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G W COMSTOCK

Publications and source records attributed to G W COMSTOCK.

At least 19 recordsLinked to original sources

A COMPARISON IN THE UNITED STATES OF AMERICA OF TWO TUBERCULINS, PPD-S AND RT 23.

A comparison of PPD-S and RT 23 was carried out in three pairs of population groups. Tuberculin sensitivity was thought to have resulted, in one of each pair, almost entirely from infection with Mycobacterium tuberculosis, and in the other, from the diverse causes operating in the United States of America. Among persons with specific tuberculin sensitivity, 2.5 TU of RT 23 in a saline buffer containing Tween 80 were approximately equivalent to 5 TU of PPD-S in phosphate-buffered saline diluent. Among persons whose sensitivity appeared to have resulted from infections with organisms antigenically similar to the Battery strain of unclassified mycobacteria, 2.5 TU of RT 23 in Tween 80 gave considerably more reactions than 5 TU of PPD-S.

Alaska↗

A comparison of purified tuberculins in the south-eastern USA.

Simultaneous tests with 5 TU of the purified tuberculins PPD-S and RT 19-20-21 were given to 1617 schoolchildren in Muscogee County, Ga., and Russell County, Ala., USA. Contrary to findings reported from other places, in this area the qualitative differences between the two antigens were considerable. Low-grade tuberculin sensitivity, presumably nonspecific in nature, was evoked by RT 19-20-21 much more frequently than by PPD-S. Because of this finding, it is obvious that doses of tuberculins which give equivalent responses in one population may not give equivalent responses in other populations whose causes of tuberculin sensitivity may be quite different.

Humans↗