The biological assay of testicular diffusing factor

The Presence of Diffusing Factor among the Metabolites of Aerobic Micro-organisms

“…It will be noticed that there is a close linear relation between the second, third, and fourth points on the second curve and that the departure from linearity of the first and fifth points is what would be expected if the usual sigmoidal relation were expressed by the curve. As it has been shown (Bacharach, Chance, and Middleton, 1940) that within the limits involved bleb area is lineally related to the logarithm of the amount of diffusing factor used, it follows that the amount produced in this culture was lineally related to time of incubation.…”

“…We wish at the outset to make it clear that our references to "diffusing factor" and "diffusing activity" are to the substance that, in the simple but lucid definition of McClean and Morgan (1933), " dramatically increases the permeability of the skin to injected fluids and particles." All our tests, qualitative or quantitative, have been carried out by the procedure described elsewhere (Bacharach, Chance, and Middleton, 1940) for testicular diffusing factor (t.d.f. ): the results of these tests are not necessarily the same as would have been obtained by different methods.…”

“…Our method is based on the measurement of " blebs" produced in the skin of shaved rabbits after intradermal injection of the test solution. Full details have been published elsewhere (Bacharach, Chance, and Middleton, 1940), and it is here necessary only to indicate the quantitative limitations of the restricted tests reported below. Between bleb areas of 4 and 7 sq.…”

“…cm. In,these estimates the calculation of variance is based on the heterogeneous groups used in the experiments described by Bacharach et al (1940)* ; this is certainly an overestimate when doses are distributed so as to counteract the effect of differences in sensitivity of different animals. A fairer estimate of variance can be calculated from the differences between replicate blebs produced by the same dose on one animal, and this estimate may be used in assessing the significance of the difference between mean values of bleb areas obtained under our conditions of test.…”

A New Anti‐inflammatory Test, Utilizing the Chorio‐allantoic Membrane of the Chick Embryo

“…test " (Long & Miles, 1950), "the ultra-violet erythema test " (Wilhelmi & Domenjoz, 1951), " the granuloma pouch test " (Selye, 1953), " the pleural exudate test " (Holtkamp, Wang & Doggett, 1958), and various modifications of these methods (Buttle, D'Arcy, Howard & Kellett, 1957;Bush & Alexander, 1960;Tanaka, Kobayashi & Miyake, 1960;Newbould, 1963;and Meli, Smith & Wolff, 1964). In addition, various capillary permeability tests utilizing the spread of dyes through tissue have been introduced (Bacharach, Chance & Middleton, 1940; Seifter, Baeder & Begany, 1949) and also tests involving the anaphylactic reaction (Smith & Humphrey, 1949;Ungar, Damgaard & Hummel, 1952).The present study describes an inflammatory response induced on the chorio-allantoic membrane of the eight-day-old chick embryo, and its reduction by known anti-inflammatory agents, both steroidal and non-steroidal. These agents, all of which were effective in this test, included betamethasone, hydrocortisone, phenylbutazone, chloroquine, indomethacin and sodium salicylate.…”