Modelling relationships between lichen bioindicators, air quality and climate on a national scale : results from the UK OPAL air survey

Air pollution has many negative effects on the natural environment, from changes in plant growth patterns to loss of ecosystem function. This study uses citizen science to investigate national-scale patterns in the distribution and abundance of selected lichen species on tree trunks and branches, and to relate these to air pollution and climate. Volunteers collected data for nine lichen indicators on 19,334 deciduous trees. Submitted data provided information on species-level patterns, and were used to derive composite lichen indices. Multiple linear regression and ANCOVA were used to model the relationships between lichen response variables on Quercus spp. and pollution, climate and location. The study demonstrated significant relationships between patterns in indicator lichens and levels of N- and S-containing pollutants on trunks and twigs. The derived lichen indices show great potential as a tool to provide information on local, site-specific levels of air quality

Does the level of encouragement affect 6-minute walk test performance in patients with intermittent claudication? A protocol for a randomised multicentre controlled trial

Plain English Summary Why we are undertaking the research: Peripheral artery disease is a common problem where the blood vessels in the leg are narrowed by fatty build-ups. These fatty deposits may restrict blood flow which causes pain during exercise and limits how far people can walk. To assess a patient’s maximal walking distance, clinicians may use a 6-minute walk test whereby patients are asked to walk as far as possible in six minutes. Currently, encouragement is recommended during the test to ensure the patient walks as far as possible. However, the optimal frequency of this encouragement is still debated and may prove an important factor to guarantee the patient performs to the best of their ability. What we aim to do: We plan to run an investigation to assess whether the frequency of encouragement delivered by an exercise professional affects how far a patient can walk during a 6-minute walk test. People with peripheral artery disease will be asked to enrol in a 6-minute walk test every week for six weeks. During each of their six tests they will receive standardised encouragement at either 1-minute or 2-minute intervals. Following all the tests, the two groups will have their average maximal walking distances compared. At the end of the study we hope to gain an insight into how often standardised encouragement should be delivered during a 6- minute walk test. We also hope to be able to inform future guidelines of the best way to conduct this highly utilised test in people with peripheral artery disease

Effects of exercise prescribed at different levels of claudication pain on walking performance in patients with intermittent claudication: a protocol for a randomised controlled trial

Peripheral artery disease affects over 236 million people globally and the classic symptom is intermittent claudication (IC) which is associated with reduction in physical activity. The evidence that supervised exercise programmes (SEPs) improve pain-free and maximal walking distance is irrefutable. However, adherence rates are low with exercise-related pain cited as a contributing factor. National and international guidelines recommend exercising at a moderate to maximal level of claudication pain to improve walking ability; however, exercising pain-free or at mild claudication pain has been shown to achieve this outcome. There is limited evidence that compares the relative effects of exercise prescribed at different levels of claudication pain. The objective of this study is to directly compare the effects of exercise prescribed at three different levels of claudication pain on walking performance. This study will be a single-centre randomised controlled trial. Based on an power calculation, 51 patients with IC will be allocated to 24 weeks of twice-weekly pain-free (PF), moderate pain (MOD-P) or maximal pain (MAX-P) exercise. The PF group will cease exercise at the onset of claudication (1 on the 0-4 IC rating scale), the MOD-P group will stop once moderate pain is reached (2 on the rating scale) and the MAX-P group will stop once maximal pain is reached (4 on the rating scale). Outcome measures will be assessed at baseline, 12 and 24 weeks adopting an analysis of covariance (ANCOVA) to compare MWD across three time points. The primary outcome for the trial will be change in maximal treadmill walking distance at 12 and 24 weeks. Trial registration number: NCT04370327

Quality of stepped-wedge trial reporting can be reliably assessed using an updated CONSORT: crowd-sourcing systematic review

OBJECTIVES: The Consolidated Standards of Reporting Trials extension for the stepped-wedge cluster randomized trial (SW-CRT) is a recently published reporting guideline for SW-CRTs. We assess the quality of reporting of a recent sample of SW-CRTs. STUDY DESIGN AND SETTING: Quality of reporting was asssessed according to the 26 items in the new guideline using a novel crowd sourcing methodology conducted independently and in duplicate, with random assignment, by 50 reviewers. We assessed reliability of the quality assessments, proposing this as a novel way to assess robustness of items in reporting guidelines. RESULTS: Several items were well reported. Some items were very poorly reported, including several items that have unique requirements for the SW-CRT, such as the rationale for use of the design, description of the design, identification and recruitment of participants within clusters, and concealment of cluster allocation (not reported in more than 50% of the reports). Agreement across items was moderate (median percentage agreement was 76% [IQR 64 to 86]). Agreement was low for several items including the description of the trial design and why trial ended or stopped for example. CONCLUSIONS: When reporting SW-CRTs, authors should pay particular attention to ensure clear reporting on the exact format of the design with justification, as well as how clusters and individuals were identified for inclusion in the study, and whether this was done before or after randomization of the clusters, which are crucial for risk of bias assessments. Some items, including why the trial ended, might either not be relevant to SW-CRTs or might be unclearly described in the statement

The biology of the combretastatins as tumour vascular targeting agents

The tumour vasculature is an attractive target for therapy. Combretastatin A-4 (CA-4) and A-1 (CA-1) are tubulin binding agents, structurally related to colchicine, which induce vascular-mediated tumour necrosis in animal models. CA-1 and CA-4 were isolated from the African bush willow, Combretum caffrum, and several synthetic analogues are also now available, such as the Aventis Pharma compound, AVE8062. More soluble, phosphated, forms of CA-4 (CA-4-P) and CA-1 (CA-1-P) are commonly used for in vitro and in vivo studies. These are cleaved to the natural forms by endogenous phosphatases and are taken up into cells. The lead compound, CA-4-P, is currently in clinical trial as a tumour vascular targeting agent. In animal models, CA-4-P causes a prolonged and extensive shut-down of blood flow in established tumour blood vessels, with much less effect in normal tissues. This paper reviews the current understanding of the mechanism of action of the combretastatins and their therapeutic potential