Document mqB1rp5nEbax9Lnr3wNxgvr9g

FILE NAME: Z//E DATE:D DOC#: /E DOCUMENT DESCRIPTION::ZEZ>Z ZDWZZZ'W -Industrial Hygiene Digest ~ i I May, 1954 549 Further Thoughts on Silicosis. P. Heffernan. Tubercle 34, 246-249 (Sept. 1953). The author rejects the solubility theory of silicosis and propounds :.nstead a surface valency theory. The structure of freshly fractured silica is held to possess chemical surface activity with ability to coagulate and fix large masses of organic material. The freshly fractured ends of asbestos are :;rnstulated to possess the same activity; hence asbestosis. Freshly powdered aluminum forms a protective coating over the silica particles to render th.em !"iarmless. Further details are given, but the discussion is entirely theoretical. -- Cond. from Bull. Hyg. I 550 The Nature oi Lesions Caused by Asbestos and Mica in Experimental ~)neumoconiosis in Guinea Pigs. A. S. Ramaswamy, D. S. Venkatesh, ~- ~nct R. Rama Rao. J. Indian Inst. Sci. 35, Sect. A, 319-331 (Oct.1953). Guinea pigs were subjected to intratracheal injections of mica and L~sbestos dusts. Stress is laid on the development, after long periods, of lesions in other organs besides the lungs, especially in the adrenal glands. Mica (iust was found to lead to some degree of nodular formation in the lungs, but ~he asbestos dust set up diffuse fibrosis only. These differences are por- 'i ~rayed in a series of photcrnicrographs. Mica induced hypertrophy of the ad- I re11al cortex with extensive foamy disintegration of the cortical cells; asbestos ~nduced lesser changes, but small areas of necrosis were occasionally found :n the zona fasciculata and zona reticulata. In a theoretical discussion, the :~uthors attempt to draw a relation between the atomic structure of mica and ~sbestos and the pathological lesions in the lungs and other organs. Their heory, however, leaves many points unexplained. --Cond. from Bull. Hyg. 551 Action of Testosterone in Guinea Pigs Infected with Koch's Bacillus with Reference to Therapy of Silica-Tuberculosis. A. Raule, L. Pecchiai, and R. Grisler. Med. lavoro 44, 475-484 (1953). Italian with English summary. Of 20 guinea pigs infected with 1 mg. of tubercle bacilli suspended in 1.1ater 10 received daily 0. 5 mg. testosterone propionate. The treated animals showed less reaction in the lymph glands at the site of injection than in other parts and the granulomata were less developed. The sclerotic scar tis sue which replaces granulomata appeared in the controls to be hyperplastic, but not in tne treated animals. -- Chem. Absts. Of all U.S. business firms- -slightly over two million- -only 5 % have 20 or more employees, and only 25 % have four or more employees. - - Supervisor's Personnel Newsletter Bureau of Business Practice, Dec. 7, 1953 29.