Forensic Toxicology最新文献

Purpose: Ethylene glycol (EG), a widely used industrial compound, has been implicated in accidental poisoning and homicide. Although the nephrotoxic mechanisms of EG are well characterized, its acute hepatotoxic potential remains underexplored. This study investigated histopathological and molecular alterations in the liver of rats following acute administration of EG. Possible dysfunction of an anti-oxidative pathway involving ferroptosis (glutathione peroxidase 4, Gpx4; solute carrier family 7 member 11, SLC7A11) is also examined.

Methods: Male rats (8-week-old, male) were orally administered EG (8 g/kg) and euthanized at 2 and 5 days post-exposure by an administration of an overdose of anesthetic (40 mg/kg sodium pentobarbital). Serological analysis was performed to assess liver function. Liver tissues were evaluated by histology, transmission electron microscopy, and transcriptome analysis.

Results: Serological findings indicated transient liver damage at 2 days post-exposure, followed by recovery at 5 days. Transmission electron microscopy revealed glycogen accumulation, corroborated by periodic acid-Schiff and periodic acid-methenamine silver staining. Histological analysis revealed an increased number of nucleoli, correlating with upregulation of ribosomal genes on microarray analysis, particularly at 5 days post-exposure. In addition, significant decreases in Gpx4 and SLC7A11 expression were observed in rat livers treated with EG and Huh-7 human hepatoma cells, suggesting reduced cellular antioxidative capacity as a contributing factor to transient liver damage.

Conclusions: These findings reveal a pathway underlying EG-induced transient liver damage and suggest a possible mechanism of recovery, thereby providing new insights into EG poisoning.

Purpose: In the present work, we report the combined use of hair and fly larvae samples as a valuable approach for obtaining additional toxicological evidence in cases of skeletonized corpses. In highly decomposed human remains, the absence of conventional biological specimens (e.g. blood, urine, and organs) requires alternative matrices to base the forensic investigation upon. However, it is challenging to find the most suitable medico-legal approach in these cases.

Methods: Hair and fly larvae samples were collected from two independent cases and processed by solid phase extraction using a similar procedure. Analyses were performed using liquid chromatography tandem mass spectrometry.

Results: Two anticonvulsants were found in the samples but in a different pattern: phenobarbital in case 1, and phenobarbital in association with phenytoin in case 2.

Conclusions: The results of this toxicological approach combining two different samples, hair and larvae, in addition to circumstantial and autopsy findings, proved to be paramount in the medico-legal assessment of the cases herein described, leading to the successful identification of the subjects by DNA analysis. We thus hope that the approach and findings reported in this work contribute to the growing entomotoxicology science and its applicability to real complex forensic cases, especially considering that, to the best of our knowledge, this is the first article describing the determination of phenytoin in insects for this purpose.

Purpose: In response to the Chinese government's regulation of etomidate and some of its analogs, illicit manufacturers have turned to novel structural analogs of etomidate to circumvent legal restrictions. This study aims to establish a qualitative and quantitative ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the detection of two emerging etomidate analogs-ABP-700 and 2,6-dichloro-3-fluoro-etomidate-and apply it to the analysis of hair samples from actual abusers.

Methods: Hair samples were washed, segmented, cryogenically ground, and extracted with methanol. For extraction, precisely 20 mg of homogenized hair sample was spiked with deuterated internal standard and subjected to methanol extraction with vortex mixing followed by centrifugation. The resulting supernatant was filtered through a 0.22 μm membrane filter prior to UPLC-MS/MS analysis.

Results: The method showed excellent quantitative linearity (r² > 0.99) over the range of 0.01-1 ng/mg. The limits of detection and quantification were 0.005 ng/mg and 0.01 ng/mg for both analytes. In authentic hair samples from suspected abusers, ABP-700 was detected at 0.11 ng/mg and 0.02 ng/mg, while 2,6-dichloro-3-fluoro-etomidate was quantified at 0.13 ng/mg. Concentrations in seized e-cigarette liquids were 22.6 µg/mg and 48.6 µg/mg, respectively.

Conclusions: This study establishes a validated analytical method for the simultaneous determination of ABP-700 and 2,6-dichloro-3-fluoro-etomidate in human hair matrices. To our knowledge, this is the first reported methodology enabling both identification and quantification of these novel etomidate analogs in hair samples, with successful application to forensic case samples.

Purpose: 3,4-Methylenedioxypyrovalerone (MDPV) is a potent psychostimulant substance endowed with addictive properties. As mammalian target of rapamycin (mTOR) mediates neuroadaptive changes responsible for development of addiction, the current study evaluated whether rapamycin, a potent and selective inhibitor of mTOR, prevents induction and expression of behavioral sensitization in mice treated with MDPV.

Methods: Locomotor sensitization was used as an animal model of early phase of addiction. C57BL/6JRj mice were treated with rapamycin before administration of MDPV during the induction phase of sensitization, or during the final 5 days of the withdrawal. Sensitization was assessed based on the measurement of locomotor activity after treatment with MDPV.

Results: Rapamycin administered on days 1-7 inhibited induction of sensitization characterized by increased horizontal and vertical locomotor activity on day 7 compared to day 1. Additionally, when given during the withdrawal from MDPV, rapamycin blocked expression of sensitization, defined as augmented response to MDPV on day 21 compared to day 1.

Conclusions: Abolishment of locomotor sensitization to MDPV by rapamycin suggests that neuroadaptive changes underlying this phenomenon are dependent on the mTOR signaling and warrants further research on possible application of mTOR inhibitors in treatment of addiction.

Purpose: This study aims to detail the identification, confirmation, and quantitation of lemborexant from clinical and postmortem specimens using a validated LC-MS/MS method. Additionally, it investigates the tissue distribution of lemborexant in several postmortem cases.

Methods: Lemborexant was isolated from the plasma of hospital patients or the postmortem specimens of forensic autopsy cases. Extraction from 0.1 mL or 0.1 g of sample was achieved by a modified QuEChERS protocol. The analysis was performed by liquid chromatography-tandem mass spectroscopy (LC-MS/MS). The quantitation method was validated in whole blood using internationally accepted parameters based on ANSI/ASB Standard 036. A total of 8 clinical samples and 13 forensic autopsy cases were analyzed by the validated method.

Results: In clinical cases, lemborexant concentrations in plasma ranged from 2.7 to 225 ng/mL. Lemborexant concentrations in the blood of forensic autopsy cases ranged from below the lower limit of quantitation (2 ng/mL) to 276 ng/mL. The highest postmortem concentrations were found in liver, adipose tissue, pancreas, and kidney. The method demonstrated high recovery rates and precision, with no significant matrix effects or interferences from other drugs.

Conclusions: The validated LC-MS/MS method proved effective for detecting and quantifying lemborexant in both clinical and forensic autopsy samples. The study highlights the importance of monitoring lemborexant and other dual orexin receptor antagonists (DORAs) in forensic investigations to understand their pharmacokinetics and potential toxicological effects.

Purpose: Methamphetamine (MA) is widely abused worldwide and has long been a major social concern. To provide basic information for comparing MA toxicokinetics in humans, we analyzed changes in the serum and urinary concentrations of MA and its metabolites in mice and compared the toxicokinetic profiles at the toxic dose with those at the therapeutic dose.

Methods: Mice were administered therapeutic (1.5 mg/kg) or toxic (15 mg/kg) doses and blood and urine samples were collected. The serum concentrations of MA and its metabolite amphetamine (AMP), as well as the urinary concentrations of MA and its metabolites-AMP, p-hydroxymethamphetamine (OHMA), p-hydroxyamphetamine (OHAMP), and norephedrine (NEP) -were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Results: The serum AUC_0-24 values for MA and AMP were approximately 16 and 41 times higher, respectively, in the toxic dose group than those in the therapeutic dose group. The urinary AMP and OHAMP excretion levels were approximately 3.6 and 2.2 times higher, respectively, in the toxic dose group. The urinary [AMP] / [MA] ratio at all collected points and [AMP] / [OHMA] ratio in the 0-24 h sample were significantly higher in the toxic than in the therapeutic dose group.

Conclusions: The results obtained from this study suggest that the metabolism of AMP to OHAMP and NEP was saturated during intoxication. Furthermore, the determination of whether a toxic dose had been administered within 24 h or after 24 h would be possible through a joint evaluation of the urinary [AMP] / [MA] and [AMP] / [OHMA] ratios.

Purpose: The cellular mechanisms underlying tolerance development to psychostimulant-induced neurotoxicity remain poorly understood. This study investigated these mechanisms using pyrrolidinophenone derivatives (PPs), potent amphetamine-type stimulants with strong dopaminergic activity and high cytotoxicity, aiming to establish a neuronal tolerance model and to explore adaptive processes relevant to substance use disorder.

Methods: Human SK-N-SH neuronal cells were chronically exposed to α-pyrrolidinooctanophenone (α-POP) to prepare the drug-resistant cell line, SH/POP. Transcriptomic profiling was performed to identify gene expression alterations associated with tolerance development.

Results: Cell sensitivity assay showed that SH/POP cells can survive at lethal concentrations (> 40 μM) of α-POP. RNA sequence analysis of the resistant cells identified alterations in 1,298 differentially expressed genes and the gene ontology analysis surmised an upregulation of calcium-binding-related genes. The development of α-POP resistance reduced the basal Ca²⁺ concentration and suppressed the caspase-3 activation elicited by the drug. Additionally, the development down-regulated the phosphorylation of a transcription factor cAMP response element-binding protein (CREB) and expressions of CREB-target genes, Fos proto-oncogene AP-1 transcription factor subunit and neurotensin. Furthermore, constitutive activation of endoplasmic reticulum stress responses and selective enhancement of trypsin-like proteasome activity in SH/POP cells were detected.

Conclusions: Resistance development of neuronal cells to PPs is ascribable to suppression of calcium-dependent apoptosis and CREB signaling, and constitutive activation of endoplasmic reticulum stress responses. The SH/POP cell line represents a novel in vitro model to study molecular adaptations to psychostimulant toxicity and provides insights into neuroadaptive mechanisms underlying substance use disorder.

Purpose: Hair testing for drugs has been used extensively in the forensic field since the 1990s, primarily in cases involving abused drugs such as methamphetamine and cocaine. Since the 2010s, its scope has expanded to include the detection of single dose of hypnotics, aiding in the investigation of serious crimes. This review presents essential knowledge for hair testing and the currently recommended analytical procedures and forensic applications.

Methods: A review of literature from the 1990s to the 2020s was conducted, focusing on analytical methods for detecting drugs in hair, drug concentrations in hair, and drug incorporation pathways.

Results: The characteristics of hair as a biological specimen include a longer detection window than other matrices such as urine and blood, as ingested drugs remain stable in hair over time. Significant differences in drug concentrations in hair are observed among substances, with several hypnotics, such as triazolam, having extremely low concentrations. Drugs are incorporated into hair primarily through two main pathways (the hair bulb and the upper dermis zone), with the dominant pathway depending on the drug's properties. In addition, hair dyeing and subsequent exposure to aqueous environments (e.g., daily hair washing) can significantly influence drug concentrations and their distribution patterns (concentration and hair region). These factors must be carefully considered in hair testing.

Conclusions: Hair testing is an effective means for proving drug intake and estimating use history, particularly in cases where there is a delay in reporting the incident. The interpretation of results must account for various factors, such as the chemical structures of drugs, incorporation pathways, and hair dyeing.