The role of certain sections of the central nervous system in the genesis of sudden death]

Hypothalamic and hippocampal lipid composition in sudden death from coronary heart disease is studied. Thin-layer chromatography was the main method of biochemical analysis. Disorders in the lipid component of hippocampal cytostructures involved mainly the cholesterol fractions. Metabolic disorders in the hypothalamus involved the phospholipid metabolism. The above-mentioned biochemical changes were paralleled by ultrastructural abnormalities. Analysis of the data demonstrates a probable metabolic basis of a central mechanism of sudden cardiac death.     

Screening for barbiturates in vitreous humor by the EMIT-st serum enzyme immunoassay

In 16 medical examiner's cases, which were found to be barbiturate-positive by thin-layer chromatographic screening of the liver, blood barbiturate concentrations were determined by gas chromatography. The corresponding vitreous humor samples were screened by the enzyme multiplied immunoassay technique, the EMIT-st serum barbiturate assay. By using the recommended dilution for detecting serum barbiturates, it was possible to detect barbiturates in vitreous humor at a toxic concentration. By using one fourth the amount of diluent, the barbiturates could be detected also at a therapeutic concentration. The EMIT-st assay proved to be useful in the screening for barbiturates in vitreous humor, a material that is readily available in forensic toxicology.     

An investigation into the use of calculating the first derivative of absorbance spectra as a tool for forensic fibre analysis.

A range of fibre samples was measured using J&M MSP400 and J&M MSP800 microspectrophotometers across the visible and UV/visible wavelength ranges respectively. The first derivative of the absorbance spectra was then calculated and studied. When the absorbance spectra produced for some samples were broad and featureless, the first derivative spectra provided more points of comparison that facilitated discrimination. For many of the samples, calculating the first derivative did not result in any additional discrimination due to the high number of points of comparison present in the absorbance spectra. However, for the samples that exhibited a high level of intra-sample colour variation (e.g. through uneven dye uptake common in cotton and wool, etc.), which was evident in the absorbance spectra, the associated first derivative spectra highlighted this variation between the fibres and could potentially have resulted in false exclusions. The results show that whilst calculating first derivative can be a useful aid in the comparison of spectra, a high degree of caution is required when applying this method to fibres which exhibit a large intra-sample variation in colour.