Fibroplasia in experimental protein deficiency: a study of fibroblastic growth and of collagen formation and resorption in the rat

Gradient chamber. A new method for migratory fractionation of inflammatory response in vivo

A new and simple method to study the inflammatory process in vivo using a diffusion-migration chamber is described. The influx of inflammatory elements into chambers was studied by light and electron microscopy. This gradient chamber (GC) was developed by substituting one of the filters of the classic diffusion chamber by a polyvinyl sponge cylinder. In the implanted chambers this plastic framework acts as a tridimensional gradient, through which the acute and chronic inflammatory processes migrate with different speeds and are thus divided into two distinct and widely separated waves. By delaying the overlapping of the first wave by the second, this bioassay allows a longer time for observation of the cell-matrix or cell-matrix-graft interaction during the first inflammatory wave and permits studies by methods such as immunocytochemistry, histochemistry or biochemical analysis.

The role of fibroblasts in the remodeling of periodontal ligament during physiologic tooth movement

Our findings indicate a cellular basis for the connective tissue remodeling which takes place during physiologic tooth movement. This cell is the fibroblast which is capable of synthesizing and degrading collagen simultaneously and, utilizing this ability, the orderly control of collagen remodeling within the periodontal ligament is possible. It is suggested that this cellular basis of connective remodeling will have a direct significance for orthodontic tooth movement once control mechanisms have been established.