Development of a simulation model to assess the impact of contamination in casework using STRs

Because contamination is usually tube-specific, negative controls cannot give assurance that an associated batch of extracted casework material is contaminant-free. However, it is possible to use them to predict the level of overall (undetected) contamination that is processed by an operational DNA unit. A MATLAB-based program was used to combine results of negative controls with actual casework DNA profiles to assess the probability that laboratory contaminants will give rise to reportable profiles (along with their likelihood ratios). Using data from an operational DNA unit as an example, it was demonstrated that the risk is inextricably linked to guidelines used to interpret DNA profiles. We have demonstrated how computer-based models can predict the levels of contamination expected in the process and, in addition, how the process can be made more robust by changing reporting guidelines. There is a need to compare DNA profiles against staff and plasticware elimination databases in order to determine sources of contamination. The likeliest outcome of a contamination event is false exclusion.     

The possible influence of micro-organisms and putrefaction in the production of GHB in post-mortem biological fluid

In recent years, the post-mortem production of the drug of abuse gamma-hydroxybutyric acid (GHB) in biological fluids (e.g. blood and urine) has caused various interpretative problems for toxicologists. Previously, other researchers have shown certain microbial species (Pseudomonas spp. and Clostridium aminobutyricum) possess the necessary enzymes to convert GABA to GHB. A preliminary investigation involving putrefied post-mortem blood indicated there was no observed relationship between "endogenous" GHB concentrations and concentrations of common putrefactive markers (tryptamine and phenyl-2-ethylamine). Microbiological analysis identified the presence of various micro-organisms: Clostridia spp., Escherichia coli, Proteus vulgaris, Enterococcus faecalis and Aeromonoas spp. Equine plasma, human blood and urine samples were inoculated with these and an additional micro-organism (Pseudomonas aeruginosa) and incubated at 22 degrees C for 1 month. Following comparison with control samples and pre-inoculation concentrations, the data indicated an apparent production of GHB in unpreserved P. aeruginosa inoculated blood (2.3 mg/l). All other fluoride-preserved and unpreserved samples (including controls) had GHB concentrations <1mg/l. Although this concentration is lower than is typically associated with "endogenous" post-mortem GHB concentrations, this paper proposes a potential microbial production of GHB with time.     

FISCAL STRESS AND HEALTH POLICY IN THE A.C.T.*

Abstract: Since 1981, the financing of the‘ ACT has been subject to five inquiries by the Commonwealth Grants Commission. These inquiries have incorporated the ACT into the fiscal equalisation process between Australian states and territories. and have significantly affected the ACT'S general revenue grants from the commonwealth. The inquiries produced evidence of generous commonwealth funding of the ACT compared with the other states. This funding has given rise to “over-spending” on service provision by the ACT government. The ACT government is not currently responsible for all identified “over-spending”. being buffered to some extent by transitional allowances recommended by the Grants Commission. The ACT government is, however, experiencing fiscal stress for the “overspending” for which it is responsible. This stress is expected to increase in the future as the ACT government comes to bear the full burden of all “overspending”. A significant cause of the “over-spending” identified by the Grants Commission was health services expenditure. This situation has raised a number of interesting questions. Is the “overspending” on health a conscious policy decision to produce a higher quantity/quality combination of health services in the ACT? Or does it represent inefficiency? What policy options are appropriate in view of the “over-spending” on health? This paper addresses these questions using data from the Grants Commission inquiries and a recently released study of hospital utilisation and costs in Australia. It is concluded that, at least with respect to public hospitals in the ACT. excessive stafting is the primary cause of “over-spending”. There is little evidence to support an argument that this “over-spending” is resulting in superior health outcomes for ACT citizens.