The statistical variability of blood alcohol concentration measurements in drink-driving cases

Like many other places in the world, Hong Kong has drink-driving legislation which prohibits a driver from having in his blood alcohol exceeding a prescribed limit while in control of a motor vehicle. The accuracy of measuring this alcohol concentration is obviously of prime concern as an erroneous result can avert the administration of justice. The common practice is to deduct all errors from the measured value and compare the deducted value with the prescribed limit, so that the benefit of all errors of the measurement is given to the driver. It is therefore important for any laboratory responsible for measuring blood alcohol concentrations to identify and quantify all errors associated with the measurement. The present study examined 900 blood alcohol determinations carried out by the Hong Kong Government Laboratory (HKGL) on cases of suspected drink driving. The determinations were performed by 5 different analysts with two different sets of instruments during 1995-1997. Statistical analysis indicated that the instruments had no bearing on the random error or variability and that even though analyst was a significant factor on variability, the deviation from the mean so caused was only 0.3% and of no practical significance. When the systematic error introduced by the tolerance limits of the certified alcohol standards (purchased from the Laboratory of Government Chemists, UK) was taken into account, the total uncertainty (random plus systematic errors) of an alcohol determination at 99.5% confidence level was found to be 4%. It is recommended that laboratories engaged in blood alcohol determination should adopt similar statistical treatment of their analytical results to find out the error and to ensure that the results are independent of analyst and instrument used.     

Unusual infant death: dog attack or postmortem mutilation after child abuse?

An unusual form of fatal child abuse is reported in which investigations by the police and the medical examiner were able to distinguish blunt force head trauma followed by postmortem dismemberment from a fatal dog attack. A discussion of the approaches used to ascertain the correct diagnosis is presented, as well as an overview of dog attacks on humans.     

Swiss Caucasian population data for the STR loci D2S1338 and D19S433 using the AmpFISTR SGM plus PCR amplification kit

Allele and genotype frequencies for the ten STR loci D3S1358, VWA, D16S539, D2S1338, D8S1179, D21S11, D18S51, D19S433, TH01, FGA were determined in a Swiss Caucasian population sample (n=206) using the AmpFISTR SGM Plus Amplification kit. Electrophoresis was carried out on an ABI PRISM CE 310 Genetic Analyzer instrument. Previously, allele frequencies were published for the 13 STR loci D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820, THO1, TPOX, CSF1PO and D16S539 for the same samples (n=206) amplified with the AmpFISTR Profiler Plus and Cofiler PCR Amplification kits. Since the results for the eight loci D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, THO1, D16S539 shared between the AmpFISTR SGM Plus, Profiler Plus and Cofiler PCR Amplification kits already are published, only the allele frequencies for the two STR loci D2S1338 and D19S433 are reported in this paper. The two loci meet Hardy-Weinberg expectations. In addition, there is little evidence for association of alleles among the 15 loci (amplified with the Profiler, Cofiler, and SGM Plus amplification kits). The allelic frequency data can be used in forensic analyses to estimate the frequency of a multiple STR locus DNA profile in the Swiss population.     

Delimitation of the time of death by immunohistochemical detection of thyroglobulin

To improve the possibilities to delimit the time of death after longer laytime it was examined if this is possible by immunohistochemical detection of thyroglobulin. The results show that in our examination material the colloid and the follicular cells of the thyroid glands of up to 5-day-old corpses produce a positive immunoreaction towards thyroglobulin in all cases whereas none of the corpses older than 13 days show such a reaction. This means that in case of a negative immunoreaction the time of death can be assumed to lie more than 6 days before the autopsy. The fact that a negative immunoreaction occurs consistently after 13 days leads to the conclusion that when thyroglobulin has been stained in a specimen, the death of the respective person must lie a maximum of 12 days earlier, whereby these time-limits may change in considerably different surrounding conditions.     

Mass screening in low-income populations: the challenges of securing diagnostic and treatment services in a national cancer screening program

Funding for many mass screening programs for low-income and uninsured populations provides resources for screening tests, yet only rarely does it provide coverage for necessary follow-up diagnostic and treatment services. The National Breast and Cervical Cancer Early Detection Program (NBCCEDP), a federally funded initiative that provides cancer screening to low-income uninsured and underinsured women, covers some diagnostic follow-up tests and no treatment services. We conducted in-depth case studies of seven state programs participating in the NBCCEDP to investigate the strategies and approaches being used to secure diagnostic and treatment services. The results suggest that the program relies on a patchwork of resources--at state and local levels--to provide diagnostic and treatment services. This includes a number of components of local safety nets, all of which are unstable and have uncertain futures. Public health disease-screening initiatives need to reconsider the feasibility of continued reliance on case-by-case appeals to the local safety net for diagnostic follow-up and treatment services.     

Simultaneous determination of THC-COOH and THC-COOH-glucuronide in urine samples by LC/MS/MS

A fast method using liquid-liquid extraction and HPLC/tandem-mass spectrometry (LC/MS/MS) was developed for the simultaneous detection of 11-Nor-Delta(9)-tetrahydrocannabinol-9-carboxylic acid beta-glucuronide (THC-COOH-glucuronide) and 11-Nor-Delta(9)-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) in urine samples. This highly specific method, which combines chromatographic separation and MS/MS analysis, can be used for the confirmation of positive immunoassay results even without hydrolysis of the sample or derivatisation of extracts. Liquid-liquid extraction was optimised: with ethylacetate/diethylether (1:1, v/v) THC-COOH-glucuronide and THC-COOH could be extracted in one step. Molecular ions of the glucuronide (MH(+), m/z 521) and THC-COOH (MH(+), m/z 345) were generated using a PE/SCIEX turboionspray source in positive ionisation mode; specific fragmentation was performed in the collision cell of an API 365 triple-quadrupole mass spectrometer and yielded major fragments at m/z 345 (for THC-COOH-glucuronide) and m/z 327 as well as m/z 299 for both cannabinoids. Chromatographic separation was performed using a reversed-phase C8 column and gradient elution with 0.1% formic acid/1 mM ammonium formate and acetonitrile/0.1% formic acid. Retention times were 22.2 min for the glucuronide and 26.8 min for THC-COOH. After enzymatic hydrolysis of urine samples with beta-glucuronidase/arylsulfatase (37 degrees C, 5 h), THC-COOH-glucuronide was no longer detectable by LC/MS/MS in urine samples. However, the THC-COOH concentration was increased. For quantitation of THC-COOH, THC-COOH-D(3) was added to the urine samples as internal standard prior to analysis. From the difference of THC-COOH in the native urine and urine after enzymatic hydrolysis, molar concentration ratios of THC-COOH-glucuronide/THC-COOH in urine samples of cannabis users were determined and found to be between 1.3 and 4.5.     

Numerical density of delta-opioid receptor expressing neurons in the frontal cortex of drug-related fatalities

In animal experiment and in cell culture, chronic morphine treatment has been followed by a reduction as well as an increase of the delta-opioid receptor (OR) number. The present postmortem morphometric study of morphine-related fatalities of drug addicts (n=12, 22-35 years old, with blood unconjugated morphine levels from 27.1 to 407 ng/ml, m.v. 176.9 ng/ml) versus a non-addicted control group (n=13, 10-44 years old) is intended to examine whether chronic opiate exposure also affects the numerical density of deltaOR expressing neurons in the human neocortex (area 10 according to Brodmann (Vergleichende Lokalisationslehre der Grosshirnrinde (1909) Johann Ambrosius Barth, Leipzig)). For the immunohistochemical procedure, vibratome sections (100 microm) were incubated with a monoclonal antibody against the deltaOR diluted 1:100, and immunoreactive sites were visualized using an immunoperoxidase protocol. The numerical densities of OR expressing and Nissl-stained neurons were assessed morphometrically (camera lucida drawings). In both collectives, the anti deltaOR immunoreactivity was predominantly localized in pyramidal neurons of layers (L) II/III and V as well as in round and ovoid neurons of L VI. In the drug-related fatalities, the density of neurons expressing deltaOR protein amounted for 2515+/-240/mm(3), in the control group for 2616+/-204/mm(3), thus displaying no statistically significant difference. These findings go along with the binding behavior of opioid ligands in postmortem brains of heroin addicts revealing similar receptor densities and affinities in the control subjects and addicts.