Abstract: A power transmission system transmits rotative power from a driver pulley to a driven pulley through a toothed belt. The tooth tips (27b) and/or tooth bottoms (27c) of teeth of at least the driven pulley (10) lie in a plane including a central axis l.sub.2 of rotation of the driven pulley and are inclined with respect to the central axis l.sub.2. When the toothed belt (14) is operated to transmit the rotative power, the position where teeth of the pulley (10) and teeth of the toothed belt (14) start meshing with each other is progressively displaced, thus lowering the level of impact sounds produced when the teeth mesh with each other.

Abstract: A composition for oral application comprises a nonspecific .gamma.-globulin as an effective ingredient for preventing Bacteroides gingivalis from colonizing in the mouth.

Abstract: A reagent for the enumeration of oral gram-negative bacteria, such as Bacteriodes melaninogenicus, Capnocytophaga sp. and Eikenelia corrodens, by an indirect fluorescent antibody method is provided which utilizes an unlabelled antiserum to oral gram-negative bacteria and a fluorescent conjugated antibody obtained by immunizing an animal of a different species than the antiserum with .gamma.-globulin of an animal of the same species as the antiserum. A sample containing oral gram-negative bacteria to be enumerated is treated with the antiserum and the reaction product obtained is then treated with the fluorescent conjugated antibody to enumerate the bacteria in the sample by observing under a fluorescent microscope.