Document zz8LjJoZrb5DRyeoz0rwNEZpg

FILE NAME: Asbestos in India (IND) DATE: 1954 May DOC#: IND002 DOCUMENT DESCRIPTION: Journal Abstract - Nature of Lesions Caused by Asbestos & Mica in Experimental Pneumoconiosis in Guinea Pigs Industrial Hygiene D igest May, 1954 549 Further Thoughts on S ilic o s is . P . H effern an . Tubercle 34, 246-249 (Sept. 1953). The author rejects the solubility theory of silico sis and propounds instead a surface valency theory. The structure of freshly fractured silica is held to p o ssess chem ical surface activity with ability to coagulate and fix large m asses of organic m aterial. The freshly fractured ends of asbestos are postulated to p ossess the sam e activity; hence a sb e sto sis. F resh ly powdered aluminum form s a protective coating over the silica p articles to render them harm less. Further details are given, but the discussion is entirely theoretical. -- Cond. from Bull. Hyg. 550 The N ature o i L e sio n s C aused by A sb e sto s and M ica in E xp erim en tal Pneum oconiosis in Guinea P ig s. A. S. R am aswam y, D. S. Venkatesh, md R. Rama Rao. J. Indian Inst. Sci. 35, Sect. A, 319-331 (Oct. 1953). V Guinea pigs w ere subjected to intratracheal injections of m ica and asbestos dusts. Stress is laid on the developm ent, after long periods, of lesion s m other organs besides the lungs, especially in the adrenal glands. Mica aust was found to lead to som e degree of nodular form ation in the lungs, but the a sb estos dust set up diffuse fib ro sis only. T hese d ifferen ces are p or trayed in a series of photom icrographs. M ica induced hypertrophy of the ad renal cortex with extensive foam y disintegration of the cortical cells; asbestos induced le sse r changes, but sm all areas of n ecrosis w ere occasionally found in the zona fa scicu la ta and zona reticu lata. In a th eoretica l d iscu ssio n , the authors attem pt to draw a relation between the atom ic structure of m ica and asbestos and the pathological lesion s in the lungs and other organs. Their theory, how ever, leaves many points unexplained. - -Cond. from Bull. Hyg. ^1 Action of T estosterone in Guinea P igs Infected with Koch's B acillus with R eferen ce to T herapy of S ilic o -T u b e r c u lo s is . A . R au le, L,. P e c c h ia i, and R. G r isle r . M ed. lavoro -44, 4 7 5 -4 8 4 (1953). Italian w ith E n glish su m m ary. Of 20 guinea pigs infected with 1 m g. of tubercle bacilli suspended in 'vater 10 received daily 0 .5 m g. testostero n e propionate. The treated anim als showed le ss reaction in the lym ph glands at the site of injection than in other parts and the granulom ata w ere le s s d eveloped. The sclero tic scar tissue which replaces granulom ata appeared in the controls to be h yperplastic, but not in the treated an im als. -- Chem. Absts. Of all U. S. business firm s--slig h tly over two m illion --on ly 5% have 20 or m ore e m p lo y e e s, and only 25% have four or m ore em ployees. -- Supervisor's Personnel N ew sletter Bureau of B usiness P ractice, D ec. 7, 1953 29.