Deep spatial profiling of human COVID-19 brains reveals neuroinflammation with distinct microanatomical microglia-T-cell interactions.

COVID-19 can cause severe neurological symptoms, but the underlying pathophysiological mechanisms are unclear. Here, we interrogated the brain stems and olfactory bulbs in postmortem patients who had COVID-19 using imaging mass cytometry to understand the local immune response at a spatially resolved, high-dimensional, single-cell level and compared their immune map to non-COVID respiratory failure, multiple sclerosis, and control patients. We observed substantial immune activation in the central nervous system with pronounced neuropathology (astrocytosis, axonal damage, and blood-brain-barrier leakage) and detected viral antigen in ACE2-receptor-positive cells enriched in the vascular compartment. Microglial nodules and the perivascular compartment represented COVID-19-specific, microanatomic-immune niches with context-specific cellular interactions enriched for activated CD8+ T cells. Altered brain T-cell-microglial interactions were linked to clinical measures of systemic inflammation and disturbed hemostasis. This study identifies profound neuroinflammation with activation of innate and adaptive immune cells as correlates of COVID-19 neuropathology, with implications for potential therapeutic strategies.

Intestinal IL-1ß Plays a Role in Protecting against SARS-CoV-2 Infection.

The intestine is constantly balancing the maintenance of a homeostatic microbiome and the protection of the host against pathogens such as viruses. Many cytokines mediate protective inflammatory responses in the intestine, among them IL-1ß. IL-1ß is a proinflammatory cytokine typically activated upon specific danger signals sensed by the inflammasome. SARS-CoV-2 is capable of infecting multiple organs, including the intestinal tract. Severe cases of COVID-19 were shown to be associated with a dysregulated immune response, and blocking of proinflammatory pathways was demonstrated to improve patient survival. Indeed, anakinra, an Ab against the receptor of IL-1ß, has recently been approved to treat patients with severe COVID-19. However, the role of IL-1ß during intestinal SARS-CoV-2 infection has not yet been investigated. Here, we analyzed postmortem intestinal and blood samples from patients who died of COVID-19. We demonstrated that high levels of intestinal IL-1ß were associated with longer survival time and lower intestinal SARS-CoV-2 RNA loads. Concurrently, type I IFN expression positively correlated with IL-1ß levels in the intestine. Using human intestinal organoids, we showed that autocrine IL-1ß sustains RNA expression of IFN type I by the intestinal epithelial layer. These results outline a previously unrecognized key role of intestinal IL-1ß during SARS-CoV-2 infection.

The influence of cooling on biomechanical time since death estimations using ovine brain tissue.

The significance of biomechanical analyses for forensic time since death estimations has recently been demonstrated. Previous biomechanical analyses successfully discriminated post-mortem brain tissue from tissue with a post-mortem interval of at least one day when held at 20 °C. However, the practical utility of such analyses beyond day one at 20 °C was limited. This study investigates the storage, loss, and complex shear modulus of various brain regions in sheep stored at 4 °C in 24-hour intervals over four days post-mortem using rheometry tests. The aim is to identify the critical biomechanical tissue property values to predict post-mortem time and assess the temperature sensitivity of the rheometry method by comparing results to recent findings at 20 °C. Thirty sheep brains were examined, including the frontal lobe, parietal lobe, anterior and posterior deep brain, superior colliculi, pons, medulla, and cerebellum. Rheometry tests were conducted, and receiver operator characteristic analyses were employed to establish cut-off values. At 4 °C storage, all investigated biomechanical properties of the examined brain regions remained stable for at least one day post-mortem. Using cerebellar samples stored at 4 °C, a post-mortem interval of at least two days could be determined with excellent diagnostic ability. Complex shear modulus values below 1435 Pa or storage modulus values below 1313 Pa allowed prediction of two or more days post-mortem. Comparisons between 4 °C and 20 °C revealed brain region-specific results. For instance, the complex shear moduli of the anterior deep brain at 4 °C were significantly higher on all individual testing days when compared to 20 °C. In contrast, the combined medulla and pons samples were similar on each day. Rheometry testing of brain tissue consistently stored at 4 °C since death proved valuable for forensic time since death estimations starting from two days after death.

Concordance between MITS and conventional autopsies for pathological and virological diagnoses.

In pandemics or to further study highly contagious infectious diseases, new strategies are needed for the collection of post-mortem tissue samples to identify the pathogen as well as its morphological impact. In this study, an ultrasound-guided minimally invasive tissue sampling (MITS) protocol was developed and validated for post-mortem use. The histological and microbiological qualities of post-mortem specimens were evaluated and compared between MITS and conventional autopsy (CA) in a series of COVID-19 deaths. Thirty-six ultrasound-guided MITS were performed. In five cases more, specimens for histological and virological examination were also obtained and compared during the subsequently performed CA. Summary statistics and qualitative interpretations (positive, negative) were calculated for each organ tissue sample from MITS and CA, and target genes were determined for both human cell count (beta-globin) and virus (SARS-CoV-2 specific E gene). There are no significant differences between MITS and CA with respect to the detectability of viral load in individual organs, which is why MITS can be of utmost importance and an useful alternative, especially during outbreaks of infectious diseases.

Morphine concentrations in fatalities after palliative treatment of acute burn injury.

The evaluation of a morphine concentration in postmortem blood is routine for a forensic toxicologist. We here report three fatal cases where we found high morphine concentrations with 7.96, 4.30, and 5.82 mg/l in femoral blood that have to be estimated as unusually high. All these individuals died due to severe burn injuries and obtained morphine in the context of their palliative care in the last hours of their lives. According to the autopsy results, the cause of death in case 1 was burn disease with burns of about 90% of the body surface area (BSA), case 2 burn trauma, and case 3 burn shock. Besides morphine, propofol, fentanyl, sufentanil, midazolam, diazepam, lorazepam, cefazolin, and rocuronium were detected in femoral blood. The findings fitted well with the detailed clinical documentation. Further evidence of therapeutic concentrations of quetiapine, duloxetine, and melperone could be matched to preexisting medication of the individuals. Physiologically based pharmacokinetic modelling (PBPK) was applied, developed for the intravenous administration of morphine, to find an explanation for the high morphine concentrations in femoral blood. Quantification of morphine in body fluids and tissue was performed to calculate morphine tissue concentration ratios to the morphine concentration in femoral blood. The presented cases show that pharmacokinetic simulations can reflect decreased renal clearance and decreased hepatic metabolism in general. However, this prediction is not sufficient to explain the high morphine concentrations in femoral blood measured here. It can be assumed that burn shock in particular leads to altered pharmacokinetics, namely decreased distribution of morphine.

Medicolegal Implications of Deaths due to Agricultural Accidents.

ABSTRACT: Agriculture encompasses a variety of activities that carry with them a variety of different risks. The unsafe use of vehicles, machinery, and tools as well as animal husbandry, working at heights, and exposure to chemical, biological, and weather events may result in the deaths of agricultural workers. Inexperienced operators and/or their inappropriate conduct may lead to avoidable fatalities. Forensic pathologists operating with the support of agricultural engineers or other professionals must evaluate the death scene, the case background and circumstances, the autopsy findings, and the toxicological data to establish the factors and dynamics responsible for such accidents and deaths.The aim of this review is to focus on the diagnostic approach required, by means of an interdisciplinary approach, to identify the cause of some typical agricultural fatalities, to confirm that death was accidental, and to help exclude the possibility of homicide or suicide.

New Postmortem Perspective on Emerging SARS-CoV-2 Variants of Concern, Germany.

We performed autopsies on persons in Germany who died from COVID-19 and observed higher nasopharyngeal SARS-CoV-2 viral loads for variants of concern (VOC) compared with non-VOC lineages. Pulmonary inflammation and damage appeared higher in non-VOC than VOC lineages until adjusted for vaccination status, suggesting COVID-19 vaccination may mitigate pulmonary damage.

Microstructural analysis on the innervation of the anterior, medial, and lateral human hip capsule: Preliminary evidence on its neuromechanical contribution.

OBJECTIVE: Capsular repair aims to minimize damage to the hip joint capsular complex (HJCC) and subsequent dislocation risk following total hip arthroplasty (THA). Numerous explanations for its success have been advocated, including neuromuscular feedback loops originating from within the intact HJCC. This research investigates the hypothesis that the HJCC contributes to hip joint stability by analyzing HJCC innervation. METHOD: Twenty-nine samples from the anterior, medial, and lateral aspects of the midportion HJCC of 29 individuals were investigated stereologically and immunohistochemically to identify encapsulated mechanoreceptors according to a modified Freeman and Wyke classification, totaling 11,745 sections. Consecutive slices were observed to determine the nerve course within the HJCC. RESULTS: Few encapsulated mechanoreceptors were found in the HJCC subregions and overlying tissues across the cohort studied. Of regions studied, no significant regional differences in the density of mechanoreceptors were found. No significant difference in mechanoreceptor density was found between sides (left, 10.2×10-4/mm3, 4.0×10-4 - 19.0×10-4/mm3; right 12.9×10-4/mm3, 5.0×10-4 - 22.0×10-4/mm3; mean, 95% confidence intervals) sexes (female 10.4×10-4/mm3, 4.0×10-4 - 18.0×10-4/mm3; male 11.6×10-4/mm3, 5.0×10-4 - 20.0×10-4/mm3; mean, 95% confidence intervals), nor in correlation with age demographics. Myelinated nerves coursed consistently within the HJCC in various orientations. CONCLUSION: Sparse mechanoreceptor density suggests that the HJCC contributes to a limited extent to hip joint stabilization. HJCC nerve terminals may potentially contribute to neuromuscular feedback loops with associated muscles to mediate joint stability in tandem with the active and passive components of the joint.

Vagus nerve inflammation contributes to dysautonomia in COVID-19.

Dysautonomia has substantially impacted acute COVID-19 severity as well as symptom burden after recovery from COVID-19 (long COVID), yet the underlying causes remain unknown. Here, we hypothesized that vagus nerves are affected in COVID-19 which might contribute to autonomic dysfunction. We performed a histopathological characterization of postmortem vagus nerves from COVID-19 patients and controls, and detected SARS-CoV-2 RNA together with inflammatory cell infiltration composed primarily of monocytes. Furthermore, we performed RNA sequencing which revealed a strong inflammatory response of neurons, endothelial cells, and Schwann cells which correlated with SARS-CoV-2 RNA load. Lastly, we screened a clinical cohort of 323 patients to detect a clinical phenotype of vagus nerve affection and found a decreased respiratory rate in non-survivors of critical COVID-19. Our data suggest that SARS-CoV-2 induces vagus nerve inflammation followed by autonomic dysfunction which contributes to critical disease courses and might contribute to dysautonomia observed in long COVID.

Analysis of Three-Dimensional Bone Microarchitecture of the Axis Exposes Pronounced Regional Heterogeneity Associated with Clinical Fracture Patterns.

The odontoid process (dens) of the second cervical vertebra (axis) is prone to fracture. While the importance of its skeletal integrity has been previously noted, representative three-dimensional microarchitecture analyses in humans are not available. This study aimed to determine the bone microarchitecture of the axis using high-resolution quantitative computed tomography (HR-pQCT) and to derive clinical implications for the occurrence and treatment of axis fractures. For initial clinical reference, the apparent density of the axis was determined based on clinical computed tomography (CT) images in patients without and with fractures of the axis. Subsequently, 28 human axes (female 50%) obtained at autopsy were analyzed by HR-pQCT. Analyses were performed in three different regions corresponding to zones I (tip of dens), II (base of dens), and III (corpus axis) of the Anderson and D'Alonzo classification. Lower apparent densities based on clinical CT data were detected in zone II and III compared to zone I in both the group without and with fracture. In the autopsy specimens, cortical thickness and bone volume fraction decreased continuously from zone I to zone III. Trabecular and cortical tissue mineral density was lowest in zone III, with no differences between zones I and II. In conclusion, our clinical and high-resolution ex vivo imaging data highlight a marked regional heterogeneity of bone microarchitecture, with poor cortical and trabecular properties near the dens base. These results may partly explain why zones II and III are at high risk of fracture and osteosynthesis failure.

The use of brain tissue mechanics for time since death estimations.

Time since death estimation is a vital part of forensic pathology. Despite the known tissue degradation after death, the efficacy of using biomechanical tissue properties to estimate time since death remains unexplored. Here, eight brain tissue localizations were sampled from the frontal lobe, parietal lobe, anterior and posterior deep brain, superior colliculi, pons, medulla, and cerebellum of 30 sheep; were then stored at 20 °C; and subsequently subjected to rheometry tests on days zero to four after death. Overall, the measured tissue storage modulus, loss modulus, and complex shear modulus decreased after death for all of the tested regions in a site-specific manner. Day zero to day one changes were the only 24-h interval, for which statistically significant differences in tissue mechanical moduli were observed for some of the tested brain regions. Based on receiver operator characteristic analyses between day zero and the pooled data of days one to four, a post mortem interval of at least 1 day can be determined with a sensitivity of 90%, a specificity of 92%, and a positive likelihood ratio of 10.8 using a complex shear modulus cut-off value of 1461 Pa for cerebellar samples. In summary, biomechanical properties of brain tissue can discriminate between fresh and at least 1-day-old samples stored at 20 °C with high diagnostic accuracy. This supports the possible value of biomechanical analyses for forensic time since death estimations. A striking advantage over established methods to estimate the time since death is its usability in cases of disintegrated bodies, e.g. when just the head is found.

Heart weight must not be measured before dissection during autopsies.

During autopsies, weighing the heart is a standard procedure. In addition to myocardial pathologies, heart size, and ventricular wall thickness, heart weight is a common parameter to describe cardiac pathology and should be recorded as accurately as possible. To date, there exists no standard for recording heart weight at autopsy, although some authors recommend weighing the heart after dissection and removal of blood and blood clots. In the study presented, the hearts of 58 decedents were weighed after being dissected out of the pericardial sac (a), after dissection using the short-axis or inflow-outflow method with manual removal of blood and blood clots (b), and after rinsing and drying (c). Depending on the dissection method, the heart weight was 7.8% lower for the inflow-outflow method and 11.6% lower for the short-axis method after dissection compared to before and correspondingly 2.9% to 5% lower again after rinsing and drying respectively. Accordingly, the heart should be dissected, blood and blood clots removed, rinsed with water, and dried with a surgical towel after dissection, before weighing.

Adventure Legal Medicine: a free online serious game for supplementary use in undergraduate medical education.

Serious games (computer-based learning games) are increasingly used in medical education at various levels, as user access is independent of location and time and promotes non-linear learning. In legal medicine, interactive digital media are still scarce. The freely accessible online serious game "Adventure Legal Medicine" was developed as part of the "Hamburg Open Online University". The goal was to teach the basics of forensic casework in a point-and-click adventure setting consisting of five cases. During development, 40 medical students were asked to evaluate the game anonymously. The System Usability Scale (SUS) resulted in a mean score of 86.7 (SD 8.3), which corresponds to above-average usability. Further specific evaluations revealed a good to very good rating of the game with no differences in terms of gender (p = 0.214), first-year versus advanced students (p = 0.393) and students who never/rarely or sometimes/often played computer games (p = 0.780). Since there are only a few digital media so far that allow curricular integration into undergraduate teaching in legal medicine, this serious game represents a possibility to integrate digital media into both face-to-face teaching and distance learning and to use it as a supplement to the medical school's own teaching offer, encouraging users to actively engage with the subject.

Seroprevalence of arthropod-borne bacterial infections in homeless individuals in Hamburg in 2020.

PURPOSE: The number of homeless people in Germany is steadily increasing. Due to their often precarious living conditions, this specific population may be increasingly exposed to ectoparasites that can transmit various pathogens. To assess the prevalence and thus the risk of such infections, we analyzed the seropositivity of rickettsiosis, Q fever, tularemia and bartonellosis in homeless individuals. METHODS: A total of 147 homeless adults from nine shelters in Hamburg, Germany, were included. The individuals underwent questionnaire-based interviewing, physical examination, and venous blood was drawn between May and June 2020. Blood samples were analyzed for antibodies against rickettsiae (Rickettsia typhi and R. conorii), Coxiella burnetii, Francisella tularensis and bartonellae. RESULTS AND CONCLUSION: A very low seroprevalence of R. typhi and F. tularensis infection was found (0-1%), while antibodies against R. conorii and C. burnetii were more common (7% each), followed by a relatively high seroprevalence of 14% for bartonellosis. Q fever seroprevalence was associated with the country of origin, whereas bartonellosis seroprevalence was associated with the duration of homelessness. Preventive measures targeting ectoparasites, especially body lice, should be put in place continuously.

Determinants of health-related quality of life (HRQoL) among homeless individuals during the COVID-19 pandemic.

OBJECTIVE: Thus far, there is very limited knowledge regarding homeless individuals during the COVID-19 pandemic, particularly related to the health-related quality of life (HRQoL). Thus, our aim was to evaluate HRQoL and to clarify the determinants of HRQoL among homeless individuals during the COVID-19 pandemic in Germany. METHODS: Data were taken from the national survey on psychiatric and somatic health of homeless individuals during the COVID-19 pandemic-NAPSHI (n = 616). The established EQ-5D-5L was used to quantify problems in five health dimensions, and its visual analogue scale (EQ-VAS) was used to record self-rated health status. Sociodemographic factors were included in regression analysis. RESULTS: Pain/discomfort was the most frequently reported problem (45.3%), thereafter anxiety/depression (35.9%), mobility (25.4%), usual activities (18.5%) and self-care (11.4%). Average EQ-VAS score was 68.97 (SD: 23.83), and the mean EQ-5D-5L index was 0.85 (SD: 0.24). Regressions showed that higher age and having a health insurance were associated with several problem dimensions. Being married was associated with higher EQ-VAS scores. CONCLUSIONS: Overall, our study findings showed a quite high HRQoL among homeless individuals during the COVID-19 pandemic in Germany. Some important determinants of HRQoL were identified (e.g., age or marital status). Longitudinal studies are required to confirm our findings.

Binucleated Myocytes and Heart Weight: A Preliminary Study Linking Cardiac Hypertrophy and Myocyte Hypertrophy.

ABSTRACT: Hypertrophy of the heart is assessed by heart weight (and dimensions) and myocyte hypertrophy. Establishing an association between the two may be useful in assessing hypertrophy in cases where there are limitations in assessing the heart weight. This preliminary study explored the association between the number of binucleated myocytes (a feature of myocyte hypertrophy) in a randomly chosen single high-power field of the left ventricular free wall and heart weight in an adult White population. It also compared the number of binucleated myocytes between cases with increased heart weight (>400 g in female and >500 g in male) and cases with normal heart weight. Heart weight and number of binucleated myocytes correlated significantly in male only. Increased heart weight had a significantly higher number of binucleated myocytes, with 8.5 binucleated myocytes being able to segregate cases with increased heart weight (74% sensitivity and 79% specificity). The results of this study showed the number of binucleated myocytes may have a complementary role in assessing hypertrophy of the heart.

Gross Heart Dimensions From Postmortem Computed Tomography and Postmortem Examination Measurements: Heart Weight and Cardiac Hypertrophy.

ABSTRACT: An increased heart weight (cardiac hypertrophy) is associated with underlying heart disease and sudden cardiac death. Gross heart dimensions can be used to estimate heart weight as a surrogate for cardiac hypertrophy. These dimensions can be obtained from either postmortem computed tomography or postmortem examination. This study compared the gross heart dimensions, heart weight estimations, and ability to determine cardiac hypertrophy (>400 and >500 g) between these 2 methods. The results showed that gross dimensions from postmortem computed tomography were significantly smaller and overall had less accuracy in estimating heart weight than dissection. In terms of cardiac hypertrophy, both methods were comparable and had reasonably high sensitivity and specificity, albeit having slightly varied characteristics, to determine whether the heart showed hypertrophy.

[Information on Death Certificates: Comparison Between Inpatient and Outpatient Sectors]. / Angaben auf Todesbescheinigungen ­ Vergleich des hospitalen und ambulanten Bereichs.

The death of a person and the circumstances of death are documented on the death certificate in Germany. The path of the corpse to burial as well as the quality of the cause of death statistics are significantly influenced by the information in the official death certificate. The quality of the information in the death certificates has been repeatedly criticized. The aim of the present study was to identify typical sources of error in death certificates and to obtain information on whether qualitative differences exist between death certificates completed in the outpatient and inpatient sectors. A retrospective evaluation was performed of 218 death certificates of deaths examined by the Institute of Legal Medicine as part of a second postmortem examination prior to cremation. Of these, 118 death certificates were issued in the hospital and 100 death certificates were issued on an outpatient basis by the family physician or a physician on duty in the outpatient sector. All but one of the death certificates issued on an outpatient basis were legible. The information on the underlying disease was plausible. More than one-third of the epicrises had no significant findings or were not completed at all. The entry on the immediate causes of death in the designated field on the death certificate (Ia in the causal chain) were inadequate in one third of the cases. The error rate in the entries was higher in outpatient than in inpatient deaths. In the future, therefore, it will be necessary to prepare for the special situation of a post-mortem examination by means of further and advanced training events and to convey the importance of the diagnoses determined in the process, in order to eliminate these avoidable sources of error.

Full endoscopic anterior intrapelvic plate osteosynthesis: a cadaveric feasibility study.

In this investigation, it was assumed that it must be possible to visualize the intrapelvic aspect as accustomed by pelvic surgeons using the anterior intrapelvic (modified Stoppa) approach. Moreover, it was hypothesized, that plate mountings will not only be possible for the symphysis but also at the supra- and infrapectineal aspect as well as to the posterior column. Ten anonymized cadaveric specimens were included in this study. A standard laparoscopic totally extraperitoneal (TEP) approach was used. A total of 10 landmarks were defined that are usually within reach in the open anterior intrapelvic (AIP) approach. Moreover, five different plate mountings were tested. The locations were chosen in accordance with the indication spectrum suitable for open surgery through the traditional AIP approach. It was possible to gain intrapelvic visibility in seven of ten cases. In all of those seven cases, it was technically possible to place plates to the symphysis, superior pubic ramus, as well as longer anterior column plates up to the aspect posterior of the acetabulum. In the last four of the seven cases, it was possible to mount plates to the infrapectineal aspect as well as the posterior column, too. The team, previously trained in arthroscopic surgical techniques as well as pelvic trauma surgery, observed a steep learning curve. This investigation demonstrated, that endoscopic anterior intrapelvic plate osteosynthesis was feasible in the majority of the cases in a series of ten cadaveric models. New instruments will be needed such as extra-long rasp elevators, ball-spikes as well as devices to hold and position plates and extra-long self-holding screwdrivers. With these, endoscopic pelvic surgery will likely be a realistic option for selected pelvic trauma cases in the future.

[Health of homeless individuals during the COVID-19 pandemic]. / Gesundheit wohnungsloser Menschen während der COVID-19-Pandemie.

The living situation and health of homeless people differs from the general population in many ways. It is reasonable to assume that the homeless population has been particularly vulnerable during the coronavirus disease 2019 (COVID-19) pandemic. This narrative review will summarize the current literature on the health and care of homeless people during the COVID-19 pandemic. The literature research was performed between December 2022 and February 2023. In addition to the current national and international literature, findings from the "National Survey on the Psychiatric and Somatic Health of Homeless Individuals" (NAPSHI study) will be synopsized, examining psychiatric and somatic diseases as well as the care for homeless people in Germany.Homeless individuals are often mentally and physically ill and have limited access to the regular medical care system. Facilities with group rooms and dormitories pose a risk for outbreaks during the COVID-19 pandemic. As suspected, evidence of Severe Acute Respiratory Syndrome Coronavirus Type 2 (SARS-CoV­2) infections emerged more frequently in homeless individuals than in the general population during the pandemic. Many of the infected individuals were asymptomatic. High rates of those unknowingly infected homeless individuals may have contributed to the spread of the viral disease. However, uncontrolled COVID-19 outbreaks, as feared by some researchers at the beginning of the pandemic, were not observed.