Henry W. Scherp

Lysis of Collagen by Human Gingival Bacteria.

Summary Collagenolytic activity was demonstrated in mixed cultures of gingival bacteria from 13 of 19 individuals with chronic marginal gingivitis but from only 3 of 21 individuals with clinically normal gingivitis. This difference is statistically valid. The use of native collagen as a substrate, in the form of tendon, and the determination of the liberation of peptides containing hydroxyproline as an indication of collagenolysis are believed to make the results significant for the situation in vivo. Consequently, it is inferred that gingival bacteria may contribute to the destruction of the collagenous fibers of the periodontium seen in periodontitis.

Protective Value of Immune Rabbit Serum and Its Globulin Fraction Against Experimental Murine Infection with Hemophilus pertussis

Summary Immune rabbit serum, injected intraabdominally into mice, protects them against experimental infection produced by the intranasal inoculation of Hemophilus pertussis. By precipitation in 50% saturated sodium-sulfate solution (37°C), a globulin fraction was prepared which had essentially the same protective capacity and agglutinating titer as the original serum, but only one-third of its content of protein.