218 research outputs found

    Dual-isotope 111In/177Lu SPECT imaging as a tool in molecular imaging tracer design

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    The synthesis, design and subsequent pre-clinical testing of new molecular imaging tracers are topic of extensive research in healthcare. Quantitative dual-isotope SPECT imaging is proposed here as a tool in the design and validation of such tracers, as it can be used to quantify and compare the biodistribution of a specific ligand and its nonspecific control ligand, labeled with two different radionuclides, in the same animal. Since the biodistribution results are not blurred by experimental or physiological inter-animal variations, this approach allows determination of the ligand's net targeting effect. However, dual-isotope quantification is complicated by crosstalk between the two radionuclides used and the radionuclides should not influence the biodistribution of the tracer. Here, we developed a quantitative dual-isotope SPECT protocol using combined 111Indium and 177Lutetium and tested this tool for a well-known angiogenesis-specific ligand (cRGD peptide) in comparison to a potential nonspecific control (cRAD peptide). Dual-isotope SPECT imaging of the peptides showed a similar organ and tumor uptake to single-isotope studies (cRGDfK-DOTA, 1.5±0.8%ID cm -3; cRADfK-DOTA, 0.2±0.1%ID cm -3), but with higher statistical relevance (p-value 0.007, n=8). This demonstrated that, for the same relevance, seven animals were required in case of a single-isotope test design as compared with only three animals when a dual-isotope test was used. Interchanging radionuclides did not influence the biodistribution of the peptides. Dual-isotope SPECT after simultaneous injection of 111In and 177Lu-labeled cRGD and cRAD was shown to be a valuable method for paired testing of the in vivo target specificity of ligands in molecular imaging tracer design. © 2012 John Wiley & Sons, Ltd

    KNGF-standaard: beweeginterventie kwetsbare ouderen

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    Gezien het steeds verder stijgende aantal mensen met één of meerdere chronische aandoeningen en de rechtstreeks daaraan gekoppelde stijging van de kosten in de gezondheidszorg, is het KNGF vanaf 2008 gestart met het ontwikkelen van de KNGF-standaarden beweeginterventies. Een KNGF-standaard Beweeginterventie stelt een voldoende competente fysiotherapeut in staat bij mensen met een chronische aandoening een actieve leefstijl te bevorderen en hun mate van fitheid te verhogen. Voorliggende standaard is gericht op kwetsbare ouderen. Er wordt, waar mogelijk, tot het niveau van de beweegnormen gestreefd naar het ontwikkelen en in stand houden van een actieve leefstijl en het verhogen van de fitheid. Daarnaast zal de fysiotherapeut aandacht besteden aan het inspanningsvermogen, de spierfunctie, verminderde range of motion (ROM) en balans, indien dit beperkende factoren zijn voor het opbouwen en/of onderhouden van een actieve leefstijl

    Increased bone resorption during lactation in pycnodysostosis

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    Pycnodysostosis, a rare autosomal recessive skeletal dysplasia, is caused by a deficiency of cathepsin K. Patients have impaired bone resorption in the presence of normal or increased numbers of multinucleated, but dysfunctional, osteoclasts. Cathepsin K degrades collagen type I and generates N-telopeptide (NTX) and the C-telopeptide (CTX) that can be quantified. Levels of these telopeptides are increased in lactating women and are associated with increased bone resorption. Nothing is known about the consequences of cathepsin K deficiency in lactating women. Here we present for the first time normalized blood and CTX measurements in a patient with pycnodysostosis, exclusively related to the lactation period. In vitro studies using osteoclasts derived from blood monocytes during lactation and after weaning further show consistent bone resorption before and after lactation. Increased expression of cathepsins L and S in osteoclasts derived from the lactating patient suggests that other proteinases could compensate for the lack of cathepsin K during the lactation period of pycnodysostosis patients.Diabetes mellitus: pathophysiological changes and therap

    KNGF-standaard: beweeginterventie kwetsbare ouderen

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    Health-related quality of life in patients with systemic sclerosis: evolution over time and main determinants

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    Objectives. In SSc patients, disease specific determinants that influence health-related quality of life (HRQoL) over time have not been described. We aim to, in patients with SSc, (i) evaluate if and how HRQoL changes over time, and (ii) assess how different SSc domains and functional impairments contribute to changes in HRQoL over time.Methods. All SSc patients from the Leiden SSc cohort were included; patients with disease duration <24 months were classified as incident cases. HRQoL was assessed prospectively on an annual basis using the EQ-5D and the SF36. To assess baseline associations between clinical characteristics and HRQoL, linear regressions were performed. To identify possible associations between SSc characteristics and HRQoL change over time, linear mixed models were performed in both incident and prevalent cases.Results. In total, 492 SSc patients were included (n = 202 incident cases), with a median follow-up duration of 3.4 years. At baseline, presence of organ involvement was independently associated with a worse SF36 physical component score and lower EQ-5D score. Over time, gastrointestinal symptoms, Raynaud and digital ulcers were independently associated with deterioration of HRQoL in both incident and prevalent cases. In prevalent cases, pulmonary arterial hypertension (PAH) was associated with a decrease in HRQoL over time. Worse functioning as measured by six-min walking distance, mouth-opening, finger-to-palm distance and grip-strength contributed significantly to deterioration of HRQoL over time.Conclusion. In SSc, key clinical burdens that contribute to worsening of HRQoL over time include digital ulcers, Raynaud and gastrointestinal involvement. In addition, PAH is a significant burden in prevalent disease.Pathophysiology and treatment of rheumatic disease

    Lung function is associated with minimal EQ-5D changes over time in patients with systemic sclerosis

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    In systemic sclerosis (SSc) therapeutic efforts are often directed to prevent progressive respiratory impairment, but it is unclear to what extent changes in pulmonary function tests (PFTs) are associated with health-related quality of life (HRQoL). The aim of our study is to evaluate how modifications in PFTs contribute to longitudinal variations in HRQoL, assessed through the multidimensional questionnaire EQ-5D, in patients with SSc. We included SSc patients with forced vital capacity (FVC%), diffusing capacity of the lungs for carbon monoxide (DLCO%) and EQ-5D assessed in at least two visits. The EQ-5D consists of two parts, a utility score ranging from - 0.59 to 1, and a 0-100 Visual Analogue Scale (VAS). Higher values represent better health. The association between changes in FVC% and DLCO%, and evolution of EQ-5D over time, was investigated using generalized estimating equations. Three hundred seventy-eight patients were included, accounting for a total of 1619 measurements. The models showed that improvement in FVC% is significantly associated with increase in both utility score (beta = 0.001; 95% CI 0.000 to 0.002; p = 0.003) and VAS over time (beta = 0.188; 95% CI 0.111 to 0.264; p < 0.001). Moreover, improvement in DLCO% is longitudinally associated with increase in utility score (beta = 0.001; 95% CI 0.000 to 0.002; p = 0.038), while the results for VAS were non-significant (beta = 0.020; 95% CI -0.079 to 0.120; p = 0.690). We show that change in PFTs has a significant, although minor, impact on HRQoL as measured by EQ-5D in SSc.Pathogenesis and treatment of chronic pulmonary disease

    Camera-based objective measures of Parkinson's disease gait features

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    OBJECTIVE: Parkinson's disease is a common, age-related, neurodegenerative disease, affecting gait and other motor functions. Technological developments in consumer imaging are starting to provide high-quality, affordable tools for home-based diagnosis and monitoring. This pilot study aims to investigate whether a consumer depth camera can capture changes in gait features of Parkinson's patients. The dataset consisted of 19 patients (tested in both a practically defined OFF phase and ON phase) and 8 controls, who performed the "Timed-Up-and-Go" test multiple times while being recorded with the Microsoft Kinect V2 sensor. Camera-derived features were step length, average walking speed and mediolateral sway. Motor signs were assessed clinically using the Movement Disorder Society Unified Parkinson's Disease Rating Scale. RESULTS: We found significant group differences between patients and controls for step length and average walking speed, showing the ability to detect Parkinson's features. However, there were no differences between the ON and OFF medication state, so further developments are needed to allow for detection of small intra-individual changes in symptom severity

    Randomized trial of Legflow® paclitaxel eluting balloon and stenting versus standard percutaneous transluminal angioplasty and stenting for the treatment of intermediate and long lesions of the superficial femoral artery (RAPID trial): Study protocol for a randomized controlled trial

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    Background: Restenosis after percutaneous transluminal angioplasty (PTA) of the superficial femoral artery (SFA) may occur in 45% of patients at 2 years follow-up. Paclitaxel-coated balloons have been found to reduce neointimal hyperplasia, and thus reduce restenosis. Recently, the Legflow® paclitaxel-coated balloon (Cardionovum Sp.z.o.o., Warsaw, Poland) (LPEB) has been introduced. This balloon is covered with shellac, a Food and Drug Administration (FDA) approved natural resin, to obtain an equally distributed tissue concentration of paclitaxel. The RAPID trial is designed to assess restenosis after PTA using the Legflow balloon combined with nitinol stenting versus uncoated balloons with nitinol stenting in SFA lesions >5 cm.Methods/Design: A total of 176 adult patients with Rutherford class 2 to class 6 symptoms due to intermediate (5-15 cm) or long (>15 cm) atherosclerotic lesions in the SFA will be randomly allocated for treatment with LPEB with nitinol stenting or uncoated balloon angioplasty with stenting. Stenting will be performed using the Supera® stent in both groups (IDEV Technologies Inc., Webster, TX). The primary endpoint is the absence of binary restenosis of the treated SFA segment. Secondary outcomes are target lesion revascularization (TLR), clinical and hemodynamic outcome, amputation rate, mortality rate, adverse events, and device-specific adverse events. Follow up consists of four visits in which ankle-brachial indices (ABI), toe pressure measurements, and duplex ultrasound (DUS) will be performed. Furthermore, a peripheral artery questionnaire (PAQ) will be completed by the patients at each follow-up. In the event that DUS reveals a symptomatic >50% restenosis, or a >75% asymptomatic restenosis, additional digital subtraction angiography will be performed with any necessary re-intervention.Discussion: The RAPID trial is a multicenter randomized controlled patient blind trial that will provide evidence concerning whether the use of the Legflow paclitaxel/shellac coated balloons with nitinol stenting significantly reduces the frequency of restenosis in intermediate and long SFA lesions compared to standard PTA and stenting.Trial registration: ISRCTN47846578
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