International Journal of Legal Medicine最新文献

In this case report, sudden cardiac death caused by intussusception of a coronary artery is discussed. A 47-year-old man was found dead in the nursing home where he lived, following an episode of polyphagia and two of vomiting. Upon cadaveric dissection, an overdistention of the large intestine was noted. Re-evaluation of the formalin-fixed whole heart revealed occlusion of the circumflex branch of the left coronary artery, which was not macroscopically attributable to vascular thrombosis or an atheromatous plaque. Histological investigations revealed ischaemic-type histological changes of the left ventricular wall in a hyperacute phase of evolution and, in the occluded coronary branch, extensive intraluminal invagination of the intima and media, as occurs in vascular intussusception. Further stains revealed the presence of fibromuscular dysplasia of the wall of the affected vessel. The subject's death was ascribable to an acute cardiovascular failure secondary to acute ischaemic myocardial injury induced by intussusception of a coronary artery affected by dysplastic degeneration. These findings fully account for death by a mechanism sustained both by a mechanical deficit of the cardiac pump and by the possible onset of arrhythmias. Arterial intussusception is a rare complication of spontaneous coronary artery dissection. It is assumed that a combination of predisposing factors, which weaken the arterial wall, and trigger events, such as Valsalva-like activities, underlie the onset of the latter condition. This case highlights the importance of considering rare causes of sudden cardiac death. Greater awareness of these conditions can contribute to a more accurate identification of causes of death, with significant implications in both forensic and clinical settings.

Electrocution remains a significant cause of workplace fatalities, particularly in high-voltage environments. Diagnostic challenges arise from the often non-specific internal and external autopsy findings, necessitating robust evidence for reconstructing events and determining liability. This report presents a case of fatal high-voltage electrocution at a hydroelectric plant, focusing on the analysis of suspected electrical entry and exit wounds using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). A middle-aged male electrician sustained fatal injuries while working on a 63 kV transformer. Autopsy revealed electrical burns consistent with electrocution. SEM-EDS analysis identified an electrical entry wound on the right hand, characterized by metallization consistent with contact with a conductive object, specifically a metal tape measure found near the body. This finding supports a scenario involving safety protocol violations and human error. Multiple exit wounds were observed, a recognized phenomenon in high-voltage electrocutions. Notably, metallization was confirmed at exit wounds in skin samples from the left hand and feet, a finding typically considered a hallmark of electrical entry wounds. This unexpected observation underscores the importance of analyzing both entry and exit wounds with SEM-EDS to avoid misinterpretations. This case highlights the crucial role of SEM-EDS in the forensic analysis of electrical injuries, facilitating accurate event reconstruction and aiding in liability assessment.

Objectives: This paper presents a metric methodology for estimating biological sex specifically tailored to the Italian population. The method considers 121 standard metric measurements derived from 46 bones across various post-cranial regions.

Materials and methods: The sample consists of 400 individuals (M = 200; F = 200) from the 20th century CAL Milano Cemetery Skeletal Collection aged 20 to 104 years old. The sample was divided into a training subset (75%; n = 300) and a testing subset (25%, n = 100). Intra- and inter-observer analyses, as well as univariate sectioning points, and multivariable logistic regression analyses were performed.

Results: Intra- and inter-observer analysis showed excellent reproducibility of the measurements, with some exceptions generally related to the measurement of long bone diameters. Univariate sectioning points resulted in 18 measurements with accuracies exceeding 90%, and another 48 measurements achieving over 80% accuracy. In total, 43 multivariable logistic regression models were developed for 32 bones, and these models further increased the accuracy.

Discussion: The validation of these models demonstrated that the proposed methodology allows for sex estimation with accuracies of over or near 90% and minimal class discrimination bias across all post-cranial skeletal regions. The highest accuracies - with both sectioning points and multivariable models - were the radius (96.8%), scapula (95.3%), and tibia (95.2%). This study introduces a comprehensive metric standard for the Italian population and highlights the accuracy of the metric approach for estimating biological sex.

Accurate identification of body fluid stains found at crime scenes and inference of the time since deposition support forensic investigations. Forensic microbiology is recognized as a promising approach for addressing these challenges. Saliva and feces, which are frequently obtained as biological samples at crime scenes, contain greatly enriched bacterial communities. Therefore, we collected saliva and feces stains exposed to indoor environment. To simulate the time intervals typically encountered in forensic evidence examination, samples were exposed to indoor conditions for a 3-day short-term interval, and control samples were collected on the 3rd day to simulate the time point of arrest. We utilized the 16S rDNA full-length sequencing to characterize the microbial community. The results showed that microbial community composition of fresh body fluids, whether saliva or feces samples, remained stable on day 0 and day 3, with no substantial changes after 6 hour of exposure. The relative abundance of the dominant flora changed mainly after 24 h of exposure, such as an increase in Streptococcus oralis in saliva and a decrease in Bifidobacterium adolescentis in feces, and remained stable after 48 h and 72 h. The decrease in humidity seems to cause a reduction in some fluid flora, such as Prevotella melaninogenica in saliva. This suggests that collecting body fluid stain samples and recording environmental factors as early as possible after a case may increase the reliability of the evidence. In addition, saliva and feces stains exhibited distinct microbial composition profiles after exposure, indicating that they retained the potential for body fluid identification. The difference mainly stemmed from the respective dominant flora. Then, the time since deposition (TsD) prediction models were constructed, using a random forest regression algorithm, based on genus-level and species-level, respectively. The predictive efficacy of species-level microbial markers was higher, with the mean absolute error (MAE) of the saliva and feces prediction models being 0.30 day and 0.56 day, respectively. This finding suggests that using species-level microbial markers to determine the type and time since deposition (TsD) of body fluid stains has promising forensic value.

Fractures of the pelvic ring and acetabulum are caused by high-energy trauma, usually by traffic accidents. Acetabular fractures occur when a force drives the head of the femur against the acetabulum. As the prevalence of patients living with a total hip prosthesis (THR) increases, the chance of suffering periprosthetic acetabulum fractures also elevates. However, the injury threshold of forces resulting in a periprosthetic acetabular fracture is unknown. The study aimed to analyze the results of a dashboard injury on the acetabulum after total hip replacement through a head-on collision in an ex-vivo experiment. A cemented cup was implanted into hemipelves removed from cadavers, and a dashboard injury was simulated with an impact of a pendulum-like structure released from different heights. The impact energy increased until inflicting acetabular fracture. Eleven hemipelves were examined, of which five were male and six were female. The average force required to cause damage to the pelvis was 5852 N (3950-8386). Isolated acetabular component loosening was noticed with cement fracture in one case (at 5344 N force), acetabular cup loosening occurred combined with posterior column fracture in three cases (at 8386, 3950, 6295 N force), and acetabular cup loosening combined with acetabular floor fracture occurred in six cases (at 4305, 4573, 6531, 4707, 8174, 6117 N force). A combination of all three mechanisms occurred in one case: acetabular cup loosening, with posterior column and acetabular floor fracture at 5986 N force. The results of the ex-vivo experiment indicate that in a dashboard injury, at least around 4000 N force and 4 J impact energy is necessary to create a periacetabular fracture. The results suggest that a larger force is necessary for damage to occur in male pelvises: fractures occurred mostly below 5000 N force in female pelvises, while they occurred above 6000 N in most males.

The strong interaction between animals and humans in life makes the application of animal DNA analysis increasingly valuable. To determine the species origin of biological samples from crime scenes, exclude extraneous samples and focus on key evidence, and to identify meat adulteration incidents in food markets, two novel systems were developed to address the issue in this study. Both systems allow simultaneous identification of human beings (Homo sapiens) and 12 common animal species (Canis lupus familiaris, Felis catus, Gallus gallus, Anas platyrhynchos, Bos taurus, Ovis aries, Sus scrofa, Oryctolagus cuniculus, Equus caballus, Micropterus salmoides, Columba livia, Mus musculus) based on species-specific short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs), respectively. To validate the efficacy of the two systems in practical cases, we conducted a series of validation experiments on sensitivity, species specificity, mixture detection, and special case sample tests. Both were validated for the detection of blood, buccal swabs, tissue, and bloodstain samples. They showed good species specificity and are capable of identifying different species in mixed samples. They also have considerable detection rates for degraded samples after cooking and UV irradiation. Two systems provide more options for animal species identification based on the diversity and complexity of biological samples.

Forensic age estimation is of critical legal importance. This study aimed to assess the utility of ultrasonography (US) as an alternative, safe, non-invasive technique that could replace other roentgenographic modalities in forensic age estimation. Epiphyseal maturation staging of the upper and lower ends of the radius and ulna using US was conducted for 155 Egyptian juveniles and adolescents, showing a mean age of 15.8 ± 3.7 years. Above the age of 17, all females demonstrated complete epiphyseal closure of the proximal bone ends, and above the age of 18, the distal end of ulna was completely united. All males demonstrated complete epiphyseal union of the proximal ulna above 17 years, the proximal radius above 18 years, and distal ulnas above 20 years. A proposed model. [Formula: see text] using a novel total score assessing epiphyseal maturation of all forearm bones could significantly explain 85.6% of age variations, with very low error, where the predicted age deviates from the real age by approximately 1.0 to 1.2 years. We observed a substantial to near-perfect agreement between the estimated and chronological age (coefficients>0.879). The overall score has the highest accuracy in predicting the ages of 15, 16, 17, and 18 years (p < 0.001). Females showed accelerated epiphyseal maturation compared to males, and the proximal forearm bones approached full maturation before the distal ends. Using the proposed novel score assessing the proximal and distal ends of the ulna and radius through US offers a simple and radiation-free approach that could predict age with precision.

Sex determination is a critical step in identification. Scarce studies assessed the sexual dimorphism of specific lumbar vertebrae in Egyptians. This prospective study which enrolled 134 Egyptians assessed the sexual dimorphism of lumbar vertebrae using multi-slice computed tomography. At all levels, six vertebral measurements were investigated, including the upper end plate depth (EPDu), the lower end plate depth (EPDl), the upper end plate width (EPWu), the lower end plate width (EPWl), the anterior height of vertebral body (VBHa) and the posterior height of vertebral body (VBHp). The males exhibited significantly greater measurements than females, and EPDu, EPDl, EPWu, and EPWl of L1, EPDl of L2, EPWu of L3, and EPWl of L4 were the best individual sex predictors. We introduced five sex-predicting models showing exceptional area under curves ≥ 0.9. The models incorporating L1 and L2 measurements showed the highest R² of 0.791 and 0.801, respectively: Log probability of male sex=-51.524 + (5.878 x EPDu L1) + (4.383 x EPWl L1) + (4.309 x VBHp L1) and = -43.971 + (3.057 x EPDu L2) + (3.324 x EPDl L2) + (5.466 x EPWu L2) + (-10.867 x VBHa L2) + (9.699 x VBHp L2). Despite the significant correlations between the age and various measurements at different vertebral levels, lumbar vertebral bodies did not undergo uniform geometric changes with age; instead, specific regions and aspects of vertebral morphology change in distinct, sex-specific ways. We recommend validating the proposed models in different populations to generalize the obtained findings.