[Contents of vitreous humor of dead body with different postmortem intervals].
OBJECTIVE
To establish regression correlations between postmortem interval (PMI) and contents of human vitreous humor of dead bodies for forensic purposes.


METHODS
The human vitreous humor were taken from 126 dead bodies between 0.5 to 216 hours after death, and 11 chemical elements were detected by the OLYMPUS AU400 auto-biochemistry instrument.


RESULTS
(1) The glucose, natrium and chlorine in human vitreous humor decreased, while the urea, creatinine, uric acid, potassium, calcium, magnesium, phosphorus, and micro-protein increased after death. The change of glucose, potassium and phosphorus were well correlated with the PMI (r = 0.824, 0.967, 0.880). But the uric acid and micro-protein did not have a good correlation with the PMI(r = 0.350, 0.153). (2) The stepwise regression analysis established the following equations for the PMI (Y): Y = -35. 15+6.05X, R2 = 0.957 (X = potassium); Y = -27.83+ 5.49X(1) - 1.35X(2), R2 = 0.960 (X(1) = potassium, X(2) = glucose); Y = -6.37+3.93X(1) -2.29X(2) + 5.36X(3), R2 = 0.966 (X(1) = potassium, X(2) = glucose, X(3) = phosphorus).


CONCLUSIONS
(1) Eleven chemical components in human vitreous humor change after death, among which postassium has the best linear correlation with the PMI within 72 hours after death. (2) The accuracy of the estimation of PMI could be improved by establishing a multi-variable equation through stepwise regression.
Tao
Tao
T
Department of Forensic Pathology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China.
Xu
Jing
J
Luo
Tong-Xing
TX
Liao
Zhi-Gang
ZG
Pan
Hong-Fu
HF
D003643:Death; D005260:Female; D005554:Forensic Medicine / Q000379:methods*; D006801:Humans; D008297:Male; D011180:Postmortem Changes; D012044:Regression Analysis; D013997:Time Factors; D014822:Vitreous Body / Q000378:metabolism*