A comparative study of 1H NMR lineshape fitting analyses and biochemical lipid analyses of the lipoprotein fractions VLDL, LDL and HDL, and total human blood plasma.
ABSTRACT The purpose of this work was two-fold. In the first instance, 1H NMR spectra of the ultracentrifuged lipoprotein fractions (VLDL, LDL and HDL) from six volunteers with different clinical conditions were measured. The methylene regions of the experimental spectra were modelled in the frequency domain using non-linear lineshape fitting analyses. In this way the resolvable Lorentzian component structures of the methylene regions of these lipoprotein fraction spectra could be determined. Second, the lipoprotein fraction analyses were used to construct simplified component structures, which interpreted the lipoprotein fraction spectra well, and were feasible to use in the total plasma spectra analyses. The considerable overlap problem of the resonances was properly handled in this way. The NMR-based relative amounts of the lipoproteins (relative integrated intensities of the lipoprotein model signals) obtained were compared to the biochemically resolved relative molar percentages of the lipoprotein fractions and also of the lipid contents between the lipoprotein complexes. It was noticed that nearly all correlations were extremely good. Thus, it is suggested that the developed methodology could be used as a fast method to predict the relative amounts of the lipoproteins and also possibly the relative lipid contents between the major lipoprotein categories directly from the proton NMR spectrum of a total blood plasma sample. Furthermore, if internal or external reference for the integrated intensities of the proton NMR resonances were used, it should also be possible to obtain the absolute amounts of these quantities.
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ABSTRACT: We demonstrate that information on internal orientational order and size of lipoprotein particles can be extracted from the positions of their NMR spectral lines. The magnetic field obtained by solving the field equations for a model lipoprotein particle is shown to account for the hitherto unexplained size dependence of the experimental NMR frequencies. The predicted sign, magnitude, and functional form of the frequency shifts are verified by novel experimental 1H NMR data from size-specifc lipoprotein samples.Physical Review Letters 07/1994; 72(25):4049-4052. · 7.73 Impact Factor
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ABSTRACT: A comparison between a time domain analysis algorithm (VARPRO) and a frequency domain analysis algorithm (FITPLAC) for parameter estimation of magnetic resonance spectroscopy (MRS) data series is presented. VARPRO analyses the measured MRS signal (free induction decay; FID); FITPLAC analyses the discrete Fourier transform of the FID, the frequency domain magnetic resonance spectrum. A rapid time domain method, used to subtract the dominating water resonance from a 1H MRS FID, without affecting the metabolites of interest, is outlined and applied. Also a new "pseudofrequency selective" approach to time domain fitting is introduced. The possibilities of combining the most favorable features of time and frequency domain processing into one single MRS signal processing method are assessed. The 1H MRS signals of ultracentrifuged very low (VLDL), intermediate (IDL), and high (HDL) density lipoprotein fractions from human blood plasma were used for the comparisons. The results from both algorithms were in good agreement.Magnetic Resonance in Medicine 05/1994; 31(4):347-58. · 3.27 Impact Factor
- Progress in Nuclear Magnetic Resonance Spectroscopy 04/2013; 70:1-24. · 6.02 Impact Factor