65 research outputs found

    2H NMR evidence for dynamic disorder in human skin induced by the penetration enhancer azone

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    Penetration enhancers mediate trans-dermal drug delivery. The penetration enhancer dodecyl-azacycloheptanone (Azone(R)) was characterized in situ with H-2 NMR on human stratum corneum treated with either uniformly deuterated Azone(R) or penetration enhancer with only the entire chain deuterated, in both cases in propylene glycol. The H-2 NMR spectrum at ambient temperature constitutes a single narrow line only 180 Hz wide. This contrasts with the complex lineshapes 1-25 kHz wide commonly observed for methylene deuterons of lipids in a bilayer gel phase, Hence there is no evidence for differences in orientational behaviour between different deuterons at ambient temperature. The narrow line translates into a low overall order parameter S-CD Solid state NMR/Biophysical Organic Chemistr

    Baseline fat fraction is a strong predictor of disease progression in Becker muscular dystrophy

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    In Becker muscular dystrophy (BMD), muscle weakness progresses relatively slowly, with a highly variable rate among patients. This complicates clinical trials, as clinically relevant changes are difficult to capture within the typical duration of a trial. Therefore, predictors for disease progression are needed. We assessed if temporal increase of fat fraction (FF) in BMD follows a sigmoidal trajectory and whether fat fraction at baseline (FFbase) could therefore predict FF increase after 2 years (Delta FF). Thereafter, for two different MR-based parameters, we tested the additional predictive value to FFbase. We used 3-T Dixon data from the upper and lower leg, and multiecho spinecho MRI and 7-T P-31 MRS datasets from the lower leg, acquired in 24 BMD patients (age: 41.4 [SD 12.8] years). We assessed the pattern of increase in FF using mixed-effects modelling. Subsequently, we tested if indicators of muscle damage like standard deviation in water T-2 (stdT(2)) and the phosphodiester (PDE) over ATP ratio at baseline had additional value to FFbase for predicting Delta FF. The association between FFbase and Delta FF was described by the derivative of a sigmoid function and resulted in a peak Delta FF around 0.45 FFbase (fourth-order polynomial term: t = 3.7, p < .001). StdT(2) and PDE/ATP were not significantly associated with Delta FF if FFbase was included in the model. The relationship between FFbase and Delta FF suggests a sigmoidal trajectory of the increase in FF over time in BMD, similar to that described for Duchenne muscular dystrophy. Our results can be used to identify muscles (or patients) that are in the fast progressing stage of the disease, thereby facilitating the conduct of clinical trials.Orthopaedics, Trauma Surgery and Rehabilitatio

    Association of elbow flexor MRI fat fraction with loss of hand-to-mouth movement in patients with Duchenne muscular dystrophy

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    Background and Objectives To study the potential of quantitative MRI (qMRI) fat fraction (FF) as a biomarker in nonambulant patients with Duchenne muscular dystrophy (DMD), we assessed the additive predictive value of elbow flexor FF to age at loss of hand-to-mouth movement. Methods Nonambulant patients with DMD (age >= 8 years) were included. Four-point Dixon MRI scans of the right upper arm were performed at baseline and at the 12-, 18-, or 24-month follow-up. Elbow flexor FFs were determined from 5 central slices. Loss of hand-to-mouth movement was determined at study visits and by phone calls every 4 months. FFs were fitted to a sigmoidal curve by use of a mixed model with random slope to predict individual trajectories. The added predictive value of elbow flexor FF to age at loss of hand-to-mouth movement was calculated from a Cox model with the predicted FF as a time-varying covariate, yielding a hazard ratio. Results Forty-eight MRIs of 20 patients with DMD were included. The hazard ratio of a percent-point increase in elbow flexor FF for the time to loss of hand-to-mouth movement was 1.12 (95% confidence interval 1.04-1.21; p = 0.002). This corresponded to a 3.13-fold increase in the instantaneous risk of loss of hand-to-mouth movement in patients with a 10-percent points higher elbow flexor FF at any age. Discussion In this prospective study, elbow flexor FF predicted loss of hand-to-mouth movement independently of age. qMRI-measured elbow flexor FF can be used as a surrogate endpoint or stratification tool for clinical trials in nonambulant patients with DMD. Classification of Evidence This study provides Class II evidence that qMRI FF of elbow flexor muscles in patients with DMD predicts loss of hand-to-mouth movement independently of age.Neuro Imaging Researc

    Muscle fiber strain rates in the lower leg during ankle dorsi-/plantarflexion exercise

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    Static quantitative magnetic resonance imaging (MRI) provides readouts of structural changes in diseased muscle, but current approaches lack the ability to fully explain the loss of contractile function. Muscle contractile function can be assessed using various techniques including phase-contrast MRI (PC-MRI), where strain rates are quantified. However, current two-dimensional implementations are limited in capturing the complex motion of contracting muscle in the context of its three-dimensional (3D) fiber architecture. The MR acquisitions (chemical shift-encoded water–fat separation scan, spin echo-echoplanar imaging with diffusion weighting, and two time-resolved 3D PC-MRI) wereperformed at 3 T. PC-MRI acquisitions and performed with and without load at 7.5% of the maximum voluntary dorsiflexion contraction force. Acquisitions (3 T, chemical shift-encoded water–fat separation scan, spin echo-echo planar imaging with diffusion weighting, and two time-resolved 3D PC-MRI) were performed with and without load at 7.5% of the maximum voluntary dorsiflexion contraction force. Strain rates and diffusion tensors were calculated and combined to obtain strain rates along and perpendicular to the muscle fibers in seven lower leg muscles during the dynamic dorsi-/plantarflexion movement cycle. To evaluate strain rates along the proximodistal muscle axis, muscles were divided into five equal segments. t-tests were used to test if cyclic strain rate patterns (amplitude > 0) were present along and perpendicular to the muscle fibers. The effects of proximal-distal location and load were evaluated using repeated measures ANOVAs. Cyclic temporal strain rate patterns along and perpendicular to the fiber were found in all muscles involved in dorsi-/plantarflexion movement (p p p Radiolog

    A nurse-led sexual rehabilitation intervention after radiotherapy for gynecological cancer

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    Purpose: Although vaginal dilator use after combined pelvic radiation therapy and brachytherapy (RT/BT) is recommended to prevent vaginal shortening and stenosis, women fail to use them and experience sexual problems. A nurse-led sexual rehabilitation intervention targeting sexual recovery and vaginal dilatation was developed. Its feasibility was investigated during a prospective, longitudinal, observational pilot study. Methods: Four oncology nurses were specifically trained to conduct the intervention. Gynecologic cancer patients treated with RT/BT were assessed using (i) questionnaires on frequency of dilator use (monthly), sexual functioning, and sexual distress (at baseline and 1, 6, and 12 months) and psychological and relational distress (at 1, 6, and 12 months); (ii) semi-structured interviews (between 6 and 12 months); and (iii) consultation recordings (a random selection of 21 % of all consults). Results: Twenty participants were 26–71 years old (mean = 40). Eight participants discontinued participation after 3 to 9 months. At 6 months after RT, 14 out of 16 (88 %), and at 12 months 9 out of 12 (75 %), participants dilated regularly, either by having sexual intercourse or by using dilators. Sexual functioning improved between 1 and 6 months after RT, with further improvement at 12 months. Most participants reported that the intervention was helpful and the nurses reported having sufficient expertise and counseling skills. Conclusions: According to the pilot results, the intervention was feasible and promising for sexual rehabilitation and regular dilator use after RT. Its (cost-)effectiveness will be investigated in a randomized controlled trial

    Exploring the applicability of the pregnancy and childbirth outcome set: a mixed methods study

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    Objective: The International Consortium for Health Outcomes Measurement developed the Pregnancy and Childbirth (PCB) outcome set to improve value-based perinatal care. This set contains clinician-reported outcomes and patient-reported outcomes. We validated the set for use in the Netherlands by exploring its applicability among all end-users prior to implementation.Methods: A mixed-methods design was applied. A survey was performed to assess patients (n = 142), professionals (n = 134) and administrators (n = 35) views on the PCB set. To further explore applicability, separate focus groups were held with representatives of each of these groups.Results: The majority of survey participants agreed that the PCB set contains the most important outcomes. Patient-reported experience measures were considered relevant by the majority of participants. Perceived relevance of patient-reported outcome measures varied. Main themes from the focus groups were content of the set, data collection timing, implementation (also IT and transparency), and quality-based governance.Conclusion: This study supports suitability of the PCB outcome set for implementation, evaluation of quality of care and shared decision making in perinatal care.Practice Implications: Implementation of the PCB set may change existing care pathways of perinatal care. Focus on transparency of outcomes is required in order to achieve quality-based governance with proper IT solutions. (C) 2019 The Authors. Published by Elsevier B.V
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