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.

Neuropathological alterations in drug abusers : The involvement of neurons, glial, and vascular systems

Because the effects of drug abuse on the cellular elements of the human brain have not been studied systematically, an investigation was performed using histology, immunohistochemistry, and morphometry. The main cortical and subcortical brain areas of 50 polydrug deaths were analyzed as compared with controls.In the brains of drug abusers, a significant neuronal loss was present. Interestingly, the number of glial fibrillary acidic protein (GFAP)-positive astrocytes was reduced. the numerical density of perivascular and parenchymal microglia was increased in the white matter and in most subcortical regions. In the white matter there were widespread β-amyloid precursor protein deposits. Furthermore, there was a prominent vascular hyalinosis, endothelial cell proliferation, and a loss of immunoreactivity for collagen type IV within the vascular basal lamina.The neuronal loss seems to be the result of a direct impairment of nerve cells and, indirectly, to a damage of astrocytes, axons, and the microvasculature. The reduction of GFAP-positive astrocytes is also indicative of a drug-induced damage. The axonal injury suggests a toxic-metabolic drug effect, whereas the concomitant activation of microglia is indicative of a long-standing progressive process. The noninflammatory vasculopathy can be considered as the morphological substrate of a disturbed blood-brain barrier. Our findings demonstrate that drugs of abuse initiate a cascade of interacting toxic, vascular, and hypoxic factors that finally result in widespread disturbances within the complex network of central nervous system cell-cell interactions.

Neuropathology of Chronic Alcohol Abuse

Alcohol abuse and dependence are serious public health problems worldwide, resulting in significant morbidity, mortality, and legal implications. Therefore, sudden unexpected, suspicious, or violent death in alcohol consuming persons are frequently seen in the forensic setting. Alcohol-induced brain damage is predominantly caused by nutritional deficiencies and repeated withdrawal syndrome. Brain lesions associated with heavy alcohol consumption include brain atrophy, hepatic encephalopathy, and central pontine myelinolysis. In addition, the dementing conditions Wernicke-Korsakoff syndrome, acquired hepatocerebral degeneration, Marchiafava-Bignami disease, and pellagrous encephalopathy are closely associated with chronic alcohol consumption. In neuroradiological and autopsy studies, cerebral and cerebellar atrophy has been demonstrated in alcoholics. There is a regional selectivity, with the frontal lobes being particularly affected. Moreover, a disproportionate loss of cerebral white matter relative to cerebral cortex suggests that a major neurotoxic effect of chronic alcohol consumption predominantly affects the white matter.

Usefulness of SNPs as Supplementary Markers in a Paternity Case with 3 Genetic Incompatibilities at Autosomal and Y Chromosomal Loci

BACKGROUND

In kinship testing, investigation of 15 short tandem repeats (STRs) usually provides decisive genetic information for resolving relationship cases. However, in complex deficiency cases, in cases with more than 2 mutations at different STR loci or when close (untested) relatives of the alleged father are suggested to be the biological father of the child, STR typing alone may not be sufficient. In these cases, the application of supplementary markers such as single nucleotide polymorphisms (SNPs) is recommended.

METHODS

We describe a paternity case with 3 genetic incompatibilities (Penta D, VWA, and DYS385) between the alleged father and the child after analyzing 23 autosomal and 16 Y chromosomal STR loci. The question arose as to whether the alleged father could be excluded and a related person could be the biological father of the child, or whether the observed genetic incompatibilities were mutations. Interestingly, the 2 excluded full brothers of the alleged father possessed identical genetic incompatibilities at locus VWA and DYS385 as the alleged father.

RESULTS AND CONCLUSIONS

Additional performance of a 50-plex SNP assay demonstrated that the observed mismatches were indeed mutations and the alleged father was the biological father of the child. The results show the usefulness of SNPs as supplementary markers in relationship testing when STR analyses show ambiguous results.

Elevated oleic acid serum concentrations in patients suffering from alcohol dependence

Background

Alcohol-induced damages such as brain atrophy and fatty liver are closely related to a disturbed lipid metabolism. In animal models, a linkage between chronic alcohol consumption and changes in fatty acid (FA) composition in various organs and cells is well known and there is some indication that this phenomenon could be linked to behavioural alterations associated with alcohol addiction such as craving. However, the influence of ethanol on secretory FA has not been investigated so far. In this study, we therefore aimed at investigating whether there is a significant change of serum FA composition in patients suffering from alcohol dependence. We compared patients before and after treatment (detoxication) with control individuals who did not suffer from addiction. The roles of age, the duration and intensity of alcohol use and lifestyles were considered.

Methods

Serum FA was measured in 73 male ethanol dependent patients before and after alcohol withdrawal in an in-patient setting. Additionally, of this group, 45 patients were matched with 45 healthy male volunteers as controls.

Results

We found significant differences in the FA composition before and after detoxication as well as between patients and controls. After detoxication, the values changed towards the ones in healthy controls. The main finding during acute alcohol use was an increased oleic acid concentration above the level of the linoleic acid concentration.

Conclusions

An elevated oleic/linoleic acid ratio seems to be a state marker for acute alcohol use and may be a relevant trait marker during detoxification and possibly the subsequent therapeutic measures. The results of this pilot study need to be replicated in a larger study also including female patients. Further, the specificity of this potential biomarker needs to be determined.

Neuropathological alterations in cocaine abuse

Cocaine abuse represents a significant health issue worldwide. Besides cardiovascular complications, psychiatric and neurologic symptoms are the most common manifestations of cocaine toxicity. In cocaine abusers brain abnormalities have been shown with computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), or single photon emission computed tomography (SPECT). The spectrum of neuropathologic alterations seen in cocaine abusers is broad. The major findings consist of vascular complications such as stroke, subarachnoid and intracerebral hemorrhages and cerebral ischemia. Persons with underlying arteriovenous malformation or aneurysm are especially prone for such events. Except for a few incidents of vasculitis, the etiology of cocaine- related cerebrovascular events is still unclear. Cocaine-induced vasospasm, impaired hemostasis and platelet function, as well as decreased cerebral blood flow, have been proposed as possible mechanisms. On the molecular level, alterations in the expression of transcription factors and changes of brain neurotransmitter systems have been reported.

The neurobiology of suicide - A Review of post-mortem studies

The neurobiology of suicidal behaviour, which constitutes one of the most serious problems both in psychiatry and general medical practice, still remains to a large degree unclear. As a result, scientists constantly look for new opportunities of explaining the causes underlying suicidality. In order to elucidate the biological changes occurring in the brains of the suicide victims, studies based on post-mortem brain tissue samples are increasingly being used. These studies employ different research methods to provide an insight into abnormalities in brain functioning on various levels, including gene and protein expression, neuroplasticity and neurotransmission, as well as many other areas. The aim of this paper to summarize the available data on the post-mortem studies, to provide an overview of main research directions and the most up-to-date findings, and to indicate the possibilities of further research in this field.

Quantitative analysis of astrogliosis in drug-dependent humans

Drug addiction is a chronic, relapsing disease caused by neurochemical and molecular changes in the brain. In this human autopsy study qualitative and quantitative changes of glial fibrillary acidic protein (GFAP)-positive astrocytes in the hippocampus of 26 lethally intoxicated drug addicts and 35 matched controls are described. The morphological characterization of these cells reflected alterations representative for astrogliosis. But, neither quantification of GFAP-positive cells nor the Western blot analysis indicated statistical significant differences between drug fatalities versus controls. However, by semi-quantitative scoring a significant shift towards higher numbers of activated astrocytes in the drug group was detected. To assess morphological changes quantitatively, graph-based representations of astrocyte morphology were obtained from single cell images captured by confocal laser scanning microscopy. Their underlying structures were used to quantify changes in astroglial fibers in an automated fashion. This morphometric analysis yielded significant differences between the investigated groups for four different measures of fiber characteristics (Euclidean distance, graph distance, number of graph elements, fiber skeleton distance), indicating that, e.g., astrocytes in drug addicts on average exhibit significant elongation of fiber structures as well as two-fold increase in GFAP-positive fibers as compared with those in controls. In conclusion, the present data show characteristic differences in morphology of hippocampal astrocytes in drug addicts versus controls and further supports the involvement of astrocytes in human pathophysiology of drug addiction. The automated quantification of astrocyte morphologies provides a novel, testable way to assess the fiber structures in a quantitative manner as opposed to standard, qualitative descriptions.

Contemporary paternal genetic landscape of Polish and German populations: from early medieval Slavic expansion to post-World War II resettlements

Homogeneous Proto-Slavic genetic substrate and/or extensive mixing after World War II were suggested to explain homogeneity of contemporary Polish paternal lineages. Alternatively, Polish local populations might have displayed pre-war genetic heterogeneity owing to genetic drift and/or gene flow with neighbouring populations. Although sharp genetic discontinuity along the political border between Poland and Germany indisputably results from war-mediated resettlements and homogenisation, it remained unknown whether Y-chromosomal diversity in ethnically/linguistically defined populations was clinal or discontinuous before the war. In order to answer these questions and elucidate early Slavic migrations, 1156 individuals from several Slavic and German populations were analysed, including Polish pre-war regional populations and an autochthonous Slavic population from Germany. Y chromosomes were assigned to 39 haplogroups and genotyped for 19 STRs. Genetic distances revealed similar degree of differentiation of Slavic-speaking pre-war populations from German populations irrespective of duration and intensity of contacts with German speakers. Admixture estimates showed minor Slavic paternal ancestry (~20%) in modern eastern Germans and hardly detectable German paternal ancestry in Slavs neighbouring German populations for centuries. BATWING analysis of isolated Slavic populations revealed that their divergence was preceded by rapid demographic growth, undermining theory that Slavic expansion was primarily linguistic rather than population spread. Polish pre-war regional populations showed within-group heterogeneity and lower STR variation within R-M17 subclades compared with modern populations, which might have been homogenised by war resettlements. Our results suggest that genetic studies on early human history in the Vistula and Oder basins should rely on reconstructed pre-war rather than modern populations.

Neuropathological Alterations in Illicit Drug Abuse

A variety of neuropathological findings has been described in illicit drug abusers. The majority of these alterations result from the consequences of hypoxia-ischemia and from cerebrovascular diseases. Within the last few years, widespread morphological alterations of the cellular elements of the brain have been detected. These changes consist of neuronal loss, a numerical reduction of astrocytes, widespread axonal damage with concomitant microglial activation and reactive and degenerative changes of the cerebral microvessels. Based on various studies there is also concern that drug abusers develop neurodegeneration or Parkinsonism as they age. However, whether or to what extent neurodegeneration occurs in human drug abusers remains to be established. In the present paper a brief overview on the neuropathological changes in drug abuse is presented for the forensic pathologist/toxi-cologist with reference to the most pertinent literature.

DNA methylation analysis of the angiotensin converting enzyme (ACE) gene in major depression

BACKGROUND

The angiotensin converting enzyme (ACE) has been repeatedly discussed as susceptibility factor for major depression (MD) and the bi-directional relation between MD and cardiovascular disorders (CVD). In this context, functional polymorphisms of the ACE gene have been linked to depression, to antidepressant treatment response, to ACE serum concentrations, as well as to hypertension, myocardial infarction and CVD risk markers. The mostly investigated ACE Ins/Del polymorphism accounts for ~40%-50% of the ACE serum concentration variance, the remaining half is probably determined by other genetic, environmental or epigenetic factors, but these are poorly understood.

MATERIALS AND METHODS

The main aim of the present study was the analysis of the DNA methylation pattern in the regulatory region of the ACE gene in peripheral leukocytes of 81 MD patients and 81 healthy controls.

RESULTS

We detected intensive DNA methylation within a recently described, functional important region of the ACE gene promoter including hypermethylation in depressed patients (p = 0.008) and a significant inverse correlation between the ACE serum concentration and ACE promoter methylation frequency in the total sample (p = 0.02). Furthermore, a significant inverse correlation between the concentrations of the inflammatory CVD risk markers ICAM-1, E-selectin and P-selectin and the degree of ACE promoter methylation in MD patients could be demonstrated (p = 0.01 - 0.04).

CONCLUSION

The results of the present study suggest that aberrations in ACE promoter DNA methylation may be an underlying cause of MD and probably a common pathogenic factor for the bi-directional relationship between MD and cardiovascular disorders.

Experimental evaluation of the risk of extradiscal thermal damage in intradiscal electrothermal therapy (IDET)

BACKGROUND

In 2000 the intradiscal electrothermal therapy (IDET) procedure for the treatment of discogenic pain was introduced. The technique involves the positioning of an intradiscal catheter with a temperature-controlled thermal resistive heating coil at the inner posterior annulus. The therapeutic mechanism of IDET combines the thermo-coagulation of native nociceptors and in-grown nonmyelinated nerve fibers with collagen shrinkage, stabilizing annular fissures. Thermal nerve root injuries were described with IDET. The temperature in relation to the distance from the catheter tip was investigated. The intradiscal temperature distribution during treatment with IDET was also described.

OBJECTIVE

To examine the temperature distribution outside the disc near neural structures and the risk of thermal damage to nerve tissue during a correctly performed IDET procedure.

STUDY DESIGN

Experimental study.

SETTING

Biomechanical laboratory of an academic orthopedic surgery department.

METHODS

Testing was performed on cadaveric human lumbar spines with 10 intact intervertebral discs in a circulating water bath. Five thermocouples were attached to different locations on the disc. The temperature was recorded for 26 minutes. In addition, surface temperatures were recorded using an infrared camera. For the application of IDET, we used the Electrothermal 20S Spine System by Smith & Nephew and the standard clinical protocol.

RESULTS

The shape of the recorded temperature curves was quite heterogeneous. Inside the spinal canal, temperatures as high as 45.2°C were recorded for a very short time. Temperature monitoring with the infrared camera demonstrated a change in temperature clearly restricted to the nucleus of the disc.

LIMITATIONS

The temperature distribution depends on the exact position of the IDET probe, which will never be 100% identical between individual experiments.

CONCLUSION

This study shows that temperatures generated within the spinal canal during IDET do not appear to be high enough to cause nerve damage.

Heat distribution of polymerisation temperature of bone cement on the spinal canal during vertebroplasty

PURPOSE

In the last 15 years, vertebroplasty and kyphoplasty have become established operative procedures for treating osteoporotic vertebral-body fractures and vertebral bodies afflicted with metastases. These procedures are quickly performed with few personnel and material resources and have a low rate of complications. However, cases of neurological impairment are reported in the scientific literature. We analysed whether potentially harmful heat is radiated/conducted by the polymerisation temperature of polymethylmethacrylate (PMMA) bone cement in the spinal canal.

METHODS

We performed vertebroplasty on 25 vertebral bodies and measured the temperature distribution during polymerisation of bone cement within the spinal canal using heat probes placed in the respective areas. The vertebral bodies were located in a circulating water bath at 37°C.

RESULTS

During polymerisation of the bone cement, a temperature rise was measured. The peak temperature was reached after few minutes. Temperature curves differed; a maximum temperature of up to 43.16°C was detected for a few seconds only.

CONCLUSION

When vertebroplasty is performed correctly, there is no temperature development that could eventually damage the spinal cord or spinal nerves.