The history of forensic entomology in German-speaking countries

Megnin's book "La fauna des cadaveres" published in 1894 in France is generally accepted as a mile-stone in forensic entomology. It is hardly known that at the same time this topic was likewise explored in the German-speaking countries. Even PMI estimation based on developmental data of blowflies was performed. After a more descriptive period in the first half of the 20th century the complexity and variability of insects' biological behavior were detected and formally investigated. Improved technical facilities, enhanced comprehension of scientific studies and multidisciplinary cooperation, enabled rapid progress in forensic entomology during the last decades. With the European Association for Forensic Entomology founded in 2002 the frame work for a high standard of competency at an international level was constituted.

Post-mortem diagnosis and age estimation of infants' fractures

Detection and dating of infants' fractures plays an important role in the diagnosis of the battered child syndrome. Under this aspect three cases of infants with multiple fractures of different ages due to child abuse were evaluated post-mortem. Radiological findings were compared with the autopsy results, followed by contact radiography and histopathological assessment. Out of a total of 44 osseous lesions, 27 fractures were diagnosed by post-mortem skeletal survey, additionally 5 recent rib fractures were suspected, 4 of which were confirmed histologically and all were located paravertebrally. The fractures not detected radiologically were mostly recent rib fractures diagnosed or suspected at autopsy or by contact radiography and confirmed histologically. The histological investigation allowed a more precise dating of the fractures, particularly with reference to the early stages of fracture healing. Microscopic signs of fracture healing processes, such as periosteal thickening, osteoid production and calcification of soft callus tissue, can be detected earlier and quantified more accurately. In advanced stages of healing the osseous apposition rate can be measured semiquantitatively up to a certain extent. A scheme involving a careful external investigation, skeletal survey, autopsy, contact radiography and histology has been proven useful for diagnosing and dating infants' fractures.

Use of PCR-RFLP for differentiation of calliphorid larvae (Diptera, Calliphoridae) on human corpses

Blowfly larvae found on human corpses are important for the estimation of the postmortem interval (PMI) and other questions of forensic relevance. Some of these species are difficult to differentiate morphologically, therefore a molecular method was elaborated for species identification. Specific fragments of the COI and COII region of the mitochondrial DNA (mtDNA) were amplified followed by digestion with different restriction enzymes. Using a 1.3 kb fragment, identification of Lucilia sericata, Calliphora vicina and Calliphora vomitoria was possible by digestion with only one restriction enzyme using either DraI or HinfI. Furthermore, we sequenced 349 bp (a part of the COI and COII regions) from the same three species and found 34 nucleotide distinctions between C. vicina and L. sericata, 30 between C. vomitoria and L. sericata and 15 between the two Calliphora species. These results aid in quick identification of species used for estimation of PMI.

Larder beetles (Coleoptera, Dermestidae) as an accelerating factor for decomposition of a human corpse

Larder beetles are known to feed directly upon decomposing carrion, with a preference for dried carrion. Under optimal environmental conditions (dry and warm), they can appear in large numbers. In our case, the mummified corpse of a human male was nearly skeletonized in less than 5 months in his apartment with windows closed and a room temperature between 25 degrees C (near the radiator) and 19.4 degrees C (near the body). There were very few empty fly pupae in the apartment, but a lot of adult hide beetles, their larvae and larval cast skins (exuviae) (Dermestes maculatus DEG.) belonging to the family of the larder beetles (Dermestidae). The beetles skeletonized the human corpse in such a short time because of ideal conditions for them in the apartment (dry and warm) making the body an optimal feeding ground because of his mummification.

[Concealed and simulated trauma fatalities(II)]

A careful investigation of fatal accidents is required due to the relevant financial consequences for the insured as well as for the insurance company. An evaluation of post-mortem cases handled by our institute from 1988 to 1998 showed that 16% of all fatal accidents were not initially classified as such; it was only possible to determine the cause by post-mortem and criminal investigation. The frequency of a relevant alcoholization varied with different types of accidents. Furthermore, of all fatal accidents, 3% were revealed to be deceptive. Those 42 cases in total, presenting themselves as fatal accidents at first glance, were later determined either to be natural deaths (n = 27), homicide (n = 11) or suicide (n = 4). In addition to this, autopsies showed 83 cases of death to be sequelae to accidents. Particularly in cases of a victim plunging out of the window or into water, it can be difficult to make the distinction between natural death--e.g. as a reason for falling--and suicide or homicide. Further difficulties can result from interpretations of the findings in cases of putrefaction, mauling by animals, defects caused by burning or severely deformed corpses. In these cases, the importance of patho-morphological findings from the autopsy must be emphasized. Indirect sequelae of accidents may be pulmonary embolism or pneumonia. The cause of death has to be classified as accidental if the chain of events is of traumatic origin. Mistakes can be avoided if the medical history is taken conscientiously. If no facts are available, the cause of death should be certificated as undetermined. Our evaluation only included autopsy cases from our institute. The concealed fatal accidents which were incorrectly certified as natural deaths or the cases dismissed by the police and the public prosecutor without performing an autopsy were not evaluated.

Tumor necrosis factor receptor-associated factor 1 is overexpressed in Reed-Sternberg cells of Hodgkin's disease and Epstein-Barr virus-transformed lymphoid cells

The tumor necrosis factor (TNF) receptor-associated factor 1 (TRAF1) is a member of the recently defined TRAF family. It takes part in the signal transduction of the TNF receptor 2 (TNFR2), the lymphotoxin-beta receptor (LT-betaR), CD40, CD30, and LMP1; is induced by LMP1 in vitro; and protects lymphoid cells from apoptosis. To identify the cells in which TRAF1 is active in vivo, we studied TRAF1 transcripts in normal lymphoid tissue, in Epstein-Barr virus (EBV)-induced lymphoproliferations, and in malignant lymphomas with special reference to those that overexpress the cytokine receptor CD30 and CD40 of the TNF receptor family at the single-cell level using a radioactive in situ hybridization. In normal lymphoid tissue, TRAF1 message proved to be absent from all resting B and T cells as well as from macrophages and accessory cells (follicular dendritic cells and interdigitating cells) and present in few perifollicular and intrafollicular lymphoid blasts. In contrast, there was a high and consistent TRAF1 overexpression in EBV-induced lymphoproliferations and Hodgkin's disease. Nearly all non-Hodgkin's lymphoma show low or no TRAF1 expression. Only some cases of diffuse large B-cell lymphoma showed a moderate to high TRAF1 signal. Several of the latter cases were EBV+. These data confirm that TRAF1 is an inducible molecule and indicates its deregulation in the mentioned disorders with the potential of a blockage of the apoptotic pathway.

Expression of vascular endothelial growth factor in lymphomas and Castleman's disease

Vascular endothelial growth factor (VEGF) is one of the main angiogenic cytokines in human solid tumours and inhibition of VEGF-induced angiogenesis suppresses tumour growth. Some groups of malignant lymphoma, including peripheral T-cell lymphomas and Hodgkin's disease, are characterized by a conspicuous proliferation of small vessels. To test the hypothesis that VEGF may also be involved in the angiogenesis in lymphomas and other lesions of the lymphoid system, VEGF expression was analysed in tissues, employing in situ hybridization with a 35S-labelled RNA probe specific for this cytokine. Significant expression of VEGF transcripts was observed in Hodgkin's disease and peripheral T-cell lymphomas, particularly of the angioimmunoblastic type. In contrast, expression of this cytokine was minimal or absent in follicle centre lymphoma and chronic lymphocytic leukemia of B-cell type. VEGF was mainly observed in reactive non-lymphoid CD68-negative cells, which probably represent fibroblasts or myofibroblasts. In normal and ulcerated tonsils, VEGF was expressed in the squamous epithelium but only rarely found in the lymphoid tissue. Although infectious mononucleosis tonsils contained high numbers of VEGF-positive cells in the interfollicular zone, expression of this cytokine was not found in Epstein-Barr virus (EBV)-infected cells, as determined by simultaneous in situ hybridization for VEGF and EBV-encoded small nuclear RNAs (EBER). In 5/8 cases of Castleman's disease, germinal centres containing small vessels also showed expression of VEGF, in contrast to normal tonsillar germinal centres which are devoid of both vessels and VEGF transcripts. It is concluded that VEGF may be involved in the induction of the angiogenesis of both peripheral T-cell lymphomas and Hodgkin's disease, but not in low-grade B-cell lymphomas. In contradistinction to solid tumours, in which this cytokine is commonly secreted by the tumour cells themselves, in malignant lymphoma VEGF is not a product of neoplastic cells. Vascularization of germinal centres in Castleman's disease may also be a consequence of abnormal local expression of VEGF.

Frequent expression of interleukin-10 by Epstein-Barr virus-harboring tumor cells of Hodgkin's disease

Tumor cells of Epstein-Barr virus (EBV)-associated Hodgkin's disease (HD) express the viral protein, latent infection membrane protein-1 (LMP1), but evade cytotoxic responses normally directed at this antigen. We tested whether local production of the immunoregulatory interleukins (IL)-4 and -10 may have a role in this process. IL-4 RNA was not detectable in any of the HD cases. By contrast, isotopic in situ hybridization and correlation with the presence of EBV gene products showed significantly higher proportions of cases with IL-10 expressing tumor cells in LMP1-positive (17 of 26, 66%) as compared with LMP1-negative HD cases (six of 37, 16%). Absence of EBV BCRF1 RNA indicated that the transcripts originated from the cellular IL-10 gene. Similarly, an association between IL-10 expression and EBV-infection of tumor cells was found in AIDS-related malignant non-Hodgkin lymphomas (ARL). Very small proportions of EBV-infected cells, mainly blasts, expressed IL-10 in infectious mononucleosis tonsils. Thus, although not entirely exclusive to EBV-positive cases, IL-10 expression is frequently associated with EBV-infection in HD and ARL and appears to be upregulated by EBV, most likely through LMP1. In view of the established inhibitory effects of IL-10 on cell mediated immunity, it is suggested that IL-10 expression may contribute to evasion of LMP1-positive cells from cytotoxicity directed at viral antigens.