International Journal of Legal Medicine最新文献

Polymerase Chain Reaction (PCR) has transformed forensic DNA analysis but is still limited when dealing with compromised trace or inhibitor-containing samples. Nanotechnology has been integrated into nanoPCR (nanoparticle-assisted PCR) to overcome these obstacles. Nanomaterials improve PCR sensitivity, selectivity, and efficiency. Examples of these materials are semiconductor quantum dots and metal nanoparticles. They enhance DNA binding to primers, stabilize enzymes, and function as effective heat conductors, making accurate amplification possible even with tainted samples. The developments in nanoPCR have potential uses in forensics, as they allow for the more sensitive analysis of smaller, polluted, or deteriorated samples. Nevertheless, there are methodological and ethical issues. To provide credible and legitimate forensic evidence, rigorous validation and standardization of NanoPCR techniques are vital. The article addresses the relevant ethical and methodological aspects in forensic casework while examining the integration of nanotechnology into PCR.

In forensic neuropathology, the β-amyloid precursor protein (β-APP) immunostain is used to diagnose axonal injury (AI). The two most common aetiologies are traumatic (TAI) and ischaemic (vascular; VAI). We aimed to identify background characteristics and neuropathology findings that are suggestive of TAI, VAI, or no AI in neuropathologically examined medico-legal autopsy cases. The dataset comprised 166 cases from Finland over the period 2016-2023. The diagnosis of AI was based on β-APP stain (TAI, VAI, or no AI). Data on background characteristics and neuropathology findings were collected from cause-of-death investigation documents. Prevalence ratios were calculated for each variable to enable comparisons between the AI categories. The sample were 71.7% males; median age was 41 years (range 0-96). There were 26 cases with TAI, 44 with VAI, and 96 with no AI. The variables that showed statistical significance and had at least two-fold prevalence among TAI cases compared to VAI cases were: a documented recent injury; and presence of any extracranial/cranial/intracranial injury (including subdural haemorrhage [SDH], subarachnoid haemorrhage [SAH], intracerebral/ventricular haemorrhage [ICVH], or contusion) in autopsy or neuropathology. Correspondingly, variables indicating TAI over no AI were: a documented recent injury; postinjury survival ≥ 24 h; and presence of any extracranial/cranial/intracranial injury (including SDH, SAH, ICVH, contusion), herniation, or infarction in autopsy or neuropathology. Postinjury survival < 30 min was identified as an indicator of no AI over TAI. Finally, variables indicating VAI over no AI were: postinjury survival ≥ 24 h; lack of external injury to the head; and presence of SDH, brain oedema, herniation, or infarction in autopsy or neuropathology. In conclusion, we report several differences in characteristics and findings between cases diagnosed with TAI, VAI, and no AI. Our findings may help estimate the likelihood and potential aetiology of AI based on background characteristics and other neuropathology findings.

Pathology has benefited from the rapid progress of image-digitizing technology during the last decade. However, the application of digital whole slide images (WSI) in forensic pathology still needs to be improved. WSI validation is crucial to ensure diagnostic performance, at least equivalent to glass slides and light microscopy. The College of American Pathologists Pathology and Laboratory Quality Center recently updated internal digital pathology system validation recommendations. Following these guidelines, this pilot study aimed to validate the performance of a digital approach for forensic histopathological diagnosis. Six independent skilled forensic pathologists from different forensic medicine institutes evaluated 100 glass slides of forensic interest (80 stained with standard hematoxylin and eosin, 20 with special staining), including different organs and tissues, with light microscopy (Olympus BX51, Tokyo, Japan). Glass slides were scanned using the Aperio GT 450 DX Digital Slides Scanner (Leica Biosystems, Nussloch, Germany). After two wash-out weeks, forensic pathologists evaluated WSIs in front of a widescreen using computer devices with dedicated software (O3 viewer, O3 Enterprise, Zucchetti, Trieste, Italy). Side-by-side comparisons between diagnoses performed on tissue glass slides versus WSIs were above the threshold stated in the validation guidelines (mean concordance of 97.8%). CSUQ Version 3 questionnaire showed high satisfaction for all pathologists (mean result: 6.6/7). Our institutional digital forensic pathology system has been validated for practical casework application. This approach opens new scenarios in practical forensic casework investigations, such as sharing live histological ex-glass slides online, as well as educational and research perspectives, with improving impacts on the whole daily workflow.

Aortic regurgitation is a common valve disease and can be caused by delineated findings such as fenestrations or hardly discernible alterations of the aortic root geometry. Therefore, aortic regurgitation can be a challenging diagnosis during an autopsy. Cardiac surgeons, however, are confronted with comparable problems during surgery and have developed a refined knowledge of the anatomy of the aortic root including its geometry. Transferring this knowledge from the operating room to the dissection would further complement the panel of postmortem diagnostic tools. To foster translation of the clinical anatomy, the present study assessed the impact of postmortem peculiarities (i.e. myocardial rigor mortis, putrefaction) that might influence aortic root geometry. The aortic root geometry was described by aortic perimeters (basal, sinus, sino-tubular junction, and ascending aorta), effective height (distance from the cusp's free margin to its nadir), geometric height (cusp height), commissural height (distance from the base of an interleaflet triangle to the end of a commissure), and length of the ascending aorta. Data from 140 cases were analyzed (linear regression, comparative testing). Myocardial rigor mortis was associated with smaller basal rings. Weak positive correlations between the duration of the postmortem interval and aortic root dimensions were observed. In summary, postmortem peculiarities, especially the myocardial cadaveric rigidity, influence postmortem aortic root geometry. Despite these circumstances, the current study demonstrates that aortic root geometric assessment, including effective height, is feasible in a postmortem setting. Further studies are needed to elaborate on aortic root geometry as a diagnostic tool in a necropsy setting.

In response to a recent case report published in the International Journal of Legal Medicine entitled "A case of hemorrhage at the junctions of the posterior intercostal arteries-a vital sign?", we wish to corroborate the findings of periadventitial hemorrhages at the junctions of the posterior intercostal arteries in cases of suicidal hanging and to reveal two other novel aortic lesions associated with hanging. In our ongoing prospective study, we identified six cases of aortic intimal ruptures among 257 suicidal hanging deaths, along with the novel observation of subintimal hemorrhages-both of which have not been previously documented in the forensic literature. Our findings suggest that the complex anatomy of the aorta and surrounding structures may increase the vulnerability of vascular structures during hanging, particularly under conditions of complete suspension. We propose that reported aortic lesions may serve as significant morphological indicators of hanging, thereby enriching its medicolegal investigation. To establish the diagnostic relevance of these findings, further prospective autopsy studies with larger sample sizes are warranted.

The diagnosis of abusive head trauma (AbHT) in children is a challenging one that needs to be differentiated from natural disease and accidental head injury (AcHT). There is increasing evidence from the Neuroradiology field showing spinal cord injury in children subject to AbHT, which has, so far, been poorly investigated pathologically. In this study we retrospectively reviewed the forensic records of 110 paediatric head injury cases over an eight-year-period. The records included detailed circumstances of death and clinical history alongside neuropathology, ophthalmic pathology and osteo-articular pathology. Based on the final multidisciplinary agreement, the 110 case were grouped into AbHT (n = 40), AcHT (n = 9), not clearly accidental or abusive ("undetermined" (UHT) n = 8) and non-traumatic brain injury (NTBI, n = 53). The spinal cord pathology present within each group was compared. Spinal subdural haematoma (SDH) was present in 71% of AbHT and 50% of AcHT cases and were located predominantly at the thoracolumbar level. In AbHT cases without spinal SDH, the suspected mechanism of injury was that of head impact rather than shaking, whilst cases of AcHT with spinal SDH were associated with direct trauma to the spinal cord. Injury of spinal nerve roots in AbHT was almost three times that seen in the accidental head injury group (58% vs. 17%). The study shows that pathological examination of the spinal cord and spinal nerve roots is of high value in investigating AHT and may help in differentiating AbHT from AcHT.

The authors present a case involving a 37-year-old woman discovered in an operating freezer. Suicide hypothesis has been considered from the beginning. Due to the exceptional scene circumstances, a forensic autopsy was performed. Apart from some non-specific hypothermia and asphyxia signs, the autopsy revealed several skull fractures, prompting extensive anatomopathological and histological analyses. These analyses confirmed the fractures origin and determined whether they were ante-mortem or post-mortem, thus ruling out the possibility of a criminal act disguised as suicide. The authors also describe the challenges in determining the cause of death, particularly the issues related to the post-mortem diagnosis of lethal hypothermia and asphyxia. This case is the first in the literature to describe suicide by exposure to cold in a confined environment. It highlights the importance of close collaboration between forensic pathologists, histologists, toxicologists, and police investigators to answer judicial inquiries.

The diagnostic use of the diatom test for drowning has been under investigation for more than a century. Despite continuing research, its true usefulness remains controversial and under debate. Data regarding the extent to which diatoms can penetrate the lungs and other organs of drowning victims are conflicting; similar discrepancies exist as to the presence of diatoms in the organs of living individuals; and as to the occurrence of postmortem (PM) contamination. To shed light on current understanding, we conducted a systematic review based on the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) to investigate how the presence of diatoms PM may be interpreted during medico-legal investigations of drowning. Following sequential screening of records based on our predetermined eligibility criteria, we assessed scientific evidence and risk of bias by use of the SPICOT framework. A total of 17 studies reporting diatom concentrations in victims of drowning, in non-drowned controls, and in non-drowned immersed controls were eligible for this review. Our findings suggest that diatom testing may be of use in medico-legal investigations, although its evidentiary value remains uncertain because both quantitative and qualitative results from the literature are insufficiently comparable. Variations in study design, methodology and reporting approach also fail to provide a comprehensive understanding of the significance of false-positive and false-negative results. Further research is warranted on antemortem and PM contamination, and on standardized autopsy and laboratory procedures, as well as on automated and certified diatom-counting and -identification systems. Moreover, since diatom taxonomy lies outside the specialty of forensic medicine, we underscore that collaboration with expert diatomologists is necessary for analysis and interpretation. Until these issues are adequately addressed, the evidentiary value of diatom testing for the diagnosis of drowning will continue to remain elusive and contentious.

In July 2023, an in-house forensic neuropathology consultation pilot was established at the Helsinki office of the Forensic Medicine Unit, Finnish Institute for Health and Welfare. This offered an alternative to the previous practice of full outsourcing to a hospital neuropathology department. This paper aims to introduce the first year experiences of the pilot. The in-house consultant team comprised two forensic pathologists with special training in neuropathology. In-house consultations were offered for medico-legal autopsy cases with traumatic brain injury (TBI) and hypoxic-ischaemic encephalopathy. The in-house histology laboratory participated in the pilot, implementing beta-amyloid precursor protein (β-APP) stain at the end of the pilot year. An electronic database was also developed for data collection and reporting. The characteristics, costs, and duration of the first 25 consultation cases were reviewed. The cases involved mostly male decedents (84.0%) with TBI (84.0%). The median total cost of a pilot case was €624, which was substantially lower compared to the previous outsourced practice (€1013 per case + €38/84 for each microscope slide with special/immunohistochemical stain, respectively). After the implementation of β-APP stain into the in-house laboratory service, the median total cost of a pilot case was reduced further to €94. The median duration of an in-house consultation was 2.3 months. Thanks to a favourable in-house atmosphere, the first year experiences are encouraging. While the costs of the in-house consultation practice appear to be markedly lower than those of an external provider, both alternatives should be available for cases where sufficient expertise cannot be found in-house.

The ForenSeq™ DNA Signature Prep kit has not been thoroughly tested with crude buccal swab lysates in large-scale population studies using massively parallel sequencing (MPS). Commonly used lysis buffers for swabs intending to undergo direct polymerase chain reaction (PCR) are SwabSolution™ and STR GO! Lysis Buffers, and these have been successfully used to generate population data using capillary electrophoresis (CE) systems. In this study, we investigated the performance and optimisation of SwabSolution™ and STR GO! lysates with the ForenSeq™ DNA Signature Prep workflow and addressed the challenge of failed MPS profiles in initial trials. To mitigate PCR inhibition in SwabSolution™ lysates, three optimisation methods were evaluated: dilution of lysates, addition of 5X AmpSolution^® reagent, and purification with magnetic beads. For STR GO! lysates, we explored spin-column purification using the QIAamp^® DNA Investigator kit, magnetic bead purification, and a pH adjustment with 1 M hydrochloric acid. Our findings indicated that the addition of 5X AmpSolution^® was effective for overcoming PCR inhibition in SwabSolution™ lysates, thereby maintaining a direct PCR approach. Spin-column purification, however, is recommended for STR GO! lysates to minimise MPS profile failure rates. These improvements enhance first-time success rates of crude swab lysates, and reduce the need for repeat sampling and re-sequencing, making the workflow more suitable for large-scale population studies in forensic laboratories.