Department of Translational Physiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
Med Biol Eng Comput. 2010 Dec;48(12):1233-42. doi: 10.1007/s11517-010-0698-7. Epub 2010 Nov 3.
Although it is generally accepted that oxygen-quenched phosphorescence decay traces can be analyzed using the exponential series method (ESM), its application until now has been limited to a few (patho)physiological studies, probably because the reliability of the recovered oxygen tension (pO(2)) histograms has never been extensively evaluated and lacks documentation. The aim of this study was, therefore, to evaluate the use of the ESM to adequately determine pO(2) histograms from phosphorescence decay traces. For this purpose we simulated decay traces corresponding to uni- and bimodal pO(2) distributions and recovered the pO(2) histograms at different signal-to-noise ratios (SNRs). Ultimately, we recovered microvascular pO(2) histograms measured in the rat kidney in a model of endotoxemic shock and fluid resuscitation and showed that the mean microvascular oxygen tension, [Symbol: see text]pO(2)[Symbol: see text], decreased after induction of endotoxemia and that after 2 h of fluid resuscitation, [Symbol: see text]pO(2)[Symbol: see text] remained low, but the hypoxic peak that had arisen during endotoxemia was reduced. This finding illustrates the importance of recovering pO(2) histograms under (patho)physiological conditions. In conclusion, this study has characterized how noise affects the recovery of pO(2) histograms using the ESM and documented the reliability of the ESM for recovering both low- and high-pO(2) distributions for SNRs typically found in experiments. This study might therefore serve as a frame of reference for investigations focused on oxygen (re)distribution during health and disease and encourage researchers to (re-)analyze data obtained in (earlier) studies possibly revealing new insights into complex disease states and treatment strategies.
虽然人们普遍认为氧猝灭磷光衰减轨迹可以使用指数级数法（ESM）进行分析，但直到现在，它的应用仅限于少数（病理）生理学研究，这可能是因为恢复的氧张力（pO(2)）直方图的可靠性从未得到广泛评估并且缺乏文件记录。因此，本研究的目的是评估 ESM 用于从磷光衰减轨迹中充分确定 pO(2)直方图的用途。为此，我们模拟了对应于单峰和双峰 pO(2)分布的衰减轨迹，并在不同信噪比（SNR）下恢复了 pO(2)直方图。最终，我们恢复了内毒素休克和液体复苏模型中大鼠肾脏测量的微血管 pO(2)直方图，并表明平均微血管氧张力 [Symbol: see text]pO(2)[Symbol: see text] 在诱导内毒素血症后降低，并且在 2 小时的液体复苏后，[Symbol: see text]pO(2)[Symbol: see text] 仍然较低，但内毒素血症期间出现的缺氧峰已降低。这一发现说明了在（病理）生理条件下恢复 pO(2)直方图的重要性。总之，本研究使用 ESM 描述了噪声如何影响 pO(2)直方图的恢复，并记录了 ESM 恢复通常在实验中发现的 SNR 下的低 pO(2)和高 pO(2)分布的可靠性。因此，本研究可以作为参考框架，用于研究健康和疾病期间的氧气（再）分布，并鼓励研究人员重新分析可能揭示复杂疾病状态和治疗策略新见解的早期研究中获得的数据。
