B cells orchestrate tolerance to the neuromyelitis optica autoantigen AQP4

Neuromyelitis optica is a paradigmatic autoimmune disease of the central nervous system, in which the water-channel protein AQP4 is the target antigen1. The immunopathology in neuromyelitis optica is largely driven by autoantibodies to AQP42. However, the T cell response that is required for the generation of these anti-AQP4 antibodies is not well understood. Here we show that B cells endogenously express AQP4 in response to activation with anti-CD40 and IL-21 and are able to present their endogenous AQP4 to T cells with an AQP4-specific T cell receptor (TCR). A population of thymic B cells emulates a CD40-stimulated B cell transcriptome, including AQP4 (in mice and humans), and efficiently purges the thymic TCR repertoire of AQP4-reactive clones. Genetic ablation of Aqp4 in B cells rescues AQP4-specific TCRs despite sufficient expression of AQP4 in medullary thymic epithelial cells, and B-cell-conditional AQP4-deficient mice are fully competent to raise AQP4-specific antibodies in productive germinal-centre responses. Thus, the negative selection of AQP4-specific thymocytes is dependent on the expression and presentation of AQP4 by thymic B cells. As AQP4 is expressed in B cells in a CD40-dependent (but not AIRE-dependent) manner, we propose that thymic B cells might tolerize against a group of germinal-centre-associated antigens, including disease-relevant autoantigens such as AQP4.

Fatal intoxication with 1,4-butanediol: Case report and comprehensive review of the literature

A fatal case of 1,4-butanediol (1,4-BD) oral ingestion is reported here, in which a 51-year-old man was found dead in his bed. According to the police report, the deceased was a known drug user. A glass bottle labeled (and later confirmed to be) "Butandiol 1,4" (1,4-BD) was found in the kitchen. Furthermore, the deceased's friend stated that he consumed 1,4-BD on a regular basis. The autopsy and histological examination of postmortem parenchymatous organ specimens did not revealed a clear cause of death. Chemical-toxicological investigations revealed gammahydroxybutyrat (GHB) in body fluids and tissues in the following quantities: femoral blood 390 mg/L, heart blood 420 mg/L, cerebrospinal fluid 420 mg/L, vitreous humor 640 mg/L, urine 1600 mg/L, and head hair 26.7 ng/mg. In addition, 1,4-BD was qualitatively detected in the head hair, urine, stomach contents, and the bottle. No other substances, including alcohol, were detected at pharmacologically relevant concentrations. 1,4-BD is known as precursor substance that is converted in vivo into GHB. In the synoptic assessment of toxicological findings, the police investigations and having excluded other causes of death, a lethal GHB-intoxication following ingestion of 1,4-BD, can be assumed in this case. Fatal intoxications with 1,4-BD have seldom been reported due to a very rapid conversion to GHB and, among other things, non-specific symptoms after ingestion. This case report aims to give an overview to the published of fatal 1,4-BD-intoxications and to discuss the problems associated with detection of 1,4-BD in (postmortem) specimens.

Histomorphometric analysis of osteocyte density and trabecular structure of 92 vertebral bodies of different ages and genders

BACKGROUND

Knowledge of the histomorphometric structure of the vertebral body and factors influencing the structure is essential for a fundamental understanding of osteoporosis and osteoporotic fractures. The present study is focused on osteocyte density - a parameter seldom investigated so far - and trabecular width as well as bone area over tissue area in human vertebral bodies.

METHODS

Ninety-two vertebral body specimens (C5, C6, Th8, Th12, L1, L2) from 12 males and seven females were studied (Ethics Application Number A 2017-0072). The prepared vertebral specimens were extracted from the ventral aspect with a Jamshidi needle®. The punches were decalcified and subsequently H&E stained. Using the Fiji/Image J program (version 1.53 f, Wayne Resband, National Institute of Mental Health, USA), osteocyte numbers were counted per calcified bone surface, and the trabecular width and bone area of trabecular bone were measured. The collected data were analyzed using the statistical software package SPSS, version 23.0 (SPSS Inc., Chicago, USA). Pearson's correlation coefficient was used for correlation analyses. Multiple linear regression analyses were also performed.

RESULTS

Osteocyte density did not differ significantly in comparisons based on gender and age (≤65 years; ≥66 years). Men had wider trabeculae (p < 0.001) and a higher bone area over tissue area (BA/TA, %) (p = 0.025) than women. Individuals over 65 years of age had thinner trabeculae (p < 0.001) and a smaller BA/TA (%) (p < 0.001) than younger individuals. Multiple linear regression analyses were performed to determine the influence of 'gender' and 'age' on trabecular width and bone area over tissue area. The R² was 0.388 for trabecular width and 0.227 for BA/TA (%). Per year of life, trabecular width decreases by 0.368 µm (β < 0.001) and BA/TA (%) by 0.001% (β = 0.001). Men have on average 8.2 µm wider trabeculae than women (β = 0.035). A negative correlation (r = -0.275) was observed between trabecular width and osteocyte density. The wider the trabeculae, the fewer osteocytes per mm² (p = 0.008).

CONCLUSIONS

Surprisingly, we found no difference in osteocyte density with reference to age or gender. However, we did register significant age- and gender-related differences in bone area over tissue area and trabecular thickness. The age-related differences were more pronounced, implying that age-dependent loss of bone structure may be more important than differences between genders.

[Caution: aggressive! Dog bite injuries in clinical forensic medicine]

Younger children in particular are at risk of becoming victims of dog attacks due to their small size. Such a biting incident can fulfil various criminal offences. In order to be able to satisfy possible legal claims, the injuries should be documented by forensic medicine and thus be legally binding. Therefore, close cooperation between the treating surgeons and forensic experts is recommended. A retrospective analysis of the cases of dog bite injuries in children and adults treated by clinical forensic medicine at the University Medical Center Rostock was carried out under various aspects. Adult casualties were predominantly injured on the lower extremities. The children examined were predominantly bitten on the head, neck and face region as well as the upper extremities. Injury severity ranged from skin redness to severe substance defects with loss of body structures. The biting dog was known in about half of the cases. In order to avoid dog bites in children, parents as well as children should be trained in dealing with dogs.

Nicht nur Doktorspiele – (rechts)medizinische Aspekte von Sexualdelikten an Kindern durch Kinder

Hintergrund

Sexualisierte Handlungen zwischen gleichaltrigen Kindern sind in der Regel Ausdruck eines normalen, altersgerechten Verhaltens. Doch auch zwischen Minderjährigen gibt es sexualisierte Gewalt, die über das altersentsprechende Interesse hinausgeht und in der medizinischen Literatur bislang wenig Beachtung fand.

Methode

Es wurde eine selektive Literaturrecherche in der Datenbank PubMed sowie mithilfe des Suchdienstes Google Scholar durchgeführt. Außerdem wurde eine retrospektive Analyse eigener Fälle durchgeführt.

Ergebnisse

Die erfassten Studien ergaben Prävalenzen von 6 bis 50,7 % für unerwünschte sexuelle Kontakte. SchülerIn an einer Highschool und weiblich zu sein oder einen Migrationshintergrund zu haben, wurde als Risikofaktor für sexuelle Übergriffe identifiziert. Mehr als die Hälfte (54 %) der Täterinnen und bis zu 16 % der Täter waren zuvor selber von Missbrauch und/oder Vernachlässigung betroffen. In der eigenen Erhebung gaben 37 % der Mädchen an, penovaginal penetriert worden zu sein, während 60 % der Jungen eine penoanale Penetration angaben. In keinem Fall konnten objektivierbare Verletzungen festgestellt werden.

Schlussfolgerung

Auch wenn bei der medizinischen Untersuchung von minderjährigen Geschädigten nach Sexualdelikten nur äußerst selten eindeutige Befunde festzustellen sind, sollte jede/jeder MedizinerIn Kenntnis über die Wertigkeit und Bedeutung von kindlichen Genitalbefunden haben. Weiterhin gilt es, den fließenden Übergang von „Doktorspielen“ zu sexualisierter Gewalt zwischen Minderjährigen korrekt zu erkennen.

Organ manifestations of COVID-19: what have we learned so far (not only) from autopsies?

The use of autopsies in medicine has been declining. The COVID-19 pandemic has documented and rejuvenated the importance of autopsies as a tool of modern medicine. In this review, we discuss the various autopsy techniques, the applicability of modern analytical methods to understand the pathophysiology of COVID-19, the major pathological organ findings, limitations or current studies, and open questions. This article summarizes published literature and the consented experience of the nationwide network of clinical, neuro-, and forensic pathologists from 27 German autopsy centers with more than 1200 COVID-19 autopsies. The autopsy tissues revealed that SARS-CoV-2 can be found in virtually all human organs and tissues, and the majority of cells. Autopsies have revealed the organ and tissue tropism of SARS-CoV-2, and the morphological features of COVID-19. This is characterized by diffuse alveolar damage, combined with angiocentric disease, which in turn is characterized by endothelial dysfunction, vascular inflammation, (micro-) thrombosis, vasoconstriction, and intussusceptive angiogenesis. These findings explained the increased pulmonary resistance in COVID-19 and supported the recommendations for antithrombotic treatment in COVID-19. In contrast, in extra-respiratory organs, pathological changes are often nonspecific and unclear to which extent these changes are due to direct infection vs. indirect/secondary mechanisms of organ injury, or a combination thereof. Ongoing research using autopsies aims at answering questions on disease mechanisms, e.g., focusing on variants of concern, and future challenges, such as post-COVID conditions. Autopsies are an invaluable tool in medicine and national and international interdisciplinary collaborative autopsy-based research initiatives are essential.

Intracranial hemorrhage in COVID-19 patients during extracorporeal membrane oxygenation for acute respiratory failure: a nationwide register study report

Background

In severe cases, SARS-CoV-2 infection leads to acute respiratory distress syndrome (ARDS), often treated by extracorporeal membrane oxygenation (ECMO). During ECMO therapy, anticoagulation is crucial to prevent device-associated thrombosis and device failure, however, it is associated with bleeding complications. In COVID-19, additional pathologies, such as endotheliitis, may further increase the risk of bleeding complications. To assess the frequency of bleeding events, we analyzed data from the German COVID-19 autopsy registry (DeRegCOVID).

Methods

The electronic registry uses a web-based electronic case report form. In November 2021, the registry included N = 1129 confirmed COVID-19 autopsy cases, with data on 63 ECMO autopsy cases and 1066 non-ECMO autopsy cases, contributed from 29 German sites.

Findings

The registry data showed that ECMO was used in younger male patients and bleeding events occurred much more frequently in ECMO cases compared to non-ECMO cases (56% and 9%, respectively). Similarly, intracranial bleeding (ICB) was documented in 21% of ECMO cases and 3% of non-ECMO cases and was classified as the immediate or underlying cause of death in 78% of ECMO cases and 37% of non-ECMO cases. In ECMO cases, the three most common immediate causes of death were multi-organ failure, ARDS and ICB, and in non-ECMO cases ARDS, multi-organ failure and pulmonary bacterial ± fungal superinfection, ordered by descending frequency.

Interpretation

Our study suggests the potential value of autopsies and a joint interdisciplinary multicenter (national) approach in addressing fatal complications in COVID-19.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03945-x.

Biomechanical comparisons of three minimally invasive Achilles tendon percutaneous repair suture techniques

BACKGROUND

While no gold standard exists for the management of Achilles tendon ruptures, surgical repair is common in healthy and active patients. Minimally invasive repair methods have become increasingly popular, while biomechanical equivalency hasn't been proven yet.

METHODS

A mid-substance Achilles tendon rupture was created 6 cm proximal to the calcaneal insertion in 27 fresh-frozen cadaveric ankles. Specimens were randomly allocated to 1 of 3 repair techniques: Huttunen et al. (2014) (1) PARS Achilles Jig System, Nyyssönen et al. (2008) (2) Achilles Midsubstance SpeedBridge™, Schipper and Cohen (2017) (3) Dresdner Instrument and subsequently subjected to cyclic loading with 250 cycles each at 1 Hz with 4 different loading ranges (20-100 N, 20-200 N, 20-300 N, and 20-400 N).

FINDINGS

After 250 cycles no significant differences in elongation were observed between PARS and Dresdner Instrument(p = 1.0). Furthermore, SpeedBridge™ repairs elongated less than either Dresdner Instrument (p = 0.0006) or PARS (p = 0.102). Main elongation (85%) occurred within the first 10 cycles with a comparable elongation in between 10 and 100 and 100-250 cycles. While all repairs withstood the first 250 cycles of cyclic loading from 20 to 100 N, only the PARS (468 ± 175) and Midsubstance SpeedBridge™ (538 ± 208) survived more cycles. Within all 3 groups suture cut out was seen to be the most common failure mechanism.

INTERPRETATION

Within all groups early repair elongation was seen. While this was least obvious within the SpeedBridge™ technique, ultimate strengths of repairs (cycles to failure) were comparable across PARS and SpeedBridge™ with a decline in the Dresdner Instrument group.

First report from the German COVID-19 autopsy registry

Background

Autopsies are an important tool in medicine, dissecting disease pathophysiology and causes of death. In COVID-19, autopsies revealed e.g., the effects on pulmonary (micro)vasculature or the nervous system, systemic viral spread, or the interplay with the immune system. To facilitate multicentre autopsy-based studies and provide a central hub supporting autopsy centres, researchers, and data analyses and reporting, in April 2020 the German COVID-19 Autopsy Registry (DeRegCOVID) was launched.

Methods

The electronic registry uses a web-based electronic case report form. Participation is voluntary and biomaterial remains at the respective site (decentralized biobanking). As of October 2021, the registry included N=1129 autopsy cases, with 69271 single data points including information on 18674 available biospecimens gathered from 29 German sites.

Findings

In the N=1095 eligible records, the male-to-female ratio was 1·8:1, with peaks at 65-69 and 80-84 years in males and >85 years in females. The analysis of the chain of events directly leading to death revealed COVID-19 as the underlying cause of death in 86% of the autopsy cases, whereas in 14% COVID-19 was a concomitant disease. The most common immediate cause of death was diffuse alveolar damage, followed by multi-organ failure. The registry supports several scientific projects, public outreach and provides reports to the federal health authorities, leading to legislative adaptation of the German Infection Protection Act, facilitating the performance of autopsies during pandemics.

Interpretation

A national autopsy registry can provide multicentre quantitative information on COVID-19 deaths on a national level, supporting medical research, political decision-making and public discussion.

Funding

German Federal Ministries of Education and Research and Health.

Hintergrund: Obduktionen sind ein wichtiges Instrument in der Medizin, um die Pathophysiologie von Krankheiten und Todesursachen zu untersuchen. Im Rahmen von COVID-19 wurden durch Obduktionen z.B. die Auswirkungen auf die pulmonale Mikrovaskulatur, das Nervensystem, die systemische Virusausbreitung, und das Zusammenspiel mit dem Immunsystem untersucht. Um multizentrische, auf Obduktionen basierende Studien zu erleichtern und eine zentrale Anlaufstelle zu schaffen, die Obduktionszentren, Forscher sowie Datenanalysen und -berichte unterstützt, wurde im April 2020 das deutsche COVID-19-Autopsieregister (DeRegCOVID) ins Leben gerufen.

Methoden: Das elektronische Register verwendet ein webbasiertes elektronisches Fallberichtsformular. Die Teilnahme ist freiwillig und das Biomaterial verbleibt am jeweiligen Standort (dezentrales Biobanking). Im Oktober 2021 umfasste das Register N=1129 Obduktionsfälle mit 69271 einzelnen Datenpunkten, die Informationen über 18674 verfügbare Bioproben enthielten, die von 29 deutschen Standorten gesammelt wurden.

Ergebnisse: In den N=1095 ausgewerteten Datensätzen betrug das Verhältnis von Männern zu Frauen 1,8:1 mit Spitzenwerten bei 65-69 und 80-84 Jahren bei Männern und >85 Jahren bei Frauen. Die Analyse der Sequenz der unmittelbar zum Tod führenden Ereignisse ergab, dass in 86 % der Obduktionsfälle COVID-19 die zugrunde liegende Todesursache war, während in 14 % der Fälle COVID-19 eine Begleiterkrankung war. Die häufigste unmittelbare Todesursache war der diffuse Alveolarschaden, gefolgt von Multiorganversagen. Das Register unterstützt mehrere wissenschaftliche Projekte, die Öffentlichkeitsarbeit und liefert Berichte an die Bundesgesundheitsbehörden, was zu einer Anpassung des deutschen Infektionsschutzgesetzes führte und die Durchführung von Obduktionen in Pandemien erleichtert.

Interpretation: Ein nationales Obduktionsregister kann multizentrische quantitative Informationen über COVID-19-Todesfälle auf nationaler Ebene liefern und damit die medizinische Forschung, die politische Entscheidungsfindung und die öffentliche Diskussion unterstützen.

Finanzierung: Bundesministerien für Bildung und Forschung und für Gesundheit.

[Update on collaborative autopsy-based research in German pathology, neuropathology, and forensic medicine]

BACKGROUND

Autopsies are a valuable tool for understanding disease, including COVID-19.

MATERIALS AND METHODS

The German Registry of COVID-19 Autopsies (DeRegCOVID), established in April 2020, serves as the electronic backbone of the National Autopsy Network (NATON), launched in early 2022 following DEFEAT PANDEMIcs.

RESULTS

The NATON consortium's interconnected, collaborative autopsy research is enabled by an unprecedented collaboration of 138 individuals at more than 35 German university and non-university autopsy centers through which pathology, neuropathology, and forensic medicine autopsy data including data on biomaterials are collected in DeRegCOVID and tissue-based research and methods development are conducted. More than 145 publications have now emerged from participating autopsy centers, highlighting various basic science and clinical aspects of COVID-19, such as thromboembolic events, organ tropism, SARS-CoV‑2 detection methods, and infectivity of SARS-CoV-2 at autopsy.

CONCLUSIONS

Participating centers have demonstrated the high value of autopsy and autopsy-derived data and biomaterials to modern medicine. The planned long-term continuation and further development of the registry and network, as well as the open and participatory design, will allow the involvement of all interested partners.

Forensisch-medizinische Untersuchungen von Tatverdächtigen. Eine Analyse von 270 Gutachten aus den Jahren 2006 bis 2018

Hintergrund

Zu den Aufgaben in der rechtsmedizinischen Praxis gehören zunehmend forensisch-medizinische Untersuchungen von Lebenden. Im Gegensatz zu Studien über Gewaltopfer findet sich in der Fachliteratur allerdings ein erhebliches Defizit an Ergebnissen über systematische rechtsmedizinische Untersuchungen von Tatverdächtigen.

Fragestellung

Welche relevanten Daten können aus einer retrospektiven Analyse von forensisch-medizinischen Untersuchungen von Tatverdächtigen erhoben und welche Rückschlüsse für die rechtsmedizinische Praxis gezogen werden?

Material und Methode

Es wurden insgesamt 270 Gutachten nach forensisch-medizinischen Untersuchungen von Tatverdächtigen aus dem Einzugsgebiet des Instituts für Rechtsmedizin der Universitätsmedizin Rostock der Jahre 2006 bis 2018 nach vorab definierten Kriterien ausgewertet.

Ergebnisse

Die vorgeworfenen Straftaten waren am häufigsten Körperverletzungen (n = 88 = 30,7 %), gefolgt von vorsätzlichen Tötungen (n = 63 = 22,0 %) und Sexualdelikten (n = 49 = 17,1 %). Von den begutachteten Personen waren 236 (87,4 %) männlich und 34 (12,6 %) weiblich. Die Mehrzahl der Tatverdächtigen (n = 175 = 65,5 %) war in einem Lebensalter von 18 bis 40 Jahren.

Im Hinblick auf die Aussage der rechtsmedizinischen Ergebnisse in Bezug auf den vorgeworfenen Straftatbestand wurden 126 (46,7 %) Gutachten als für den Tatverdächtigen belastend, 13 (4,8 %) als entlastend und 131 (48,5 %) als frei von Be- oder Entlastungsaussagen eingestuft.

Zu den 270 Gutachten über Tatverdächtige gab es 209 (77,4 %) korrespondierende Opferuntersuchungen. Von diesem Teilkollektiv mit Täter-Opfer-Begutachtungen wurden in 193 Fällen (92,3 %) Tatverdächtige und Opfer von demselben Gutachter untersucht.

Schlussfolgerungen

Für die Rekonstruktion eines Tatgeschehens sind rechtsmedizinische Untersuchungen des Opfers und des Tatverdächtigen wertvoller als die nicht selten beobachtete Untersuchung der geschädigten Person allein. Befunde mit belastenden Tendenzen für den Tatverdächtigen werden häufiger festgestellt als solche, die zu einer Entlastung des Beschuldigten führen. Da es in der Fachliteratur im Vergleich zu den Opfern von Gewalttaten ein Defizit an Ergebnissen über systematische forensisch-medizinische Untersuchungen von Tatverdächtigen gibt, sollten weitere Studien folgen.

Primary stability of the Activ L® intervertebral disc prosthesis in cadaver bone and comparison of the keel and spike anchoring concept

Background

High primary stability is the key prerequisite for safe osseointegration of cementless intervertebral disc prostheses. The aim of our study was to determine the primary stability of intervertebral disc prostheses with two different anchoring concepts – keel and spike anchoring.

Methods

Ten ActivL intervertebral disc prostheses (5 x keel anchoring, 5 x spike anchoring) implanted in human cadaver lumbar spine specimens were tested in a spine movement simulator. Axial load flexion, extension, left and right bending and axial rotation motions were applied on the lumbar spine specimens through a defined three-dimensional movement program following ISO 2631 and ISO/CD 18192-1.3 standards. Tri-dimensional micromotions of the implants were measured for both anchor types and compared using Student’s T-test for significance after calculating 95 % confidence intervals.

Results

In the transverse axis, the keel anchoring concept showed statistically significant (p < 0.05) lower mean values of micromotions compared to the spike anchoring concept. The highest micromotion values for both types were observed in the longitudinal axis. In no case the threshold of 200 micrometers was exceeded.

Conclusions

Both fixation systems fulfill the required criteria of primary stability. Independent of the selected anchorage type an immediate postoperative active mobilization doesn’t compromise the stability of the prostheses.

Quantitative evidence of suppressed TMEM119 microglial immunohistochemistry in fatal morphine intoxications

The aim of this pilot study was to investigate the diagnostic potential of TMEM119 as a useful microglia-specific marker in combination with immunostainings for phagocytic function and infiltrating capacity of monocytes in cases of lethal monosubstance intoxications by morphine (MOR), methamphetamine (METH), and of ethanol-associated death (ETH) respectively. Human brain tissue samples were obtained from forensic autopsies of cases with single substance abuse (MOR, n = 8; ETH, n = 10; METH, n = 9) and then compared to a cohort of cardiovascular fatalities as controls (n = 9). Brain tissue samples of cortex, white matter, and hippocampus were collected and stained immunohistochemically with antibodies against TMEM119, CD68KiM1P, and CCR2. We could document the lowest density of TMEM119-positive cells in MOR deaths with highly significant differences to the control densities in all three regions investigated. In ETH and METH deaths, the expression of TMEM119 was comparable to cell densities in controls. The results indicate that the immunoreaction in brain tissue is different in these groups depending on the drug type used for abuse.

Mongolian Spots - A challenging clinical sign

Mongolian Spots (MS) are the most common birthmarks in newborn children. The condition presents as greenish-bluish to greyish macules, particularly in the lumbosacral area. The incidents of MS can vary in different ethnic groups and normally fade in early childhood. MS can be misinterpreted as hematomas because of the color and the predilection site. This paper discusses the case of a two-month old female admitted to hospital under suspicion of child abuse. The clinical forensic examination of the infant and her two older sisters found the children were in good health and did not show signs of abuse, despite the infant presenting with multiple and extensive greyish-blue macules. Thirteen months later, a welfare officer requested another forensic examination on the now 15-month-old child after noticing greyish-blue macules. Following a second examination, no evidence of abuse was found. This case illustrates the issue of MS as a differential diagnosis of hematomas.

Correlation between Kir4.1 expression and barium-sensitive currents in rat and human glioma cell lines

Gliomas are the most common primary brain tumors and often become apparent through symptomatic epileptic seizures. Glial cells express the inwardly rectifying K+ channel Kir4.1 playing a major role in K+ buffering, and are presumably involved in facilitating epileptic hyperexcitability. We therefore aimed to investigate the molecular and functional expression of Kir4.1 channels in cultured rat and human glioma cells. Quantitative PCR showed reduced expression of Kir4.1 in rat C6 and F98 cells as compared to control. In human U-87MG cells and in patient-derived low-passage glioblastoma cultures, Kir4.1 expression was also reduced as compared to autopsy controls. Testing Kir4.1 function using whole-cell patch-clamp experiments on rat C6 and two human low-passage glioblastoma cell lines (HROG38 and HROG05), we found a significantly depolarized resting membrane potential (RMP) in HROG05 (-29 ± 2 mV, n = 11) compared to C6 (-71 ± 1 mV, n = 12, P < 0.05) and HROG38 (-60 ± 2 mV, n = 12, P < 0.05). Sustained K+ inward or outward currents were sensitive to Ba2+ added to the bath solution in HROG38 and C6 cells, but not in HROG05 cells, consistent with RMP depolarization. While immunocytochemistry confirmed Kir4.1 in all three cell lines including HROG05, we found that aquaporin-4 and Kir5.1 were also significantly reduced suggesting that the Ba2+-sensitive K+ current is generally impaired in glioma tissue. In summary, we demonstrated that glioma cells differentially express functional inwardly rectifying K+ channels suggesting that impaired K+ buffering in cells lacking functional Ba2+-sensitive K+ currents may be a risk factor for increased excitability and thereby contribute to the differential epileptogenicity of gliomas.

Enterokolitis als Ursache eines akuten unerwarteten Todes eines Orang-Utans in Zoohaltung

Es wird von einem 13 Jahre alt gewordenen weiblichen Orang-Utan berichtet, der 4 Tage vor dem Tod an einer akuten Enterokolitis erkrankte. Die tierärztliche Ultraschalluntersuchung einen Tag vor dem Tod erbrachte den Nachweis von vermehrter Flüssigkeit im Zäkum und einer abschnittsweise verdickten Kolonwand. Nach dem für die Veterinärmediziner und die Zoomitarbeiter unerwarteten Todeseintritt erfolgte eine Obduktion durch Rechtsmediziner der Universitätsmedizin Rostock mit Unterstützung von Ärzten weiterer Fachrichtungen. Dabei wurde als Todesursache eine akute Escherichia-coli-Enterokolitis mit massiver Blutung in den Darm festgestellt. Begünstigend oder ursächlich für die letale Enterokolitis dürften wahrscheinlich zahlreiche rezidivierende Durchfallerkrankungen in der Anamnese des Orang-Utans als Folge eines Verweigerns des Stillens durch die Mutter nach der Geburt gewesen sein.

Influence of different fixation methods on the fracture force of osteoporotic human lumbar vertebral bodies in the generation of vertebral compression fractures

BACKGROUND

The use of fresh-frozen (FF) specimens represents the gold standard for biomechanical investigations. Since FF specimens are often difficult to obtain, chemical-fixed specimens (formalin (FA), Thiel (TH)) are also used.

OBJECTIVE

Since fixation methods can alter the mechanical properties of bone tissue, the purpose of this study was to examine their influence on the fracture force of lumbar vertebral bodies (VB).

METHODS

First the VB were subdivided into three focus groups: FF, TH, and FA. After removing the soft tissue and the processus transverses of all VB, the endplates were planned with a thin layer of epoxy resin, in order to apply a constant strain to the surface and sub-surface. The VB were subjected to axial compression tests in order to determine fracture force. Lastly a standardized compression fracture was generated.

RESULTS

The mean values of the fracture force of the focus groups were 4529.5 N (FF), 3211.3N (TH) and 2947.9N (FA). Consequently a significant difference between the FF and the other two groups could be demonstrated (p< 0.05).

CONCLUSION

The preliminary tests showed that the fraction force of fresh-frozen VB were significantly higher than TH/FA-fixed VB. Therefore, these fixation methods could potentially have an influence on the biomechanical properties of VB. This leads to the assumption that if load-to-failure tests are performed, it is probably recommended to use fresh-frozen specimens.

Rupture of intracranial aneurysms in patients with blunt head trauma: Review of the literature

INTRODUCTION

With a prevalence of 1-5 %, intracranial aneurysms are common. However, only 20-50 % of these aneurysms will rupture during a person's lifetime. This often happens spontaneously without exogenous factors. In the present study we reviewed the literature concerning the relation between trauma and rupture of a pre-existing aneurysm.

METHODS

All studies that reported a causal relation between trauma and rupture of a pre-existing aneurysm were included, irrespective of study design. They were limited though to those written in English or German. Excluded were studies with traumatic aneurysms, studies where the rupture of an aneurysm lead to trauma and studies with doubts about the order of events.

RESULTS

Thirteen studies with twenty-two cases of ruptured aneurysm in context with trauma and two unpublished cases were included. Fourteen patients were involved in a fight, seven patients in a bike/motorbike/bus accident and three got hit on the head in a setting outside of interpersonal violence. The aneurysm was located in internal carotid artery in most cases (7/24). The clear majority of patients (19/24) did not survive.

CONCLUSION

Arteries and aneurysms can rupture in context with head trauma although this is rarely the case. Patients after head trauma with typical blood pattern for aneurysmal SAH in the native CT scan should receive conventional angiography to exclude a vascular or aneurysmal rupture, even when CT-angiography is inconspicuous.

Domestic Violence Against Men-Prevalence and Risk Factors

BACKGROUND

According to the World Health Organization (WHO), intimate partner violence is among the major risks to women's health around the world. Men, too, can be victims of domestic violence; like female victims, they tend to present initially with their injuries to a family physician or an emergency room. Domestic violence against men is thus a relevant issue for physicians of all specialties.

METHODS

This review is based on publications retrieved by a comprehensive, selective search in the PubMed database and with the Google Scholar search service, as well as on a retrospective analysis of data on the injured persons, the aggressors, and the nature of the violence that was experienced and the injuries that were sustained.

RESULTS

The studies identified by the search yielded prevalence rates of 3.4% to 20.3% for domestic physical violence against men. Most of the affected men had been violent toward their partners themselves. 10.6-40% of them reported having been abused or maltreated as children. Alcohol abuse, jealousy, mental illness, physical impairment, and short relationship duration are all associated with a higher risk of being a victim of domestic violence. The reported consequences of violence include mostly minor physical injuries, impaired physical health, mental health problems such as anxiety or a disruptive disorder, and increased consumption of alcohol and/or illegal drugs.

CONCLUSION

The prevalence of violence against men and the risk factors for it have been little studied to date. It would be desirable for preventive measures to be further developed and for special help to be made available to the affected men.

The adulterated XANAX pill: a fatal intoxication with etizolam and caffeine

A 49-year old man was found dead at home next to a glass containing a dried, white, crystalline substance and near a bag containing pills with the imprint XANAX, the trade name of alprazolam. A comprehensive screening of material collected during the autopsy revealed the presence of etizolam and caffeine in lethal concentrations (0.77 μg/mL and 190 μg/mL) but no trace of alprazolam. Benzodiazepine analogue etizolam is rarely prescribed in Germany, and as a result there are not many reports about fatal cases. It has anxiolytic, hypnotic, sedative and muscle-relaxant properties and is used for the short-term treatment of anxiety and panic attacks. The purine alkaloid caffeine, conversely, is the most widely used central nervous system stimulant. The following report outlines potentially the first reported case of a lethal combination of the downer etizolam and the upper caffeine in medical literature.

Lesions and characteristic injury patterns caused by high-voltage fault arcs

Exposure to high-voltage electric arcs as a result of an accident or by means to commit suicide can affect people's health and cause death. There are characteristic external findings that can be found on external examination. These include extensive skin burns, periorbital recesses or "crow's feet," vapor deposition of conductor material, known as metallization, and tightly spaced, roundish, crocodile skin like burns. The Institute of Legal Medicine of the Rostock University Medical Center recorded 16 deaths caused by exposure to electricity between 1990 and 2018. Six of these deaths were caused by exposure to high-voltage electric arcs and five of these deaths (83 %) showed crocodile skin like burns and one had periorbital recesses burns on the face as a result of a fault arc. To our knowledge, the present paper is the first report describing the frequent occurrence of crocodile skin like burns due to high-voltage fault arcs.

Deactivation of cardiovascular implantable electronic devices in patients nearing end of life : Reality or only recommendation?

BACKGROUND

Current guidelines recommend considering deactivation of cardiac implantable electronic devices (CIEDs) in patients nearing death. We evaluated the implementation of this recommendation in unselected deceased individuals with CIEDs.

METHODS

Over a 7-month period in 2016, all deceased persons taken to the Rostock crematorium were prospectively screened for CIEDs and these were interrogated in situ. Pacing rate, pacing mode, and lead output were documented as well as patient data including location and time of death. In implantable cardioverter-defibrillators (ICDs), tachycardia therapy adjustment and occurrence of shocks 24 h prior to death were also recorded.

RESULTS

We examined 2297 subjects, of whom 154 (6.7%) had CIEDs. Of these subjects, 125 (100%) pacemakers (PMs) and 27 (96.4%) ICDs were eligible for analysis. Death in persons with ICDs occurred most frequently in hospital (55.6%), while this was less frequently the case for individuals with PMs (43.2%). Furthermore, 33.3% of subjects with ICDs and 18.5% with PMs died in palliative care units (PCU). Shock therapies were switched off in three (60%) individuals with ICDs who died in the PCU, whereas antibradycardia therapy was not withdrawn in any PM patient in the PCU. Therapy withdrawal occurred in two patients with PMs (1.3%) who died in hospital. Patients with PMs had high ventricular pacing rates at the last interrogation (69 ± 36.0%) and often suffered atrioventricular block (39.2%). Six (25%) of the 24 active ICDs presented shocks near the time of death.

CONCLUSION

Many CIED patients died in hospital; nonetheless, in practice, CIED deactivation near death is rarely performed and might be less feasible in subjects with PMs. However, there is still a need to consider deactivation, especially in individuals with ICDs, as one fourth of them received at least one shock within 24 h prior to death.

Individual programming of current multiprogrammable pacemakers : Still unsatisfactory?

BACKGROUND

Pacemaker (PM) technology has developed tremendously in recent decades. We evaluated the extent of individual programming in current PMs.

METHODS

Over a 7-month period in 2016, all deceased persons taken to the Rostock crematorium were prospectively screened for cardiac implantable electronic devices (CIEDs) and these were interrogated in situ. Programming of patient data, leads, and study parameters including mode, lower rate, upper tracking or sensor rate (UTSR), ventricular refractory time, sleeping function, hysteresis, and PM-mediated tachycardia intervention were analyzed and compared with delivery settings. Alterations in atrial/ventricular capture management and atrial/ventricular sensing assurance as well as changes in sensitivity and lead output were evaluated.

RESULTS

We examined 2297 subjects, of whom 154 (6.7%) had CIEDs, with 125 (81.2%) being PMs. Finally, 72 (57.6%) PMs were eligible for analysis with an operation time of 31.0 ± 27.0 months. We excluded 28 (18.2%) implantable cardioverter defibrillators (ICDs), 51 (41%) PMs presenting elective replacement indicator (ERI), two (1.6%) PMs with programming to insufficient function prior to death, and the left ventricle parameter of one (1.4%) cardiac resynchronization therapy pacemaker (CRT-P); further one CIED (0.6%) was not contactable. PMs offered in mean 75.2% of study parameters thereof 88.0% were to adjust manually, whereof 49.3% stayed unchanged to delivery mode. Lead output, UTSR, lower rate, and mode were the most frequently changed parameters (>85.7%, 65.3%, 54.2%, and 52.8%, respectively) compared with unmodified ventricular refractory time and hysteresis (91.7% and. 85.4%, respectively); 2.8% of PMs had out-of-the-box settings. The most frequent personalized data were last (88.9%) and first name (73.6%), while atrial and ventricular serial lead numbers were rarely entered (18.2% and 23.4%, respectively).

CONCLUSION

The programming possibilities of PMs have advanced greatly. Nonetheless, improvements in individual PM programming are still needed as demonstrated by the findings in this study, e.g., PMs with manufacturer settings and lack of individual data.

Fracture generation in human vertebrae under compression loading: The influence of pedicle preservation and bone mineral density on in vitro fracture behavior

BACKGROUND

Fractured vertebral bodies are a common and wide spread health issue.

OBJECTIVE

The purpose of this study was to develop a standardized method to experimentally generate compression fractures in vertebral bodies. The influence of the pedicles has been investigated with regards to the fracture behavior. The correlation between bone mineral density (BMD), the cause of fractures and the fracture behavior was investigated.

METHODS

Twenty-one fresh frozen human lumbar spines were examined for bone mineral density (BMD) by means of quantitative computed tomography (qCT). All soft tissue was removed, vertebrae were carefully separated from each other and the exposed cranial and caudal endplates were covered with a thin layer of resin to generate a plane and homogeneous surface. A total of 80 vertebral bodies were tested until fracture.

RESULTS

A good positive correlation was found between BMD, fracture compression force and stiffness of the vertebral body. No significant differences were found between the fractures generated in vertebral bodies with and without pedicles, respectively.

CONCLUSIONS

Our model represents a consolidation of already existing testing devices. The comparative measurement of the BMD and the fracture behavior shows validity. In contrast to other authors, the force was applied to the whole vertebral body. Furthermore the upper and lower plates were not parallelized and therefore the natural anatomic shape was imitated. Fracture behavior was not altered by removing the pedicles.

Unusual head injury by a forklift vehicle

A case of an unusual head injury by a forklift vehicle is presented.

Erste-Nacht-Effekt bei schlafbezogenen Atmungsstörungen

Bekannterweise existiert bei Patienten mit dokumentiertem obstruktiven Schlafapnoe-Syndrom (OSAS) eine Nacht-zu- Nacht-Variabilität der Apnoen/Hypopnoen während der nächtlichen Polysomnografie (PSG). Diese könnte dazu führen, erkrankte Patienten nicht oder nicht rechtzeitig zu erkennen und angemessen zu behandeln und somit ein erhöhtes Risiko für eine massive Verschlechterung des OSAS und/oder Folgeerkrankungen kardiologischer und/oder neurologischer Art zu provozieren. In dieser Studie untersuchten wir, ob bzw. inwieweit die Möglichkeit besteht, dass diese Variabilität aufgrund der fortschreitenden Mittelkürzungen im Gesundheitswesen dazu führen kann, OSAS-Patienten nicht diagnostizieren zu können, zu spät zu behandeln oder unbehandelt zu lassen. Die Untersuchung erfolgte intraindividuell an einer Gruppe von 100 OSAS-Patienten (17 weiblich). Alle Studienteilnehmer wurden polysomnografisch sowohl in der ersten als auch in der zweiten Nacht untersucht und mussten alle zur OSASDiagnose notwendigen Kriterien aufweisen. Das Untersuchungsdesign sah den Vergleich der beiden Diagnosenächte vor. Die Überprüfung ergab einen signifikanten Unterschied (p < 0,001). Bei 72% kam es in der zweiten PSG-Nacht zu einer Erhöhung des AHI. In unserer Untersuchung zeigte sich, dass die nächtlichen Apnoen/Hypopnoen beim OSAS zwischen erster und zweiter PSG-Nacht so stark variieren, dass die Erkrankung bei 40% aller Fälle nach nur einer PSG-Nacht zu einer Fehldiagnostik führen würde.

Delineation of Subregions in the Early Postnatal Human Cerebellum for Design-Based Stereologic Studies

Recent design-based stereologic studies have shown that the early postnatal (<1 year of age) human cerebellum is characterized by very high plasticity and may thus be very sensitive to external and internal influences during the first year of life. A potential weakness of these studies is that they were not separately performed on functionally relevant subregions of the cerebellum, as was the case in a few design-based stereologic studies on the adult human cerebellum. The aim of the present study was to assess whether it is possible to identify unequivocally the primary, superior posterior, horizontal, ansoparamedian, and posterolateral fissures in the early postnatal human cerebellum, based on which functionally relevant subregions could be delineated. This was tested in 20 human post mortem cerebellar halves from subjects aged between 1 day and 11 months by means of a combined macroscopic and microscopic approach. We found that the superior posterior, horizontal, and posterolateral fissures can be reliably identified on all of the specimens. However, reliable and reproducible identification of the primary and ansoparamedian fissures was not possible. Accordingly, it appears feasible to perform subregion-specific investigations in the early postnatal human cerebellum when the identification of subregions is restricted to crus I (bordered by the superior posterior and horizontal fissures) and the flocculus (bordered by the posterolateral fissure). As such, it is recommended to define the entire cerebellar cortex as the region of interest in design-based stereologic studies on the early postnatal human cerebellum to guarantee reproducibility of results.

Gene expression analysis of growth factor receptors in human chondrocytes in monolayer and 3D pellet cultures

The main goal of cartilage repair is to create functional tissue by enhancing the in vitro conditions to more physiological in vivo conditions. Chondrogenic growth factors play an important role in influencing cartilage homeostasis. Insulin‑like growth factor (IGF)‑1 and transforming growth factor (TGF)‑β1 affect the expression of collagen type II (Col2) and glycosaminoglycans (GAGs) and, therefore, the targeted use of growth factors could make chondrogenic redifferentiation more efficient. In the present study, human chondrocytes were postmortally isolated from healthy articular cartilage and cultivated as monolayer or 3D pellet cultures either under normoxia or hypoxia and stimulated with IGF‑1 and/or TGF‑β1 to compare the impact of the different growth factors. The mRNA levels of the specific receptors (IGF1R, TGFBR1, TGFBR2) were analyzed at different time points. Moreover, gene expression rates of collagen type 1 and 2 in pellet cultures were observed over a period of 5 weeks. Additionally, hyaline‑like Col2 protein and sulphated GAG (sGAG) levels were quantified. Stimulation with IGF‑1 resulted in an enhanced expression of IGF1R and TGFBR2 whereas TGF‑β1 stimulated TGFBR1 in the monolayer and pellet cultures. In monolayer, the differences reached levels of significance. This effect was more pronounced under hypoxic culture conditions. In pellet cultures, increased amounts of Col2 protein and sGAGs after incubation with TGF‑β1 and/or IGF‑1 were validated. In summary, constructing a gene expression profile regarding mRNA levels of specific growth factor receptors in monolayer cultures could be helpful for a targeted application of growth factors in cartilage tissue engineering.

Alcohol-related diseases

Alcohol abuse and dependence are serious medical and economic problems in Western countries. Brain changes encountered in alcoholism are manifold and encompass brain atrophy, selective neuronal loss, astroglial, and microglial changes. Alcohol-related disorders are complex multifactorial disorders where the interaction of multiple genes and environment plays an important role in the pathogenesis.

Neurotoxicology and drug-related disorders

Neuropsychiatric disorders caused by toxic substances pose a great diagnostic challenge due to the large variety of changes caused in the central and peripheral nervous system. The pathogenetic mechanisms at work are multifaceted and partly not solved. In human drug abusers (cannabis, opiates, cocaine, amphetamines, methamphetamine and "designer drugs"), a broad spectrum of central nervous system alterations are observed including infarction, intracerebral and subarachnoidal hemorrhage, hypoxic-ischemic leukoencephalopathy, infections, neuronal loss, specific astroglial and microglial reaction patterns, and vascular changes, including the endothelial cell as well as the basal lamina.

[Unexpected Complications in the Withdrawal Treatment of the Research Chemical AH-7921]

We describe the case of a young male patient who had consumed the morphine-like substance AH-7921 which is available via the internet. He was initially admitted to hospital because of obstipation and presented within a day of inpatient treatment for the first time with a generalized tonic-clonic epileptic seizure with subsequent urinary retention. Within a few hours, the patient then also developed bradycardia, while at the same time describing symptoms of physical opioid withdrawal which gradually deteriorated within the following hours. We initiated a treatment with buprenorphine which resulted in a considerable reduction of withdrawal symptoms, so the patient could be discharged from hospital.

[Autopsies for anatomical teaching and training in clinical forensic medicine]

BACKGROUND

Clinical forensic medicine does not only entail examination of patients after physical violence but also the option of clinical autopsies, e.g. after non-notifiable complications of medical interventions, after fatalities closely following medical interventions or fatalities as a result of injuries when the public prosecutor decides not to order a medicolegal autopsy. Based on this routine the Institute of Forensic Medicine at the University of Rostock offers a training course in topographical anatomy to physicians for further training in interventional and surgical disciplines.

METHODS

At the beginning of autopsies the participants can explore the approaches of interventional puncture techniques as well as surgical techniques and the basic topographical anatomy in small groups of 2-4 persons under the supervision of forensic examiners. The format is essentially oriented to the early further training period but fulfils the requirements for the exploration of complex operative techniques. The course was adapted for physicians and offered separately to students. The explorations are performed manually or by support with autopsy instruments.

RESULTS

The courses offer an ideal room for individual, discipline-specific topics and result in a great benefit for all participants. A statistical assessment can only be achieved with a larger number of participants.

CONCLUSION

Making autopsy rooms available for teaching and further training represents an additional feature to the profile of clinical forensic medicine. Lessons in topographical anatomy provide a great benefit for patient safety. It seems to be important to offer the opportunity to address individual interests in a closed meeting to consolidate skills and abilities in a non-judgemental environment. The post-mortem examiners have to ensure that the autopsy is carried out lege artis. Basic ethical principles and all regulations from an accredited scope have to be adhered to.

Histologic spectrum of the cardiac conducting tissue in non-natural deaths under 30 years of age: an analysis of 43 cases with special implications for sudden cardiac death

In the past, histological findings of the cardiac conduction system or its adjacent structures, such as filiform fibers at the transition from bundle of His to bundle branches, connective tissue at the apex of the ventricular septum, or fibromuscular alterations of the arteries has been considered as a cause of death. However, the prevalence of such findings in a healthy population has been rarely analyzed systematically. In the present study, the morphology of the cardiac conduction system of 43 heart-healthy individuals who died of non-natural causes (ages 0 to 30 years) was investigated. In a high percentage of cases, connective tissue at the apex of the ventricular septum (97.7%), filiform fibers at the transition from bundle of His to the bundle branches (27.9%), and fibromuscular proliferations of the sinoatrial node artery (41.9%), and the AV-node artery (39.5%) could be detected. Based on our observations, these alterations should not be considered as a pathologic entity or as a cause of death.

Alterations of neuronal precursor cells in stages of human adult neurogenesis in heroin addicts

BACKGROUND

Adult neurogenesis has been shown to occur throughout life and different brain pathologies were demonstrated to be associated with altered neurogenesis. Here, an impact of heroin addiction on neurogenesis in humans is hypothesised.

METHODS

Post mortem hippocampal specimens of drug addicts with known heroin abuse and a group of non-addictive control subjects were analysed, using antibodies indicating different stages of neurogenesis. The subgranular zone of the dentate gyrus was examined qualitatively and quantitatively.

RESULTS

The data indicate (i) a decreased number of neural precursor cells, (ii) accompanied by low rates of proliferation and (iii) a marked loss of dendritic trees in targeting cells in heroin fatalities. (iv) The age-dependent increase of differentiating cells in the healthy controls was not observed in the addicts. Additionally, double immunofluorescence labelling indicated the precursor nature of Musashi-1 positive cells in the human subgranular zone of the dentate gyrus.

CONCLUSIONS

Present data firstly demonstrate the influence of drug addiction with known heroin abuse on different developmental stages of progenitors in the dentate gyrus. The patterns of antibody staining suggest a distinct inhibition of neurogenesis at the stage of neural precursor cells and revealed morphological changes in targeting cells in cases of heroin addicts as compared to healthy controls. These alterations could be considerable for memory and cognitive deficits as well as addictive behaviour in chronic drug abusers and may give rise to specific pro-neurogenic therapies.

Distinction between forensic evidence and dermatological findings

The external examination after death requires knowledge in forensics/pathology, dermatology, as well as associated diseases and age-related alterations of the skin. This article highlights some findings with forensic evidence versus dermatological findings. The lectures in forensic medicine should be structured interdisciplinarily, especially to dermatology, internal medicine, surgery, pathology, and toxicology in order to train the overlapping skills required for external and internal postmortem examinations.