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Several biopsies of human marginal gingiva were collected from clinically healthy and from slightly inflamed sites. The biopsies from one given site were divided and treated as follows: one portion was immediately fixed and used as a reference; the others were incubated for two hours either in culture medium alone, or in the same medium with different concentrations of elastase purified from human polymorphonuclear leukocytes. The biopsies were theft fixed and examined by electron microscopy. It was found that elastase caused an enlargement of the intercellular spaces of the oral gingival epithelium, interruptions of the basement lamina, and loss of collagen in the underlying connective tissue. Biopsies collected from severely inflamed sites were also studied in the electron micro- scope. Some of the ultrastructural alterations observed in these inflamed tissues were similar to those experimentally induced by elastase. [ABSTRACT FROM AUTHOR]

An ultrastructural study on human gingival made it possible to localize acid phosphatase in polymorphonuclear leucocytes, bacteria and to a lesser degree in histiocytes. The polymorphonuclear leucocytes with autophagic bodies, the histocytes contained and ruptured lysosomes as well as phagocytic vacuoles with engulfed bacteria. The surface of leucocyte cell membranes sometimes presented a positive enzymatic reaction. Large bodies, rich in acid phosphatase were observed in mast cells. In the epithelial cells scattered fine lead precipitates were noted and the epithelial nuclei sometimes reacted positively. In Gram positive bacteria, acid phosphatase was localized between the cytoplasmic membrane and the cell wall, whereas in Gram negative bacteria a positive reaction was observed in the outer layers of the cell wall. Bacteria without cell walls were surrounded by a lead precipitate. In addition, lead stainings were located in the bacterial cytoplasm. The major acid phosphatase activity seemed to be related to the leucocytes and the leucocytes and the micro-organisms. [ABSTRACT FROM AUTHOR]

This article informs about the forthcoming symposium "European Symposium on Borderland Between Caries and Periodontal Disease. Applications of Molecular Science." It will take place in Geneva, Switzerland, on January 25 and 26, 1990. The central theme of the symposium will be the applications of molecular science to the study of caries and periodontal disease. The article also presents the names of eminent speakers who are expected to participate in this symposium. It also provides contact address for acquiring further information about the symposium.

The article presents information about the book "Monographs in Oral Science," edited by H.M. Myers. The book is a monograph on human gingival fluid. In its introductory section, the book discusses problems of permeability of junctional and oral sulcular epithelia. One chapter is devoted to recent concepts on the mechanism of gingival fluid production, especially at the onset of the inflammatory reaction. The book proposed a new method to collect and evalute human crevicular fluid. A large section of the book is devoted to the composition of gingival fluid.