Document B8RXgMMq686LYy2aoLX6VG1wj

FILE NAME: Electrical Insulation (ELEC) DATE: 1947 DOC#: ELEC006 DOCUMENT DESCRIPTION: Book Excerpt DISEASES of the CHEST With Emphasis on X-ray Diagnosis By ELI H. RUBIN, M.D., F.A.G.P., F.C.C.P. Clinical Professor of Medicine, New York Medical College, New York; Director of Medicine, Seton Hospital, New York; Visiting Physician in Chest Diseases, Morrisania City Hospital, New York; Attending Physician. Division of Pulmonary Diseases, Montefiore Hospital and Country Sanatorium, New York: Associate Physician in Chest Diseases, Lebanon Hospital, New York. The Principles of Surgical Treatment By MORRIS RUBIN, M.D., D.S., F.A.C.S. Clinical Instructor in Surgery, Mew York Medical College, New York; Active Consultant in Thoracic Surgery, Fordham Hospital, New York; Visiting Surgeon, Seton Hospital, New York; Associate Visiting Thoracic Surgeon, Morrisania City and Triboro Hospitals, New York; Adjunct Thoracic Surgeon, Montefiore Hospital, New York. 355 ILLU STRATIO NS W IT H 24 PLATES IN COLOR W. B. SAUN D ERS COMPANY PHILADELPHIA & LONDON 348 DISEASES OF THE LUNGS AND BRONCHI roentgen examinations facilitate the detection of incipient stages of the disease. ASBESTOSIS Asbestos is a hydrated silicate of magnesium in combination with traces of iron, nickel, calcium and aluminum. The substance is mined in many parts of the world, including Canada, where most of the American supply (chrysotile) is obtained. Mined asbestos comes in long, thin, fibrous strands which can be spun or woven. Its pliable texture and high resistance to heat and chemicals make asbestos an important industrial product in the manu facture of mattresses, brake-lining, fire-proof ing material, electrical insulation, in jacketing boilers and steam pipes, and in a variety of building fixtures. Although the dust hazard associated with the asbestos industry does not nearly compare in prevalence with that of the silica industry, the rapid growth of the former puts asbestosis among the important forms of dust diseases. Inhaled asbestos fibers range in size from 10 to 00 microns or more. Their action on the lungs is mechanical rather than chemical. The large particles, unable to enter the alveoli, lodge in the lumen and obstruct the respira tory bronchioles. Atelectasis of the distal alve oli is followed by a fibrotic reaction in the collapsed tissue. N'onobstructed alveoli under go compensatory emphysema. Contrary to that seen in silicosis, there is practically no nodulation unless silica is mixed with the asbestos dust. The hilar lymph nodes are not much enlarged for the reason that the lym phatics are not actively engaged in the patho logic process. The gross appearance of the lung is charac terized by scattered areas of diffuse fibrosis, affecting chiefly the lower lobes, emphysema of the uninvolved parts and intense pleuritis. Depending on the extent of coexisting anthracosis and silicosis, there are associated changes and pigmentation of the lungs and lymph nodes. Infection with pyogenic organisms and tubercle bacilli modify the pathology. Tuber culosis has been found in about one-third of the autopsied cases, but there is some doubt as to whether asbestosis per se favors the development of tuberculosis, or whether vul nerability to tuberculosis is primarily due to poor working conditions and incidental factors. A striking feature of the pathology is the presence of "asbestos bodies" seen on histo logic examination of lung tissue. These golden yellow or brown bodies have been shown by Gloyne to be composed of a central core of asbestos fibers, covered by a layer of ironcontaining material which is believed to be de rived from blood pigment of the tissues. Asbes tos bodies may be found in the sputum of asbestos workers, but their presence does not necessarily indicate lung disease. The roentgen appearance of early asbestosis is not revealing. Advanced disease often shows distinguishing characteristics. The fine pulmo nary fibrosis, patchy areas of interspersed em physema and overlying pleuritis are reflected roentgenologically in a "ground-glass" appear ance of a uniform quality, in places showing denser opacities which, however, seldom as sume the nodulation of silicosis (Figs. 183, 184). The lower portions of the lungs are chiefly involved. A marked pleural reac tion manifests itself in obliteration of the costophrenic sinuses, an unevenness of the diaphragm and a felted or "porcupine" appear ance at the periphery of the cardiac silhou ette, the last caused by pleuropericardial adhesions. The onset of the disease is insidious with gradual increase in cough, expectoration, dyspnea, loss of weight and, in time, inability to work. The physical examination is not re vealing. Wood and Gloyne draw attention to a peculiar earthy complexion of the face and a slight, violet tinge in jfehe cheeks and lips of some individuals. Occasionally, asbestos corns occur in the s k in ^ th e hands caused by the penetration of asbestos fibers into the superfi cial epidermis. It takes, on the average, be tween five to ten years for asbestosis to de velop. Whether the disease can progress after contact is broken with asbestos dust is still unsettled. Death results from tuberculous or nontuberculous infection, congestive heart disease or other intercurrent diseases. The measures listed for the prevention of silicosis apply also to asbestosis. Several other silicates have been reported to cause pneumonoconiosis. Fullers' earth, which is used extensively in bleaching fats and oils, has been found to cause pathologic changes in the lungs with symptoms similar to those seen in silicosis. Beryllium dust, a sili cate compound, used in the manufacture of FILE NAME: Electrical Insulation (ELEC) DATE: 1947 DOC#: ELEC006 DOCUMENT DESCRIPTION: Book Excerpt DISEASES of the CHEST With Emphasis on X-ray Diagnosis By ELI H. RUBIN, M.D., F.A.G.P., F.C.G.P. Clinical Professor of Medicine, New York Medical College, New York; Director of Medicine, Seton Hospital, New York; Visiting Physician in Chest Diseases, Morrisania City Hospital, New York; Attending Physician. Division of Pulmonary Diseases, Monlefiore Hospital and Country Sanatorium, New York: Associate Physician in Chest Diseases, Lebanon Hospital, New York. The Principles of Surgical Treatment By MORRIS RUBIN, M.D., D.S., F.A.C.S. Clinical Instructor in Surgery, Mew York Medical College, New York; Active Consultant in Thoracic Surgery, Fordham Hospital, New York; Visiting Surgeon, Seton Hospital, New York; Associate Visiting Thoracic Surgeon, Morrisania City and Triboro Hospitals, New York; Adjunct Thoracic Surgeon, Montefiore Hospital, New York. 355 ILLU STRATIO N S W ITH 24 PLATES IN COLOR W. B. SA U N D ERS COMPANY PHILADELPHIA & LONDON 348 DISEASES OF THE LUNGS AND BRONCHI roentgen examinations facilitate the detection of incipient stages of the disease. ASBESTOSIS Asbestos is a hydrated silicate of magnesium in combination with traces of iron, nickel, calcium and aluminum. The substance is mined in many parts of the world, including Canada, where most of the American supply (chrysotile) is obtained. Mined asbestos comes in long, thin, fibrous strands which can be spun or woven. Its pliable texture and high resistance to heat and chemicals make asbestos an important industrial product in the manu facture of mattresses, brake-lining, fire-proof ing material, electrical insulation, in jacketing boilers and steam pipes, and in a variety of building fixtures. Although the dust hazard associated with the asbestos industry does not nearly compare in prevalence with that of the silica industry, the rapid growth of the former puts asbestosis among the important forms of dust diseases. Inhaled asbestos fibers range in size from 10 to OO microns or more. Their action on the lungs is mechanical rather than chemical. The large particles, unable to enter the alveoli, lodge in the lumen and obstruct the respira tory bronchioles. Atelectasis of the distal alve oli is followed by a fibrotic reaction in the collapsed tissue. Nonobstructed alveoli under go compensatory emphysema. Contrary to that seen in silicosis, there is practically no nodulation unless silica is mixed with the asbestos dust. The hilar lymph nodes are not much enlarged for the reason that the lym phatics are not actively engaged in the patho logic process. The gross appearance of the lung is charac terized by scattered areas of diffuse fibrosis, affecting chiefly the lower lobes, emphysema of the uninvolved parts and intense pleuritis. Depending on the extent of coexisting anthracosis and silicosis, there are associated changes and pigmentation of the lungs and lymph nodes. Infection with pyogenic organisms and tubercle bacilli modify the pathology. Tuber culosis has been found in about one-third of the autopsied cases, but there is some doubt as to whether asbestosis per se favors the development of tuberculosis, or whether vul nerability to tuberculosis is primarily due to poor working conditions and incidental factors. A striking feature of the pathology is the presence of "asbestos bodies" seen on histo logic examination of lung tissue. These golden yellow' or brown bodies have been shown by Gloyne to be composed of a central core of asbestos fibers, covered by a layer of iron- containing material which is believed to be de rived from blood pigment of the tissues. Asbes tos bodies may be found in the sputum of asbestos workers, but their presence does not necessarily indicate lung disease. The roentgen appearance of early asbestosis is not revealing. Advanced disease often shows distinguishing characteristics. The fine pulmo nary fibrosis, patchy areas of interspersed em physema and overlying pleuritis are reflected roentgenologically in a "ground-glass" appear ance of a uniform quality, in places showing denser opacities which, however, seldom as sume the nodulation of silicosis (Figs. 183, 184). The lower portions of the lungs are chiefly involved. A marked pleural reac tion manifests itself in obliteration of the costophrenic sinuses, an unevenness of the diaphragm and a felted or "porcupine" appear ance at the periphery of the cardiac silhou ette, the last caused by pleuropericardial adhesions. The onset of the disease is insidious with gradual increase in cough, expectoration, dyspnea, loss of weight and, in time, inability to work. The physical examination is not re vealing. Wood and Gloyne draw attention to a peculiar earthy complexion of the face and a slight, violet tinge in the cheeks and lips of some individuals. Occasionally, asbestos corns occur in the skin pt'the hands caused by the penetration of asbestos fibers into the superfi cial epidermis. It takes, on the average, be tween five to ten years for asbestosis to de velop. Whether the disease can progress after contact is broken with asbestos dust is still unsettled. Death results from tuberculous or nontuberculous infection, congestive heart disease or other intercurrent diseases. The measures listed for the prevention of silicosis apply also to asbestosis. Several other silicates have been reported to cause pneumonoconiosis. Fullers' earth, which is used extensively in bleaching fats and oils, has been found to cause pathologic changes in the lungs with symptoms similar to those seen in silicosis. Beryllium dust, a sili cate compound, used in the manufacture of