Lim H M, Price T B, Marsh J C, Rainey P M, Gore J C, Armitage I M
Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06510.
Yale J Biol Med. 1991 Jan-Feb;64(1):63-77.
Selected factors have been evaluated in order to determine their influences on the plasma lipoprotein proton NMR spectra of normal and cancer patients. The variables were donor's diet (fasting/non-fasting), temperature and time of sample storage, processing procedure, centrifugation speed, and water pre-saturation time. Plasma samples from fasting individuals that were placed immediately on ice, spun at 1,000 and 3,000 g for 15 minutes, and the proton NMR spectrum acquired with the Carr-Purcell Meiboom-Gill (CPMG) pulse sequence, using a two-second water pre-saturation time, consistently gave reproducible results. Resonances attributed to lactate were minimized under these processing conditions. Centrifugation speed and pre-saturation time did not affect the average line width; however, donor fasting state, processing temperature, and storage time did alter the line width. Most important, blood chemistry analysis revealed an inverse correlation between triglyceride levels and average methyl and methylene line widths. Thus, these factors alone caution against the indiscriminate use of proton NMR spectra to differentiate plasma from normal and cancer patients.
为了确定某些因素对正常人和癌症患者血浆脂蛋白质子核磁共振谱的影响，对选定的因素进行了评估。这些变量包括供体的饮食（禁食/非禁食）、温度、样品储存时间、处理程序、离心速度和水预饱和时间。来自禁食个体的血浆样本立即置于冰上，以1000和3000克的离心力离心15分钟，并使用两秒的水预饱和时间，通过Carr-Purcell Meiboom-Gill（CPMG）脉冲序列采集质子核磁共振谱，始终能得到可重复的结果。在这些处理条件下，归因于乳酸的共振被最小化。离心速度和预饱和时间不影响平均线宽；然而，供体的禁食状态、处理温度和储存时间确实会改变线宽。最重要的是，血液化学分析显示甘油三酯水平与平均甲基和亚甲基线宽之间呈负相关。因此，仅这些因素就提醒人们不要不加区分地使用质子核磁共振谱来区分正常人和癌症患者的血浆。
