11 documents found, page 1 of 2
Gold nanoparticles functionalised with fast water exchanging Gd3+ chelates: Lin...
Martins, J. A. R.; Ferreira, Paula M. T.; Geraldes, Carlos F. G. C.; Helm, Lothar; Prata, Maria I. M.; Rodrigues, Sérgio P. J.; Rodrigues, Tiago B.The relaxivity displayed by Gd3+ chelates immobilized onto gold nanoparticles is the result of complex interplay between nanoparticle size, water exchange rate and chelate structure. In this work we study the effect of the length of -thioalkyl linkers, anchoring fast water exchanging Gd3+ chelates onto gold nanoparticles, on the relaxivity of the immobilized chelates. Gold nanoparticles functionalized with Gd3...
Amide conjugates of the DO3A-N-(alpha-amino)propionate ligand: leads for stable...
Ferreira, Miguel Filipe Moreira Marques; Martins, André F.; Martins, Catarina I. O.; Ferreira, Paula M. T.; Tóth, Éva; Rodrigues, Tiago B.A novel synthetic methodology for preparing amide conjugates of the DO3A-N-(alfa-amino)propionate chelator is described, using the synthesis of the DO3A-N-(alfa-benzoylamido)propionate chelator as an illustrative example. The model Gd(DO3A-N-(alfa-benzoylamido)propionate) chelate displays accelerated water exchange, stability in a wide pH range and inertness towards transmetallation by Zn2+. The Gd(DO3A-N-(alaf...
Gd(III)-EPTPAC16, a new self-assembling potential liver MRI contrast agent: in ...
Torres, Suzana; Prata, Maria I. M.; Santos, Ana C.; André, João P.; Martins, José A.; Helm, Lothar; Tóth, Éva; García-Martín, Maria L.The recently reported amphiphilic chelate, [Gd(EPTPAC16)(H2O)]2-, forms supramolecular aggregates in aqueous solution by self-assembly of the monomers with a relaxometrically determined critical micellar concentration (CMC) of 0.34 mM. The effect of sonication on the aggregate size was characterized by dynamic light scattering and relaxometry, indicating the presence of premicellar aggregates and an overall dec...
A method to measure lactate recycling in cultured cells by edited 1H nuclear ma...
Rodrigues, Tiago B.; Cerdán, Sebastián; García-Martín, Maria L.http://www.sciencedirect.com/science/article/B6W9V-4PF6B5M-1/1/385b6c0836057ee00a92ea234317f1e6
A fast and sensitive 1H NMR method to measure the turnover of the H2 hydrogen o...
Rodrigues, Tiago B.; Cerdán, SebastiánA fast and sensitive procedure to determine the turnover of the H2 hydrogen of lactate and quantify its 2H-enrichment by 1H NMR is illustrated using C6 cells metabolizing (3-13C) lactate in 50% 2H2O (vol/vol). 2H substitution of the lactate H2 hydrogen resulted in two easily detectable transformations of the vicinal H3 doublet resonance: 1) the formation of an H3 singlet due to the disappearance of the homonucl...
Futile cycling of lactate through the plasma membrane of C6 glioma cells as det...
Rodrigues, Tiago B.; Gray, Heather L.; Benito, Marina; Garrido, Susana; Sierra, Alejandra; Geraldes, Carlos F.; Ballesteros, Paloma; Cerdán, SebastiánWe report a novel (13C, 2H) nuclear magnetic resonance (NMR) procedure to investigate lactate recycling through the monocarboxylate transporter of the plasma membrane of cells in culture. C6 glioma cells were incubated with [3-13C]lactate in Krebs-Henseleit Buffer containing 50% 2H2O (vol/vol) for up to 30 hr. 13C NMR analysis of aliquots progressively taken from the medium, showed: (1) a linearly decreasing si...
13C MRS: An outstanding tool for metabolic studies
Rodrigues, Tiago B.; Cerdán, SebastiánWe provide an overview of 13C magnetic resonance spectroscopy methods and their applications as an established metabolic tool with an emphasis on the use of high-resolution 13C magnetic resonance spectroscopy and 13C isotopomer analysis. Topics addressed include general properties of the 13C magnetic resonance spectroscopy spectrum; different 13C magnetic resonance spectroscopy acquisition protocols; determinat...
A (13)C isotopomer kinetic analysis of cardiac metabolism: influence of altered...
Carvalho, Rui A.; Rodrigues, Tiago B.; Zhao, Piyu; Jeffrey, F. Mark H.; Malloy, Craig R.; Sherry, A. DeanRat hearts were perfused with mixtures of [3-(13)C]pyruvate and [3-(13)C]lactate (to alter cytosolic redox) at low (0.5 mM) or high (2.5 mM) Ca(2+) concentrations to alter contractility. Hearts were frozen at various times after exposure to these substrates, were extracted, and were then analyzed by (13)C NMR spectroscopy. The time-dependent multiplets observed in the (13)C NMR resonances of glutamate in all he...
Sources of glucose production in cirrhosis by 2H2O ingestion and 2H NMR analysi...
Perdigoto, Rui; Furtado, Alexandre L.; Porto, Armando; Rodrigues, Tiago B.; Geraldes, Carlos F. G. C.; Jones, John G.Plasma glucose 2H enrichment was quantified by 2H NMR in patients with cirrhosis (n=6) and healthy subjects (n=5) fasted for 16 h and given 2H2O to ~0.5% body water. The percent contribution of glycogenolysis and gluconeogenesis to glucose production (GP) was estimated from the relative enrichments of hydrogen 5 and hydrogen 2 of plasma glucose. Fasting plasma glucose levels were normal in both groups (87±7 an...
Integration of [U-13C]glucose and 2H2O for quantification of hepatic glucose pr...
Perdigoto, Rui; Rodrigues, Tiago B.; Furtado, Alexandre L.; Porto, Armando; Geraldes, Carlos F. G. C.; Jones, John G.Glucose metabolism in five healthy subjects fasted for 16 h was measured with a combination of [U-13C]glucose and 2H2O tracers. Phenylbutyric acid was also provided to sample hepatic glutamine for the presence of 13C-isotopomers derived from the incorporation of [U-13C]glucose products into the hepatic Krebs cycle. Glucose production (GP) was quantified by 13C NMR analysis of the monoacetone derivative of plasm...