Physiological experimentations with the crayfish hindgut.

Abstract The purpose of the report is to describe dissection techniques for preparing the crayfish hindgut and to demonstrate how to make physiological recordings with a force transducer to monitor the strength of contraction. In addition, we demonstrate how to visually monitor peristaltic activity, which can be used as a bioassay for various peptides, biogenic amines and neurotransmitters. This preparation is amenable to student laboratories in physiology and for demonstrating pharmacological concepts to students. This preparation has been in use for over 100 years, and it still offers much as a model for investigating the generation and regulation of peristaltic rhythms and for describing the mechanisms underlying their modulation. The pharmacological assays and receptor sub-typing that were started over 50 years ago on the hindgut still contribute to research today. This robust preparation is well suited to training students in physiology and pharmacology. Protoco

Physiological experimentations with the crayfish hindgut.

Abstract The purpose of the report is to describe dissection techniques for preparing the crayfish hindgut and to demonstrate how to make physiological recordings with a force transducer to monitor the strength of contraction. In addition, we demonstrate how to visually monitor peristaltic activity, which can be used as a bioassay for various peptides, biogenic amines and neurotransmitters. This preparation is amenable to student laboratories in physiology and for demonstrating pharmacological concepts to students. This preparation has been in use for over 100 years, and it still offers much as a model for investigating the generation and regulation of peristaltic rhythms and for describing the mechanisms underlying their modulation. The pharmacological assays and receptor sub-typing that were started over 50 years ago on the hindgut still contribute to research today. This robust preparation is well suited to training students in physiology and pharmacology. Protoco

Pressure Relieving Support Surfaces for Pressure Ulcer Prevention (PRESSURE 2): Clinical and Health Economic Results of a Randomised Controlled Trial

Background Pressure ulcers (PUs) are complications of serious acute/chronic illness. Specialist mattresses used for prevention lack high quality effectiveness evidence. We aimed to compare clinical and cost effectiveness of 2 mattress types. Methods Multicentre, Phase III, open, prospective, parallel group, randomised controlled trial in 42 UK secondary/community in-patient facilities. 2029 high risk (acutely ill, bedfast/chairfast and/or Category 1 PU/pain at PU site) adult in-patients were randomised (1:1, allocation concealment, minimisation with random element) factors including: centre, PU status, facility and consent type. Interventions were alternating pressure mattresses (APMs) or high specification foam (HSF) for maximum treatment phase 60 days. Primary outcome was time to development of new PU Category ≥ 2 from randomisation to 30 day post-treatment follow-up in intention-to treat population. Trial registration: ISRCTN 01151335. Findings Between August 2013 and November 2016, we randomised 2029 patients (1016 APMs: 1013 HSF) who developed 160(7.9%) PUs. There was insufficient evidence of a difference between groups for time to new PU Category ≥ 2 Fine and Gray Model Hazard Ratio HR = 0.76, 95%CI0.56–1.04); exact P = 0.0890; absolute difference 2%). There was a statistically significant difference in the treatment phase time to event sensitivity analysis, Fine and Gray model HR = 0.66, 95%CI, 0.46–0.93; exact P = 0.0176); 2.6% absolute difference). Economic analyses indicate that APM are cost-effective. There were no safety concerns. Interpretation In high risk (acutely ill, bedfast/chairfast/Category 1 PU/ pain on a PU site) in-patients, we found insufficient evidence of a difference in time to PU development at 30-day final follow-up, which may be related to a low event rate affecting trial power. APMs conferred a small treatment phase benefit. Patient preference, low PU incidence and small group differences suggests the need for improved targeting of APMs with decision making informed by patient preference/comfort/rehabilitation needs and the presence of potentially modifiable risk factors such as being completely immobile, nutritional deficits, lacking capacity and/or altered skin/Category1 PU

Pressure Relieving Support Surfaces: a Randomised Evaluation 2 (PRESSURE 2): using photography for blinded central endpoint review

Background PRESSURE 2 is a randomised evaluation of the clinical and cost-effectiveness of two types of mattress for the prevention of pressure ulcers (PUs). The primary clinical endpoint was time to development of a category ≥2 PU. The current ‘gold standard’ for PU identification is expert clinical assessment. Due to the mattress appearance, a blinded assessment of the endpoint is not possible. This poses a risk to the internal validity of the study. A possible approach is to use photographs of skin sites, with central blinded review. However, there are practical and scientific concerns including patients’ consent to photographs, burden of data collection, photograph quality, data completeness and comparison of photographs to the current ‘gold standard’. This paper reports the findings of the PRESSURE 2 photographic validation sub-study. Method Where consent was obtained, photographs were taken of all category ≥2 PUs on the first presentation to assess over-reporting, and for the assessment of under-reporting, a random sample of 10% patients had an assessment by an independent clinical assessor who also photographed two skin sites. The staff were trained in taking and transferring photographs using standardised procedures and equipment. A card included in the photograph recorded participant details and a ‘greyscale’ for correction of white balance during processing. Three blinded reviewers assessed the photographs and rated how confident they were in their assessment. Results The trial recruited 2029 patients; 85% consented to photography, and 532 photographs were received and used in the blinded central review. The level of confidence varied by skin classification with more confidence observed when the skin was assessed as being less severe than a category ≥2 PU. Overall, there was a very good reliability compared to the gold standard expert clinical assessment (87.8%, kappa 0.82). Conclusion Study findings have usefully informed the scientific and practical issues of blinded assessment of PU status to reducing the risk of bias in medical device trials. The reliability of central blinded expert photography was found to be ‘very good’ (PABAK). Photographs have been found to be an acceptable method of data validation for participants. Methods to improve the quality of photographs would increase the confidence in the assessments. Trial registration ISRCTN Registry ISRCTN01151335. Registered on 19 April 201

006 Comparison of alitretinoin vs. psoralen plus ultraviolet A as first-line treatments for chronic severe hand eczema: results from the ALPHA trial

Severe chronic hand eczema resistant to topical corticosteroid treatment is an important cause of morbidity and occupational disability. There is uncertainty regarding the best treatment approach and currently no treatment pathway is generally accepted by UK dermatologists. The primary aim of the ALPHA trial was to compare alitretinoin and immersion psoralen plus ultraviolet A (PUVA) as a first-line therapy in terms of disease activity at 12 weeks after the planned start of treatment. We conducted a prospective, multicentre, open-label, two-arm parallel group, adaptive randomized controlled trial. The natural logarithm of the Hand Eczema Severity Index (HECSI) + 1 at 12 weeks after the planned start of treatment was chosen as the primary endpoint so the relative effect of treatment could be estimated. In total, 514 participants were required to detect a fold change of 1.3 (5% two-sided significance level, 80% power, 20% attrition). Participants were randomized 1 : 1 by minimization to alitretinoin or immersion PUVA for 12–24 weeks. The intention-to-treat population consisted of 441 participants: 220 (49.9%) allocated to alitretinoin and 221 (50.1%) to immersion PUVA. In total, 212 (96.4%) alitretinoin participants and 196 (88.7%) immersion PUVA participants received at least one dose. There was a statistically significant benefit of alitretinoin compared with immersion PUVA at 12 weeks, with an estimated fold change of 0.66 [95% confidence interval (CI) 0.52–0.82; P 7 days during first 12 weeks). Thus, twice-weekly attendance for PUVA was not received by most participants. However, this represents standard of care with ALPHA run as a pragmatic trial using standard-of-care settings for the interventions. A further limitation was that assessment of long-term effects of randomized treatments was complicated by permitted use of second-line treatments after the treatment phase; therefore, trial conclusions are for randomized treatments as first-line therapies. We conclude that, as a first-line therapy, patients on alitretinoin showed more rapid improvement and superiority than those treated with immersion PUVA at week 12, but this difference was not observed at later time points. Future studies will need to further address the long-term benefits of treatments given and complex treatment pathways