Small vessels, dementia and chronic diseases - molecular mechanisms and pathophysiology.

Cerebral small vessel disease (SVD) is a major contributor to stroke, cognitive impairment and dementia with limited therapeutic interventions. There is a critical need to provide mechanistic insight and improve translation between pre-clinical research and the clinic. A 2-day workshop was held which brought together experts from several disciplines in cerebrovascular disease, dementia and cardiovascular biology, to highlight current advances in these fields, explore synergies and scope for development. These proceedings provide a summary of key talks at the workshop with a particular focus on animal models of cerebral vascular disease and dementia, mechanisms and approaches to improve translation. The outcomes of discussion groups on related themes to identify the gaps in knowledge and requirements to advance knowledge are summarized.

Examining urea flux across the intestine of the spiny dogfish, Squalus acanthias.

Recent examination of urea flux in the intestine of the spiny dogfish shark, Squalus acanthias, has shown that feeding significantly enhances urea uptake across the intestine, and this was significantly inhibited following mucosal addition of phloretin. The present study examined potential mechanisms of urea uptake across the dogfish intestine in starved and fed dogfish. Unidirectional flux chambers were used to examine the kinetics of urea uptake, and to determine the influence of sodium, ouabain, competitive urea analogues, and phloretin on urea uptake across the gut of fed dogfish. Intestinal epithelial preparations from starved and fed dogfish were mounted in Ussing chambers to examine the effect of phloretin on bidirectional solute transport across the intestine. In the unidirectional studies, the maximum uptake rate of urea was found to be 35.3±6.9 µmol.cm(-2).h(-1) and Km was found to be 291.8±9.6 mM in fed fish, and there was a mild inhibition of urea uptake following mucosal addition of competitive agonists. Addition of phloretin, Na-free Ringers and ouabain to the mucosal side of intestinal epithelia also led to a significant reduction in urea uptake in fed fish. In the Ussing chamber studies there was a net influx of urea in fed fish and a small insignificant efflux in starved fish. Addition of phloretin blocked urea uptake in fed fish when added to the mucosal side. Furthermore, phloretin had no effect on ion transport across the intestinal epithelia with the exception of the divalent cations, magnesium and calcium.

The STAR trial protocol: a randomised multi-stage phase II/III study of Sunitinib comparing temporary cessation with allowing continuation, at the time of maximal radiological response, in the first-line treatment of locally advanced/metastatic renal cancer.

BACKGROUND: Over recent years a number of novel therapies have shown promise in advanced renal cell carcinoma (RCC). Internationally the standard of care of first-line therapy is sunitinib™, after a clear survival benefit was demonstrated over interferon-α. Convention dictates that sunitinib is continued until evidence of disease progression, assuming tolerability, although there is no evidence that this approach is superior to intermittent periods of treatment. The purpose of the STAR trial is to compare the standard treatment strategy (conventional continuation strategy, CCS) with a novel drug free interval strategy (DFIS) which includes planned treatment breaks. METHODS/DESIGN: The STAR trial is an NIHR HTA-funded UK pragmatic randomised phase II/III clinical trial in the first-line treatment of advanced RCC. Participants will be randomised (1:1) to either a sunitinib CCS or a DFIS. The overall aim of the trial is to determine whether a DFIS is non-inferior, in terms of 2-year overall survival (OS) and quality adjusted life years (QALY) (averaged over treatment and follow up), compared to a CCS. The QALY primary endpoint was selected to assess whether any detriment in terms of OS could be balanced with improvements in quality of life (QoL). This is a complex trial with a number of design challenges, and to address these issues a feasibility stage is incorporated into the trial design. Predetermined recruitment (stage A) and efficacy (stage B) intermediary endpoints must be met to allow continuation to the overall phase III trial (stage C). An integral qualitative patient preference and understanding study will occur alongside the feasibility stage to investigate patients' feelings regarding participation or non-participation in the trial. DISCUSSION: The optimal duration of continuing sunitinib in advanced RCC is unknown. Novel targeted therapies do not always have the same constraints to treatment duration as standard chemotherapeutic agents and currently there are no randomised data comparing different treatment durations. Incorporating planned treatment breaks has the potential to improve QoL and cost effectiveness, hopefully without significant detriment on OS, as has been demonstrated in other cancer types with other treatments. TRIAL REGISTRATION: Controlled-trials.com ISRCTN 06473203.

Differential gene expression of soluble CD8+ T-cell mediated suppression of HIV replication in three older children.

Suppression of human immunodeficiency virus (HIV) replication by CD8+ T-cells (CD8 suppression) contributes to survival in adults and children <1 year. Soluble CD8 suppression can also be seen in some older children with AIDS. The factor responsible, CD8-derived antiviral factor (CAF), acts at the level of HIV RNA transcription. Differential gene expression techniques have been used to define the gene(s) mediating this phenomenon in adults. Recently, CAF has been linked to exosomes secreted by CD8+ T-cells. To compare the gene expression profiles from pediatric patients with each other, with those reported in 2 previous studies in adults and in those reportedly related to exosomes, we used differential gene expression to study three older children with HIV infection, one who did demonstrate soluble CD-8 suppression and two who did not. Eighteen differentially expressed genes were also seen in one adult study (P = 0.002, χ(2) test), and 38 such genes (P < 0.0001, χ(2) test) in a second adult study. In addition, two exosome components and some RNA's related to exosomal proteins were also differentially expressed. In children with HIV infection, we found significant differentially expressed genes that correlated to those previously reported in two studies in adults. Our data also lends some support to the recent identification of CAF with exosomes secreted by CD8+ T-cells.

NICE's Discounting Review: Clear Thinking on Rational Revision Meets Obstacle of Industrial Interests.

The National Institute of Health and Care Excellence (NICE) recently published a review of discounting practice and theory as part of a consultation on its current methods guidelines. The review examines the case for revision or retention of current methods. The changes considered include eliminating favourable rates in certain special cases and the reduction of the base-case rate for costs and health effects from 3.5 to 1.5%. The review also notes the potential need to reduce the cost-effectiveness threshold to accommodate a discount rate reduction, explaining that an agreement between the UK government and the pharmaceutical industry proscribes changing NICE's threshold range until the end of 2023. We believe NICE should be commended for a useful overview of the existing literature and relevant issues. We firmly endorse NICE's view that favourable discount rates are not a good way to apply a preference for certain interventions. Similarly, we support the option of reducing the discount rate to 1.5%, which better accords with real government borrowing costs. We suggest further work to clarify the appropriate theoretical basis for the NICE's social discount rate and the sensitivity of the threshold to changes in discounting. The prospects of a necessary discount rate reduction appear to depend on whether a threshold reduction can be achieved within NICE's current range or if the range itself must be revised downwards. NICE has usefully informed the debate around discount rates. Ultimately, the path to a methodologically consistent and evidence-based revision of discounting depends on whether NICE needs to adjust the threshold too and if it is free to do so.

A novel preference-informed complementary trial (PICT) design for clinical trial research influenced by strong patient preferences.

BACKGROUND: Patients and their families often have preferences for medical care that relate to wider considerations beyond the clinical effectiveness of the proposed interventions. Traditionally, these preferences have not been adequately considered in research. Research questions where patients and families have strong preferences may not be appropriate for traditional randomized controlled trials (RCTs) due to threats to internal and external validity, as there may be high levels of drop-out and non-adherence or recruitment of a sample that is not representative of the treatment population. Several preference-informed designs have been developed to address problems with traditional RCTs, but these designs have their own limitations and may not be suitable for many research questions where strong preferences and opinions are present. METHODS: In this paper, we propose a novel and innovative preference-informed complementary trial (PICT) design which addresses key weaknesses with both traditional RCTs and available preference-informed designs. In the PICT design, complementary trials would be operated within a single study, and patients and/or families would be given the opportunity to choose between a trial with all treatment options available and a trial with treatment options that exclude the option which is subject to strong preferences. This approach would allow those with strong preferences to take part in research and would improve external validity through recruiting more representative populations and internal validity. Here we discuss the strengths and limitations of the PICT design and considerations for analysis and present a motivating example for the design based on the use of opioids for pain management for children with musculoskeletal injuries. CONCLUSIONS: PICTs provide a novel and innovative design for clinical trials with more than two arms, which can address problems with existing preference-informed trial designs and enhance the ability of researchers to reflect shared decision-making in research as well as improving the validity of trials of topics with strong preferences.

UK consensus on pre-clinical vascular cognitive impairment functional outcomes assessment: Questionnaire and workshop proceedings.

Assessment of outcome in preclinical studies of vascular cognitive impairment (VCI) is heterogenous. Through an ARUK Scottish Network supported questionnaire and workshop (mostly UK-based researchers), we aimed to determine underlying variability and what could be implemented to overcome identified challenges. Twelve UK VCI research centres were identified and invited to complete a questionnaire and attend a one-day workshop. Questionnaire responses demonstrated agreement that outcome assessments in VCI preclinical research vary by group and even those common across groups, may be performed differently. From the workshop, six themes were discussed: issues with preclinical models, reasons for choosing functional assessments, issues in interpretation of functional assessments, describing and reporting functional outcome assessments, sharing resources and expertise, and standardization of outcomes. Eight consensus points emerged demonstrating broadly that the chosen assessment should reflect the deficit being measured, and therefore that one assessment does not suit all models; guidance/standardisation on recording VCI outcome reporting is needed and that uniformity would be aided by a platform to share expertise, material, protocols and procedures thus reducing heterogeneity and so increasing potential for collaboration, comparison and replication. As a result of the workshop, UK wide consensus statements were agreed and future priorities for preclinical research identified.

Global evidence of gender inequity in academic health research: a living scoping review protocol.

OBJECTIVE: The objective of this review is to describe the global evidence of gender inequity among individuals with appointments at academic institutions that conduct health research, and examine how gender intersects with other social identities to influence outcomes. INTRODUCTION: The gender demographics of universities have shifted, yet the characteristics of those who lead academic health research institutions have not reflected this change. Synthesized evidence will guide decision-making and policy development to support the progress of gender and other under-represented social identities in academia. INCLUSION CRITERIA: This review will consider any quantitative, qualitative, or mixed methods primary research that reports outcome data related to gender equity and other social identities among individuals affiliated with academic or research institutions that conduct health research, originating from any country. METHODS: The JBI Manual for Evidence Synthesis and the Cochrane Collaboration's guidance on living reviews will inform the review methods. Information sources will include electronic databases, unpublished literature sources, reference scanning of relevant systematic reviews, and sources provided by experts on the research team. Searches will be run regularly to monitor the development of new literature and determine when the review will be updated. Study selection and data extraction will be conducted by two reviewers working independently, and all discrepancies will be resolved by discussion or a third reviewer. Data synthesis will summarize information using descriptive frequencies and simple thematic analysis. Results will be reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension to scoping reviews. REGISTRATION: Open Science Framework: https://osf.io/8wk7e/.

Patients Treated for Hyperthyroidism Are at Increased Risk of Becoming Obese: Findings from a Large Prospective Secondary Care Cohort.

Background: The most commonly reported symptom of hyperthyroidism is weight loss; successful treatment increases weight. Weight gain faced by patients with hyperthyroidism is widely considered a simple reaccumulation of premorbid weight, whereas many patients feel there is a significant weight "overshoot" attributable to the treatment. We aimed to establish if weight gain seen following treatment for hyperthyroidism represents replenishment of premorbid weight or "overshoot" beyond expected regain and, if there is excessive weight gain, whether this is associated with the applied treatment modality. Methods: We calculated the risk of becoming obese (body mass index [BMI] >30 kg/m2) following treatment for hyperthyroidism by comparing BMI of 1373 patients with overt hyperthyroidism seen in a secondary care setting with the age- and sex-matched background population (Health Survey for England, 2007-2009). Next, we investigated the effect of treatment with an antithyroid drug (ATD) alone in regard to ATD with radioactive iodine (131I) therapy. We modeled the longitudinal weight data in relation to the treatment pathway to thyroid function and the need for long-term thyroxine replacement. Results: During treatment of hyperthyroidism, men gained 8.0 kg (standard deviation ±7.5) and women 5.5 kg (±6.8). At discharge, there was a significantly increased risk of obesity in male (odds ratio = 1.7 [95% confidence interval 1.3-2.2], p < 0.001) and female (1.3, 1.2-1.5, p < 0.001) patients with hyperthyroidism compared with the background population. Treatment with 131I was associated with additional weight gain (0.6 kg, 0.4-0.8, p < 0.001), compared with ATD treatment alone. More weight gain was seen if serum thyrotropin (TSH) was markedly increased (TSH >10 mIU/L; 0.5 kg, 0.3-0.7, p < 0.001) or free thyroxine (fT4) was reduced (fT4 ≤ 10 pmol/L (0.8 ng/dL); 0.3 kg, 0.1-0.4, p < 0.001) during follow-up. Initiation of levothyroxine was associated with further weight gain (0.4 kg, 0.2-0.6, p < 0.001) and the predicted excess weight gain in 131I-induced hypothyroidism was 1.8 kg. Conclusions: Treatment for hyperthyroidism is associated with significant risks of becoming obese. 131I treatment and subsequent development of hypothyroidism were associated with small but significant amounts of excess weight gain compared with ATD alone. We advocate that the discussion over the weight "overshoot" risk forms part of the individualized treatment decision-making process.

Preclinical Validation of the Therapeutic Potential of Glasgow Oxygen Level Dependent (GOLD) Technology: a Theranostic for Acute Stroke.

In acute stroke patients, penumbral tissue is non-functioning but potentially salvageable within a time window of variable duration and represents target tissue for rescue. Reperfusion by thrombolysis and/or thrombectomy can rescue penumbra and improve stroke outcomes, but these treatments are currently available to a minority of patients. In addition to the utility of Glasgow Oxygen Level Dependent (GOLD) as an MRI contrast capable of detecting penumbra, its constituent perfluorocarbon (PFC) oxygen carrier, combined with normobaric hyperoxia, also represents a potential acute stroke treatment through improved oxygen delivery to penumbra. Preclinical studies were designed to test the efficacy of an intravenous oxygen carrier, the perfluorocarbon emulsion Oxycyte® (O-PFC), combined with normobaric hyperoxia (50% O2) in both in vitro (neuronal cell culture) and in vivo rat models of ischaemic stroke. Outcome was assessed through the quantification of lipid peroxidation and oxidative stress levels, mortality, infarct volume, neurological scoring and sensorimotor tests of functional outcome in two in vivo models of stroke. Additionally, we investigated evidence for any positive or negative interactions with the thrombolytic recombinant tissue plasminogen activator (rt-PA) following embolus-induced stroke in rats. Treatment with intravenous O-PFC + normobaric hyperoxia (50% O2) provided evidence of reduced infarct size and improved functional recovery. It did not exacerbate oxidative stress and showed no adverse interactions with rt-PA. The positive results and lack of adverse effects support human trials of O-PFC + 50% O2 normobaric hyperoxia as a potential therapeutic approach. Combined with the diagnostic data presented in the preceding paper, O-PFC and normobaric hyperoxia is a potential theranostic for acute ischaemic stroke.