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Italy and the United States are two of the countries most affected by SARS-CoV-2 (COVID-19), with more than 240,760 confirmed cases in Italy and 2,699,658 in the United States (as of July 2, 2020). The current COVID-19 pandemic has led to substantial changes in many fields of medicine, specifically in the forensic discipline. Medicolegal activities related to conducting autopsies have been largely affected by the COVID-19 pandemic. Postmortem examinations are generally discouraged by government regulations due to the risk of spreading the disease further through the handling and dissection of bodies from patients who succumbed to COVID-19 infection. There is a paucity of data regarding the persistence of SARS-CoV-2 in bodies, as well as concerning the reliability of swabbing methods in human remains. On the other hand, the autopsy is an essential tool to provide necessary information about the pathophysiology of the disease that presents useful clinical and epidemiological insights. On this basis, we aim to address issues concerning general medical examiner/coroner organization, comparing the Italian and American systems. We also discuss the pivotal roles of forensic pathologists in informing infectious disease surveillance. Finally, we focus on the impact of COVID-19 emergency on medicolegal practices in Italy and the United States, as well as the responses of the forensic scientific community to the emerging concerns related to the pandemic. We believe that stronger efforts by authorities are necessary to facilitate completing postmortem examinations, as data derived from such assessments are expected to be paramount to improving patient management and disease prevention.
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COVID-19/epidemiologia , Médicos Legistas , Papel Profissional , Autopsia , Doenças Transmissíveis/epidemiologia , Atestado de Óbito , Transmissão de Doença Infecciosa/prevenção & controle , Monitoramento Epidemiológico , Humanos , Controle de Infecções/normas , Itália/epidemiologia , Pandemias , Estados Unidos/epidemiologiaRESUMO
Death does not occur instantaneously and organs do not decompose at the same rate or in the same way. Nulligravid human uteri and prostate glands are the last internal organs to deteriorate during decomposition; however, the reason for this very important observation is still enigmatic. Recent studies have elucidated that the composition and abundance of microbes in the human thanatomicrobiome (microbiome of death) varies by organ and changes as a function of time and temperature. The ileocecal area has the largest absolute postmortem burden that spreads to the liver and spleen and continues to the heart and brain depending on the cause of death. To truly understand the mechanisms of microbial assembly during decomposition, a thorough examination of different strategies utilized by the trillions of microbes that colonize decaying tissues is needed from a multi-organ and multidisciplinary approach. In this review, we highlight interdisciplinary research and provide an overview of human decomposition investigations of thanatomicrobiomic changes in internal organs.
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Microbiota , Mudanças Depois da Morte , Fenômenos Fisiológicos Bacterianos , Translocação Bacteriana , Encéfalo/microbiologia , Encéfalo/patologia , Feminino , Patologia Legal , Coração/microbiologia , Humanos , Fígado/microbiologia , Fígado/patologia , Masculino , Miocárdio/patologia , Próstata/microbiologia , Próstata/patologia , Baço/microbiologia , Baço/patologia , Útero/microbiologia , Útero/patologiaRESUMO
This review is a journey of the landmark erythroblast macrophage protein (Emp) discovered in 1994, and it walks chronologically through the progress that has been made in understanding the biological function of this protein. Historically, Emp was the first identified cell attachment molecule and is expressed in both erythroblasts and macrophages and mediates their attachments to form erythroblastic islands. The absence of Emp erythroblasts shows defects in differentiation and enucleation. Emp-deficient macrophages display immature morphology characterized by small sizes, round shapes, and the lack of cytoplasmic projections. Although the primary sequence of Emp has already been determined and its role in both erythroid and macrophage development is well established, there are major gaps in the understanding of its function at the molecular level. Recent studies had implicated its importance in actin cytoskeleton remodeling and cell migration, but the molecular mechanisms are still enigmatic. Previous studies have also demonstrated that downregulation of Emp affects the expression of mitogen-associated protein kinase 1 (MAPK1) and thymoma viral protooncogene (AKT-1) resulting in abnormal cell motility. In this review, we summarize the proposed function of Emp based on previous studies, present scenarios, and its plausible future in translational research.
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Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Animais , Moléculas de Adesão Celular/química , Diferenciação Celular , Proteínas do Citoesqueleto/química , Eritroblastos/citologia , Eritroblastos/metabolismo , Eritropoese/genética , Humanos , Macrófagos/citologia , Macrófagos/imunologia , Macrófagos/metabolismo , Transporte ProteicoRESUMO
Erythroblast macrophage protein is a novel protein known to mediate attachment of erythroid cells to macrophages to form erythroblastic islands in bone marrow during erythropoiesis. Emp-null macrophages are small with round morphologies, and lack cytoplasmic projections which imply immature structure. The role of Emp in macrophage development and function is not fully elucidated. Macrophages perform varied functions (e.g. homeostasis, erythropoiesis), and are implicated in numerous pathophysiological conditions such as cellular malignancy. The objective of the current study is to investigate the interaction of Emp with cytoskeletal- and cell migration-associated proteins involved in macrophage functions. A short hairpin RNA lentiviral system was use to down-regulate the expression of Emp in macrophage cells. A cell migration assay revealed that the relocation of macrophages was significantly inhibited when Emp expression was decreased. To further analyze changes in gene expression related to cell motility, PCR array was performed by down-regulating Emp expression. The results indicated that expression of mitogen-activated protein kinase 1 and thymoma viral proto-oncogene 1 were significantly higher when Emp was down-regulated. The results implicate Emp in abnormal cell motility, thus, warrants to assess its role in cancer where tumor cell motility is required for invasion and metastasis.
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Moléculas de Adesão Celular/fisiologia , Movimento Celular/genética , Proteínas do Citoesqueleto/fisiologia , Animais , Medula Óssea/metabolismo , Medula Óssea/patologia , Adesão Celular , Moléculas de Adesão Celular/efeitos dos fármacos , Moléculas de Adesão Celular/metabolismo , Proteínas do Citoesqueleto/efeitos dos fármacos , Proteínas do Citoesqueleto/metabolismo , Eritroblastos/metabolismo , Eritroblastos/patologia , Células Eritroides/metabolismo , Eritropoese , Regulação da Expressão Gênica , Macrófagos/metabolismo , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteínas Proto-Oncogênicas c-akt/genética , Células RAW 264.7 , RNA Interferente Pequeno/farmacologiaRESUMO
Genomic studies have estimated there are approximately 10(3)-10(6) bacterial species per gram of soil. The microbial species found in soil associated with decomposing human remains (gravesoil) have been investigated and recognized as potential molecular determinants for estimates of time since death. The nascent era of high-throughput amplicon sequencing of the conserved 16S ribosomal RNA (rRNA) gene region of gravesoil microbes is allowing research to expand beyond more subjective empirical methods used in forensic microbiology. The goal of the present study was to evaluate microbial communities and identify taxonomic signatures associated with the gravesoil human cadavers. Using 16S rRNA gene amplicon-based sequencing, soil microbial communities were surveyed from 18 cadavers placed on the surface or buried that were allowed to decompose over a range of decomposition time periods (3-303 days). Surface soil microbial communities showed a decreasing trend in taxon richness, diversity, and evenness over decomposition, while buried cadaver-soil microbial communities demonstrated increasing taxon richness, consistent diversity, and decreasing evenness. The results show that ubiquitous Proteobacteria was confirmed as the most abundant phylum in all gravesoil samples. Surface cadaver-soil communities demonstrated a decrease in Acidobacteria and an increase in Firmicutes relative abundance over decomposition, while buried soil communities were consistent in their community composition throughout decomposition. Better understanding of microbial community structure and its shifts over time may be important for advancing general knowledge of decomposition soil ecology and its potential use during forensic investigations.
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Bactérias/isolamento & purificação , Bactérias/metabolismo , Restos Mortais/microbiologia , Microbiologia do Solo , Bactérias/classificação , Bactérias/genética , Biodiversidade , Cadáver , DNA Bacteriano/genética , Humanos , Filogenia , RNA Ribossômico 16S/genética , Solo/química , Fatores de TempoRESUMO
Most forensic research that is used to better understand how to estimate the postmortem interval (PMI) entails the study of the physiochemical characteristics of decomposition and the effects that environmental factors have on the decomposition process. Forensic entomology exploits the life cycles of arthropods like Diptera (blow flies or flesh flies) and Coleoptera (beetles) deposited on the decaying carcass to determine PMI. Forensic taphonomy, from the Greek word taphos meaning burial, studies the creation of the fossils of decomposed cadavers to ascertain information as to the nature and time of death. Compared to other areas of taphonomy, there have been relatively few forensic science studies that have investigated the impact of human decomposition on the microbial changes occurring on or in a corpse or in the soil communities underneath a body. Such research may facilitate the critical determination of PMI. Therefore, the scope of this review is to provide a concise summary of the current progress in the newly emerging field of microbial diversity and the next-generation metagenomic sequencing approaches for assessing these communities in humans and in the soil beneath decomposing human.
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Autopsia/métodos , Contagem de Colônia Microbiana/métodos , Mudanças Depois da Morte , Microbiologia do Solo , Humanos , Fatores de TempoRESUMO
Over the years, there have been numerous formulas proposed for use in determining the postmortem interval (PMI); however, no method is all encompassing and absolute. Even so, very little research has been undertaken to determine if there is a viable correlation between the rate of DNA degradation and PMI, which can be calculated from analysis by flow cytometry. In this study, we analyzed the rate of DNA degradation of spleen and brain tissues from 15 cadavers over a 96-hour period of time at 2 temperature conditions, that is, 21°C (room temperature) and 4°C (refrigerator) to mimic summer and winter weather, respectively. The resulting data were used to form a pattern that correlates DNA degradation to cell death occurrence. Statistical analyses were performed to determine the significance of the relationship between PMI and DNA degradation. Moreover, in search of alternative reliable organs of interest for PMI estimation, the results demonstrate that the brain has lesser DNA degradation as compared with the spleen. Thus, the current study suggests that the brain can be an organ of choice for PMI studies, but more research is underway in this aspect.
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Química Encefálica , Degradação Necrótica do DNA , Citometria de Fluxo , Mudanças Depois da Morte , Baço/química , Adolescente , Adulto , Idoso , Encéfalo/patologia , Cadáver , Morte Celular , Feminino , Genética Forense , Patologia Legal , Humanos , Masculino , Pessoa de Meia-Idade , Manejo de Espécimes , Baço/patologia , Temperatura , Adulto JovemRESUMO
Gene expression investigations are well-established components of ante mortem studies with broad applications ranging from elucidating basic mechanisms responsible for normal physiological processes to discovering therapeutic targets in pathophysiological conditions. However, gene expression studies and their application in the medico-legal field are still in their infancy. Therefore, the present study focuses on RNA using PCR array in the analysis of gene expression associated with tissues taken from actual criminal cases. RNA was extracted from the liver tissues of bodies with PMIs between 6 and 48 h. The results demonstrated that mRNA was stable up to 48 h postmortem. Further, as cell death is an indispensable and necessary part of the biological life cycle, apoptotic gene expression profiles were investigated. The gene expression related to the programmed cell death found in body tissues after death is defined as the apoptotic thanatotranscriptome (thanatos-, Greek for death). On comparison of control and decaying tissues, the results show that with time, pro-apoptotic genes such as caspases are up-regulated and the expression of genes responsible for anti-apoptosis such as BCL2 and BAG3 were down-regulated. Thus, this current work gives a unique perspective of the apoptotic thanatotranscriptome that is affected after death. Up to the present time, gene expression in bodies from criminal cases has not been reported in literature using PCR array techniques. Thus, this thanatotranscriptome study provides insight into postmortem gene activity with potential applications in medico-legal investigations.
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Apoptose/genética , Perfilação da Expressão Gênica , Fígado/patologia , Mudanças Depois da Morte , Transcriptoma , Proteínas Reguladoras de Apoptose/genética , Cadáver , Regulação para Baixo , Humanos , Reação em Cadeia da Polimerase , RNA Mensageiro/metabolismo , Regulação para CimaRESUMO
Human death is a complex, time-governed phenomenon that leads to the irreversible cessation of all bodily functions. Recent molecular and genetic studies have revealed remarkable experimental evidence of genetically programmed cellular death characterized by several physiological processes; however, the basic physiological function that occurs during the immediate postmortem period remains inadequately described. There is a paucity of knowledge connecting necrotic pathologies occurring in human organ tissues to complete functional loss of the human organism. Cells, tissues, organs, and organ systems show a range of differential resilience and endurance responses that occur during organismal death. Intriguingly, a persistent ambiguity in the study of postmortem physiological systems is the determination of the trajectory of a complex multicellular human body, far from life-sustaining homeostasis, following the gradual or sudden expiry of its regulatory systems. Recent groundbreaking investigations have resulted in a paradigm shift in understanding the cell biology and physiology of death. Two significant findings are that (i) most cells in the human body are microbial, and (ii) microbial cell abundance significantly increases after death. By addressing the physiological as well as the microbiological aspects of death, future investigations are poised to reveal innovative insights into the enigmatic biological activities associated with death and human decomposition. Understanding the elaborate crosstalk of abiotic and biotic factors in the context of death has implications for scientific discoveries important to informing translational knowledge regarding the transition from living to the non-living. There are important and practical needs for a transformative reestablishment of accepted models of biological death (i.e., artificial intelligence, AI) for more precise determinations of when the regulatory mechanisms for homeostasis of a living individual have ceased. In this review, we summarize mechanisms of physiological, genetic, and microbiological processes that define the biological changes and pathways associated with human organismal death and decomposition.
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Introduction: The fact that SARS-CoV-2, the coronavirus that caused COVID-19, can translocate within days of infection to the brain and heart and that the virus can survive for months is well established. However, studies have not investigated the crosstalk between the brain, heart, and lungs regarding microbiota that simultaneously co-inhabit these organs during COVID-19 illness and subsequent death. Given the significant overlap of cause of death from or with SARS-CoV-2, we investigated the possibility of a microbial fingerprint regarding COVID-19 death. Methods: In the current study, the 16S rRNA V4 region was amplified and sequenced from 20 COVID-19-positive and 20 non-COVID-19 cases. Nonparametric statistics were used to determine the resulting microbiota profile and its association with cadaver characteristics. When comparing non-COVID-19 infected tissues versus those infected by COVID-19, there is statistical differences (p < 0.05) between organs from the infected group only. Results: When comparing the three organs, microbial richness was significantly higher in non-COVID-19-infected tissues than infected. Unifrac distance metrics showed more variance between control and COVID-19 groups in weighted analysis than unweighted; both were statistically different. Unweighted Bray-Curtis principal coordinate analyses revealed a near distinct two-community structure: one for the control and the other for the infected group. Both unweighted and weighted Bray-Curtis showed statistical differences. Deblur analyses demonstrated Firmicutes in all organs from both groups. Discussion: Data obtained from these studies facilitated the defining of microbiome signatures in COVID-19 decedents that could be identified as taxonomic biomarkers effective for predicting the occurrence, the co-infections involved in its dysbiosis, and the evolution of the virus.
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The decomposition of a body is inseparably associated with the release of several types of odors. This phenomenon has been used in the training of sniffer dogs for decades. The odor profile associated with decomposition consists of a range of volatile organic compounds (VOCs), chemical composition of which varies over time, temperature, environmental conditions, and the type of microorganisms, and insects colonizing the carcass. Mercaptans are responsible for the bad smell associated with corpses; however, there are no unified recommendations for conducting forensic analysis based on the detectable odor of revealed corpses and previous research on VOCs shows differing results. The aim of this review is to systematize the current knowledge on the type of volatile organic compounds related to the decomposition process, depending on a few variables. This knowledge will improve the methods of VOCs detection and analysis to be used in modern forensic diagnostics and improve the methods of training dogs for forensic applications.
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Forensic laboratories are required to have analytical tools to confidently differentiate illegal substances such as marijuana from legal products (i.e., industrial hemp). The Achilles heel of industrial hemp is its association with marijuana. Industrial hemp from the Cannabis sativa L. plant is reported to be one of the strongest natural multipurpose fibers on earth. The Cannabis plant is a vigorous annual crop broadly separated into two classes: industrial hemp and marijuana. Up until the eighteenth century, hemp was one of the major fibers in the United States. The decline of its cultivation and applications is largely due to burgeoning manufacture of synthetic fibers. Traditional composite materials such as concrete, fiberglass insulation, and lumber are environmentally unfavorable. Industrial hemp exhibits environmental sustainability, low maintenance, and high local and national economic impacts. The 2018 Farm Bill made way for the legalization of hemp by categorizing it as an ordinary agricultural commodity. Unlike marijuana, hemp contains less than 0.3% of the cannabinoid, Δ9-tetrahydrocannabinol, the psychoactive compound which gives users psychotropic effects and confers illegality in some locations. On the other hand, industrial hemp contains cannabidiol found in the resinous flower of Cannabis and is purported to have multiple advantageous uses. There is a paucity of investigations of the identity, microbial diversity, and biochemical characterizations of industrial hemp. This review provides background on important topics regarding hemp and the quantification of total tetrahydrocannabinol in hemp products. It will also serve as an overview of emergent microbiological studies regarding hemp inflorescences. Further, we examine challenges in using forensic analytical methodologies tasked to distinguish legal fiber-type material from illegal drug-types.
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The microbiota gut-brain-axis is a bidirectional circuit that links the neural, endocrine, and immunological systems with gut microbial communities. The gut microbiome plays significant roles in human mind and behavior, specifically pain perception, learning capacity, memory, and temperament. Studies have shown that disruptions in the gut microbiota have been associated with substance use disorders. The interplay of gut microbiota in substance abuse disorders has not been elucidated; however, postmortem microbiome profiles may produce promising avenues for future forensic investigations. The goal of the current study was to determine gut microbiome composition in substance abuse disorder cases using transverse colon tissues of 21 drug overdose versus 19 non-overdose-related cases. We hypothesized that postmortem samples of the same cause of death will reveal similar microbial taxonomic relationships. We compared microbial diversity profiles using amplicon-based sequencing of the 16S rRNA gene V4 hypervariable region. The results demonstrated that the microbial abundance in younger-aged cases were found to have significantly more operational taxonomic units than older cases. Using weighted UniFrac analysis, the influence of substances in overdose cases was found to be a significant factor in determining microbiome similarity. The results also revealed that samples of the same cause of death cluster together, showing a high degree of similarity between samples and a low degree of similarity among samples of different causes of death. In conclusion, our examination of human transverse colon microflora in decomposing remains extends emerging literature on postmortem microbial communities, which will ultimately contribute to advanced knowledge of human putrefaction.
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Microbioma Gastrointestinal , Microbiota , Transtornos Relacionados ao Uso de Substâncias , Idoso , Microbioma Gastrointestinal/genética , Humanos , Microbiota/genética , Mudanças Depois da Morte , RNA Ribossômico 16S/análise , RNA Ribossômico 16S/genéticaRESUMO
Aim: The study aimed to examine whether volatile substances (ethanol, isopropanol, and acetone) can be detected in costal cartilage and also if concentrations of detected substances reliably reflect their concentrations in the peripheral blood - the standard forensic material for toxicological analyses. Such knowledge can be useful in cases when a cadaver's blood is unavailable or contaminated. Material and methods: Ethanol, isopropanol, and acetone concentrations were determined in samples of unground costal cartilage (UCC), ground costal cartilage (GCC), femoral venous blood, and urine. The samples were analysed by gas chromatography (GC) with a flame ionization detector using headspace analysis. Results: Volatile substances were detected in 12 out of 100 analysed samples. There was a strong positive correlation between ethanol concentration in the blood and urine (r = 0.899, p < 0.001), UCC (r = 0.809, p < 0.01), and GCC (r = 0.749, p < 0.01). A similar strong correlation was found for isopropanol concentration in the blood and urine (r = 0.979, p < 0.001), UCC (r = 0.866, p < 0.001), and GCC (r = 0.942, p < 0.001). Acetone concentration in the blood strongly correlated only with its concentration in urine (r = 0.960, p < 0.001). Conclusions: We demonstrated for the first time the possibility of detecting volatile substances: ethanol, isopropanol and acetone in a human costal cartilage. Also, the study showed that higher volatiles concentrations were better determined in ground samples.
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Gene expression is the process by which DNA is decoded to produce a functional transcript. The collection of all transcripts is referred to as the transcriptome and has extensively been used to evaluate differentially expressed genes in a certain cell or tissue type. In response to internal or external stimuli, the transcriptome is greatly regulated by epigenetic changes. Many studies have elucidated that antemortem gene expression (transcriptome) may be linked to an array of disease etiologies as well as potential targets for drug discovery; on the other hand, a number of studies have utilized postmortem gene expression (thanatotranscriptome) patterns to determine cause and time of death. The "transcriptome after death" involves the study of mRNA transcripts occurring in human tissues after death (thanatos, Greek for death). While antemortem gene expression can provide a wide range of important information about the host, the determination of the communication of genes after a human dies has recently been explored. After death a plethora of genes are regulated via activation versus repression as well as diverse regulatory factors such as the absence or presence of stimulated feedback. Even postmortem transcriptional regulation contains many more cellular constituents and is massively more complicated. The rates of degradation of mRNA transcripts vary depending on the types of postmortem tissues and their combinatorial gene expression signatures. mRNA molecules have been shown to persist for extended time frames; nevertheless, they are highly susceptible to degradation, with half-lives of selected mRNAs varying between minutes to weeks for specifically induced genes. Furthermore, postmortem genetic studies may be used to improve organ transplantation techniques. This review is the first of its kind to fully explore both gene expression and mRNA stability after death and the trove of information that can be provided about phenotypical characteristics of specific genes postmortem.
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Morte , Vida , Mudanças Depois da Morte , Transcriptoma/genética , Animais , Autopsia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Estilo de Vida , Estabilidade de RNA , RNA Mensageiro/análise , RNA Mensageiro/genéticaRESUMO
Corals' obligate association with unicellular dinoflagellates, family Symbiodiniaceae form the foundation of coral reefs. For nearly a century, researchers have delved into understanding the coral-algal mutualism from multiple levels of resolution and perspectives, and the questions and scope have evolved with each iteration of new techniques. Advances in genetic technologies not only aided in distinguishing between the multitude of Symbiodiniaceae but also illuminated the existence and diversity of other organisms constituting the coral microbiome. The coral therefore is a meta-organism, often referred to as the coral holobiont. In this review, we address the importance of including a holistic perspective to understanding the coral holobiont. We also discuss the ramifications of how different genotypic combinations of the coral consortium affect the holobiont entity. We highlight the paucity of data on most of the coral microbiome. Using Symbiodiniaceae data, we present evidence that the holobiont properties are not necessarily the sum of its parts. We then discuss the consequences of the holobiont attributes to the fitness of the holobiont and the myriad of organisms that contribute to it. Considering the complexity of host-symbiont genotypic combinations will aid in our understanding of coral resilience, robustness, acclimation, and/or adaptation in the face of environmental change and increasing perturbations.
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We report a unique case of post-traumatic pulmonary food embolism, due to a lethal blunt force trauma occurred in a traffic accident. The subject was a 37-year old man, victim of a road traffic accident while he was riding his motorbike. A forensic autopsy, followed by histological examination, was ordered in order to find out the cause of death and to assess the compatibility of the lesions with the dinamic of the accident. Autopsy revealed a blunt force thoraco-abdominal trauma responsible of the death. The most interesting histological evidences concerned lungs. Here, inside arterious and arteriolar pulmonary vessels, we identified crystal-like corpuscles, of various shape and size, sometimes aggregated in small masses and thin vegetal fibers, refracting at polarized light, both PAS-positive and meat fibers shadows. The presence of alimentary material in the pulmonary vessels was explained by a pulmonary food embolism. The occurring of this kind of embolism implies a communication between the viscera lumen and the venous circulation of his wall (through a small wall rupture) in presence of cardiocirculatory activity, and provides, therefore, a strong proof of vitality.
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Traumatismos Abdominais/complicações , Pulmão/patologia , Embolia Pulmonar/etiologia , Traumatismos Torácicos/complicações , Ferimentos não Penetrantes/complicações , Acidentes de Trânsito , Adulto , Autopsia , Alimentos , Humanos , MasculinoRESUMO
Thanatotranscriptome studies involve the examination of mRNA transcript abundance and gene expression patterns in the internal organs of deceased humans. Postmortem gene expression is indicative of the cellular status of a corpse at the time of death, a portion of which may represent a cascade of molecular events occasioned by death. Specific gene biomarkers identify perceptible transcriptional changes induced by stochastic responses to the cessation of biological functions. Transcriptome analyses of postmortem mRNA from a tissue fragment may determine unique molecular identifiers for specific organs and demonstrate unique patterns of gene expression that can provide essential contextual anatomical information. We evaluated the impact of targeted transcriptome analysis using RNA sequencing to reveal global changes in postmortem gene expression in liver tissues from 27 Italian and United States corpses: 3.5-hour-old to 37-day-old. We found that our single blind study using eight liver tissue-specific gene biomarkers (e.g. AMBP and AHSG) is highly specific, with autopsy-derived organ samples correctly identified as tissues originating from postmortem livers. The results demonstrate that 98-100% of sequencing reads were mapped to these liver biomarkers. Our findings indicate that gene expression signatures of mRNA exposed up to 37 days of autolysis, can be used to validate the putative identity of tissue fragments.
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Identificação Biométrica/métodos , Fígado/metabolismo , RNA Mensageiro/genética , Transcriptoma , Adulto , Idoso , Idoso de 80 Anos ou mais , Autopsia , Cadáver , Feminino , Ciências Forenses , Perfilação da Expressão Gênica , Marcadores Genéticos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Fígado/química , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/classificação , RNA Mensageiro/metabolismoRESUMO
Human thanatomicrobiota studies have shown that microorganisms inhabit and proliferate externally and internally throughout the body and are the primary mediators of putrefaction after death. Yet little is known about the source and diversity of the thanatomicrobiome or the underlying factors leading to delayed decomposition exhibited by reproductive organs. The use of the V4 hypervariable region of bacterial 16S rRNA gene sequences for taxonomic classification ("barcoding") and phylogenetic analyses of human postmortem microbiota has recently emerged as a possible tool in forensic microbiology. The goal of this study was to apply a 16S rRNA barcoding approach to investigate variation among different organs, as well as the extent to which microbial associations among different body organs in human cadavers can be used to predict forensically important determinations, such as cause and time of death. We assessed microbiota of organ tissues including brain, heart, liver, spleen, prostate, and uterus collected at autopsy from criminal casework of 40 Italian cadavers with times of death ranging from 24 to 432 h. Both the uterus and prostate had a significantly higher alpha diversity compared to other anatomical sites, and exhibited a significantly different microbial community composition from non-reproductive organs, which we found to be dominated by the bacterial orders MLE1-12, Saprospirales, and Burkholderiales. In contrast, reproductive organs were dominated by Clostridiales, Lactobacillales, and showed a marked decrease in relative abundance of MLE1-12. These results provide insight into the observation that the uterus and prostate are the last internal organs to decay during human decomposition. We conclude that distinct community profiles of reproductive versus non-reproductive organs may help guide the application of forensic microbiology tools to investigations of human cadavers.
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Exosomes play a crucial role in the progression of infectious diseases, as exosome release and biogenesis are affected by external factors, such as pathogenic infections. Pyrogens may aide in the progression of diseases by triggering inflammation, endothelial cell injury, and arterial plaque rupture, all of which can lead to acute coronary disease, resulting in cardiac tissue death and the onset of a cardiac event (CE). To better understand the effects of Gram-negative bacterial infections on exosome composition and biogenesis, we examined exosome characteristics after treatment of AC16 human cardiomyocytes with lipopolysaccharide (LPS), which served as a model system for Gram-negative bacterial infection. Using increasing doses (0, 0.1, 1, or 10 µg) of LPS, we showed that treatment with LPS substantially altered the composition of AC16-derived exosomes. Both the relative size and the quantity (particles/mL) of exosomes were decreased significantly at all tested concentrations of LPS treatment compared to the untreated group. In addition, LPS administration reduced the expression of exosomal proteins that are related to exosomal biogenesis. Conversely, we observed an increase in immunomodulators present after LPS administration. This evaluation of the impact of LPS on cardiac cell death and exosome composition will yield new insight into the importance of exosomes in a variety of physiological and pathological processes as it relates to disease progression, diagnosis, and treatment.