Between antinomy and symmetry. Architectural drawings of presentation and comparison in the XVI Century

As part of a wider enquiry on the historical typologies of architectural representation, this essay addresses a classification of XVI century architecture drawings that exploit the presence of one or more symmetry axes in the represented building. This kind of split drawings have never been studied as a specific group of works inspired by the specific peculiarities of buildings but only occasionally to mark a new role of architectural drawing. Actually, symmetry combined to orthogonal projections allowed the development of graphic procedures with peculiar goals. Initially restricted into the circle of artist and his assistants, they were gradually addressed to a wider audience. They show a diffuse attitude to draw or copy only half-building; to match interior with exterior; to combine distant elements from a building; to compare alternatives; to confront geometry and perspective effect. All of these practices deeply changed the visual code of architects, evolved the relationship between the artist and commitment; and improved the ability of ordinary people to understand partial and analytical drawings

Immunohistochemical demonstration of FC receptors in rat tissues using immune complexes as ligand

To demonstrate the presence and localization of Fc receptors, rat liver cryostat sections were incubated with heterologous and autologous immune complexes (ICx) and immunoglobulin (Ig) aggregates. Binding was demonstrated using the immunoperoxidase technique. Autologous and heterologous ICx as well as aggregates from human and rat Ig appeared to bind to the sinusoidal wall. ICx bind in preference to aggregates. Monomeric Ig and aggregated Ig from swine and rabbit did not bind. The results demonstrated that ICx and rat and human Ig aggregates were bound via an Fc receptor. This Fc receptor was still intact in livers from carbontetra chloride and galactosamine treated rats. The receptor could also be demonstrated on spleen macrophages and on kidney interstitial cells. This method turned out to be an useful functional histochemical method to localize Fc receptors and to demonstrate their affinity and species specificity in tissue