International Journal of Legal Medicine最新文献

Aim and objectives: In forensic age estimation e.g. for judicial proceedings surpassed age thresholds can be legally relevant. To examine age related differences in skeletal development the recommendations by the Study Group on Forensic Age Diagnostics (AGFAD) are based on ionizing radiation (among others orthopantomograms, plain x-rays of the hand). Vieth et al. and Ottow et al. proposed MRI-classifications for the epiphyseal-diaphyseal fusion of the knee joint to define different age groups in healthy volunteers. The aim of the present study was to directly compare these two classifications in a large German patient population.

Materials and methods: MRI of the knee joint of 900 patients (405 female, 495 male) from 10 to 28 years of age were retrospectively analyzed. Acquired T1-weighted turbo spin-echo sequence (TSE) and T2-weighted sequence with fat suppression by turbo inversion recovery magnitude (TIRM) were analyzed for the two classifications. The different bony fusion stages of the two classifications were determined and the corresponding chronological ages assigned. Differences between the sexes were analyzed. Intra- and inter-observer agreements were determined using Cohen's kappa.

Results: With the classification of Ottow et al. it was possible to determine completion of the 18th and 21st year of life in both sexes. With the classification of Vieth et al. completion of the 18th year of life for female patients and the 14th and 21st year of life in both sexes could be determined. The intra- and inter-observer agreement levels were very good (κ > 0.82).

Conclusion: In the large German patient cohort of this study it was possible to determine the 18th year of life with for both sexes with the classification of Ottow et al. and for female patients with the classification of Vieth et al. It was also possible to determine the 21st year of life for all bones with the classification of Ottow et al. and for the distal femur with the classification of Vieth et al.

Thanks to technical progress and the availability of virtual data, sex estimation methods as part of a biological profile are undergoing an inevitable evolution. Further reductions in subjectivity, but potentially also in measurement errors, can be brought by approaches that automate the extraction of variables. Such automatization also significantly accelerates and facilitates the specialist's work. The aim of this study is (1) to apply a previously proposed algorithm (Kuchař et al. 2021) to automatically extract 10 variables used for the DSP2 sex estimation method, and (2) to test the robustness of the new automatic approach in a current heterogeneous population. For the first aim, we used a sample of 240 3D scans of pelvic bones from the same individuals, which were measured manually for the DSP database. For the second aim a sample of 108 pelvic bones from the New Mexico Decedent Image Database was used. The results showed high agreement between automatic and manual measurements with rTEM below 5% for all dimensions except two. The accuracy of final sex estimates based on all 10 variables was excellent (error rate 0.3%). However, we observed a higher number of undetermined individuals in the Portuguese sample (25% of males) and the New Mexican sample (36.5% of females). In conclusion, the procedure for automatic dimension extraction was successfully applied both to a different type of data and to a heterogeneous population.

Objective: This study aims to evaluate the relationship between Total Body Score (TBS) and Accumulated Degree-Days (ADD) for estimating postmortem interval (PMI) using the decomposition quantification system by Megyesi et al. (Megyesi MS, Nawrocki SP, Haskell NH (2005) Using Accumulated Degree-Days to Estimate the Postmortem Interval from Decomposed Human Remains. J Forensic Sci 50:1-9. https://doi.org/10.1520/jfs2004017 ).

Design: A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The methodological quality and risk of bias were assessed using the QUADAS-2 scoring system. Statical tests, including I² for heterogeneity assessment and subgroup analysis comparing human and pig proxies across different decomposition stages, were performed for meta-analysis.

Results: The search identified 25 studies that underwent qualitative evaluation, all of which were included for quantitative analysis. The findings indicate that the TBS formula tends to overestimate ADD with a moderate mean difference of 0.5758 overall. Specifically, in pigs, ADD is overestimated significantly (1.1128), while there is a slight underestimation in humans (-0.0038). Across decomposition stages, fresh body (0.0066) and early decomposition (0.0338) show an insignificant overestimation, whereas advanced decomposition reveals a slight underestimation (-0.3378) and skeletonization indicates a substantial overestimation (1.6583).

Conclusions: The relationship between TBS and ADD demonstrates high accuracy in humans during early decomposition stages, without differences in statistical significance. However, its accuracy diminishes as decomposition progresses, potentially leading to an overestimation of PMI.

Facial approximation is a technique that involves constructing the facial muscles and applying a suitable facial soft tissue depth (FSTD) dataset. To date, several FSTD studies have been conducted for varying population groups. This study aims to establish a FSTD dataset of an adult Greek population sample for the first time. The facial depths of subjects were measured on 100 head CT scans of 50 male and 50 female subjects aged from 18 to 99. The 3D head and skull models of subjects were segmented in Amira 6.1 by using histogram method. FSTDs were measured at 22 cranial landmarks (5 mid-sagittal, 17 bilateral). The FSTD dataset was generated by considering the age and sex of subjects. The impact of age and sex on the FSTD was limited. Slight inter-population depth variations were reported. Facial asymmetry calculated between the bilateral landmarks was insignificant for both male and female subjects.

The PowerPlex^® 35GY System (Promega, USA) is an advanced eight-dye multiplex STR kit, incorporating twenty-three autosomal STR loci, eleven Y chromosome STR loci, one sex determining marker Amelogenin, and two quality indicators. This multiplex system includes 20 CODIS loci and up to 15 mini-STR loci with sizing values less than 250 bases. In this study, validation for PowerPlex^® 35GY System was conducted following the guidelines of SWGDAM, encompassing sensitivity, precision, accuracy, concordance, species specificity, stutter, mixture, stability, and degraded DNA. The results from experiments demonstrated that the PowerPlex^® 35GY System could effectively amplify DNA samples, with complete allele detection achieved at 125 pg. Moreover, over 90% of alleles from minor contributors were detected at a mixed ratio of 1:4. Additionally, the system was found to yield full profiles even in the presence of hematin, humic acid, and indigo. The PowerPlex^® 35GY System demonstrated superior performance in the sensitivity and degraded DNA studies compared to a six-dye STR kit. Hence, it is evident that the PowerPlex^® 35GY System is well-suited for forensic practice, whether in casework or for database samples. These findings provide strong support for the efficacy and reliability of the PowerPlex^® 35GY System in forensic applications.

Sudden infant death syndrome (SIDS) is still the leading cause of death for newborns in developed countries. The pathophysiological mechanisms have not been fully clarified, but in some of SIDS cases variants of genes associated with inherited cardiac conditions are found. In this study, an analysis of SCD-related genes was performed to determine the prevalence of rare pathogenic (P) or likely pathogenic (LP) variants that could provide an unambiguous explanation for the fatal event. A cohort of 76 SIDS cases underwent Next-Generation Sequencing (NGS) analysis with a custom panel of SCD-related genes. Rare variants were classified according to the guidelines provided by the American College of Medical Genetics and Genomics (ACMG) and the specifications of the ClinGen association. Post-mortem genetic testing identified 50 (65.8%) carriers of at least one variant in SCD genes. 104 rare genetic variants were found, 65.4% in genes encoding structural proteins. Only 4 out of 76 cases (5.3%) hosted at least a P or LP variant found in genes with structural or structural/arrhythmogenic functions (SLC22A5, SCN5A, MYL3and TTN). 99 variants were classified as of uncertain significance (VUS). The difference in the distribution of variants between gene groups by function was not statistically significant (chi square, p = 0,219). Despite this, most of the variants concerned structural genes that were supposed to have a close interaction with ion channels, thus providing an explanation for the arrhythmic event. Segregation analysis, reclassification of VUS variants and identification of new associated genes could clarify the implications of the current findings.

Investigation of the biological sex of human remains is a crucial aspect of physical anthropology. However, due to varying states of skeletal preservation, multiple approaches and structures of interest need to be explored. This research aims to investigate the potential use of distances between bifrontal breadth (FMB), infraorbital foramina distance (IOD), nasal breadth (NLB), inter-canine width (ICD), and distance between mental foramina (MFD) for combined sex prediction through traditional statistical methods and through open-access machine-learning tools. Ethical approval was obtained from the ethics committee, and out of 100 cone beam computed tomography (CBCT) scans, 54 individuals were selected with all the points visible. Ten extra exams were chosen to test the predictors developed from the learning sample. Descriptive analysis of measurements, standard deviation, and standard error were obtained. T-student and Mann-Whitney tests were utilized to assess the sex differences within the variables. A logistic regression equation was developed and tested for the investigation of the biological sex as well as decision trees, random forest, and artificial neural networks machine-learning models. The results indicate a strong correlation between the measurements and the sex of individuals. When combined, the measurements were able to predict sex using a regression formula or machine learning based models which can be exported and added to software or webpages. Considering the methods, the estimations showed an accuracy rate superior to 80% for males and 82% for females. All skulls in the test sample were accurately predicted by both statistical and machine-learning models. This exploratory study successfully established a correlation between facial measurements and the sex of individuals, validating the prediction potential of machine learning, augmenting the investigative tools available to experts with a high differentiation potential.

The analysis of traces of injuries can be difficult in cases of charred human remains since the alteration and fragmentation are high. The aim of this study is to explore the use of X-Ray Fluorescence (XRF) technique as a screening tool for detecting and analyzing gunshot residues (GSR) on cremated and highly fragmented materials, as it is a technique that allows for fast qualitative investigations without altering the sample or requiring sample preparation. The study was carried out on two steps: firstly, on completed skeletonized bones to verify if GSR survive to burning; secondly, we considered a more realistic situation, in which soft tissues were present before the shooting. To this aim, nine adult bovine ribs, four retaining soft tissue, five completely skeletonized, were subjected to a shooting test using two types of 9 mm projectiles (jacketed and unjacketed bullets). The ribs were then burnt until complete calcination in an electric furnace. The entry wound of each rib was analyzed using XRF, revealing traces of GSR. The XRF analysis showed that all samples, except for one, contain Pb and/or Sb near the lesion. Furthermore, the samples hit by unjacketed bullets had a more significant presence of Pb in macroscopic yellow areas, which persisted when moving away from the gunshot. These findings could pave the way for the use of XRF technology, mostly when a fast and immediate scan must be done on osteologic materials by a conservative method.

This study explores the reliability of four established legal age threshold estimation approaches in a Croatian sample. We applied Haavikko stages, Demirjian stages, Olze's third molar eruption stages, and second and third molar maturity indices measurement in 593 orthopantomograms of Croatian children and adolescents aged 11.00-20.99 years old. The left mandibular second and third molar were assessed. Logistic regression analysis was conducted to test the significance of predictive variables. Logistic Receiver operating characteristic (ROC) curves were performed to evaluate the classification ability of variables for estimating 14- and 16-year-old thresholds. The areas under the ROC curve (AUC), accuracy (Acc), sensitivity (Se), specificity (Sp), Positive Likelihood Ratio (LR +), Negative Likelihood Ratio (LR-), and Bayes post-test probability (Bayes PTP) were calculated to evaluate classification performance. Results suggest that the combination of I_2M&I_3M is the best classifier for the 14-year-old threshold (AUC = 0.879); for males alone, I_2M is an even better classifier (AUC = 0.881). The highest Acc 80.1% (95%CI, 75.9%-83.9%), Bayes PTP 86.5% (95%CI, 82.8%-89.7%) and Sp 88.9% (95%CI, 83.0%-93.3%) were by I_3M < 0.81 & I_2M < 0.03 in total samples; the highest Acc 86.1% (80.6%- 90.6%), Bayes PTP 87.2% (95%CI, 81.7%- 91.4%) and Sp 87.8% (95%CI, 78.2%- 94.3%) were by I_2M < 0.01 in males, Acc of Haavikko Ac and Demirjian H stage in second molar is very close with slightly lower Bayes PTP and Sp. I_3M is a good classifier for 16-year-old threshold (AUC = 0.889). The cut-off value I_3M < 0.34 can be used to classify the 16-year-old threshold with Acc of 80.6% (95%CI, 77.2%-83.7%), Sp of 83.4% (95%CI, 79.0%-87.3%), and 81.7% (95%CI, 78.4%-84.8%) Bayes PTP. In conclusion, to classify the 14-year-old threshold, a pair of cut-off values I_3M < 0.81 & I_2M < 0.03 can be used in Croatian females; I_2M < 0.01, Demirjian H stage, Haavikko Ac stage in second molar, and the pair I_3M < 0.81 & I_2M < 0.03 can all be used in Croatian males. I_3M < 0.34 can classify the 16-year-old threshold in Croatian populations.

STR loci localized on the X chromosome provide information additional to the autosomal markers routinely analyzed in forensic genetics, integrating genetic systems as Y-STRs and mitochondrial DNA in the investigation of complex kinship scenarios and mass disaster cases.In this study we genotyped 12 X-STR loci in 251 male samples from four populations of Namibia in southern Africa using the Investigator Argus X-12 kit (Qiagen, Hilden, Germany). Forensic efficiency parameters indicated high power of discrimination in the considered populations. As part of our investigation, we highlighted partial linkage associations between loci within known linkage groups (LGs) and identified several occurrences of previously unreported out-of-ladder (OL) alleles.Genetic distances between the Namibian populations here investigated and other African (Eritrea, Ethiopia, Somalia, Guinea, Cape Verde) and non-African (Germany, China, Philippines) populations using loci grouped in LGs mirrored their biogeographical distribution differently for each linkage group. Haplotype sharing within each LG revealed a high degree of population-specific types, hinting to the potential of these markers for ancestry applications.These results highlight the importance to produce specific and freely available population databases especially for multi-ethnic countries. This novel dataset is expected to be of interest for population studies that need an accessible reference dataset of African regions not currently well represented, as well as possible relevance for forensic applications focusing on the biogeographic origin of samples.