Postmortem Period Research Articles

On the prospects of the impedance monitoring method for determining the prescription of death coming

The aim of the scientific work is to analyze the prospects of using the impedance monitoring method to determine the prescription of death coming. The conducted exploratory analysis allows hypothesizing the dependence of impedance values and dispersion factors for the diagnostic zones studies on the postmortem interval; it also suggests that it is possible to determine this interval for the objects (pig corpses) studies with a combination of impedance values and the corresponding factors. Among large mammals, a swine is the closest to a human from the point of analyzing the postmortem period process, and it can be recommended as an adequate human corpse model. When determining the correlation between the postmortem interval and the impedance parameters, it is the simplicity and reproducibility of the method, the absence of expensive equipment, its portability and the rapid receipt of results that allow this method to be applied at the scene, reinforcing traditional forensic methods for determining the prescription of death coming. Interpretation of impedance monitoring results can be used to analyze the biological nature of the postmortem period processes.

Injuries after the biological exposure

The aim of the scientific work is to justify the need to highlight the topic of injuries after the biological exposure in forensic medicine. The definition of the «biological trauma» concept is presented - it means impairment of the body structure and function as a result of a special injury effects typical for wildlife representatives (animals, plants). Biological exposure includes antigenic, toxin, allergic, bioelectric, bioorganic exposures and their combinations. Biological injuries should be distinguished from mechanical injuries caused by small, medium, and large mammals and reptiles. Options of the antemortem and postmortem biological factor effects are considered. The qualitative limits of the postmortem period are defined. A new method of forensic reconstruction of postmortem conditions is proposed. Forensic entomological, forensic microbiological examinations, and their complex combination with forensic examination are isolated as independent methods.

Modern ideas about the stages of decomposition and the possibilities of forensic reconstruction of the conditions of the postmortem period

The decomposition of a corpse is a long process in time and is one of the irreversible, as it is due to the natural need for the natural recycling of nutrients in dead organic matter (dead bodies of humans and animals). The duration of decomposition varies within very wide boundaries: from several months to several hundred and thousands of years. The article conducted an analytical review of works on the processes occurring in the dead body, the staging of decomposition, and the possibilities of forensic medical reconstruction of the conditions of the postmortem period, including the establishment of the duration of the post-mortal interval. A modern approach to the consideration of postmortem changes is presented, indicating that establishing the conformity of the pathomorphology of the decomposition of corpse tissues and its underlying abiotic and biotic factors can be a justification for its actual stages. However, the degradation characteristics of dead bodies depend on a number of factors acting together on the corpse and often catalytically or inhibitively acting on each other. All these changes, with the possibility of their comprehensive analysis (taking into account numerous factors affecting their dynamics), play a crucial role in establishing the duration of the postmortal interval.

Characteristics of histochemical, molecular genetic and radiation-induced liver changes depending on the postmortem interval

The aim of this study is to analyze literature data on postmortem changes in the liver and their use in determination of postmortem interval. Biological death expectedly causes the development of postmortem disorders not only in the liver structure, but also changes in its biochemical and histochemical parameters. Literature data about changes of histochemical, immunohistochemical and biomolecular characteristics of liver tissue, as well as bacterial migration to the liver depending on the duration of postmortem period, are presented. The effectiveness of radiology for visualization of postmortem changes and, accordingly, for determining the postmortem interval is noted.

Histopathological changes as tools to discriminate antemortem and post-mortem wounds in rats: prospective applications in forensic medicine

Wound age estimation is one of the chief exciting subjects in forensic medicine. It is substantial to determine the most likely accurate when wounds happened, whether during antemortem or post-mortem conditions. Moreover, histological change is a method that assists available parameters in determining the antemortem and post-mortem period. This study aims to observe the histopathological changes in induced wounds to determine when the injury occurred and whether the injury occurred during antemortem or post-mortem conditions. Thirty-nine rat wound skin biopsies were studied. All samples were taken in antemortem groups at 30, 60, 180, and 360 min, and in post-mortem groups within 30, 60, 180, and 360 min with control samples (unwounded group). The skin sections were seen by microscope to observe the changes in the following criteria: the ratio and distribution of the neutrophil and macrophage, congestion and dilatation of capillaries, and degree of autolysis. For the antemortem wounds, the number of neutrophils appeared at 30 minutes and sharply increased from 60 minutes after the wound. In addition, there was an increase in macrophages from 180 min after the wound. For the post-mortem wounds in all times examined, the degree of autolysis was the best criterion for knowing the wound timing. These results propose that histopathological changes can be used as a critical criterion for finding the time of wounds and comparing antemortem and post-mortem incisional wounds in forensic medicine.

Cytomorphological characteristics of necroptates of internal organs of dogs in the early post-mortem period in the aspect of forensic veterinary examination

The relevance of the study lies in the need for forensic veterinary examination of animal corpses for scientific justification of informative diagnostic criteria for assessing the prescription of death, especially in the early post-mortem period. However, information about early post-mortem changes in dog cadavers at the microstructural level in the Ukrainian and foreign scientific literature is quite fragmentary. In this regard, the purpose of this paper is to establish the informative dynamics of the processes of cell destruction and bacterial contamination of internal organs of dog corpses during the first post-mortem day to establish probable expert criteria for the prescription of death of sub-expert animals during the forensic veterinary examination. A leading approach to the investigation of this problem is the method of obtaining a series of necroptates from lungs, heart, liver, spleen, kidney, pancreas, and brain from canine cadavers, over the same time interval during the first day after death. In cytological preparations obtained from necroptates, the number of destroyed cells and bacterial units was counted using optical microscopy. Based on the results of the dynamics of bacterial contamination and the intensity of morphological changes in spleen and pancreatic cells, their expert information content was established to solve the question of the prescription of death of dogs, regardless of weight and fatness indicators. It was found that the dynamics of bacterial contamination and cellular destruction of the brain, kidneys, and lungs of dog corpses have average expert information content, while the liver and heart are not informative. It was proved that the dynamics of destructive post-mortem processes in the cells of the compact organs of the corpses of dogs of different weight and fatness at the appropriate times probably do not differ and develop with the same intensity. The obtained results of the study will have significance both in the theory of forensic veterinary examination and directly applied, specifically when the forensic expert solves the question regarding the time limit for the death of the animal

Fetal skeletal dysplasia cohort of a single tertiary referral center in Istanbul, Turkey.

We report on 314 fetal cases from 297 unrelated families with skeletal dysplasia evaluated in the postmortem period from 2000 to 2017 at a single clinical genetics center in İstanbul, Turkey. The definite diagnostic yield was 40% during the prenatal period, while it reached 74.5% when combined with postmortem clinical and radiological evaluation. Molecular analyses were performed in 25.5% (n: 76) of families, and 21 novel variants were identified. Classification according to International Skeletal Dysplasia Society-2019 revision revealed limb hypoplasia-reduction defects group (39) as the leading one, 24.5%, then followed by FGFR3 chondrodysplasias, osteogenesis imperfecta, and decreased mineralization and polydactyly-syndactyly-triphalangism groups 13.6, 11.1, and 8.9%, respectively. The inheritance pattern was autosomal recessive in 54% and autosomal dominant in 42.6% of index cases. The overall consanguinity rate of the cohort was 33%. The high prevalence of ultrarare diseases along with two or more unrelated autosomal recessive entities running in the same family was noteworthy. This study highlights the pivotal role of postmortem evaluation by an experienced clinical geneticist to achieve a high diagnostic yield in fetal skeletal dysplasia cohorts. The cohort is not only a representation of the spectrum of skeletal dysplasias in a population with a high consanguinity rate but also provides an ideal research group to work on to identify the unknowns of early fetal life.

Lipid transformation during postmortem chilled aging in Mongolian sheep using lipidomics

This present study aimed to investigate the effects of postmortem chilled aging on lipid and molecular transformation mechanisms in Mongolian sheep. UPLC-ESI-MS/MS was used to identify 812 lipids in Mongolian sheep within four days of chilled aging. Using multivariate analysis, 95 significant differential lipids were identified. The levels of phosphatidylcholine, phosphatidylinositol, and certain free fatty acids were observed to rise significantly, while other phospholipids and acylcarnitines showed a downward trend. In addition, levels of most of the lysophospholipids increased significantly in the early postmortem period; however, their levels did not alter significantly after 48 h. The Kyoto encyclopedia of genes and genomes pathway analysis revealed that these differential lipids are primarily involved in glycerophospholipid metabolism, linoleic acid metabolism, arachidonic acid metabolism, and thermogenesis. Our results have important implications in terms of understanding lipid transformation and changes in meat quality during postmortem chilled aging in Mongolian sheep.

Exploratory study on the potential regulating role of Peroxiredoxin 6 on proteolysis and relationships with desmin early postmortem

The objective of the present study was to explore the effect of Peroxiredoxin 6 (Prdx 6) on beef tenderization during the early postmortem period. The longissimus lumborum (LL) were obtained at 45 min postmortem from 6 beef carcasses and then incubated with or without the inhibitor of Prdx6 (NSC348884) for different times, followed by incubation with or without the H2O2 (simulation of oxidative stress). The expression of Prdx6, proteolysis indicated by desmin degradation, cell apoptosis rate and expression of caspases were measured. The results indicated that the inhibitor significantly reduced the Prdx6 level, while the cells adaptively increased Prdx6 expression to resist the oxidative stress caused by H2O2. Moreover, the samples in which Prdx6 was inhibited demonstrated more severe desmin degradation accompanied by a higher apoptosis rate which was induced by the increase in caspase degradation as well as the ratio of Bax/Bcl-2. These results demonstrated that inhibiting Prdx6 could promote cell apoptosis and further accelerate beef tenderization.

The Pink Teeth Phenomenon in Dogs and a Cat

The observance of pink teeth during the postmortem period in humans is known as the pink teeth phenomenon. In contrast, postmortem pink discoloration of teeth is rarely reported in veterinary medicine. We examined the teeth of nine dogs and a cat postmortem, all of which had varying degrees of pink discoloration of the teeth. Pink discoloration occurred in all types of teeth (incisors, canine, premolar, and molar). The roots of several teeth were discolored, ranging from pink to red, and over a 2–3 week period one dog’s lower incisors’ color changed from pink to red. Although the mechanism causing teeth to change color is suspected to be the uptake of hemoglobin within dentin tubules, the trigger for this phenomenon is not well understood. Our findings confirm the occurrence of the pink teeth phenomenon in dogs and a cat.

A method for estimating time since death through analysis of substances deposited on the surface of dental enamel in a body immersed in freshwater

Estimating the elapsed time after death of a corpse immersed in freshwater is often challenging owing to body temperature changes and the degree of postmortem lividity, and the tissues used for this assessment deteriorate drastically as the postmortem period progresses. In this study, assuming a corpse was immersed in freshwater, we analyzed changes in the amount of deposits on the enamel surface of teeth since the time of immersion using an electron probe microanalyzer. We calculated a regression equation for estimating the time of immersion in water (the time after death). We considered this approach would be useful to estimate the time after death even in rotting and skeletonized corpses from which only limited information could be obtained. This study was undertaken according to a previously reported method that used a regression equation for estimating the time after death of bodies found in a seawater area.

Drowning versus postmortem submersion: Biochemical and histopathological examination and estimation of postmortem intervals (an experimental study)

Estimation of the postmortem interval (PMI) is a very essential task for forensic experts especially in criminal cases. drowning is still the most difficult tasks for forensic pathologists to be diagnosed and differentiated from a body disposed of in water following death especially after long post-mortem period. The objective of this study was to estimate the PMI in drowning in comparison to postmortem submersion using mRNA expression of AQP1 in addition to histological and immunohistochemical examination of caspase-3 in the adrenal and thyroid glands of adult albino rats. Adult albino rats were divided into 2 groups; group A (drowning) and group B (post-mortem submersion). Thyroid and adrenal glands were examined at different PMI. The results revealed significant differences at AQP1 levels between drowning and postmortem submersion at different PMI. Histological changes and caspase-3 expression immunologically in both glands were helpful.

A comparative study of the toxic effect of ZIF-8 and ZIF-L on the colonization and decomposition of shaded outdoor mice carrions by arthropods

Metal–organic frameworks (MOFs) are promising materials for several applications. Thus, they have been intensively reported and commercialized by several international companies. However, little is known about the fate and risk of MOFs to living organisms. Here, the toxic effect of two Zinc (Zn)-based MOFs; zeolitic imidazolate frameworks (ZIF-8) and leaf-like ZIF (ZIF-L), was tested to investigate the impact of the postmortem period of mice carrions and arthropods which found in decomposing carrions. The data analysis revealed an increase in zinc content over time. Toxicology in forensics studies biological materials for the presence of poisons, such as pharmaceuticals. The toxicology report can provide important details about the types of chemicals present in a person and whether the amount of those substances is in line with a therapeutic dose or exceeds a dangerous level. These findings conclude the possible fate and impact after mortality. This study presents the first study of the toxic effect of ZIFs materials using mice carrions and arthropods (Sarcophaga sp. Larvae) via morphological and microscopic studies compared with control, providing important biological information could aid in the environmental impact of the toxic level of MOF materials.

TRENDS IN THE DEVELOPMENT OF FORENSIC MEDICAL TECHNOLOGIES FOR THE POSSIBILITY OF ACCURATE DETERMINATION OF THE TIME SINCE DEATH

Determining the exact time of death is a very important and signifi cant issue of forensic medical science and practice. Since traditional, routine techniques have many shortcomings and do not provide suffi cient accuracy in determining the postmortem interval, it is necessary to fi nd new ways and methods to solve this problem. The article presents an analysis of the state and trends in the development of tools and technologies of forensic science and practice used to accurately determine the time since death. The analysis of the scientifi c literature showed that, despite numerous and diverse studies aimed at determining the age of death, a large number of them have not found wide practical application. Thus, the search for new scientifi cally sound criteria is promising, based on chronological changes in biomarkers after death using modern technologies that will establish the time since death in the early and late post-mortem period.

Research Note: PSE condition is associated with increased apoptotic potential in broiler pectoralis major muscle

This study compared the meat quality and sensory quality characteristics of broiler pectoralis major (PM) muscle between meat quality classes, including reddish, firm, and non-exudative (RFN) and pale, soft, and exudative (PSE) conditions. Additionally, we also investigated the associations between the meat quality classes and expression levels of cytochrome c, initiator (caspase 9), and effector caspases (caspase 3 and 7) at the early postmortem period. A total of 135 PM muscles from broilers were used, and meat quality classes were determined according to the pH24 h and lightness values and classified into the RFN (N = 81) and PSE (N = 54) conditions. The PSE breasts showed lower muscle pH15 min and pH24 h values compared to the RFN breasts (P < 0.05). A lower lightness value was observed in the RFN group compared to the PSE group (P < 0.001), whereas there were no significant differences in redness and yellowness between the groups (P > 0.05). The PSE group exhibited higher extent of water loss, including drip loss and cooking loss, compared to the RFN group (P < 0.05). For these reasons, samples from the RFN group required less force to breakdown the cooked meat with more moisture in the mouth after chewing compared to samples from the PSE group (P < 0.001); however, flavor intensity did not differ between the groups (P > 0.05). At 15 min postmortem, all apoptosis-related molecules, including cytochrome c, caspase 9, caspase 3, and caspase 7, were present at higher levels in the PSE group than in the RFN group (P < 0.05). These results indicated that higher apoptotic potentials were associated with the development of PSE chicken breasts. Therefore, the variation of meat quality in chicken breast can be explained as being affected by the expression levels of apoptosis-related factors at the early postmortem period.

Biochemical and Physicochemical Changes in Spaghetti Meat During Refrigerated Storage of Chicken Breast.

This study investigated postmortem muscle protein degradation and myowater properties in broiler breasts afflicted with the Spaghetti Meat (SM) myopathy during 7 days of storage. Severe SM and unaffected (NORM) breast fillets were analyzed at days 0, 3, and 7 postmortem for TD-NMR myowater traits, myofibrillar protein profiles, calpain activity, free calcium, and desmin and troponin-T degradation patterns. Only at day 0, muscle histology, fiber size and sarcomere length were assessed on multiple fillet portions. In SM breasts, the intramyofibrillar water population exhibited longer relaxation times (p = 0.0172) and a lower proportion (p = 0.0118) compared to NORM. SM had a greater proportion of extramyofibrillar water (p = 0.0080) possessing a longer relaxation time (p = 0.0001). Overall, the SM myopathy had only a minor impact on the myofibrillar proteins profiles and did not affect either free calcium concentration, calpain activity, or the degradation of desmin and TnT, while storage time strongly affected all the traits measured. At microscopic level, muscle tissue from SM fillets exhibited the typical indicators of myodegeneration mostly in the superficial-cranial portion of the breast, while fiber size and sarcomere length were similar between the two muscle conditions irrespectively from the portion considered. The lack of overall significant interaction effects between muscle condition and storage period suggested that SM and NORM breast meat experience similar proteolytic and physical changes during the postmortem period.

Identification of fungi found on desiccated human remains in an arid outdoor environment.

Three fungi not previously reported on desiccated human remains were identified on cadavers at the Forensic Investigation Research Station (FIRS) in Whitewater, Colorado. The location of the FIRS provides the unique opportunity to observe the stages of decomposition in a high desert environment. The two cadavers used in the study were in the late stages of decomposition (PMI of approximately 1520 and 1820 days) to the point of desiccation and had developed an extensive black crust on the skin that remained. Skin samples of the two cadavers were taken and plated onto potato dextrose agar to determine whether fungi were present on the desiccated tissues. Three different fungi consistently dominated cultures grown from numerous samples taken from each cadaver. Based on morphological observations, nuclear rDNA sequence data, and phylogenetic analyses, two fungi were identified to species (Aureobasidium melanogenum and Didymella glomerata) and one fungus was identified to the genus level (Alternaria). These results will contribute to the understanding of the role that fungi might play in late-stage decomposition and the extended postmortem period.

Postmortem Electrical Conductivity Changes of Dicentrarchus labrax Skeletal Muscle: Root Mean Square (RMS) Parameter in Estimating Time since Death.

Simple SummaryThe estimation of postmortem interval (PMI) still poses a major challenge for pathologists worldwide, making the search for new and more accurate technologies to assist in PMI estimation worthy of growing scientific interest. This study aimed to explore for the first time the use of an oscilloscope coupled with a signal generator, as innovative technology, to evaluate changes in the electrical conductivity of skeletal muscle of sea bass specimens during the early postmortem interval, to find an accurate, quantitative parameter useful in PMI estimation. The use of the oscilloscope, especially for the RMS measured parameter, has been shown here as a promising technology for studying dielectric muscle properties during the early postmortem interval, with the advantage of being a rapid, non-destructive, and inexpensive method.Electric impedance spectroscopy techniques have been widely employed to study basic biological processes, and recently explored to estimate postmortem interval (PMI). However, the most-relevant parameter to approximate PMI has not been recognized so far. This study investigated electrical conductivity changes in muscle of 18 sea bass specimens, maintained at different room temperatures (15.0 °C; 20.0 °C; 25.0 °C), during a 24 h postmortem period using an oscilloscope coupled with a signal generator, as innovative technology. The root mean square (RMS) was selected among all measured parameters, and recorded every 15 min for 24 h after death. The RMS(t) time series for each animal were collected and statistically analyzed using MATLAB®. A similar trend in RMS values was observed in all animals over the 24 h study period. After a short period, during which the RMS signal decreased, an increasing trend of the signal was recorded for all fish until it reached a peak. Subsequently, the RMS value gradually decreased over time. A strong linear correlation was observed among the time series, confirming that the above time-behaviour holds for all animals. The time at which maximum value is reached strongly depended on the room temperature during the experiments, ranging from 6 h in fish kept at 25.0 °C to 14 h in animals kept at 15.0 °C. The use of the oscilloscope has proven to be a promising technology in the study of electrical muscle properties during the early postmortem interval, with the advantage of being a fast, non-destructive, and inexpensive method, although more studies will be needed to validate this technology before moving to real-time field investigations.

Beef Carcass Size and Aging Time Effects on Yield and Color Characteristics of Top Round Steaks

Variation in cut size and weight of fabricated subprimals is a challenge of increased beef carcass weights. Subsequently, variation in carcass size has resulted in consistency challenges during retail display. The objective of this study was to assess three aging periods of commercially available top rounds from varying carcass weights as it relates to yield and color characteristics. In the current study, 21 industry average weight (AW; 340 to 409 kg; no industry discount) beef carcasses and 21 oversized (OS; exceeding 454 kg; receive a discount) beef carcasses were evaluated. Carcasses were selected at a commercial beef packing plant, where the left and right (paired) top round subprimals of each carcass were procured. Paired top rounds were assigned to a short (8 d), average (23 d), or extended (42 d) postmortem aging period. After wet-aging, subprimals were fabricated into steaks for additional analysis. Steaks were evaluated as whole top round steaks or further fabricated into “ superficial ” and “ deep ” portions at 5.08 cm from the superficial edge of the Semimembranosus and the Adductor muscle. Top rounds and steaks from OS carcasses were larger (P &amp;lt; 0.01) than those from AW carcasses. Quantitative color of the anatomically deep locations of the OS steaks had the greatest mean L* (lightness; P &amp;lt; 0.01), a* (redness; P &amp;lt; 0.01) and b* (yellowness; P &amp;lt; 0.01) values. Extending the aging timeline increased L* (lightness; P &amp;lt; 0.01), decreased a* (redness; P &amp;lt; 0.01), and decreased b* (yellowness; P &amp;lt; 0.01). Alternative top round steak fabrication that separates the deep and superficial anatomical locations could be an effective means of providing more uniform steaks.

Analysis of Glial Fibrillary Acidic Protein and Ubiquitin C-Terminal Hydrolase L1 in Postmortem Serum and Cerebrospinal Fluid in Traumatic Cerebral Deaths

Objective: There is a growing body of research aimed at identifying biological markers that could indicate traumatic cerebral deaths such as traumatic brain damage in the postmortem period. In the event of astrocytic and neuronal injury, glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase L1 (UCH-L1) are released into cerebrospinal fluid and blood. In the postmortem identification of traumatic brain injury, the present research explores the ability of GFAP and UCH-L1.&#x0D; Methods: Cerebrospinal fluid and blood samples were obtained from medicolegal autopsies, 17 cases with severe head trauma, 9 cases with the non-lethal head trauma group and 18 control cases. UCH-L1 and GFAP levels in postmortem cerebrospinal fluid and serum were determined&#x0D; from an enzyme-linked immunosorbent assay (ELISA).&#x0D; Results: GFAP level in cerebrospinal fluid and serum was 2.68±0.67 ng/ml and 0.79±0.92 ng/ml in the lethal head trauma group, 2.74±0.64 ng/ml and 1.05±0.68 ng/ml the non-lethal head trauma group and 2.49±0.55 ng/ml and 1.05±0.89 ng/ml in the control group, respectively.&#x0D; UCH-L1 level in cerebrospinal fluid and serum was 3.02±0.68 ng/ml and 2.69±0.77 ng/ml in the lethal head trauma group, 3.34±0.70 ng/ml and 2.59±0.65 ng/ml the non-lethal head trauma group and 3.28±0.33 ng/ml and 2.74±0.34 ng/ml in the control group, respectively. Elevated cerebrospinal fluid and serum UCH-L1 and GFAP levels were observed in all cases, although absence of statistically significant difference between the trauma and control groups (p&gt;0.05).&#x0D; Conclusion: Further studies are needed to assess whether postmortem serum and CSF GFAP and UCH-L1 concentrations increase regardless of the cause of death.