Divergent landscapes of A-to-I editing in postmortem and living human brain.

Adenosine-to-inosine (A-to-I) editing is a prevalent post-transcriptional RNA modification within the brain. Yet, most research has relied on postmortem samples, assuming it is an accurate representation of RNA biology in the living brain. We challenge this assumption by comparing A-to-I editing between postmortem and living prefrontal cortical tissues. Major differences were found, with over 70,000 A-to-I sites showing higher editing levels in postmortem tissues. Increased A-to-I editing in postmortem tissues is linked to higher ADAR and ADARB1 expression, is more pronounced in non-neuronal cells, and indicative of postmortem activation of inflammation and hypoxia. Higher A-to-I editing in living tissues marks sites that are evolutionarily preserved, synaptic, developmentally timed, and disrupted in neurological conditions. Common genetic variants were also found to differentially affect A-to-I editing levels in living versus postmortem tissues. Collectively, these discoveries offer more nuanced and accurate insights into the regulatory mechanisms of RNA editing in the human brain.

Identification of skin bacterial profiles of early deceased bodies and the relation to post-mortem interval.

Post-mortem microbiology (PMM) is an important tool in identifying possible causes of sudden unexpected death, as an infectious cause is highly suspected. However, contamination is a major problem in microbiology, and this has increased the difficulty determining the true pathogen that contributes to death in post-mortem cases. Skin commensals are common contaminants in blood cultures. This study was conducted to investigate the skin flora on early deceased bodies and observe the bacteria detected at different post-mortem intervals (PMIs). As blood is usually drawn from the neck and femoral sites for PMM examination, the two body sites were chosen as the sampling sites. Skin swab samples from the neck and femoral (n=80) of each early deceased body were collected by sterile cotton swabs. DNA was extracted from the swabs and then subjected to high-throughput 16S rRNA sequencing by using the Illumina MiSeq platform. Staphylococcus was found to be the most dominant genus in both neck and femoral sites. LEfSe results showed that Cutibacterium is significantly different at the neck site while Corynebacterium is more abundant at femoral site. There are significant differences at genus level between PMI<5H and PMI>5H at both neck and femoral sites. The findings of the present study may act as a reference for microbiologists and forensic pathologists when mixed growth or contamination occurs in post-mortem blood cultures.

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.

Effect of humidity on postmortem changes in rats.

IMPORTANCE: In veterinary forensic science, accurately determining the postmortem interval (PMI) is crucial for identifying the causes of animal deaths. Autolysis, a significant postmortem process, influences PMI estimation, but its relationship with humidity is not well understood. OBJECTIVE: This study aimed to improve the accuracy of PMI estimates in veterinary forensic cases by looking into how different humidity levels affect autolysis in different organs of rats. METHODS: The study involved 38 male rats, examining histopathological changes in their heart, liver, and pancreas. These organs were subjected to controlled humidity levels (20%, 55%, and 80%) at a constant 22°C. Tissue samples were collected at several intervals (0 h, 12 h, 24 h, 3 days, and 8 days) for comprehensive analysis. RESULTS: Distinct autolytic characteristics in animal organs emerged under varying humidity conditions. The low-humidity environment rapidly activated autolysis more than the high-humidity environment. In addition, it was found that lower humidity caused nuclear pyknosis, cytoplasmic disintegration, and myofiber interruption. The liver, in particular, showed portal triad aggregation and hepatocyte individuation. The pancreas experienced cell fragmentation and an enlarged intracellular space. High humidity also caused the loss of striations in cardiac tissues, and the liver showed vacuolation. Under these conditions, the pancreas changed eosinophilic secretory granules. CONCLUSIONS AND RELEVANCE: The study successfully established a clear connection between the autolytic process in PMIs and relative humidity. These findings are significant for developing a more accurate and predictable method for PMI estimation in the field of veterinary forensic science.

Identification of post-mortem product of zolpidem degradation by hemoglobin via the Fenton reaction.

Zolpidem, N,N-dimethyl-2-[6-methyl-2-(4-methylphenyl)imidazo[1,2-a]pyridin-3-yl]acetamide, is a hypnotic agent widely used in clinical practice but is detected in many clinical cases of fatal intoxication and suicide. In forensic toxicology, the precise determination of zolpidem concentration in blood is a must to provide concrete evidence of death by zolpidem poisoning. However, the concentrations of zolpidem in blood at autopsy often differ from those at the estimated time of death. In the present study, we found that zolpidem was degraded by hemoglobin (Hb) via the Fenton reaction at various temperatures. The mechanism underlying zolpidem degradation involved the oxidation of its linker moiety. The MS and MS/MS spectra obtained by liquid chromatography quadrupole-Orbitrap mass spectrometry (LC-Q-Orbitrap-MS) showed the formation of 2-hydroxy-N,N-dimethyl-2-(6-methyl-2-(p-tolyl)imidazo[1,2-a]pyridin-3-yl)acetamide (2-OH ZOL) in Hb/H2O2 solution incubated with zolpidem and in the blood of several individuals who died from ingestion of zolpidem. These results suggest that 2-OH ZOL is the post-mortem product of zolpidem degradation by Hb via the Fenton reaction.

Evaluating the impact of hot water killing larvae on gene expression using the transformer gene in Cochliomyia macellaria (Diptera: Calliphoridae).

In forensic entomology, determining the age of a larva from a body to estimate time since death is commonly performed through the measurement of a physical trait. Gene expression has been studied as an alternative age estimation approach, but the storage conditions required for these studies are different than those used in forensic entomological casework. Studies analyzing gene expression prioritize the preservation of RNA, which requires fresh tissue and ultra-cold storage. Casework, in contrast, utilizes hot water killing specimens that may not be analyzed for a long period after collection. In the current study, the impact of hot water killing on gene expression was assessed for larval samples of the forensically important blow fly, Cochliomyia macellaria. Successful amplification of the sex-determining gene, transformer, was tested across larvae ranging in size from 3.22 to 16.85 mm in length after storage times of 1-2 weeks, 4-5 weeks, and 8-9 weeks at 4°C in RNAlater. Larvae hot water killed were processed in tandem with larvae stored live to allow for a direct assessment of the impact of boiling on gene expression. As expected, the transformer gene was successfully amplified in all larvae stored live. For the hot water-killed larvae, the success rate was only slightly lower, with 3 out of 75 larvae not generating a sex-specific band pattern. The results show gene expression can be used for hot water-killed samples, though future work across different genes, species, and extending to quantitative gene expression methods is needed.

Effect of ultrasound-assisted L-lysine treatment on pork meat quality and myofibrillar protein properties during postmortem aging.

This paper aimed to investigate the effects of ultrasound-assisted L-lysine treatment on meat quality and myofibrillar proteins (MPs) properties of pork longissimus dorsi during postmortem aging. The results revealed that the L-lysine (Lys) and/or ultrasound treatment significantly increased (p < 0.05) the water-holding capacity and tenderness of the pork during postmortem aging, while the ultrasound-assisted Lys treatment had the lowest cooking loss, pressurization loss, Warner-Bratzler shear force, and hardness. In addition, L-lysine and/or ultrasound treatment increased (p < 0.05) pH value, T21, and myofibrillar fragmentation index, while the ultrasound-assisted Lys treatment had the highest value. Meanwhile, the protein solubility was increased with Lys and/or ultrasound treatment during postmortem aging, and ultrasound-assisted Lys treatment had the highest solubility, reaching 88.19%, 92.98%, and 91.73% at 0, 1, and 3 days, respectively. The result of protein conformational characteristics showed that Lys and/or ultrasound treatment caused the unfolding of the α-helix structure, resulting in the exposure of more hydrophobic amino acids and buried sulfhydryl groups, ultimately enhancing MPs solubility. In summary, ultrasound-assisted Lys treatment altered the structure of MPs, resulting in the enhancement of the water-holding capacity and tenderness of the pork. PRACTICAL APPLICATION: This study showed that ultrasound-assisted L-lysine (Lys) treatment could enhance the water-holding capacity and tenderness of pork during postmortem aging. The results might provide a reference for the application of ultrasound-assisted Lys treatment on the improvement of pork meat quality. To facilitate practical applications in production, the development of medium and large-sized ultrasound equipment for conducting small-scale and pilot experiments is crucial for future research.

Volatile organic compounds produced during postmortem processes can be linked via chromatographic profiles to individual postmortem bacterial species.

Decomposition odor is produced during postmortem mammalian tissue breakdown by bacteria, insects, and intrinsic chemical processes. Past research has not thoroughly investigated which volatile organic compounds (VOCs) can be linked directly to individual bacterial species on decomposing remains. The purpose of this study was to profile the VOCs produced over time by individual species of bacteria using comprehensive two-dimensional gas chromatography (GC×GC) to expand our foundational knowledge of what each bacterial species contributes to decomposition odor. Five different species of bacteria (Bacillus subtilis, Ignatzschineria indica, Ignatzschineria ureiclastica, Curtobacterium luteum, and Vagococcus lutrae) were cultured on standard nutrient agar individually and monitored daily using solid phase microextraction arrow (SPME Arrow) and GC×GC in combination with quadrupole mass spectrometry (qMS) and flame ionization detection (FID). The GC×GC-qMS/FID approach was used to generate rich VOC profiles that represented the bacterial species' metabolic VOC production longitudinally. The data obtained from the chromatographic output was used to compare with a prior study using one-dimensional GC-qMS, and also between each of the five species to investigate the extent of overlap between species. No single VOC could be found in all five bacterial species investigated, and there was little overlap in the profile between species. To further visualize these differences, chromatographic peak data was investigated using two different ordination strategies, principal component analysis (PCA) and principal coordinate analysis (PCoA). The two ordination strategies were compared with each other using a Procrustes analysis. This was performed to understand differences in ordination strategies between the separation science community and chemical ecological community. Overall, ordination strategies were found to produce similar results, as evidenced by the correlation of PCA and PCoA in the Procrustes analysis. All analysis strategies yielded distinct VOC profiles for each species. Further study of additional species will support understanding of the holistic view of decomposition odor from a chemical ecology perspective, and further support our understanding of the production of decomposition odor that culminates from such a complex environment.

Gray-white matter contrast reversal on T1-weighted spin-echo in postmortem brain.

PURPOSE: The image contrast of postmortem magnetic resonance imaging (MRI) may differ from that of antemortem MRI because of circulator arrest, changes in postmortem tissue, and low-body-temperature scanning conditions. In fact, we have found that the signal intensity of white matter (WM) on T1-weighted spin-echo (T1WSE) images of the postmortem brain was lower than that of gray matter (GM), which resulted in image contrast reversal between GM and WM relative to the living brain. However, the reason for this phenomenon is unclear. Therefore, the aim of this study is to clarify the reason why image contrast reversal occurs between GM and WM of the postmortem brain. MATERIALS AND METHODS: Twenty-three corpses were included in the study (mean age, 60.6 years; range: 19-60 years; mean rectal temperature at scan, 6.9℃; range: 4-11℃). On a 1.5 T MRI system, postmortem T1W-SE MRI of the brain was conducted in the 23 corpses prior to medico-legal autopsy. Next, T1 and T2 of the GM and WM at the level of the basal ganglia were determined in the same participants using inversion recovery and multiple SE sequences, respectively. The proton density (PD) was also calculated from the T1 and T2 images (in the same slice). RESULTS: T1W-SE image contrast between the GM and WM of all postmortem brains was inverted relative to the living brain. T1 (579 ms in GM and 307 ms in WM) and PD (64 in GM and 44 in WM) of the postmortem brain decreased compared with the living brain. While T1 of WM/GM remained below 1 even postmortem, the PD of WM/GM decreased. T2 (110 ms in GM and 98 ms in WM) of the postmortem brain did not differ from the living brain. CONCLUSION: The decrease in PD of WM/GM in the postmortem brain may be the major driver of contrast reversal between the GM and WM relative to the living brain.

Postmortem mitochondria function in longissimus lumborum of Angus and Brahman steers.

Mitochondria function and integrity may impact postmortem metabolism and meat quality development. Adaptations in heat tolerant Brahman may persist to limit cellular stress postmortem. Our objective was to evaluate glycolysis, pH decline, and mitochondria function in longissimus lumborum (LL) from Angus and Brahman steers (N = 28) early postmortem (1 to 6 h) and after rigor (24 h). We evaluated metabolites of anaerobic glycolysis, ATP, pH, and temperature, and determined mitochondria oxygen consumption rate (OCR) in permeabilized fibers. The main effects of breed (b) and time (t) and the interaction were tested. Brahman LL contained greater ATP during the first 6 h postmortem; Brahman also tended to exhibit a slower pH decline (b × t, P = 0.07) and more rapid temperature decline (b × t, P < 0.001), but metabolites of anaerobic glycolysis were not different. Mitochondria in Brahman and Angus LL were well-coupled and respired at 1 h postmortem. However, outer membrane integrity became increasingly compromised postmortem (t, P < 0.001). Brahman tended to exhibit greater electron transport system capacity (b, P < 0.1) and had greater capacity for oxidative phosphorylation (complex I and II substrates) at 6 h compared with Angus (P < 0.001). In totality, greater ATP, slower pH decline, and enhanced mitochondria capacity indicate that Brahman possess mitochondrial properties or cellular adaptations that help protect the cell during energy stress postmortem. Slower pH and more rapid temperature decline in LL from Brahman may also help preserve mitochondria function postmortem.

LC-MS-based metabolomics reveals metabolite dynamic changes of beef after superchilling early post-mortem.

To explore the underlying mechanisms by which superchilling (SC, -3 °C within 5 h of slaughter) improves beef tenderness, an untargeted metabolomics strategy was employed. M. Longissimus lumborum (LL) muscles from twelve beef carcasses were assigned to either SC or very fast chilling (VFC, 0 °C within 5 h of slaughter) treatments, with conventional chilling (CC, 0 âˆ¼ 4 °C until 24 h post-mortem) serving as the control (6 per group). Biochemical properties and metabolites were investigated during the early post-mortem period. The results showed that the degradation of µ-calpain and caspase 3 occurred earlier in SC treated sample, which might be attributed to the accelerated accumulation of free Ca2+. The metabolomic profiles of samples from the SC and CC treatments were clearly distinguished based on partial least squares-discriminant analysis (PLS-DA) at each time point. It is noteworthy that more IMP and 4-hydroxyproline were found in the comparison between SC and CC treatments. According to the results of metabolic pathways analysis and the correlation analysis between traits related to tenderness and metabolites with significant differences (SC vs. CC), it can be suggested that the tenderization effect of the SC treatment may be related to the alteration of arginine and proline metabolism, and purine metabolism in the early post-mortem phase.

Postmortem metabolomics: influence of time since death on the level of endogenous compounds in human femoral blood. Necessary to be considered in metabolome study planning?

INTRODUCTION: The (un)targeted analysis of endogenous compounds has gained interest in the field of forensic postmortem investigations. The blood metabolome is influenced by many factors, and postmortem specimens are considered particularly challenging due to unpredictable decomposition processes. OBJECTIVES: This study aimed to systematically investigate the influence of the time since death on endogenous compounds and its relevance in designing postmortem metabolome studies. METHODS: Femoral blood samples of 427 authentic postmortem cases, were collected at two time points after death (854 samples in total; t1: admission to the institute, 1.3-290 h; t2: autopsy, 11-478 h; median ∆t = 71 h). All samples were analyzed using an untargeted metabolome approach, and peak areas were determined for 38 compounds (acylcarnitines, amino acids, phospholipids, and others). Differences between t2 and t1 were assessed by Wilcoxon signed-ranked test (p < 0.05). Moreover, all samples (n = 854) were binned into time groups (6 h, 12 h, or 24 h intervals) and compared by Kruskal-Wallis/Dunn's multiple comparison tests (p < 0.05 each) to investigate the effect of the estimated time since death. RESULTS: Except for serine, threonine, and PC 34:1, all tested analytes revealed statistically significant changes between t1 and t2 (highest median increase 166%). Unpaired analysis of all 854 blood samples in-between groups indicated similar results. Significant differences were typically observed between blood samples collected within the first and later than 48 h after death, respectively. CONCLUSIONS: To improve the consistency of comprehensive data evaluation in postmortem metabolome studies, it seems advisable to only include specimens collected within the first 2 days after death.

Assessing the impact of ultrasound on the rate and extent of early post-mortem glycolysis in bovine Longissimus thoracis et lumborum.

The rate of pH decline, early post-mortem, has been identified as a key factor that impacts the tenderness of meat, and manipulating this rate of pH decline is highly relevant to ensure consistent high quality meat. Ultrasound is a potential intervention in early post - mortem muscle that may have an impact on the rate of glycolysis through its ability to alter enzyme activity. Following a variety of different ultrasound treatments frequencies (25 and 45 kHz) and durations (15, 30 and 45 min), it was found, when analysed in muscle, that ultrasound treatment duration, specifically the 30 min treatment, and interaction between treatment duration and frequency, had a significant impact on the rate of pH decline, post - treatment. Frequency did not have a significant effect on the rate of pH decline, post - treatment, in muscle. Ultrasound did not have a significant permanent effect on the activity of glycolytic enzymes present in bovine Longissimus lumborum et thoracis muscle, where no significant differences were observed on the rate of pH decline and rate of change of reducing sugars, glycogen and lactic acid, when analysed in an in vitro glycolytic buffer. It seems that the impact observed in intact muscle is not as a consequence of a permanent change in enzymatic activity, instead indicating an impact on conditions in the muscle which enhanced enzyme activity.

The influence of rehydration on decomposition in the Highveld region of South Africa-Using a pig model.

Researchers have observed that rainfall may re-initiate decomposition in desiccated tissue; however, no conclusive research-based evidence exists on the specific effects of rehydration on decomposition. Therefore, this study aimed to assess the effects of artificial rehydration on the progression of decomposition following the advanced stage of decomposition. Twelve adult pig cadavers (8 experimental; 4 controls) were placed in the central Highveld of South Africa during cooler (April-July 2021) and warmer (August-November 2021) months. Decomposition was scored approximately biweekly to obtain the total body score, and accumulated degree days (ADD) were calculated for each pig. All pig cadavers were covered by chicken wire cages with transparent tarps to control for natural rehydration and scavenging. Once the experimental pig cadavers reached a three-visit stasis in the advanced phase of decomposition, they were artificially rehydrated, and changes in the progression of decomposition between the control and experimental groups were plotted (ADD against TBS) for observation. The rehydrated experimental pig cadavers showed re-initiation of decay and insect re-colonization, while the control cadavers mainly remained in a state of stasis with insect activity ceased altogether. Greater cadaver decomposition islands and a color change post-rehydration were also noted in some experimental cadavers. This supports the need for future research on the impact of rehydration, including associated soil moisture on decomposition rates, progression, and invertebrate colonization, which will enhance our understanding of the effects these environmental factors have on the accuracy of post-mortem interval estimation.

[Features of detection and interpretation of intravital and postmortem changes according to the results of traditional X-ray and X-ray computed tomography of objects from historical graves and artefacts]. / Osobennosti vyyavleniya i interpretatsii prizhiznennykh i posmertnykh izmenenii po rezul'tatam traditsionnoi rentgenografii i rentgenovskoi komp'yuternoi tomografii ob"ektov iz istoricheskikh zakhoronenii i artefaktov.

OBJECTIVE: To study emergence mechanism, physical nature, pattern of intravital and postmortem changes of biological and non-biological objects originated in the period from 1550 to 1918 yr. using traditional X-ray and X-ray computed tomography. MATERIAL AND METHODS: The relics of Saint Macarius the Roman of Novgorod, the remains of the First Reverend of the Resurrection Novodevichy Convent in Saint Petersburg Mother Superior Theophania, damages on the chair leg on which Tsesarevich Alexey sat during the shooting of Russian Emperor Nicholas II, his family and entourage in 1918 in Yekaterinburg were stidued. RESULTS AND CONCLUSION: The application of highly informative methods of traditional X-ray and X-ray computed tomography of biological and non-biological objects showed their high informativity and allowed to correctly interpret the emergence mechanism, physical nature, pattern of intravital and postmortem changes of skeleton bones and historical artefact (chair legs) originated long ago. The necessity of special professional training and advanced training of experts in forensic radiology to prevent possible diagnostic and expert errors has been substantiated.

Postmortem concentrations for total blood carbon monoxide (TBCO) as a novel biomarker for carbon monoxide (CO) poisonings.

Total blood carbon monoxide (TBCO) showed promising results in improving accuracy of CO determinations in blood and presenting better stability to different storage conditions. Therefore, it was proposed as an alternative biomarker to carboxyhemoglobin (COHb) for CO poisoning diagnosis. However, given that current interpretation reference values exist for COHb only, it is difficult to implement TBCO analysis in routine. Therefore, we aimed at determining TBCO reference values for postmortem CO poisoning cases. A previously validated method for TBCO analysis via gas chromatography-mass spectrometry was applied to cardiac, peripheral, cranial and spleen blood samples collected from 92 autopsies. Autopsy cases included 21 non-CO-related and 71 CO-related cases with varying postmortem intervals (PMIs). Statistical analyses were performed using statistical software R Studio. When comparing lower to higher PMIs for non-CO-related cases, no significant differences were found, which suggests that CO formation or degradation at low PMIs does not occur. Spleen blood showed potential as an alternative matrix to CO determinations in cases with sample availability issues but needs to be evaluated for CO-positive cases. Results for cardiac blood in CO-related autopsies showed a positive correlation between COHb and TBCO values (R = 0.78). This value is lower than what is found in the literature, suggesting that even though COHb and TBCO are correlated, a potential underestimation of the true CO exposure might occur if only COHb values are taken into consideration. Samples were divided into CO exposure groups based on COHb concentrations, and with the data obtained, classification into the following TBCO concentration groups is proposed: no significant CO exposure case <6 µmol/mL, medium CO exposure case 6-20 µmol/mL and high CO exposure case >20 µmol/mL. Even if a higher number of samples in each group would enable to increase the confidence, these results are very promising and highlight the importance of TBCO measurement.

Inhibition of pyruvate dehydrogenase accelerates anaerobic glycolysis under postmortem simulating conditions.

This research aimed to explore the potential influence of mitochondria on the rate of anaerobic glycolysis. We hypothesized that mitochondria could reduce the rate of anaerobic glycolysis and pH decline by metabolizing a portion of glycolytic pyruvate. We utilized an in vitro model and incorporated CPI-613 and Avidin to inhibit pyruvate dehydrogenase (PDH) and pyruvate carboxylase (PC), respectively. Four treatments were tested: 400 µM CPI-613, 1.5 U/ml Avidin, 400 µM CPI-613 + 1.5 U/ml Avidin, or control. Glycolytic metabolites and pH of the in vitro model were evaluated throughout a 1440-min incubation period. CPI-613-containing treatments, with or without Avidin, decreased pH levels and increased glycogen degradation and lactate accumulation compared to the control and Avidin treatments (P < 0.05), indicating increased glycolytic flux. In a different experiment, two treatments, 400 µM CPI-613 or control, were employed to track the fates of pyruvate using [13C6]glucose. CPI-613 reduced the contribution of glucose carbon to tricarboxylic acid cycle intermediates compared to control (P < 0.05). To test whether the acceleration of acidification in reactions containing CPI-613 was due to an increase in the activity of key enzymes of glycogenolysis and glycolysis, we evaluated the activities of glycogen phosphorylase, phosphofructokinase, and pyruvate kinase in the presence or absence of 400 µM CPI-613. The CPI-613 treatment did not elicit an alteration in the activity of these three enzymes. These findings indicate that inhibiting PDH increases the rate of anaerobic glycolysis and pH decline, suggesting that mitochondria are potential regulators of postmortem metabolism.

CT analysis of skull contents in naturally mummified human corpses, a multicentric study.

INTRODUCTION: This study aimed to assess skull contents, brain appearance, and density on postmortem computed tomography in naturally mummified corpses. MATERIAL AND METHODS: For this purpose, a retrospective multicentric study, including mummified corpses from two French centers (Brest and Nantes) and from the New Mexico Decedent Image Database (USA), was performed by analyzing postmortem computed tomography (PMCT) focused on the head and neck of partially or fully mummified corpses discovered between 2011 and 2022. The PMCT analysis provided data on the CT appearance of brains, allowing them to be classified into four different categories (desiccation, liquefaction, dura mater only (DMO), and absence), and to measure densities (HU) of the brain remains. In addition, data on postmortem intervals (PMI) from Nantes and Brest centers were collected and analyzed to test the link between brain densities and PMIs. RESULTS: 54 cases of naturally mummified corpses were included. The brains were classified as liquefied (56%), desiccated (17 %), DMO (20 %), and absent (7 %) based on their CT appearance. Dehydrated brains were significantly (p < 0.004) denser (median 102 HU, interquartile range (IQR) 41) than either liquefied brains (median 39.5 HU, IQR 9) or brains with DMO (median -25 HU, IQR 57). However, the density of brain remains was not significantly affected by where the bodies were found (p = 0,41). Analysis of PMI and brain densities was performed on 22 cases. The results showed that brain remains were significantly (p = 0.039) denser when they were found after a PMI of more than six months. CONCLUSION: Brain desiccation was the aspect with the highest densities on PMCT, and for which we were able to highlight great preservation of anatomical structures observable in living organisms.

MEDICO-LEGAL APPLICATIONS OF FRACTURE HEMATOMA: REVIEW.

This review aimed to elucidate the critical role of fracture hematoma in forensic medicine, with a specific focus on its utility in differentiating antemortem from postmortem fractures. The study seeks to provide a comprehensive synthesis of current knowledge on the subject, highlighting the biological and medico-legal implications of fracture hematoma analysis in forensic investigations. A systematic review of literature was conducted, encompassing various scientific databases including PubMed, Scopus, and Web of Science, focusing on studies published from 2000 to 2024. The search employed keywords such as "fracture hematoma," "antemortem fractures," "perimortem fractures" and "postmortem fractures," among others, to explore relevant data. Selected studies were scrutinized based on their relevance, the presence of substantial data on fracture hematoma, and their contribution to forensic analysis. The review underscores the significance of fracture hematoma as an indicator of antemortem injuries, revealing that active blood circulation at the time of injury facilitates hematoma formation. Detailed analyses within the selected studies illustrate the interplay of cellular and molecular dynamics within fracture hematomas, emphasizing the roles of cytokines, particularly IL-6, and cellular constituents in the healing process. Fracture hematoma analysis emerges as a vital forensic tool in establishing the vitality of bone fractures, enhancing the accuracy of forensic assessments. However, the review also acknowledges the challenges posed by individual healing variability and postmortem changes, suggesting a need for further research to refine the interpretative frameworks used in forensic hematoma analysis.