Document GKanKqZYLJJKOdyb0wmwJqvEq

(LuJ Reprinted from the Archivee of Pathology April 1910, Vol. 09 Copyright 1970, by American Medical Auociolion i'lfOPtltari, ^ubUphtd JlLjf'f United Stotec of America 1/ r<Ferruginous Bodies*^ in Guinea Triigi s Fine Structure Produced Experiment&llyJProm Minerals Other Than Asbestos John M. C. 7>nr|i, PhPfCambridgr, England; and Paul Crou, MD, ----------- -- and Robert T, P. De Trtville, MD, Pittsburgh Electronmicroscope studies of ''ferruginous" bodies, produced in guinea pigs in response to fine glass fiber end ceramic aluminum silicate, have shown that the fine structure of these bodies is identical to that of asbestos bodies. All these bodies are produced intrecellulerly, mainly in giant cells. Their coating consists of small dense granules, approximately 60 Ang stroms in diameter, that probably represent ferritin or hemosiderin. This coating may be laid down as a single dense layer or as a series of variable layers. Usually all bodies are sepa rated from the giant cell cytoplasm by a dis tinct membrane, but in some of the older bodies this membrane is no longer present. ASBESTOS bodies were probably first observed by Fahr and Feigel in 1914,1 but they were not immediately associated with asbestos exposure. Fahr and Feigel called them strange crystals, and later in 1924, Cooke2 suggested that because of their beaded nature they might be fungi. Stew art and Haddow* realized that they were an integral part of the disease. They therefore coined the term "asbestosis body," but it was later understood that the number of bodies present was not directly related to the degree of lung fibrosis. For this reason the bodies became looked upon Accepted for publication Oct 17, 1069 From the Department of Pathology, Cambridge University, Cambridge, England (Dr. Davis), and the Industrial Hygiene Foundation of America, Inc.. Pittsburgh (Drv Cross and De Trevllle). Dr. Davis ts a member of the British Asbestosis Re search Council. Reprint requests to Department of Pathology, Cambridge University, Tennis Court Rd, Cam bridge, England (Dr. Davis). solely as an indication of asbestos expo sure. It was felt that they were produced in response to this mineral alone, and the term asbestosis body was changed to as bestos body. Gloyne, in 1932,4 demonstrat ed that each asbestos body contained a central core of asbestos dust surrounded by a coating which he thought contained iron and some protein material. The iron protein nature of the capsule was confinned by Beger2 and Sundius and Bygden. After the 1920's the industrial hazards of asbestos exposure were well known and resulted in most countries in strict hygienic regulations for factories and mines. It was believed, however, that the use of products containing asbestos was not dangerous to the general public and did not result in the liberation of harmful asbestos dust. This idea was repudiated by the find ings of Thomson et al in 1963,5 who re ported that structures very similar to asbestos bodies were present in the lungs of 30% of unselected autopsy cases from Cape Town. It seemed, therefore, that as bestos might be becoming a general urban hazard and studies were undertaken in other cities. These confirmed Thomson's results and bodies were found in 30% of autopsies from Miami, 43% from Pitts burgh, and 48% from Montreal.10 A more recent study in Pittsburgh 11 has found bodies in nearly 100% of autopsy cases. In all these reports, however, only a few bodies were found in each case and they appeared to result in no pathological changes in the lungs. Arch Path--Vol 89, April 1970 PI-AINTIFF'S EXHIBIT FD-14S2 SCF-FA-6400 S005 1448 PRODUCED BY FORD