法医学杂志 ›› 2022, Vol. 38 ›› Issue (1): 59-66.DOI: 10.12116/j.issn.1004-5619.2021.410613

所属专题: 水中尸体研究专题

• 论著 • 上一篇    下一篇

基于玻璃体液代谢物的水中大鼠淹没时间推断

张富源1,2(), 王林林1,2,3, 张淼1,2,3, 董雯雯1,2,3, 张忠铎1,2, 李新杰1,2, 马星宇1,2, 杜书奎1,2, 袁浩淼1,2, 官大威1,2,3(), 赵锐1,2,3()   

  1. 1.中国医科大学法医学院 法医司法鉴定中心,辽宁 沈阳 110122
    2.智慧司法鉴定联合实验室,辽宁 沈阳 110122
    3.辽宁省法医学生物证据重点实验室,辽宁 沈阳 110122
  • 收稿日期:2021-06-21 出版日期:2022-02-25 发布日期:2022-06-21
  • 通讯作者: 官大威,赵锐
  • 作者简介:官大威,男,博士,教授,博士研究生导师,主要从事法医病理学教学、科研和司法鉴定;E-mail:dwguan@cmu.edu.cn
    赵锐,男,博士,教授,博士研究生导师,主要从事法医病理学教学、科研和司法鉴定;E-mail:rzhao@cmu.edu.cn
    张富源(1995—),男,博士研究生,主要从事法医病理学研究;E-mail:137667006@qq.com
  • 基金资助:
    国家重点研发计划资助项目(2018YFC0807204);国家自然科学基金资助项目(81801874);沈阳市中青年科技创新人才支持计划资助项目(RC200412)

Inferring Postmortem Submersion Interval in Rats Found in Water Based on Vitreous Humor Metabolites

Fu-yuan ZHANG1,2(), Lin-lin WANG1,2,3, Miao ZHANG1,2,3, Wen-wen DONG1,2,3, Zhong-duo ZHANG1,2, Xin-jie LI1,2, Xing-yu MA1,2, Shu-kui DU1,2, Hao-miao YUAN1,2, Da-wei GUAN1,2,3(), Rui ZHAO1,2,3()   

  1. 1.Center of Medico-legal Investigation, School of Forensic Medicine, China Medical University, Shenyang 110122, China
    2.Collaborative Laboratory of Intelligentized Forensic Science, Shenyang 110122, China
    3.Liaoning Province Key Laboratory of Forensic Bio-evidence Science, Shenyang 110122, China
  • Received:2021-06-21 Online:2022-02-25 Published:2022-06-21
  • Contact: Da-wei GUAN,Rui ZHAO

摘要: 目的

采用LC-MS/MS代谢组学技术结合数据分析,检测水中大鼠尸体死后早期玻璃体液中代谢谱变化及差异,探讨其用于早期死后淹没时间(postmortem submersion interval,PMSI)和死亡原因推断的可行性。

方法

于自然湖水中造模,将100只SD大鼠随机分为溺死组(50只)和死后[二氧化碳(CO2)窒息]即刻入水组(50只),分别于死后0、6、12、18及24 h从每组中取10只大鼠提取玻璃体液进行代谢组学检测,其中8只构建训练集模型、2只作为测试集样本。通过PCA及PLS多元统计分析探索训练集样本中不同PMSI及死因间的代谢谱差异,进而应用随机森林(random forest,RF)算法筛选生物标志物并以此构建模型。

结果

PCA及PLS分析可观察到玻璃体液代谢谱变化具有时间规律性,但不同死因间未发现明显差异。应用RF算法最终筛选到13种时间相关性较好的小分子生物标志物,基于该指标集构建了简化PMSI推断模型,测试数据表明模型预测的平均绝对误差为0.847 h。

结论

水中大鼠尸体玻璃体液中筛选出的13种代谢标志物与早期死后淹没时间具有良好的时间相关性,应用RF构建的简化PMSI推断模型可用于PMSI的推断。此外,玻璃体液代谢物不能用于早期水中尸体的死因鉴别。

关键词: 法医病理学, 代谢组学, 死后淹没时间, 玻璃体液, 液相色谱-串联质谱, 主成分分析, 偏最小二乘法, 大鼠

Abstract: Objective

The metabolomics technique of LC-MS/MS combined with data analysis was used to detect changes and differences in metabolic profiles in the vitreous humor of early rat carcasses found in water, and to explore the feasibility of its use for early postmortem submersion interval (PMSI) estimation and the cause of death determination.

Methods

The experimental model was established in natural lake water with 100 SD rats were randomly divided into a drowning group (n=50) and a postmortem (CO2 suffocation) immediately submersion group (n=50). Vitreous humor was extracted from 10 rats in each group at 0, 6, 12, 18 and 24 h postmortem for metabolomics analyses, of which 8 were used as the training set to build the model, and 2 were used as test set. PCA and PLS multivariate statistical analysis were performed to explore the differences in metabolic profiles among PMSI and causes of death in the training set samples. Then random forest (RF) algorithm was used to screen several biomarkers to establish a model.

Results

PCA and PLS analysis showed that the metabolic profiles had time regularity, but no differences were found among different causes of death. Thirteen small molecule biomarkers with good temporal correlation were selected by RF algorithm. A simple PMSI estimation model was constructed based on this indicator set, and the data of the test samples showed the mean absolute error (MAE) of the model was 0.847 h.

Conclusion

The 13 metabolic markers screened in the vitreous humor of rat corpses in water had good correlations with the early PMSI. The simplified PMSI estimation model constructed by RF can be used to estimate the PMSI. Additionally, the metabolic profiles of vitreous humor cannot be used for early identification of cause of death in water carcasses.

Key words: forensic pathology, metabolomics, postmortem submersion interval, vitreous humor, liquid chromatography-tandem mass spectrometry, principal components analysis, partial least square, rats

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