It is all about the insects: a retrospective on 20 years of forensic entomology highlights the importance of insects in legal investigations.

This study highlights the importance of insect evidence by evaluating 949 insect-associated cases, including 139 entomological reports, from 2001 to 2019 at the Institute of Legal Medicine Frankfurt/Germany. With a high number of cases in the summer months and a low number in the colder season, 78.5% of the bodies were found indoors, regardless of year or month. In more than 80% of the cases, where PMI information was available (n = 704), the presumed PMI ranged from 1 to 21 days, a period during which entomological evidence can provide a day-specific estimate of PMImin. In cases where insects have been identified to species level (n = 279), most bodies were infested by one or two species with a maximum of 10 different species. Overall, a total of 55 insect species were found. Information on biology, activity and distribution of the most abundant taxa is given and applied for 5 case histories estimating different PMImins of up to over 6 months. Despite proved importance and scientific development of forensic entomology, insects are still rarely considered as a tool in forensic case work. The main reasons are a lack of awareness and (too) late involvement of a forensic entomologist. Our work shows that forensic entomology is an independent discipline that requires specialist expertise.

hFRUIT: An optimized agent for optical clearing of DiI-stained adult human brain tissue.

Here, we describe a new immersion-based clearing method suitable for optical clearing of thick adult human brain samples while preserving its lipids and lipophilic labels such as 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI). This clearing procedure is simple, easy to implement, and allowed for clearing of 5 mm thick human brain tissue samples within 12 days. Furthermore, we show for the first time the advantageous effect of the Periodate-Lysine-Paraformaldehyde (PLP) fixation as compared to the more commonly used 4% paraformaldehyde (PFA) on clearing performance.

Automatic Segmentation of Human Cortical Layer-Complexes and Architectural Areas Using Ex vivo Diffusion MRI and Its Validation.

Recently, several magnetic resonance imaging contrast mechanisms have been shown to distinguish cortical substructure corresponding to selected cortical layers. Here, we investigate cortical layer and area differentiation by automatized unsupervised clustering of high-resolution diffusion MRI data. Several groups of adjacent layers could be distinguished in human primary motor and premotor cortex. We then used the signature of diffusion MRI signals along cortical depth as a criterion to detect area boundaries and find borders at which the signature changes abruptly. We validate our clustering results by histological analysis of the same tissue. These results confirm earlier studies which show that diffusion MRI can probe layer-specific intracortical fiber organization and, moreover, suggests that it contains enough information to automatically classify architecturally distinct cortical areas. We discuss the strengths and weaknesses of the automatic clustering approach and its appeal for MR-based cortical histology.

Histological validation of high-resolution DTI in human post mortem tissue.

Diffusion tensor imaging (DTI) is amongst the simplest mathematical models available for diffusion magnetic resonance imaging, yet still by far the most used one. Despite the success of DTI as an imaging tool for white matter fibers, its anatomical underpinnings on a microstructural basis remain unclear. In this study, we used 65 myelin-stained sections of human premotor cortex to validate modeled fiber orientations and oft used microstructure-sensitive scalar measures of DTI on the level of individual voxels. We performed this validation on high spatial resolution diffusion MRI acquisitions investigating both white and gray matter. We found a very good agreement between DTI and myelin orientations with the majority of voxels showing angular differences less than 10°. The agreement was strongest in white matter, particularly in unidirectional fiber pathways. In gray matter, the agreement was good in the deeper layers highlighting radial fiber directions even at lower fractional anisotropy (FA) compared to white matter. This result has potentially important implications for tractography algorithms applied to high resolution diffusion MRI data if the aim is to move across the gray/white matter boundary. We found strong relationships between myelin microstructure and DTI-based microstructure-sensitive measures. High FA values were linked to high myelin density and a sharply tuned histological orientation profile. Conversely, high values of mean diffusivity (MD) were linked to bimodal or diffuse orientation distributions and low myelin density. At high spatial resolution, DTI-based measures can be highly sensitive to white and gray matter microstructure despite being relatively unspecific to concrete microarchitectural aspects.

MIF Receptor CD74 is Restricted to Microglia/Macrophages, Associated with a M1-Polarized Immune Milieu and Prolonged Patient Survival in Gliomas.

The macrophage migration inhibitory factor (MIF) receptor CD74 is overexpressed in various neoplasms, mainly in hematologic tumors, and currently investigated in clinical studies. CD74 is quickly internalized and recycles after antibody binding, therefore it constitutes an attractive target for antibody-based treatment strategies. CD74 has been further described as one of the most up-regulated molecules in human glioblastomas. To assess the potential relevance for anti-CD74 treatment, we determined the cellular source and clinicopathologic relevance of CD74 expression in human gliomas by immunohistochemistry, immunofluorescence, immunoblotting, cell sorting analysis and quantitative polymerase chain reaction (qPCR). Furthermore, we fractionated glioblastoma cells and glioma-associated microglia/macrophages (GAMs) from primary tumors and compared CD74 expression in cellular fractions with whole tumor lysates. Our results show that CD74 is restricted to GAMs in vivo, while being absent in tumor cells, the latter strongly expressing its ligand MIF. Most interestingly, a higher amount of CD74-positive GAMs was associated with beneficial patient survival constituting an independent prognostic parameter and with an anti-tumoral M1 polarization. In summary, CD74 expression in human gliomas is restricted to GAMs and positively associated with patient survival. In conclusion, CD74 represents a positive prognostic marker most probably because of its association with an M1-polarized immune milieu in high-grade gliomas.

Cardiac channelopathy causing sudden death as revealed by molecular autopsy.

BACKGROUND: Mutations in cardiac ion channel genes have been identified to cause sudden unexplained deaths (SUD), and polymorphisms have also been suggested to be risk factors. Therefore, postmortem genetic testing has become an important tool in elucidating the cause of death. METHODS AND RESULTS: In a sudden death case, a LQT-3-associated mutation (Il768V) in the cardiac sodium channel gene SCN5A was detected beside the common polymorphism H558R which is known to mitigate the effect of mutations in the gene. Both sequence variations were heterozygous. Large number of intervening base pairs make it impossible to identify whether they were located in cis or trans. Functional consequences of both variants were characterized after expressing different cRNAs in Xenopus oocytes by voltage clamp measurements. Western blot analysis indicates that the cis configuration of both variants may lead to a null allele. Since the woman had received an injection of Ultracain®, the potential effect of this drug was tested. In a trans configuration of both variants, the mutant channel exhibited an increase susceptibility of at least 10% for blocking with the drug articaine. Another novel finding is that the midpoint of activation in the case of the mutant channel is leftward shifted of at least -10 mV. CONCLUSION: The results of the study suggest that postmortem molecular screening is an important tool to elucidate the cause of SUD and that the administration of a drug and a functional interaction between polymorphisms and ion channel mutations may trigger the risk for sudden death.

Anthropometrical differences between suicide and other non-natural death circumstances: an autopsy study.

BACKGROUND: In international epidemiological studies, associations between suicides and body height, or body mass index (BMI) were found. Because of the recently growing number of suicides in Germany, a closer look on different anthropometric measures of suicide victims autopsied at the Institute of Forensic Medicine of the Goethe-University in Frankfurt/Main, Germany, was taken. METHOD: A retrospective analysis of 1,271 non-natural death cases autopsied between 2006 and 2010 was performed. A total of 566 other than suicide (control group) and 245 suicide cases (study group) with a given body height and weight aged between 18 and 96 years were examined. RESULTS: Body mass indices of the 18-59-year-old male and 60-79-year-old female suicide victims were significantly lower. Old-aged women who committed suicide exhibited beside a significant lower body mass a significantly slender body shape measured as smaller pelvic circumference, waist circumference, and waist-to-tallness ratio. Self-poisoning was by far the leading suicide method in both genders. The victims of the suicide method hanging were the youngest on average, and this method was most common in the male underweight and female lightly normal weight BMI categories, whereas old, overweight, and obese men killed themselves predominantly with firearms. CONCLUSION: The analysis showed that body measures of suicide cases in comparison to other non-natural death circumstance cases differ. For criminal procedural reasons, all suicide cases should be autopsied. But high autopsy rates are also needed for scientific research and to ensure a high level of patient safety.

Histological validation of DW-MRI tractography in human postmortem tissue.

Despite several previous attempts, histological validation of diffusion-weighted magnetic resonance imaging (DW-MRI)-based tractography as true axonal fiber pathways remains difficult. In the present study, we establish a method to compare histological and tractography data precisely enough for statements on the level of single tractography pathways. To this end, we used carbocyanine dyes to trace connections in human postmortem tissue and aligned them to high-resolution DW-MRI of the same tissue processed within the diffusion tensor imaging (DTI) formalism. We provide robust definitions of sensitivity (true positives) and specificity (true negatives) for DTI tractography and characterize tractography paths in terms of receiver operating characteristics. With sensitivity and specificity rates of approximately 80%, we could show a clear correspondence between histological and inferred tracts. Furthermore, we investigated the effect of fractional anisotropy (FA) thresholds for the tractography and identified FA values between 0.02 and 0.08 as optimal in our study. Last, we validated the course of entire tractography curves to move beyond correctness determination based on pairs of single points on a tract. Thus, histological techniques, in conjunction with alignment and processing tools, may serve as an important validation method of DW-MRI on the level of inferred tractography projections between brain areas.

Scalar localization by computed tomography of cochlear implant electrode carriers designed for deep insertion.

OBJECTIVES: This study aimed to evaluate the possibility of predicting radiologically the scalar localization of a 31.5-mm-long, free-fitting electrode carrier for cochlear implantation, using conventional planar computed tomography. STUDY DESIGN: A cross-sectional human temporal bone study was conducted. SETTING: Twenty human temporal bones were acquired postmortem and implanted with 31.5-mm-long electrode carriers. Ten of these were implanted into the scala tympani using the round window approach, whereas the other 10 electrodes were inserted into the scala vestibuli by cochleostomy. Computed tomography was then performed, and 2 experienced blinded radiologists evaluated the intracochlear position of the array. MAIN OUTCOME MEASURE: The estimated position of the electrode carrier was described using a 5-point scale. After sectioning and histologic investigation, the results of the radiologic and histologic investigations were compared. RESULTS: In 17 of 20 cases, it was possible to estimate the correct position of the electrode carrier within the basal turn of the cochlea by means of computed tomography. As the insertion angles widened beyond 360 degrees, it became increasing difficult for the radiologists to correctly determine the position of the electrode carrier. CONCLUSION: The comparison of our temporal bone experiment results with the computed tomography results revealed the difficulty of assessing the correct position of intracochlear electrodes. Scalar localization of deeply inserted electrode carriers cannot be precisely determined by means of computed tomography.

[Reform of forensic autopsy in the German Code of Criminal Procedure]. / Die dritte Anfrage: Zur Reform der gerichtlichen Leichenöffnung in der Strafprozessordnung.

The Federal Ministry of Justice has presented another proposal to rephrase the wording of Section 87 of the German Code of Criminal Procedure (StPO). The new version of Section 87 StPO is to be rejected as it would lead to a loss of institutional and professional standards. The bill is clearly influenced by a tendency towards privatisation for the benefit of a small group of specialists in forensic medicine mostly organised in limited liability companies and thus at the expense of institutes of legal medicine affiliated to universities or physicians working in the forensic service of regional courts. In the long run, this reform would not only jeopardize medicolegal research and teaching but also medical education and specialist medical training. For future severe negative consequences would have to be expected on the rule of law and legal certainty.

[Medical and legal aspects of genital mutilation and circumcision. Part II: Male circumcision]. / Medizinische und rechtliche Aspekte der Genitalverstümmelung bzw. Beschneidung. Tell II: Die rituelle Zirkumzision.

In the last few years, male circumcision has become the subject of controversial discussion. On the one hand, medical and hygienic arguments, ideology, freedom of religion, cultural identity and social adequacy are claimed by those supporting male circumcision. On the other hand, the justification of this practice also has to be critically scrutinized just as the question whether the parents have the right to consent to the operation. Today, opinions range from those who claim that religion and culture alone justify the practice to those who consider circumcision of minors unable to give their consent as bodily injury subject to punishment. In contrast to female genital mutilation, most positions do not postulate that circumcision violates morality. If the person concerned is able to give his consent, freedom of religion may also justify circumcision after weighing its pros and cons as well as its risks and potential side effects.

[Medical and legal aspects of genital mutilation and circumcision part I: female genital mutilation (FGM)]. / Medizinische und Rechtliche Aspekte der Genitalverstiimmelung bzw. Beschneidung Teil I: Weibliche Genitalversttimmelung.

Female genital mutilation (FGM) is considered to be against the law and against morality not only in Western countries, although a woman of age and able to consent may sometimes think differently. The procedure may have serious physical and emotional consequences for the girl or woman. Nevertheless there are attempts to justify the procedure with medical and hygienic pseudoarguments, ideology, freedom of religion, cultural identity and social adequacy. Outside the Western world, some people claim that religion and culture alone justify the practice. In Germany, parents can lose the right to determine the residence of their daughter, if she is faced with the risk of genital mutilation in order to prevent that the child or girl is taken to her home country. Genital mutilation as a gender-specific threat is recognized as a reason to grant asylum or prevent deportation. Proposals to make genital mutilation a separate punishable offence are presently discussed by the legislator.

[Reform of forensic autopsy in the German Code of Criminal Procedure]. / Zur Reform der gerichtlichen Leichenöffnung in der Strafprozessordnung.

The German Federal Ministry of Justice has presented a proposal to amend Section 87 subs. 2 of the German Code of Criminal Procedure (StPO). In the reasons for the bill, the priority of the institutional forensic medicine is emphasized. While parts of the revised version are appreciated, some changes are considered necessary in order to take the special features of the German states into account.

Practical experience in post-mortem tissue donation in consideration of the European tissue law.

In consequence of the European guidelines of safety and quality standards for the donation, retrieval, storing and distribution of human tissues and cells the purpose of tissue transplantation was implemented into German legislation in May 2007. The law came into effect on August 1st 2007 considering of the European rules. The Institutes for Legal Medicine of the University of Frankfurt/Main and the University Medical Center Hamburg-Eppendorf developed a model for tissue retrieval. The Institute of Legal Medicine (I.f.R.) at the University Medical Center Hamburg cooperates with the German Institute of Cell and Tissue Replacement (Deutsches Institut für Zell--und Gewebeersatz DIZG). Potential post-mortem tissue donors (PMTD) among the deceased are selected by standardized sets of defined criteria. The procedure is guided by the intended exclusion criteria of the tissue regulation draft (German Transplant Law TPG GewV) in accordance with the European Guideline (2006/17/EC). Following the identification of the donor and subsequent removal of tissue, the retrieved samples were sent to the DIZG, a non-profit tissue bank according to the tissue regulation. Here the final processing into transplantable tissue grafts takes place, which then results in the allocation of tissue to hospitals in Germany and other European countries. The Center of Legal Medicine at the Johann Wolfgang Goethe-University Medical Center Frankfurt/Main cooperates since 2000 with Tutogen, a pharmaceutical company. Harvesting of musculoskeletal tissues follows corresponding regulations. To verify the outcome of PMTD at the I.f.R. Hamburg, two-statistic analysis over 12 and 4 months have been implemented. Our results have shown an increasing number of potential appropriate PMTD within the second inquiry interval but a relatively small and unvaryingly rate of successful post-mortem tissue retrievals similar to the first examination period. Thus, the aim of the model developed by the I.f.R. is to increase the number of PMTD retrievals and, furthermore, to avoid any conflict of interest between organ and tissue donation.

Cardiac gene defects can cause sudden cardiac death in young people.

BACKGROUND: In Europe, sudden cardiac death (SCD) is one of the most common causes of death. Although sudden cardiac death usually happens in older people, 5% to 10% of the affected individuals are young and apparently healthy. Sudden death in infants, children, and young adults is relatively rare, with an incidence of 1 to 5 per 100 000 persons per year. Nonetheless, up to 7000 asymptomatic children die in the USA each year, almost half of them without any warning signs or symptoms. METHOD: Selective literature review. RESULTS: Although structural cardiovascular abnormalities explain most cases of sudden cardiac death in young people, the cause of death remains unexplained after autopsy in 10% to 30% of cases. Potentially lethal ion channel disorders (channelopathies) such as the long QT syndromes (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), and the Brugada syndrome (BrS) may account for at least one-third of these unexplained cases. Most of these diseases are hereditary with autosomal-dominant transmission, i.e., there is a 50% chance that the children of affected individuals will be affected themselves. CONCLUSIONS: Post-mortem genetic screening for sequence variations in cardiac ion channel genes has become an important forensic tool for elucidating the cause of sudden cardiac death. Moreover, it allows the identification of other family members bearing the previously undiagnosed gene defect, who can then undergo a cardiological evaluation if indicated by their clinical history.

[External and internal post mortem examination according to the german code of criminal procedure (StPO)--review of section 87 StPO with special emphasis on the forensic autopsy]. / Die äussere und innere Leichenschau nach der deutschen Strafprozessordnung--Analyse des 87 StPO unter besonderer Berücksichtigung der gerichtlichen Leichenöffnung.

Section 87 subs. 2 of the German Code of Criminal Procedure stipulates that a forensic or court-ordered autopsy shall be performed by two physicians. One of them must be a "forensic medical officer" (in German "Gerichtsarzt") or the head of a public forensic or pathology institute or a physician of such an institute entrusted with this task and having specialist knowledge of forensic medicine. Recently, it has been suggested to amend Section 87 subs. 2 StPO to the effect that self-employed specialists in forensic medicine can also be entrusted with court-ordered autopsies. The authors object to such privatization of forensic autopsies for legal and factual reasons and recommend to keep the present regulation according to which one of the physicians conducting the autopsy is not only required to have the necessary professional qualification, but must also hold a public position as defined in the law.

Molecular study of time dependent changes in DNA stability in soil buried skeletal residues.

In the past years, many publications about identification and sex-determination of dry human bones by means of DNA analysis have been published. However, few studies exist that investigate the potential use of DNA technique to determine the postmortem interval (PMI). In the present study we analyzed the rate of increasingly smaller fragments of chromosomal DNA and PMI. We examined DNA degradation in human bones with postmortem intervals ranging between 1 and more than 200 years that had been kept under comparable conditions concerning weather and soil. Following bone separation into the three different zones of interest of inner/middle/outer segments the quantity of total DNA was determined in each region. Subsequently, the degree of DNA fragmentation was estimated by searching for PCR products of defined size (150, 507 and 763 bp) with primers of the human-specific multicopy beta-actin-gene. Concerning DNA quantity we detected a significant correlation between the zone of interest and the amount of DNA. However, there was no correlation between the amount of DNA and PMI. In contrast to this, analyzing DNA using PCR showed a significant inverse correlation between fragment length and PMI. Thus, postmortem DNA degradation into increasingly smaller fragments reveals a time-dependent process. It has the potential to be used as a predictor of PMI in human bone findings, provided that environmental conditions are known.

High-resolution diffusion tensor imaging and tractography of the human optic chiasm at 9.4 T.

The optic chiasm with its complex fiber micro-structure is a challenge for diffusion tensor models and tractography methods. Likewise, it is an ideal candidate for evaluation of diffusion tensor imaging tractography approaches in resolving inter-regional connectivity because the macroscopic connectivity of the optic chiasm is well known. Here, high-resolution (156 microm in-plane) diffusion tensor imaging of the human optic chiasm was performed ex vivo at ultra-high field (9.4 T). Estimated diffusion tensors at this high resolution were able to capture complex fiber configurations such as sharp curves, and convergence and divergence of tracts, but were unable to resolve directions at sites of crossing fibers. Despite the complex microstructure of the fiber paths through the optic chiasm, all known connections could be tracked by a line propagation algorithm. However, fibers crossing from the optic nerve to the contralateral tract were heavily underrepresented, whereas ipsilateral nerve-to-tract connections, as well as tract-to-tract connections, were overrepresented, and erroneous nerve-to-nerve connections were tracked. The effects of spatial resolution and the varying degrees of partial volume averaging of complex fiber architecture on the performance of these methods could be investigated. Errors made by the tractography algorithm at high resolution were shown to increase at lower resolutions closer to those used in vivo. This study shows that increases in resolution, made possible by higher field strengths, improve the accuracy of DTI-based tractography. More generally, post-mortem investigation of fixed tissue samples with diffusion imaging at high field strengths is important in the evaluation of MR-based diffusion models and tractography algorithms.