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ABSTRACT: To prospectively investigate and detect early cerebral metabolic changes in patients with end-stage renal disease (ESRD) by using in vivo proton MR spectroscopy (MRS).
We enrolled 32 patients with ESRD and 32 healthy controls between the ages of 26 and 50 years. Short echo time single-voxel proton MRS was acquired from volumes of interest (VOIs) located in the frontal grey and white matter, temporal white matter and basal ganglia. The choline/phospatidylcholine (Cho), myo-inositol (mI), N-acetylaspartate (NAA) and total creatine (tCr) peaks were measured and the metabolic ratios with respect to tCr were calculated.
In the ESRD group, significant elevations of the Cho/tCr and mI/tCr ratios were observed for the frontal grey matter, frontal white matter, temporal white matter and basal ganglia as compared with controls. There was no significant difference in the NAA/tCr ratios at all VOIs between the ESRD patients and the healthy controls.
Proton MRS is a useful and non-invasive imaging tool for the detection of early cerebral metabolic changes in neurologically presymptomatic ESRD patients.
European Radiology 12/2009; 20(6):1502-7. · 3.22 Impact Factor
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The Annals of thoracic surgery 07/2006; 81(6):e31. · 3.74 Impact Factor
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ABSTRACT: The new complex of Gd(III) with the 1,7-bis[(N-dimethyl(carbomoyl)methyl)-1,4,7-triazaheptane-1,4,7- triacetate[Gd(DTPA-BDMA)] is a non-ionic paramagnetic complex designed for use as an extracellular magnetic resonance imaging (MRI) contrast agent. The R1 relaxivity value of [Gd(DTPA-BDMA)] is 4.13 +/- 0.2 mM-1S-1, which is similar to that of [Gd(DTPA)]2- (4.08 mM-1S-1). The purpose of this study is to examine the acute toxicity and MRI characteristics of [Gd(DTPA-BDMA)]. Our results show that the lethal dose (LD50) of the [Gd (DTPA-BDMA)] is 10.58 mmol/kg in ICR mice, which is higher than that of [Gd (DTPA)]-2-(6.40 mmol/kg). The MR images demonstrate that the enhancing effect and renal clearance of [Gd(DTPA-BDMA)] are similar to that of [Gd(DTPA)]2- either in control group or CHA (Cheng hepatoma ascites) tumor model in Wistar rats (p > 0.05). These findings indicate that [(DTPA-BDMA)] has similar characteristics of [Gd(DTPA)]2- and has the potential of becoming a safe and reliable magnetopharmaceutical for the extracellular MRI contrast agent.
The Kaohsiung journal of medical sciences 03/2002; 18(2):77-83. · 0.61 Impact Factor
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Journal of The Chemical Society-dalton Transactions - J CHEM SOC DALTON TRANS. 01/1997;
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ABSTRACT: A new bis(amide) derivative of diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid (H5dtpa), diethylenetriamine-N,N′,N″-triacetic-N,N″-bis(2-methoxyphenethylamide) (H3L), has been synthesized. The crystal structure of gadolinium(III) complex of H3L ([GdL]) has been determined by X-ray crystallography. The coordination sphere of Gd(III) comprises three amine nitrogens, two amide oxygens, three carboxylic acid oxygens, and one water molecule. 17O NMR shifts showed that the [DyL] complex had one inner-sphere water molecule. Relaxivity studies with the gadolinium(III) complex showed that they associate strongly with proteins leading to a significant relaxivity enhancement.
Polyhedron 18:1147-1152. · 2.06 Impact Factor
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ABSTRACT: Three bis(amide) derivatives of Hsdtpa [(carboxymethyl)iminobis(ethylenenitrilo)tetraacetic acid], H3L1 = bis(adamantanamide), H3L2 = bis(2-methoxybenzylamide), and H3L3 = bis(2-methoxyphenethylamide) were synthesized. Their protonation constants were determined by potentiometric titration in 0.10 mol dm−3 KCl and by NMR pH titration at 25.0±0.1°C. Stability and selectivity constants are measured to evaluate the possibility of using the corresponding gadolinium(III) complexes for magnetic resonance imaging contrast agents. Low stability or selectivity constants indicate higher possibility for releasing free Gd3+ ion and free ligand as well from gadolinium(III) complexes. The formations of gadolinium(III), copper(II), zinc(II), and calcium(II) complexes were investigated quantitatively by the potentiometry. The stability constant for gadolinium(III) complex is larger than those for Ca(II), Zn(II), and Cu(II) complexes for these three octadentate ligands. The selectivity constants and modified selectivity constants of the amides for Gd3+ over endogenously available metal ions were calculated. Effectiveness of all three ligands in binding divalent and trivalent metal ions in biological media is assessed by comparing pM values at physiological pH 7.4. Spinlattice relaxivity R1 for Gd(III) complexes was also determined. The observed relaxivity were found to decrease with increasing pH in the acid range below pH 3 and relaxivity values were become invariant with respect to pH changes over the range of 3–10.
Polyhedron 17:2021-2028. · 2.06 Impact Factor
