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Introduction: Due to its peculiar anatomy and physiology, the pericardial fluid is a biological matrix of particular interest in the forensic field. Despite this, the available literature has mainly focused on post-mortem biochemistry and forensic toxicology, while to the best of authors' knowledge post-mortem metabolomics has never been applied. Similarly, estimation of the time since death or post-mortem interval based on pericardial fluids has still rarely been attempted., Objectives: We applied a metabolomic approach based on 1 H nuclear magnetic resonance spectroscopy to ascertain the feasibility of monitoring post-mortem metabolite changes on human pericardial fluids with the aim of building a multivariate regression model for post-mortem interval estimation., Methods: Pericardial fluid samples were collected in 24 consecutive judicial autopsies, in a time frame ranging from 16 to 170 h after death. The only exclusion criterion was the quantitative and/or qualitative alteration of the sample. Two different extraction protocols were applied for low molecular weight metabolites selection, namely ultrafiltration and liquid-liquid extraction. Our metabolomic approach was based on the use of 1 H nuclear magnetic resonance and multivariate statistical data analysis., Results: The pericardial fluid samples treated with the two experimental protocols did not show significant differences in the distribution of the metabolites detected. A post-mortem interval estimation model based on 18 pericardial fluid samples was validated with an independent set of 6 samples, giving a prediction error of 33-34 h depending on the experimental protocol used. By narrowing the window to post-mortem intervals below 100 h, the prediction power of the model was significantly improved with an error of 13-15 h depending on the extraction protocol. Choline, glycine, ethanolamine, and hypoxanthine were the most relevant metabolites in the prediction model., Conclusion: The present study, although preliminary, shows that PF samples collected from a real forensic scenario represent a biofluid of interest for post-mortem metabolomics, with particular regard to the estimation of the time since death., (© 2023. The Author(s).)

Introduction: The estimation of post-mortem interval (PMI) remains a major challenge in forensic science. Most of the proposed approaches lack the reliability required to meet the rigorous forensic standards., Objectives: We applied 1 H NMR metabolomics to estimate PMI on ovine vitreous humour comparing the results with the actual scientific gold standard, namely vitreous potassium concentrations., Methods: Vitreous humour samples were collected in a time frame ranging from 6 to 86 h after death. Experiments were performed by using 1 H NMR metabolomics and ion capillary analysis. Data were submitted to multivariate statistical data analysis., Results: A multivariate calibration model was built to estimate PMI based on 47 vitreous humour samples. The model was validated with an independent test set of 24 samples, obtaining a prediction error on the entire range of 6.9 h for PMI < 24 h, 7.4 h for PMI between 24 and 48 h, and 10.3 h for PMI > 48 h. Time-related modifications of the 1 H NMR vitreous metabolomic profile could predict PMI better than potassium up to 48 h after death, whilst a combination of the two is better than the single approach for higher PMI estimation., Conclusion: The present study, although in a proof-of-concept animal model, shows that vitreous metabolomics can be a powerful tool to predict PMI providing a more accurate estimation compared to the widely studied approach based on vitreous potassium concentrations., (© 2023. The Author(s).)

Estimating the post-mortem interval is a fundamental, albeit challenging task in forensic sciences. To this aim, forensic practitioners need to assess post-mortem changes through a plethora of different methods, most of which are inherently qualitative, thus providing broad time intervals rather than precise determinations. This challenging problem is further complicated by the influence of environmental factors, which modify the temporal dynamics of post-mortem changes, sometimes in a rather unpredictable fashion. In this context, the search for quantitative and objective descriptors of post-mortem changes is highly demanded. In this study, we used computed tomography (CT) to assess the post-mortem anatomical modifications occurring in the time interval 0-4 days after death in the brain of four corpses. Our results show that fractal analysis of CT brain slices provides a set of quantitative descriptors able to map post-mortem changes over time throughout the whole brain. Although incapable of producing a direct estimation of the PMI, these descriptors could be used in combination with other more established methods to improve the accuracy and reliability of PMI determination., (© 2022. The Author(s).)

Using postmortem CT (PMCT), changes in the volume of the lateral cerebral ventricles (LCVs) and modifications of the radiodensity of cerebrospinal fluid (CSF) have been examined to identify a possible relationship between these changes and the time of death. Subsequent periodical CT scans termed "sequential scans" for ten corpses at known time of death were obtained, and a 3D segmentation of the entire LCV was carried out to measure its volume and radiodensity over time from ~ 5.5- h up to 273-h postmortem. A linear decrease of the LCV volume for all the cases was observed in the investigated time range, together with an overall logarithmic increase of radiodensity. Although a larger sampling should be performed to improve the result reliability, our finding suggests that the postmortem variation of CSF radiodensity can be a potentially useful tool in determining postmortem interval, a finding that is worthy of further investigation., (© 2021. The Author(s).)

Estimation of the post-mortem interval (PMI) remains a matter of concern in the forensic scenario. Traditional and novel approaches are not yet able to fully address this issue, which relies on complex biological phenomena triggered by death. For this purpose, eye compartments may be chosen for experimental studies because they are more resistant to post-mortem modifications. Vitreous humour, in particular, has been extensively investigated, with potassium concentration ([K + ]) being the marker that is better correlated with PMI estimation. Recently, a 1 H nuclear magnetic resonance (NMR) metabolomic approach based on aqueous humour (AH) from an animal model was proposed for PMI estimation, resulting in a robust and validated regression model. Here we studied the variation in [K + ] in the same experimental setup. [K + ] was determined through capillary ion analysis (CIA) and a regression analysis was performed. Moreover, it was investigated whether the PMI information related to potassium could improve the metabolome predictive power in estimating the PMI. Interestingly, we found that a part of the metabolomic profile is able to explain most of the information carried by potassium, suggesting that the rise in both potassium and metabolite concentrations relies on a similar biological mechanism. In the first 24-h PMI window, the AH metabolomic profile shows greater predictive power than [K + ] behaviour, suggesting its potential use as an additional tool for estimating the time since death.

Cadaveric rigidity-also referred to as rigor mortis-is a valuable source of information for estimating the time of death, which is a fundamental and challenging task in forensic sciences. Despite its relevance, assessing the level of cadaveric rigidity still relies on qualitative and often subjective observations, and the development of a more quantitative approach is highly demanded. In this context, ultrasound shear wave elastography (US SWE) appears to be a particularly well-suited technique for grading cadaveric rigidity, as it allows non-invasive quantification of muscle stiffness in terms of Young's modulus (E), which is a widely used parameter in tissue biomechanics. In this pilot study, we measured, for the first time in the literature, changes in the mechanical response of muscular tissues from 0 to 60 h post-mortem (hpm) using SWE, with the aim of investigating its applicability to forensic practice. For this purpose, 26 corpses were included in the study, and the muscle mechanical response was measured at random times in the 0-60 hpm range. Despite the preliminary nature of this study, our data indicate a promising role of SWE in the quantitative determination of cadaveric rigidity, which is still currently based on qualitative and semiquantitative methods. A more in-depth study is required to confirm SWE applicability in this field in order to overcome some of the inherent limitations of the present work, such as the rather low number of cases and the non-systematic approach of the measurements.

Methiopropamine is a structural analog of methamphetamine that is categorized as a novel psychoactive substance. It primarily acts as a norepinephrine-dopamine reuptake inhibitor and, secondarily, as a serotonin reuptake inhibitor. In humans, methiopropamine induces stimulation and alertness and increases focus and energy. However, significant side effects are reported, such as tachycardia, anxiety, panic attacks, perspiration, headache, and difficulty in breathing. To date, little data is available regarding its pharmacodynamic effects, thereby we aimed to investigate the acute in vivo effects induced by this drug on sensorimotor responses, body temperature, pain thresholds, motor activity, and cardiovascular and respiratory systems in CD-1 male mice. We selected a range of doses that correspond to the whole range of human reported use, in order to evaluate the threshold of adverse effects presentation. This study demonstrates that methiopropamine acts as a dopaminergic and noradrenergic stimulating drug and that the highest doses (10-30 mg/kg) impair the visual placing response, facilitate the acoustic and tactile response, induce hypothermia, increase mechanical and thermal analgesia, stimulate locomotor activity, induce motor stereotypies, and strongly affected cardiovascular and respiratory parameters, increasing heart rate, breath rate, and blood pressure but reducing oxygen saturation. On the contrary, lower doses do not show any of those effects. We hypothesize that there is a range of doses that do enhance performance but do not seem hazardous to users: this gap could induce the perception of safety and increase the abuser population.

The aim of this work was to characterise three non-toxic ammunition (NTA) from the GECO and Fiocchi brands, which are available in the Italian market. Characterisation was carried out by considering both the elemental chemical composition and morphology, using scanning electron microscopy coupled with energy-dispersive X-ray analysis (SEM-EDS). Particles were collected from both the cartridge cases and the shooters' hands after shooting tests. Six volunteers fired two shots for each ammunition. Several elements, such as aluminium, potassium, silicon, sulphur, titanium and zinc were found in gunshot residue (GSR) particles from different ammunition. We also studied the persistence of these types of GSR on the hands of the shooters in a range between 1 and 6 h after shooting. The GSR particles from the three NTA tested were found on the hands of shooters until 6 h after the shots. The characterisations undertaken in this work will be useful for specialists in forensic science and legal medicine to evaluate trace evidence from these new NTA in casework, as such formulations are in growth.

MDPV is a synthetic cathinone illegally marketed and consumed for its psychostimulant effects, which are similar to those produced by cocaine, amphetamines, and MDMA. Clinical reports indicate that MDPV produces euphoria, increases alertness, and at high doses causes agitation, psychosis, tachycardia and hypertension, hallucinations, delirium, hyperthermia, rhabdomyolysis, and even death. In rodents, MDPV reproduces the typical physiological effects of psychostimulant drugs, demonstrating greater potency than cocaine. Nevertheless, its role in aggressive behavior has been reported but not yet experimentally confirmed. Therefore, the aim of this study was to evaluate the effects of acute and repeated MDPV (0.01-10 mg/kg i.p.) administration on aggressive behavior in mice and to compare them with those of cocaine (0.01-10 mg/kg i.p.) administration. To this purpose, the resident-intruder test in isolated mice and the spontaneous and stimulated aggressiveness tests for group-housed mice were employed. The present study shows for the first time that MDPV enhances aggressive behavior and locomotion in mice with greater potency and efficacy than cocaine treatment. Moreover, the aggressive and locomotor responses are enhanced after repeated administration, indicating that a sensitization mechanism comes into play. These results, although from preclinical investigation, are suggestive that human MDPV intake could be a problem for public health and the criminal justice system. Thus, investigation by police officers and medical staff is needed to prevent interpersonal violence induced by the consumption of synthetic cathinones.

Forensic estimation of post-mortem interval relies on different methods, most of which, however, have practical limitations or provide insufficient results, still lacking a gold standard method. In order to better understand the phenomenon of rigor mortis and its applicability to the post-mortem interval estimation, we decided to use atomic force microscopy, a tool often employed to measure mechanical properties of adherent cells. Thus, we surgically removed skeletal muscle samples of three forensic cases from 0 to 120 h post-mortem and quantitatively evaluate two parameters: the Young's modulus (E), which gives information about the sample stiffness, and the hysteresis (H), which estimates the contribution of viscous forces. Despite being a preliminary study, the obtained results show that the temporal behavior of E well correlates with the expected evolution of rigor mortis between 0 and 48 h post-mortem, and then monotonically decreases over time. Unfortunately, it is strongly affected by inter-individual variability. However, we found that H provides measurable data along a time-dependent curve back to the starting point, and these data measured on different subjects collapse onto a single master curve, getting rid of the inter-individual variability. Although a larger sampling should be performed to improve the result reliability, this finding is strongly suggestive that the evaluation of rigor mortis should involve the measure of the nanoscale dissipative behavior of muscular tissues.

Methiopropamine (MPA) is a structural analogue of methamphetamine and belongs to the category of the novel psychoactive substances. To the best of our knowledge, no experimental study has been performed to evaluate the organ damage evoked by MPA administration in an animal model. Therefore, the main purpose of the present study was to investigate the histological changes in CD-1 male mice following the chronic administration of MPA. MPA-chronically treated mice showed myocardial damage with features consistent with repeated episodes of ischemia and a pattern of kidney damage and gastrointestinal ischemia, with ischemic-necrotic lesions of variable extent. In agreement with the analogies between MPA and methamphetamine, we link organ damage secondary to MPA administration to the vasoconstrictive effect exhibited by both compounds. Chronically MPA-treated mice did not show changes in body weight, food intake, thermoregulation, muscular strength and motor coordination in the accelerod test. However, acute MPA administration significantly increased their heart rate and promoted vasoconstriction, which were associated with the sudden death of a subset of animals (40% of all chronically treated mice). In conclusion, the present study demonstrates that MPA consumption could induce health hazards, highlighting the risk of sudden catastrophic events; therefore, clinicians should be aware of these data and consider MPA screening when no other drug is identified by a urine drug screen.

We performed external autopsies and examinations on two inmates who had committed suicide by hanging themselves with their underwear and using the window bars of their cells as ligature points after they had been placed in solitary confinement. In one case, the inmate had even been deprived of her clothing (with the exception to her underwear). Underwear has been rarely described as a means for self-harm and, to the best of our knowledge, no previous study has focused on cases of prison suicides committed using this garment, even though it is available to every inmate. The two cases were very similar; both inmates were young, physically aggressive and in their first week at a new facility; both had been affected by mental disorders, had been prescribed psychotropic medications and had histories of psychiatric hospitalisation. In each case, the psychiatric evaluations had highlighted significant suicidal risk. We discuss these two cases in an attempt to describe the complexity of and contradictions within the management of suicidal inmates at correctional facilities. We aim to propose new strategies and emphasise the need to introduce evidence-based standardised protocols over inhumane, ineffective and simplistic punitive measures in the management of these individuals.

When a sudden death occurs during a minor surgical intervention, it may require a careful and extensive postmortem investigation. One such case concerns a 61-year-old male patient affected by Peyronie's disease, who died suddenly during a corporoplasty procedure. Autopsy and histologic examinations showed a massive bilateral pulmonary micro-embolism brought on by periprostatic venous plexus thrombosis. The cause of death was attributed to intraoperative fatal pulmonary micro-embolism. Pulmonary thromboembolism is a major cause of death and is known to be a possible complication of surgery. Nevertheless, the periprostatic venous plexus is an unusual site of thrombosis, as it has been demonstrated that the majority of emboli originate in the legs. In this case, the embolism was massive and fatal and occurred during a minor surgical procedure, even though the patient was not at risk for venous thromboembolism, nor did he have a significant past medical history.

We report a case of a 6-year-old boy who had been living with his parents, both cocaine smokers, and who was urgently admitted to hospital for general distress. Upon examination, cocaine and cocaine metabolites were detected in hair and urine samples. These toxicological findings most likely indicate that the child had passively consumed the drug when living in a heavily contaminated environment.