Otvos J D, Jeyarajah E J, Hayes L W, Freedman D S, Janjan N A, Anderson T
Department of Chemistry, University of Wisconsin-Milwaukee.
Clin Chem. 1991 Mar;37(3):369-76.
We conducted a comprehensive investigation of the origin of nuclear magnetic resonance (NMR) lineshape variability of plasma lipids among healthy individuals and those with cancer. The methyl and methylene resonances of lipid in human plasma, whose linewidths have been reported to correlate with the presence of malignancy, are composed of the overlapping resonances of "mobile" protons from the major lipoproteins (very-low-, low-, and high-density lipoproteins). We tested two hypotheses for the origin of the narrower plasma linewidths observed for cancer patients: (a) malignancy-associated differences in the spectral properties (chemical shift, lineshape) of one or more of the lipoproteins, and (b) differences in the fraction of lipoprotein lipid giving rise to detectable NMR signal. Analysis of the concentrations of lipoprotein lipid and of 500 MHz NMR spectra of the lipoprotein constituents in greater than 100 plasma samples failed to provide support for either hypothesis. Although linewidths were found to be significantly narrower for the cancer group, the difference is entirely attributable to differences in the concentrations of the lipoproteins.
我们对健康个体和癌症患者血浆脂质的核磁共振（NMR）线形状变异性的起源进行了全面调查。据报道，人血浆中脂质的甲基和亚甲基共振的线宽与恶性肿瘤的存在相关，它们由主要脂蛋白（极低密度、低密度和高密度脂蛋白）中“流动”质子的重叠共振组成。我们对癌症患者血浆线宽较窄的起源测试了两种假设：（a）一种或多种脂蛋白的光谱特性（化学位移、线形状）与恶性肿瘤相关的差异，以及（b）产生可检测NMR信号的脂蛋白脂质部分的差异。对100多个血浆样本中脂蛋白脂质浓度和脂蛋白成分的500 MHz NMR光谱的分析未能为这两种假设提供支持。尽管发现癌症组的线宽明显更窄，但这种差异完全归因于脂蛋白浓度的差异。
