Norimasa Miyakogawa

Experimental Cholesterol Granuloma Histopathological and histochemical studies

The authors have induced experimentally middle-ear effusions and cholesterol granulomas one month and later after tubal obstruction in squirrel monkeys. Cholesterol crystallization has occurred frequently in the middle-ear fluids of three-and six-month-animals, and, typical cholesterol granulomas were noted in four of the eight middle ears of six-month-monkeys. The shape and size of the cholesterol crystals were variable, depending upon the surrounding cells of fluid. In middle-ear effusion, the crystals formed rather large rectangular structures, which tended to become smaller and thinner, as the granulomas developed. The granuloma containing cholesterol crystals was rich in various oxidative and hydrolytic enzymes. The large cells surrounding the crystals show intense-to-strong enzyme activity and probably play a phagocytic role in the developing and healing processes of the granuloma.

The fiber arrangement of the pathological human tympanic membrane

ZusammenfassungDas pathologisch veränderte menschliche Trommelfell (Perforation, Verdickung oder Vernarbung) zeigt in der mittleren Zone der Pars tensa eine deutliche Veränderung des Faserverlaufes. Zwischen den regelrecht angeordneten radiären und zirkulären Fasern sieht man zahlreiche ungeordnete Fasern, die zur Bildung von Bündeln neigen. Es wird also während des Heilungsprozesses einer entzündeten Lamina propria des menschlichen Trommelfelles die normale Faseranordnung gestört.SummaryRemarkable morphological changes of the fiber arrangement was observed in the middle lamina propria of the pathological human tympanic membranes. These changes were present mainly in the middle zone of the pars tensa. There were several fibers running in entirely different directions among the regularly arranged radial and circular fibers. These abnormal fibers had a tendency of forming fiber bundles of varying sizes and lengths. It is stressed that the normal fiber arrangement was undoubtedly disordered in the healing process of the inflamed middle lamina propria of the human tympanic membrane.