Single Nuclei Sequencing Reveals Novel Insights Into the Regulation of Cellular Signatures in Children With Dilated Cardiomyopathy

BACKGROUND

Dilated cardiomyopathy (DCM) is a leading cause of death in children with heart failure. The outcome of pediatric heart failure treatment is inconsistent, and large cohort studies are lacking. Progress may be achieved through personalized therapy that takes age- and disease-related pathophysiology, pathology, and molecular fingerprints into account. We present single nuclei RNA sequencing from pediatric patients with DCM as the next step in identifying cellular signatures.

METHODS

We performed single nuclei RNA sequencing with heart tissues from 6 children with DCM with an age of 0.5, 0.75, 5, 6, 12, and 13 years. Unsupervised clustering of 18 211 nuclei led to the identification of 14 distinct clusters with 6 major cell types.

RESULTS

The number of nuclei in fibroblast clusters increased with age in patients with DCM, a finding that was confirmed by histological analysis and was consistent with an age-related increase in cardiac fibrosis quantified by cardiac magnetic resonance imaging. Fibroblasts of patients with DCM >6 years of age showed a profoundly altered gene expression pattern with enrichment of genes encoding fibrillary collagens, modulation of proteoglycans, switch in thrombospondin isoforms, and signatures of fibroblast activation. In addition, a population of cardiomyocytes with a high proregenerative profile was identified in infant patients with DCM but was absent in children >6 years of age. This cluster showed high expression of cell cycle activators such as cyclin D family members, increased glycolytic metabolism and antioxidative genes, and alterations in ß-adrenergic signaling genes.

CONCLUSIONS

Novel insights into the cellular transcriptomes of hearts from pediatric patients with DCM provide remarkable age-dependent changes in the expression patterns of fibroblast and cardiomyocyte genes with less fibrotic but enriched proregenerative signatures in infants.

Estimates of Non-Alcoholic Food-Derived Ethanol and Methanol Exposure in Human

Food-derived alcohol is almost not in question due to its low concentration. Nevertheless, could it pose a problem for some risk groups and forensic cases? To answer this, we aimed to simultaneously evaluate ethanol and methanol ingredients of a variety of non-alcoholic foods in two different countries and estimate their possible health and forensic consequences. Alcohols in foods were analysed by headspace gas chromatography (HS-GC). Human average acute daily food consumptions and food-derived blood alcohol concentrations (BAC) were determined by using the data of the EFSA Nutrition Survey. Methanol and ethanol ingredients of similar foods varied between the two cities. Most foods produce higher methanol concentrations than the Maximum Allowable Dose Level (23 mg). Especially fruit juices lead to the critical level of ethanol for children (6.0 mg/kg bw). Based on the results, adult daily intake of selected food groups does not bear ethanol that exceeds the legal limit of BAC or the limit not allowed by the religious and does not lead to acute alcohol toxicity. But these low levels of ethanol and methanol consumed via non-alcoholic foods for life can raise the vulnerability to chronic health problems (cancer, liver cirrhosis, Alzheimer's disease, autism, ocular toxicity, alterations in fetal development), and may lead to positive ethanol metabolite results (e. g. Ethyl glucuronide) when a low cut-off level is used. Therefore, studies on the alcohol contents of various natural and processed non-alcoholic foods along with their effects on humans, and new regulations on labeling the food products and conscious food consumption are in particular importance. It would also be important to consider unintentional alcohol consumption via non-alcoholic foods in the evaluation of clinical and forensic cases.

[National and international aspects of the medico-legal examination of injured witnesses and defendants in criminal proceedings]

Depending on the type of offence, the medico-legal examination of victims of violence for the purpose of collecting evidence in criminal proceedings requires prompt physical examination of the victim, the exact description and, wherever possible, photographic documentation of the injuries and their forensically correct interpretation. Examination, documentation and assessment have to meet minimum standards. In addition it must be ensured that the examiner or expert has an independent organisational, administrative and financial status. An independent expert must not be an organisational part of the police force, the public prosecution and the court. Legal regulations have to make sure that the expert cannot be influenced "through official channels". His or her financial independence must make attempted bribery at least improbable. The independence of the expert is particularly important, if persons become victims of violence while they are under the custody of the state, especially the police, in prisons and after compulsory commitment to a psychiatric hospital.

Comparative lipidomic analysis of synovial fluid in human and canine osteoarthritis

OBJECTIVE

The lipid profile of synovial fluid (SF) is related to the health status of joints. The early stages of human osteoarthritis (OA) are poorly understood, which larger animals are expected to be able to model closely. This study examined whether the canine groove model of OA represents early OA in humans based on the changes in the lipid species profile in SF. Furthermore, the SF lipidomes of humans and dogs were compared to determine how closely canine lipid species profiles reflect the human lipidome.

METHODS

Lipids were extracted from cell- and cellular debris-free knee SF from nine donors with healthy joints, 17 patients with early and 13 patients with late osteoarthritic changes, and nine dogs with knee OA and healthy contralateral joints. Lipid species were quantified by electrospray ionization tandem mass spectrometry (ESI-MS/MS).

RESULTS

Compared with control canine SF most lipid species were elevated in canine OA SF. Moreover, the lipid species profiles in the canine OA model resembled early OA profiles in humans. The SF lipidomes between dog and human were generally similar, with differences in certain lipid species in the phosphatidylcholine (PC), lysophosphatidylcholine (LPC) and sphingomyelin (SM) classes.

CONCLUSIONS

Our lipidomic analysis demonstrates that SF in the canine OA model closely mimics the early osteoarthritic changes that occur in humans. Further, the canine SF lipidome often reflects normal human lipid metabolism.

[Intentional poisoning of two wives by their husband?]

The authors report on the death of two women who were married to the same man one after the other. Exhumation and toxicological investigation of the first wife, who had died 7 years before, did not produce any conclusive evidence of homicide. With regard to the circumstances of death of the second wife the husband made different statements. According to the result of the chemical and toxicological investigations death was caused by acute intoxication with the beta-blocker metoprolol. The man was found guilty of killing on request (which is a criminal offence in Germany) by administering the beta-blocker metoprolol through a transnasal gastric tube.

[Cause and manner of death in the autopsy material of the Institute of Forensic Medicine, Justus Liebig University Giessen, from 2002-2006]

A retrospective analysis of the autopsy material of the Institute of Forensic Medicine, Justus Liebig University Giessen, in the years 2002 to 2006 showed that the Giessen material is similar to that of comparable studies but contains a relatively large share of lethal intoxications and cases with a concrete suspicion of poisoning in which the cause of death was not definitely clarified by further investigations. On the basis of our own results it is demonstrated that additional chemical, toxicological and histological examinations are helpful to determine initially unclear causes of death. In view of the already very low autopsy rates in Germany it is strange that more detailed diagnostic measures are often omitted.

[Forensic assessment of suspected medical malpractice and outcome of preliminary proceedings against medical practitioners]

In a retrospective study, all autopsies performed at the Institute of Forensic Medicine of the Justus Liebig University of Giessen between 1968 and 2007 for suspected medical malpractice with fatal outcome were evaluated and analysed with regard to the reason for initiating preliminary investigations and the medical specialties involved. In 109 cases, the prosecution files could be inspected as to the outcome of the proceedings. As there are hardly any comparable studies in the German-speaking countries, the data were compared with the results of two older studies. In many cases, medical malpractice could be excluded directly at the end of the post-mortem examination. Most of the charges were dropped according to Section 170 subs. 2 Code of Criminal Procedure.

The role of histopathology in forensic practice: an overview

The role of forensic histopathology in routine practice is to establish the cause of death in particular cases. This is achieved on the basis of microscopic analysis of representative cell and tissue samples taken from the major internal organs and from abnormal findings made at autopsy. A prerequisite of this is adherence to the quality standards set out for conventional histological/cytological staining and enzyme histochemical and immunohistochemical methods. The interpretation of histological findings is performed by taking into account macroscopic autopsy findings and information on previous history. Histological analysis may prompt postmortem biochemical and chemical-toxicological investigations. The results of histological analysis need to be classified by experts in the context of the available information and the need to withstand the scrutiny of other experts.

Cardiomyopathies--misdiagnosed as Sudden Infant Death Syndrome (SIDS)

Cardiomyopathies are an important and heterogenous group of diseases. With the identification of several new disease entities over the past decade, advances in diagnosis and precise causation, some disease definitions have become outdated. The past decade has witnessed a rapid evolution of molecular genetics in cardiology, e.g. myocardial diseases (Hypertrophic cardiomyopathy-HCM, Arrhythmogenic right ventricular cardiomyopathy-ARVCM) and channelopathies (Long QT syndrome-LQTS, Brugada syndrome-BrS, Catecholaminergic Polymorphic Ventricular Tachycardia-CPVT and Short QT syndrome-SQTS) as diseases predisposing to potentially lethal ventricular tachyarrhythmias. Beside the detection of mutations in several genes, histological and immunohistochemical findings can point to a cardiomyopathy as underlying disease. Therefore, previous microscopical investigations of different parts of the myocardium can help to select those cases of suspected Sudden Infant Death Syndrome (SIDS), where a search for genetic mutations can lead to a diagnosis explaining the sudden and unexpected death.

Spinal epidural haematoma after blunt trauma to the neck and hyperflection of the cervical spine

Spinal epidural haematomas (sEDH) can be regarded as rare events, in principle a spontaneous and a traumatic aetiology can be distinguished. Spontaneous spinal epidural haematomas can arise, e.g. from vascular malformations, coagulopathies, etc. On the other hand, traumatic sEDH are related to, e.g. spinal trauma or intraoperative vascular injuries. With regard to clinical significance, spinal epidural haematomas accompanied by transient mild neurological symptoms up to lethal outcomes have been observed. We report on a 53-year-old male alcoholic who was found in the kitchen of his asylum in a grotesquely fixed body position, with his head and cervical spine in a maximum anteflected position. A general practitioner had ruled for a non-natural manner of death due to "broken neck" and alcohol intoxication, therefore, the prosecution authorities called for a medicolegal autopsy. At autopsy, paravertebral soft tissue haemorrhage in between the shoulder blades was disclosed. Furthermore, a spinal epidural haematoma, extending from the foramen magnum down to the middle portion of the thoracic spine was found. No fractures of vertebrae nor lesions of spine ligaments or bleedings of intervertebral discs were found. Blood alcohol concentration was determined 1.92 g/l and urine alcohol concentration was 1.76 g/l. Further morphological findings were cerebral oedema and cardiac hypertrophy; the urinary bladder was found filled to bursting. Neuropathological investigations confirmed the presence of the spinal epidural haematoma and assigned lethal significance to this finding. There were no histological signs of axonal injury. Reconstruction revealed that when sitting on a chair in a drunk condition, the individual's upper part of the body had fallen backwards in the corner and subsequently got stuck with maximum anteflection of the head and cervical spine, causing rupture of vessels and spinal epidural haematoma. Acute respiratory failure caused by impairment of the phrenic nerve following spinal epidural haematoma with potential synergism of alcohol intoxication was ascertained as the cause of death.

Lethal enterovirus-induced myocarditis and pancreatitis in a 4-month-old boy

After inconspicuous pregnancy and birth, a 16-year-old mother presented her male baby 5 days later with severe diarrhoea and vomiting. During the following weeks, the child temporarily showed hypotension, hypothermia and increased body temperature, bradyarrythmia with apnoea, continuing diarrhoea, sometimes vomiting and developed signs of pancreatic insufficiency. Due to increasing loss of weight and obviously severe dystrophia, parenteral nutrition had to be initiated. All clinical investigations revealed no underlying disease. Numerous biopsies, mainly from the gastrointestinal tract were taken, but no relevant pathological findings were disclosed. The baby was found lifeless by his mother, 4 months after birth. According to the death certificate, the physicians regarded the lethal outcome as a case of sudden infant death syndrome (SIDS). Histological and immunohistochemical investigations of organ samples revealed signs of myocarditis, pancreatitis and focal pneumonia. Molecularpathological techniques were used to detect enterovirus RNA from tissue samples from the myocardium, liver and pancreas. Enteroviral myocarditis with concomitant pancreatitis was determined as cause of death.

Heroin-associated nephropathy

Since the first reports in the late 1960s and early 1970s there have been numerous studies describing the clinical and pathological features of renal diseases associated with chronic parenteral abuse of heroin, cocaine, morphine, amphetamine, and other narcotic and hallucinogenic drugs, including several adulterants. The past 35 years have witnessed an explosive growth in illicit drug use in many parts of the world. Meanwhile, drug addict nephropathy constitutes an important cause of end-stage renal disease. The term heroin-associated nephropathy' includes different morphological findings following chronic drug abuse. Up to now it still remains ambiguous as to whether or not heroin/morphine itself, adulterants, other diseases like hepatitis B and C infection, or HIV, lead to a spectrum of morphologically described heroin-associated' findings in the kidneys. As a measure of prevention it appears that the purity of heroin plays an important role.

Two simultaneous suicidal gunshots to the head with robbed police guns

The suicidal infliction of two gunshot wounds to the head represents a critical issue for medicolegal investigation. In principle, simultaneous infliction with two firearms or third parties' involvement, i.e. two consecutive gunshots, have to be considered. We report for the first time on a case of suicidal infliction of two simultaneous gunshots to the head (oral, temporal) with Action 4 expanding ammunition. A male had robbed two service guns and committed suicide thereafter under the influence of high-dose alcohol and cocaine. Interestingly, Action 4 ammunition had been used, leading to an uncommon gunshot wound morphology and extensive backspatter. At the scene, these findings caused confusion; moreover, the number of gunshot wounds was unclear, until autopsy revealed two gunshot wounds to the head, which had obviously been inflicted simultaneously. Expanding ammunition like QD-PEP and Action 4, used by several German federal state police forces, can cause an atypical gunshot wound morphology, most probably due to its peculiar deformation behaviour. Investigators should be careful when interpreting gunshot wound morphology at the scene after usage of such expanding ammunition. With regard to reconstruction in cases of two gunshot wounds to the head and two guns at the scene, two simultaneous gunshots should be taken into consideration.

An unusual occupational accident: fall into a sewage plant tank with lethal outcome

Occupational accidents, often presenting with lethal outcomes, are a rarely reported issue in forensic literature. However, these incidents are part of medicolegal casework with special regard to reconstruction, liabilities and insurance law-related issues, respectively. We report on a lethal occupational accident in a metropolitan sewage plant. When performing routine controls, a technician fell into an overflow sewer and was immediately pulled into a 30 cm diameter drain. Rescue efforts were initiated immediately, but had to be terminated due to gas warning. Rescue teams continued the search, however, the body remained undiscoverable. Forty-eight hours later, the cadaver was found in an adjacent digester tank, from where it was finally rescued. It was concluded, that the body had been transported between the overflow sewer and the digester tank through a 120 m pipeline with several 90 degrees bendings and branch connections with a minimum diameter of 25 cm at the discharge valve. On medicolegal examination, the cadaver showed marked signs of advanced decomposition caused by anaerobic microorganisms in the 37 degrees C biomass environment. Moreover, as a consequence of the passage of the pipeline system, signs of massive trauma (several comminuted and compound fractures) were disclosed at autopsy. To us, this is the first report on a lethal occupational accident in a sewage plant; our observations demonstrate the rapid progress of putrefaction in a warm anaerobic bacterial environment and the massive trauma sustained.

[Medicolegal aspects of witnessed suicide due to gunshot to the head. II. Legal medicine aspects and examination of the firing hand]

The second part of the paper on suicides by gunshots to the head in the presence of witnesses focuses on relevant morphological autopsy findings such as entrance site, signs of close range or contact shots, bullet path etc. and also discusses selected aspects of ascertaining gunshot residues. For the identification of the shooter an integral medicolegal assessment of all the facts including the investigation results and the autopsy findings is essential. However, the morphological findings alone do not allow safe diagnosis, as for example in a homicide the temporal region, which was affected in all our cases, may have been deliberately chosen by the perpetrator as a localization typical of suicide. Thus methods to ascertain gunshot residues on the firing hand (by means of adhesive films and the polyvinyl-alcohol collection method--PVAL) are of great practical importance. In seven cases adhesive films and/or the polyvinyl-alcohol collection method were used. In one case the gunshot residues (GSR) were analysed by means of tape lifts and subsequent scanning electron microscopy (SEM). It was found that especially the combined application of topographical (adhesive tape/PVAL) and cumulative (SEM) methods allowed for the doubtless identification of the shooter, thus usually confirming the suicide. By the example of one case it is demonstrated that without the immediate collection of evidence at the scene objective reconstruction of the event becomes impossible. On the basis of the reported cases recommendations are finally given for a differentiated approach in the medicolegal evaluation of alleged witnessed suicide by gunshot (to the head).

[Medicolegal aspects of witnessed suicide due to gunshot to the head. Part 1: Circumstances and psychopathology]

In the USA the frequency of witnessed suicide, i.e. suicide committed in the presence of at least one further individual, is reported to range between 5 and 15%. As up to now no detailed analysis of this special issue has been given in the medicolegal literature, this article presents and discusses a number of cases including 8 males and 1 female (age 19-58 years, mean 41.2 years) who had all committed suicide by inflicting a gunshot to the head. In 3 cases post-mortem blood alcohol concentrations of 1.73, 1.88 and 2.23 g/kg respectively were observed. Toxicological tests produced negative results. 5 cases had a medical history of psychiatric disorder with endogenous depression in 3, chronic alcohol abuse and drug abuse with concomitant psychosis in one case each. As far as the motives were known, domestic arguments were of prevailing importance. With one exception the suicides were committed at home. In 6 cases one witness was present, in 2 cases 2 individuals and in one case 22 persons witnessed the suicide. The reported cases are discussed in comparison with the psychiatric-psychological classification according to McDowell et al. with the aim to provide a solid and comprehensive medicolegal method to distinguish between homicide and suicide. Furthermore aspects of psychiatric sequelae and psychological support of the witnesses, which are also of importance for the forensic pathologist called to the scene, are discussed.