Microscopical study on estimation of time since death in skeletal remains

For the purpose of estimating time since death in skeletal remains, postmortem changes in human compact bones were examined by microradiography and electron microscopy. The UV-fluorescence of the peripheral zone of compact bone was also examined by microscopic spectrophotometry. Microradiographic examination revealed no morphological changes in bones left in the open air for long periods, except one of 15 years since death. In bones left in the soil, vacuoles of 5-10 microns diameter, which contained a honeycomb-like structure formed by small vacuoles of 0.5-1 microns diameter, were found in the peripheral zone of the substantia compacta approximately 5 years since death, and in bones of 6 years or more, this change extended to the mid-zone. In bones left in the sea for 4-5 years, vacuoles of 5-10 microns diameter were observed in the outer peripheral zone of the substantia compacta. The relative intensity of UV-fluorescence in bones dwindled with time since death and the correlation coefficient was considerably high.     

多体素~1H-MRS推断不同温度下死亡时间的研究

目的利用多体素质子磁共振波谱(1H-MRS)技术推断不同温度下的死亡时间。方法选取24只白兔,分为两组,利用多体素质子磁共振波谱测定死后30m in、1h、2h、4h、6h、8h、12h、16h、24h脑内N-乙酰天门冬氨酸、胆碱复合物、磷酸肌酸和肌酸各代谢物之间峰下面积的比值。结果死后24h内N-乙酰天门冬氨酸与磷酸肌酸和肌酸的比值随死亡时间的延长而降低,胆碱复合物与磷酸肌酸和肌酸的比值随死亡时间的延长而升高。Naa/Cr、Ch/Cr与PM I进行回归分析:自变量为Naa/Cr的二次多项式方程为:y=0.0020x2-0.0815x+1.4532(R2=0.971);自变量为Ch/Cr的二次多项式方程为:y=-0.0024x2+0.0870x+1.1876(R2=0.962)。用Naa/Cr的方程推测PM I,当PM I<24h时,平均偏离时间为1.70~50.27m in,用Ch/Cr的方程推测PM I,当PM I<24h时,平均偏离时间为1.12~98.11m in。结论Naa/Cr、Ch/Cr的死后变化与时间呈强相关性,可用于死亡时间推断。     

Practice of forensic entomology--usability of insect fragments in the estimation of the time of death

Forensic entomology analyzes and evaluates the presence of necrophagous or necrophilic insects on human corpses to estimate the post-mortem interval. The three cases presented are good examples illustrating that not only the various stages of development of the necrophagous insects from egg via larva to pupa are useful for forensic assessment. Depending on the situation in the individual case, even inconspicuous remains of past insect activity such as empty pupal cases or larval skins may supply important entomological information. For this purpose it is indispensable to preserve such evidence, which may appear only as fragments or pieces at first sight, for proper entomological assessment.     

单体素~1H-MRS推断死亡时间的初步研究

目的检测脑内N-乙酰天门冬氨酸、胆碱复合物及磷酸肌酸和肌酸的变化规律,并探讨其与死亡时间的关系。方法选取12只白兔,利用单体素氢质子磁共振波谱测定死后0.5、1、2、4、6、8、12、16、24h脑内N-乙酰天门冬氨酸、胆碱复合物及磷酸肌酸和肌酸峰下面积;分析其在上述时间点的变化规律,建立与死亡时间相关的回归方程。结果在死后24h内N-乙酰天门冬氨酸、磷酸肌酸和肌酸峰下面积随死亡时间的延长而降低(各时间点比较P<0.05),胆碱复合物在死后24h内无明显变化(各时间点比较P>0.05)。回归方程为:Naa:y=0.7425x2-27.282x+299.984(R2=0.962);Cr:y=0.3234x2-12.007x+210.503(R2=0.986)。结论死后24h内兔脑N-乙酰天门冬氨酸、磷酸肌酸和肌酸呈现出一定的变化规律,其与死亡时间相关程度较高,可用于对一定条件下死亡时间的推断。     

Strontium90 for determination of time since death

Strontium90 (Sr90) is an artificial nuclear fission product of the atmospheric a-bomb testing between 1945 and 1979. It was spread throughout the atmosphere in the following years. Sr90 is an analogue to calcium and therefore enriched in human bones. Several studies especially in the 1960s and 1970s were undertaken to investigate the Sr90 burden and the resulting incorporated radiation in humans, but present studies are missing. In this study nine bone samples, three from 1931/32 and six from 1989 to 1994 were examined by measuring the Sr90 radiation. The samples from 1931/32 did not show any Sr90 activity. All the samples from 1989 and later showed a Sr90 activity, but the intensity was very variable. Subsequent investigations should be done to determine the cut-off year for measurable Sr90 activity. Furthermore the determination of a specific time since death depending on Sr90 activity should be possible, due to the ranging Sr90 pollution between 1950 and 1980 and different uptake in adolescents and adults.     

The evolution of methods for estimating the time of death from body temperature

A chronological survey is offered of the development of concepts and techniques to use body temperature in the estimation of time since death. For a century and a half, this method has been investigated, though accuracy still cannot be claimed, especially in operational conditions.     

First practical applications of eye temperature measurements for estimation of the time of death in casework. Report of three cases

This paper presents first three successive cases of death where at scene measurements of the internal eyeball temperature soon after death allowed to precisely estimate the times of deaths based on this data (33.1°C, 32.2°C and 29.5°C, respectively), which were later confirmed during the police investigation. Simultaneously the rectal temperatures in all three cases were measured and appeared to be between 36.3 and 36.8°C-reflecting a living individual's body temperature. Thanks to a significantly faster postmortem decrease of the eye temperature and a residual or nonexistent plateau effect affecting the eye, using the formula developed in previous comprehensive studies in pigs, the time of death in real cases could be estimated with good precision: 1 h 33 min, 2 h 24 min and 3 h 17 min since death respectively. The actual TOD established during investigation appeared to be: between 1 h 30 min and 1 h 50 min in case 1; 1 h 55 min in case 2 and between 2 h 55 min and 3 h 05 min in case 3. Such precise estimation, mainly due to the plateau effect lasting up to a few hours, could not have been done based only on rectal temperature, commonly measured in forensic practice.     

脑温死亡时间测定仪的研制

目的研制脑温死亡时间测定仪。方法根据动物和尸体实验了解脑温下降的规律,并选择针状温度传感器,确定测温入径途径。结果针状传感器的优点是:快速敏感、准确性高、对组织破坏少、插入方便。尽管这种方法仍有误差,但它与现在法医学上常用的方法相比误差已减少了许多。结论所研制的死亡时间测定仪具有体积小,便于携带、探头灵敏,可以迅速方便地探测死者的脑温,并能直接推断死亡时间,避免了某些人为的因素造成的误差。     

The methodological aspects of establishing the time of death]

Methodological analysis of essence of problem concerning postmortem interval estimation is given. The authors present the most promising ways of scientific research on this problem and possibilities of practical use of results of scientific research. The general methods of postmortem interval estimation including wired-in analogy (criterial) method and methods of modelling postmortal processes (mathematical and physical) are analysed. Graph of logical structures of modes of postmortem interval estimation and means of their realization is given.     

Estimation of the time since death

The main principle of the determination of the time since death is the calculation of a measurable date along a time-dependent curve back to the start point. Characteristics of the curve (e.g. the slope) and the start point are influenced by internal and external, antemortem and postmortem conditions. These influencing factors have to be taken into consideration quantitatively in order to improve the precision of death time estimation. It does not make any sense to study the postmortem time course of any analyte without considering influencing factors and giving statistical parameters of the variability. Comparison of different methods requires an investigation of the same postmortem interval. For practical purposes, it must be concluded that the amount of literature on estimating the time since death has a reverse correlation with its importance in practice.     

A new biochemical method for estimation of postmortem time.

Hypoxanthine (Hx) is formed by hypoxic degradation of adenosine monophosphate (AMP) and might be elevated due to antemortem hypoxia. However, it also increases after cessation of the life processes. Until now measurements of potassium in corpus vitreous humor have been used by forensic pathologists to determine postmortem time. In this study the influence of postmortem time and temperature on vitreous humor Hx and potassium levels were compared. Repeated sampling of vitreous humor was performed in 87 subjects with known time of death and diagnosis. The bodies were kept at either 5 degrees C, 10 degrees C, 15 degrees C or 23 degrees C. Hx was measured by means of HPLC and potassium by flame photometry. In 19 subjects from whom samples were obtained within 1.5 h after death, the normal level of Hx could be estimated to be 7.6 mumol/l and that of potassium to be 5.8 mmol/l. The spread of the potassium levels measured shortly after death was much greater than for the corresponding Hx levels. In the four temperature groups the Hx level increased 4.2, 5.1, 6.2 and 8.8 mumol/l per h, respectively, whereas the corresponding figures for potassium were 0.17, 0.20, 0.25 and 0.30 mmol/l per h. The vitreous humor concentration of both Hx and potassium increases fairly linearly after death. The slopes are steeper with increasing temperature. Since the scatter of the levels is greater for potassium than for Hx, the latter parameter seems to be better suited for the determination of time of death in cases without antemortem hypoxia, especially during the first 24 h.     

多温度下死后心血pH值随时间变化的三维拟合函数研究

目的 探讨通过测量多温度条件下家兔右心血液pH值进行死亡时间推断的可行性.方法 48只家兔随机分为6组,空气栓塞法处死后于10℃、15℃、20℃、25℃、30℃和35℃的不同死亡时间点采集右心血液;用PB-10型pH仪测量样本pH值;SPSS统计软件进行回归分析;MATLAB软件进行数学分析.结果 各温度组右心血液pH值变化与死亡时间呈高度相关(R2=0.974 ～0.982);获得拟合的曲面方程.结论 利用插值函数拟合pH值与死亡时间的曲面方程可进行温度变化条件下的死亡时间推断.