• Biomedical Science Letters
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• v.24 no.1
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• pp.35-42
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• 2018

Postmortem interval (PMI) is very important in the crime scene investigation. However, it is very difficult to estimate of the interval since death after a decomposition. Recently, there have been various studies on the postmortem interval since a decomposition. In particular, the total body score (TBS) and accumulated degree days (ADD) used to estimate the postmortem interval after a decomposition. This study was conducted with the aim of applying the TBS and ADD to estimate the postmortem interval in real forensic caseworks. In first murder case, TBS was 12 and ADD value was 132, respectively. An estimated time of PMI was around 23:00 on June 21, and the suspect's statement was 01:20 on June 22. Our estimated interval since death and the suspect's statement for the PMI differ by only 2 hours and 20 minutes. In second forensic case, TBS was 3 and ADD value was 55, respectively, an estimated time of PMI was around 02:26 on September 23. The suspect's statement was 10:30 on September 23. Our estimated time and the suspect's statement for the PMI differ by 8 hours. In these cases, we were able to have confirmed the feasibility of TBS and ADD on the real forensic cases. Overall, our finding suggested that the quantitative method could be used to produce PMI estimates that are accurate to within days or even hours.

• The Korean Journal of Legal Medicine
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• v.42 no.4
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• pp.126-140
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• 2018

The diagnosis of cause of death (COD) or estimation of postmortem interval (PMI) is hard to perform using postmortem blood or other bodily fluids due to various biochemical changes that occur during the agonal phase or after death. To solve these problems, new paradigms and new analytical methods are needed. In this study, postmortem blood was fractionated with specific gravity 1.021, 1.029, 1.038, and 1.045, and the absorbance patterns of each sample of the 131 total cases (12 kinds of COD) were analyzed using a spectrometer. The absorbance was grouped into 9 patterns (ABS pattern 1 to 9) according to the wave length and the signal intensity. These patterns of postmortem blood were found to be distinctly different from the absorbance pattern of fresh blood. The analysis of ABS patterns is useful for the diagnosis of deaths due to acute or rapid bleeding, fire death, drowning and, in some cases, poisoning, but is not useful for the estimation of PMI.

• Molecules and Cells
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• v.40 no.6
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• pp.410-417
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• 2017

Estimation of postmortem interval (PMI) is a key issue in the field of forensic pathology. With the availability of quantitative analysis of RNA levels in postmortem tissues, several studies have assessed the postmortem degradation of constitutively expressed RNA species to estimate PMI. However, conventional RNA quantification as well as biochemical and physiological changes employed thus far have limitations related to standardization or normalization. The present study focuses on an interesting feature of the subdomains of certain RNA species, in which they are site-specifically cleaved during apoptotic cell death. We found that the D8 divergent domain of ribosomal RNA (rRNA) bearing cell death-related cleavage sites was rapidly removed during postmortem RNA degradation. In contrast to the fragile domain, the 5' terminal region of 28S rRNA was remarkably stable during the postmortem period. Importantly, the differences in the degradation rates between the two domains in mammalian 28S rRNA were highly proportional to increasing PMI with a significant linear correlation observed in mice as well as human autopsy tissues. In conclusion, we demonstrate that comparison of the degradation rates between domains of a single RNA species provides quantitative information on postmortem degradation states, which can be applied for the estimation of PMI.

• Journal of Veterinary Science
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• v.25 no.3
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• pp.24.1-24.9
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• 2024

Importance: In veterinary forensic science, accurately determining the postmortem interval (PMI) is crucial for identifying the causes of animal deaths. Autolysis, a significant postmortem process, influences PMI estimation, but its relationship with humidity is not well understood. Objective: This study aimed to improve the accuracy of PMI estimates in veterinary forensic cases by looking into how different humidity levels affect autolysis in different organs of rats. Methods: The study involved 38 male rats, examining histopathological changes in their heart, liver, and pancreas. These organs were subjected to controlled humidity levels (20%, 55%, and 80%) at a constant 22℃. Tissue samples were collected at several intervals (0 h, 12 h, 24 h, 3 days, and 8 days) for comprehensive analysis. Results: Distinct autolytic characteristics in animal organs emerged under varying humidity conditions. The low-humidity environment rapidly activated autolysis more than the high-humidity environment. In addition, it was found that lower humidity caused nuclear pyknosis, cytoplasmic disintegration, and myofiber interruption. The liver, in particular, showed portal triad aggregation and hepatocyte individuation. The pancreas experienced cell fragmentation and an enlarged intracellular space. High humidity also caused the loss of striations in cardiac tissues, and the liver showed vacuolation. Under these conditions, the pancreas changed eosinophilic secretory granules. Conclusions and Relevance: The study successfully established a clear connection between the autolytic process in PMIs and relative humidity. These findings are significant for developing a more accurate and predictable method for PMI estimation in the field of veterinary forensic science.

• Journal of Science Criminal Investigation
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• v.11 no.3
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• pp.178-185
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• 2017

It is one of the most important factors to statistical estimation of ambient temperature for accumulated degree day (ADD) and minimum postmortem interval (PMI) in the incident scene. Until now, we applied the temperature of the nearest weather stations, adjusted temperature, or estimated the temperature by the linear regression analysis to estimate the temperature of the incident site. At this time, the estimated temperature may be changed according to the method of temperature estimation. And The accuracy of the estimated value may also vary depending on the environmental factors such as capacity, wind speed, humidity, and rainfall, which may affect measurement conditions and temperature. Therefore, we studied the effect of various environmental factors and measurement conditions for ambient temperature in Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.5
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• pp.701-710
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• 2019

Objective: This study investigated the effect of different acute heat stress (HS) levels on chicken meat quality and ultra-structure. Methods: Chickens were randomly divided into 7 groups to receive different HS treatments: i) $36^{\circ}C$ for 1 h, ii) $36^{\circ}C$ for 2 h, iii) $38^{\circ}C$ for 1 h, iv) $38^{\circ}C$ for 2 h, v) $40^{\circ}C$ for 1 h, vi) $40^{\circ}C$ for 2 h, and vii) un-stressed control group ($25^{\circ}C$). Blood cortisol level, breasts initial temperature, color, pH, water holding capacity (WHC), protein solubility and ultra-structure were analyzed. Results: HS temperatures had significant effects on breast meat temperature, lightness ($L^*$), redness ($a^*$), cooking loss and protein solubility (p<0.05). The HS at $36^{\circ}C$ increased $L^*{_{24h}}$ value (p<0.01) and increased the cooking loss (p<0.05), but decreased $a^*{_{24h}}$ value (p<0.05). However, as the temperature increased to $38^{\circ}C$ and $40^{\circ}C$, all the values of $L^*{_{24h}}$, cooking loss and protein denaturation level decreased, and the differences disappeared compared to control group (p>0.05). Only the ultimate $pH_{24h}$ at $40^{\circ}C$ decreased compared to the control group (p<0.01). The pH in $36^{\circ}C$ group declined greater than other heat-stressed group in the first hour postmortem, which contributed breast muscle protein degeneration combining with high body temperature, and these variations reflected on poor meat quality parameters. The muscle fiber integrity level in group $40^{\circ}C$ was much better than those in $36^{\circ}C$ with the denatured position mainly focused on the interval of muscle fibers which probably contributes WHC and light reflection. Conclusion: HS at higher temperature (above $38^{\circ}C$) before slaughter did not always lead to more pale and lower WHC breast meat. Breast meat quality parameters had a regression trend as HS temperature raised from $36^{\circ}C$. The interval of muscle fibers at 24 h postmortem and greater pH decline rate with high body temperature in early postmortem period could be a reasonable explanation for the variation of meat quality parameters.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.2
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• pp.108-113
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• 2017

A sudden cardiac death (SCD) is defined as an unnatural sudden death caused by heart disease. To determine the cause of death, observation of the microscopic change in cardiac muscle tissue is suggested, rather than visual postmortem examination. However, this suggestion is time consuming to be applied in the field, is cost-ineffective, and is inconvenient. Therefore, the purpose of this study is to understand whether temporary inspection used to examine the cardiac marker (Myoglobin, CK-MB, cTn I) in postmortem blood via rapid cardiac triple test kit (which is used by clinics to diagnose patients with acute myocardial infarction) can effectively be utilized for the paragnosis of sudden, unnatural cardiac death. The results of postmortem examination and temporary investigation found that 23 groups (76.7%), among the 30 experimental groups, were assumed to be non-traumatic sudden cardiac deaths, which indicated a positive response (according to comparison with forensic autopsy); 4 groups, among the 10 control groups, were assumed to be cerebrovascular disease, which indicated a negative response; 1 group was assumed to be alcoholic and drug poisoning, indicating a positive response; and 1 group was assumed to be oxygen deficiency due to suffocation, indicating a positive response. Hence, it was found that the level of sensitivity and specificity of cardiac marker's temporary inspection showed significant result, 76.7% and 80% respectively. Given this, temporary inspection can be effectively used for the paragnosis of sudden cardiac death when the medical history, situation of the site, and postmortem interval are considered together. With the result of precedent research on time of first revelation and extinction in blood, and difference in concentration over time progress according to the characteristic of cardiac marker's (myoglobin, CK-MB, cTn I) individual material, further research on concentration of cardiac marker per each post time needs to be conducted in order to estimate time science death (which is required to identify the cause of death and investigation).

• Journal of Life Science
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• v.18 no.10
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• pp.1400-1409
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• 2008

This study was carried out to offer the forensic entomological evidence to estimate the postmortem interval (PMI) based on the decomposing state of the pig carrion and the arthropod succession in exposed carrion. A total of 48 species of 28 families belonging to 7 orders were collected, and dominant insect varied with season, i. e., the Calliphoridae in March, May and October, both of the Calliphoridae and the Staphylinidae in July, and the Staphylinidae in September. The Calliphoridae was the first visiting insect throughout all the seasons as well as the index insect dominant in the early decomposing stage. The index insect in the later decomposing stage, however, was the Staphylinidae throughout all the seasons except in March. In March, the Muscidae was dominant, presumably because the flies consistently arrived throughout the extended period of decomposition of the carrion owing to the low ambient temperature of the season. In this connection, it is known that not only the decomposition stage of the carrion and the carrion-associated insect but also the climatological condition of the region have to be taken into consideration to estimate the PMI.

• Korean Journal of Veterinary Service
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• v.33 no.1
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• pp.29-35
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• 2010

This study was performed to test the hypothesis that Brucella abortus strain RB51 (SRB51) might protect Korean indigenous mongrel dog against challenge with either virulent B. abortus biotype 1 or B. canis. A total of 12 Korean mongrel dogs were divided into four groups (Group A, B, C and D). Dogs belonging to Group A and C were inoculated subcutaneously with $1{\times}10^9$ CFU of SRB51 in 1ml of sterile phosphate buffered saline (PBS). Dogs of Group B and D were inoculated subcutaneously with 1ml of sterile PBS as control. At 12 weeks post vaccination, dogs of Group A and B were challenged by oral inoculation of virulent strain of B. canis ($5.0{\times}10^9$ CFU) and dogs of Group C and D were challenged by oral inoculation of virulent strain of B. abortus biotype 1 ($4.4{\times}10^{10}$ CFU). The serum antibodies titers in all dogs were monitored at regular interval for eight weeks after challenge (AC) by standard tube agglutination test, plate agglutination test, rose bengal test, 2-mercaptoethanol rapid slide agglutination test and 2-mercaptoethanol tube agglutination test. No antibody titers in Group A and C was detected. Also, the challenge strains were not found from blood of all dogs of Group A and C from 1 week AC till the end of the experiment by culture and modified AMOS-PCR, whereas B. canis and B. abortus challenge strains were detected from blood of Group B and D, respectively. In addition, neither of two challenge bacteria was recovered from liver, spleen, kidneys, lymph nodes and reproductive tracts of Group A and C dogs after postmortem. However, B. canis and B. abortus challenge strains were isolated from these tissues of Group B and D, respectively. These data suggest that SRB51 could be a promising vaccine candidate for immunizing dogs to control canine brucellosis caused by B. canis or B. abortus.

• Journal of agriculture & life science
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• v.43 no.4
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• pp.21-31
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• 2009

Dipterans are excellent insects to serve as forensic indicators to determine the postmortem interval of a human corpse. Therefore, we undertook a study to identify the major dipterans that are attracted to and develop in vertebrate carcasses. To determine what dipterans occur in Korea, chicken carcasses were placed in various habitats including the forest, open field, stream bank, greenhouse, rooftop, rice paddy, Chinese cabbage field, vacant hut, and pond at different times of the year. The dipterans were collected at various time intervals after placement in each habitat until the end of decomposition and identified. Our results showed that 49 identified and unidentified dipteran species from 36 genera in 19 families were collected from the carcasses. Habitat placement influenced the number of species isolated from the carcasses. For example, 39 species were collected from the forest habitat, 28 species from the open field, stream bank, or greenhouse each, 16 species from a vacant home, and 12 species from the pond. The dipteran species that were collected from all habitats were Phaenicia sericata, Lucilia illustris, and Lucilia sp. in the family Calliphoridae and Boettcherisca peregrine in the family Sarcophagidae. Other dipteran species that were isolated depended on carcass placement that is, fewer dipteran species were observed from carcasses in the backpack and much more species were recorded from unburied carcasses than buried carcasses. P. sericata, L. illustris, Lucilia sp., B peregrine and an unidentified sarcophagid species were observed year round, but some dipterans showed seasonal differences.