A rare case of serial killing by poisoning

Chemical investigation of biological trace evidence; toxicological screening of waste residues obtained from DNA extraction processes

In a forensic scenario, if biological stains are found in very small quantities, these are usually collected for DNA analyses, considered essential for the forensic investigation and thus excluding possible investigations by other forensic disciplines as forensic toxicology. We developed an experimental study to evaluate the feasibility of analyzing DNA extraction residues obtained from DNA extraction procedures to perform toxicological analysis, with the aim to extract both genetic and toxicological information without affecting or compromising the genetic sample and/or DNA extraction. DNA extraction from four blood samples (fortified with 5 molecules of interest with a final concentrations of 1 µg/mL, 100 ng/mL, 10 ng/mL and 5 ng/mL, respectively) were analyzed with QIAGEN QIAmp® DNA Mini kit. Three waste residues collected from the DNA extraction were analyzed for the toxicological investigation via Solid-Phase Extraction and High-Performance Liquid Chromatography-Tandem Mass Spectrometry analyses (Thermo Scientific™ TSQ Fortis™ II Triple-Quadrupole Mass Spectrometer). The analytical investigation revealed that our analytes of interest were detected in two different residues of the DNA extraction procedure, allowing both genetic and toxicological analyses without affecting the DNA identification. At last, the experimental protocol was applied to a hypothetical case, with encouraging results and allowing the identification of our molecules of interest.

Histological paraffin-embedded block: a good alternative specimen to detect the use of opiates at least 20 years ago

PURPOSE

Since the solely certain remnants of a performed autopsy are formalin-fixed paraffin-embedded (FFPE) samples, stored in the archives of every institute of legal medicine, we managed to extract molecules of toxicological interest from these specimens.

METHODS

We assessed the analysis of ten fresh liver samples collected from heroin-related deaths and then histologically processed the same samples. The embedded blocks were then extracted by means of a new extracting method and the eluates were measured. We also selected five toxicological cases of heroin-related fatalities that were examined 20 years ago, collected the toxicological result documents of the analysis that were carried out at the time and then processed the corresponding FFPE liver samples that were stored in the archives.

RESULTS

We managed to isolate heroine-related metabolites from 20-year-old paraffin-embedded blocks and calculated ratios to evaluate the performance of our new extraction.

CONCLUSIONS

According to our study, it is feasible to carry out a toxicological examination on old histological samples and, therefore, this matrix can be considered as a new alternative specimen for chemical-analytical evaluations of past cases or when fresh samples are not available anymore. The new extractive method was evaluated as efficient in treating these complex, paraffin-embedded samples. It was surprising that the target compounds could be quantitated from FFPE bocks created as long as 20 years ago.

Determination of drugs in exhumed liver and brain tissue after over 9 years of burial by liquid chromatography-tandem mass spectrometry-Part 2: Benzodiazepines, opioids, and further drugs

In this publication, benzodiazepines, opioids, and further drugs were analyzed in exhumed brain and liver tissue samples in 116 cases (total) after 9.5-16.5 years of burial. Solid phase extraction followed by liquid chromatography-tandem mass spectrometry was applied. Data from literature is listed summarizing the detectability of the presented analytes after a certain time of burial. In our study, 60% of the analyzed benzodiazepines, 100% of the opioids, and 82% of further drugs were detectable. Only the benzodiazepines lorazepam, nitrazepam, flunitrazepam, and its metabolite norflunitrazepam, and the drugs butylscopolamine, metronidazole, and omeprazole were not detectable at all. Percentage of positive findings (total, and separately for brain and liver tissue) and postmortem period are listed for each analyte. Correlation of detectability depending on postmortem period and condition of tissue are presented exemplarily for midazolam. No substantial correlation was observed. Despite a long time of burial, most benzodiazepines, opioids, and further drugs were detectable in the examined tissue samples. Our results may be a good support for future exhumations in which toxicological analyses are relevant.

Digoxin: Pharmacology and toxicology-A review

Digoxin is a cardiac glycoside used as drug in case of heart problems, including congestive heart failure, atrial fibrillation or flutter, and certain cardiac arrhythmias. It has a very narrow therapeutic window of the medication. Digoxin is toxic substance with well known cardiotoxic effect. In this work, pharmacology and toxicology of digoxin are summarized; Its pharmacokinetics, pharmacodynamics, available acute toxicity data (different species, different administration routes) are summarized in this article. Moreover, its treatment side effect and human poisonings are thoroughly discussed. Finally, appropriate therapy regimen is proposed.