698 research outputs found
Severe hepatic and pulmonary involvement in Rendu-Osler-Weber syndrome
We report the case of a young woman with hereditary hemorrhagic telangiectasia (HHT) with severe liver involvement and pulmonary shunting. The medical imaging in this patient illustrates the severe shunting that can occur in these patients who often are asymptomatic. By showing this case, we want to highlight the role of liver transplantation in HHT with hepatic involvement
Molecular imaging of tumor-associated angiogenesis using a novel magnetic resonance imaging contrast agent targeting αvβ3 integrin
The recent introduction of biological anticancer therapy has renewed the interest in functional imaging of tumor-associated angiogenesis (TAA) as a tool to monitor early therapy response. The present study evaluated imaging of TAA using P1227, a novel, small molecular magnetic resonance imaging (MRI) probe targeting alpha(v)beta(3) integrin.
HT29 human colorectal cancers were grown in athymic mice. Dynamic MRI was performed using a three-dimensional VIBE sequence up to 110 min after injection of P1227 or gadolinium-tetraazacyclododecane tetraacetic acid (Gd-DOTA). Specificity was assessed by using P1227 1 h after intravenous administration of the alpha(v)beta(3) inhibitor cilengitide. Regions of interest were drawn encompassing the tumor rim and normal muscle. Imaging data were compared with microvessel density and alpha(v)beta(3) expression.
Using P1227, specific enhancement of the angiogenic tumor rim, but not of normal muscle, was observed, whereas Gd-DOTA enhanced tumor and normal muscle. After administering cilengitide, enhancement with P1227, but not with DOTA, was significantly suppressed during the first 20 min. When using P1227, a significant correlation was observed between normalized enhancement of the tumor rim and immunohistochemical alpha(v)beta(3) integrin expression.
Molecular MRI using a small monogadolinated tracer targeting alpha(v)beta(3) integrin and moderate magnetic field strength holds promise in assessing colorectal TAA
Noninvasive monitoring of radiotherapy-induced microvascular changes using dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) in a colorectal tumor model
To examine dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with a macromolecular contrast agent (P792) to visualize effects of radiotherapy (RT) on microvascular leakage in a colorectal cancer model.Journal Articleinfo:eu-repo/semantics/publishe
Dopaminergic and noradrenergic modulation of stress-induced alterations in brain activation associated with goal-directed behaviour
BACKGROUND: Acute stress is thought to reduce goal-directed behaviour, an effect purportedly associated with stress-induced release of catecholamines. In contrast, experimentally increased systemic catecholamine levels have been shown to increase goal-directed behaviour. Whether experimentally increased catecholamine function can modulate stress-induced reductions in goal-directed behaviour and its neural substrates, is currently unknown. AIM: To assess whether and how experimentally induced increases in dopamine and noradrenaline contribute to the acute stress effects on goal-directed behaviour and associated brain activation. METHODS: One hundred participants underwent a stress induction protocol (Maastricht acute stress test; MAST) or a control procedure and received methylphenidate (MPH) (40 mg, oral) or placebo according to a 2 × 2 between-subjects design. In a well-established instrumental learning paradigm, participants learnt stimulus–response–outcome associations, after which rewards were selectively devalued. Participants’ brain activation and associated goal-directed behaviour were assessed in a magnetic resonance imaging scanner at peak cortisol/MPH concentrations. RESULTS: The MAST and MPH increased physiological measures of stress (salivary cortisol and blood pressure), but only MAST increased subjective measures of stress. MPH modulated stress effects on activation of brain areas associated with goal-directed behaviour, including insula, putamen, amygdala, medial prefrontal cortex, frontal pole and orbitofrontal cortex. However, MPH did not modulate the tendency of stress to induce a reduction in goal-directed behaviour. CONCLUSION: Our neuroimaging data suggest that MPH-induced increases in dopamine and noradrenaline reverse stress-induced changes in key brain regions associated with goal-directed behaviour, while behavioural effects were absent. These effects may be relevant for preventing stress-induced maladaptive behaviour like in addiction or binge eating disorder
Differentiation between peri-anastomotic inflammatory changes and local recurrence following neoadjuvant radiochemotherapy surgery for colorectal cancer using visual and semiquantitative analysis of PET-CT data
Aim. The aim of this study was to evaluate the usefulness of visual and semiquantitative [F-18]fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) data for the diagnosis of peri-anastomotic colorectal cancer recurrence, taking into account the time period between surgery and [F-18]FDG PET-CT scanning.
Methods. The study population consisted of 70 patients who had prior preoperative radiochemotherapy and surgical resection of the primary tumor and who underwent whole body [F-18]FDG PET-CT scanning for the detection of recurrent disease. Visual and semiquantitative (SUVmax) analysis of [F-18]FDG uptake at the peri-anastomosis was performed. The final diagnosis was based on pathological proof or clinical and/or imaging follow-up data.
Results. On visual reading, 27 patients exhibited increased [F-18]FDG uptake at the peri-anastomosis. Of these, 11 (41%) patients had a local tumor recurrence and 16 (59%) had no recurrent tumor. Among the 43 patients without increased [F-18]FDG uptake at the peri-anastomosis, none had local tumor recurrence. On semiquantitation, SUVmax in patients with and without a local recurrence overlapped. However, when the time period between surgery and [F-18]FDG PET-CT scanning was taken into account, overlap of SUVmax was mainly observed within a postoperative period of <= 12 months; thereafter, a threshold SUVmax of 3.2 discriminated between benign and malignant lesions in all but one patient.
Conclusion. In our series, visually increased [F-18]FDG uptake at the peri-anastomosis was 100% sensitive but non-specific (73% specificity) for the diagnosis of local tumor recurrence. On the other hand, normal [F-18]FDG uptake at the peri-anastomosis precluded a local tumor recurrence (a negative predictive value of 100%). In addition, semiquantitative (SUVmax) analysis of [F-18]FDG uptake at the peri-anastomosis may increase specificity (up to 97%), while preserving maximum sensitivity, if the postoperative period is >12 months
Low back pain: a call for action.
Low back pain is the leading worldwide cause of years lost to disability and its burden is growing alongside the increasing and ageing population.1Because these population shifts are more rapid in low-income and middle-income countries, where adequate resources to address the problem might not exist, the effects will probably be more extreme in these regions. Most low back pain is unrelated to specific identifiable spinal abnormalities, and our Viewpoint, the third paper in this Lancet Series,2,3is a call for action on this global problem of low back pain
Boringen op het Martelarenplein te Leuven
Dit rapport werd ingediend bij het agentschap samen met een aantal afzonderlijke digitale bijlagen. Een aantal van deze bijlagen zijn niet inbegrepen in dit pdf document en zijn niet online beschikbaar. Sommige bijlagen (grondplannen, fotos, spoorbeschrijvingen, enz.) kunnen van belang zijn voor een betere lezing en interpretatie van dit rapport. Indien u deze bijlagen wenst te raadplegen kan u daarvoor contact opnemen met: [email protected]
Biochar characterization of raw versus spent common ivy: Inorganic nutrient behavior
Hedera sp., common Ivy, a lignocellulosic evergreen vine, is commonly seen in gardens and yards all over the globe. It is an excellent candidate to be applied in vertical green walls to improve ecosystems in future green cities (e.g. fine particulate matter adsorption). These green walls need to be trimmed regularly, thus leaving a major residue stream which could be promising as biomass feedstock for biochar fertilizer production. However, common Ivy contains valuable compounds (e.g. etheric oils and triterpene saponins) increasing the process’ added value. These should preferably be extracted prior to thermal conversion. The aim of this study is therefore to investigate the influence of extraction methods on the final properties of common ivy’s biochar using conventional pyrolysis. Investigated extraction methods include a Soxhlet ethanol extraction and a steam distillation, to obtain respectively a triterpene saponin and volatile oil extract. The influence of these extractions on the biochar properties was studied by comparing the thermal conversion and biochar properties of spent, extracted, biomass with raw biomass. Studied properties include biochar yield, elemental composition (CHNO), amount of inorganic nutrients, specific surface area, and presence of harmful heavy metals. The guidelines of the European Biochar Certificate are used to evaluate said properties. Furthermore, the pyrolysis process parameters, temperature and heating rate, were optimized to improve said biochar properties for application as fertilizer. Tested pyrolysis temperatures were 400, 550 and 700 °C. Results show that biochar yield from raw ivy was inversely proportional with pyrolysis temperature ranging from 29.6 ± 0.6% at 400 °C, 25.4% ± 0.03 at 550 °C and 23.0 ± 0.06 % at 700 °C. It was found that steam distillation lowers the amount of heavy metals in the material, whilst the inorganic nutrients are retained, thus enhancing the biochar’s potential as fertilizer. Furthermore, nitrogen content remained constant, around 2%, before and after pyrolysis both for raw and spent ivy, these results indicate that high-quality biochars were produced. To further understand biochar’s chemical behavior in soils, structural properties and morphology are being investigated further, specific surface area via BET, general pore structure using SEM, surface functional groups with FT-IR and, aromaticity with CP/MAS 13C NMR results will be presented accordingly
FDG-PET is a predictor of metabolic response to chemotherapy in metastatic colorectal cancer (mCRC)
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