A new HBsAg screening assay designed for sensitive detection of HBsAg subtypes and variants

The design of a new HBsAg screening assay, the Hepanostika HBsAg Ultra is based on the use of monoclonal antibodies raised against native wild-type HBsAg and reactive with HBsAg in which the common 'a'-determinant is modified by site-directed mutagenesis of four of the cysteine moieties. The design was checked using the same cysteine variants and samples from patients known to be infected with HBsAg variants. The results found were compared with other state-of-the-art commercial screening assays. The design of the Hepanostika HBsAg Ultra enabled detection of all variant HBsAg-positive samples in contrast to the other commercial assays. An additional 980 samples were tested to assess the specificity and sensitivity of the Hepanostika HBsAg Ultra. Screening of presumed negative serum and plasma samples resulted in a specificity of 100%. This makes the Hepanostika HBsAg Ultra the first screening assay with a design able to detect HBsAg variants with high sensitivity and specificity.

Epidemiological aspects of suicide among the young in selected European countries

Trends in reported suicide rates were analysed for the ages 5-24 years in 21 selected European countries in 1970-74 and 1980-84. In children the precision of the rates was found to be low though there appeared to be a trend to increased suicide in boys. In adolescent and young adult males, however, there was a definite increase in suicide over the period studied, and this was much more marked than in females, in whom the rates had declined in eight countries. The Belgian situation was investigated in detail. Increases were most pronounced in 20-24 year-old males. Around 1981, about half of youth suicides were committed by firearms and medicaments, and these methods showed the largest increases in risk. The estimated under-reporting error diminished with increasing age and over the past ten years. It was larger in females, but did not bias the trends substantially. On the aggregated level, youth suicide was found most strongly associated with indicators of anomie and social isolation. The relevance of these findings in the search for determinants and for preventive strategies is discussed.