Lateral flow devices for samples collected by straw sampling method for postmortem canine rabies diagnosis.

The direct fluorescent antibody test (dFAT) using brain sample after opening the skull is the standard rabies diagnostic test in animal rabies. However, it is not feasible in many resource-limited settings. Lateral flow devices (LFD) combined with a simple sampling methodology is quicker, simpler, and less hazardous than the standard test and can be a useful tool. We conducted a prospective on-site study to evaluate the diagnostic accuracy of the LFD with the straw sampling method compared with that of the dFAT with the skull opening procedure for post-mortem canine rabies diagnosis. We collected 97 rabies-suspected animals between December 1, 2020 and March 31, 2021. Among the 97 samples, 53 and 50 cases were positive tests for dFAT and LFD, respectively. The sensitivity and specificity of LFD with straw sampling method were 94.3% (95% confidence interval [CI], 84.3-98.8%) and 100% (95% CI, 92.0-100%), respectively. The performance of LFD by the straw sampling method showed relatively high sensitivity and 100% specificity compared with that of dFAT performed on samples collected after opening the skull. This methodology can be beneficial and is a strong tool to overcome limited animal surveillance in remote areas. However, because of our limited sample size, more data using fresh samples on-site and the optimizations are urgently needed for the further implementation in endemic areas.

Pictorial review of the postmortem computed tomography in neonaticide cases.

Neonaticide is defined by the deliberate killing or homicide of a child within 24 h of its birth. In this context, three fundamental questions are generally asked of the forensic pathologist: what is the cause of death of the neonate? Was the child viable (i.e., what is the gestational age of the neonate)? Finally, was the neonate stillborn or liveborn?Postmortem imaging can help answer these questions by conducting (1) a complete lesional analysis of the body and the placenta, (2) an estimation of the gestational age by measuring the lengths of the diaphyseal long bones, and (3) an analysis of the aeration of the lungs and intestines. Using the details of 18 cases, we illustrate aspects of neonaticide cases in postmortem computed tomography (PMCT), offering detailed examples of notable postmortem changes and abnormalities, especially in the analysis of the pulmonary parenchyma. This article presents a useful iconography for the radiologist confronted with this rare yet complex forensic situation.

Dedicated container for postmortem human brain ultra-high field magnetic resonance imaging.

BACKGROUND: The emerging field of ultra-high field MRI (UHF-MRI, 7 Tesla and higher) provides the opportunity to image human brains at a higher resolution and with higher signal-to-noise ratios compared to the more widely available 1.5 and 3T scanners. Scanning postmortem tissue additionally allows for greatly increased scan times and fewer movement issues leading to improvements in image quality. However, typical postmortem neuroimaging routines involve placing the tissue within plastic bags that leave room for susceptibility artifacts from tissue-air interfaces, inadequate submersion, and leakage issues. To address these challenges in postmortem imaging, a custom-built nonferromagnetic container was developed that allows whole brain hemispheres to be scanned at sub-millimeter resolution within typical head-coils. METHOD: The custom-built polymethylmethacrylaat container consists of a cylinder with a hemispheric side and a lid with valves on the adjacent side. This shape fits within common MR head-coils and allows whole hemispheres to be submerged and vacuum sealed within it reducing imaging artifacts that would otherwise arise at air-tissue boundaries. Two hemisphere samples were scanned on a Siemens 9.4T Magnetom MRI scanner. High resolution T2* weighted data was obtained with a custom 3D gradient echo (GRE) sequence and diffusion-weighted imaging (DWI) scans were obtained with a 3D kT-dSTEAM sequence along 48 directions. RESULTS: The custom-built container proved to submerge and contain tissue samples effectively and showed no interferences with MR scanning acquisition. The 3D GRE sequence provided high resolution isotropic T2* weighted data at 250 µm which showed a clear visualization of gray and white matter structures. DWI scans allowed for dense reconstruction of structural white matter connections via tractography. CONCLUSION: Using this custom-built container worked towards achieving high quality MR images of postmortem brain material. This procedure can have advantages over traditional schemes including utilization of a standardized protocol and the reduced likelihood of leakage. This methodology could be adjusted and used to improve typical postmortem imaging routines.

Postmortem Computed Tomography Angiography of Newborns.

We propose an original method of postmortem computed tomography angiography of the body of a deceased newborn. The work is based on the analysis of the results of comprehensive postmortem computed tomography and pathological examination of 30 newborns, who died from congenital malformations. The key to a full-fledged postmortem radiation study using intravascular contrasting of deceased newborns and infants is the presence of vascular catheters established during life, as well as conducting it no earlier than 12 h and no later than 48 h after death. As a contrast agent, we recommend to use an iodine-containing water-soluble radiopaque drug containing at least 250 mg of iodine per 1 ml. The volume of contrast agent is calculated based on body weight, taking into account the general edema syndrome. The introduction of a contrast agent is carried out through vascular catheters in 3 stages in various positions of the body. The analysis of tomograms and 3D-reconstruction of blood vessels using their pseudocoloring allows accurate assessment of the topography of blood vessels with the possibility of separate study of the arterial and venous vessels, and to identify both congenital abnormalities of the heart and blood vessels, and their acquired pathology. CT angiography in some cases is superior to traditional autopsy in the diagnosis of blood vessel pathology. Postmortem CT angiography should be considered as an important stage of postmortem radiology in the structure of comprehensive pathological analysis of newborns and infants.

Feasibility of postmortem examination in the era of COVID-19 pandemic: the experience of a Northeast Italy University Hospital.

With the continuous spreading of SARS-CoV-2 and increasing number of deaths worldwide, the need and appropriateness for autopsy in patients with COVID-19 became a matter of discussion. In fact, in the COVID-19 era protection of healthcare workers is a priority besides patient management. No evidence is currently available about the real risk related to the procedure as well as to the subsequent management of the samples. We herein describe the procedure that has been used to perform the first series of postmortem examinations in the COVID center of the Padua University Hospital, Padua, Italy, after the implementation of an ad hoc operating procedure, to minimize the risk of infection for pathologists and technicians. Provided that the procedure is performed in an adequate environment respecting strict biosafety rules, our data indicate that complete postmortem examination appears to be safe and will be highly informative providing useful insights into the complex disease pathogenesis.

Cutaneous wound metallic residues pattern analysis with SEM-EDX in a forensic case of overkill.

The term overkill identifies the infliction of massive injuries that greatly exceed those needed to kill the victim both in number and intensity. We present the case of a Peruvian transsexual, who was choked and hit by 11 sharp-force wounds all in the facial area. The scanning electron microscopy with energy dispersion X-ray analysis carried out on the skin of the facial wounds proved crucial in proving that two different point-and-edge weapons were used, following the finding of metallic micro-traces of heterogeneous composition. This discovery and the autopsy highlighted the use of two distinct types of injury (mechanical asphyxia and sharp-force trauma) showed that this murder amounted to overkill.

COVID-19 Autopsies, Oklahoma, USA.

OBJECTIVES: To report the methods and findings of two complete autopsies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive individuals who died in Oklahoma (United States) in March 2020. METHODS: Complete postmortem examinations were performed according to standard procedures in a negative-pressure autopsy suite/isolation room using personal protective equipment, including N95 masks, eye protection, and gowns. The diagnosis of coronavirus disease 2019 (COVID-19) was confirmed by real-time reverse transcriptase polymerase chain reaction testing on postmortem swabs. RESULTS: A 77-year-old obese man with a history of hypertension, splenectomy, and 6 days of fever and chills died while being transported for medical care. He tested positive for SARS-CoV-2 on postmortem nasopharyngeal and lung parenchymal swabs. Autopsy revealed diffuse alveolar damage and chronic inflammation and edema in the bronchial mucosa. A 42-year-old obese man with a history of myotonic dystrophy developed abdominal pain followed by fever, shortness of breath, and cough. Postmortem nasopharyngeal swab was positive for SARS-CoV-2; lung parenchymal swabs were negative. Autopsy showed acute bronchopneumonia with evidence of aspiration. Neither autopsy revealed viral inclusions, mucus plugging in airways, eosinophils, or myocarditis. CONCLUSIONS: SARS-CoV-2 testing can be performed at autopsy. Autopsy findings such as diffuse alveolar damage and airway inflammation reflect true virus-related pathology; other findings represent superimposed or unrelated processes.

The use of scanning electron microscopy and energy dispersive X-ray spectroscopy in a case of occupational death.

Scanning electron microscopy is a technique that provides high-resolution images at the micro- and nano-scale. The combination of scanning electron microscopy and energy dispersive X-ray spectroscopy analysis is developing fast for application in forensic science. In this work, we report a case of work-related traumatic death of a 50-year-old man. The autopsy showed cranial fractures with cerebral haemorrhage. It was more difficult to understand the accident dynamics because the body had been shifted from the accident site to mask what had really taken place. Scanning electron microscopy/energy dispersive X-ray spectroscopy was used to identify the material of the impacting tool and to establish the possible legal responsibility of the employer. In this study, we demonstrate that scanning electron microscopy/energy dispersive X-ray spectroscopy is a useful forensic tool for the analysis of biological samples. Further, for studying the lacerations on the corpse from doubtful blunt tools, scanning electron microscopy/energy dispersive X-ray spectroscopy can assist in demonstrating that the scene has been falsified, as it was in this case.

Analysis of false start bone lesions produced by an electrical oscillating autopsy saw.

Postmortem dismemberment results from the use of sharp or sharp blunt instruments. Saws produce specific bone lesions, and the observation of certain saw mark features allows for the recognition of certain characteristics of the saw and its teeth. At autopsy, sections of the skull and other parts of the skeleton are usually achieved using an electrical oscillating autopsy saw. In cases of dismemberment, this autopsy saw may create additional marks to those produced by the criminal activity. In order to help the forensic pathologist to differentiate the two types of marks, this experimental study used a stereomicroscope to examine 130 experimental false starts produced on animal and human bones by an oscillating autopsy saw. A flagrant succession of narrow and wide aspects of the walls (in a "figure of 8" shape), with obvious oval bone islands and undulating striae are patterns typically left behind by oscillating autopsy saws, but the depth of the false starts plays an important role in the variation of the features. In particular, superficial false starts tend to be associated with larger kerf widths, straight walls, and longitudinal bone islands.

Contamination Is Not Linked to the Gestational Microbiome.

Differentiating between contamination and the genuine presence of 16S rRNA genes in gestational tissue samples is the gold standard for supporting the in utero colonization hypothesis. During gestation, the fetus undergoes significant physiological changes that may be directly affected by maternal colonization of key bacterial genera. In this study, lab benches, necropsy tables, and air ducts were swabbed at the same time as clinical sampling. The relative and absolute abundance of bacteria present in sheep samples was determined by culture-independent and culture-dependent means. Of 14 healthy pregnant ewes, there was no evidence of any bacteria in the fetal liver, spleen, or brain cortex using culture-independent techniques despite evidence of the presence of bacteria in various locations of the necropsy room used for 11 of these 14 sheep. Of the 336 bacterial genera found in the room swabs, only 12 (5%) were also found in the saliva and vaginal swabs among the three ewes for which bacteria were detected. These 12 taxa represent 1.32% of the relative abundance and approximately 393 16S rRNA copies/swab in these three ewes. Using careful necropsy protocols, bacterial contamination of sheep tissues was avoided. Contamination of saliva and vaginal samples was limited to less than 2% of the bacterial population.IMPORTANCE Recent evidence for a gestational microbiome suggests that active transfer between mother and fetus in utero is possible, and, therefore, actions must be taken to clarify the presence versus absence of these organisms in their respected sources. The value of this study is the differentiation between bacterial DNA identified in the necropsy rooms of animals and bacterial DNA whose origin is purely clinical in nature. We do not know the extent to which microorganisms traverse maternal tissues and infiltrate fetal circulation, so measures taken to control for contamination during sample processing are vital for addressing these concerns.

Perforation rates in double latex gloves and protective effects of outer work gloves in a postmortem examination room: A STROBE-compliant study.

Medical staff face the risk of exposure to blood-borne infectious agents during postmortem examinations. This study investigated the effectiveness of non-slip work gloves worn over 2 layers of surgical latex gloves (outer and inner gloves) as a means of reducing hand and finger injuries. Complete sets of outer and inner gloves worn during postmortem examinations were collected from participating forensic staff. Latex gloves were categorized into 2 groups based on the users' actions during the examination: the wearing group if the wearer wore their work gloves continuously without interruption, and the taking-off group if the wearer removed them at least once. Perforation rates, locations, and shapes were compared between these groups. Outer-glove perforation occurred significantly more often in the taking-off group (n = 102 pairs) than in the wearing group (n = 91 pairs) (30.4% vs 3.8%, P < .001). Inner-glove perforation occurred at rates of 2.0% and 0.5% (P = .38), respectively. The wearers did not incur hand or finger injuries. Perforation rates were similar between the dominant and non-dominant hands (P = .18). Regarding location, gloves were punctured most frequently at the thumb, followed by the index finger. Most examiners (85.6%) did not notice the perforation when the damage occurred. Therefore, we could not confirm that a specific operation within a set of plural operations affected the rate of perforation. Additionally, we could not prove a relationship between glove perforation and each operation performed with/without work gloves. The perforation appearances varied greatly in shape and size, suggesting multiple causes of perforation. The continuous (i.e., uninterrupted) wear of work gloves during postmortem examinations reduced the incidence of perforations in both latex glove layers and thus reduced the risk of hand and finger injury.

Revealing Adenosine A2A-Dopamine D2 Receptor Heteromers in Parkinson's Disease Post-Mortem Brain through a New AlphaScreen-Based Assay.

Background: Several biophysical techniques have been successfully implemented to detect G protein-coupled receptors (GPCRs) heteromerization. Although these approaches have made it possible to ascertain the presence of GPCR heteromers in animal models of disease, no success has been accomplished in pathological human post-mortem brains. The AlphaScreen technology has been consistently used to quantify small analyte accumulation or depletion, bimolecular interactions, and post-translational modifications. The high signal-to-background, dynamic range and sensitivity exhibited by this technology support that it may be suitable to detect GPCR heteromers even under non-optimal conditions. Methods: Here, we describe the development of a new AlphaScreen assay to detect GPCR oligomers in human post-mortem brain. Results: Adenosine A2A-dopamine D2 receptor (A2AR/D2R) heteromer formation was monitored in caudate from healthy and Parkinson's disease (PD) subjects. The approach was first validated using striatal membranes from wild type and A2AR deficient mice. Secondly, we took advantage of the 6-hydroxydopamine hemiparkinsonian rat model to validate previous results. In addition, finally, A2AR/D2R heteromer formation was assessed in caudate membranes from human post-mortem brains. Importantly, our preliminary results revealed an increase in A2AR/D2R heteromer formation in PD brains. Conclusions: The new AlphaScreen assay allowed assessing GPCR heteromers in human post-mortem brains with high sensitivity.

7T MRI allows detection of disturbed cortical lamination of the medial temporal lobe in patients with Alzheimer's disease.

Using 7T T2⁎-weighted imaging, we scanned post-mortem hemispheres of Alzheimer patients and age-matched controls to describe the patterns of appearance of cortical lamination on T2*-weighted MRI in the medial temporal lobe and to assess the changes in Alzheimer patients versus controls. While controls showed a hypointense line of Baillarger in the majority of the cases, appearance of cortical lamination varied to a greater extent in the Alzheimer patients. Severely distorted cortical lamination was also observed in advanced stage Alzheimer patients and presented itself as a broad hypointense inhomogeneous band, covering a large part of the cortical width. Histology indicated that the changes in the appearance of visible cortical lamination were not only associated with myelin changes, but also with diffuse cortical iron alterations and depositions. Therefore, imaging cortical lamination alterations in Alzheimer patients using T2*-weighted MRI might provide new information on involved neuroanatomical structures in an advanced neurodegenerative stage.

The choice of embedding media affects image quality, tissue R2* , and susceptibility behaviors in post-mortem brain MR microscopy at 7.0T.

PURPOSE: The quality and precision of post-mortem MRI microscopy may vary depending on the embedding medium used. To investigate this, our study evaluated the impact of 5 widely used media on: (1) image quality, (2) contrast of high spatial resolution gradient-echo (T1 and T2* -weighted) MR images, (3) effective transverse relaxation rate (R2* ), and (4) quantitative susceptibility measurements (QSM) of post-mortem brain specimens. METHODS: Five formaldehyde-fixed brain slices were scanned using 7.0T MRI in: (1) formaldehyde solution (formalin), (2) phosphate-buffered saline (PBS), (3) deuterium oxide (D2 O), (4) perfluoropolyether (Galden), and (5) agarose gel. SNR and contrast-to-noise ratii (SNR/CNR) were calculated for cortex/white matter (WM) and basal ganglia/WM regions. In addition, median R2* and QSM values were extracted from caudate nucleus, putamen, globus pallidus, WM, and cortical regions. RESULTS: PBS, Galden, and agarose returned higher SNR/CNR compared to formalin and D2 O. Formalin fixation, and its use as embedding medium for scanning, increased tissue R2* . Imaging with agarose, D2 O, and Galden returned lower R2* values than PBS (and formalin). No major QSM offsets were observed, although spatial variance was increased (with respect to R2* behaviors) for formalin and agarose. CONCLUSIONS: Embedding media affect gradient-echo image quality, R2* , and QSM in differing ways. In this study, PBS embedding was identified as the most stable experimental setup, although by a small margin. Agarose and Galden were preferred to formalin or D2 O embedding. Formalin significantly increased R2* causing noisier data and increased QSM variance.

Post mortem high resolution diffusion MRI for large specimen imaging at 11.7 T with 3D segmented echo-planar imaging.

BACKGROUND: Diffusion weighted imaging (DWI) is the only in vivo technique allowing for the mapping of tissue fiber architecture. Post mortem DWI is an increasingly popular method, since longer acquisition times (compared to in vivo) allow higher spatial and angular resolutions to be achieved. However, DWI protocols must be adapted to post mortem tissue (e.g., tuning acquisition parameters to account for changes in T1/T2). New method: In this work, we developed a framework to obtain high quality diffusion weighted images on post mortem large samples by using a combination of fast imaging with 3D diffusion-weighted segmented EPI (3D-DW seg-EPI), Gadolinium soaking and data denoising. Analyses including tractography were used to check the quality of the acquired data, including a comparison with 3D-DW SE acquisitions. Comparison with existing method: Effects on diffusion data of each of the components of the framework were tested: 3D-DW seg-EPI versus 3D-DW SE EPI; with and without data denoising; with and without Gd-soaking. CONCLUSIONS: Our study demonstrated the feasibility of analysing anatomical connectivity using diffusion imaging of a post mortem macaque brain with a 3D-DW seg-EPI sequence acquired at ultra-high field. The combination of high angular and spatial resolution DWI with Gd-soaking and denoising provided data allowing us to perform diffusion tractography with results very similar to those obtained with a 3D-DW SE acquisition (with shorter acquisition times: 222 h versus 37 h for 3D-DW seg-EPI).

Minimally invasive fetal autopsy using ultrasound: a feasibility study.

OBJECTIVES: To evaluate postmortem ultrasound (PM-US) for minimally invasive autopsy, and to demonstrate its feasibility, sensitivity and specificity, as compared with conventional autopsy, in detecting major congenital abnormalities. METHODS: Over a 19-month study period from 1 March 2012 to 30 September 2013, we recruited from a referral hospital 88 consecutive fetuses, at 11-40 weeks' gestation, which had undergone termination, miscarriage or intrauterine fetal death. We performed PM-US using different transducers and compared the data with those from conventional autopsy. The latter was performed, according to the Societé Francaise de Foetopathologie (France) guidelines, by experienced perinatal pathologists who were blinded to the ultrasound data. RESULTS: Complete virtual autopsy by ultrasound was possible in 95.5% of the cases. The sensitivity of PM-US for detecting brain abnormalities was 90.9% (95% CI, 58.7-99.8%) and the specificity was 87.3% (95% CI, 75.5-94.7%). In 20% of cases, a neuropathological examination was not possible due to severe maceration. The sensitivity for detection of thoracic abnormalities was 88.9% (95% CI, 65.3-98.6%) and the specificity was 92.8% (95% CI, 84.1-97.6%), and the sensitivity for detection of abdominal anomalies was 85.7% (95% CI, 57.2-98.2%) and the specificity was 94.6% (95% CI, 86.7-98.5%). CONCLUSION: This pilot study confirms the feasibility of PM-US for virtual autopsy as early as 11 weeks' gestation. This new technique shows high sensitivity and specificity in detecting congenital structural abnormalities as compared with conventional autopsy. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

A systematic review and synthesis of the strengths and limitations of measuring malaria mortality through verbal autopsy.

BACKGROUND: Lack of valid and reliable data on malaria deaths continues to be a problem that plagues the global health community. To address this gap, the verbal autopsy (VA) method was developed to ascertain cause of death at the population level. Despite the adoption and wide use of VA, there are many recognized limitations of VA tools and methods, especially for measuring malaria mortality. This study synthesizes the strengths and limitations of existing VA tools and methods for measuring malaria mortality (MM) in low- and middle-income countries through a systematic literature review. METHODS: The authors searched PubMed, Cochrane Library, Popline, WHOLIS, Google Scholar, and INDEPTH Network Health and Demographic Surveillance System sites' websites from 1 January 1990 to 15 January 2016 for articles and reports on MM measurement through VA. INCLUSION CRITERIA: article presented results from a VA study where malaria was a cause of death; article discussed limitations/challenges related to measurement of MM through VA. Two authors independently searched the databases and websites and conducted a synthesis of articles using a standard matrix. RESULTS: The authors identified 828 publications; 88 were included in the final review. Most publications were VA studies; others were systematic reviews discussing VA tools or methods; editorials or commentaries; and studies using VA data to develop MM estimates. The main limitation were low sensitivity and specificity of VA tools for measuring MM. Other limitations included lack of standardized VA tools and methods, lack of a 'true' gold standard to assess accuracy of VA malaria mortality. CONCLUSIONS: Existing VA tools and methods for measuring MM have limitations. Given the need for data to measure progress toward the World Health Organization's Global Technical Strategy for Malaria 2016-2030 goals, the malaria community should define strategies for improving MM estimates, including exploring whether VA tools and methods could be further improved. Longer term strategies should focus on improving countries' vital registration systems for more robust and timely cause of death data.

Validity of a minimally invasive autopsy for cause of death determination in stillborn babies and neonates in Mozambique: An observational study.

BACKGROUND: Over 5 million stillbirths and neonatal deaths occur annually. Limited and imprecise information on the cause of these deaths hampers progress in achieving global health targets. Complete diagnostic autopsies (CDAs)-the gold standard for cause of death determination-are difficult to perform in most high-burden settings. Therefore, validation of simpler and more feasible methods is needed. METHODS AND FINDINGS: In this observational study, the validity of a minimally invasive autopsy (MIA) method in determining the cause of death was assessed in 18 stillbirths and 41 neonatal deaths by comparing the results of the MIA with those of the CDA. Concordance between the categories of diseases obtained by the 2 methods was assessed by the Kappa statistic, and the sensitivity, specificity, positive, and negative predictive values of the MIA diagnoses were calculated. A cause of death was identified in 16/18 (89%) and 15/18 (83%) stillborn babies in the CDA and the MIA, respectively. Fetal growth restriction accounted for 39%, infectious diseases for 22%, intrapartum hypoxia for 17%, and intrauterine hypoxia for 11% of stillborn babies. Overall, the MIA showed in this group a substantial concordance with the CDA (Kappa = 0.78, 95% CI [0.56-0.99]). A cause of death was identified in all (100%) and 35/41 (85%) neonatal deaths in the CDA and the MIA, respectively. In this group, the majority of deaths were due to infectious diseases (66%). The overall concordance of the MIA with the CDA in neonates was moderate (Kappa = 0.40, 95% CI [0.18-0.63]). A high percentage of accuracy was observed for the MIA in all the diagnostic categories in both stillbirths and neonates (>75%). The main limitation of this study is that some degree of subjective interpretation is inherent to cause-of-death attribution in both the MIA and the CDA; this is especially so in stillbirths and in relation to fetal growth restriction. CONCLUSIONS: The MIA could be a useful tool for cause-of-death determination in stillbirths and neonatal deaths. These findings may help to accelerate progress towards meeting global health targets by obtaining more accurate information on the causes of death in these age groups, which is essential in guiding the design of new interventions and increasing the effectiveness of those already implemented.