Background: Amyloidoses are characterized by the extracellular deposition of insoluble fibrillar proteinaceous aggregates highly organized into cross-β structure and referred to as amyloid fibrils. Nowadays, the diagnosis of these diseases remains tedious and involves multiple examinations while an early and accurate protein typing is crucial for the patients' treatment. Routinely used neuroimaging techniques such as magnetic resonance imaging (MRI) and positron emission tomography (PET) using Pittsburgh compound B, [(11)C]PIB, provide structural information and allow to assess the amyloid burden, respectively, but cannot discriminate between different amyloid deposits.
View Article and Find Full Text PDFThe use of nanoparticles to enhance the effect of radiation-based cancer treatments is a growing field of study and recently, even nanoparticle-induced improvement of proton therapy performance has been investigated. Aiming at a clinical implementation of this approach, it is essential to characterize the mechanisms underlying the synergistic effects of nanoparticles combined with proton irradiation. In this study, we investigated the effect of platinum- and gadolinium-based nanoparticles on the nanoscale damage induced by a proton beam of therapeutically relevant energy (150 MeV) using plasmid DNA molecular probe.
View Article and Find Full Text PDFGadolinium based nanoparticles (GBNs, diameter 2.9±0.2nm), have promising biodistribution properties for theranostic use in-vivo.
View Article and Find Full Text PDFUnlabelled: Nanomedicine is proposed as a novel strategy to improve the performance of radiotherapy. High-Z nanoparticles are known to enhance the effects of ionizing radiation. Recently, multimodal nanoparticles such as gadolinium-based nanoagents were proposed to amplify the effects of x-rays and g-rays and to improve MRI diagnosis.
View Article and Find Full Text PDFOwing to the high atomic number (Z) of gold element, the gold nanoparticles appear as very promising radiosensitizing agents. This character can be exploited for improving the selectivity of radiotherapy. However, such an improvement is possible only if irradiation is performed when the gold content is high in the tumor and low in the surrounding healthy tissue.
View Article and Find Full Text PDFOwing to the high atomic number (Z) of gold element, the gold nanoparticles appear as very promising radiosensitizing agents. This character can be exploited for improving the selectivity of radiotherapy. However, such an improvement is possible only if irradiation is performed when the gold content is high in the tumor and low in the surrounding healthy tissue.
View Article and Find Full Text PDFThis study aims to investigate gadolinium-based nanoparticles (Gd-HNP) for in vitro labeling of human plasmacytoid dendritic cells (HuPDC) to allow for in vivo tracking and HuPDC quantifying using magnetic resonance imaging (MRI) following parenteral injection. Human plasmacytoid DC were labeled (LabHuPDC) with fluorescent Gd-HNP (Gd-FITC-HNP) and injected via intraperitoneal and intravenous routes in 4-5 NOD-SCID β2m(-/-)mice (treated mice = TM). Control mice (CM) were similarly injected with unlabeled HuPDC.
View Article and Find Full Text PDFOver the last few decades, nanoparticles have been studied in theranostic field with the objective of exhibiting a long circulation time through the body coupled to major accumulation in tumor tissues, rapid elimination, therapeutic potential and contrast properties. In this context, we developed sub-5 nm gadolinium-based nanoparticles that possess in vitro efficient radiosensitizing effects at moderate concentration when incubated with head and neck squamous cell carcinoma cells (SQ20B). Two main cellular internalization mechanisms were evidenced and quantified: passive diffusion and macropinocytosis.
View Article and Find Full Text PDFBackground: Micrometric and nanometric particles are increasingly used in different fields and may exhibit variable toxicity levels depending on their physicochemical characteristics. The aim of this study was to determine the impact of the size parameter on cellular uptake and biological activity, working with well-characterized fluorescent particles. We focused our attention on macrophages, the main target cells of the respiratory system responsible for the phagocytosis of the particles.
View Article and Find Full Text PDFGadolinium-based nanoparticles are novel objects with interesting physical properties, allowing their use for diagnostic and therapeutic applications. Gadolinium-based nanoparticles were imaged following intravenous injection in healthy rats and rats grafted with 9L gliosarcoma tumors using magnetic resonance imaging and scintigraphic imaging. Quantitative biodistribution using gamma-counting of each sampled organ confirmed that these nanoparticles were rapidly cleared essentially by renal excretion.
View Article and Find Full Text PDFJ Nanosci Nanotechnol
September 2011
Since radiotherapy is widely used in cancer treatment, it is essential to develop strategies which lower the irradiation burden while increasing efficacy and become efficient even in radio resistant tumors. Our new strategy is relying on the development of solid hybrid nanoparticles based on rare-earth such as gadolinium. In this paper, we then evidenced that gadolinium-based particles can be designed to enter efficiently into the human glioblastoma cell line U87 in quantities that can be tuned by modifying the incubation conditions.
View Article and Find Full Text PDFUltrasmall gadolinium-based nanoparticles (GBNs) induce both a positive contrast for magnetic resonance imaging and a radiosentizing effect. The exploitation of these characteristics leads to a greater increase in lifespan of rats bearing brain tumors since the radiosensitizing effect of GBNs can be activated by X-ray microbeams when the gadolinium content is, at the same time, sufficiently high in the tumor and low in the surrounding healthy tissue. GBNs exhibit therefore an interesting potential for image-guided radiotherapy.
View Article and Find Full Text PDFAn in vitro MR-assay for superparamagnetic iron oxide (SPIO) particle cell labelling assessment via three-dimensional quantitative T(2) (*) MR microscopy was proposed. On high-resolution images, and due to the high susceptibility difference between the particles and the surrounding medium, SPIO internalized in cells induces signal loss which may be counted and measured on T(2) (*) maps. The increase in both labelled cell percentage and the average perturbation volume with an added amount of iron in the incubation medium proved that intracellular iron uptake is dependent upon the initial concentration of incubation iron.
View Article and Find Full Text PDFTwo imaging methods, MSSAVE (Multiple echo SubSlice AVEraging imaging), based on sub-slice averaging and MGESEPI (Multiple echo Gradient-Echo Slice-Excitation Profile Imaging), based on over-sampling in the slice direction, are proposed for single-scan quantitative T(2)* evaluation with susceptibility artifact compensation. Their potentials in terms of sensitivity, minimum performance time, susceptibility artifact reduction and T(2)* quantitation quality, were compared with existing single-scan methods such as classical FLASH two- or three-dimensional or z-shimmed methods both in vitro and in vivo in normal rat brain. MGESEPI offered good quality T(2)* maps nearly free of artifacts but required a long acquisition time.
View Article and Find Full Text PDFThe principles of cancer pain management are well established, but evidence suggests that these are not incorporated into daily practice and patients are still in pain. Deficiencies in knowledge and inappropriate attitudes towards the use of opioids may partially explain why the management of cancer pain is still such a widespread problem. This study assessed the knowledge and attitudes of 135 nursing and medical staff working in a surgical unit, before and after working with a newly established Hospital Palliative Care Team.
View Article and Find Full Text PDFWe have previously shown that patients with multiple sclerosis (MS) have increased T cell responses to the immunodominant region (residues 184-209) of myelin proteolipid protein (PLP). The present study investigated whether this reactivity fluctuates over time and correlates with disease activity. We performed monthly limiting dilution assays for 12-16 mo in four healthy subjects and five patients with relapsing-remitting MS to quantify the frequencies of circulating T cells proliferating in response to PLP(41-58), PLP(184-199), PLP(190-209), myelin basic protein (MBP), MBP(82-100), and tetanus toxoid.
View Article and Find Full Text PDFA rare case of retro-odontoid disc sequestration causing significant cord compression and progressive neurological deterioration is presented. The clinical history, radiology, treatment and pathogenesis of the case are described, along with a review of the relevant literature.
View Article and Find Full Text PDFThree cases of deep cerebral vein thrombosis presenting as encephalitic illnesses are described. Thyrotoxicosis was present in one case, ulcerative colitis in one case and an anticardiolipin antibody was detected in two cases. All three patients were on oestrogen and progesterone.
View Article and Find Full Text PDFBackground: The clinical presentation, course, and radiological spectrum of bronchiolitis obliterans organising pneumonia (BOOP) is still being characterised to aid differentiation from other causes of organising pneumonia.
Aims: To define the clinical presentation, response to therapy, and radiological spectrum of BOOP.
Methods: Fifteen cases of BOOP were retrospectively reviewed.
A case is presented of actinomycosis that involved the lung and the liver, which was diagnosed after a computed-tomographic-guided needle biopsy of a liver mass. The diagnosis was made on histological grounds that were based on the staining and morphological characteristics of Actinomyces spp. Imaging techniques suggested a communication between the lung and liver lesions.
View Article and Find Full Text PDFProlactin-secreting adenomas, the commonest of the pituitary tumours, are being recognised with increasing frequency in men. Their appearance and behaviour differ from those occurring in women, being typically larger and more aggressive. We describe the clinical features and radiological findings of three prolactinomas in young males and review the literature.
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