Platelet rich Plasma in Achilles Tendon Healing 2 (PATH-2) trial: protocol for a multicentre, participant and assessor-blinded, parallel-group randomised clinical trial comparing platelet-rich plasma (PRP) injection versus placebo injection for Achilles tendon rupture

BackgroundAchilles tendon injuries give rise to substantial long-lasting morbidity and pose considerable challenges for clinicians and patients during the lengthy healing period. Current treatment strategies struggle to curb the burden of this injury on health systems and society due to lengthy rehabilitation, work absence and reinjury risk. Platelet-rich plasma (PRP) is an autologous preparation that has been shown to improve the mechanobiological properties of tendons in laboratory and animal studies. The use of PRP in musculoskeletal injuries is on the increase despite the lack of adequately powered clinical studies.Methods and designThis is a multicentre randomised controlled trial to evaluate the efficacy and mechanism of PRP in patients with acute Achilles tendon rupture (ATR). All adults with acute ATR presenting within 12 days of the injury who are to be treated non-operatively are eligible. A total of 230 consenting patients will be randomly allocated via a remote web-based service to receive PRP injection or placebo injection to the site of the injury. All participants will be blinded to the intervention and will receive standardised rehabilitation to reduce efficacy interference.Participants will be followed up with blinded assessments of muscle–tendon function, quality of life, pain and overall patient’s functional goals at 4, 7, 13, 24 weeks and 24 months post-treatment. The primary outcome is the heel-rise endurance test (HRET), which will be supervised by a blinded assessor at 24 weeks. A subgroup of 16 participants in one centre will have needle biopsy under ultrasound guidance at 6 weeks. Blood and PRP will be analysed for cell count, platelet activation and growth factor concentrations.Ethics and disseminationThe protocol has been approved by the Oxfordshire Research Ethics Committee (Oxfordshire Research Ethics Committee A, reference no 14/SC/1333). The trial will be reported in accordance with the CONSORT statement and published in peer-reviewed scientific journals.Trial registration numberISRCTN: 54992179, assigned 12 January 2015. ClinicalTrials.gov:NCT02302664, received 18 November 2014. UK Clinical Research Network Study Portfolio Database: ID 17850.</jats:sec

Habitat structure: a fundamental concept and framework for urban soil ecology

Habitat structure is defined as the composition and arrangement of physical matter at a location. Although habitat structure is the physical template underlying ecological patterns and processes, the concept is relatively unappreciated and underdeveloped in ecology. However, it provides a fundamental concept for urban ecology because human activities in urban ecosystems are often targeted toward management of habitat structure. In addition, the concept emphasizes the fine-scale, on-the-ground perspective needed in the study of urban soil ecology. To illustrate this, urban soil ecology research is summarized from the perspective of habitat structure effects. Among the key conclusions emerging from the literature review are: (1) habitat structure provides a unifying theme for multivariate research about urban soil ecology; (2) heterogeneous urban habitat structures influence soil ecological variables in different ways; (3) more research is needed to understand relationships among sociological variables, habitat structure patterns and urban soil ecology. To stimulate urban soil ecology research, a conceptual framework is presented to show the direct and indirect relationships among habitat structure and ecological variables. Because habitat structure serves as a physical link between sociocultural and ecological systems, it can be used as a focus for interdisciplinary and applied research (e.g., pest management) about the multiple, interactive effects of urbanization on the ecology of soils

Spanish medical students’ attitudes and views towards Mental Health and Psychiatry: a multicentric cross-sectional study.

Objective The aim of this study is to investigate the attitudes towards mental illness and psychiatry among fifth year Spanish medical students. Methods The study included 171 students from three medical schools located in different areas of Spain: Cádiz; UCA (n= 113), Madrid; San Pablo-CEU (n=22), and Barcelona; UAB (n=36). They responded, prior to their undergraduate medical course in psychiatry, to the AMI questionnaire to measure the attitudes towards mental illness and to Balon’s adapted questionnaire to investigate their view towards psychiatry. Results The students (93.4 %) had a positive attitude towards mental illness (AMI). Attitudes towards psychiatry were fairly positive with a few negative views, specifically regarding the role of psychiatrists (items 11 and 13) and the prestige of the specialty (item 16). There were some statistically significant differences between the three medical schools in the perception of psychiatry as a medical discipline. A better attitude towards mental illness was associated with a better view of the overall merits of psychiatry. Conclusions Findings suggest that Spanish medical students do not have a negative attitude towards mental illness and they have a good perception of psychiatry, although there are still some misconceptions about this specialty. These student’s attitudes could favor an appropriate management of patients suffering from mental illness

Platelet-rich plasma injection for adults with acute Achilles tendon rupture: the PATH-2 RCT

BACKGROUND:Achilles tendon rupture (ATR) has a long healing period, which is challenging for patients and clinicians. Platelet-rich plasma (PRP) is an autologous concentration of platelets thought to improve tendon function recovery. Although preliminary research has indicated positive effects, there is, as yet, no evidence of clinical efficacy from adequately powered robust clinical trials. OBJECTIVES:The objectives were to determine the clinical efficacy of PRP in patients with acute ATR using an objective mechanical muscle–tendon function measure and patient-reported outcome measures (PROMs), and to determine which PRP components contribute to its mechanism. DESIGN:This was a multicentre, parallel-group, participant- and outcome assessor-blinded randomised controlled trial (RCT) comparing PRP with placebo. Two embedded substudies investigated the PRP’s quality and composition and its effects on healing tendon tissues. SETTING:This trial was set in trauma and orthopaedic surgery departments in 19 NHS hospitals in England and Wales. PARTICIPANTS:Adults with acute ATR presenting within 12 days of injury to be treated non-surgically were eligible. Patients with platelet dysfunction or leg functional deficiency were excluded. INTERVENTIONS:Participants were randomised 1 : 1 to the PRP injection group or the placebo group (dry needle in the rupture gap) by central computer-based randomisation using minimisation, stratified by centre and age. MAIN OUTCOME MEASURES:The primary outcome measure was the Limb Symmetry Index (LSI) of work during the heel-rise endurance test at 24 weeks. Secondary outcomes measures, collected at 4, 7, 13 and 24 weeks, were repetitions, maximum heel-rise height, Achilles tendon Total Rupture Score (ATRS), quality of life (as measured using the Short Form questionnaire-12 items version 2), pain and participant goal attainment. Needle biopsies of the affected tendon zone were taken under ultrasound guidance at 6 weeks from 16 participants from one centre. Whole blood was analysed for cell count. PRP was analysed for cell count, platelet activation and growth factor concentration. The primary analysis was intention to treat. RESULTS:A total of 230 participants were randomised: 114 to the PRP group (103 treated) and 116 to the placebo group (all treated). One participant withdrew after randomisation but before the intervention. At 24 weeks, 201 out of 230 participants (87.4%) completed the primary outcome and 216 out of 230 participants (93.9%) completed the PROMs. The treatment groups had similar participant characteristics. At 24 weeks, there was no difference in work LSI (mean difference –3.872; 95% confidence interval –10.454 to 2.710; p = 0.231), ATRS, pain or goal attainment between PRP- and placebo-injected participants. There were no differences between the groups in any PROM at any time point or in complication rates, including re-rupture and deep-vein thrombosis. There was no correlation between work LSI and platelet activation in PRP, or erythrocyte, leucocyte or platelet counts in whole blood or PRP. Biopsies showed similar cellularity and vascularity between groups. CONCLUSIONS:This trial design and standardised PRP preparation gives the first robust RCT evidence about PRP’s role in managing ATR, which suggests that PRP offers no patient benefit. Equally robust evidence to investigate PRP application in tendon and soft tissue injuries is required. The 24-month follow-up will be completed in April 2020. TRIAL REGISTRATION:Current Controlled Trials ISRCTN54992179. FUNDING:This project was funded by the Efficacy and Mechanism Evaluation programme, a Medical Research Council and National Institute for Health Research (NIHR) partnership. The trial was supported by the NIHR Biomedical Research Centre, Oxford, and the NIHR Fellowship programme

Urinary biomarker concentrations of captan, chlormequat, chlorpyrifos and cypermethrin in UK adults and children living near agricultural land

There is limited information on the exposure to pesticides experienced by UK residents living near agricultural land. This study aimed to investigate their pesticide exposure in relation to spray events. Farmers treating crops with captan, chlormequat, chlorpyrifos or cypermethrin provided spray event information. Adults and children residing ≤100 m from sprayed fields provided first-morning void urine samples during and outwith the spray season. Selected samples (1–2 days after a spray event and at other times (background samples)) were analysed and creatinine adjusted. Generalised Linear Mixed Models were used to investigate if urinary biomarkers of these pesticides were elevated after spray events. The final data set for statistical analysis contained 1518 urine samples from 140 participants, consisting of 523 spray event and 995 background samples which were analysed for pesticide urinary biomarkers. For captan and cypermethrin, the proportion of values below the limit of detection was greater than 80%, with no difference between spray event and background samples. For chlormequat and chlorpyrifos, the geometric mean urinary biomarker concentrations following spray events were 15.4 μg/g creatinine and 2.5 μg/g creatinine, respectively, compared with 16.5 μg/g creatinine and 3.0 μg/g creatinine for background samples within the spraying season. Outwith the spraying season, concentrations for chlorpyrifos were the same as those within spraying season backgrounds, but for chlormequat, lower concentrations were observed outwith the spraying season (12.3 μg/g creatinine). Overall, we observed no evidence indicative of additional urinary pesticide biomarker excretion as a result of spray events, suggesting that sources other than local spraying are responsible for the relatively low urinary pesticide biomarkers detected in the study population

The social value of a QALY : raising the bar or barring the raise?

Background: Since the inception of the National Institute for Health and Clinical Excellence (NICE) in England, there have been questions about the empirical basis for the cost-per-QALY threshold used by NICE and whether QALYs gained by different beneficiaries of health care should be weighted equally. The Social Value of a QALY (SVQ) project, reported in this paper, was commissioned to address these two questions. The results of SVQ were released during a time of considerable debate about the NICE threshold, and authors with differing perspectives have drawn on the SVQ results to support their cases. As these discussions continue, and given the selective use of results by those involved, it is important, therefore, not only to present a summary overview of SVQ, but also for those who conducted the research to contribute to the debate as to its implications for NICE. Discussion: The issue of the threshold was addressed in two ways: first, by combining, via a set of models, the current UK Value of a Prevented Fatality (used in transport policy) with data on fatality age, life expectancy and age-related quality of life; and, second, via a survey designed to test the feasibility of combining respondents’ answers to willingness to pay and health state utility questions to arrive at values of a QALY. Modelling resulted in values of £10,000-£70,000 per QALY. Via survey research, most methods of aggregating the data resulted in values of a QALY of £18,000-£40,000, although others resulted in implausibly high values. An additional survey, addressing the issue of weighting QALYs, used two methods, one indicating that QALYs should not be weighted and the other that greater weight could be given to QALYs gained by some groups. Summary: Although we conducted only a feasibility study and a modelling exercise, neither present compelling evidence for moving the NICE threshold up or down. Some preliminary evidence would indicate it could be moved up for some types of QALY and down for others. While many members of the public appear to be open to the possibility of using somewhat different QALY weights for different groups of beneficiaries, we do not yet have any secure evidence base for introducing such a system

Offspring sex ratio and gonadal irradiation in the British Childhood Cancer Survivor Study

We investigated offspring sex ratio among 6232 offspring born to 3218 survivors of childhood cancer in relation to therapeutic irradiation, and pooled our data with those from two other large-scale studies giving a total of 9685 offspring. Exposure to high-dose gonadal irradiation was not associated with a significant alteration in offspring sex ratio compared to low doses (men: P=0.58, women: P=0.66). There was also no evidence that the ratio varied with time since cancer diagnosis when comparing survivors treated with radiotherapy vs those without (men: P=0.51; women: P=0.46). This, the largest study to date, finds no evidence that exposure to radiation affects the offspring sex ratio among survivors of childhood cancer

Toward Human-Carnivore Coexistence: Understanding Tolerance for Tigers in Bangladesh

Fostering local community tolerance for endangered carnivores, such as tigers (Panthera tigris), is a core component of many conservation strategies. Identification of antecedents of tolerance will facilitate the development of effective tolerance-building conservation action and secure local community support for, and involvement in, conservation initiatives. We use a stated preference approach for measuring tolerance, based on the ‘Wildlife Stakeholder Acceptance Capacity’ concept, to explore villagers’ tolerance levels for tigers in the Bangladesh Sundarbans, an area where, at the time of the research, human-tiger conflict was severe. We apply structural equation modeling to test an a priori defined theoretical model of tolerance and identify the experiential and psychological basis of tolerance in this community. Our results indicate that beliefs about tigers and about the perceived current tiger population trend are predictors of tolerance for tigers. Positive beliefs about tigers and a belief that the tiger population is not currently increasing are both associated with greater stated tolerance for the species. Contrary to commonly-held notions, negative experiences with tigers do not directly affect tolerance levels; instead, their effect is mediated by villagers’ beliefs about tigers and risk perceptions concerning human-tiger conflict incidents. These findings highlight a need to explore and understand the socio-psychological factors that encourage tolerance towards endangered species. Our research also demonstrates the applicability of this approach to tolerance research to a wide range of socio-economic and cultural contexts and reveals its capacity to enhance carnivore conservation efforts worldwide

Cell-scale degradation of peritumoural extracellular matrix fibre network and its role within tissue-scale cancer invasion

Local cancer invasion of tissue is a complex, multiscale process which plays an essential role in tumour progression. Occurring over many different temporal and spatial scales, the first stage of invasion is the secretion of matrix degrading enzymes (MDEs) by the cancer cells that consequently degrade the surrounding extracellular matrix (ECM). This process is vital for creating space in which the cancer cells can progress and it is driven by the activities of specific matrix metalloproteinases (MMPs). In this paper, we consider the key role of two MMPs by developing further the novel two-part multiscale model introduced in [33] to better relate at micro-scale the two micro-scale activities that were considered there, namely, the micro-dynamics concerning the continuous rearrangement of the naturally oriented ECM fibres within the bulk of the tumour and MDEs proteolytic micro-dynamics that take place in an appropriate cell-scale neighbourhood of the tumour boundary. Focussing primarily on the activities of the membrane-tethered MT1-MMP and the soluble MMP-2 with the fibrous ECM phase, in this work we investigate the MT1-MMP/MMP-2 cascade and its overall effect on tumour progression. To that end, we will propose a new multiscale modelling framework by considering the degradation of the ECM fibres not only to take place at macro-scale in the bulk of the tumour but also explicitly in the micro-scale neighbourhood of the tumour interface as a consequence of the interactions with molecular fluxes of MDEs that exercise their spatial dynamics at the invasive edge of the tumour