23 research outputs found

    Logic engine and renderer for process data modules

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    Our assignment to develop a logic engine for support execution of S1000D process Data Modules version 4.0, is given by CORENA Norge A/S. This logic engine can take input from users and/or external applications, such as sensors, to decide its next step in a flow of process Data Modules. It can branch and loop through the selected process Data Module. The logic engine will be an interpreter for process Data Modules. We will make it a stand-alone logic engine in a web based application running on Jetty/Tomcat. The user of the application should be able to move back and forth through the steps using previous and next buttons. The user should be able to save the session to continue at a later time. The logic engine should support the International S1000D Specification Issue 4.0

    Initial Observations of Endovascular Aneurysm Repair Using Dyna-CT

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    Mn-alginate gels as a novel system for controlled release of Mn2+ in manganese-enhanced MRI

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    The aim of the present study was to test alginate gels of different compositions as a system for controlled release of manganese ions (Mn2+) for application in manganese‐enhanced MRI (MEMRI), in order to circumvent the challenge of achieving optimal MRI resolution without resorting to high, potentially cytotoxic doses of Mn2+. Elemental analysis and stability studies of Mn‐alginate revealed marked differences in ion binding capacity, rendering Mn/Ba‐alginate gels with high guluronic acid content most stable. The findings were corroborated by corresponding differences in the release rate of Mn2+ from alginate beads in vitro using T1‐weighted MRI. Furthermore, intravitreal (ivit) injection of Mn‐alginate beads yielded significant enhancement of the rat retina and retinal ganglion cell (RGC) axons 24 h post‐injection. Subsequent compartmental modelling and simulation of ivit Mn2+ transport and concentration revealed that application of slow release contrast agents can achieve a significant reduction of ivit Mn2+ concentration compared with bolus injection. This is followed by a concomitant increase in the availability of ivit Mn2+ for uptake by RGC, corresponding to significantly increased time constants. Our results provide proof‐of‐concept for the applicability of Mn‐alginate gels as a system for controlled release of Mn2+ for optimized MEMRI application

    Dynamic contrast enhanced MRI detects early response to adoptive NK cellular immunotherapy targeting the NG2 proteoglycan in a rat model of glioblastoma

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    There are currently no established radiological parameters that predict response to immunotherapy. We hypothesised that multiparametric, longitudinal magnetic resonance imaging (MRI) of physiological parameters and pharmacokinetic models might detect early biological responses to immunotherapy for glioblastoma targeting NG2/CSPG4 with mAb9.2.27 combined with natural killer (NK) cells. Contrast enhanced conventional T1-weighted MRI at 7±1 and 17±2 days post-treatment failed to detect differences in tumour size between the treatment groups, whereas, follow-up scans at 3 months demonstrated diminished signal intensity and tumour volume in the surviving NK+mAb9.2.27 treated animals. Notably, interstitial volume fraction (ve), was significantly increased in the NK+mAb9.2.27 combination therapy group compared mAb9.2.27 and NK cell monotherapy groups (p = 0.002 and p = 0.017 respectively) in cohort 1 animals treated with 1 million NK cells. ve was reproducibly increased in the combination NK+mAb9.2.27 compared to NK cell monotherapy in cohort 2 treated with increased dose of 2 million NK cells (p<0.0001), indicating greater cell death induced by NK+mAb9.2.27 treatment. The interstitial volume fraction in the NK monotherapy group was significantly reduced compared to mAb9.2.27 monotherapy (p<0.0001) and untreated controls (p = 0.014) in the cohort 2 animals. NK cells in monotherapy were unable to kill the U87MG cells that highly expressed class I human leucocyte antigens, and diminished stress ligands for activating receptors. A significant association between apparent diffusion coefficient (ADC) of water and ve in combination NK+mAb9.2.27 and NK monotherapy treated tumours was evident, where increased ADC corresponded to reduced ve in both cases. Collectively, these data support histological measures at end-stage demonstrating diminished tumour cell proliferation and pronounced apoptosis in the NK+mAb9.2.27 treated tumours compared to the other groups. In conclusion, ve was the most reliable radiological parameter for detecting response to intralesional NK cellular therapy

    Loss or mislocalization of aquaporin-4 affects diffusion properties and intermediary metabolism in gray matter of mice

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    The first aim of this study was to determine how complete or perivascular loss of aquaporin-4 (AQP4) water channels affects membrane permeability for water in the mouse brain grey matter in the steady state. Time-dependent diffusion magnetic resonance imaging was performed on global Aqp4 knock out (KO) and α-syntrophin (α-syn) KO mice, in the latter perivascular AQP4 are mislocalized, but still functioning. Control animals were corresponding wild type (WT) mice. By combining in vivo diffusion measurements with the effective medium theory and previously measured extra-cellular volume fractions, the effects of membrane permeability and extracellular volume fraction were uncoupled for Aqp4 and α-syn KO. The second aim was to assess the effect of α-syn KO on cortical intermediary metabolism combining in vivo [1-13C]glucose and [1,2-13C]acetate injection with ex vivo 13C MR spectroscopy. Aqp4 KO increased the effective diffusion coefficient at long diffusion times by 5%, and a 14% decrease in membrane water permeability was estimated for Aqp4 KO compared with WT mice. α-syn KO did not affect the measured diffusion parameters. In the metabolic analyses, significantly lower amounts of [4-13C]glutamate and [4-13C]glutamine, and percent enrichment in [4-13C]glutamate were detected in the α-syn KO mice. [1,2-13C]acetate metabolism was unaffected in α-syn KO, but the contribution of astrocyte derived metabolites to GABA synthesis was significantly increased. Taken together, α-syn KO mice appeared to have decreased neuronal glucose metabolism, partly compensated for by utilization of astrocyte derived metabolites

    The effect of nanoparticle polyethylene glycol surface density on ligand-directed tumor targeting studied in vivo by dual modality imaging

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    The development and application of nanoparticles as in vivo delivery vehicles for therapeutic and/or diagnostic agents has seen a drastic growth over the last decades. Novel imaging techniques allow real-time in vivo study of nanoparticle accumulation kinetics at the level of the cell and targeted tissue. Successful intravenous application of such nanocarriers requires a hydrophilic particle surface coating, of which polyethylene glycol (PEG) has become the most widely studied and applied. In the current study, the effect of nanoparticle PEG surface density on the targeting efficiency of ligand-functionalized nanoemulsions was investigated. We synthesized 100 nm nanoemulsions with a PEG surface density varying from 5 to 50 mol %. Fluorescent and paramagnetic lipids were included to allow their multimodal detection, while RGD peptides were conjugated to the PEG coating to obtain specificity for the α(v)β(3)-integrin. The development of a unique experimental imaging setup allowed us to study, in real time, nanoparticle accumulation kinetics at (sub)-cellular resolution in tumors that were grown in a window chamber model with confocal microscopy imaging, and at the macroscopic tumor level in subcutaneously grown xenografts with magnetic resonance imaging. Accumulation in the tumor occurred more rapidly for the targeted nanoemulsions than for the nontargeted versions, and the PEG surface density had a strong effect on nanoparticle targeting efficiency. Counterintuitively, yet consistent with the PEG density conformation models, the highest specificity and targeting efficiency was observed at a low PEG surface densit

    Cyclic Arginine–Glycine–Aspartate‐Decorated Lipid Nanoparticle Targeting toward Inflammatory Lesions Involves Hitchhiking with Phagocytes

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    Abstract Active‐targeting nanomedicine formulations have an intricate in vivo behavior. Nanomedicines developed to target endothelial αvβ3‐integrin are recently demonstrated to display extensive uptake by circulating phagocytes. These phagocytes show inherent tumor‐homing capacities and therefore are capable of actively delivering the endocytosed nanomaterial in lesions. Here, the targeting kinetics and mechanisms of cyclic arginine–glycine–aspartate (cRGD)‐decorated lipid nanoparticles (NPs) toward activated vasculature in inflamed lesions during wound healing are studied. The cRGD‐NP targeting toward inflamed lesions is identified to be mechanistically similar to the NP accumulation in cancerous lesions. Through a complementary experimental approach, it is observed that circulating phagocytes engage cRGD‐NPs and are subsequently homed to the inflamed endothelium. The inflammation‐associated phagocytes remain static among endothelial cells upon targeting, resulting in the extensive presence of cRGD‐NP‐positive phagocytes in the angiogenic vessels. Hence, phagocytic immune cells contribute to cRGD‐NP targeting toward angiogenesis. This mechanistic study underlines the need for detailed investigations of NP in vivo behavior. This is critically important for the realization of NPs potential as advanced (immunological) therapeutic agents

    The Effect of Nanoparticle Polyethylene Glycol Surface Density on Ligand-Directed Tumor Targeting Studied <i>in Vivo</i> by Dual Modality Imaging

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    The development and application of nanoparticles as <i>in vivo</i> delivery vehicles for therapeutic and/or diagnostic agents has seen a drastic growth over the last decades. Novel imaging techniques allow real-time <i>in vivo</i> study of nanoparticle accumulation kinetics at the level of the cell and targeted tissue. Successful intravenous application of such nanocarriers requires a hydrophilic particle surface coating, of which polyethylene glycol (PEG) has become the most widely studied and applied. In the current study, the effect of nanoparticle PEG surface density on the targeting efficiency of ligand-functionalized nanoemulsions was investigated. We synthesized 100 nm nanoemulsions with a PEG surface density varying from 5 to 50 mol %. Fluorescent and paramagnetic lipids were included to allow their multimodal detection, while RGD peptides were conjugated to the PEG coating to obtain specificity for the α<sub><i>v</i></sub>β<sub><i>3</i></sub>-integrin. The development of a unique experimental imaging setup allowed us to study, in real time, nanoparticle accumulation kinetics at (sub)-cellular resolution in tumors that were grown in a window chamber model with confocal microscopy imaging, and at the macroscopic tumor level in subcutaneously grown xenografts with magnetic resonance imaging. Accumulation in the tumor occurred more rapidly for the targeted nanoemulsions than for the nontargeted versions, and the PEG surface density had a strong effect on nanoparticle targeting efficiency. Counterintuitively, yet consistent with the PEG density conformation models, the highest specificity and targeting efficiency was observed at a low PEG surface density
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