND: Cognitive impairment and dementia following cerebrovascular disease are increasingly common in the UK. One potential strategy to prevent post-stroke cognitive decline is multimodal vascular risk factor management. However, its efficacy remains uncertain and its application in vulnerable patients with incident cerebrovascular disease and early cognitive impairment has not been assessed. The primary aim of this study was to assess the feasibility of recruitment and retention of patients with early cognitive impairment post-stroke or transient ischaemic attack (TIA) to a trial of enhanced vascular risk factor management combining primary and secondary care. METHODS: In this single centre, open label trial adults with a recent stroke or TIA and mild cognitive impairment (MCI) were randomised 1:1 to a three-monthly multimodal vascular risk factor intervention jointly delivered by the trial team and General Practitioner (GP), or control (defined as usual care from the GP). Chosen risk factors were blood pressure (BP), total cholesterol, blood glucose (HbA1C) in those with diabetes, and heart rate and adequacy of anticoagulation in those with atrial fibrillation (AF). Similar patients with normal cognition were enrolled in an embedded observational cohort and also received usual care from the GP. Repeat cognitive screening was undertaken in all participants after 12 months. RESULTS: Seventy three participants were recruited to the randomised trial and 94 to the observational cohort (21.8% of those screened). From the randomised trial 35/73 (47.9%) dropped out before final follow-up. In all groups guideline based rates of risk factor control were mostly poor at baseline and did not significantly improve during follow-up. The observational cohort demonstrated greater decline in cognitive test scores at 12 months, with no difference between the randomised groups. CONCLUSIONS: Recruitment to such a study was feasible, but retention of participants was difficult and generally poor rates of risk factor control suggested insufficient application of the intervention. Consequently, successful scaling up of the trial would require protocol changes with less reliance on primary care services. Any future trial should include participants with normal cognition post-stroke as they may be at greatest risk of cognitive decline. TRIAL REGISTRATION: ISRCTN, ISRCTN42688361 . Registered 16 April 2015

Cryogenic Gellant and Fuel Formulation for Metallized Gelled Propellants: Hydrocarbons and Hydrogen with Aluminum

An experimental program to determine the viability of nanoparticulate gellant materials for gelled hydrocarbons and gelled liquid hydrogen was conducted. The gellants included alkoxides (BTMSE and BTMSH) and silica-based materials. Hexane, ethane, propane and hydrogen were gelled with the newly-formulated materials and their rheological properties were determined: shear stress versus shear rate and their attendant viscosities. Metallized hexane with aluminum particles was also rheologically characterized. The propellant and gellant formulations were selected for the very high surface area and relatively-high energy content of the gellants. These new gellants can therefore improve rocket engine specific impulse over that obtained with traditional cryogenic-fuel gellant materials silicon dioxide, frozen methane, or frozen ethane particles. Significant reductions in the total mass of the gellant were enabled in the fuels. In gelled liquid hydrogen, the total mass of gellant was reduced from 10-40 wt percent of frozen hydrocarbon particles to less that 8 wt percent with the alkoxide

Breed differences in development of anti-insulin antibodies in diabetic dogs and investigation of the role of dog leukocyte antigen (DLA) genes

Administration of insulin for treatment of diabetes mellitus in dogs can stimulate an immune response, with a proportion of animals developing anti-insulin antibodies (AIA). For an IgG antibody response to occur, this would require B cell presentation of insulin peptides by major histocompatibility complex (MHC) class II molecules, encoded by dog leukocyte antigen (DLA) genes, in order to receive T-cell help for class switching. DLA genes are highly polymorphic in the dog population and vary from breed to breed. The aim of the present study was to evaluate AIA reactivity in diabetic dogs of different breeds and to investigate whether DLA genes influence AIA status. Indirect ELISA was used to determine serological reactivity to insulin in diabetic dogs, treated with either a porcine or bovine insulin preparation. DLA haplotypes for diabetic dogs were determined by sequence-based typing of DLA-DRB1, -DQA1 and -DQB1 loci. Significantly greater insulin reactivity was seen in treated diabetic dogs (n = 942) compared with non-diabetic dogs (n = 100). Relatively few newly diagnosed diabetic dogs (3/109) were found to be AIA positive, although this provides evidence that insulin autoantibodies might be involved in the pathogenesis of the disease in some cases. Of the diabetic dogs treated with a bovine insulin preparation, 52.3% (182/348) were AIA positive, compared with 12.6% (75/594) of dogs treated with a porcine insulin preparation, suggesting that bovine insulin is more immunogenic. Breeds such as dachshund, Cairn terrier, miniature schnauzer and Tibetan terrier were more likely to develop AIA, whereas cocker spaniels were less likely to develop AIA, compared with crossbreed dogs. In diabetic dogs, DLA haplotype DRB1*0015--DQA1*006--DQB1*023 was associated with being AIA positive, whereas the haplotype DLA-DRB1*006--DQA1*005--DQB1*007 showed an association with being AIA negative. These research findings suggest that DLA genes influence AIA responses in treated diabetic dogs

Fungal diversity regulates plant-soil feedbacks in temperate grassland

Feedbacks between plants and soil microbial communities play an important role in vegetation dynamics, but the underlying mechanisms remain unresolved. Here, we show that the diversity of putative pathogenic, mycorrhizal, and saprotrophic fungi is a primary regulator of plant-soil feedbacks across a broad range of temperate grassland plant species. We show that plant species with resource-acquisitive traits, such as high shoot nitrogen concentrations and thin roots, attract diverse communities of putative fungal pathogens and specialist saprotrophs, and a lower diversity of mycorrhizal fungi, resulting in strong plant growth suppression on soil occupied by the same species. Moreover, soil properties modulate feedbacks with fertile soils, promoting antagonistic relationships between soil fungi and plants. This study advances our capacity to predict plant-soil feedbacks and vegetation dynamics by revealing fundamental links between soil properties, plant resource acquisition strategies, and the diversity of fungal guilds in soil

Explorations, Vol. 4, No. 3

Articles include: Cover: Trophy: MooseHorn, from the Trophy Series, by Caellaigh B. Desrosiers. Editorial Reflections, by Carole J. Bombard North Cascade Glacier Climate Project, by Mauri Pelto Stained Glass Molecules, by Anne P. Sherblom Lobsters Inside-Out: A Guide to the Maine Lobster Community Forestry: UMaine Cooperative Extension Service, by Nancy E. Coverstone and William D. Lilley Where Are They Now? — Robert F. LaPrade, M.D. ’81 Little Critters with a Big Job: Ciliated Protozoa and the Gulf of Maine Food Chain, by Marcia Gauvin from a paper by Charles Gregory The Innovation of Tradition: Low-Cost, Low-Input Alternatives for Maine Farmers, by Marcia Gauvin Just What IS An Animal? Preschoolers Investigate Merging Two Cultures: Our Cover Artist, by Caellaigh Bennett Derosiers Freezing and Photosynthesis, by Steven R. Dudgeon, Ian R. Davison, and Robert L. Vada

A calcium channel or angiotensin converting enzyme inhibitor/angiotensin receptor blocker regime to reduced blood pressure variability in acute ischaemic stroke (CAARBS): A feasibility trial

Background: Trials of lowering blood pressure in patients with acute ischaemic stroke not undergoing thrombolysis have not demonstrated improved outcomes with intervention. Rather than absolute levels, it may be that blood pressure variability is important. However, there are no prospective randomised trials investigating the benefit of reducing blood pressure variability in this patient group. Aims: The primary aim of this trial was to determine the feasibility of recruitment to a randomised trial investigating the effect of different antihypertensive medications on blood pressure variability. Methods: CAARBS was a multi-centre, open-label, randomised parallel group controlled feasibility trial. Adults with a first mild-moderate ischaemic stroke or transient ischaemic attack, requiring antihypertensive therapy for secondary prevention, were randomised to a calcium channel blocker or angiotensin-converting enzyme inhibitor/angiotensin receptor blocker. Blood pressure and variability were measured at baseline, three weeks, and three months. Compliance with measurements and treatment was monitored. Results: Fourteen patients were recruited to the trial (0.6% of those screened), nine of whom completed follow-up. The majority of patients screened (98.1%) were ineligible. Compliance with the intervention was good, as were measurement completion rates (88.9% or higher in all cases except ambulatory measurements). No major adverse events were recorded. Conclusions: Recruitment to the trial was difficult due to patient ineligibility, suggesting that the current protocol is unlikely to be successful if scaled for a definitive trial. However, the intervention was safe, and compliance was good, suggesting a future trial with modified eligibility criteria could be successful. Trial registration: ISRCTN10853487

Self-Monitoring and Management of Blood Pressure in Patients with Stroke or TIA: An Economic Evaluation of TEST-BP, A Randomised Controlled Trial

Abstract: Background: Prevention of secondary stroke following initial ictus is an important focus of after-stroke care. Blood pressure (BP) is a key risk factor, so usual care following stroke or transient ischaemic attack includes regular BP checks and monitoring of anti-hypertensive medication. This is traditionally carried out in primary care, but the evidence supporting self-monitoring and self-guided management of BP in the general population with hypertension is growing. Objective: Our objective was to estimate the cost effectiveness of treatment as usual (TAU) versus (1) self-monitoring of BP (S-MON) and (2) self-monitoring and guided self-management of anti-hypertensive medication (S-MAN). Methods: This was a within-trial economic evaluation of a randomised controlled trial estimating the incremental cost per 1 mmHg BP reduction and per quality-adjusted life-year (QALY) gained over a 6-month time horizon from the perspective of the UK National Health Service (NHS). Results: Data were evaluable for 140 participants. Costs per patient were £473, £853 and £1035; mean reduction in systolic BP (SBP) was 3.6, 6.7 and 6.1 mmHg, and QALYs accrued were 0.427, 0.422 and 0.423 for TAU, S-MON and S-MAN, respectively. No statistically significant differences in incremental costs or outcomes were detected. On average, S-MAN was dominated or extended dominated. The incremental cost per 1 mmHg BP reduction from S-MON versus TAU was £137. Conclusion: On average, S-MAN is an inefficient intervention. S-MON may be cost effective, depending on the willingness to pay for a 1 mmHg BP reduction, although it yielded fewer QALYs over the within-trial time horizon. Decision modelling is required to explore the longer-term costs and outcomes