Immunohistochemical analysis of PDGFR-α for wound age determination.

Immunohistochemical analysis of platelet-derived growth factor receptor-α (PDGFR-α) was performed on human skin wounds obtained from forensic autopsy cases. Thirty human skin wounds were collected at different post-infliction intervals as follows: Group I, 4 h to 3 days (n = 16); Group II, 4 to 7 days (n = 7); Group III, 9 to 10 days (n = 3); and Group IV, 14 to 20 days (n = 4). Immunopositive reactions for PDGFR-α were not observed in the uninjured human skin specimens. In a semi-quantitative morphometrical analysis, the number of PDGFR-α-positive cells was observed increased in Group II, with the average number of PDGFR-α-positive cells being the highest in Group II. Additionally, in Group II, all specimens showed PDGFR-α-positive cells, with an average number of > 200 cells in five fields of view, suggesting a wound age of 4 to 7 days. Taken together, the immunohistochemical detection of PDGFR-α in human skin wounds can be a useful tool for wound age determination.

Biochemical analysis of catecholamine and cortisol for the evaluation of the fetal distress in third trimester stillbirths.

BACKGROUND: Stress hormones like catecholamine and cortisol are thought to reflect the magnitude of physical stress in adults and were studied in relationship to the cause of death and agony time. Intrauterine distress, intrapartum events, and modes of delivery can affect the fetal endocrine stress response, as reflected by biochemical analyses. The aim of the present study was to evaluate the role of catecholamines and cortisol as markers of ante-mortem fetal distress. The role of cortisol as a marker of circadian timing of delivery was also assessed. METHODS: A 2-year prospective cohort-comparison inclusion of stillbirths and newborns took place with collection of antemortem data, labor parameters, neonatal outcome, post-mortem data and blood samples. Stillbirths were classified as acute or chronic on the basis of a multidisciplinary evaluation. Heart blood of stillbirths and cord blood of newborns were analyzed by high pressure liquid chromatography (HPLC) for adrenaline and noradrenaline and by immunoassay for cortisol determination. RESULTS: Fifteen stillbirths and 46 newborns, as a comparison group, delivered by spontaneous vaginal birth, elective, and emergency cesarean sections were included. Stillbirths' main cause of death was cord thrombosis. Levels of adrenaline and noradrenaline (median: 14,188 pg/ml and 230.5 pg/ml, respectively) were significantly higher (p < 0.001) in stillbirths than in newborns and were also higher in acute compared to chronic distress. Cortisol levels were significantly higher (p < 0.05) in spontaneous vaginal delivery (median: 18.2 µg/dl) compared to elective cesarean sections (median: 3.8 µg/dl). No difference in cortisol concentrations was detected between newborns delivered at morning and at afternoon/evening. CONCLUSION: Our results suggest that the biochemical measurement of adrenaline and noradrenaline levels might reflect a marked physical stress response during the process of death in stillbirths. On the contrary, the elevation of cortisol levels could mirror the elevation in maternal cortisol level during vaginal delivery. For the post-mortem evaluation of stillbirths, the analysis of CA levels could provide additional data on the duration of distress, useful to integrate the forensic diagnosis.

A computational approach to estimate postmortem interval using postmortem computed tomography of multiple tissues based on animal experiments.

The estimation of postmortem interval (PMI) is a complex and challenging problem in forensic medicine. In recent years, many studies have begun to use machine learning methods to estimate PMI. However, research combining postmortem computed tomography (PMCT) with machine learning models for PMI estimation is still in early stages. This study aims to establish a multi-tissue machine learning model for PMI estimation using PMCT data from various tissues. We collected PMCT data of seven tissues, including brain, eyeballs, myocardium, liver, kidneys, erector spinae, and quadriceps femoris from 10 rabbits after death. CT images were taken every 12 h until 192 h after death, and HU values were extracted from the CT images of each tissue as a dataset. Support vector machine, random forest, and K-nearest neighbors were performed to establish PMI estimation models, and after adjusting the parameters of each model, they were used as first-level classification to build a stacking model to further improve the PMI estimation accuracy. The accuracy and generalized area under the receiver operating characteristic curve of the multi-tissue stacking model were able to reach 93% and 0.96, respectively. Results indicated that PMCT detection could be used to obtain postmortem change of different tissue densities, and the stacking model demonstrated strong predictive and generalization abilities. This approach provides new research methods and ideas for the study of PMI estimation.

Development of a screening system of gene sets for estimating the time of early skeletal muscle injury based on second-generation sequencing technology.

The present study is aimed to address the challenge of wound age estimation in forensic science by identifying reliable genetic markers using low-cost and high-precision second-generation sequencing technology. A total of 54 Sprague-Dawley rats were randomly assigned to a control group or injury groups, with injury groups being further divided into time points (4 h, 8 h, 12 h, 16 h, 20 h, 24 h, 28 h, and 32 h after injury, n = 6) to establish rat skeletal muscle contusion models. Gene expression data were obtained using second-generation sequencing technology, and differential gene expression analysis, weighted gene co-expression network analysis (WGCNA) and time-dependent expression trend analysis were performed. A total of six sets of biomarkers were obtained: differentially expressed genes at adjacent time points (127 genes), co-expressed genes most associated with wound age (213 genes), hub genes exhibiting time-dependent expression (264 genes), and sets of transcription factors (TF) corresponding to the above sets of genes (74, 87, and 99 genes, respectively). Then, random forest (RF), support vector machine (SVM) and multilayer perceptron (MLP), were constructed for wound age estimation from the above gene sets. The results estimated by transcription factors were all superior to the corresponding hub genes, with the transcription factor group of WGCNA performed the best, with average accuracy rates of 96% for three models' internal testing, and 91.7% for the highest external validation. This study demonstrates the advantages of the indicator screening system based on second-generation sequencing technology and transcription factor level for wound age estimation.

Motorcycle injuries: a systematic review for forensic evaluation.

The intricate interplay of exposure and speed leave motorcyclists vulnerable, leading to high mortality rates. During the collision, the driver and the passenger are usually projected away from the motorcycle, with variable trajectories or final positions. Injuries resulting from the crash can exhibit distinct and specific characteristics depending on the circumstances of the occurrence.The aim of this study is to provide a systematic review of the literature on injuries sustained by motorcyclists involved in road accidents describing and analyzing elements that are useful for forensic assessment.The literature search was performed using PubMed, Scopus and Web of Science from January 1970 to June 2023. Eligible studies have investigated issues of interest to forensic medicine about during traffic accidents involving motorcycle. A total of 142 studies met the inclusion criteria and were classified and analyzed based on the anatomical regions of the body affected (head, neck, thoraco-abdominal, pelvis, and limb injuries). Moreover, also the strategies for preventing lesions and assessing injuries in the reconstruction of motorcycle accidents were examined and discussed.This review highlights that, beyond injuries commonly associated with motorcycle accidents, such as head injuries, there are also unique lesions linked to the specific dynamics of accidents. These include factors like the seating position of the passenger or impact with the helmet or motorbike components. The forensic assessment of injury distribution could serve as support in reconstructing the sequence of events leading to the crash and defining the cause of death in trauma fatalities.

Forensic pilot application of rehydrating solutions on human cadaveric skin: what are the effects on hemorrhagic infiltrates?

The microscopic evaluation of hemorrhagic infiltrates is crucial in forensic diagnostics, but it proves challenging in corificated and mummified cadavers. In these cases, pre-treatment with rehydrating solutions is recommended, although their effects on the hemorrhagic infiltrate are not well understood. In this pilot study, we microscopically investigated the effect of two different rehydrating solutions-Sandison's solution and fabric softener-on well-preserved human cadaveric skin samples taken from areas affected by an ecchymotic lesion, comparing them with direct fixation in formalin. Specifically, we examined the topographic distribution of the hemorrhagic infiltrate in each layer of the skin by assigning a semi-quantitative score, conducted mutual comparisons, and performed statistical analysis. Histologically, compared to direct fixation in formalin, a slight and statistically non-significant reduction in the hemorrhagic infiltrate was observed in samples pre-treated with fabric softener. On the other hand, a more pronounced and statistically significant decrease in scores was observed in samples pre-treated with Sandison's solution. This effect is likely due to the fact that Sandison's solution, due to its components, exerts an osmotic effect, partially inducing osmotic lysis of red blood cells. Overall, extensive areas of hemorrhagic infiltrates were preserved, although to a lesser extent, while smaller foci were markedly reduced, sometimes even disappearing. The findings suggest that Sandison's solution has a detrimental effect on cutaneous hemorrhagic infiltrates, emphasizing the importance of being cautious and conducting dual sampling, using both formalin and a rehydrating solution, for forensic examination of mummified or corificated skin samples.

From degraded to deciphered: ATAC-seq's application potential in forensic diagnosis.

In recent years, molecular biology-based diagnostic techniques have made remarkable strides and are now extensively utilized in clinical practice, providing invaluable insights for disease diagnosis and treatment. However, forensic medicine, especially forensic pathology, has witnessed relatively limited progress in the application of molecular biology technologies. A significant challenge in employing molecular techniques for forensic diagnoses lies in the quantitative and qualitative changes observed in diagnostic markers due to sample degradation-a recognized and formidable obstacle. Inspired by the success of DNA sequencing in forensic practices, which enables accurate individual identification even in cases involving degraded and deteriorated tissues and organs, we propose the application of the assay for transposase-accessible chromatin with sequencing (ATAC-seq) to identify targets at the transcriptional onset, exploring chromatin and DNA-level alterations for injury and disease inference in forensic samples. This study employs ATAC-seq to explore alterations in chromatin accessibility post-injury and their subsequent changes over a 2-h degradation period, employing traumatic brain injury (TBI) as a representative model. Our findings reveal high sensitivity of chromatin accessibility sites to injury, evidenced by shifts in thousands of peak positions post-TBI. Remarkably, these alterations remain largely unaffected by early degradation. Our results robustly endorse the notion that integrating and incorporating these specific loci for injury and disease diagnosis in forensic samples holds tremendous promise for practical application. We further validated the above results using human cortical tissue, which supported that early degradation did not significantly affect chromatin accessibility. This pioneering advancement in molecular diagnostic techniques may revolutionize the field of forensic science, especially forensic pathology.

Pediatric motor vehicle crashes injuries: A systematic review for forensic evaluation.

Children involved in car crashes can experience either direct trauma or inertial injuries resulting from interactions with external objects, such as other vehicles, or with the restraint system. Furthermore, improper use of restraint systems can lead to additional severe injuries. Recent reports from international institutions underscored the persistent prevalence of inadequate restraint systems utilization and this widespread issue increases children's vulnerability and risk of injuries.The aim of this study is to provide a systematic review of the literature on injuries sustained in children involved in road accidents describing and analyzing elements useful for forensic assessment.The literature search was performed using PubMed, Scopus and Web of Science from January 1970 to March 2023. Eligible studies have investigated issues of interest to forensic medicine about traffic accidents involving pediatric passengers. A total of 69 studies satisfied the inclusion criteria and were categorized and analyzed according to the anatomical regions of the body affected (head, neck, thoraco-abdominal, and limb injuries), and the assessment of lesions in reconstruction of the accident was examined and discussed.The review highlights that in motor vehicle accidents involving children, the forensic evaluation of both the cause of death and accident dynamics needs to consider several factors, such as the child's age, the type of restraint system employed, and the specific passenger seat occupied. Considering the complexity of the factors that can be involved in this road accident, it is crucial that there is a comprehensive exchange of information between the judge and the medical expert.

Postmortem CT analysis of paranasal sinuses using an experimental model of drowning.

Fluid-filled paranasal sinuses are suggested to be a valuable tool to distinguish between drowning and non-drowning postmortem, yet the mechanisms governing fluid entry remains unknown. We investigate if fluid-filled paranasal sinuses are caused by a passive influx from submersion or an active aspiration mechanism during drowning. The ovine nasal cavity and maxillary sinuses are remarkably similar anatomically to humans, and have been used for endoscopic surgical training in recent decades. We submerged 15 decapitated ovine heads from agricultural waste at a depth of 2 m in flowing water for 1, 8, and 24 h and 7 days. Paranasal sinuses were CT imaged and compared pre- and post-submersion to non-submerged controls. Furthermore, we examined the paranasal sinuses of a single homicide case of a non-drowned submerged subject. Results demonstrate that fluid passively enters the maxillary sinus postmortem in the non-drowned ovine heads following 1 h of submersion. Fluid volume was independent of submersion time and influenced by time out of water as well as handling, since volume was reduced between consecutive CT scans. In contrast to our hypothesis, the filling of the paranasal sinuses is due to passive influx of fluid from submersion rather than an active aspiration during drowning. The observation that paranasal sinuses were fluid-filled in a single medico-legal case of postmortem submersion supports the finding of passive influx. Consequently, careful interpretation of fluid-filled paranasal sinuses is required when bodies are found in water, as the finding cannot distinguish between postmortem submersion and drowning.

Subject-specific finite element head models for skull fracture evaluation-a new tool in forensic pathology.

Post-mortem computed tomography (PMCT) enables the creation of subject-specific 3D head models suitable for quantitative analysis such as finite element analysis (FEA). FEA of proposed traumatic events is an objective and repeatable numerical method for assessing whether an event could cause a skull fracture such as seen at autopsy. FEA of blunt force skull fracture in adults with subject-specific 3D models in forensic pathology remains uninvestigated. This study aimed to assess the feasibility of FEA for skull fracture analysis in routine forensic pathology. Five cases with blunt force skull fracture and sufficient information on the kinematics of the traumatic event to enable numerical reconstruction were chosen. Subject-specific finite element (FE) head models were constructed by mesh morphing based on PMCT 3D models and A Detailed and Personalizable Head Model with Axons for Injury Prediction (ADAPT) FE model. Morphing was successful in maintaining subject-specific 3D geometry and quality of the FE mesh in all cases. In three cases, the simulated fracture patterns were comparable in location and pattern to the fractures seen at autopsy/PMCT. In one case, the simulated fracture was in the parietal bone whereas the fracture seen at autopsy/PMCT was in the occipital bone. In another case, the simulated fracture was a spider-web fracture in the frontal bone, whereas a much smaller fracture was seen at autopsy/PMCT; however, the fracture in the early time steps of the simulation was comparable to autopsy/PMCT. FEA might be feasible in forensic pathology in cases with a single blunt force impact and well-described event circumstances.

An atypical case of fatal 'esophageal apoplexy': post-mortem findings and differential diagnosis.

Forensic pathologists need to have comprehensive knowledge of a large variety of causes of sudden natural death. We describe a case of sudden and unexpected death in woman in her sixties due to rupture of a large paraesophageal hematoma. The post-mortem examination and differential diagnosis are discussed. The combined findings of whole-body post-mortem CT imaging (PMCT), targeted PMCT angiography, autopsy, and histology are most in keeping with 'esophageal apoplexy'; a rare cause of hemorrhage in the esophageal wall. A review of the literature indicates that most cases of esophageal apoplexy are self-limiting and that fatal complications are exceedingly rare. Our case demonstrates that esophageal apoplexy can present as sudden unexpected death.

Current status of undergraduate teaching in forensic & legal medicine in Europe.

The European Council of Legal Medicine (ECLM) is the body established in 1992 to represent practitioners forensic & legal medicine and is composed of delegates of the countries of the European Union (EU) and from other countries which form part of Europe to a current total of 34 member countries. The aims of this study were to determine the current status of undergraduate forensic & legal medicine teaching in the curriculum of medical studies in ECLM countries and to use the results of this study to determine whether it would be appropriate to develop new guidelines and standards for harmonising the content of undergraduate forensic medicine training across ECLM member countries. A detailed questionnaire was sent to all individuals or organisations listed on the ECLM contact database. Responses were received from 21 of 33 countries on the database. These responses showed considerable emphasis on undergraduate teaching of forensic medicine in all countries with the exception of Belgium and the United Kingdom. There was great general consistency in the subjects taught. The data from this survey provide a baseline which should assist in developing a strategy to harmonise forensic & legal medicine undergraduate training in member countries of the ECLM. The ECLM is now in a good position to establish a pan-European working group to coordinate a consensus document identifying an appropriate and modern core undergraduate forensic medicine curriculum that can be presented to the medical education authorities in each country, and which can be adapted for local requirements, based on available personnel, the forensic medicine structure in the country, and most importantly, the needs of the local population.

Post-blast histological changes to three animal bones exposed to close-range chemical detonation.

A range of investigative practices to aid explosive-related death investigations currently exist, although the use of histopathological bone samples to diagnose blast exposure and the distance of individuals from the blast source has not been previously reported. Forensic histopathology has been used effectively on soft tissue samples to define blast-related injuries effectively, analysing human organs such as the lungs, brain, liver, and skeletal muscles, providing important and useful forensic pathology interpretations. However, no studies currently exist examining the post-blast histological changes in human or animal bones subjected to blasts for forensic pathology practice, despite the opportunity that hard tissue bone samples present, given their significantly lower rate of decomposition over soft tissue. This study presents the first evidence-based findings on the post-blast histological changes in three animal bones when exposed to close-range chemical detonation (C4). The study's qualitative findings highlight critical changes in the tissue architecture of three different animal bone sources due to blast effects with range from the blast source. This emphasises the potential use of histopathological bone sample analysis in future blast-related death investigations, while providing ideas to further explore this work using larger-scale experiments and post-blast case studies in aid of applying this work to human samples and forensic pathology practice.

Penile Pearls and Pearling: Characteristics and Social Identity from the Perspective of Forensic Pathologists.

Penile pearls are artificial implants placed beneath the skin of a penis to provide enhanced sexual experience for the partner or present a stigma of a particular social subgroup (e.g., prisoner, member of a gang). This genital modification is usually encountered in men of low socioeconomic status and prisoners who might (self) implant improvised pearls under poor sanitary conditions. We have only recently started to encounter penile pearls on autopsy, incidentally. The aim of this study was to analyze our autopsy cases with penile pearls to assess the characteristics of these subjects regarding their socioeconomic status, history of imprisonment, substance abuse, as well as the characteristics of implants. Nineteen men were included. Most were born in the 1970s and 1980s, with only elementary/vocational school education (n = 10). Only five men graduated from high school. At least 14 were in prison at some point in life and 13 were unemployed. Ten men were unmarried. In 11 men, regular alcohol consumption was reported. 12 used illicit substances, most with a history of heroin injection. Penile pearls were improvised and made of rigid plastic in 10 men, eight were of soft silicone-like material, and one was of metal. A distinct characteristic was a ribbed contour of some implants. Although this genital modification seems to gain more attention outside of described vulnerable groups, it mostly remains limited to them in our region. It is most likely performed in improvised, non-professional, unsanitary conditions, probably in prisons.

Application of Aquaporins as Markers in Forensic Pathology: A Systematic Review of the Literature.

The study of aquaporins (AQPs) in various forensic fields has offered a promising horizon in response to the need to have reliable elements for the identification of the manner of death and for the individuation of forensic markers for the timing of lesions and vitality of injury. In the literature, various tissues have been studied; the most investigated are the lungs, brain, kidneys, skin, and blood vessels. A systematic literature review on PubMed following PRISMA 2020 guidelines enabled the identification of 96 articles. In all, 34 of these were enrolled to identify Aquaporin-like (AQP-like) forensic markers. The analysis of the literature demonstrated that the most significant markers among the AQPs are as follows: for the brain, AQP4, which is very important in brain trauma and hypoxic damage; AQP3 in the skin lesions caused by various mechanisms; and AQP5 in the diagnosis of drowning. Other applications are in organ damage due to drug abuse and thrombus dating. The focus of this review is to collect all the data present in the literature about the forensic application of AQPs as forensic markers in the most important fields of application. In the current use, the individuation, validation, and application of markers in forensic investigation are very useful in real forensic applications in cases evaluated in court.

Potential Role of mRNA in Estimating Postmortem Interval: A Systematic Review.

Although the postmortem interval estimation still represents one of the main goals of forensic medicine, there are still several limitations that weigh on the methods most used for its determination: for this reason, even today, precisely estimating the postmortem interval remains one of the most important challenges in the forensic pathology field. To try to overcome these limitations, in recent years, numerous studies have been conducted on the potential use of the mRNA degradation time for reaching a more precise post mortem interval (PMI) estimation. An evidence-based systematic review of the literature has been conducted to evaluate the state of the art of the knowledge focusing on the potential correlation between mRNA degradation and PMI estimation. The research has been performed using the electronic databases PubMed and Scopus. The analysis conducted made it possible to confirm the potential applicability of mRNA for reaching a more precise PMI estimation. The analysis of the results highlighted the usefulness of some mRNAs, such as ß-actin and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA, especially in short time frames, within a few hours or days of death. The matrices on which these analyses were conducted were also analyzed, resulting in less exposure to the external environment, including the heart, brain, and dental pulp. The major limitations were also reported, including the short time intervals analyzed in most of the articles, the lack of mathematical models, and the failure to report the error rate between the mRNA degradation time and PMI. Given the still small number of published articles, the lack of globally recognized standardized methods, and the numerous techniques used to evaluate the mRNA degradation times, numerous and larger studies are still necessary to reach more solid and shared evidence.

microRNAs as New Biomolecular Markers to Estimate Time since Death: A Systematic Review.

Estimating the post-mortem interval is still one of the most complex challenges in forensics. In fact, the main tools currently used are burdened by numerous limitations, which sometimes allow the time of death to be placed only within too large time intervals. In recent years, researchers have tried to identify new tools to try to narrow down the interval within which to place the time of death; among these, the analysis of microRNAs seems to be promising. An evidence-based systematic review of the literature has been conducted to evaluate the state of the art of knowledge, focusing on the potential correlation between miRNA degradation and PMI estimation. The research has been performed using the electronic databases PubMed, Scopus, and WOS. The results allowed us to highlight the usefulness of miRNAs both as markers for PMI estimation and for normalization, especially due to their stability. In fact, some miRNAs remain particularly stable for long periods and in different tissues, while others degrade faster. Furthermore, there are numerous factors capable of influencing the behavior of these molecules, among which the type of tissue, the cause of death, and the circadian rhythm appear to be the most relevant. Despite the promising results of the few articles present in the literature, because of the numerous limitations they are burdened by, further research is still necessary to achieve more solid and shareable results.

Significance of Contusion at the Vocal Cord and Perivocal Cord Area in Cases of Non-intubated Death.

Every finding during a neck autopsy may be essential for accurately diagnosing and explaining the mechanism of death. In this prospective study in the Department of Forensic Medicine and Toxicology of Jordan University Hospital, 17 out of 95 neck autopsies revealed contusions of the laryngeal mucosa in the vocal or perivocal area. These contusions were found to be associated with various causes of death, including mechanical asphyxia (such as throttling, ligature strangulation, hanging, smothering, choking, plastic bag asphyxia, gagging, and inhalation of blood) and other causes (such as atypical drowning, carbon monoxide poisoning, head injury due to a road traffic accident, burns, electrocution, and brain edema). This study provides insight into the mechanisms of this important lesion and may contribute to a better understanding of the cause of death.

Sudden cardiac death due to an obstructive large right atrial myxoma.

Sudden cardiac death is a phenomenon that affects more than 200,000 individuals annually in the United States. Among sudden cardiac deaths, only a fractionally small portion is thought to be attributable to intracardiac neoplasms. Though rarely implicated as the primary cause of death, cardiac myxomas are the most common benign neoplasms of the heart and have been known to cause death due to multifactorial embolic events, fatal arrhythmias, and frank obstructive events. In this case, a healthy, asymptomatic young male was found unresponsive in his residence. Examination of the heart at autopsy revealed dilation of the right atrium and a large, hemorrhagic, irregular, and obstructing mass arising from the right atrium, consistent with cardiac myxoma. When unusual cardiac findings are discovered at autopsy, a systematic investigation of the heart, including retaining the organ for cardiac pathology consultation, is mandatory to correctly identify the cause of death.

Cardiac rhabdomyoma: an uncommon culprit in sudden infant death.

Sudden death in infants remains a common and poorly understood cause of childhood mortality in the USA. Pediatric cardiac tumors, although rare, may underlie some cases of unexplained sudden infant death. Autopsy is a crucial diagnostic step in these cases, as both gross and microscopic examination of the heart may uncover occult cardiac tumors. Rhabdomyomas are the most common cardiac tumors in childhood and may result in arrythmia and sudden death. We present a case of sudden death in a healthy 5-month-old infant which initially appeared "SIDS-like" until thorough histological analysis revealed an underlying cardiac rhabdomyoma. The case is of particular importance in that the gross examination of the heart was considered completely normal, and the tumor only involved certain portions of the heart microscopically. Had a single random section of myocardium been the only heart section examined microscopically, the diagnosis might have been missed. This case emphasizes the importance of thorough microscopic examination in infant cases, especially in cases where the heart appears grossly normal.