Role of forensic pathologists in mass disasters

The forensic pathologist has always had a central role in the identification of the dead in every day practice, in accidents, and in disasters involving hundreds or thousands of victims. This role has changed in recent years, as advances in forensic odontology, genetics and anthropology have improved the chances of identifying victims beyond recognition. According to the Interpol DVI Guide, fingerprints, dental examination and DNA are the primary identifiers, and this has given new emphasis to the role of the forensic pathologist as the leader of a multidisciplinary team of experts in a disaster situation, based on his or her qualifications and the experience gained from doing the same work in the everyday situation of an institute of forensic medicine.     

A novel method of species identification using human muscle-specific beta-enolase

A novel method of species identification using a sensitive sandwich enzyme immunoassay for human muscle-specific beta-enolase was used to analyze bloodstains and skeletal muscle. Human beta-enolase is detectable in human blood at dilutions up to 3 x 10(3) and human muscle extract (0.1 g/ml) at dilutions up to 5 x 10(6) using a sandwich enzyme immunoassay. The cross-reactivities of both blood and skeletal muscle extracts from other species were 0.01 or less. When human skeletal muscle extract was added in a final concentration of 10 mg/ml, the ratio of beta-enolase to total protein in bloodstains was approximately 1000, whereas the addition of skeletal muscle extract of other species resulted in a ratio of less than 10. Application of this method in a practical case proved that human muscle-specific beta-enolase as a marker for species identification is very effective in forensic practice.     

Identification of organ tissue types and skin from forensic samples by microRNA expression analysis

The identification of organ tissues in traces recovered from scenes and objects with regard to violent crimes involving serious injuries can be of considerable relevance in forensic investigations. Molecular genetic approaches are provably superior to histological and immunological assays in characterizing organ tissues, and micro-RNAs (miRNAs), due to their cell type specific expression patterns and stability against degradation, emerged as a promising molecular species for forensic analyses, with a range of tried and tested indicative markers.Thus, herein we present the first miRNA based approach for the forensic identification of organ tissues. Using quantitative PCR employing an empirically derived strategy for data normalization and unbiased statistical decision making, we assessed the differential expression of 15 preselected miRNAs in tissues of brain, kidney, lung, liver, heart muscle, skeletal muscle and skin. We show that not only can miRNA expression profiling be used to reliably differentiate between organ tissues but also that this method, which is compatible with and complementary to forensic DNA analysis, is applicable to realistic forensic samples e.g. mixtures, aged and degraded material as well as traces generated by mock stabbings and experimental shootings at ballistic models.     

Muscidae (Diptera) of forensic importance—an identification key to third instar larvae of the western Palaearctic region and a catalogue of the muscid carrion community

The Muscidae is one of the main dipteran families recognized as important for medico-legal purposes. Although an association of adult flies with decomposing human and animal bodies is documented for about 200 taxa worldwide, cadavers and carrion represents a breeding habitat for considerably fewer species. Species that do colonize dead human bodies can do so under diverse environmental conditions and, under certain circumstances, Muscidae may be the only colonizers of a body. Because of difficulties in identification, many studies have identified immature and/or adult muscids only to the genus or family level. This lack of detailed species-level identifications hinders detailed investigation of their medico-legal usefulness in carrion succession-oriented experiments. Identification to species level of third instars of Muscidae of forensic importance and the utility of larval morphological characters for taxonomic purposes were subjected to an in-depth revision. A combination of characters allowing for the discrimination of third instar muscids from other forensically important dipterans is proposed. An identification key for third instar larvae, which covers the full set of cadaver-colonising species of Muscidae from the western Palaearctic (Europe, North Africa, Middle East), is provided. This key will facilitate more detailed and species-specific knowledge of the occurrence of Muscidae in forensic entomology experiments and real cases. The carrion-visiting Muscidae worldwide are catalogued, and those species breeding in animal carrion and dead human bodies are briefly discussed with regard to their forensic importance.

     

RAPD & FINS (mitochondrial 16s rRNA gene sequence) in analysis of food contamination: detection of food poisoning by Lizard

In poisoning, detection of the nature of causative agent is important for management of trauma and forensic investigation. Most of the methods in clinical toxicology are developed for detection of toxins and poisons. A random amplified polymorphic DNA (RAPD)-based method has been described for detection of species of animal from its morphologically unrecognizable fragments, recovered from food substances, consumption of which caused even death. Pre-mixed RAPD reaction beads and six RAPD primers were used in polymerase chain reaction analysis. Among six RAPD primers used, any one of them was sufficient in resolving this practical forensic situation. To enhance the probability values for matching in the present study of fixing identity of an animal, six set of market available RAPD primers were used. This is the first report of a forensic application of RAPD DNA typing in identification of charred skeleton remnants of Lizard species in food material. Furthermore unique amplicons were generated for different reptilian species, which can be used as species specific markers for species identification in forensic situation, however, no variations among individuals of same species were observed.     

Trauma and identification of victims of suicidal terrorism in Israel

The postmortem examination and identification procedures performed by medical and law enforcement personnel involved in mass disaster management in Israel are reported. The Israel National Police, the Israel Defense Forces, and the L. Greenberg Institute of Forensic Medicine's experts examined 171 victims who died in 21 incidents of suicidal terrorism. The trauma sustained by the victims and perpetrators of suicidal bombings included complete body disruption and explosive, flying missile, and blast injuries. The modus operandi of the perpetrators, reconstructed from the distribution and type of injury of the victims, is discussed. Fifty-five victims perished in open space bombings and 91 inside buses. All perpetrators of these bombings died at the time of the incident regardless of their location. Identification of the victims was achieved using fingerprints, dental records, medical intervention signs, anatomic variation, genetic profile, and personal recognition. Prompt identification of the perpetrators allowed speedy apprehension of the accomplices and prevention of similar attacks. Collaboration between the different forensic, military, and law enforcement teams increased the efficiency of disaster management efforts.     

Post-mortem injuries by a dog: A case report

Despite its unlikely occurrence, post-mortem animal depredation is not unknown to forensic pathologists. In the case at issue, the corpse of a dead woman presented extensive facial wounds, which were then traced back to the dog she owned. A small specimen of injured tissue was subjected to species diagnosis, and came back positive for human and canine antigens, which confirmed the presence of biological material of canine origin on the body. The less than usual post-mortal injury pattern described herein clearly highlights the possibility that animal depredation on a corpse may occur soon after death, and underscores the diagnostic potential posed by commonly available and low expensive testing methods such as serological species diagnosis.     

Oberflächenelektromyographie

Electromyography is a well established method used in different medical disciplines, such as neurology or orthopaedics as well as in sport science. Forensic biomechanical analyses often include reconstruction of various accidents (e.g. work, traffic, violence). Muscle activity influences the kinematics of the human body and the mechanical properties of muscle tissue. It is important to keep these influences in mind when investigating human kinematics or injury mechanisms.Considering two examples in the field of vehicle occupant safety, the basics of electromyography are discussed and further forensic applications presented.     

Inductively coupled plasma – atomic emission spectroscopy (ICP-AES) as a method of species differentiation of bone fragments

During criminal investigations relating to buried human remains, mass graves, or poaching, human and animal bones may be comingled, highly fragmented, or burned. Misidentification of skeletal elements may result in animal bones being sent to forensic laboratories and human bones sent to a zoologist for identification, creating unnecessary work and further investigative problems. To determine the origin of skeletal remains this research will examine the trace element signature in bone from several different species. The animals of interest in this study included beaver, cat, coyote, deer, fisher, fur seal, mouflon, pig, raccoon, and rat. Bone fragments of each species were collected, prepared, and analyzed using inductively coupled plasma – atomic emission spectroscopy (ICP-AES) to measure the concentrations of aluminum, boron, calcium, iron, lead, potassium, magnesium, and sodium. Significant differences were observed between the various experimental elements and feeder types. Carnivores had significantly higher levels of aluminum, iron, potassium, magnesium, and sodium than both herbivores and omnivores. Significantly higher levels of aluminum, potassium, magnesium, and sodium were detected in domestic species. Discriminant analysis of the species showed that it may be possible to distinguish bone fragments by feeder type, species, and domestication status.     

Non-cryogenic forensic tissue preservation in the field: a review

There are many non-cryogenic tissue preservatives that have been employed for human and non-human specimens and in this review we examine their potential for use in field-based forensic operations such as disaster victim identification (DVI). A number of preservatives show promise for short tandem repeat (STR) profiling of human tissue including FTA paper, solid salt, DMSO, ethanol, buffers and proprietary preservatives. Their use will be governed by considerations such as user safety, cost, ease of use and transport.     

The role of the radiologist in the medicolegal procedure after an aviation accident]

The role of radiologic imaging studies in the forensic medical procedure following an airborne disaster is now well established. This report summarizes the experience and the results acquired with a recent air crash, and insists on three suggestions: the necessity of a prepared identification team consisting of specialist in forensic medicine, in forensic odontology and specialist in forensic radiology, and the usefulness of a suitable structure for the study and the storage of the dead bodies, the need for a compilation of radiological informations, notably dental X-Ray examinations for the flying personnel.     

Effects of exercise on the fatty-acid composition of blood and tissue lipids

This article reviews the effects of acute and chronic exercise on the fatty-acid composition of animal and human tissues (plasma, skeletal muscle, heart, adipose tissue, liver, artery and erythrocytes), as reported in 68 studies spanning four decades. The most consistently observed effect has been an increase in the relative amount of unsaturated, especially monounsaturated, non-esterified fatty acids in plasma of both animals and humans after acute exercise. Chronic exercise seems to increase the proportion of polyunsaturated fatty acids and omega6 fatty acids, while decreasing the proportion of monounsaturated fatty acids in animal and human adipose tissue. Additionally, chronic exercise seems to decrease the relative amount of unsaturated fatty acids in liver lipids of animals and humans. There is no consensus regarding the effect of exercise on the fatty-acid composition of lipids in any other tissue. In general, the effects of exercise are independent of nutrition and, regarding skeletal muscle, muscle fibre type.The available literature shows that, in addition to modifying the concentrations of animal and human tissue lipids, exercise also changes their fatty-acid profile. Unfortunately, the available studies are so much divided among exercise models, species and biological samples that a cohesive picture of the plasticity of the fatty-acid pattern of most tissues toward exercise has not emerged. Future studies should focus on determining the fatty-acid profile of separate lipid classes (rather than total lipids) in separate subcellular fractions (rather than whole tissues), examining tissues and organs on which no data are available and exploring the mechanisms of the exercise-induced changes in fatty-acid composition.     

Examination of postmortem animal interference to human remains using cross-species multiplex PCR

Postmortem animal interference may be confused at first sight with injuries of vital origin, thus arousing suspicion of external violence preceding death. A reliable classification of the origin of such doubtful injuries is of crucial importance, a fact that is especially true for the investigation of suspected homicide and/or mammade body mutilation after death. In forensic pathology, the identification of injuries as caused by animals postmortem and the classification of a particular species as responsible for a specific injury pattern under question is usually done by forensic pathologists with vast practical experience and special knowledge of the appearance and morphology of tooth marks of carnivores and rodents, respectively. However, a molecular biological investigation of such wounds could provide genetic evidence that an injury pattern present on a corpse was truly caused postmortem by animal interference and thus support the pathologist's expertise. For this purpose, we developed a panel of small species-specific short-tandem repeat systems (<150 bp) for animals typically involved in postmortem scavenging of human remains, such as dogs and cats as well as wild-living rodents (mice and rats) having possible access to death scenes inside apartments or buildings. A specific and sensitive cross-species multiplex polymerase chain reaction was then established including the species-specific animal markers, thus enabling the genetic identification of wounds caused postmortem by different animals on human remains. This study was presented at the Sixth International Symposium in Advanced Legal Medicine (ISLAM), Hamburg, Germany, September 2006.     

The potential use of Piwi-interacting RNA biomarkers in forensic body fluid identification: A proof-of-principle study

In the forensic community, RNA profiling has been investigated as a potential method to identify body fluids. Several RNA molecules, including messenger RNA (mRNA), microRNA (miRNA) and circular RNA (circRNA), have been explored as biomarkers to distinguish different body fluids and have led to considerable interest in the development of RNA biomarkers for forensic purposes. Piwi-interacting RNA (piRNA), a class of noncoding RNAs, is a potential biomarker for body fluid identification because of its short length (˜24–32 nt) and specific expression pattern in human tissues. In this proof-of-principle study, we examined the expression levels of four carefully selected piRNAs in forensically relevant biological fluids (venous blood, saliva, semen, menstrual blood and vaginal secretions) using TaqMan quantitative real-time polymerase chain reaction (TaqMan qPCR). piR-55521, which was not detectable in saliva, can differentiate semen from other body fluids because it was strongly expressed in semen compared to the remaining three fluids (> 4000-fold change). Furthermore, piR-55521 could be detected in semen samples made from as little as 200 pg of total RNA, and addition of female component had no effect on the detection limit. Furthermore, the expression differences of other piRNAs, piR-61648, piR-43994 and piR-33151, were statistically significant between at least two types of body fluids. Stability tests also indicated that these piRNAs could be effectively detected in dried samples under laboratory and outdoor conditions for at least six months. Although limited to four piRNAs, this study suggests that the expression pattern of piRNAs could be used to identify body fluids, and that piRNA (piR-55521) is specifically expressed in semen. Such findings suggest that additional work could identify other piRNAs that could serve as biomarkers to identify body fluids.     

Validation of mitochondrial DNA sequencing for forensic casework analysis

Two sets of studies were performed to evaluate the forensic utility of sequencing human mitochondrial DNA (mtDNA) derived from various tissues and amplified by the polymerase chain reaction (PCR). Sequencing was performed on a Perkin-Elmer/Applied Biosystems Division (PE/ABD) automated DNA sequencer (model 373A). The first set of experiments included typical validation studies that had previously been conducted on forensic DNA markers, such as: chemical contaminant effects on DNA from blood and semen and the effect of typing DNA extracted from body fluid samples deposited on various substrates. A second set of experiments was performed strictly on human hair shafts. These studies included typing mtDNA from hairs that were: (1) from different body areas, (2) chemically treated, (3) from deceased individuals, and (4) deliberately contaminated with various body fluids. The data confirm that PCR-based mtDNA typing by direct automated sequencing is a valid and reliable means of forensic identification.     

Microbial DNA fingerprinting of human fingerprints: dynamic colonization of fingertip microflora challenges human host inferences for forensic purposes

Human fingertip microflora is transferred to touched objects and may provide forensically relevant information on individual hosts, such as on geographic origins, if endogenous microbial skin species/strains would be retrievable from physical fingerprints and would carry geographically restricted DNA diversity. We tested the suitability of physical fingerprints for revealing human host information, with geographic inference as example, via microbial DNA fingerprinting. We showed that the transient exogenous fingertip microflora is frequently different from the resident endogenous bacteria of the same individuals. In only 54% of the experiments, the DNA analysis of the transient fingertip microflora allowed the detection of defined, but often not the major, elements of the resident microflora. Although we found microbial persistency in certain individuals, time-wise variation of transient and resident microflora within individuals was also observed when resampling fingerprints after 3 weeks. While microbial species differed considerably in their frequency spectrum between fingerprint samples from volunteers in Europe and southern Asia, there was no clear geographic distinction between Staphylococcus strains in a cluster analysis, although bacterial genotypes did not overlap between both continental regions. Our results, though limited in quantity, clearly demonstrate that the dynamic fingerprint microflora challenges human host inferences for forensic purposes including geographic ones. Overall, our results suggest that human fingerprint microflora is too dynamic to allow for forensic marker developments for retrieving human information.     

Detection of bacterial 16S ribosomal RNA genes for forensic identification of vaginal fluid

To preliminarily evaluate the applicability of bacterial DNA as a marker for the forensic identification of vaginal fluid, we developed and performed PCR-based detection of 16S ribosomal RNA genes of Lactobacillus spp. dominating the vagina and of bacterial vaginosis-related bacteria from DNA extracted from body fluids and stains. As a result, 16S ribosomal RNA genes of Lactobacillus crispatus, Lactobacillus jensenii and Atopobium vaginae were specifically detected in vaginal fluid and female urine samples. Bacterial genes detected in female urine might have originated from contaminated vaginal fluid. In addition, those of Lactobacillus iners, Lactobacillus gasseri and Gardnerella vaginalis were also detected in non-vaginal body fluids such as semen. Because bacterial genes were successfully amplified in DNA samples extracted by using the general procedure for animal tissues without any optional treatments, DNA samples prepared for the identification of vaginal fluid can also be used for personal identification. In conclusion, 16S ribosomal RNA genes of L. crispatus, L. jensenii and A. vaginae could be effective markers for forensic identification of vaginal fluid.     

Diagnosis of aortic dextroposition on human skeletal remains

The fine macroscopic observation of a young adult female skeleton recovered from a Roman graveyard in Romania revealed distinctive flattening of the vertebra related to a right-sided aorta. Associated bone anomalies may be related to a Kartagener syndrome. This case highlights the fact that visceral anomalies may be diagnosed even on skeletal remains. Such lesions could be useful for osteo-archaeologists, of course, but also for forensic anthropologist investigators dealing with skeletonized remains (for example during the identification process of a dead body, through comparison with known medical data for missing people). More, hypotheses about cause and/or manner of death may be given, and a possibility of genetic confirmation exists.