Measurement of Postmortem Pupil Size: A New Method with Excellent Reliability and Its Application to Pupil Changes in the Early Postmortem Period

Measurement of postmortem pupil width is a potential component of death time estimation. However, no standardized measurement method has been described. We analyzed a total of 71 digital images for pupil–iris ratio using the software ImageJ. Images were analyzed three times by four different examiners. In addition, serial images from 10 cases were taken between 2 and 50 h postmortem to detect spontaneous pupil changes. Intra‐ and inter‐rater reliability of the method was excellent (ICC > 0.95). The method is observer independent and yields consistent results, and images can be digitally stored and re‐evaluated. The method seems highly eligible for forensic and scientific purposes. While statistical analysis of spontaneous pupil changes revealed a significant polynomial of quartic degree for postmortem time (p = 0.001), an obvious pattern was not detected. These results do not indicate suitability of spontaneous pupil changes for forensic death time estimation, as formerly suggested.     

A Rare Case of Poisoning with a Volatile Substance: Quantitative Determination of n‐Butane in Postmortem Tissue

Poisoning with volatile substances remains exceptional. Authors report the case of a married couple who were found in a car with a butane gas bottle: the woman was dead and her husband alleged it was an unsuccessful suicide pact. A specific research of volatile substances on postmortem samples with headspace gas chromatography–mass spectrometry following a quantitative determination was performed. The n‐butane concentrations detected were composed of 610 μg/L (cardiac blood), 50 μg/kg (brain), 134 μg/kg (lungs), 285 μg/kg (liver), and 4090 μg/kg (heart) and were compatible with the rare lethal concentrations evoked in the literature. The cause of death was determined to be asphyxiation through n‐butane criminal poisoning. Authors recommendation therefore is to take samples immediately and place them in properly sealed containers and hence analyzing the samples as soon as possible after collecting them or storing them under ?30°C (?22°F) if analyses cannot be performed immediately.     

LIFE BEYOND LIFE – An Easy Way to Derive Lung Fibroblasts from Cadavers

Several protocols have illustrated the possibility of deriving cells, such as fibroblasts, from different organs. These techniques generally concern organs sampled from living persons, but have already been described for cadavers, especially concerning the skin and tendons. We present, for the first time, an easy way to derive pulmonary fibroblasts from a lung tissue sampled from a cadaver and directly culture plated. The fibroblast output was checked daily. We obtained lung fibroblasts from 3 (60%) cadavers and 2 (100%) living persons. The fibroblast output took about 3 days for cells from living persons and took up to 39 days for those from cadavers. We did not clearly identify any parameters that could explain these differences. Nevertheless, these derived cells had the same features as the source cells, especially in terms of morphology and proliferation, and could potentially be used in different research domains such as forensic or regeneration medicine.     

Determination of Time since Death using Vitreous Humor Tryptophan

Determination of time since death (TSD) plays very important role in forensic examination as it narrows down field of suspects and aids in deceased identification. This study utilizes the fluorescence property of vitreous humor (VH) tryptophan to determine TSD using o‐phthalaldehyde (OPA). The detection limit of these fluorometric studies was found to be 8 ppb indicating sensitivity and high accuracy in TSD determination. The study was performed on selected 76 cadaver with known TSD ranging from 3 to 90 h. Excellent correlation between VH tryptophan and TSD was obtained with a coefficient of correlation R² = 0.9590. Results showed statistically significant increase in vitreous tryptophan with TSD up to 90 h, and the proposed method was efficaciously applied for prediction of TSD as no systematic error exist. The regression equation obtained from the study is [Trp] = 2.21 + 2.98 * TSD.     

Use of Cardiac Injury Markers in the Postmortem Diagnosis of Sudden Cardiac Death

In the daily practice of forensic pathology, sudden cardiac death (SCD) is a diagnostic challenge. Our aim was to determine the usefulness of blood biomarkers [creatine kinase CK‐MB, myoglobin, troponins I and T (cTn‐I and T), and lactate dehydrogenase] measured by immunoassay technique, in the postmortem diagnosis of SCD. Two groups were compared, 20 corpses with SCD and 8 controls. Statistical significance was determined by variance analysis procedures, with a post hoc Tukey multiple range test for comparison of means (p < 0.05). SCD cases showed significantly higher levels (p < 0.05) of cTn‐T and cTn‐I compared to the control group. Although only cases within the first 8 h of postmortem interval were included, and the control group consisted mainly of violent death cases, our results suggest that blood troponin levels may be useful to support a diagnosis of SCD.     

不同温度下兔玻璃体液K~+浓度与死亡时间的关系研究

目的探索在不同环境温度条件下,玻璃体液中钾离子浓度变化规律与死亡时间的关系。方法家兔处死后分别置于5℃、15℃、25℃和35℃温度下保存,在0~120h内每12h双眼交替微量提取玻璃体液80~100μL;应用罗氏DPPI生化分析仪检测玻璃体液中K~+的浓度;应用插值函数进行分析拟合,建立死亡时间推断方程。结果各温度组家兔玻璃体液中K~+浓度随死亡时间延长均呈上升趋势,对所得数据进行插值拟合,在5℃~35℃的温度变化区间内,K~+浓度变化与PMI关系的三元五次曲面方程:f(x,y)=-1.998e~(14)+1.345e~(12)x+5.902e~(13)y+0.005 585x~2-4.509e~(11)xy-3.876e~(12)y~2-0.000 286 8x~3+0.003 545x~2y+4.406e~(10)xy~2-1.746e~(10)y~3+2.669e~(-6)x~4-1.568e~(-5)x~3y-0.000 177 1x~2y~2-1.64e~9xy~3+6.669e~9y~4-8.672e~(-9)x~5+4.467e~(-8)x~4y+2.354e~(-7)x~3y~2+2.459e~(-6)x~2y~3+2.05e~7xy~4-1.214e~8y~5(R~2=0.995 6),其中温度为自变量x,K~+浓度值为自变量y,PMI为因变量f(x,y)。结论在5℃~35℃的环境温度区间内,家兔眼玻璃体液中K~+浓度变化与死亡时间关系符合三元五次方程分布,利用插值函数拟合的方法可将环境温度作为参数,实现在环境温度变化条件下进行死亡时间推断。     

磁珠直接吸附法对体态检材游离DNA的提取

目的采用磁珠直接吸附法对人体尿液、唾液、血液3种体态生物检材中的游离DNA进行提取检验,为法医物证中游离DNA的研究及检验工作提供参考。方法对3种生物检材采取离心吸取上清液的方法分离游离DNA,然后采用磁珠直接吸附法进行提取纯化,Identifiler-Plus试剂盒进行复合扩增后常规STR检测。结果在3种检材中均检出了游离DNA,其中血液中游离DNA检出率为100%,唾液为90%,尿液为70%。结论人体体态生物检材中存在游离DNA,同时磁珠直接吸附法可高效、快捷的提取生物检材中的游离DNA。     

The relationship of methanol and formate concentrations in fatalities where methanol is detected

An automated headspace gas chromatography method was developed for the determination of formate (formic acid) in postmortem specimens, based on the in situ sulfuric acid-methanol methylation of formic acid to methyl formate. Diisopropyl ether was used as an internal standard. The method was applied to over 150 postmortem cases where methanol was detected. Of the 153 cases presented, 107 deaths were attributed to acute methanol toxicity. In the vast majority of the remaining 46 deaths, the methanol was determined to be present as a postmortem or perimortem artifact, or was otherwise incidental to the cause of death. Of the 76 victims who were found dead and blood was collected by the medical examiner, all but one had a postmortem blood formate concentration greater than 0.50 g/L (mean 0.85 g/L; n = 74). The sole exception involved suicidal ingestion of methanol where the blood methanol concentration was 7.9 g/L (790 mg/100 mL) and blood formate 0.12 g/L. In 97% (72/74) of the cases where blood was available, the blood formate was between 0.60 and 1.40 g/L. In 31 of the 153 cases, the victim was hospitalized and blood obtained on admission or soon after was analyzed for methanol and formate during the subsequent death investigation; the vast majority (27/30) had antemortem blood formate concentrations greater than 0.50 g/L. Cases with samples taken prior to death with blood formate concentrations less than 0.5 g/L can readily be explained by active treatment such as dialysis. The blood formate method has also been useful in confirming probable perimortem or postmortem contamination of one of more fluids or tissues with methanol (e.g., windshield washer fluid or embalming fluid), where methanol ingestion was unlikely.