Document reQO0jEajOz5wRXZaVvKDDR1a

* 'industrial Hygiene Digest V July, 1956 evidence of previous infection. Coal-mine dust alone produced no fibrosis. The combination of bacilli and dust produced tuberculous cavities involving large areas of lung tissue, and killed the guinea pigs. -- Am. Rev. Tuberc. 910 Experimental Infective Tuberculosis. 4. Massive Pulmonary Fibrosis Produced by CoalMine Dust and Isoniazid- Resistant Tubercle Bacilli of Low Virulence. S. H. Zaidi, C. V. Harrison, E. J. King, and D. A. Mitchison. Brit. J. Expth"PathoL 36, 553-559 (Dec. 1955). The effects of intratracheal injection of coal-mine dust, a catalase-negative iso- niazid-resistant strain of tubercle bacilli of low virulence, and a combination of dust and bacilli were studied in the lungs of guinea pigs. The bacilli alone produced lesions which tended to disappear after 90 days, and the only evidence of tuberculosis at 300 days was a few calcified nodules in some of the lungs. While coal-mine dust itself produced no pul monary fibrosis, the combined action of the dust and bacilli produced massi ve pulmonary fibrosis. In its early stages, the fibrosis was composed mainly of thick reticuiin fibers and collagen, but later1 more collagen was formed. Serial cultures of the lungs injected with coal dust and bacilli yielded growth of tubercle bacilli up to, but not beyond, 120 days. The largest number of organisms was found at 30 days. In animals Infected with bacilli alone, no growth could be obtained from lung cultures other than those from guinea pigs killed one day after injection. -- Am. Rev. Tuberc. 911 Costal Pleura and Pleural Adhesion Silicotic Pigmentation. D. Schwenkenbecher. Tuberkulosearzt 9, 592-595 (Oct. 1955). German. A pneumothorax for cavernous tuberculous disease was induced in a patient who had worked as a bricklayer for fourteen years. During a pneumonolysis, a silicotic deposit was observed in the pleural adhesions as well as in the costal pleura. The suspicion of sllicotuberculosis was verified by biopsy following eventual lobectomy. Silicotic deposits in the costal pleura are rare. They are usually localized in the neighborhood of the pleuropulmonary adhesions and are believed to come from the lymphatic system. In the present case the chest roentgenogram gave no indication of silicotuberculosis. -- Am. Rev. Tuberc. 912 Roentgenographic Complications of Pulmonary Asbestosis. G. Jacob and H. Bohlig. Fortschr. Gebiete Rontgenstrahlen 83, 515-525 (Oct. 1955). German. Over a period of approximately twenty years, 343 cases of asbestosis, 130 in women and 213 in men, were observed in Dresden, a center for industries using asbestos. The most common complications were pleural thickening, compensatory emphysema, and nonspecific peribronchial, peribronchiectatlc, and bronchopneumonic inflammations. Pleural changes were found in 49 per cent of the cases, 5 per cent of which had extensive, irregu- ' larly shaped calcifications. Active pulmonary tuberculosis was present in 4.4 per cent of the cases; bronchogenic cancer was not more frequent than in the general population but, when present, was found relatively often in the lower lobe. - Am. Rev. Tuberc. P HYSICAL ASPECTS OF THE ENVIRONMENT 913 Industrial Noise and How to Deal with It. H. A. Carter. Arch. Phys. Med. 37, 152-158 (Mar. 1956). This paper deals briefly with noise sources, dangerous noise levels, noise measurement, effects on hearing, protection, noise reduction, and medico-legal aspects. 19.