Measuring glucose cerebral metabolism in the healthy mouse using hyperpolarized ¹³C magnetic resonance.

The mammalian brain relies primarily on glucose as a fuel to meet its high metabolic demand. Among the various techniques used to study cerebral metabolism, <sup>13</sup> C magnetic resonance spectroscopy (MRS) allows following the fate of <sup>13</sup> C-enriched substrates through metabolic pathways. We herein demonstrate that it is possible to measure cerebral glucose metabolism in vivo with sub-second time resolution using hyperpolarized <sup>13</sup> C MRS. In particular, the dynamic <sup>13</sup> C-labeling of pyruvate and lactate formed from <sup>13</sup> C-glucose was observed in real time. An ad-hoc synthesis to produce [2,3,4,6,6- <sup>2</sup> H <sub>5</sub> , 3,4- <sup>13</sup> C <sub>2</sub> ]-D-glucose was developed to improve the <sup>13</sup> C signal-to-noise ratio as compared to experiments performed following [U- <sup>2</sup> H <sub>7</sub> , U- <sup>13</sup> C]-D-glucose injections. The main advantage of only labeling C3 and C4 positions is the absence of <sup>13</sup> C- <sup>13</sup> C coupling in all downstream metabolic products after glucose is split into 3-carbon intermediates by aldolase. This unique method allows direct detection of glycolysis in vivo in the healthy brain in a noninvasive manner

Comparison of different methods for structural analysis of lanthanide-induced NMR shifts: a case of lanthanide(III) cryptates

The three main methods available in the literature for lanthanide-induced shift (LIS) structural analysis of a series of lanthanide(III) complexes in solution are applied to the data available for a complete series of paramagnetic lanthanide cryptate complexes of a Schiff base axial macrobicyclic ligand L, [LnL]3+. The macrobicycle contracts its cavity as a result of the lanthanide contraction, while preserving the same overall structure in solution. This causes breaks in the LIS plots for all the three methods used. A combined analysis of the data allows to conclude that those breaks reflect abrupt changes of the crystal field parameter A20 and the hyperfine constants Fi of the lanthanides in the middle of the series, but not of the structure of the complex in solution.http://www.sciencedirect.com/science/article/B6TWY-43BXWKG-8F/1/4616e022583602507b74136161dfff3

In vivo determination of human breast fat composition by 1H magnetic resonance spectroscopy at 7 T

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