Alcohol and inheritance : an experimental study / by F.M. Durham and H.M. Woods.

  • Durham, F. M. (Florence M.)
Date:
1932
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Alcohol and inheritance : an experimental study / by F.M. Durham and H.M. Woods. Source: Wellcome Collection.

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    16 TUBEKCULIN TESTS IN MAN ness is identical in both cases. Even so, as Baldwin, Petroiï & Gardner (1927 b) and Tytler (1930) point out, such sensitivity, in¬ duced by dead bacilli, may be associated with the formation of anatomic tubercle histologically similar to that following infection with living organisms. On the other hand, Baldwin (1911) had pre¬ viously shown that even the introduction of living tubercle bacilli would not result in cutaneous hypersensitiveness if they were separated from the tissues of the host by capsules. Krause (1916) summarized contemporary opinion concisely by the statement ' There is no cuta¬ neous hypersensitiveness [to tuberculin] without a focus (tubercle) although this might require careful search, and if the words 'under natural conditions ' are added, and possible cross-reactions within the species are excepted, this view is held by most workers to-day. The production both of true tuberculin hypersensitiveness and of anatomic tubercle by the injection of dead tubercle baciUi, i.e. without infection, raises the question whether or not a similar process occurs in nature by absorption of dead bacilli from the respiratory or the alimentary tract. The question is discussed by Krause (1925 b) with reference to human beings. He concludes that, while hypothetically possible, practically the contingency is open to grave doubt. If the possibihty that tuberculin sensitization arises in nature from the absorption of dead tubercle bacilli be dismissed, it is justifiable to take the presence of anatomic tubercle in human subjects at necropsy to indicate that infection (i.e. the invasion of the tissues by living bacilli) has taken place, and to conclude that under natural conditions tuberculin hypersensitiveness in man is the result of tuberculous in¬ fection. A cutaneous response to tuberculin is, however, obtainable under favourable experimental conditions without tubercle formation or actual infection, for the protein material obtained from the bodies of the tubercle bacilli may, as described above (p. 11), if suitably ex¬ tracted and injected in large quantities into a healthy animal, evoke slight though inconstant and transient cutaneous sensitivity to tuber¬ culin; and similar results have been reported by Zinsser & Tamiya (1926) and Bohart (1930) after repeated intraperitoneal injection of relatively large amounts of Old Tuberculin or of tuberculin protein fractions. Sensitivity is more marked if an autolysate of tubercle bacilli is used, as in McJunkin's experiment (p. 11). Nevertheless, Baldwin, Petrofif & Gardner (1927 a) hold the view that the transient cutaneous response to tuberculin obtained in uninfected animals is distinguishable from true tuberculin hypersensitiveness, which they consider is only evoked by living or dead bacilli. Although in the natural state characteristic sensitivity to tuberculin appears, with a few possible exceptions, to be constantly associated with ' tubercle tissue ', and its experimental production without this formation is open to question, it must not be concluded that tubercle tissue, as such, is an essential causative factor in the production of hypersensitiveness. Tytler (1930) points this out and cites some of the objections to such a view. It is at present wiser merely to consider that