201 research outputs found

    A structural and catalytic model for zinc phosphoesterases

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    A structural model for the active site of phosphoesterases, enzymes that degrade organophosphate neurotoxins, has been synthesised. The ligand 2-((2-hydroxy-3-(((2-hydroxyethyl)(pyridin-2-ylmethyl)amino)methyl)-5-methylbenzyl)(pyridin-2-ylmethyl)amino)acetic acid (H(3)L1) and two Zn(ii) complexes have been prepared and characterised as and The ligand (H(3)L1) and complex were characterised through (1)H NMR, (13)C NMR, mass spectroscopy and microanalysis. The X-ray crystal structure of revealed a tetramer of dinuclear complexes, bridged by two phosphate molecules and bifurcating acetic acid arms. Functional studies of the zinc complex with the substrate bis(4-nitrophenyl)phosphate (bNPP) determined the complex with HL1(2-) to be a competent catalyst with k(cat) = 1.26 0.06 x 10(-6) s(-1)

    Optimisation of three-dimensional lower jaw resection margin planning using a novel Black Bone magnetic resonance imaging protocol

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    Background MRI is the optimal method for sensitive detection of tumour tissue and pre-operative staging in oral cancer. When jawbone resections are necessary, the current standard of care for oral tumour surgery in our hospital is 3D virtual planning from CT data. 3D printed jawbone cutting guides are designed from the CT data. The tumour margins are difficult to visualise on CT, whereas they are clearly visible on MRI scans. The aim of this study was to change the conventional CT-based workflow by developing a method for 3D MRI-based lower jaw models. The MRI-based visualisation of the tumour aids in planning bone resection margins. Materials and findings A workflow for MRI-based 3D surgical planning with bone cutting guides was developed using a four-step approach. Key MRI parameters were defined (phase 1), followed by an application of selected Black Bone MRI sequences on healthy volunteers (phase 2). Three Black Bone MRI sequences were chosen for phase 3: standard, fat saturated, and an out of phase sequence. These protocols were validated by applying them on patients (n = 10) and comparison to corresponding CT data. The mean deviation values between the MRI-and the CT-based models were 0.63, 0.59 and 0.80 mm for the three evaluated Black Bone MRI sequences. Phase 4 entailed examination of the clinical value during surgery, using excellently fitting printed bone cutting guides designed from MRI-based lower jaw models, in two patients with oral cancer. The mean deviation of the resection planes was 2.3 mm, 3.8 mm for the fibula segments, and the mean axis deviation was the fibula segments of 1.9 E. Conclusions This study offers a method for 3D virtual resection planning and surgery using cutting guides based solely on MRI imaging. Therefore, no additional CT data are required for 3D virtual planning in oral cancer surgery

    Functional Swallowing Units (FSUs) as organs-at-risk for radiotherapy. PART 2:Advanced delineation guidelines for FSUs

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    Background and purpose: In a separate article (PART 1), a rationale and explanation of the physiology-and-anatomy-based concept of Functional Swallowing Units (FSUs) was presented. FSUs are swallowing muscles not included in the set of commonly defined swallowing organs at risk (SWOARs). They are involved in three crucial swallowing components: hyolaryngeal elevation (HLE), tongue base retraction (TBR) and tongue motion. This paper is a continuation of PART 1 and it provides detailed computed tomography (CT)-based delineation guidelines for FSUs, which presumably are also at risk of radiationinduced dysphagia. Material and methods: Following analysis of swallowing physiology and human anatomy, presented in PART 1, CT-based delineation guidelines for defined FSUs were created. Delineation was performed by the first author and revised by a panel of experts. Results and conclusions: Detailed delineation guidelines are presented for seven FSUs involved in HLE, TBR and tongue motion. The guidelines are supplemented by CT and MRI-based exemplary illustrations and complete CT/MRI-based delineation atlases (available online). This paper provides information essential to the implementation of the FSU concept in radiation practice, and supports uniform contouring, data collection and further improvement of swallowing sparing radiation-based strategies. (C) 2018 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

    Coronary revascularization treatment based on dual-source computed tomography

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    Therapy advice based on dual-source computed tomography (DSCT) in comparison with coronary angiography (CAG) was investigated and the results evaluated after 1-year follow-up. Thirty-three consecutive patients (mean age 61.9 years) underwent DSCT and CAG and were evaluated independently. In an expert reading (the “gold standard”), CAG and DSCT examinations were evaluated simultaneously by an experienced radiologist and cardiologist. Based on the presence of significant stenosis and current guidelines, therapy advice was given by all readers blinded from the results of other readings and clinical information. Patients were treated based on a multidisciplinary team evaluation including all clinical information. In comparison with the gold standard, CAG had a higher specificity (91%) and positive predictive value (PPV) (95%) compared with DSCT (82% and 91%, respectively). DSCT had a higher sensitivity (96%) and negative predictive value (NPV) (89%) compared with CAG (91% and 83%, respectively). The DSCT-based therapy advice did not lead to any patient being denied the revascularization they needed according to the multidisciplinary team evaluation. During follow-up, two patients needed additional revascularization. The high NPV for DSCT for revascularization assessment indicates that DSCT could be safely used to select patients benefiting from medical therapy only

    Functional outcome in older adults with joint pain and comorbidity: design of a prospective cohort study

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    <p>Abstract</p> <p>Background</p> <p>Joint pain is a highly prevalent condition in the older population. Only a minority of the older adults consult the general practitioner for joint pain, and during consultation joint pain is often poorly recognized and treated, especially when other co-existing chronic conditions are involved. Therefore, older adults with joint pain and comorbidity may have a higher risk of poor functional outcome and decreased quality of life (QoL), and possibly need more attention in primary care. The main purpose of the study is to explore functioning in older adults with joint pain and comorbidity, in terms of mobility, functional independence and participation and to identify possible predictors of poor functional outcome. The study will also identify predictors of decreased QoL. The results will be used to develop prediction models for the early identification of subgroups at high risk of poor functional outcome and decreased QoL. This may contribute to better targeting of treatment and to more effective health care in this population.</p> <p>Methods/Design</p> <p>The study has been designed as a prospective cohort study, with measurements at baseline and after 6, 12 and 18 months. For the recruitment of 450 patients, 25 general practices will be approached. Patients are eligible for participation if they are 65 years or older, have at least two chronic conditions and report joint pain on most days. Data will be collected using various methods (i.e. questionnaires, physical tests, patient interviews and focus groups). We will measure different aspects of functioning (e.g. mobility, functional independence and participation) and QoL. Other measurements concern possible predictors of functioning and QoL (e.g. pain, co-existing chronic conditions, markers for frailty, physical performance, psychological factors, environmental factors and individual factors). Furthermore, health care utilization, health care needs and the meaning and impact of joint pain will be investigated from an older person's perspective.</p> <p>Discussion</p> <p>In this paper, we describe the protocol of a prospective cohort study in Dutch older adults with joint pain and comorbidity and discuss the potential strengths and limitations of the study.</p

    Differences in energy balance-related behaviours in European preschool children: The ToyBox-study

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    Background: The aim of the current study was to compare levels of energy balance-related behaviours (physical activity, sedentary behaviour, and dietary behaviours (more specifically water consumption, sugar-sweetened beverage consumption and unhealthy snacking)) in four- to six-year-old preschoolers from six European countries (Belgium, Bulgaria, Germany, Greece, Poland, and Spain) within the ToyBox cross-sectional study. Methods: A sample of 4,045 preschoolers (4.77 Âą 0.43 years; 52.2% boys) had valid physical activity data (steps per day), parents of 8,117 preschoolers (4.78 Âą 0.46 years; 53.0% boys) completed a parental questionnaire with questions on sedentary behaviours (television viewing, computer use, and quiet play), and parents of 7,244 preschoolers (4.77 Âą 0.44 years; 52.0% boys) completed a food frequency questionnaire with questions on water consumption, sugar-sweetened beverage consumption and unhealthy snacking. Results: The highest levels of physical activity were found in Spain (12,669 steps/day on weekdays), while the lowest levels were found in Bulgaria and Greece (9,777 and 9,656 steps/day on weekdays, respectively). German preschoolers spent the least amount of time in television viewing (43.3 min/day on weekdays), while Greek preschoolers spent the most time in television viewing (88.5 min/day on weekdays). A considerable amount of time was spent in quiet play in all countries, with the highest levels in Poland (104.9 min/day on weekdays), and the lowest levels in Spain (60.4 min/day on weekdays). Belgian, German, and Polish preschoolers had the lowest intakes of water and the highest intakes of sugar-sweetened beverages. The intake of snacks was the highest in Belgian preschoolers (73.1 g/day) and the lowest in Greek preschoolers (53.3 g/day). Conclusions: Across six European countries, differences in preschoolers'' energy balance-related behaviours were found. Future interventions should target European preschoolers '' energy balance- related behaviours simultaneously, but should apply country-specific adaptations

    Effect and process evaluation of a kindergarten-based, family-involved cluster randomised controlled trial in six European countries on four- to six-year-old children's steps per day: The ToyBox-study

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    Background: The ToyBox-intervention is a theory- and evidence-based intervention delivered in kindergartens to improve four- to six-year-old children''s energy balance-related behaviours and prevent obesity. The current study aimed to (1) examine the effect of the ToyBox-intervention on increasing European four- to six-year-old children'' steps per day, and (2) examine if a higher process evaluation score from teachers and parents was related to a more favourable effect on steps per day. Methods: A sample of 2438 four- to six-year-old children (51.9% boys, mean age 4.75Âą0.43years) from 6 European countries (Belgium, Bulgaria, Germany, Greece, Poland and Spain) wore a motion sensor (pedometer or accelerometer) for a minimum of two weekdays and one weekend day both at baseline and follow-up to objectively measure their steps per day. Kindergarten teachers implemented the physical activity component of the ToyBox-intervention for 6 weeks in total, with a focus on (1) environmental changes in the classroom, (2) the child performing the actual behaviour and (3) classroom activities. Children''s parents received newsletters, tip cards and posters. To assess intervention effects, multilevel repeated measures analyses were conducted for the total sample and the six intervention countries separately. In addition, process evaluation questionnaires were used to calculate a total process evaluation score (with implementation and satisfaction as a part of the overall score) for teachers and parents which was then linked with the physical activity outcomes. Results: No significant intervention effects on four- to six-year-old children'' steps per weekday, steps per weekend day and steps per average day were found, both in the total sample and in the country-specific samples (all p>0.05). In general, the intervention effects on steps per day were least favourable in four- to six-year-old children with a low teachers process evaluation score and most favourable in four- to six-year-old children with a high teachers process evaluation score. No differences in intervention effects were found for a low, medium or high parents'' process evaluation score. Conclusion: The physical activity component of the ToyBox-intervention had no overall effect on four- to six-year-old children'' steps per day. However, the process evaluation scores showed that kindergarten teachers that implemented the physical activity component of the ToyBox-intervention as planned and were satisfied with the physical activity component led to favourable effects on children''s steps per day. Strategies to motivate, actively involve and engage the kindergarten teachers and parents/caregivers are needed to induce larger effects

    What are the important components of the clinical assessment of hand problems in older adults in primary care? Results of a Delphi study

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    <p>Abstract</p> <p>Background</p> <p>To identify clinical questions and assessments regarded by health care practitioners as important when assessing undifferentiated hand pain or problems in adults aged 50 years and over presenting to primary care.</p> <p>Methods</p> <p>A purposively selected panel of 26 UK-based Health Care Practitioners comprising occupational therapists, physiotherapists, rheumatologists and general practitioners, were invited to take part in a consensus study involving three postal rounds of a Delphi questionnaire with accompanying case scenarios. Participants were asked to generate questions and assessments (round 1), rate their importance (round 2), and vote on which items were most important (round 3).</p> <p>Results</p> <p>Sixteen Health Care Practitioners agreed to participate with 11 completing all three rounds. The first round of the Delphi study generated 156 questions and 143 assessments. After three rounds agreement was reached on the importance of 25 questions and 19 assessments. Questions were weighted towards current symptoms, but also included the history of previous hand problems, self-reported hand function, co-morbidity and general health. Observation and palpation of features predominated in the choice of assessment, but specific tests, grip strength, evaluation of sensation and hand function were also included.</p> <p>Conclusions</p> <p>A pool of clinical questions and assessments were generated by Health Care Practitioners, and those considered most important for assessing older adults presenting with undifferentiated hand pain and hand problems in primary care were identified. Further evaluation is required to establish the reliability and feasibility of using these questions and assessments in primary care. In particular, the relative contribution of these questions and assessments in evaluating the nature and severity of hand problems, assisting diagnosis, indicating appropriate management, and predicting future course requires further investigation.</p
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