A study concerning the blood/breath alcohol conversion factor Q: concentration dependency and its applicability in daily routine.

The conversion factor Q, obtained by division of blood alcohol concentration (BAC) by breath alcohol concentration (BrAC) is a widely discussed topic due to its great variance. By Austrian law, regulations frequently require an estimation of a corresponding BAC by a measured BrAC. It is known that Q depends among other things, on the alcohol kinetic state of the person being tested, which mathematically can be transformed to a dependency on the BrAC. Theoretically calculated Q values per BrAC level form a hyperbola shaped curve, thus decreasing with increasing BrAC values. Applying Austrian forensic standards for BAC and BrAC measurements, these calculations were verified in a study under practical conditions with BAC and BrAC data of 390 individuals. Q decreases from 2629 (+/- 455) for BrAC levels < 0.1 mg/l to 2229 (+/- 160) for a BrAC range of 0.4-0.5 mg/l and increases again to 2428 (+/- 124) for BrAC levels > 0.6 mg/l. Since these results were obtained under realistic practical conditions they can be directly applied in routine forensic expert opinion and can eliminate avoidable variances in the calculation of Q.

Analysis of artificially degraded DNA using STRs and SNPs--results of a collaborative European (EDNAP) exercise.

Recently, there has been much debate about what kinds of genetic markers should be implemented as new core loci that constitute national DNA databases. The choices lie between conventional STRs, ranging in size from 100 to 450 bp; mini-STRs, with amplicon sizes less than 200 bp; and single nucleotide polymorphisms (SNPs). There is general agreement by the European DNA Profiling Group (EDNAP) and the European Network of Forensic Science Institutes (ENFSI) that the reason to implement new markers is to increase the chance of amplifying highly degraded DNA rather than to increase the discriminating power of the current techniques. A collaborative study between nine European and US laboratories was organised under the auspices of EDNAP. Each laboratory was supplied with a SNP multiplex kit (Foren-SNPs) provided by the Forensic Science Service, two mini-STR kits provided by the National Institute of Standards and Technology (NIST) and a set of degraded DNA stains (blood and saliva). Laboratories tested all three multiplex kits, along with their own existing DNA profiling technique, on the same sets of degraded samples. Results were collated and analysed and, in general, mini-STR systems were shown to be the most effective. Accordingly, the EDNAP and ENFSI working groups have recommended that existing STR loci are reengineered to provide smaller amplicons, and the adoption of three new European core loci has been agreed.

Post-mortem interval estimation of human skeletal remains by micro-computed tomography, mid-infrared microscopic imaging and energy dispersive X-ray mapping.

In this study different state-of-the-art visualization methods such as micro-computed tomography (micro-CT), mid-infrared (MIR) microscopic imaging and energy dispersive X-ray (EDS) mapping were evaluated to study human skeletal remains for the determination of the post-mortem interval (PMI). PMI specific features were identified and visualized by overlaying molecular imaging data and morphological tissue structures generated by radiological techniques and microscopic images gained from confocal microscopy (Infinite Focus (IFM)). In this way, a more distinct picture concerning processes during the PMI as well as a more realistic approximation of the PMI were achieved. It could be demonstrated that the gained result in combination with multivariate data analysis can be used to predict the Ca/C ratio and bone volume (BV) over total volume (TV) for PMI estimation. Statistical limitation of this study is the small sample size, and future work will be based on more specimens to develop a screening tool for PMI based on the outcome of this multidimensional approach.

Evaluating sequence-derived mtDNA length heteroplasmy by amplicon size analysis.

Length heteroplasmy (LH) in mitochondrial (mt)DNA is usually observed in homopolymeric tracts and manifest as mixture of various length variants. The generally used difference-coded annotation to report mtDNA haplotypes does not express the degree of LH variation present in a sample, even more so, it is sometimes difficult to establish which length variants are present and clearly distinguishable from background noise. It has therefore become routine practice for some researchers to call the dominant type, the "major molecule", which represents the LH variant that is most abundant in a DNA extract. In the majority of cases a clear single dominant variant can be identified. However, in some samples this interpretation is difficult, i.e. when (almost) equally quantitative LH variants are present or when multiple sequencing primers result in the presentation of different dominant types. To better understand those cases we designed amplicon sizing assays for the five most relevant LH regions in the mtDNA control region (around ntps 16,189, 310, 460, 573, and the AC-repeat between 514 and 524) to determine the ratio of the LH variants by fluorescence based amplicon sizing assays. For difficult LH constellations derived by Sanger sequencing (with Big Dye terminators) these assays mostly gave clear and unambiguous results. In the vast majority of cases we found agreement between the results of the sequence and amplicon analyses and propose this alternative method in difficult cases.

Evaluation of an extended set of 15 candidate STR loci for paternity and kinship analysis in an Austrian population sample.

We investigated 15 polymorphic short tandem repeat (STR) loci (D1S1656, D7S1517, D8S306, D8S639, D9S304, D10S2325, D11S488, D12S391, D14S608, D16S3253, D17S976, D18S1270, D19S253, D20S161, and D21S1437) which are not included in the standard sets of forensic loci. The markers were selected according to the complexity of the polymorphic region: Of the 15 investigated loci, 7 loci showed a simple repeat structure (D9S304, D10S2325, D14S608, D16S3253, D18S1270, D19S253, and D21S1437), 3 loci (D7S1517, D12S391, and D20S161) consisted of compound repeat units, and 5 loci (D1S1656, D8S306, D8S639, D11S488, and D17S976) showed a more complex polymorphic region partly including different repeat blocks and incomplete repeat units, which resulted in a relatively high proportion of intermediate alleles. A population study on a sample of 270 unrelated persons from Austria was carried out. We did not observe significant deviations from Hardy-Weinberg expectations. The combined probability of exclusion for the 15 loci was 0.99999998. In combination with the conventional set of STR markers included in commercially available kits (no linkage was observed between these 15 loci and the Powerplex 16 System loci), these markers are approved as highly discriminating forensic tools, also suitable for the analysis of difficult paternity and kinship constellations.

A new "miniSTR-multiplex" displaying reduced amplicon lengths for the analysis of degraded DNA.

A multiplex PCR was designed for the loci D2S1338, D16S539, D18S51, TH01 and FGA using redesigned primers in order to reduce the lengths of the amplification products compared to the designs used in commercially available multiplex PCR kits, also including amelogenin. The new PCR primers were used to amplify highly degraded DNA from casework samples, which had shown no or only poor results for these loci in previous analyses with standard primer sets. The application of the new miniSTR-multiplex resulted in an increased overall typing success rate for degraded DNA samples. In a concordance study between the conventional and the newly designed primers, no genotype differences were revealed in 124 randomly selected individuals.

Cross-reactivity of the CEDIA buprenorphine assay with opiates: an Austrian phenomenon?

When testing the Microgenics CEDIA assay for immunological buprenorphine analysis, cross-reactivity between the buprenorphine reagents and opiates was observed at concentrations higher than 120 mg/l morphine, 320 mg/l methadone, 30 mg/l codeine, 60 mg/l dihydrocodeine and 520 mg/l morphine-3-glucuronide. The cross-reactivity with morphine has the greatest impact on routine screening as opiate maintenance therapy in Austria is also performed with slow-release oral morphine. The use of a second cutoff value of 30 mug/l for urine samples that are (immunologically) positive for opiates is therefore suggested, compared to the cutoff value of 5 microg/l proposed by the manufacturer.

Unusual variant alleles in commonly used short tandem repeat loci.

Unusually large variant alleles were observed in the short tandem repeat (STR) systems D3S1358 and D21S11, both of which are included in the international standard set of loci (ISSOL) and routinely typed in National DNA intelligence databases worldwide. The observed alleles fell within the size range of the adjacent STR marker, which could easily cause problems with respect to correct allele assignments for both loci concerned. We compared the amplification and potential interpretation with three different commercially available kits, which are frequently used in forensic work. PCR products were cloned and sequenced in order to determine the structure of these unusual allele variants and confirm their size and designation (D3S1358 allele 26, D21S11 allele 46). In the locus D21S11 we observed an as yet undescribed partial duplication of the constant region.

New sensitive amplification primers for the STR locus D2S1338 for degraded casework DNA.

PCR primers for the locus D2S1338 were redesigned in order to reduce the length of the amplification product compared with the conventional design. The new amplification primers were applied to highly degraded casework samples, which gave no or only weak results for D2 in previous analyses. The application of the new primers resulted in an increased overall typing success rate. In a concordance study between the conventional and the newly designed primers, no genotype differences were revealed in 503 randomly selected individuals. This suggests robust amplification conditions with respect to mutation-based allele drop-out.

Fatal accident caused by isoflurane abuse.

A fatal accident after isoflurane abuse is presented in this report. A hospital employee was found dead in the operating area with a plastic bag over his head. In his locker an almost empty bottle of isoflurane was found. Autopsy revealed signs of asphyxiation and toxicological examination revealed nordazepam and isoflurane in non-toxic concentrations in the blood. Quantification of the anaesthetic was also carried out in urine, gastric contents, liver, kidney and brain samples, and in addition, oxazepam, prothipendyl and metabolites of midazolam and prothipendyl were found in the urine. Although the drug problems of the deceased were known before, no efforts had been made to restrict access to these drugs.

Complete detachment of an aortic valve prosthesis 10 years after implantation.

A 47-year-old male patient died unexpectedly 10 years after replacement of the aortic valve with a Carbomedics heart valve prosthesis required for post-endocarditic valve stenosis. The man was in regular medical attendance by his general practitioner and in hospital. Clinical data and examinations did not suggest the reoccurrence of endocarditis. Three months before his death a haemolytic anaemia of unknown genesis was diagnosed. One afternoon, while lifting a heavy object, the man suffered acute chest pain and collapsed. Resuscitation failed and the patient died in hospital. Autopsy revealed the completely detached valve prosthesis within the ascending aorta. Histological examination confirmed a chronic endocarditis at the site of the valve implantation.

STR loci Penta D and Penta E: Austrian Caucasian population data.

Allele frequencies for the short tandem repeat (STR) loci Penta D and Penta E, included in the PowerPlex 16 kit were obtained from a sample of 269 unrelated Austrian Caucasian individuals. Both loci met Hardy-Weinberg expectations.

Fatal intoxication with omethoate.

A case of suicide with the insecticide omethoate is reported. An 18-year-old apprentice gardener had ingested an unknown amount of omethoate. His body was found in his room lying in the storage space under his bed. The autopsy first showed multiple superficial incisions in the skin of his wrists, furthermore hemorrhagic pulmonary oedema, dilation of the right cardiac ventricle and oedema of the brain. The gastric mucosa was swollen and showed a dark brownish colour. An intensive, chemical-like smell rose from the corpse and organs. Toxicological analysis detected omethoate in cardiac blood (208 micro g/ml), urine (225 micro g/ml) and bile (524 micro g/ml), in the liver (341 micro g/ml) and kidneys (505 micro g/ml). In the gastric content the level was 48223 micro g/ml. The amount of the active AChE in peripheral blood serum was reduced to less than 0.2% of the normal level. To our knowledge no case of a fatal suicide by ingestion of omethoate has been reported in literature.

Airbag contact in traffic accidents: DNA detection to determine the driver identity.

A total of 34 deployed driver and passenger airbags from altogether 20 vehicles after frontal collisions were investigated. In 80% of the airbags possible biological traces could be located with an alternative light source (ALS, Polilight) at a wavelength of 450-470 nm. These traces were swabbed, a part of them additionally cut and subjected to DNA analysis, which led to comparable SGMplus profiles in about 60%. In the 20% of the airbags on which no possible biological traces could be located, the whole surfaces were swabbed. In these cases subsequent DNA profiling mostly led to non-interpretable results. For the evaluation and interpretation of the data, buccal swab samples provided by drivers and co-drivers were analysed. The results and conclusions from DNA analyses and the declarations from the involved passengers were always concordant. Thus, molecular biological analysis of deployed airbags can help to determine the occupants positions within a vehicle (driver or passenger status) at the time of impact.