Development and intrapuparial characterization of Peckia (Euboettcheria) collusor (Curran and Walley, 1934) (Diptera: Sarcophagidae) for application in forensic entomology.

The family Sarcophagidae is very diverse in Brazil. Due to their living habits, they are the subject of many medical, veterinary, sanitary, and entomological studies. However, Sarcophagidae species are still poorly studied in forensic entomology, although they are frequently reported in carcasses and even human corpses. Thus, this study aims to identify and compare the developmental stages and intrapuparial morphological characteristics of Peckia (Euboettcheria) collusor to serve as an auxiliary tool in forensic entomology. The pupae collected after zero hour at 27 °C and 32 °C were sacrificed every three hours until the first 24 h and then every six hours until the emergence of the first adults, using 30 pupae each time, totaling 1560 for 27 °C and 1290 for 32 °C. The intrapuparial development time of this fly species under laboratory-controlled conditions was 288 h at 27 °C and 228 h at 32 °C. The 2820 pupae were analyzed according to temperature and classified into eight possible stages. This contributed to the selection of 16 key morphological characteristics to identify the age of the pupae. The identified intrapupal morphological characteristics have great potential to help researchers, experts, technical assistants, and forensic entomologists estimate the minimum post-mortem interval (minPMI) of cadavers.

Microscopic fungi on the corpse - Promising tool requiring further research.

Forensic microbiology is a relatively new area of forensic sciences. It considers the potential of microorganisms to be used in criminal investigations. As most studies involve the role of bacteria in fields like post-mortem interval estimation, personal identification or geolocation, the data on the role of fungi is comparatively scarce. Forensic mycology involves the application of fungi and their structures in forensic cases. The aim of this review is the evaluation of the current state of knowledge on fungi associated with human cadavers and their possible role in estimating the time since death. In accordance with the available reports, we focused on the relation between microscopic fungi isolated from human corpses and the cadaver condition e.g., the stage of decomposition. We also emphasised the contrast between the reported methodologies and attempted to standardise research methods in forensic mycology from sample collection to its storage, mycological analysis and identification of the obtained fungal cultures. Moreover, the potential usage of microscopic fungi in criminal cases was discussed based on various case reports.

Loperamide positive deaths in Sweden 2012-2022 and Finland 2017-2022: Fatal loperamide intoxication exclusively for Sweden.

Loperamide, a potent µ-opioid receptor agonist used as an antidiarrheal drug, exhibits increased bioavailability at supratherapeutic doses, causing potential central nervous system effects. Its misuse for opioid withdrawal relief and euphoria can lead to dangerously elevated blood levels, causing severe cardiac dysrhythmias and death. This study aimed to compare loperamide positive autopsy cases in Sweden and Finland after the introduction of postmortem toxicological analysis of loperamide, focusing on loperamide's role in fatalities and identifying common characteristics among those affected. All cases with detected loperamide in femoral blood at forensic autopsies in Sweden (2012-2022) and Finland (2017-2022) were included. In Sweden, loperamide was detected in 126 individuals, and in Finland, in 111 individuals. The incidence of individuals positive for loperamide in postmortem femoral blood increased steadily over the study duration in both Sweden and Finland. Loperamide related fatalities were observed exclusively in Sweden (n=80), predominantly involving younger males with histories of substance abuse, typically classified as accidental deaths. The group of loperamide nonrelated deaths in Sweden mirrored the entirety of cases in Finland. The concentration of loperamide in postmortem femoral blood was significantly higher in cases where loperamide was considered the cause of death (median 0.140 µg/g) compared to cases where loperamide contributed (median 0.080 µg/g), as well as in deaths unrelated to loperamide in both countries (Sweden: median 0.029 µg/g; Finland: median 0.010 µg/ml). The high limit of quantification for loperamide in Sweden may underestimate therapeutic users in epidemiological assessments. This study underscores the absence of loperamide misuse in Finland and indicates a rising trend of loperamide abuse in Sweden.

Severe colic in a newborn dairy calf caused by a large colostrum curd: a case report.

A newborn female, Holstein calf weighing approximately 38.5 kg developed severe, persistent colic caused by a large colostrum curd located within the calf's abomasum. Based upon 10% body weight, the calf had been fed 4 liters (L) of first-milking colostrum approximately 30 min after birth and an additional 2 L of first-milking colostrum 6 h after the first feeding. Both the first and second feedings used an esophageal tube feeder to deliver the colostrum. Colic developed shortly after the second colostrum feeding. The affected calf did not respond to on-farm supportive medical therapy and was humanely euthanized by a penetrating captive bolt approximately 22 h after the onset of colic. This on-farm colostrum feeding protocol is routinely observed in the current dairy industry. This case demonstrates calves that are fed large volumes of colostrum during a relatively short window of time may develop a large, firm colostrum curd within the abomasum that causes abdominal distension, colic, and occasional death. There is an urgent need for prospective analytical studies that determine the optimal immunoglobulin mass (g/L) and the ideal volume of colostrum fed to newborn calves for both the first and second colostrum feedings within the most beneficial time frame. Guidelines should be developed that minimize complications that adversely affect calf health and well-being while ensuring the successful transfer of passive immunity.

Clinicopathological analysis of NEK1 variants in amyotrophic lateral sclerosis.

Many genes have been linked to amyotrophic lateral sclerosis (ALS), including never in mitosis A (NIMA)-related kinase 1 (NEK1), a serine/threonine kinase that plays a key role in several cellular functions, such as DNA damage response and cell cycle regulation. Whole-exome sequencing studies have shown that NEK1 mutations are associated with an increased risk for ALS, where a significant enrichment of NEK1 loss-of-function (LOF) variants were found in individuals with ALS compared to controls. In particular, the p.Arg261His missense variant was associated with significantly increased disease susceptibility. This case series aims to understand the neuropathological phenotypes resulting from NEK1 mutations in ALS. We examined a cohort of three Scottish patients with a mutation in the NEK1 gene and evaluated the distribution and cellular expression of NEK1, as well as the abundance of phosphorylated TDP-43 (pTDP-43) aggregates, in the motor cortex compared to age- and sex-matched control tissue. We show pathological, cytoplasmic TDP-43 aggregates in all three NEK1-ALS cases. NEK1 protein staining revealed no immunoreactivity in two of the NEK1-ALS cases, indicating a LOF and corresponding to a reduction in NEK1 mRNA as detected by in situ hybridisation. However, the p.Arg261His missense mutation resulted in an increase in NEK1 mRNA molecules and abundant NEK1-positive cytoplasmic aggregates, with the same morphologic appearance, and within the same cells as co-occurring TDP-43 aggregates. Here we show the first neuropathological assessment of a series of ALS cases carrying mutations in the NEK1 gene. Specifically, we show that TDP-43 pathology is present in these cases and that potential NEK1 LOF can either be mediated through loss of NEK1 translation or through aggregation of NEK1 protein as in the case with p.Arg261His mutation, a potential novel pathological feature of NEK1-ALS.

Fentanyl-Related Deaths in Ontario, Canada: Toxicological Findings and Circumstances of Death in 4395 Cases (2020-2022).

Over the last 20 years there has been a significant increase in fentanyl related deaths in Ontario, Canada. This report examines toxicological findings in a series of death investigations in which fentanyl was quantitated to identify the prevalence, trends and demographic data associated with fentanyl in Ontario, Canada, and to highlight the changes in these trends since fentanyl began appearing in casework in Ontario in the early 2000s. A retrospective study of all cases in which fentanyl was quantitated in blood, using liquid chromatography-tandem mass spectrometry, was conducted for the time period between January 1, 2020, and December 31, 2022. A total of 4395 cases were included, 77% of the decedents were male and 23% were female with ages ranging from 0 to 95. The most frequently classified cause of death was mixed drug toxicity (69%) followed by fentanyl intoxication at 19%. Less than 10% of cases where fentanyl was quantitated were classified as non-drug related deaths. Fentanyl concentrations in all cases ranged from 1.3 to > 2000 ng/mL. Other drugs were frequently detected with fentanyl. In mixed drug toxicity cases, stimulants were the most frequently encountered class of drugs: cocaine was identified in 51.8% and methamphetamine was observed in 43.0% of cases, respectively. Detailed reports for select cases were included to provide additional insight into the different case types and to show the difficulty in interpreting blood concentrations without additional detailed case histories. This study provides valuable information for the scientific and medical community regarding the continued use of fentanyl and how patterns of fentanyl use have evolved since it began to appear in forensic casework.

Minimally invasive autopsy - endoscopic approach to post-mortem diagnostics.

The noticeable decline in the number of autopsies performed in recent years requires investigation into the causes of the phenomenon and attempts to prevent it. One potential cause of this trend is fear of disfiguring the body. Carrying out autopsies using a minimally invasive method may reduce the decrease in the number of autopsies performed. The first work on the development of the method and its continuation gave promising results. This allows us to start a discussion on attempts to introduce the method. The solution seems especially justified when the alternative is to completely abandon post-mortem examinations using the traditional method. Laparoscopy and thoracoscopy are tools that allow for accurate imaging and analysis of organ changes. Enriching them with additional tests using endoscopic techniques may have a positive impact on the accuracy of autopsy diagnoses. The development of a clear protocol for minimally invasive post-mortem diagnosis requires further research to determine the accuracy of the method.

Beyond the surface: how ex-vivo diffusion-weighted imaging reveals large animal brain microstructure and connectivity.

Diffusion-weighted Imaging (DWI) is an effective and state-of-the-art neuroimaging method that non-invasively reveals the microstructure and connectivity of tissues. Recently, novel applications of the DWI technique in studying large brains through ex-vivo imaging enabled researchers to gain insights into the complex neural architecture in different species such as those of Perissodactyla (e.g., horses and rhinos), Artiodactyla (e.g., bovids, swines, and cetaceans), and Carnivora (e.g., felids, canids, and pinnipeds). Classical in-vivo tract-tracing methods are usually considered unsuitable for ethical and practical reasons, in large animals or protected species. Ex-vivo DWI-based tractography offers the chance to examine the microstructure and connectivity of formalin-fixed tissues with scan times and precision that is not feasible in-vivo. This paper explores DWI's application to ex-vivo brains of large animals, highlighting the unique insights it offers into the structure of sometimes phylogenetically different neural networks, the connectivity of white matter tracts, and comparative evolutionary adaptations. Here, we also summarize the challenges, concerns, and perspectives of ex-vivo DWI that will shape the future of the field in large brains.

Does a postmortem redistribution affect the concentrations of the 7 azaindole-derived synthetic cannabinoid 5F-MDMB-P7AICA in tissues and body fluids following pulmonary administration to pigs?

Many fatal intoxications have been reported in connection with the consumption of newer, highly potent synthetic cannabinoids. Yet, a possible postmortem redistribution (PMR) might complicate reliable interpretation of analytical results. Thus, it is necessary to investigate the PMR-potential of new synthetic cannabinoids. The pig model has already proven to be suitable for this purpose. Hence, the aim of this study was to study the PMR of the synthetic cannabinoid 5F-MDMB-P7AICA and its main metabolite 5F-MDMB-P7AICA-dimethylbutanoic acid (DBA). 5F-MDMB-P7AICA (200 µg/kg body weight) was administered by inhalation to anesthetized and ventilated pigs. At the end of the experiment, the animals were euthanized and stored at room temperature for 3 days. Tissue and body fluid samples were taken daily. Specimens were analyzed after solid phase extraction using a standard addition method and LC-MS/MS, blood was quantified after protein precipitation using a validated method. In perimortem samples, 5F-MDMB-P7AICA was found mainly in adipose tissue, bile fluid, and duodenum contents. Small amounts of 5F-MDMB-P7AICA were found in blood, muscle, brain, liver, and lung. High concentrations of DBA were found primarily in bile fluid, duodenum contents, urine, and kidney/perirenal fat tissue. In the remaining tissues, rather low amounts could be found. In comparison to older synthetic cannabinoids, PMR of 5F-MDMB-P7AICA was less pronounced. Concentrations in blood also appear to remain relatively stable at a low level postmortem. Muscle, kidney, fat, and duodenum content are suitable alternative matrices for the detection of 5F-MDMB-P7AICA and DBA, if blood specimens are not available. In conclusion, concentrations of 5F-MDMB-P7AICA and its main metabolite DBA are not relevantly affected by PMR.

Implications of intracochlear decomposition gas formation in non-putrefied cadavers.

Introduction: Postmortem computed tomography (pmCT) prior to forensic autopsy has become increasingly important in recent decades, especially in forensic documentation of single injuries, injury patterns, and causes of death. Postmortem decomposition gas formation can also be detected in pmCT scans, which might affect cochlear implant research in postmortem human temporal bones (TBs). Material and methods: Fifty non-putrefied hanging fatalities within a 2-year period (January 2017 to December 2019) were included with 100 TBs. Each body underwent whole-body pmCT prior to forensic autopsy. PmCT scans were analyzed with respect to the presence of intracochlear gas despite the lack of putrefaction at autopsy by an experienced fellow neurotologist. Results: PmCT revealed gas formation in two individuals despite the lack of head trauma and putrefaction at postmortem examination and autopsy. Both individuals showed enclosed gas in the vestibule and the cochlea on both sides. Discussion: Intracochlear gas formation, most likely related to decomposition, may occur despite the lack of putrefaction at postmortem examination and autopsy and can be detected by pmCT. This finding seems to be rather rare in non-traumatic death cases but might affect cochlear pressure research in postmortem human TB.

Selective postmortem arterial angiography of head and neck using digital x-ray or computed tomography: A practical and rapid method to identify vascular injuries.

Identification of vascular injuries is crucial for complete postmortem evaluation and understanding of trauma deaths by the Medical Examiner. Some vascular injuries are difficult to evaluate due to challenging anatomic locations, especially in the head and neck. Documenting injuries of the facial and vertebral arteries is challenging and necessitates time-consuming dissections that can create artifacts and disfigurement. In busy medical examiner offices with a significant number of traumatic injuries, finding a creative solution to employ reliable postmortem angiography is desirable. At the Office of the Chief Medical Examiner for the State of Maryland (OCME), we created and effectively implemented a selective angiography procedure using traditional indwelling Foley catheters and water-soluble barium swallow contrast to evaluate arterial injuries using either digital radiography or computed tomography imaging modalities. This technique and imaging interpretation can be performed by a medical examiner or forensic pathology fellow after basic technical training and basic radiology training. This study outlines the technique, methods, and utilization of the procedure and describes the findings of six deaths due to vascular lesions from different injury mechanisms and disease processes and describes the ease of implementation on a broader scale in busy Medical Examiner's offices.

Effect of cytochrome c release on the mitochondrial-dependent apoptosis and quality deterioration of black rockfish (Sebastes schlegelii) postmortem storage.

Apoptosis was associated with decreased sensory quality attributes of fish during postmortem storage. Based on cytochrome c (cyt-c) release plays a crucial role in apoptosis, the study aims to investigate the factors regulating cyt-c release and whether cyt-c acts as an endogenous pro-oxidant to trigger lipid oxidation. Within 12 h postmortem, dramatic changes in the intramuscular environment (glycogen from 1.57 mg/g to 0.65 mg/g; ATP reduced by 92.91%; pH value reaching the lowest (pH = 7.14)) and the mitochondrial environment (accumulation of mitochondrial ROS and Ca2+ levels) are induced mitochondrial swelling and opening of the MPTP (increased 34.35% and 31.91%), leading to the release of cyt-c from the mitochondria into the cytoplasm and the activation of caspase-3. This leads to lipid oxidation and degradation of myofibrillar proteins, accelerating quality deterioration in color and texture. The results suggest that cyt-c is involved in lipid oxidation during postmortem through the apoptotic mitochondrial pathway.

Morphometric Indicators of Liver Acini of Deceased Newborns Depending on the Time of Death.

We studied morphometric changes in the liver acini of dead newborns depending on the duration of the postmortem period. Autopsy samples of the liver tissue from 49 dead newborns were divided into 7 groups depending on the time of death. Liver tissue samples were taken from the upper and lower areas of the liver in the supine position of newborns; paraffin sections were prepared and stained with hematoxylin and eosin. The morphometric analysis of histological preparations revealed a progressive decrease in the mean size of the liver plates (trabeculae) and, conversely, an increase in the area of sinusoids with increasing the duration of the postmortem period; these changes were due to the postmortem redistribution of the blood and autolysis processes. More significant changes were noted in acinar zone 3 of the lower part of the liver. The revealed intra-acinar features of postmortem changes should be taken into account for their differential diagnosis with pathological processes that developed during life, in particular, the signs of congestion and peliosis of the liver.

Sudden Death: A Practical Autopsy Approach to Unexplained Mediastinitis Due to Fatal Untreated Neck Infections-A Systematic Review.

Neck infections are often prone to being underestimated and can manifest insidiously. The spread of infection can lead to translocation into thoracic areas, causing descending necrotizing mediastinitis (DNM). However, the application of the post-mortem approach in such cases is not well-described in the literature. A literature review was carried out according to the PRISMA methods. Nine papers were included in the final review, revealing different levels of involvement of neck layers that can be linked to different causes. Expertise with respect to the anatomy of the fasciae and spaces of the neck enables an understanding of the pathogenesis of DNM. However, a clear autoptic description was not provided in any of the articles. Therefore, we also employed a practical post-mortem approach to cases of death due to DNM. It is fundamental for pathologists to identify the exact head and neck structures involved. Providing dissectors with support from an otolaryngologist could be useful. This paper could help address such difficult cases.

Assessment of urine drug screen utility at autopsy to predict laboratory postmortem blood toxicology.

When faced with increasing drug-related deaths and decline in practicing forensic pathologists, the need to quickly identify toxicology-related deaths is evident in order to appropriately triage cases and expedite turnaround times. Lateral flow immunoassays conducted pre-autopsy offer quick urine drug screen (UDS) results in minutes and are used to inform the need for autopsy. Over 1000 medicolegal cases were reviewed to compare UDS results to laboratory enzyme-linked immunosorbent assay (ELISA) blood results to evaluate how well autopsy UDS predicted laboratory findings. Mass spectral analysis was performed on ELISA-positive specimens and these data were used to investigate UDS false-negative (FN) results when possible. Five different UDS devices (STAT One Step Drug of Abuse dip card and cassette, Premiere Biotech multi-drug and fentanyl dip cards and ATTEST 6-acetylmorphine (6-AM) dip card) were tested encompassing 11 drug classes: 6-AM, amphetamine/methamphetamine, benzodiazepines, benzoylecgonine, fentanyl, methadone, opioids, phencyclidine, and delta-9-tetrahydrocannabinol. Sensitivity, specificity, efficiency, and positive and negative predictive values >80% indicated that UDS was useful for predicting cases involving benzoylecgonine, methadone, methamphetamine, and phencyclidine. UDS was unreliable in predicting amphetamine, benzodiazepines, fentanyl, and opiates-related cases due to a high percentage of FN (up to 11.2%, 8.0%, 12.4%, and 5.5%, respectively) when compared to ELISA blood results. For the later analytes, sensitivities were as low as 57.5%, 60.0%, 72.2%, and 66.7%, respectively. Overall results support that UDS cannot replace laboratory testing. Because UDS is subject to false-positive and FN results users must understand the limitations of using UDS for triage or decision-making purposes.

[Legal and forensic medical problems of postmortem donation]. / Pravovye i sudebno-meditsinskie problemy posmertnogo donorstva.

The article is devoted to legal and forensic medical problems of postmortem donation. The substantive provisions of postmortem donation, as well as normative legal documents regulating the processes of organs harvesting from deceased persons for subsequent transplantation and governing the work of transplantologists and forensic medical experts have been considered. The practical examples illustrating the essence and nature of the problem of postmortem forensic medical expertise of persons with absent organs has been given and the importance of the participation of a forensic medical expert involved in the decision-making process on possibility (or impossibility) of the corpse's organs and tissues explantation without prejudice to the further expert examination has been emphasized. The authors pay particular attention to the inadequacy of the legal framework, including the lack of a clear understanding of the legal status of the person holding the position of forensic medical expert, who provides an expert opinion on the organs' explantation.

Post-mortem analysis of dolutegravir, tenofovir, lamivudine and efavirenz penetration in multiple CNS compartments.

BACKGROUND: Central nervous system (CNS) compartmentalization provides opportunity for HIV persistence and resistance development. Differences between cerebrospinal fluid (CSF) and cerebral matter regarding HIV persistence are well described. However, CSF is often used as surrogate for CNS drug exposure, and knowledge from solid brain tissue is rare. METHODS: Dolutegravir, tenofovir, lamivudine and efavirenz concentrations were measured across 13 CNS regions plus plasma in samples collected during autopsy in 49 Ugandan decedents. Median time from death to autopsy was 8 (IQR 5,15) hours. To evaluate postmortem redistribution, a time course study was performed in a mouse model. RESULTS: Regions with the highest penetration ratios were choroid plexus/arachnoid (dolutegravir and tenofovir), CSF (lamivudine), and cervical spinal cord/meninges (efavirenz); the lowest were corpus callosum (dolutegravir and tenofovir), frontal lobe (lamivudine), and parietal lobe (efavirenz). On average, brain concentrations were 84%, 87%, and 76% of CSF for dolutegravir, tenofovir, and lamivudine respectively. Postmortem redistribution was observed in the mouse model, with tenofovir and lamivudine concentration increased by 350% and efavirenz concentration decreased by 24% at 24-hours post-mortem. CONCLUSION: Analysis of postmortem tissue provides a unique opportunity to investigate CNS antiretroviral penetration. Regional differences were observed paving the way to identify mechanisms of viral compartmentalization and/or neurotoxicity.

Difficulties associated with the interpretation of post-mortem toxicology.

While post-mortem (PM) toxicology results provide valuable information towards ascertaining both the cause and manner of death in coronial cases, there are also significant difficulties associated with the interpretation of PM drug levels. Such difficulties are influenced by several pharmacokinetic and pharmacodynamic factors including PM redistribution, diffusion, site-to-site variability in drug levels, different drug properties and metabolism, bacterial activity, genetic polymorphisms, tolerance, resuscitation efforts, underlying conditions and the toxicity profile of cases (i.e. single- or mixed-drug toxicity). A large body of research has been dedicated to better understanding and even quantifying the influence of these factors on PM drug levels. For example, several investigative matrices have been developed as potential indicators of PM redistribution, but they have limited practical value. Reference tables of clinically relevant therapeutic, toxic and potentially fatal drug concentrations have also been compiled, but these unfortunately do not provide reliable reference values for PM toxicology. More recent research has focussed on developing databases of peripheral PM drug levels for a variety of case-types to increase transferability to real-life cases and improve interpretations. Changes to drug levels after death are inevitable and unavoidable. As such, guidelines and practices will continue to evolve as we further our understanding of such phenomena.

Coenzyme Q deficiency may predispose to sudden unexplained death via an increased risk of cardiac arrhythmia.

Cardiac arrhythmia is currently considered to be the direct cause of death in a majority of sudden unexplained death (SUD) cases, yet the genetic predisposition and corresponding endophenotypes contributing to SUD remain incompletely understood. In this study, we aimed to investigate the involvement of Coenzyme Q (CoQ) deficiency in SUD. First, we re-analyzed the exome sequencing data of 45 SUD and 151 sudden infant death syndrome (SIDS) cases from our previous studies, focusing on previously overlooked genetic variants in 44 human CoQ deficiency-related genes. A considerable proportion of the SUD (38%) and SIDS (37%) cases were found to harbor rare variants with likely functional effects. Subsequent burden testing, including all rare exonic and untranslated region variants identified in our case cohorts, further confirmed the existence of significant genetic burden. Based on the genetic findings, the influence of CoQ deficiency on electrophysiological and morphological properties was further examined in a mouse model. A significantly prolonged PR interval and an increased occurrence of atrioventricular block were observed in the 4-nitrobenzoate induced CoQ deficiency mouse group, suggesting that CoQ deficiency may predispose individuals to sudden death through an increased risk of cardiac arrhythmia. Overall, our findings suggest that CoQ deficiency-related genes should also be considered in the molecular autopsy of SUD.

Postmortem Diffusion of Aconitum Alkaloids and Their Metabolites in Rabbits.

OBJECTIVES: To explore the postmortem diffusion rule of Aconitum alkaloids and their metabolites in poisoned rabbits, and to provide a reference for identifying the antemortem poisoning or postmortem poisoning of Aconitum alkaloids. METHODS: Twenty-four rabbits were sacrificed by tracheal clamps. After 1 hour, the rabbits were administered with aconitine LD50 in decocting aconite root powder by intragastric administration. Then, they were placed supine and stored at 25 ℃. The biological samples from 3 randomly selected rabbits were collected including heart blood, peripheral blood, urine, heart, liver, spleen, lung and kidney tissues at 0 h, 4 h, 8 h, 12 h, 24 h, 48 h, 72 h and 96 h after intragastric administration, respectively. Aconitum alkaloids and their metabolites in the biological samples were analyzed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). RESULTS: At 4 h after intragastric administration, Aconitum alkaloids and their metabolites could be detected in heart blood, peripheral blood and major organs, and the contents of them changed dynamically with the preservation time. The contents of Aconitum alkaloids and their metabolites were higher in the spleen, liver and lung, especially in the spleen which was closer to the stomach. The average mass fraction of benzoylmesaconine metabolized in rabbit spleen was the highest at 48 h after intragastric administration. In contrast, the contents of Aconitum alkaloids and their metabolites in kidney were all lower. Aconitum alkaloids and their metabolites were not detected in urine. CONCLUSIONS: Aconitum alkaloids and their metabolites have postmortem diffusion in poisoned rabbits, diffusing from high-content organs (stomach) to other major organs and tissues as well as the heart blood. The main mechanism is the dispersion along the concentration gradient, while urine is not affected by postmortem diffusion, which can be used as the basis for the identification of antemortem and postmortem Aconitum alkaloids poisoning.