Homicide-suicide in Hong Kong, 1989-1998

This study provides the first systematic research of homicide-suicide (HS) in a Chinese society. Data were drawn from the HK Homicide Monitoring Data-base computer file derived from investigation and death reports held by the HK Police Force and the Coroner's Court. During the 10-year study period, 56 events involving 133 deaths were identified. The majority of offenders were males (75%) and most victims were female (64%). The mean age of offenders and victims were 41.9 and 32.3 years, respectively. Spouses and lovers comprised the majority of victims (46.4%) followed by child victims (36%). Most HS events were motivated by separation or termination of marital or sexual relations (39%), economic reasons (25%) and other domestic disputes (20%). The most frequent modes of killing were strangulation/suffocation (26%), stabbing/chopping (24%), followed by gassing/poisoning (14%) and falling from a height (14%). The commonest method of suicide was falling from a height (48%). It was followed by gassing/poisoning (22%) and strangulation/suffocation (13%). Depression (18.3%) was found to be the commonest mental disorder. Most offenders were from low-socio-economic background. Two-third were unemployed and 76.6% had 9 or less years of education. HS in HK were distinguished from those reported in the western literature in respect to the high relevance of economic factors, the absence of mercy killing between old couples, a higher percentage of pedicide-suicides and the infrequent use of firearms.     

Chromosome heteromorphisms and paternity testing

Most of the blood group systems have now been applied to paternity investigations. In a complicated case, an alleged father not excluded with blood group testing, could be excluded with only chromosome heteromorphisms. Chromosome heteromorphisms are inherited from parents to offspring as simple Mendelian laws. The authors' paternity testing is presented with the help of chromosome heteromorphism analysis.     

Homicide–suicide in Hong Kong, 1989–1998

This study provides the first systematic research of homicide–suicide (HS) in a Chinese society. Data were drawn from the HK Homicide Monitoring Data-base computer file derived from investigation and death reports held by the HK Police Force and the Coroner’s Court. During the 10-year study period, 56 events involving 133 deaths were identified. The majority of offenders were males (75%) and most victims were female (64%). The mean age of offenders and victims were 41.9 and 32.3 years, respectively. Spouses and lovers comprised the majority of victims (46.4%) followed by child victims (36%). Most HS events were motivated by separation or termination of marital or sexual relations (39%), economic reasons (25%) and other domestic disputes (20%). The most frequent modes of killing were strangulation/suffocation (26%), stabbing/chopping (24%), followed by gassing/poisoning (14%) and falling from a height (14%). The commonest method of suicide was falling from a height (48%). It was followed by gassing/poisoning (22%) and strangulation/suffocation (13%). Depression (18.3%) was found to be the commonest mental disorder. Most offenders were from low-socio-economic background. Two-third were unemployed and 76.6% had 9 or less years of education. HS in HK were distinguished from those reported in the western literature in respect to the high relevance of economic factors, the absence of mercy killing between old couples, a higher percentage of pedicide–suicides and the infrequent use of firearms.     

Simultaneous observation of catecholamine, serotonin and their metabolites in incised skin wounds of guinea pig.

In order to examine the vital reaction in wounds, catecholamines, serotonin (5-HT) and their metabolites in the incised skin wounds of guinea pigs were analyzed simultaneously by high-performance liquid chromatography (HPLC) using electrochemical detection (ECD). The principal changes in the levels of these compounds in vital wounds were as follows: a considerable decrease in norepinephrine (NE) content was observed 12-24 h after injury which persisted to at least 7 days. 3,4-Dihydroxyphenylacetic acid (DOPAC) decreased slightly for up to 30 min and then showed no significant difference compared with postmortem levels. Epinephrine and dopamine were barely detected by the HPLC-ECD method employed. 5-HT concentrations which showed an increase up to 24 h showed maximum levels 800 microns from the wound edge at 10 and 30 min after injury. 5-Hydroxyindoleacetic acid (5-HIAA) was significantly higher than the postmortem level over almost the entire period of these experiments. A 5-HIAA content of at least twice the postmortem level was observed 800 microns from the wound edge of a 10-min-old vital wound. Therefore, 5-HIAA is a likely candidate as a new marker for evaluating the vital reaction in wounds. The vital characteristics of NE, DOPAC, 5-HIAA and 5-HT in 10-min-old wounds persisted for up to 12 h at room temperature after death. These results suggest that the HPLC-ECD method used here is very useful for simultaneous examination of the vital reaction in wounds from the earliest to the later stages of the wound-healing period.     

Application of immunoblotting to serum protein phenotyping with reference to alpha 2HS-glycoprotein (AHS) typing of bloodstains

Sera and bloodstain extracts were subjected to isoelectric focusing in polyacrylamide gels. The focused proteins were transferred to nitrocellulose membranes by diffusion or electrophoretically, then allowed to react with specific antiserum and, after washing, with peroxidase-labeled anti-rabbit IgG. The immune complexes formed on the membranes were detected with 4-chloro-1-naphthol and hydrogen peroxide. Serum group-specific component, alpha 2HS-glycoprotein, the sixth and the seventh component of complement, factor 13B, and plasminogen could be phenotyped with high sensitivity. Bloodstains as old as 6 months could be correctly typed for alpha 2HS-glycoprotein by the blotting technique.     

Abuse of smoking methamphetamine mixed with tobacco: I. Inhalation efficiency and pyrolysis products of methamphetamine

Experiments of smoking methamphetamine in tobacco have been investigated. Inhalation efficiencies of methamphetamine into tar were 6 to 17% according to the additive amounts, suction volume, and intervals of smoking. Major pyrolysis products of methamphetamine in tar were identified as methamphetamine, amphetamine, phenylacetone, dimethylamphetamine, N-formyl-, N-acetyl-, N-propionyl-, and N-cyanomethyl-methamphetamine by the spectral analysis of infrared spectra (IR), mass spectra (MS), and proton magnetic resonance spectra (PMR), and comparison with the samples synthesized from authentic samples by one step. The largest pyrolysis product was N-cyanomethylmethamphetamine which is a new compound and easily metabolized to methamphetamine in the body. Methamphetamine itself transferred into tar was not so large, but the total active compounds in tar which would be metabolized to methamphetamine in the body were considerably larger.     

An ELISA using avidin-biotin complex for the determination of ABH group from saliva

The ABH group in a trace amount of saliva could be determined by an enzyme-linked immunosorbent assay (ELISA) using an avidin-biotin-peroxidase complex (ABC) technique. In this method ABH blood group substances as a solid phase are adsorbed to wells of a microtiter plate made of polystyrene. The primary antibody corresponding to the blood antigen adheres onto the wells, and reacts with the biotinylated secondary antibody. The previously formed ABC reagent is then added to the above wells, and finally the absorbance produced by the interaction of the peroxidase activity with a chromogenic substance is measured at 492 nm. This method proved to be clearly more sensitive for the detection of ABH blood groups in secretor-saliva than the conventional hemagglutination inhibition test. Also the ABH group of non-secretor-saliva could be easily determined by this method.     

Factor B subtyping in sera and bloodstains by isoelectric focusing and immunoblotting

The polymorphism of BF was investigated in 765 unrelated Japanese individuals by isoelectric focusing and immunoblotting. Besides five common subtypes three rare variants were observed. The allele frequencies were: BF*S = 0.8078, BF*FA = 0.1797, BF*FB = 0.0105, BF*Var. = 0.0020. The above method was successfully applied to subtyping BF in stored bloodstains. The determination limits were: at 4 degrees C 8 weeks, at room temperature 2 weeks and at 37 degrees C only 2 days after storage. The BF subtyping is of practical use in medicolegal individualization of unknown bloodstains.