Detection of Chemical Weapon Nerve Agents in Bone by Liquid Chromatography-Mass Spectrometry.

A recently proposed model for the incorporation of xenobiotics of forensic interest into the human skeleton suggests nerve agent metabolites may incorporate into bone at relatively elevated concentrations based on their unique chemical properties. To test the hypothesis that nerve agent metabolites interact with bone, methods for the extraction, isolation and semi-quantitative detection of nerve agent metabolites (MPA, EMPA, IMPA, iBuMPA, CMPA and PMPA, corresponding to the nerve agents VX, Russian VX, sarin, cyclosarin and soman, respectively) from osseous tissue were developed using liquid chromatography-mass spectrometry with both quadrupole time-of-flight and triple quadrupole (QqQ) instruments. The optimized methods were validated on the QqQ instrument. Despite high ion suppression, the achieved limits of detection (5-20 pg/g for four analytes; 350 pg/g for the fifth analyte) were lower than many of those published for the same analytes in other biomatrices, including serum and urine. These methods were tested on the skeletal remains of minipigs exposed to the chemical weapon VX in vivo. The VX metabolite was detected in multiple minipig bone samples; to the authors' knowledge, this is the first time in vivo nerve agent exposure has been detected from bone. Further, detected concentrations and diaphyseal-to-epiphyseal area count ratios reflect animal exposure history. Although the results are limited, they are promising, indicating that nerve agent metabolites may interact with bone as a pharmacokinetic compartment and can be extracted from bone postmortem. Additional studies, assessing the effects of different agents, exposure pathways and taphonomic variables, are needed; however, these results suggest the method may be used with human bone to detect use of chemical weapons from postmortem biomatrices even well after a suspected attack. More general implications for both nerve agent toxicology and skeletal toxicology are also discussed.

Early Signs of Fracture Repair in the Human Rib Cage: Implications for Forensic Casework.

The decomposed body of a woman discovered beneath a collapsed structure was examined at the C.A. Pound Human Identification Laboratory. Despite a mix of rib fractures with and without indications of healing, it is most likely that all fractures occurred as a result of a single, compressive event. Signs of intramembranous, and possibly direct, fracture healing at the incomplete fractures without signs of endochondral ossification at the complete fractures suggest the individual died very shortly-but not immediately-after injury. Given the case circumstances, the findings inform immediate cause of death. This case study highlights that differential healing as a result of a single event is possible. Further, it illustrates the importance of careful examination of micro-discontinuities/cracks that can occur in association with major fractures. Fracture healing and dating data are discussed, as is the possible need for critical evaluation of the antemortem/perimortem boundary.

The current state and future directions of skeletal toxicology: Forensic and humanitarian implications of a proposed model for the in vivo incorporation of drugs into the human skeleton.

At present, the inability to meaningfully and reliably conduct toxicological testing on human skeletal material represents a significant gap in forensic practice, especially in a time when the U.S. has declared opioid use a public health emergency and chemical weapon use in both mass and isolated attacks is prevalent in international news. In recent years, an increasing number of case studies and experiments have been published in an attempt to fill this knowledge gap. These papers are reviewed, and their valuable and pertinent findings discussed. However, the lack of an established model for the incorporation of drugs of forensic interest into bone has limited interpretation of results and delayed adoption of skeletal toxicology methods into accepted forensic practice. A model for the in vivo incorporation of drugs of forensic interest into bone tissue is proposed herein. This model is derived from known pathways for in vivo incorporation of compounds and analytes not of traditional forensic interest into bone tissue and is based on principles of ionic exchange, adsorption, and substitution. Testing and understanding these pathways may better guide skeletal toxicological experimentation, resulting in methods more tailored to human bone as a unique, largely inorganic matrix, as well as in increased interpretability of results. Further, the proposed model suggests possible novel applications for the field of skeletal toxicology on the humanitarian stage. Indeed, based on their chemical properties, chemical weapon nerve agents should be investigated as xenobiotics that may incorporate into the human skeleton at relatively elevated levels. If nerve agents can be isolated from skeletal remains, the field of skeletal toxicology may be able to offer important contributions to human rights investigations of mass graves.

Ancestral Variation in Orbital Rim Shape: A Three-Dimensional Pilot Study.

Traditional nonmetric methods of ancestry assessment posit orbital rim shape varies among ancestral groups. This pilot study uses morphometric analysis of 3D orbital variation to test discrimination among individuals of primarily European, African, and Asian ancestry. Although the size and nature of the sample analyzed limit inferences for other samples, principal components analysis suggests ancestry has a significant effect on rim shape (p = 2.93e-04). European orbits display more marked folding of the orbit in the sagittal plane than either African or Asian orbits, while the lateral margin of African orbits lies further posterior relative to the medial margin when compared to Asian orbits. The findings suggest curviplanar relationships are the most ancestrally informative aspect of orbital rim shape; these relationships may be distorted by perspective based on orientation of the skull relative to the viewer in traditional nonmetric analyses. Additional studies on geometric morphometric approaches to ancestry assessment are therefore warranted.