Postmortem diagnosis of cerebral malaria

Human cerebral malaria is a frequent encephalopathy that occurs in the endemic tropical-subtropical zones. There are a smaller number of imported cases in continental zones where the diagnosis sometimes remains difficult to establish. Fifteen days after the death of a 36-year-old male French citizen in Africa, an investigation to determine the cause of death was conducted. Histologic examination of the brain permitted the diagnosis of cerebral malaria. Because of the popularity of overseas tourism and because this disorder may appear as "sudden death," these victims may be referred to a forensic pathologist. This case demonstrates the role a forensic pathologist may play in determining the cause of death in cerebral malaria.     

Correlation of the incidence of cocaine and cocaethylene in hair and postmortem biologic samples

Hair samples are useful as a matrix for drug testing because drugs can be detected in hair for longer periods than in blood or urine. The authors report a prospective comparison of the detection of cocaine and cocaethylene in routine postmortem biologic specimens to the detection of cocaine and cocaethylene in hair. The authors collected hair samples from various areas of the head in 53 autopsy cases, prepared them, and analyzed them by gas chromatography/mass spectrometry (GC/MS) for cocaine and cocaethylene. The authors compared the results of hair analysis with the results of toxicologic analysis performed on routine postmortem samples by enzyme multiplied immunoassay technique and GC/MS. Cocaine was found in either biologic fluids or in hair in 16 of 53 samples tested. Nine samples were positive for cocaine in both biologic fluids and hair. Five samples contained cocaine only in biologic fluids, and two contained cocaine only in hair. Cocaethylene was present in two cases. Drug screening of hair provides additional information in some autopsy cases, but the authors have not made hair analysis a routine practice. It may prove useful to save hair samples in all cases for later analysis if warranted by additional history or autopsy findings.     

Contents of Volume 19 (2000)

Volume Contents

Contents of Volume 19 (2000)     

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.     

Alternative primers for DYS391 typing: advantages of their application to forensic genetics

The amplification of the STR DYS391, using the primers described in the Genome Data Base (GDB: G00-365-251), shows not only an additional band to the Y-specific one in males with a size range of 26 bp less than those of DYS391 locus alleles, but also a polymorphic pattern in females in the same size range as the additional band observed in males. The DYS391 pattern in families reflects a Y-specific linked locus and also a polymorphic X locus with an X-linked pattern of inheritance. A first screening in the X homologous locus allowed the identification of five different alleles. Allele frequencies were explored in different population groups for both the Y locus and the homologous locus in the X chromosome showing a similar allele distribution pattern in the X and Y homologous loci. An alternative reverse primer was designed to amplify the Y-chromosome specific STR in order to improve the specificity and applicability of this system to forensic genetics. Comparative results of the amplification with the new and the previously described primers proved that with this new primer there is a substantial increase in the specificity of the amplification. Moreover, a smaller fragment is amplified with a size out of the range of the alleles of the other Y-STRs usually used in forensic applications, therefore simplifying its inclusion in multiplex systems.     

The use of supercritical fluid extraction for the determination of amphetamines in hair

A laboratory study interested in the analysis of human hair for drugs-of-abuse was conducted to determine if drugs could be detected and quantified from hair. Supercritical fluid extraction (SFE) techniques followed by GC-MS analysis were applied to extract amphetamines from hair. The group of amphetamines included methylenedioxyamphetamine (MDA), methylenedioxymetamphetamine (MDMA), methylenedioxyethylamphetamine (MDEA) and internal standard mephentermine (MP). To validate information on amphetamine use in hair, powdered hair samples free from drugs were collected and soaked in a known amphetamine standard solution. Authentic fortified case hair samples taken from known drug users known to have consumed amphetamines were also analyzed for amphetamine. Results from this study show that amphetamine use can be detected in spiked and authentic fortified human hair using SFE techniques for qualitative and quantitative reproducible results.     

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.     

Plastic bag asphyxia in southeast Scotland

Death resulting from plastic bag asphyxia has been recognized for >40 years, but relatively little is known about either its epidemiology or its pathophysiology. Over 15 years (1984-1998), 30 deaths were attributed to plastic bag asphyxia among the 14,560 autopsies performed in the Forensic Medicine Unit in Edinburgh. These 30 deaths involved 20 male and 10 female subjects, with an age range of 13 to 81 years. Eleven had some alcohol measurable in the blood, with four having levels >80 mg/dl. Only one individual appeared to have ingested a drug overdose, but inhaled substances within the plastic bag may have contributed to death in five cases. The absence of childhood accidental deaths may reflect successful preventive measures. The 3 accidental deaths involved adults (including 2 who died of autoerotic asphyxia), and the remaining deaths were 27 suicides. Of those who committed suicide, most (59%) had chronic psychiatric illness rather than chronic debilitating or terminal physical illness. In contrast with reports from the United States, publicity associated with "self-deliverance" did not result in an increased number of deaths from plastic bag asphyxia (4 deaths in this series). Analysis of the circumstances of all the deaths revealed them to be difficult to predict and hence prevent.