Golgi localization of SARS-CoV-2 spike protein and interaction with furin in cerebral COVID-19 microangiopathy: a clue to the central nervous system involvement?

In a neuropathological series of 20 COVID-19 cases, we analyzed six cases (three biopsies and three autopsies) with multiple foci predominantly affecting the white matter as shown by MRI. The cases presented with microhemorrhages evocative of small artery diseases. This COVID-19 associated cerebral microangiopathy (CCM) was characterized by perivascular changes: arterioles were surrounded by vacuolized tissue, clustered macrophages, large axonal swellings and a crown arrangement of aquaporin-4 immunoreactivity. There was evidence of blood-brain-barrier leakage. Fibrinoid necrosis, vascular occlusion, perivascular cuffing and demyelination were absent. While no viral particle or viral RNA was found in the brain, the SARS-CoV-2 spike protein was detected in the Golgi apparatus of brain endothelial cells where it closely associated with furin, a host protease known to play a key role in virus replication. Endothelial cells in culture were not permissive to SARS-CoV-2 replication. The distribution of the spike protein in brain endothelial cells differed from that observed in pneumocytes. In the latter, the diffuse cytoplasmic labeling suggested a complete replication cycle with viral release, notably through the lysosomal pathway. In contrast, in cerebral endothelial cells the excretion cycle was blocked in the Golgi apparatus. Interruption of the excretion cycle could explain the difficulty of SARS-CoV-2 to infect endothelial cells in vitro and to produce viral RNA in the brain. Specific metabolism of the virus in brain endothelial cells could weaken the cell walls and eventually lead to the characteristic lesions of COVID-19 associated cerebral microangiopathy. Furin as a modulator of vascular permeability could provide some clues for the control of late effects of microangiopathy.

Infection of lung megakaryocytes and platelets by SARS-CoV-2 anticipate fatal COVID-19.

SARS-CoV-2, although not being a circulatory virus, spread from the respiratory tract resulting in multiorgan failures and thrombotic complications, the hallmarks of fatal COVID-19. A convergent contributor could be platelets that beyond hemostatic functions can carry infectious viruses. Here, we profiled 52 patients with severe COVID-19 and demonstrated that circulating platelets of 19 out 20 non-survivor patients contain SARS-CoV-2 in robust correlation with fatal outcome. Platelets containing SARS-CoV-2 might originate from bone marrow and lung megakaryocytes (MKs), the platelet precursors, which were found infected by SARS-CoV-2 in COVID-19 autopsies. Accordingly, MKs undergoing shortened differentiation and expressing anti-viral IFITM1 and IFITM3 RNA as a sign of viral sensing were enriched in the circulation of deadly COVID-19. Infected MKs reach the lung concomitant with a specific MK-related cytokine storm rich in VEGF, PDGF and inflammatory molecules, anticipating fatal outcome. Lung macrophages capture SARS-CoV-2-containing platelets in vivo. The virus contained by platelets is infectious as capture of platelets carrying SARS-CoV-2 propagates infection to macrophages in vitro, in a process blocked by an anti-GPIIbIIIa drug. Altogether, platelets containing infectious SARS-CoV-2  alter COVID-19 pathogenesis and provide a powerful fatality marker. Clinical targeting of platelets might prevent viral spread, thrombus formation and exacerbated inflammation at once and increase survival in COVID-19.

COVID-19 Lung Pathogenesis in SARS-CoV-2 Autopsy Cases.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a major public health issue. COVID-19 is considered an airway/multi-systemic disease, and demise has been associated with an uncontrolled immune response and a cytokine storm in response to the virus. However, the lung pathology, immune response, and tissue damage associated with COVID-19 demise are poorly described and understood due to safety concerns. Using post-mortem lung tissues from uninfected and COVID-19 deadly cases as well as an unbiased combined analysis of histology, multi-viral and host markers staining, correlative microscopy, confocal, and image analysis, we identified three distinct phenotypes of COVID-19-induced lung damage. First, a COVID-19-induced hemorrhage characterized by minimal immune infiltration and large thrombus; Second, a COVID-19-induced immune infiltration with excessive immune cell infiltration but no hemorrhagic events. The third phenotype correspond to the combination of the two previous ones. We observed the loss of alveolar wall integrity, detachment of lung tissue pieces, fibroblast proliferation, and extensive fibrosis in all three phenotypes. Although lung tissues studied were from lethal COVID-19, a strong immune response was observed in all cases analyzed with significant B cell and poor T cell infiltrations, suggesting an exhausted or compromised immune cellular response in these patients. Overall, our data show that SARS-CoV-2-induced lung damage is highly heterogeneous. These individual differences need to be considered to understand the acute and long-term COVID-19 consequences.

Committing Suicide With Handgun Wounds in the Head Using a Defective Firearm: About 2 Unusual Autopsy Cases.

We report 2 unusual autopsy cases with head handgun wounds using defective firearms in a suicidal context. In the first case, a 78-year-old man was found hanged from a tree, with a Lefaucheux revolver lying on the tree. In the right temporal region, there was an entrance wound with a bullet still in place, responsible for a mild cerebral contusion, without bone defect. The main cause of death was hanging. In the second case, a 60-year-old man died at home after shooting himself in the head several times with a 22-long rifle revolver. The autopsy showed 13 entrance wounds on the scalp. Most of the bullets remained along the skull vault. In each of 2 cases, the manner of death, the feasibility of suicidal gesture, and the consequences of a brain injury on the time to the occurrence of incapacity were questioned. These unusual autopsy cases underline how important it is to take into account the defective nature of firearms.

Suicide and Microglia: Recent Findings and Future Perspectives Based on Human Studies.

Suicide is one of the most disastrous outcomes for psychiatric disorders. Recent advances in biological psychiatry have suggested a positive relationship between some specific brain abnormalities and specific symptoms in psychiatric disorders whose organic bases were previously completely unknown. Microglia, immune cells in the brain, are regarded to play crucial roles in brain inflammation by releasing inflammatory mediators and are suggested to contribute to various psychiatric disorders such as depression and schizophrenia. Recently, activated microglia have been suggested to be one of the possible contributing cells to suicide and suicidal behaviors via various mechanisms especially including the tryptophan-kynurenine pathway. Animal model research focusing on psychiatric disorders has a long history, however, there are only limited animal models that can properly express psychiatric symptoms. In particular, to our knowledge, animal models of human suicidal behaviors have not been established. Suicide is believed to be limited to humans, therefore human subjects should be the targets of research despite various ethical and technical limitations. From this perspective, we introduce human biological studies focusing on suicide and microglia. We first present neuropathological studies using the human postmortem brain of suicide victims. Second, we show recent findings based on positron emission tomography (PET) imaging and peripheral blood biomarker analysis on living subjects with suicidal ideation and/or suicide-related behaviors especially focusing on the tryptophan-kynurenine pathway. Finally, we propose future perspectives and tasks to clarify the role of microglia in suicide using multi-dimensional analytical methods focusing on human subjects with suicidal ideation, suicide-related behaviors and suicide victims.

Development of a sensitive untargeted liquid chromatography-high resolution mass spectrometry screening devoted to hair analysis through a shared MS2 spectra database: A step toward early detection of new psychoactive substances.

Untargeted liquid chromatography-high resolution mass spectrometry (LC-HRMS) techniques have become indispensable tools for systematic toxicological analysis. They allow the research of an almost unlimited number of drugs within a single analytical cycle, but shared mass spectra libraries are still missing to identify newly marketed compounds, along with defined analytical procedures. This article describes the optimization, validation, and application of an untargeted screening method devoted to hair analysis using data-dependent analysis (DDA) and a shared HRMS database. This method used an ultra-high performance liquid chromatography coupled to a benchtop Orbitrap. Raw MS data were processed with Compound Discoverer software coupled to the mzCloud™ library. Optimizations were performed on blank hair spiked with 19 analytes having different physical and chemical properties. To validate the effectiveness of a shared spectra database, 20 compounds spectra were added and then retrospectively screened. Sensitivity and reliability were evaluated on 317 compounds of interest in toxicology. The method was then applied to 11 hair samples. The matrix effect range by ion suppression/enhancement was 40%-110%. The method allows the detection of 284 among the 317 screened compounds, including 72 new psychoactive substances (NPS). Lower limit of identification (LLOI) and lower limit of detection (LLOD) were 1 to 1000 pg/mg and 1 to 500 pg/mg, respectively. The method was successfully applied to 11 clinical cases and 144 compounds were identified including 24 NPS including AKB48-5F for the first time in hair. We developed and validated an LC-HRMS untargeted screening of 284 compounds and successfully applied it to 11 real hair samples.

Intimate Partner Violence: A Rare Case of Reciprocal Homicide.

We present the case of a reciprocal homicide by stabbing that occurred within an unmarried couple without known history of spousal violence. Each partner killed the other one at the same time and at the same place using kitchen knives. They were both found dead at home lying on the floor after the neighbors heard an argument and screams coming from the couple's apartment, so they called the police and the fire department. The door was locked from the inside, and the fire department was forced to break the door. Two kitchen knives supporting blood traces were found at the scene. At autopsy, both bodies showed multiple stab wounds, and the lethal ones were due to heart injuries. Defense injuries were also found in both bodies. To our knowledge, this is the first case of reciprocal homicide described in the literature. Other manners of death are discussed, including homicide by a third party, homicide-suicide, and suicide pact.

Undetermined Manner of Death: An Autopsy Series.

A manner of death may be ruled undetermined by the forensic pathologist when there is insufficient information about the circumstances surrounding the death to make a ruling. The aim of our study was to retrospectively analyze a series of autopsy cases that were classified as undetermined manner of death after complete investigations. In all, 48 cases were examined. In 23 cases (48%), the cause of death was determined. The most frequent cause of death was toxic death (n = 11). More than one manner of death was deemed conceivable for most cases (n = 39). The most frequent and the most probable manner of death was accident (n = 37). Homicide was not excluded in about 23% of the cases. Our study showed that the manner of death may remain undetermined despite an established cause of death, and even when two or more conceivable causes of death are considered. Our study pointed out that undetermined manner of death covers a wide range of situations and that homicide may be underestimated.

Sudden adult death: an autopsy series of 534 cases with gender and control comparison.

The aim of our study was to highlight the epidemiological difference in adult sudden death between males and females. The type of pathologies found in adult victims of sudden death was compared to control cases in order to determine the most significant pathologies involved in sudden death. Among all autopsies performed between 1995 and 2009, 534 adult cases of sudden death and 154 cases who violently died were respectively selected. For each case, a complete autopsy was carried out, including systematic histological examination of all major organs. The sudden death population was composed of 369 males and 165 females. There was no statistical difference regarding age between males and female. Sudden death took place more often at home in women than in men (p < 0.0001). A stressful event was more frequently found in men than in women (p = 0.03). Deaths caused by cardiovascular diseases were more frequent in males than in females, especially Coronary Artery Disease (CAD) (p < 0.0001). Cardiomyopathy was more often the cause of death in women, particularly Arrythmogenic Right Ventricular Cardiomyopathy (ARVC). Cardiac pathologies were found in 45% of the control cases. CAD and ARVC were statistically more frequent in the sudden death group than in the control group. According to our study, profile of sudden death is different between males and females. Those data seem to be important for clinicians involved in prevention programs of sudden death, as they can adapt their screening according to the gender.

Discriminating factors in fatal blunt trauma from low level falls and homicide.

PURPOSE: Determination of the manner of death is a major issue in forensic practice. Differentiating the injuries caused by falls from a low height from injuries due to the deliberate application of a blunt object can be difficult. A few studies suggested the use of certain criteria, such as the hat brim line rule, to help in differentiating between falls and blows. Unfortunately they are not consistent. METHODS: All autopsy cases from a 16-year period (1996-2012) were analyzed retrospectively. Three groups were defined: homicide cases (n = 31), sudden natural deaths involving a fall (n = 103), and accidental fall cases (n = 30). The three groups were statistically compared across a wide range of parameters including general characteristics, presence, and characteristics of different types of wounds (lacerations, deep bruises, fractures, intracranial trauma, and defense injuries) as well as their respective anatomical site. RESULTS: There were marked differences in wounds between homicide and fall cases, e.g., wounds were more numerous and larger in homicides. We did not confirm the hat brim line rule as a reliable discriminating parameter. A simple and highly effective multivariate model was found, which included the presence of lacerations, deep bruises, and intracranial trauma. CONCLUSION: This study underlines the importance of autopsy findings in providing an indication of the manner of death. Conversely, the limitations of the hat brim line rule have been highlighted.

[Contribution of the TUNEL method for post-mortem interval estimation: an experimental study]. / Apport de la méthode TUNEL dans l'estimation du délai post-mortem : une étude expérimentale.

The assessment of post-mortem interval is of major importance in forensic pathology. Many methods have been used in the early post-mortem period but remain rough. To test the hypothesis of an increased rate of apoptosis increasing with post-mortem interval, TUNEL method was applied in rats to study the relationship between the number of apoptotic cells in skin samples and the post-mortem interval. Our study showed that the post-mortem processes were associated with apoptosis in skin cells. The apoptosis rate was statistically correlated with post-mortem interval in the early post-mortem (less than 48 hours after death). The application of the TUNEL method for estimating the post-mortem interval in forensic pathology is discussed.

Homicidal deaths in the Western suburbs of Paris: a 15-year-study.

The aim of our study was to analyze the homicide pattern in the Western suburbs of Paris and its evolution between 1994 and 2008. All autopsy reports regarding homicides from the period January 1, 1994, to December 31, 2008, were retrospectively reviewed. Five hundred eleven homicide cases were selected of 4842 autopsy cases. The following data were recorded: assailants and victims characteristics, crime scene location, homicide motive, cause of death, and victim's postmortem toxicological results. Homicide rate steadily declined over the period at the exception of the number of homicide-suicide per year, which remained constant. Homicide victims remained unidentified after medicolegal investigations in 2% of the cases. Child and elder homicide cases represented, respectively, 10.7% and 8.2% of the cases. Offenders were male in 88% of the cases. Male and female assailants showed distinct homicide patterns: females were involved more frequently in familial quarrel and child abuse. They never killed a stranger and committed homicide exclusively in a private place with a predominance of sharp weapons. Males, in contrast, assaulted almost equally a stranger or an acquaintance, often in a public place with a predominance of firearm. Victim knew the assailant(s) in 57% of the cases. Homicides mostly took place at the residence of the assailant or the victim. Homicide motive was clearly determined in 71% of the cases. Argument was the most common motive in 44% of the cases. Sexual assault was rarely found (10 cases). Gunshot wounds were the most common cause of death (37%), followed by stab wounds (27%), blunt trauma (19%), and asphyxia (13%). A decrease of gunshot wounds as a cause of death was found over the studied period. Alcohol was the most common toxic detected in blood of the victim, in 48.5% of the cases when toxicological results were available. Blood alcohol concentration ranged from 1 to 500 mg/dL with a mean value of 150 mg/dL.

[How to complete a death certificate?]. / Comment bien remplir un certificat de décès?

The death certificate, an obligatory civil act, engaging the practitioner's responsability, and with administrative, judicial, familial and statistical issues, often raises problems for the physician. We will see in this article how to avoid any error and/or approximation, basing these advices and comments on a retrospective study on 100 analyzed certificates, and 30 interviewed practitioners.

[Gunshot wounds: forensic pathology]. / Blessures par projectile d'arme à feu : aspects anatomopathologiques.

Gunshot wounds are among the most complex traumatic lesions encountered in forensic pathology. At the time of autopsy, careful scrutiny of the wounds is essential for correct interpretation of the lesions. Complementary pathological analysis has many interests: differentiation between entrance and exit wounds, estimation of firing distance, differentiation between vital and post mortem wounds and wounds dating. In case of multiple headshots, neuropathological examination can provide arguments for or against suicide. Sampling of gunshot wounds at autopsy must be systematic. Pathological data should be confronted respectively to autopsy and death scene investigation data and also ballistic studies. Forensic pathologist must be aware of the limits of optic microscopy.

Changes in CRH and ACTH synthesis during experimental and human septic shock.

CONTEXT: The mechanisms of septic shock-associated adrenal insufficiency remain unclear. This study aimed at investigating the synthesis of corticotropin-releasing hormone (CRH) and vasopressin (AVP) by parvocellular neurons and the antehypophyseal expression of ACTH in human septic shock and in an experimental model of sepsis. OBJECTIVE: To test the hypothesis that ACTH secretion is decreased secondarily to alteration of CRH or AVP synthesis, we undertook a neuropathological study of the antehypophyseal system in patients who had died from septic shock and rats with experimental faecal peritonitis. METHODS: Brains obtained in 9 septic shock patients were compared to 10 nonseptic patients (controls). Parvocellular expression of AVP and CRH mRNA were evaluated by in situ hybridization. Antehypophyseal expression of ACTH, vasopressin V1b and CRH R1 receptors and parvocellular expression of iNOS in the PVN were evaluated by immunohistochemistry. The same experiments were carried out in a fecal peritonitis-induced model of sepsis. Data from septic rats with (n = 6) or without (n = 10) early death were compared to sham-operated (n = 8) animals. RESULTS: In patients and rats, septic shock was associated with a decreased expression of ACTH, unchanged expression of V1B receptor, CRHR1 and AVP mRNA, and increased expression of parvocellular iNOS compared to controls. Septic shock was also characterized by an increased expression of CRH mRNA in rats but not in patients, who notably had a greater duration of septic shock. CONCLUSION: The present study suggests that in humans and in rats, septic shock is associated with decreased ACTH synthesis that is not compensated by its two natural secretagogues, AVP and CRH. One underlying mechanism might be increased expression of iNOS in hypothalamic parvocellular neurons.

Human and experimental septic shock are characterized by depletion of lipid droplets in the adrenals.

RATIONALE: Cholesteryl ester deficiency which results in adrenal lipid store depletion has been proposed as a potential mechanism of sepsis associated adrenal insufficiency. OBJECTIVE: We investigated histological abnormalities associated with sepsis in human and mice adrenals. METHODS: From January 2006 to 2008, seven patients who died of septic shock and seven patients with rapidly fatal nonseptic illness were included. Adrenals were sampled within 12 h from death. Adrenals were also taken from 13 lipopolysaccharide (LPS)-challenged mice, 5 cecal ligation and puncture (CLP) mice and 5 controls. We semi-quantitatively analysed intensity of inflammation, necrosis, haemorrhage and lipid depletion. MEASUREMENTS AND MAIN RESULTS: In patients, lipid depletion scores were significantly higher in septic shock than in controls (p = 0.011). In animals, lipid depletion was higher following LPS or CLP than in controls (p = 0.003). In adrenal cortex, in patients and not in animals, global scores for inflammation (p = 0.002), necrosis (p = 0.009) and haemorrhage (p = 0.009) were significantly higher in septic shock than in controls. Similarly, in zona fasciculata, in patients and not in animals, scores for inflammation (p = 0.007), necrosis (p = 0.023) and haemorrhage (p = 0.023) were significantly higher in septic shock than in controls. CONCLUSIONS: This study shows that diffuse lipid depletion in zona fasciculata is a hallmark of human septic shock, experimental endotoxaemia and sepsis. In patients, sepsis was associated with inflammation, necrosis and haemorrhage predominantly in zona fasciculata.