Estimation of the time since death.
ABSTRACT 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.
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ABSTRACT: An estimation of the post mortem interval (PMI) is frequently touted as the Holy Grail of forensic pathology. During the first hours after death, PMI estimation is dependent on the rate of physical observable modifications including algor, rigor and livor mortis. However, these assessment methods are still largely unreliable and inaccurate. Alternatively, RNA has been put forward as a valuable tool in forensic pathology, namely to identify body fluids, estimate the age of biological stains and to study the mechanism of death. Nevertheless, the attempts to find correlation between RNA degradation and PMI have been unsuccessful. The aim of this study was to characterize the RNA degradation in different post mortem tissues in order to develop a mathematical model that can be used as coadjuvant method for a more accurate PMI determination. For this purpose, we performed an eleven-hour kinetic analysis of total extracted RNA from murine's visceral and muscle tissues. The degradation profile of total RNA and the expression levels of several reference genes were analyzed by quantitative real-time PCR. A quantitative analysis of normalized transcript levels on the former tissues allowed the identification of four quadriceps muscle genes (Actb, Gapdh, Ppia and Srp72) that were found to significantly correlate with PMI. These results allowed us to develop a mathematical model with predictive value for estimation of the PMI (confidence interval of ±51 minutes at 95%) that can become an important complementary tool for traditional methods.PLoS ONE 01/2013; 8(2):e56507. · 3.73 Impact Factor
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ABSTRACT: Estimation of time since death is a paramount medico-legal issue in any postmortem examination. The present study is intended to study the correlation between postmortem interval and vitreous humor chemistry for sodium, potassium, and chlorides. The study is aimed to find male-female differences and differences between right and left eyes in vitreous chemistry. The vitreous humor samples were collected in 114 autopsies conducted in the study center and analyzed biochemically. All the cases where exact time of death was known and where the time since death ranged between 0 and 36 h were included in the study. Data obtained was analyzed statistically using spss version 11.0. The present research did not find a significant correlation between vitreous chemistry and postmortem interval. The differences in vitreous sodium, potassium, chloride levels and the sodium potassium ratio among males and females and between right and left eyes were not found to be statistically significant.Journal of forensic and legal medicine 05/2013; 20(4):211-6.
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ABSTRACT: Computed tomography (CT) in forensic medicine is commonly used in determination of cause of death. Here, we show that the information provided by CT may also be of value for estimation of time after death. The relationship between abdominal aorta narrowing just below the diaphragm and time after death was examined in 140 cases. Aorta narrowing was defined using a flatness ratio, which was calculated by dividing the shorter axis of the aorta by the longer axis. Time after death was classified into 6 time periods. The flatness ratio gradually and significantly decreased with increased postmortem time, showing increased aorta narrowing with increased time after death. A further examination of aorta narrowing in 15 autopsy cases in which CT images were taken at two postmortem times gave similar findings. The results of the study suggest that aorta narrowing in postmortem CT imaging may be used to estimate time after death.Journal of forensic and legal medicine 11/2013; 20(8):1075-7.