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21.
Santarelli MF Positano V Giovannetti G Frijia F Menichetti L Ardenkjaer-Larsen JH De Marchi D Lionetti V Aquaro G Lombardi M Landini L 《NMR in biomedicine》2012,25(7):925-934
MRS of hyperpolarized (13) C-labeled compounds represents a promising technique for in vivo metabolic studies. However, robust quantification and metabolic modeling are still important areas of investigation. In particular, time and spatial resolution constraints may lead to the analysis of MRS signals with low signal-to-noise ratio (SNR). The relationship between SNR and the precision of quantitative analysis for the evaluation of the in vivo kinetic behavior of metabolites is unknown. In this article, this topic is addressed by Monte Carlo simulations, covering the problem of MRS signal model parameter estimation, with strong emphasis on the peak amplitude and kinetic model parameters. The results of Monte Carlo simulation were confirmed by in vivo experiments on medium-sized animals injected with hyperpolarized [1-(13) C]pyruvate. The results of this study may be useful for the establishment of experimental planning and for the optimization of kinetic model estimation as a function of the SNR value. 相似文献
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Gabriella Gobbi Tommaso Cassano Fatiha Radja Maria Grazia Morgese Vincenzo Cuomo Luca Santarelli René Hen Pierre Blier 《European neuropsychopharmacology》2007,17(5):328-338
The present studies examined the role of norepinephrine (NE) system in mediating the enhancement of 5-HT function produced by neurokinin (NK)1 receptor antagonism. Dorsal raphe 5-HT and locus coeruleus NE neurons were recorded in vivo in mice lacking NK1 receptors in wildtype mice pretreated with the NK1 antagonist RP67580 and its inactive enantiomer RP 68651. RP67580 and RP68651 were also tested on 5-HT neurons of mice lacking the 5-HT(1A) receptor. RP67580 increased the firing rate of 5-HT neurons in wildtype mice and in 5-HT(1A) null mutant mice to the same degree, thus indicating that the mechanism by which NK1 antagonists enhances 5-HT firing is independent of 5-HT(1A) receptors. NE neuronal burst activity was increased in NK1 null mutant and wildtype mice given RP67580, but not with RP68651. After NE depletion, RP67580 was ineffective in increasing 5-HT neuronal firing activity in NK1 wildtype mice, and the enhancement of 5-HT neuronal firing observed in NK1 null mutant mice was abolished. In conclusion, NE neurons are essential for the action of NK1 antagonists on 5-HT neurons. In addition, the desensitization of 5-HT(1A) autoreceptors produced by NK1 receptor antagonism is not critical for enhancing 5-HT neuronal firing. 相似文献
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Estelle Mounier-Geyssant Jean-François Barthélemy Lory Mouchot Christophe Paris Denis Zmirou-Navier 《BMC public health》2007,7(1):311
Background
This study describes exposure levels of bakery and pastry apprentices to flour dust, a known risk factor of occupational asthma. 相似文献26.
J Muller Y Giovangrandi D Cabrol M Uzan M Brauner J Santarelli C Sureau 《Revue fran?aise de gynécologie et d'obstétrique》1987,82(6):419-421
In reference to 4 severe cases of oligo-amnios of the second trimester of pregnancy, the authors advocate a method in order to improve the pre-natal diagnosis by intra-amniotic injection of a normal saline solution. This method facilitates the morphological exploration of the fetus by sonogram and enables to obtain a fetal karyotype by umbilical or amniotic tap. The potential risk of this technique are described. 相似文献
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Proton MR spectroscopy in quantitative in vivo determination of fat content in human liver steatosis
Renata Longo Piero Pollesello Claudio Ricci Flora Masutti Bjarne J. Kvam Luisa Bercich Lory S. Croce Piergiovanni Grigolato Sergio Paoletti Benedetto De Bernard Claudio Tiribelli Ludovico Dalla Palma 《Journal of magnetic resonance imaging : JMRI》1995,5(3):281-285
To demonstrate that the lipid volume fraction In liver steatosis can be accurately estimated with in vivo hydrogen-1 magnetic resonance (MR) spectroscopy, the authors developed a calibration procedure based on in vitro MR spectroscopy of lipid extracts from steatotlc liver specimens. The lipid volume fractions determined with the calibration procedure were compared with the results of histomorphometry and with calibrated computed tomographic (CT) data. The volume fraction of fat determined with MR spectroscopy was in good agreement with the CT results, whereas histomorphometry underestimated the amount of hepatic fat. The results indicate that determination of the fat volume fraction in steatotic liver can be achieved noninvasively with MR spectroscopy. 相似文献