International Journal of Legal Medicine最新文献

To date, lipophilic contrast agents mixed with oil, usually paraffin oil, are the most commonly used contrast agents in post-mortem computed tomography angiography (PMCTA). Iodine-based hydrophilic contrast media in combination with a water-soluble carrier, e.g. polyethylene glycol (PEG), are also common. However, their influence on different tissues and organs is poorly understood. In order to analyse the changes in the cadavers caused by the different carrier substances, we evaluated the effects of PEG 200 and oil on the different tissues and organs. Therefore, during a forensic autopsy, liquid femoral vein blood and samples of different organs and vessels were taken and preserved at room temperature in the two liquids mentioned. The condition of the samples was documented during the autopsy and 24, 48 and 72 h after preservation. Microscopic examination took place after 72 h. After 24 h, the samples placed in PEG 200 already showed a clear solidification of almost all structures. Crumbly blood agglomerates had formed in the previously liquid blood. In contrast, the samples stored in oil showed signs of classic cadaveric decomposition after 24 h, which increased with time. The microscopic and immunohistochemical evaluation of the samples stored in PEG showed a good diagnostic quality. The analysis of tissues stored in oil was much more difficult due to putrefaction. PEG and oil show significantly different effects on human tissues, mainly conservation and dehydration are affected. It is crucial to be aware of these differences in order to choose the most appropriate PMCTA method for each forensic case.

Bloodstains are crucial pieces of physical evidences found at violent crime scenes, providing valuable information for reconstructing forensic cases. However, there is limited data on how bloodstain lipidomes change over time after deposition. Hence, we deployed a high-throughput high-performance liquid chromatography-mass spectrometry (HPLC-MS) approach to construct lipidomic atlases of bloodstains, whole blood, plasma, and blood cells from 15 healthy adults. A time-course analysis was also performed on bloodstains deposited for up to 6 months at room temperature (~ 25°C). The molecular levels of 60 out of 400 detected lipid species differed dramatically between bloodstain and whole blood samples, with major disturbances observed in membrane glycerophospholipids. More than half of these lipids were prevalent in the cellular and plasmic fractions; approximately 27% and 10% of the identified lipids were uniquely derived from blood cells and plasma, respectively. Furthermore, a subset of 65 temporally dynamic lipid species arose across the 6-month room-temperature deposition period, with decreased triacylglycerols (TAGs) and increased lysophosphatidylcholines (LPCs) as representatives, accounting for approximately 8% of the total investigated lipids. The instability of lipids increased linearly with time, with the most variability observed in the first 10 days. This study sheds light on the impact of air-drying bloodstains on blood components at room temperature and provides a list of potential bloodstain lipid markers for determining the age of bloodstains.

Certificates of medical evidence are often used to aid the court in assessing the cause and severity of a victim's injuries. In cases with significant blood loss, the question whether the bleeding itself was life-threatening sometimes arises. To answer this, the volume classification of hypovolemic shock described in ATLS^® is commonly used as an aid, where a relative blood loss > 30% is considered life-threatening. In a recent study of deaths due to internal haemorrhage, many cases had a relative blood loss < 30%. However, many included cases had injuries which could presumably cause deaths via other mechanisms, making the interpretation uncertain. To resolve remaining ambiguity, we studied whether deaths due to isolated liver lacerations had a relative blood loss < 30%, a cause of death where the mechanism of death is presumably exsanguination only. Using the National Board of Forensic Medicine autopsy database, we identified all adult decedents, who had undergone a medico-legal autopsy 2001-2021 (n = 105 952), where liver laceration was registered as the underlying cause of death (n = 102). Cases where death resulted from a combination of also other injuries (n = 79), and cases that had received hospital care, were excluded (n = 4), leaving 19 cases. The proportion of internal haemorrhage to calculated total blood volume in these fatal pure exsanguinations ranged from 12 to 52%, with 63% of cases having a proportion < 30%. Our results lend further support to the claim that the volume classification of hypovolemic shock described in ATLS^® is inappropriate for assessing the degree of life-threatening haemorrhage in medico-legal cases.

Y-InDels (insertions/deletions) are genetic markers which are extremely understudied. It is unknown whether this type of markers can be utilized for genetic ancestry inference. We have developed an innovative Y chromosome ancestry inference system tailored for forensic applications. This panel amplifies 21 Y chromosome loci, encompassing Y-InDels and Y-SNPs (Single Nucleotide Polymorphism), utilizing the capillary electrophoresis (CE) platform. The system performed well at DNA concentrations greater than 0.125 ng/ul and produced accurate results at a 1:100 mixing ratio of male and female DNA. The Cumulative probability of matching (CPM) was between 0.95 and 0.97 in the experimental population. The system's efficacy in inferring ancestral origins was demonstrated through intercontinental population discrimination, revealing high discrimination power between African and East Asian populations. Population genetic analyses conducted on Han, Qiang and Hui populations in Southwest China, where the smallest F_ST value was 0.0002 between Han Chinese in Beijing (from 1000 Genomes Project) and Qiang Chinese from Sichuan (CQSC). Phylogenetic tree construction further illuminated distinct haplotypes among populations, with ethnically unique haplotypes observed in 34.6% of Hui and 7.1% of Qiang populations. K-fold cross-validation show the system's inference abilities at the intercontinental level. In addition, our investigations identified potential associations between the Y-InDel locus Y: 15,385,547 (GRCh37) and haplogroup R1a1a1b2a2- Z2124, as well as locus Y: 13,990,180 (GRCh37) and haplogroup F-M89. In conclusion, we have established a Y-chromosome inference system tailored for grassroots-level application, underscoring the value of incorporating Y-InDel markers in forensic analyses.

Introduction: Many aspects of tooth development have been documented, particularly in Caucasian populations. However, dental development has not been extensively studied in West Africa.

Objective: The present study was designed to provide information on the sequences of tooth calcification in West African black Senegalese children and to compare the results with those of other populations, notably the London Atlas.

Methods: A total of 556 orthopantomograms (OPGs) from 289 males and 266 females with a mean age of 11.34 ± 3.84 years were analyzed. Demirjian A-H staging was applied to record the stages of tooth development. Tables of tooth development stages for each tooth were generated separately for age cohorts and by sex. The most common stage of tooth formation (modal) was the characteristic age stage of development. Differences between boys and girls and between maxillary and mandibular teeth were also analyzed using chi-squares. Accuracy was assessed by comparing the age estimated by the Dental Development Atlas for this population (Cayor Atlas) and the London Atlas tooth with chronological age using the Bland-Altman test.

Results: There was no significant difference in tooth development between girls and boys, p > 0.05. Maxillary teeth had similar dental development to mandibular teeth, p > 0.05. The Pearson correlation test showed a strong correlation between chronological age and the age estimated by the Cayor atlas, p < 0.001. The Bland-Altman test also showed greater accuracy than the London Atlas.

Conclusion: These results show dental calcification sequences different from those of the London Atlas Tooth and the Witts Atlas (Atlas of Black South African Subjects).

Forensic age estimation is crucial in various legal and civil contexts, particularly in regions experiencing significant migration and inadequate birth registration systems. This study evaluates the applicability of the Vieth staging system for forensic age estimation in the living using MRI of the distal radial epiphysis. A retrospective analysis was conducted on 620 left wrist MRI scans from individuals aged 9.92 to 29.58 years. The study demonstrated high intra- and inter-observer agreement values (κ = 0.974 and κ = 0.961), confirming the method's reliability. Spearman's rank correlation analysis showed significant positive correlations between age and ossification stage for both sexes. The minimum ages observed for males were 9.92 years at stage 2, 15.00 years at stage 3, 15.00 years at stage 4, 17.00 years at stage 5, and 20.00 years at stage 6. For females, the minimum ages were 10.08 years at stage 2, 12.33 years at stage 3, 14.25 years at stage 4, 16.33 years at stage 5, and 18.42 years at stage 6. The study supports the applicability of the Vieth methodology for forensic age estimation in the living and suggests that MRI could be a non-invasive and potentially effective tool for determining critical age thresholds in forensic contexts. Further research is recommended to refine these methods and explore their applicability across different populations.

Accurate estimates of stature play an important role in the personal identification of unknown decedents, however a drawback in the application of many stature estimation equations is the need for known sex and population, the assignment of which can be challenging. Researchers have formulated equations for stature estimation that are neither population- nor sex-specific and thereof the aim of this study was to assess the applicability of these stature estimation equations proposed by Albanese et al.. (2016) (Albanese J, Tuck A, Gomes J, Cardoso HFV (2016) An alternative approach for estimating stature for long bones that is not population- or group-specific. Forensic Sci Int 259:59-68). The physiological length of the femur, condylar malleolar length of the tibia and a combination of these measurements, collected from Magnetic Resonance Imaging Scanograms of adult (20-60 years) White South African males (n = 30) and females (n = 44) were used to assess the accuracy of the Albanese et al. (Albanese J, Tuck A, Gomes J, Cardoso HFV (2016) An alternative approach for estimating stature for long bones that is not population- or group-specific. Forensic Sci Int 259:59-68). sex-specific and generic stature estimation equations. The stature estimates were compared with measured living stature (LSM), using paired t-tests. Results indicated that the Albanese et al. (Albanese J, Tuck A, Gomes J, Cardoso HFV (2016) An alternative approach for estimating stature for long bones that is not population- or group-specific. Forensic Sci Int 259:59-68). equations underestimated living stature by between 1.1 and 5.0 cm. These underestimations were significantly different between the LSM and the sex-specific estimates for females and the LSM and the generic estimates for males and the tibia for sex-specific equation. All stature estimates however fell in between two standard error of estimates for the sex-specific equations for males and the generic equations for the females. Although, the equations by Albanese et al. (Albanese J, Tuck A, Gomes J, Cardoso HFV (2016) An alternative approach for estimating stature for long bones that is not population- or group-specific. Forensic Sci Int 259:59-68). can be used to estimate stature in White South Africans in certain cases, the use of sex/population-specific equations remains the method of choice.

Y-chromosome short tandem repeats (Y-STRs) loci have significant research and application value in individual identification, parentage testing, kinship determination and genealogical DNA analysis due to their unique genetic characteristics. Currently, various commercial STR typing kits have used in forensic detection, which greatly promoting the scientific application of STR in criminal investigation and judicial trials. However, due to the complexity and specificity of biological samples, the special STR typing in the sample poses certain difficulties for the construction of DNA databases. In the current study, we explored the Y-STR genotyping in 4670 unrelated individuals using the Yfiler™ Platinum Kit, AGCU Y37 and AGCU Mini Y fluorescence detection kit in the Henan Province. We found that eight samples had inconsistent typing results. Among them, the genotyping inconsistency occurred twice for the Y_GATA_H4 locus, and once each for the loci DYS481, DYS444, DYS635, DYS437, DYS533 and DYS570. We sequenced and analyzed the inconsistent loci of these samples. Sequencing results indicated inconsistent typing due to low polymorphic repeat structures, Poly(N)n structures, single or multiple base insertions/deletions, and base transitions or transversions in flanking regions. Special attention should be paid to using the Y-STR database for family searches and paternity testing.

Background: Teeth are considered as hard tissue analogue to fingerprints, being unique to an individual. The enamel which forms the outer layer of the tooth is formed through a highly dynamic process in which ameloblasts lay down enamel rods in an undulating and intertwining path, which is reflected as a series of enamel rod pattern. The study of these patterns is termed as "Ameloglyphics". These patterns formed on the surface of enamel are called tooth prints each of which comprises the combination of different sub patterns, and are unique for every single tooth of an individual. This characteristic of uniqueness of the tooth print can serve as a significant biometric tool in forensic identification.

Objectives: To assess if ameloglyphics is an accurate and reliable method for forensic identification of individuals.

Methodology: Registration number- CRD42022338138. Data sources- Google Scholar, PubMed, Proquest, Europe PMC, Scopus. Study appraisal and synthesis methods- Studies were assessed for quality with the help of predetermined criteria which categorized the studies into high, medium and low quality with the help of JBI critical appraisal checklist for analytical cross-sectional studies using the key words such as Ameloglyphics, tooth prints and enamel rod end patterns.

Results: A total of 475 articles were obtained in the primary search from PubMed, Scopus, Europe PMC, ProQuest, and Google Scholar including gray literature for thorough search of related publications on Ameloglyphics. Following initial search of titles, 433 articles were excluded because they were not related to the objectives of the systematic review and 42 articles were further excluded after abstract reading and removal of duplicates. Finally,18 out of 22 articles which were fulfilling the inclusion criteria of the study were selected for qualitative synthesis after full-text screening and exclusion of review articles. The data obtained from the eighteen included studies were systematically reviewed but a meta-analysis could not be performed due to heterogeneity of the data.

Conclusion: Ameloglyphics is a relatively newer technique and a fair number of research are done on its application in identification of individuals. The results of the eighteen studies included in this review suggest that Ameloglyphicsis an useful adjunct for forensic identification.

Protocol registration: The study protocol can be accessed through the International Prospective Register of Systematic Reviews, the PROSPERO database with the following register number: CRD42022338138.