Gadolinium

A 23-year-old Taiwanese female presented with intermittent twitching of the left eyelid and progressive left facial weakness for 10 months. Physical examination revealed grade II facial palsy on her left side. A white to pinkish mass with blood vessels on its surface was found behind the left intact tympanic membrane . Contrast-enhanced coronal MRI showed that the main tumor, about 2 ϫ 1 cm in size, arose from the second genu and the mastoid segment of the facial nerve . An extended transmastoid approach was used to expose the tumor by microscope.

Gadolinium vibronic side band luminescent spectroscopy (GVSBLS) is used to probe osmolyteinduced changes in the hydrogen bond strength between first and second shell waters on the surface of free Gd 3+ and Gd 3+ coordinated to EDTA and to structured calcium binding peptides in solution. In parallel, Raman is used to probe the corresponding impact of the same set of osmolytes on hydrogen bonding among waters in the bulk phase. Increasing concentration of added urea is observed to progressively weaken the hydrogen bonding within the hydration layer but has minimal observed impact on bulk water. In contrast polyols are observed to enhance hydrogen bonding in both the hydration layer and the bulk with the amplitude being polyol dependent with trehalose being more effective than sucrose, glucose or glycerol. The observed patterns indicate that size and properties of the osmolyte as well as the local architecture of the specific surface site of hydration impacts preferential exclusion effects and local hydrogen bond strength. Correlation of the vibronic spectra with CD measurements on the peptides as a function of added osmolytes shows an increase in secondary structure with added polyols and that the progressive weakening of the hydrogen bonding upon addition of urea first increases water occupancy within the peptide and only subsequently does the peptide unfold. The results support models in which the initial steps in the unfolding process involves osmolyte induced enhancement of water occupancy within the interior of the protein.

It has been presupposed that the thermodynamic stability constant (K(therm)) of gadolinium-based MRI chelates relate to the risk of precipitating nephrogenic systemic fibrosis. The present study compared low-K(therm) gadodiamide with high-K(therm) gadoteridol in cultured fibroblasts and rats with uninephrectomies. Gadolinium content was assessed using scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy in paraffin-embedded tissues. In vitro, fibroblasts demonstrated dose-dependent fibronectin generation, transforming growth factor-β production, and expression of activated myofibroblast stress fiber protein α-smooth muscle actin. There were negligible differences with respect to toxicity or proliferation between the two contrast agents. In the rodent model, gadodiamide treatment led to greater skin fibrosis and dermal cellularity than gadoteridol. In the kidney, both contrast agents led to proximal tubule vacuolization and increased fibronectin accumulatio...

ESUR guideline: gadolinium-based contrast media and nephrogenic systemic fibrosis Overview Nephrogenic systemic fibrosis (NSF), previously called nephrogenic fibrosing dermopathy, was described in 1997 but was only linked to exposure to gadolinium-based contrast media (Gd-CM) in 2006. Information about NSF continues to be collected. It is very important that a record is always kept of the type and amount of each injection of Gd-CM given. all cases of NSF are reported to the National Regulatory Authority.

Tris(β-diketonato)europium(III) complexes of general formula [Eu(TPI) 3 ·L], with chelating ligands such as 3-phenyl-4-(4-toluoyl)-5-isoxazolone (HTPI) and adduct-forming reagents [L = H 2 O, tri-n-octylphosphane oxide (TOPO), triphenylphosphane oxide (TPhPO), 1,10-phenanthroline], have been synthesized and characterized by elemental analysis and FT-IR, 1 H NMR, and photoluminescence spectroscopy. The coordination geometries of the complexes were calculated using the Sparkle/AM1 (Sparkle model for the calculation of lanthanide complexes within the Austin model 1) model. The ligand-Eu 3+ energy-transfer rates were calculated using a model of intramolecular energy transfer in lanthanide coordination complexes reported in the literature. The room-temperature PL spectra of the europium(III) complexes are com-

Purpose The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 1999 guidelines on contrast medium-induced nephropathy (CIN). Areas covered Topics reviewed include the definition of CIN, the choice of contrast medium, the prophylactic measures used to reduce the incidence of CIN, and the management of patients receiving metformin. Key Points • Definition, risk factors and prevention of contrast medium induced nephropathy are reviewed. • CIN risk is lower with intravenous than intra-arterial iodinated contrast medium.

It is shown that the paramagnetic properties of lanthanides can be exploited to obtain information on specific parts of a protein surface. Owing to the high affinity of coordinatively unsaturated lanthanide complexes for oxygen donors, carboxylate groups can be used as preferential targets for the interaction. The DO3A ligand is particularly useful in these studies, as it coordinates lanthanides in a heptadentate fashion, leaving two sites available for exogenous donors. A solution of a 15 N-labeled sample protein, calbindin D 9k (75 residues), was titrated with up to 200% of Gd(III)-DO3A complex, and an inversion recovery 15 N-1 H HSQC experiment was used to measure the paramagnetic contributions to the longitudinal relaxation rates of the amide protons. Relaxation data were used as distance constraints to estimate the number of interacting complexes and the occupancies of their binding sites. Four preferential interaction sites on the protein surface are found. Inspection of the various carboxylate side chains on the surface of the protein indicates that Gd(III)-DO3A interacts preferentially with carboxylaterich regions, rather than with isolated carboxylates, suggesting the possibility of chelation of one Gd(III)-DO3A molecule by two carboxylate groups. Gd(III)-DO3A is thus a valuable semi-selective probe for clusters of negative charges on the protein surface.

To facilitate future novel devices incorporating rare earth metal films and III-V semiconductors on Si substrates, this study investigates the mechanisms of growth via molecular beam epitaxy of gadolinium (Gd) on aluminum nitride (AlN) by determining the impact of substrate temperature on microstructure. The Gd films underwent extensive surface analysis via in situ reflective high energy electron diffraction (RHEED) and ex-situ SEM and AFM. Characterization of the surface features of rare earth metal films is important, as surface geometry has been shown to strongly impact magnetic properties. SEM and AFM imaging determined that Gd films grown on AlN (0001) from 80 °C to 400 °C transition from wetting, nodular films to island–trench growth mode to reduce in-plane lattice strain. XRD and Raman spectroscopy of the films revealed that they were primarily comprised of GdN, Gd and Gd2O3. The samples were also analyzed by a vibrating sample magnetometer (VSM) at room temperature. From the room temperature magnetic studies, the thick films showed superparamagnetic behavior, with samples grown between 240 °C and 270 °C showing high magnetic susceptibility. Increasing GdN (111) 2θ peak position and single-crystal growth modes correlated with increasing peak magnetization of the thin films, suggesting that lattice strain in single-crystal films was the primary driver of enhanced magnetic susceptibility.

The use of human stem cells (SCs) in tissue engineering holds promise in revolutionising the treatment of numerous diseases. There is a pressing need to comprehend the distribution, movement and role of SCs once implanted onto scaffolds. Nanotechnology has provided a platform to investigate this through the development of inorganic magnetic nanoparticles (MNPs). MNPs can be used to label and track SCs by magnetic resonance imaging (MRI) since this clinically available imaging modality has high spatial resolution. In this review, we highlight recent applications of iron oxide and gadolinium based MNPs in SC labelling and MRI; and offer novel considerations for their future development.

MR molecular imaging enables high-resolution, in vivo study of molecular processes frequently utilizing gadolinium-based probes that specifically bind to a particular biological molecule or tissue. While some MR probes are inactive when unbound and produce enhancement only after binding, the majority are less specific and cause enhancement in either state. Accumulation processes are then required to increase probe concentration in regions of the target molecule/tissue. Herein, a method is described for creating specificity for traditionally nonspecific probes. This method utilizes MR field-cycling methods to produce MRI contrast related to the dependence of R 1 upon magnetic field. It is shown that the partial derivative of R 1 with respect to magnetic field strength, R 1 , can be used as an unambiguous measure of probe binding. T 1-weighted images and R 1 images were produced for samples of albumin and buffer both enhanced with the albumin-binding agent Vasovist. For T 1 images, samples with low concentrations of Vasovist in an albumin solution could not be differentiated from samples with higher concentrations of Vasovist in buffer. Conversely, the R 1 images showed high specificity to albumin. Albumin samples with a 10-M concentration of Vasovist were enhanced over buffer samples containing up to 16 times more Vasovist. Magn Reson Med 61:796-802, 2009.

Hypertrophic pachymeningits is an unusual cause of neurological symptoms and is often secondary to infections, carcinomatosis or inflammatory diseases. It may also be idiopathic. We report a case of pachymeningitis which was manifested primarily by psychosis and visual loss with optic atrophy and destruction of nasal septum. The patient, a 45 year old woman was submitted to extensive investigation without evidence of any underlying disease. A meningeal biopsy was performed and showed a mostly unspecific inflammatory process with extensive fibrosis of the dura and few early stage granulomas. These findings suggest either neurosarcoidosis or idiopathic hypertrophic pachymeningitis.

Purpose: A characterization of a clinical unit for digital radiography (FUJIFILM FDR D-EVO) is presented. This system is based on the irradiation side sampling (ISS) technology and can be equipped with two different scintillators: one traditional gadolinium-oxysulphide phosphor (GOS) and a needle structured cesium iodide (CsI) phosphor panel.

This article reports the method of preparation of gadolinium oxide-doped silica nanoparticles (NPs) whose surface has been functionalized to anchor DNA onto it. The silica NP's surface was modified by 3-aminopropyltrimethoxysilane for DNA to bind electrostatically. Silica NPs with low polydispersity and encapsulating gadolinium oxide were prepared in the aqueous core of the reverse micelles. The average size of these spherical silica NPs doped with gadolinium oxide and dispersed in water is ∼ 50 nm as measured by dynamic light scattering and transmission electron microscopy. The plasmid DNA electrostatically held over NP's surface was firmly immobilized and protected from DNase attack. The gadolinium oxide-doped silica NPs are paramagnetic as observed from the nuclear magnetic resonance (NMR) line-broadening effect on proton spectrum of the surrounding water. In vitro transfection efficiencies of these gadolinium oxide-doped and DNA-conjugated silica NPs in COS-7 and 293T cells were found to be about 75% and 77% respectively of that of 'Polyfect®' as positive control. This article reports the method of preparation of gadolinium oxide-doped silica nanoparticles (NPs) whose surface has been functionalized to anchor DNA. These NPs are paramagnetic with in vitro transfection efficiencies in COS-7 and 293T cells of about 75% and 77% compared to 'Polyfect®' as positive control.

The increasing prevalence of adult congenital heart disease (CHD) can be attributed to major improvements in diagnosis and treatment of children with CHD. Although, echocardiography is the most commonly used imaging modality for diagnosis and follow up of subjects with CHD, the evolution of both cardiovascular magnetic resonance (MR) imaging and computed tomography (CT) does offer new ways to visualise the heart and great vessels. Cardiovascular MR techniques such as spin-echo and gradient-echo imaging, velocity-encoded phase-contrast MR and gadolinium-enhanced MR angiography allow comprehensive assessment of cardiac anatomy and function. This provides information about the long-term sequelae of the underlying anatomy, haemodynamic assessment of residual post-operative lesions and complications of surgery. Similarly, the development of spiral and subsequently multi-detector CT enables the acquisition of data during a single breath-hold and during the first pass of a contrast bolus, so that images can be reconstructed in any two-dimensional plane or in three-dimensions. As much of the functional data in CHD patients was traditionally acquired with invasive X-ray angiography, non-invasive alternatives such as cardiovascular MR and CT are desirable. This review evaluates the role of imaging modalities in the management of subjects with CHD, particularly detailing recent developments in imaging techniques as they relate to the various CHD diagnoses commonly encountered in practice. .au (R. Puranik).

In this study, we determined hemolysis activity in human and sheep erythrocytes, and characterized the electrical responses in Xenopus oocyte membrane elicited by the venom of the jelly®sh Cassiopea xamachana (Cx). The Cx venom produced hemolysis in both species, being more potent on human red cells. The electrophysiological study showed that the Cx venom elicited three different responses in the oocytes. One current was generated in all the oocytes tested and corresponded with a slow inward current (I Cx ) associated with an increase in membrane conductance. I Cx was concentration-dependent and had a reversal potential of 210.3^0.4 mV. Ionic substitution studies indicated that the conductive pathway was mainly permeable to cations and non-selective. The oocyte membrane resistance was completely recovered after washout of the venom, this suggested that the effect was due to generation of a speci®c membrane conductance as opposed to a possible non-speci®c membrane breakdown. A comparative study with three distinct native cationic channels present in the oocyte membrane [i.e. (1) hemi-gap-junction channels, (2) mechanosensitive channels, and (3) the ouabain-sensitive channel activated by palytoxin], showed that I Cx might correspond to opening of mechanosensitive channels or to activation of an unknown cationic channel located in the oocyte membrane. The bioactive fraction eliciting I Cx were peptides and was separated from two other peptidic hemolytic fractions by chromatography. q

Objective The aim of this study was to evaluate the range of techniques used by radiologists performing shoulder, hip, and knee arthrography using fluoroscopic guidance. Materials and methods Questionnaires on shoulder, hip, and knee arthrography were distributed to radiologists at a national radiology meeting. We enquired regarding years of experience, preferred approaches, needle gauge, gadolinium dilution, and volume injected. For each approach, the radiologist was asked their starting and end needle position based on a numbered and lettered grid superimposed on a radiograph. Results Sixty-eight questionnaires were returned. Sixtyeight radiologists performed shoulder and hip arthrography, and 65 performed knee arthrograms. Mean experience was 13.5 and 12.8 years, respectively. For magnetic resonance arthrography, a gadolinium dilution of 1/200 was used by 69-71%. For shoulder arthrography, an anterior approach was preferred by 65/68 (96%). The most common site of needle end position, for anterior and posterior approaches, was immediately lateral to the humeral cortex. A 22-gauge needle was used by 46/66 (70%). Mean injected volume was 12.7 ml (5-30). For hip arthrography, an anterior approach was preferred by 51/68 (75%). The most common site of needle end position, for anterior and lateral approaches, was along the lateral femoral head/neck junction. A 22-gauge needle was used by 53/68 (78%). Mean injected volume was 11.5 ml (5-20). For knee arthrography, a lateral approach was preferred by 41/64 (64%). The most common site of needle end position, for lateral and medial approaches, was mid-patellofemoral joint level. A 22-gauge needle was used by 36/65 (56%). Mean injected volume was 28.2 ml (5-60). Conclusion Arthrographic approaches for the shoulder, hip, and knee vary among radiologists over a wide range of experience levels.

ter verkrijging van de graad van doctor aan de Universiteit van Amsterdam op gezag van de Rector Magnificus prof. dr. J.W. Zwemmer ten overstaan van een door het college voor promoties ingestelde commissie, in het openbaar te verdedigen in de Aula der Universiteit op donderdag 1 maart 2007, te 12:00 uur door William Franciscus Agatha Klein Zeggelink geboren te Lichtenvoorde

Background-Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease characterized by a diverse clinical and phenotypic spectrum. This study reports the prevalence, morphology, clinical course, and management of an underrecognized subgroup of HCM patients with left ventricular apical aneurysms. Methods and Results-Of 1299 HCM patients, 28 (2%) were identified with left ventricular apical aneurysms, including a pair of identical twins. Aneurysms were recognized at a wide age range (26 to 83 years), including 12 patients (43%) who were Յ50 years of age. Apical aneurysms varied considerably in size (maximum dimension, 10 to 66 mm), were dyskinetic/akinetic with thin rims, and were associated with transmural (and often more extensive) myocardial scarring identified by late gadolinium enhancement cardiovascular magnetic resonance. Apical aneurysms were recognized by echocardiography in only 16 of 28 patients (57%) but by cardiovascular magnetic resonance in the 12 patients undetected by echocardiography. Left ventricular chamber morphology varied; however, 19 patients (68%) showed an "hourglass" contour, with midventricular hypertrophy producing muscular narrowing and intracavitary gradients in 9 patients (74Ϯ42 mm Hg). Sarcomeric protein missense mutations known to cause other phenotypic expressions of HCM were present in 3 patients. Over 4.1Ϯ3.7 years of follow-up, 12 patients (43%) with left ventricular apical aneurysms experienced adverse disease complications (event rate, 10.5%/y), including sudden death, appropriate implantable cardioverter-defibrillator discharges, nonfatal thromboembolic stroke, and progressive heart failure and death.

This case report describes the features of gadolinium-enhanced MRI in well-differentiated liposarcoma with histologic correlation and addresses the usefulness of this imaging technique in distinguishing well-differentiated liposarcoma from lipoma. Gadolinium-enhanced MRI revealed significantly enhanced signal in well-differentiated liposarcoma in a background of multiple welldifferentiated benign fatty masses by showing the increased vascularity in the septa of well-differentiated liposarcoma. Although such signal enhancement can be seen in some types of benign lipomatous tumors with increased blood vessels, this technique is helpful in selection of biopsy site, especially in a clinical setting of multiple fatty masses.

We have engineered Apolipoprotein A-I (apoA-I), a major protein constituent of high-density lipoprotein (HDL), to contain DOTA-chelated Gd(III) as an MRI contrast agent for the purpose of imaging reconstituted HDL (rHDL) biodistribution, metabolism, and regulation in vivo. This protein contrast agent was obtained by reacting the thiol-reactive Gd[MTS-ADO3A] label with Cys engineered at four distinct positions (52, 55, 76 and 80) in apoA-I. MRI of infused mice previously showed that the Gd-labeled apoA-I migrates to both the liver and the kidney, the organs responsible for HDL catabolism; however, the contrast properties of apoA-I are superior when the ADO3A moiety is located at position 55, compared to the protein labeled at positions 52, 76 or 80. It is shown here that continuous wave X-band (9 GHz) EPR spectroscopy is capable of detecting differences in the Gd(III) signal when comparing the labeled protein in the lipid-free to the rHDL state. Furthermore, the values of NMR relaxivity obtained for labeled variants in both the lipid-free and rHDL states correlate to the product of the X-band Gd(III) spectral width and the collision frequency between a nitroxide spin label and a polar relaxation agent. Consistent with its superior relaxivity measured by NMR, the rHDL-associated apoA-I containing the Gd[MTS-ADO3A] probe attached to position 55 displays favorable dynamic and water accessibility properties as determined by X-band EPR. While room temperature EPR requires >1 mM Gd(III)labeled and only >10 μM nitroxide-labeled protein to resolve the spectrum, the volume requirement is exceptionally low (~5μL). Thus, X-band EPR provides a practical assessment for the suitability of imaging candidates containing the site-directed ADO3A contrast probe.

Megavoltage portal images suffer from poor quality compared to those produced with kilovoltage x-rays. Several authors have shown that the image quality can be improved by modifying the linear accelerator to generate more low-energy photons. This work addresses the problem of using Monte Carlo simulation and experiment to optimize the beam and detector combination to maximize image quality for a given patient thickness. A simple model of the whole imaging chain was developed for investigation of the effect of the target parameters on the quality of the image. The optimum targets (6 mm thick aluminium and 1.6 mm copper) were installed in an Elekta SL25 accelerator. The first beam will be referred to as Al6 and the second as Cu1.6. A tissueequivalent contrast phantom was imaged with the 6 MV standard photon beam and the experimental beams with standard radiotherapy and mammography film/screen systems. The arrangement with a thin Al target/mammography system improved the contrast from 1.4 cm bone in 5 cm water to 19% compared with 2% for the standard arrangement of a thick, high-Z target/radiotherapy verification system. The linac/phantom/detector system was simulated with the BEAM/EGS4 Monte Carlo code. Contrast calculated from the predicted images was in good agreement with the experiment (to within 2.5%). The use of MC techniques to predict images accurately, taking into account the whole imaging system, is a powerful new method for portal imaging system design optimization.

A novel method of fabrication of gadolinia doped bismuth oxide nanoceramic via the sol gel technique is reported. Their thermal, structural and morphological properties are described by measurements of Differential Thermal Analysis/Thermal Gravimetry, X-ray Powder Diffraction and Scanning Electron Microscopy. The samples have stable high ion conductive face centered cubic delta-phase nanocrystalline structure. The electrical measurements of the nanoceramic powders were carried out in the temperature range of (689-1091 K) using 4-point probe technique. There is a transition between two distinct regions at 720 degrees C, which can be attributed to the order disorder transition. This observation is supported by the differential thermal analysis measurements. The experimental results show that the value of conductivity increases with increasing temperature over linear parts characterized by two different activation energies. The conductivity data over whole measured temperature range were fitted to the Arrhenius equations of conductivity and it shows two linear regions with different slopes which correspond to low-temperature range (689-975 K) and high-temperature range (999-1091 K). The values of E-a1 and E-a2 were obtained from the slopes of In or,c versus qlkT plot as 1.25 eV and 2.81 eV for low-temperature range and high-temperature range, respectively.

In patients with renal failure, iodinated contrast agents may cause acute deterioration of the renal function and gadolinium-based contrast agents (GBCAs) may cause nephrogenic systemic fibrosis (NSF). The administration of a contrast agent must thus be reviewed for each patient and evaluation of renal function is paramount even though its estimation using formulas derived from the creatinine level may fluctuate. For iodinated contrast agents, contrast induced nephropathy is reduced by hydratation, preferably intravenous, when the GFR is less than 60 ml/min. The risk for intravenous injections is less than the risk for arterial injections, and the GFR threshold may be reduced to 45 ml/min. For gadolinium-based contrast agents, patients at risk for NSF are those with end-stage renal disease and patients undergoing dialysis. In such cases, the injection of a gadolinium-based contrast agent is only considered after a risk-benefit analysis has been completed, an alternate linear or macr...

The strong increase in the consumption of rare earth elements (REE) in high-tech products and processes is accompanied by increasing amounts of REE released into the environment. Following the first report of Gd contamination of the hydrosphere in 1996, anthropogenic Gd originating from contrast agents has now been reported worldwide from river and estuarine waters, coastal seawater, groundwater and tap water. Recently, microcontamination with La, that is derived from a point source where catalysts for petroleum refining are produced, has been detected in the Rhine River in Germany and the Netherlands. Here we report the occurrence of yet another REE microcontamination of river water: in addition to anthropogenic Gd and La, the Rhine River now also shows significant amounts of anthropogenic Sm. The anthropogenic Sm, which enters the Rhine River north of Worms, Germany, with the same industrial wastewater that carries the anthropogenic La, can be traced through the Middle and Lower Rhine to the Netherlands. At Leverkusen, Germany, some 250 km downstream from the point source at Worms, anthropogenic Sm still contributes up to 87% of the total dissolved Sm concentration of the Rhine River. Results from ultrafiltration suggest that while the anthropogenic Gd is not particle-reactive and hence exclusively present in the truly dissolved REE pool (o10 kDa), the anthropogenic La and Sm are also present in the colloidal/nanoparticulate REE pool (between 10 kDa and 0.2 mm). Though difficult to quantify, our data suggest that the Rhine River may carry up to 5700 kg of anthropogenic La, up to 584 kg of anthropogenic Sm, and up to 730 kg of anthropogenic Gd per year toward the North Sea. There exist no regulatory limits for dissolved REE in natural waters, but total REE and Y (PREY) concentrations of up to 0.14 mg/kg in the plume downstream of and 52.2 mg/kg at the head of an effluent pipe at Rhine-km 447.3 at Worms get close to and well-above, respectively, the levels at which ecotoxicological effects have been documented. Because of the increasing use of REE and other formerly ‘‘exotic’’ trace elements in high-tech applications, these critical metals have now become emerging contaminants that should be monitored, and it appears that studies of their biogeochemical behavior in natural freshwaters might soon no longer be possible.

In this study, magnesia stabilized zirconia based nanocrystalline ceramics were produced through a polymer precursor route using gadolinium and boron. The powders were characterized during the various steps by structural and morphological techniques (FT-IR, XRD, and SEM). XRD results proved that a tetragonal phase is predominant for all samples with varying magnesium contents and no monoclinic zirconia solid solution appears. The crystallite sizes of the samples were calculated using Scherrer equation. The smallest crystallite size was obtained for the sample containing Zr/Mg/Ce/Gd/B ratio of 82/0/10/8/0. The lattice parameters were calculated for cubic, tetragonal, hexagonal, and orthorhombic structures. SEM results show all the samples have spherical grains. The average grain diameters were calculated for all the samples. The smallest average grain diameter was obtained for the sample containing Zr/Mg/Ce/Gd/B ratio of 82/0/10/8/0.