The effect of bleaching agents on the DNA analysis of bloodstains on different floor coverings.

Blood at crime scenes is one of the most significant traces of evidence in investigation proceedings. Cleaning up these traces with household cleaning products, often containing bleaching agents, inhibits or complicates the detection of DNA. In this study, human blood was applied onto different floor coverings (carpet, laminate, parquet, PVC, tile) and subsequently cleaned with water and bleaching agents (hydrogen peroxide, sodium hypochlorite, DanKlorix®, Vanish Oxi Action®) at different times. Samples have been collected afterwards from the floors. The samples underwent a quantitative and qualitative DNA analysis. Cleaning smooth surfaces with water is usually sufficed to prohibit retrieving a DNA profile in most of the cases. Cleaning carpets was more difficult due to their absorbent surface whereas the use of bleaching agents caused an additional reduction of verifiable DNA concentrations. Retrieving partial or complete profiles after the use of bleaching agents was only possible when cleaning with low concentrations of 3% hydrogen peroxide.

Detection of blood and DNA traces after thermal exposure.

The analysis of blood traces is often of significant reconstructive and evidence-gathering importance. Perpetrators deliberately set fires to destroy evidence. There is little literature regarding the effect of fire and extreme heat on blood and the detection of blood. Blood and DNA are believed to be no longer traceable after exposure to a temperature of 1000 °C. This study exposed different objects of a standardized procedure to temperatures of 300, 700, and 1000 °C. It documented the influence of heat on blood traces through the use of luminol. DNA analysis confirmed that fewer DNA profiles can be created with increasing temperature. However, even after exposure up to a max. of 1000 °C, it was still possible to produce a complete DNA pattern from approx. 60% of the samples. Consequently, crime scenes that have been destroyed by fire should be evaluated with the same attention to detail as the unburned areas.

Blood Trace Evidence on Washed Textiles - a systematic approach.

Luminol has been used for a long time for detecting latent blood traces during police investigations because it is easy to use and does not pose any health risks, while providing trace evidence for DNA analysis. It is often the method of choice for examining clothing. Clothes worn during the offense are often destroyed or washed afterwards by the offenders. The purpose of this study is to show the possibilities of blood and DNA detection on washed clothes by documenting the macroscopic results and their chemiluminescence after washing. The tests comprised different fabrics and laundry detergents including different washing and drying methods. Chemiluminescence was detected on almost all blood-marked samples (95.9%), even after all traces visible to the naked eye have been removed by washing. Evidence of a complete DNA profile or individual alleles could be confirmed in almost all of the test cases (93.3%).

Uptake of gamma-valerolactone--detection of gamma-hydroxyvaleric acid in human urine samples.

Gamma-valerolactone (GVL) is reported to be a substance that can be used as a legal substitute for gamma-hydroxybutyric acid (GHB), which is currently a controlled substance in several countries. Unlike gamma-butyrolactone and 1,4-butanediol, GVL is not metabolized to GHB, which causes the effects after uptake of these two chemicals. In the case of GVL, the lactone ring is split to gamma-hydroxyvaleric acid (GHV or 4-methyl-GHB) by a lactonase. Because of its affinity for the GHB receptor, GHV reveals similar effects to GHB, although it is less potent. Intoxications with GVL, or its use as a date rape drug, are conceivable. Despite these facts, there are no publications in the literature regarding detections of GHV in human samples. This study reports three cases, including five urine samples, in which GHV could be detected in concentrations between 3 and 5.8 mg/L. In one of these cases, a drug-facilitated sexual assault (DFSA) was assumed; four of these samples were from two people suspected of abusing GHB. The results indicate that GVL is used as an alternative to GHB and its precursors and should be taken seriously. GVL or GHV should be included in toxicological analysis, particularly in DFSA cases. More information is needed regarding the pharmacokinetics of GVL/GHV for the meaningful interpretation of positive or negative results.

The new influenza A (H1N1/09): symptoms, diagnostics, and autopsy results.

The first infections of the new H1N1 ("swine flu") virus were announced in April 2009. Soon after, case numbers were observed to be climbing virtually worldwide. In most cases, infections appeared rather mild with typical flu symptoms. In contrast to the seasonal flu, however, cases with vomiting and diarrhea were also reported, and the affected age group seemed to be younger. Sudden and fatal progression affected mostly those under 60 years of age. The autopsy reports of two fatalities with the new influenza are discussed. Multiple postmortem swabs from the nose and throat area determined the H1N1-RNA.

3D reconstruction of emergency cranial computed tomography scans as a tool in clinical forensic radiology after survived blunt head trauma--report of two cases.

When requested to evaluate surviving victims of blunt head trauma the forensic expert has to draw mainly on medical documentation from the time of hospital admission. In many cases these consist of written clinical records, radiographs and in some cases photographic documentation of the injuries. We report two cases of survived severe blunt head trauma where CT images, which had primarily been obtained for clinical diagnostic purposes, were used for forensic assessment. 3D reconstructions of the clinical CT-images yielded valuable information regarding the sequence, number and direction of the impacts to the head, their gross morphology and the inflicting weapon. We conclude that computed tomography and related imaging methods, along with their 3D reconstruction capabilities, provide a useful tool to approach questions in clinical forensic casework.

In vivo wireless ethanol vapor detection in the Wistar rat.

Traditional alcohol studies measure blood alcohol concentration to elucidate the biomedical factors that contribute to alcohol abuse and alcoholism. These measurements require large and expensive equipment, are labor intensive, and are disruptive to the subject. To alleviate these problems, we have developed an implantable, wireless biosensor that is capable of measuring alcohol levels for up to six weeks. Ethanol levels were measured in vivo in the interstitial fluid of a Wistar rat after administering 1 g/kg and 2 g/kg ethanol by intraperitoneal (IP) injection. The data were transmitted wirelessly using a biosensor selective for alcohol detection. A low-power piezoresistive microcantilever sensor array was used with a polymer coating suitable for measuring ethanol concentrations at 100% humidity over several hours. A hydrophobic, vapor permeable nanopore membrane was used to screen liquid and ions while allowing vapor to pass to the sensor from the subcutaneous interstitial fluid.

Cadaver dogs--a study on detection of contaminated carpet squares.

INTRODUCTION: Cadaver dogs are known as valuable forensic tools in crime scene investigations. Scientific research attempting to verify their value is largely lacking, specifically for scents associated with the early postmortem interval. The aim of our investigation was the comparative evaluation of the reliability, accuracy, and specificity of three cadaver dogs belonging to the Hamburg State Police in the detection of scents during the early postmortem interval. MATERIAL AND METHODS: Carpet squares were used as an odor transporting media after they had been contaminated with the scent of two recently deceased bodies (PMI<3h). The contamination occurred for 2 min as well as 10 min without any direct contact between the carpet and the corpse. Comparative searches by the dogs were performed over a time period of 65 days (10 min contamination) and 35 days (2 min contamination). RESULTS: The results of this study indicate that the well-trained cadaver dog is an outstanding tool for crime scene investigation displaying excellent sensitivity (75-100), specificity (91-100), and having a positive predictive value (90-100), negative predictive value (90-100) as well as accuracy (92-100).

Desorption characteristics of uncoated silicon microcantilever surfaces for explosive and common nonexplosive vapors.

We measured the desorption of explosive trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), and hexahydro-1,3,5-triazine (RDX) vapors from piezoresistive silicon microcantilevers under ambient air. Depending on the amount of vapor loaded on the cantilever, TNT desorption took a few minutes to tens of minutes (for nanogram quantities). On the other hand, no significant loss of PETN or RDX was observed after many hours. We also measured desorption of common "nonexplosive" compounds (water, acetone, and ethyl alcohol) and observed that desorption was too fast to be measured. There is a good correlation between the desorption time and the melting point (or the vapor pressure) of a particular substance. In principle, this method can be used to measure desorption rates of various substances from cantilever surfaces.

Application of compact ultrasound imaging device to postmortem diagnosis.

In regions with low autopsy rates, forensic examiners often have to rely on external findings. Imaging techniques can assist the external examination and provide a more objective diagnosis. The SonoSite 180, a portable ultrasound device, was used for the examination of dead bodies. The influence of different degrees of decomposition was estimated. Even in cases with intestinal gas formation images of internal organs could be obtained with special techniques. Various pathological findings were detected by ultrasound and verified by autopsy (e.g. pericardial tamponade, cardiac hypertrophy, fatty liver, aortic aneurysm, metastatic liver, etc.). The experiences with the SonoSite 180 are promising. The device can be carried to the death scene or to the morgue and therefore serve as a valuable tool for medicolegal applications.

[Suicidal electrocution using timers. Case reports and review of the literature]. / Suizidale Strombeibringung unter Verwendung von Zeitschaltuhren. Kasuistiken und Literaturübersicht.

Suicidal electrocution using a time switch is relatively rare. Based on two cases from the authors' own forensic material and seven cases from literature peculiarities regarding the concomitant intake of medicines (benzodiazepines) and alcohol are discussed and comments are made how to proceed in the criminal and forensic investigation of such cases.

[Unintentional gunshot during police intervention]. / Der ungewollte Schuss im Polizeieinsatz.

33 cases of unintentional handgun use by police officers during operation since 1983 in Northern Germany have been evaluated. These cases have been selected from our own investigations and from prosecutors' and police departments' files and records. It was intended to find out criteria for forensic expertise. The unintended use of a handgun was always influenced in a decisive and causal manner by the behaviour of the delinquents (resistance, assault, escape). The confrontation of the police officer with the violence of aggressive offenders was of immediate importance for triggering the shot in various kinds of police operation. Sensorically caused, reflex muscle contractions as a consequence of a great effort, a loss of balance or fright when simultaneously protecting oneself with weapon in hand can be made responsible for the unvoluntary shot. In 10 cases (30%) persons were injured, 2 times lethally. As a whole, the consequences were of random nature, they could be explained by the series of actions in each case. The type and technical state of the weapons in use have not influenced the unintentional use. A behaviour of the police officers offending against the legally required care was stated in two of the investigated cases. Considering our investigations and the many policemen killed in duty we state that securing oneself in time with a weapon at the ready in critical phases of operations cannot be successfully replaced by any other method of self defense.

Skin and soft tissue artifacts due to postmortem damage caused by rodents.

Five cases of postmortem bite-injuries inflicted by rodents are presented (five males between 41 and 89 years; three cases caused by mice, one case by rats, one case of possible mixed rodent activity by rats and mice). The study presents a spectrum of phenomenological aspects of postmortem artifacts due to rodent activity to fresh skin and soft tissue: the majority of the injuries have a circular appearance. The wound margins are finely serrated with irregular edges and circumscribed 1-2 mm intervals within, partly showing protruding indentations up to 5 mm. Distinct parallel cutaneous lacerations deriving from the biting action of the upper and lower pairs of the rodents incisors are diagnostic for tooth marks of rodent origin but cannot always be found. No claw-induced damage can be found in the skin beyond the wound margins. Areas involved in the present study were: exposed and unprotected parts of the body, such as eyelids, nose and mouth (representing moist parts of the face); and the back of the hands. Postmortem rodent activity may occasionally be expected on clothed and therefore protected parts of the body. The phenomenon of postmortem rodent activity to human bodies can be found indoors especially under circumstances of low socioeconomic settings; outdoors this finding is particularly observed among fatalities among homeless people.

Pharmacokinetics and antibacterial efficacy in vivo of beta-lactam combinations against Proteus vulgaris.

The pharmacokinetics and antibacterial efficacy of mezlocillin, cefotaxime, cefoperazone and the mezlocillin/cefalosporin combinations, respectively, were studied by adopting the granuloma pouch model in rats. Exudate concentrations of mezlocillin were higher after combined i.v. injection with a cefalosporin as determined microbiologically and by high performance liquid chromatography (HPLC). Cefoperazone levels, however, were not affected. Not metabolized cefotaxime concentrations as determined by HPLC were also not increased following simultaneous injection with mezlocillin. Cefotaxime metabolite concentrations, however, were generally higher than unchanged cefotaxime and increased upon repeated administration of cefotaxime alone and to a greater extent when combined with mezlocillin. Antibacterial efficacy of mono- or combined chemotherapy was correlated to beta-lactamase inducibility of the test strains insofar as drugs acting as good or moderate enzyme inducers were ineffective in vivo. The combined therapy of mezlocillin with cefotaxime was effective in this case. This result was also correlated to the bioavailability of the beta-lactams in infected pouches. Due to the degree of beta-lactamase inducibility and production, drug levels were either decreased or not detectable.

Kinetic in vitro studies of antibacterial effects of the combination of new penicillins and cefalosporins against Proteus vulgaris.

In vitro studies simulating human as well as animal pharmacokinetics were performed in order to assess the combination effect of mezlocillin plus cefotaxime or cefoperazone. Different Proteus vulgaris strains exhibiting varying degrees of in vivo response to the antibiotics were selected for this study. Retardation of bactericidal efficacy was caused by the combination of mezlocillin plus cefoperazone in those strains exhibiting high degrees of beta-lactamase inducibility and being exposed to high levels of cefoperazone; lower drug levels caused indifferent effects. In any case, cultures were completely sterilized during the study period. Among the three beta-lactams studied, cefoperazone was the best beta-lactase inducer, while cefotaxime and mezlocillin exhibited only minor inducer activity. The combination of mezlocillin with cefotaxime, being only minimally active as beta-lactamase inducers, caused either indifferent or synergistic effects when simulating drug disposition in humans or animals. beta-Lactamase-negative strains exhibited only indifferent effects. The augmented bioavailability of mezlocillin due to its simultaneous administration with a cefalosporin resulted in an increased antibacterial efficacy.

[Substitution of venous valves in animal experiments]. / Der Ersass von Venenklappen im Tierversuch.

60 to 70 per cent of properly transplanted autologous venous grafts with intact valves maintain the functional capability of their valves. The procedure might be of clinical importance in the treatment of the postthrombotic syndrome.