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O G HANSEN

Publications and source records attributed to O G HANSEN.

6 recordsLinked to original sources
PubMed1964

ASSESSMENT OF THE POTENCY OF TUBERCULIN IN HUMANS AND GUINEA-PIGS.

The biological effects of tuberculin in an organism infected with tubercle bacilli are due to an unknown number of different substances, which are present in varying concentrations in different tuberculin preparations. Consequently, the response to tuberculin tests with various products is likely to vary with the biological material, the test technique, the tuberculin dose, etc., and potency estimates of tuberculin products will depend to a considerable extent on how the assessment is made. The present paper describes an experiment in which this dependence was demonstrated in the case of two purified protein derivative tuberculin preparations (RT 23 and PPD-Weybridge). The potency ratio of these products was found to vary widely according to whether it was determined in humans by the Pirquet test or in guinea-pigs by the Mantoux test, and the authors therefore conclude that tuberculin products must be assessed under the conditions in which they will subsequently be used.

Animals↗
PubMed1964

CO-OPERATIVE STUDIES OF METHODS FOR ASSAY OF BCG VACCINE. WORLD HEALTH ORGANIZATION.

Co-operative studies-co-ordinated by the WHO Tuberculosis Research Office, Copenhagen- of methods for the assay of BCG vaccine were undertaken in 1959 by eight laboratories in seven countries. All the laboratories received the same four vaccines; seven of them carried out viability counts by formally standardized techniques and one made estimations of the total number of bacilli per millilitre by its own technique. In addition, some laboratories assayed the vaccines by special methods, such as examination of germination capacity, distribution of clumping, and uptake of (14)C-labelled acetate, mouse-protection tests and tests of the ability of the bacilli to multiply in mice.The data obtained are presented here in full, together with a detailed statistical analysis. The results are not immediately encouraging: the viability counts for the same vaccines differed distinctly from laboratory to laboratory and the variability of the individual counts within the same laboratory was mostly much larger than would have been expected theoretically. However, it appears that the relatively sophisticated statistical methods used, if applied to routine laboratory findings, might be of considerable value in pin-pointing the most significant sources of experimental error in a given laboratory. It is also felt that this extensive collection of data may be useful as a reference source whenever a particular aspect of BCG standardization is in question.

Animals↗